| Message ID | 20180719152930.3715-2-boris.brezillon@bootlin.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Add the I3C subsystem | expand |
On 7/19/2018 9:29 AM, Boris Brezillon wrote: > Add core infrastructure to support I3C in Linux and document it. > > This infrastructure is not complete yet and will be extended over > time. > > There are a few design choices that are worth mentioning because they > impact the way I3C device drivers can interact with their devices: > > - all functions used to send I3C/I2C frames must be called in > non-atomic context. Mainly done this way to ease implementation, but > this is still open to discussion. Please let me know if you think > it's worth considering an asynchronous model here > - the bus element is a separate object and is not implicitly described > by the master (as done in I2C). The reason is that I want to be able > to handle multiple master connected to the same bus and visible to > Linux. > In this situation, we should only have one instance of the device and > not one per master, and sharing the bus object would be part of the > solution to gracefully handle this case. > I'm not sure we will ever need to deal with multiple masters > controlling the same bus and exposed under Linux, but separating the > bus and master concept is pretty easy, hence the decision to do it > like that. > The other benefit of separating the bus and master concepts is that > master devices appear under the bus directory in sysfs. > - I2C backward compatibility has been designed to be transparent to I2C > drivers and the I2C subsystem. The I3C master just registers an I2C > adapter which creates a new I2C bus. I'd say that, from a > representation PoV it's not ideal because what should appear as a > single I3C bus exposing I3C and I2C devices here appears as 2 > different busses connected to each other through the parenting (the > I3C master is the parent of the I2C and I3C busses). > On the other hand, I don't see a better solution if we want something > that is not invasive. > > Missing features in this preliminary version: > - I3C HDR modes are not supported > - no support for multi-master and the associated concepts (mastership > handover, support for secondary masters, ...) > - I2C devices can only be described using DT because this is the only > use case I have. However, the framework can easily be extended with > ACPI and board info support > - I3C slave framework. This has been completely omitted, but shouldn't > have a huge impact on the I3C framework because I3C slaves don't see > the whole bus, it's only about handling master requests and generating > IBIs. Some of the struct, constant and enum definitions could be > shared, but most of the I3C slave framework logic will be different > > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> > --- > Changes in v6: > - Add I3C/I2C dev descriptors to simplify I3C driver controllers when > migrating resources from on I3C device slot to anoter > - Add I3C error codes and return them when doing SDR/priv and CCC > transfers. This allows us to properly detect when no devices acked > a CCC command, which in some cases is a valid situation (no I3C > devices on the bus) > - Remove __packed specifiers where unneeded > - Allocate all IBI slots in one call using kcalloc() > > Changes in v5: > - Rename the address sysfs entry into dynamic_address to clarify things > - Document that we expect buffers passed to i3c_device_do_priv_xfers() > to be DMA-able > - Fix DEFSLVS CCC command > - s/2017/2018/ in copyright headers > - Fix SPDX header in internals.h > - Fix coding style issues > > Changes in v4: > - none > > Changes in v3: > - Fix locking issues > - Explicitly include a bunch of headers (reported by Randy Dunlap) > - Rename {i2c,i3c}-scl-frequency DT prop into {i2c,i3c}-scl-hz > - Do not use BIT() macro in mod_devicetable.h > - Fix typos > - Fix/enhance some kernel doc headers > - Rework the bus initialization code to simplify master drivers > - Assign dynamic address with SETDASA if the device has a static > address and the DT has a valid assigned-address property > - Rework the LVR extraction in DT parsing code > - Add code to detect when a device is re-attached to the bus after > losing its dynamic address. In this case we know try to re-assign the > old address, and most importantly, the I3C device driver sees the same > device instance, not a new one > - Add an ->i2c_funcs() hook to let the master declare which I2C features > it supports > - Unexport a few functions > - Remove support for HDR mode since we have no real user yet > > Changes in v2: > - Fix a bunch of mistake I made with the device model (pointed by GKH) > - Move the documentation out of this commit (pointed by GKH) > - only source drivers/i3c/master/Kconfig when CONFIG_I3C is enabled > (pointed by GKH) > - Add IBI infrastructure > - Add helpers to ease support for Hot Join (most of the logic is > delegated to I3C controller drivers) > - move the doc out of this commit to improve readability > - Fix a few bugs in device probing/remove (detected after trying to > load/unload modules in various orders) > - Add a module_i3c_i2c_driver() macro to ease integration of drivers > for devices that support both I3C and I2C mode > --- > drivers/Kconfig | 2 + > drivers/Makefile | 2 +- > drivers/i3c/Kconfig | 24 + > drivers/i3c/Makefile | 4 + > drivers/i3c/core.c | 606 ++++++++++++ > drivers/i3c/device.c | 233 +++++ > drivers/i3c/internals.h | 36 + > drivers/i3c/master.c | 2058 > +++++++++++++++++++++++++++++++++++++++ > drivers/i3c/master/Kconfig | 0 > drivers/i3c/master/Makefile | 0 > include/linux/i3c/ccc.h | 385 ++++++++ > include/linux/i3c/device.h | 331 +++++++ > include/linux/i3c/master.h | 652 +++++++++++++ > include/linux/mod_devicetable.h | 17 + > 14 files changed, 4349 insertions(+), 1 deletion(-) > create mode 100644 drivers/i3c/Kconfig > create mode 100644 drivers/i3c/Makefile > create mode 100644 drivers/i3c/core.c > create mode 100644 drivers/i3c/device.c > create mode 100644 drivers/i3c/internals.h > create mode 100644 drivers/i3c/master.c > create mode 100644 drivers/i3c/master/Kconfig > create mode 100644 drivers/i3c/master/Makefile > create mode 100644 include/linux/i3c/ccc.h > create mode 100644 include/linux/i3c/device.h > create mode 100644 include/linux/i3c/master.h > > diff --git a/drivers/Kconfig b/drivers/Kconfig > index 95b9ccc08165..80f6aebc896f 100644 > --- a/drivers/Kconfig > +++ b/drivers/Kconfig > @@ -55,6 +55,8 @@ source "drivers/char/Kconfig" > > source "drivers/i2c/Kconfig" > > +source "drivers/i3c/Kconfig" > + > source "drivers/spi/Kconfig" > > source "drivers/spmi/Kconfig" > diff --git a/drivers/Makefile b/drivers/Makefile > index 24cd47014657..999239dc29d4 100644 > --- a/drivers/Makefile > +++ b/drivers/Makefile > @@ -111,7 +111,7 @@ obj-$(CONFIG_SERIO) += input/serio/ > obj-$(CONFIG_GAMEPORT) += input/gameport/ > obj-$(CONFIG_INPUT) += input/ > obj-$(CONFIG_RTC_LIB) += rtc/ > -obj-y += i2c/ media/ > +obj-y += i2c/ i3c/ media/ > obj-$(CONFIG_PPS) += pps/ > obj-y += ptp/ > obj-$(CONFIG_W1) += w1/ > diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig > new file mode 100644 > index 000000000000..30a441506f61 > --- /dev/null > +++ b/drivers/i3c/Kconfig > @@ -0,0 +1,24 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +menuconfig I3C > + tristate "I3C support" > + select I2C > + help > + I3C is a serial protocol standardized by the MIPI alliance. > + > + It's supposed to be backward compatible with I2C while providing > + support for high speed transfers and native interrupt support > + without the need for extra pins. > + > + The I3C protocol also standardizes the slave device types and is > + mainly designed to communicate with sensors. > + > + If you want I3C support, you should say Y here and also to the > + specific driver for your bus adapter(s) below. > + > + This I3C support can also be built as a module. If so, the module > + will be called i3c. > + > +if I3C > +source "drivers/i3c/master/Kconfig" > +endif # I3C > diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile > new file mode 100644 > index 000000000000..3b6d1502d6e6 > --- /dev/null > +++ b/drivers/i3c/Makefile > @@ -0,0 +1,4 @@ > +# SPDX-License-Identifier: GPL-2.0 > +i3c-y := core.o device.o master.o > +obj-$(CONFIG_I3C) += i3c.o > +obj-$(CONFIG_I3C) += master/ > diff --git a/drivers/i3c/core.c b/drivers/i3c/core.c > new file mode 100644 > index 000000000000..5c62192ff876 > --- /dev/null > +++ b/drivers/i3c/core.c > @@ -0,0 +1,606 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2018 Cadence Design Systems Inc. > + * > + * Author: Boris Brezillon <boris.brezillon@bootlin.com> > + */ > + > +#include <linux/device.h> > +#include <linux/idr.h> > +#include <linux/init.h> > +#include <linux/list.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of_device.h> > +#include <linux/rwsem.h> > +#include <linux/slab.h> > + > +#include "internals.h" > + > +static DEFINE_IDR(i3c_bus_idr); > +static DEFINE_MUTEX(i3c_core_lock); > + > +/** > + * i3c_bus_maintenance_lock - Lock the bus for a maintenance operation > + * @bus: I3C bus to take the lock on > + * > + * This function takes the bus lock so that no other operations can occur on > + * the bus. This is needed for all kind of bus maintenance operation, like > + * - enabling/disabling slave events > + * - re-triggering DAA > + * - changing the dynamic address of a device > + * - relinquishing mastership > + * - ... > + * > + * The reason for this kind of locking is that we don't want drivers and core > + * logic to rely on I3C device information that could be changed behind their > + * back. > + */ > +void i3c_bus_maintenance_lock(struct i3c_bus *bus) > +{ > + down_write(&bus->lock); > +} > +EXPORT_SYMBOL_GPL(i3c_bus_maintenance_lock); > + > +/** > + * i3c_bus_maintenance_unlock - Release the bus lock after a maintenance > + * operation > + * @bus: I3C bus to release the lock on > + * > + * Should be called when the bus maintenance operation is done. See > + * i3c_bus_maintenance_lock() for more details on what these > maintenance > + * operations are. > + */ > +void i3c_bus_maintenance_unlock(struct i3c_bus *bus) > +{ > + up_write(&bus->lock); > +} > +EXPORT_SYMBOL_GPL(i3c_bus_maintenance_unlock); > + > +/** > + * i3c_bus_normaluse_lock - Lock the bus for a normal operation > + * @bus: I3C bus to take the lock on > + * > + * This function takes the bus lock for any operation that is not a > maintenance > + * operation (see i3c_bus_maintenance_lock() for a non-exhaustive list of > + * maintenance operations). Basically all communications with I3C devices > are > + * normal operations (HDR, SDR transfers or CCC commands that do not > change bus > + * state or I3C dynamic address). > + * > + * Note that this lock is not guaranteeing serialization of normal operations. > + * In other words, transfer requests passed to the I3C master can be > submitted > + * in parallel and I3C master drivers have to use their own locking to make > + * sure two different communications are not inter-mixed, or access to the > + * output/input queue is not done while the engine is busy. > + */ > +void i3c_bus_normaluse_lock(struct i3c_bus *bus) > +{ > + down_read(&bus->lock); > +} > +EXPORT_SYMBOL_GPL(i3c_bus_normaluse_lock); > + > +/** > + * i3c_bus_normaluse_unlock - Release the bus lock after a normal > operation > + * @bus: I3C bus to release the lock on > + * > + * Should be called when a normal operation is done. See > + * i3c_bus_normaluse_lock() for more details on what these normal > operations > + * are. > + */ > +void i3c_bus_normaluse_unlock(struct i3c_bus *bus) > +{ > + up_read(&bus->lock); > +} > +EXPORT_SYMBOL_GPL(i3c_bus_normaluse_unlock); > + > +static ssize_t bcr_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cdev->bus); > + ret = sprintf(buf, "%x\n", i3cdev->desc->info.bcr); > + i3c_bus_normaluse_unlock(i3cdev->bus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(bcr); > + > +static ssize_t dcr_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cdev->bus); > + ret = sprintf(buf, "%x\n", i3cdev->desc->info.dcr); > + i3c_bus_normaluse_unlock(i3cdev->bus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(dcr); > + > +static ssize_t pid_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cdev->bus); > + ret = sprintf(buf, "%llx\n", i3cdev->desc->info.pid); > + i3c_bus_normaluse_unlock(i3cdev->bus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(pid); > + > +static ssize_t dynamic_address_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cdev->bus); > + ret = sprintf(buf, "%02x\n", i3cdev->desc->info.dyn_addr); > + i3c_bus_normaluse_unlock(i3cdev->bus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(dynamic_address); > + > +static const char * const hdrcap_strings[] = { > + "hdr-ddr", "hdr-tsp", "hdr-tsl", > +}; > + > +static ssize_t hdrcap_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + ssize_t offset = 0, ret; > + unsigned long caps; > + int mode; > + > + i3c_bus_normaluse_lock(i3cdev->bus); > + caps = i3cdev->desc->info.hdr_cap; > + for_each_set_bit(mode, &caps, 8) { > + if (mode >= ARRAY_SIZE(hdrcap_strings)) > + break; > + > + if (!hdrcap_strings[mode]) > + continue; > + > + ret = sprintf(buf + offset, offset ? " %s" : "%s", > + hdrcap_strings[mode]); > + if (ret < 0) > + goto out; > + > + offset += ret; > + } > + > + ret = sprintf(buf + offset, "\n"); > + if (ret < 0) > + goto out; > + > + ret = offset + ret; > + > +out: > + i3c_bus_normaluse_unlock(i3cdev->bus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(hdrcap); > + > +static struct attribute *i3c_device_attrs[] = { > + &dev_attr_bcr.attr, > + &dev_attr_dcr.attr, > + &dev_attr_pid.attr, > + &dev_attr_dynamic_address.attr, > + &dev_attr_hdrcap.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(i3c_device); > + > +static int i3c_device_uevent(struct device *dev, struct kobj_uevent_env > *env) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + struct i3c_device_info devinfo; > + u16 manuf, part, ext; > + > + i3c_device_get_info(i3cdev, &devinfo); > + manuf = I3C_PID_MANUF_ID(devinfo.pid); > + part = I3C_PID_PART_ID(devinfo.pid); > + ext = I3C_PID_EXTRA_INFO(devinfo.pid); > + > + if (I3C_PID_RND_LOWER_32BITS(devinfo.pid)) > + return add_uevent_var(env, > "MODALIAS=i3c:dcr%02Xmanuf%04X", > + devinfo.dcr, manuf); > + > + return add_uevent_var(env, > + > "MODALIAS=i3c:dcr%02Xmanuf%04Xpart%04xext%04x", > + devinfo.dcr, manuf, part, ext); > +} > + > +const struct device_type i3c_device_type = { > + .groups = i3c_device_groups, > + .uevent = i3c_device_uevent, > +}; > + > +const struct device_type i3c_master_type = { > + .groups = i3c_device_groups, > +}; > + > +static const struct i3c_device_id * > +i3c_device_match_id(struct i3c_device *i3cdev, > + const struct i3c_device_id *id_table) > +{ > + struct i3c_device_info devinfo; > + const struct i3c_device_id *id; > + > + i3c_device_get_info(i3cdev, &devinfo); > + > + /* > + * The lower 32bits of the provisional ID is just filled with a random > + * value, try to match using DCR info. > + */ > + if (!I3C_PID_RND_LOWER_32BITS(devinfo.pid)) { > + u16 manuf = I3C_PID_MANUF_ID(devinfo.pid); > + u16 part = I3C_PID_PART_ID(devinfo.pid); > + u16 ext_info = I3C_PID_EXTRA_INFO(devinfo.pid); > + > + /* First try to match by manufacturer/part ID. */ > + for (id = id_table; id->match_flags != 0; id++) { > + if ((id->match_flags & > I3C_MATCH_MANUF_AND_PART) != > + I3C_MATCH_MANUF_AND_PART) > + continue; > + > + if (manuf != id->manuf_id || part != id->part_id) > + continue; > + > + if ((id->match_flags & I3C_MATCH_EXTRA_INFO) && > + ext_info != id->extra_info) > + continue; > + > + return id; > + } > + } > + > + /* Fallback to DCR match. */ > + for (id = id_table; id->match_flags != 0; id++) { > + if ((id->match_flags & I3C_MATCH_DCR) && > + id->dcr == devinfo.dcr) > + return id; > + } > + > + return NULL; > +} > + > +static int i3c_device_match(struct device *dev, struct device_driver *drv) > +{ > + struct i3c_device *i3cdev; > + struct i3c_driver *i3cdrv; > + > + if (dev->type != &i3c_device_type) > + return 0; > + > + i3cdev = dev_to_i3cdev(dev); > + i3cdrv = drv_to_i3cdrv(drv); > + if (i3c_device_match_id(i3cdev, i3cdrv->id_table)) > + return 1; > + > + return 0; > +} > + > +static int i3c_device_probe(struct device *dev) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + struct i3c_driver *driver = drv_to_i3cdrv(dev->driver); > + > + return driver->probe(i3cdev); > +} > + > +static int i3c_device_remove(struct device *dev) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + struct i3c_driver *driver = drv_to_i3cdrv(dev->driver); > + int ret; > + > + ret = driver->remove(i3cdev); > + if (ret) > + return ret; > + > + i3c_device_free_ibi(i3cdev); > + > + return ret; > +} > + > +struct bus_type i3c_bus_type = { > + .name = "i3c", > + .match = i3c_device_match, > + .probe = i3c_device_probe, > + .remove = i3c_device_remove, > +}; > + > +enum i3c_addr_slot_status i3c_bus_get_addr_slot_status(struct i3c_bus > *bus, > + u16 addr) > +{ > + int status, bitpos = addr * 2; > + > + if (addr > I2C_MAX_ADDR) > + return I3C_ADDR_SLOT_RSVD; > + > + status = bus->addrslots[bitpos / BITS_PER_LONG]; > + status >>= bitpos % BITS_PER_LONG; > + > + return status & I3C_ADDR_SLOT_STATUS_MASK; > +} > + > +void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr, > + enum i3c_addr_slot_status status) > +{ > + int bitpos = addr * 2; > + unsigned long *ptr; > + > + if (addr > I2C_MAX_ADDR) > + return; > + > + ptr = bus->addrslots + (bitpos / BITS_PER_LONG); > + *ptr &= ~(I3C_ADDR_SLOT_STATUS_MASK << (bitpos % > BITS_PER_LONG)); > + *ptr |= status << (bitpos % BITS_PER_LONG); > +} > + > +bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr) > +{ > + enum i3c_addr_slot_status status; > + > + status = i3c_bus_get_addr_slot_status(bus, addr); > + > + return status == I3C_ADDR_SLOT_FREE; > +} > + > +int i3c_bus_get_free_addr(struct i3c_bus *bus, u8 start_addr) > +{ > + enum i3c_addr_slot_status status; > + u8 addr; > + > + for (addr = start_addr; addr < I3C_MAX_ADDR; addr++) { > + status = i3c_bus_get_addr_slot_status(bus, addr); > + if (status == I3C_ADDR_SLOT_FREE) > + return addr; > + } > + > + return -ENOMEM; > +} > + > +static void i3c_bus_init_addrslots(struct i3c_bus *bus) > +{ > + int i; > + > + /* Addresses 0 to 7 are reserved. */ > + for (i = 0; i < 8; i++) > + i3c_bus_set_addr_slot_status(bus, i, > I3C_ADDR_SLOT_RSVD); > + > + /* > + * Reserve broadcast address and all addresses that might collide > + * with the broadcast address when facing a single bit error. > + */ > + i3c_bus_set_addr_slot_status(bus, I3C_BROADCAST_ADDR, > + I3C_ADDR_SLOT_RSVD); > + for (i = 0; i < 7; i++) > + i3c_bus_set_addr_slot_status(bus, I3C_BROADCAST_ADDR ^ > BIT(i), > + I3C_ADDR_SLOT_RSVD); > +} > + > +static const char * const i3c_bus_mode_strings[] = { > + [I3C_BUS_MODE_PURE] = "pure", > + [I3C_BUS_MODE_MIXED_FAST] = "mixed-fast", > + [I3C_BUS_MODE_MIXED_SLOW] = "mixed-slow", > +}; > + > +static ssize_t mode_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cbus); > + if (i3cbus->mode < 0 || > + i3cbus->mode > ARRAY_SIZE(i3c_bus_mode_strings) || > + !i3c_bus_mode_strings[i3cbus->mode]) > + ret = sprintf(buf, "unknown\n"); > + else > + ret = sprintf(buf, "%s\n", i3c_bus_mode_strings[i3cbus- > >mode]); > + i3c_bus_normaluse_unlock(i3cbus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(mode); > + > +static ssize_t current_master_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cbus); > + ret = sprintf(buf, "%d-%llx\n", i3cbus->id, > + i3cbus->cur_master->info.pid); > + i3c_bus_normaluse_unlock(i3cbus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(current_master); > + > +static ssize_t i3c_scl_frequency_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cbus); > + ret = sprintf(buf, "%ld\n", i3cbus->scl_rate.i3c); > + i3c_bus_normaluse_unlock(i3cbus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(i3c_scl_frequency); > + > +static ssize_t i2c_scl_frequency_show(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); > + ssize_t ret; > + > + i3c_bus_normaluse_lock(i3cbus); > + ret = sprintf(buf, "%ld\n", i3cbus->scl_rate.i2c); > + i3c_bus_normaluse_unlock(i3cbus); > + > + return ret; > +} > +static DEVICE_ATTR_RO(i2c_scl_frequency); > + > +static struct attribute *i3c_busdev_attrs[] = { > + &dev_attr_mode.attr, > + &dev_attr_current_master.attr, > + &dev_attr_i3c_scl_frequency.attr, > + &dev_attr_i2c_scl_frequency.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(i3c_busdev); > + > +static void i3c_busdev_release(struct device *dev) > +{ > + struct i3c_bus *bus = container_of(dev, struct i3c_bus, dev); > + > + WARN_ON(!list_empty(&bus->devs.i2c) || !list_empty(&bus- > >devs.i3c)); > + > + mutex_lock(&i3c_core_lock); > + idr_remove(&i3c_bus_idr, bus->id); > + mutex_unlock(&i3c_core_lock); > + > + of_node_put(bus->dev.of_node); > + kfree(bus); > +} > + > +static const struct device_type i3c_busdev_type = { > + .groups = i3c_busdev_groups, > +}; > + > +void i3c_bus_unref(struct i3c_bus *bus) > +{ > + put_device(&bus->dev); > +} > + > +struct i3c_bus *i3c_bus_create(struct device *parent) > +{ > + struct i3c_bus *i3cbus; > + int ret; > + > + i3cbus = kzalloc(sizeof(*i3cbus), GFP_KERNEL); > + if (!i3cbus) > + return ERR_PTR(-ENOMEM); > + > + init_rwsem(&i3cbus->lock); > + INIT_LIST_HEAD(&i3cbus->devs.i2c); > + INIT_LIST_HEAD(&i3cbus->devs.i3c); > + i3c_bus_init_addrslots(i3cbus); > + i3cbus->mode = I3C_BUS_MODE_PURE; > + i3cbus->dev.parent = parent; > + i3cbus->dev.of_node = of_node_get(parent->of_node); > + i3cbus->dev.bus = &i3c_bus_type; > + i3cbus->dev.type = &i3c_busdev_type; > + i3cbus->dev.release = i3c_busdev_release; > + > + mutex_lock(&i3c_core_lock); > + ret = idr_alloc(&i3c_bus_idr, i3cbus, 0, 0, GFP_KERNEL); > + mutex_unlock(&i3c_core_lock); > + if (ret < 0) > + goto err_free_bus; > + > + i3cbus->id = ret; > + device_initialize(&i3cbus->dev); > + > + return i3cbus; > + > +err_free_bus: > + kfree(i3cbus); > + > + return ERR_PTR(ret); > +} > + > +void i3c_bus_unregister(struct i3c_bus *bus) > +{ > + device_unregister(&bus->dev); > +} > + > +int i3c_bus_register(struct i3c_bus *i3cbus) > +{ > + struct i2c_dev_desc *desc; > + > + i3c_bus_for_each_i2cdev(i3cbus, desc) { > + switch (desc->boardinfo->lvr & I3C_LVR_I2C_INDEX_MASK) { > + case I3C_LVR_I2C_INDEX(0): > + if (i3cbus->mode < I3C_BUS_MODE_MIXED_FAST) > + i3cbus->mode = > I3C_BUS_MODE_MIXED_FAST; > + break; > + > + case I3C_LVR_I2C_INDEX(1): > + case I3C_LVR_I2C_INDEX(2): > + if (i3cbus->mode < I3C_BUS_MODE_MIXED_SLOW) > + i3cbus->mode = > I3C_BUS_MODE_MIXED_SLOW; > + break; > + > + default: > + return -EINVAL; > + } > + } > + > + if (!i3cbus->scl_rate.i3c) > + i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; > + > + if (!i3cbus->scl_rate.i2c) { > + if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW) > + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; > + else > + i3cbus->scl_rate.i2c = > I3C_BUS_I2C_FM_PLUS_SCL_RATE; > + } > + > + /* > + * I3C/I2C frequency may have been overridden, check that user- > provided > + * values are not exceeding max possible frequency. > + */ > + if (i3cbus->scl_rate.i3c > I3C_BUS_MAX_I3C_SCL_RATE || > + i3cbus->scl_rate.i2c > I3C_BUS_I2C_FM_PLUS_SCL_RATE) { > + return -EINVAL; > + } > + > + dev_set_name(&i3cbus->dev, "i3c-%d", i3cbus->id); > + > + return device_add(&i3cbus->dev); > +} > + > +static int __init i3c_init(void) > +{ > + return bus_register(&i3c_bus_type); > +} > +subsys_initcall(i3c_init); > + > +static void __exit i3c_exit(void) > +{ > + idr_destroy(&i3c_bus_idr); > + bus_unregister(&i3c_bus_type); > +} > +module_exit(i3c_exit); > + > +MODULE_AUTHOR("Boris Brezillon <boris.brezillon@bootlin.com>"); > +MODULE_DESCRIPTION("I3C core"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c > new file mode 100644 > index 000000000000..69cc040c3a1c > --- /dev/null > +++ b/drivers/i3c/device.c > @@ -0,0 +1,233 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2018 Cadence Design Systems Inc. > + * > + * Author: Boris Brezillon <boris.brezillon@bootlin.com> > + */ > + > +#include <linux/atomic.h> > +#include <linux/bug.h> > +#include <linux/completion.h> > +#include <linux/device.h> > +#include <linux/mutex.h> > +#include <linux/slab.h> > + > +#include "internals.h" > + > +/** > + * i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a > + * specific device > + * > + * @dev: device with which the transfers should be done > + * @xfers: array of transfers > + * @nxfers: number of transfers > + * > + * Initiate one or several private SDR transfers with @dev. > + * > + * This function can sleep and thus cannot be called in atomic context. > + * > + * Return: 0 in case of success, a negative error core otherwise. > + */ > +int i3c_device_do_priv_xfers(struct i3c_device *dev, > + struct i3c_priv_xfer *xfers, > + int nxfers) > +{ > + int ret, i; > + > + if (nxfers < 1) > + return 0; > + > + for (i = 0; i < nxfers; i++) { > + if (!xfers[i].len || !xfers[i].data.in) > + return -EINVAL; > + } > + > + i3c_bus_normaluse_lock(dev->bus); > + ret = i3c_dev_do_priv_xfers_locked(dev->desc, xfers, nxfers); > + i3c_bus_normaluse_unlock(dev->bus); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers); > + > +/** > + * i3c_device_get_info() - get I3C device information > + * > + * @dev: device we want information on > + * @info: the information object to fill in > + * > + * Retrieve I3C dev info. > + */ > +void i3c_device_get_info(struct i3c_device *dev, > + struct i3c_device_info *info) > +{ > + if (!info) > + return; > + > + i3c_bus_normaluse_lock(dev->bus); > + if (dev->desc) > + *info = dev->desc->info; > + i3c_bus_normaluse_unlock(dev->bus); > +} > +EXPORT_SYMBOL_GPL(i3c_device_get_info); > + > +/** > + * i3c_device_disable_ibi() - Disable IBIs coming from a specific device > + * @dev: device on which IBIs should be disabled > + * > + * This function disable IBIs coming from a specific device and wait for > + * all pending IBIs to be processed. > + * > + * Return: 0 in case of success, a negative error core otherwise. > + */ > +int i3c_device_disable_ibi(struct i3c_device *dev) > +{ > + int ret = -ENOENT; > + > + i3c_bus_normaluse_lock(dev->bus); > + if (dev->desc) { > + mutex_lock(&dev->desc->ibi_lock); > + ret = i3c_dev_disable_ibi_locked(dev->desc); > + mutex_unlock(&dev->desc->ibi_lock); > + } > + i3c_bus_normaluse_unlock(dev->bus); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(i3c_device_disable_ibi); > + > +/** > + * i3c_device_enable_ibi() - Enable IBIs coming from a specific device > + * @dev: device on which IBIs should be enabled > + * > + * This function enable IBIs coming from a specific device and wait for > + * all pending IBIs to be processed. This should be called on a device > + * where i3c_device_request_ibi() has succeeded. > + * > + * Note that IBIs from this device might be received before this function > + * returns to its caller. > + * > + * Return: 0 in case of success, a negative error core otherwise. > + */ > +int i3c_device_enable_ibi(struct i3c_device *dev) > +{ > + int ret = -ENOENT; > + > + i3c_bus_normaluse_lock(dev->bus); > + if (dev->desc) { > + mutex_lock(&dev->desc->ibi_lock); > + ret = i3c_dev_enable_ibi_locked(dev->desc); > + mutex_unlock(&dev->desc->ibi_lock); > + } > + i3c_bus_normaluse_unlock(dev->bus); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(i3c_device_enable_ibi); > + > +/** > + * i3c_device_request_ibi() - Request an IBI > + * @dev: device for which we should enable IBIs > + * @req: setup requested for this IBI > + * > + * This function is responsible for pre-allocating all resources needed to > + * process IBIs coming from @dev. When this function returns, the IBI is not > + * enabled until i3c_device_enable_ibi() is called. > + * > + * Return: 0 in case of success, a negative error core otherwise. > + */ > +int i3c_device_request_ibi(struct i3c_device *dev, > + const struct i3c_ibi_setup *req) > +{ > + int ret = -ENOENT; > + > + if (!req->handler || !req->num_slots) > + return -EINVAL; > + > + i3c_bus_normaluse_lock(dev->bus); > + if (dev->desc) { > + mutex_lock(&dev->desc->ibi_lock); > + ret = i3c_dev_request_ibi_locked(dev->desc, req); > + mutex_unlock(&dev->desc->ibi_lock); > + } > + i3c_bus_normaluse_unlock(dev->bus); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(i3c_device_request_ibi); > + > +/** > + * i3c_device_free_ibi() - Free all resources needed for IBI handling > + * @dev: device on which you want to release IBI resources > + * > + * This function is responsible for de-allocating resources previously > + * allocated by i3c_device_request_ibi(). It should be called after disabling > + * IBIs with i3c_device_disable_ibi(). > + */ > +void i3c_device_free_ibi(struct i3c_device *dev) > +{ > + i3c_bus_normaluse_lock(dev->bus); > + if (dev->desc) { > + mutex_lock(&dev->desc->ibi_lock); > + i3c_dev_free_ibi_locked(dev->desc); > + mutex_unlock(&dev->desc->ibi_lock); > + } > + i3c_bus_normaluse_unlock(dev->bus); > +} > +EXPORT_SYMBOL_GPL(i3c_device_free_ibi); > + > +/** > + * i3cdev_to_dev() - Returns the device embedded in @i3cdev > + * @i3cdev: I3C device > + * > + * Return: a pointer to a device object. > + */ > +struct device *i3cdev_to_dev(struct i3c_device *i3cdev) > +{ > + return &i3cdev->dev; > +} > +EXPORT_SYMBOL_GPL(i3cdev_to_dev); > + > +/** > + * dev_to_i3cdev() - Returns the I3C device containing @dev > + * @dev: device object > + * > + * Return: a pointer to an I3C device object. > + */ > +struct i3c_device *dev_to_i3cdev(struct device *dev) > +{ > + return container_of(dev, struct i3c_device, dev); > +} > +EXPORT_SYMBOL_GPL(dev_to_i3cdev); > + > +/** > + * i3c_driver_register_with_owner() - register an I3C device driver > + * > + * @drv: driver to register > + * @owner: module that owns this driver > + * > + * Register @drv to the core. > + * > + * Return: 0 in case of success, a negative error core otherwise. > + */ > +int i3c_driver_register_with_owner(struct i3c_driver *drv, struct module > *owner) > +{ > + drv->driver.owner = owner; > + drv->driver.bus = &i3c_bus_type; > + > + return driver_register(&drv->driver); > +} > +EXPORT_SYMBOL_GPL(i3c_driver_register_with_owner); > + > +/** > + * i3c_driver_unregister() - unregister an I3C device driver > + * > + * @drv: driver to unregister > + * > + * Unregister @drv. > + */ > +void i3c_driver_unregister(struct i3c_driver *drv) > +{ > + driver_unregister(&drv->driver); > +} > +EXPORT_SYMBOL_GPL(i3c_driver_unregister); > diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h > new file mode 100644 > index 000000000000..ced88435466f > --- /dev/null > +++ b/drivers/i3c/internals.h > @@ -0,0 +1,36 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2018 Cadence Design Systems Inc. > + * > + * Author: Boris Brezillon <boris.brezillon@bootlin.com> > + */ > + > +#ifndef I3C_INTERNALS_H > +#define I3C_INTERNALS_H > + > +#include <linux/i3c/master.h> > + > +extern struct bus_type i3c_bus_type; > +extern const struct device_type i3c_master_type; > +extern const struct device_type i3c_device_type; > + > +void i3c_bus_unref(struct i3c_bus *bus); > +struct i3c_bus *i3c_bus_create(struct device *parent); > +void i3c_bus_unregister(struct i3c_bus *bus); > +int i3c_bus_register(struct i3c_bus *i3cbus); > +int i3c_bus_get_free_addr(struct i3c_bus *bus, u8 start_addr); > +bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr); > +void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr, > + enum i3c_addr_slot_status status); > +enum i3c_addr_slot_status i3c_bus_get_addr_slot_status(struct i3c_bus > *bus, > + u16 addr); > + > +int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev, > + struct i3c_priv_xfer *xfers, > + int nxfers); > +int i3c_dev_disable_ibi_locked(struct i3c_dev_desc *dev); > +int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev); > +int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev, > + const struct i3c_ibi_setup *req); > +void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev); > +#endif /* I3C_INTERNAL_H */ > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c > new file mode 100644 > index 000000000000..d04e9ff9c850 > --- /dev/null > +++ b/drivers/i3c/master.c > @@ -0,0 +1,2058 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2018 Cadence Design Systems Inc. > + * > + * Author: Boris Brezillon <boris.brezillon@bootlin.com> > + */ > + > +#include <linux/atomic.h> > +#include <linux/bug.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/export.h> > +#include <linux/kernel.h> > +#include <linux/list.h> > +#include <linux/of.h> > +#include <linux/slab.h> > +#include <linux/spinlock.h> > +#include <linux/workqueue.h> > + > +#include "internals.h" > + > +static struct i3c_master_controller * > +i2c_adapter_to_i3c_master(struct i2c_adapter *adap) > +{ > + return container_of(adap, struct i3c_master_controller, i2c); > +} > + > +static struct i2c_adapter * > +i3c_master_to_i2c_adapter(struct i3c_master_controller *master) > +{ > + return &master->i2c; > +} > + > +static void i3c_master_free_i2c_dev(struct i2c_dev_desc *dev) > +{ > + kfree(dev); > +} > + > +static struct i2c_dev_desc * > +i3c_master_alloc_i2c_dev(struct i3c_master_controller *master, > + const struct i2c_dev_boardinfo *boardinfo) > +{ > + struct i2c_dev_desc *dev; > + > + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > + if (!dev) > + return ERR_PTR(-ENOMEM); > + > + dev->common.master = master; > + dev->boardinfo = boardinfo; > + > + return dev; > +} > + > +static int i3c_master_send_ccc_cmd_locked(struct i3c_master_controller > *master, > + struct i3c_ccc_cmd *cmd) > +{ > + int ret; > + > + if (!cmd || !master) > + return -EINVAL; > + > + if (WARN_ON(master->init_done && > + !rwsem_is_locked(&master->bus->lock))) > + return -EINVAL; > + > + if (!master->ops->send_ccc_cmd) > + return -ENOTSUPP; > + > + if ((cmd->id & I3C_CCC_DIRECT) && (!cmd->dests || !cmd->ndests)) > + return -EINVAL; > + > + if (master->ops->supports_ccc_cmd && > + !master->ops->supports_ccc_cmd(master, cmd)) > + return -ENOTSUPP; > + > + ret = master->ops->send_ccc_cmd(master, cmd); > + if (ret) { > + if (cmd->err != I3C_ERROR_UNKNOWN) > + return cmd->err; > + > + return ret; > + } > + > + return 0; > +} > + > +static struct i2c_dev_desc * > +i3c_master_find_i2c_dev_by_addr(const struct i3c_master_controller > *master, > + u16 addr) > +{ > + struct i2c_dev_desc *dev; > + > + i3c_bus_for_each_i2cdev(master->bus, dev) { > + if (dev->boardinfo->base.addr == addr) > + return dev; > + } > + > + return NULL; > +} > + > +/** > + * i3c_master_get_free_addr() - get a free address on the bus > + * @master: I3C master object > + * @start_addr: where to start searching > + * > + * This function must be called with the bus lock held in write mode. > + * > + * Return: the first free address starting at @start_addr (included) or - > ENOMEM > + * if there's no more address available. > + */ > +int i3c_master_get_free_addr(struct i3c_master_controller *master, > + u8 start_addr) > +{ > + return i3c_bus_get_free_addr(master->bus, start_addr); > +} > +EXPORT_SYMBOL_GPL(i3c_master_get_free_addr); > + > +static void i3c_device_release(struct device *dev) > +{ > + struct i3c_device *i3cdev = dev_to_i3cdev(dev); > + > + WARN_ON(i3cdev->desc); > + > + of_node_put(i3cdev->dev.of_node); > + kfree(i3cdev); > +} > + > +static void i3c_master_free_i3c_dev(struct i3c_dev_desc *dev) > +{ > + kfree(dev); > +} > + > +static struct i3c_dev_desc * > +i3c_master_alloc_i3c_dev(struct i3c_master_controller *master, > + const struct i3c_device_info *info) > +{ > + struct i3c_dev_desc *dev; > + > + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > + if (!dev) > + return ERR_PTR(-ENOMEM); > + > + dev->common.master = master; > + dev->info = *info; > + mutex_init(&dev->ibi_lock); > + > + return dev; > +} > + > +static int i3c_master_rstdaa_locked(struct i3c_master_controller *master, > + u8 addr) > +{ > + struct i3c_ccc_cmd_dest dest = { }; > + struct i3c_ccc_cmd cmd = { }; > + enum i3c_addr_slot_status addrstat; > + > + if (!master) > + return -EINVAL; > + > + addrstat = i3c_bus_get_addr_slot_status(master->bus, addr); > + if (addr != I3C_BROADCAST_ADDR && addrstat != > I3C_ADDR_SLOT_I3C_DEV) > + return -EINVAL; > + > + dest.addr = addr; > + cmd.dests = &dest; > + cmd.ndests = 1; > + cmd.rnw = false; > + cmd.id = I3C_CCC_RSTDAA(addr == I3C_BROADCAST_ADDR); > + > + return i3c_master_send_ccc_cmd_locked(master, &cmd); > +} > + > +/** > + * i3c_master_entdaa_locked() - start a DAA (Dynamic Address Assignment) > + * procedure > + * @master: master used to send frames on the bus > + * > + * Send a ENTDAA CCC command to start a DAA procedure. > + * > + * Note that this function only sends the ENTDAA CCC command, all the > logic > + * behind dynamic address assignment has to be handled in the I3C master > + * driver. > + * > + * This function must be called with the bus lock held in write mode. > + * > + * Return: 0 in case of success, a positive I3C error code if the error is > + * one of the official Mx error codes, and a negative error code otherwise. > + */ > +int i3c_master_entdaa_locked(struct i3c_master_controller *master) > +{ > + struct i3c_ccc_cmd_dest dest = { }; > + struct i3c_ccc_cmd cmd = { }; > + > + dest.addr = I3C_BROADCAST_ADDR; > + cmd.dests = &dest; > + cmd.ndests = 1; > + cmd.rnw = false; > + cmd.id = I3C_CCC_ENTDAA; > + > + return i3c_master_send_ccc_cmd_locked(master, &cmd); > +} > +EXPORT_SYMBOL_GPL(i3c_master_entdaa_locked); > + > +/** > + * i3c_master_disec_locked() - send a DISEC CCC command > + * @master: master used to send frames on the bus > + * @addr: a valid I3C slave address or %I3C_BROADCAST_ADDR > + * @evts: events to disable > + * > + * Send a DISEC CCC command to disable some or all events coming from a > + * specific slave, or all devices if @addr is %I3C_BROADCAST_ADDR. > + * > + * This function must be called with the bus lock held in write mode. > + * > + * Return: 0 in case of success, a positive I3C error code if the error is > + * one of the official Mx error codes, and a negative error code otherwise. > + */ > +int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr, > + u8 evts) > +{ > + struct i3c_ccc_events events = { > + .events = evts, > + }; > + struct i3c_ccc_cmd_dest dest = { > + .addr = addr, > + .payload.len = sizeof(events), > + .payload.data = &events, > + }; > + struct i3c_ccc_cmd cmd = { > + .id = I3C_CCC_DISEC(addr == I3C_BROADCAST_ADDR), > + .dests = &dest, > + .ndests = 1, > + }; > + > + return i3c_master_send_ccc_cmd_locked(master, &cmd); > +} > +EXPORT_SYMBOL_GPL(i3c_master_disec_locked); > + > +/** > + * i3c_master_enec_locked() - send an ENEC CCC command > + * @master: master used to send frames on the bus > + * @addr: a valid I3C slave address or %I3C_BROADCAST_ADDR > + * @evts: events to disable > + * > + * Sends an ENEC CCC command to enable some or all events coming from a > + * specific slave, or all devices if @addr is %I3C_BROADCAST_ADDR. > + * > + * This function must be called with the bus lock held in write mode. > + * > + * Return: 0 in case of success, a positive I3C error code if the error is > + * one of the official Mx error codes, and a negative error code otherwise. > + */ > +int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr, > + u8 evts) > +{ > + struct i3c_ccc_events events = { > + .events = evts, > + }; > + struct i3c_ccc_cmd_dest dest = { > + .addr = addr, > + .payload.len = sizeof(events), > + .payload.data = &events, > + }; > + struct i3c_ccc_cmd cmd = { > + .id = I3C_CCC_ENEC(addr == I3C_BROADCAST_ADDR), > + .dests = &dest, > + .ndests = 1, > + }; > + > + return i3c_master_send_ccc_cmd_locked(master, &cmd); > +} > +EXPORT_SYMBOL_GPL(i3c_master_enec_locked); > + > +/** > + * i3c_master_defslvs_locked() - send a DEFSLVS CCC command > + * @master: master used to send frames on the bus > + * > + * Send a DEFSLVS CCC command containing all the devices known to the > @master. > + * This is useful when you have secondary masters on the bus to propagate > + * device information. > + * > + * This should be called after all I3C devices have been discovered (in other > + * words, after the DAA procedure has finished) and instantiated in > + * &i3c_master_controller_ops->bus_init(). > + * It should also be called if a master ACKed an Hot-Join request and > assigned > + * a dynamic address to the device joining the bus. > + * > + * This function must be called with the bus lock held in write mode. > + * > + * Return: 0 in case of success, a positive I3C error code if the error is > + * one of the official Mx error codes, and a negative error code otherwise. > + */ > +int i3c_master_defslvs_locked(struct i3c_master_controller *master) > +{ > + struct i3c_ccc_cmd_dest dest = { > + .addr = I3C_BROADCAST_ADDR, > + }; > + struct i3c_ccc_cmd cmd = { > + .id = I3C_CCC_DEFSLVS, > + .dests = &dest, > + .ndests = 1, > + }; > + struct i3c_ccc_defslvs *defslvs; > + struct i3c_ccc_dev_desc *desc; > + struct i3c_dev_desc *i3cdev; > + struct i2c_dev_desc *i2cdev; > + struct i3c_bus *bus; > + bool send = false; > + int ndevs = 0, ret; > + > + if (!master) > + return -EINVAL; > + > + bus = i3c_master_get_bus(master); > + i3c_bus_for_each_i3cdev(bus, i3cdev) { > + ndevs++; > + > + if (i3cdev == master->this) > + continue; > + > + if (I3C_BCR_DEVICE_ROLE(i3cdev->info.bcr) == > + I3C_BCR_I3C_MASTER) > + send = true; > + } > + > + /* No other master on the bus, skip DEFSLVS. */ > + if (!send) > + return 0; > + > + i3c_bus_for_each_i2cdev(bus, i2cdev) > + ndevs++; > + > + dest.payload.len = sizeof(*defslvs) + > + ((ndevs - 1) * sizeof(struct i3c_ccc_dev_desc)); > + defslvs = kzalloc(dest.payload.len, GFP_KERNEL); > + if (!defslvs) > + return -ENOMEM; > + > + dest.payload.data = defslvs; > + > + defslvs->count = ndevs; > + defslvs->master.bcr = master->this->info.bcr; > + defslvs->master.dcr = master->this->info.dcr; > + defslvs->master.dyn_addr = master->this->info.dyn_addr << 1; > + defslvs->master.static_addr = I3C_BROADCAST_ADDR << 1; > + > + desc = defslvs->slaves; > + i3c_bus_for_each_i2cdev(bus, i2cdev) { > + desc->lvr = i2cdev->boardinfo->lvr; > + desc->static_addr = i2cdev->boardinfo->base.addr << 1; > + desc++; > + } > + > + i3c_bus_for_each_i3cdev(bus, i3cdev) { > + /* Skip the I3C dev representing this master. */ > + if (i3cdev == master->this) > + continue; > + > + desc->bcr = i3cdev->info.bcr; > + desc->dcr = i3cdev->info.dcr; > + desc->dyn_addr = i3cdev->info.dyn_addr << 1; > + desc->static_addr = i3cdev->info.static_addr << 1; > + desc++; > + } > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + kfree(defslvs); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(i3c_master_defslvs_locked); > + > +static int i3c_master_setdasa_locked(struct i3c_master_controller *master, > + u8 static_addr, u8 dyn_addr) > +{ > + struct i3c_ccc_setda setda = { > + .addr = dyn_addr << 1, > + }; > + struct i3c_ccc_cmd_dest dest = { > + .addr = static_addr, > + .payload.len = sizeof(setda), > + .payload.data = &setda, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = false, > + .id = I3C_CCC_SETDASA, > + .dests = &dest, > + .ndests = 1, > + }; > + > + if (!dyn_addr || !static_addr) > + return -EINVAL; > + > + return i3c_master_send_ccc_cmd_locked(master, &cmd); > +} > + > +static int i3c_master_setnewda_locked(struct i3c_master_controller > *master, > + u8 oldaddr, u8 newaddr) > +{ > + struct i3c_ccc_setda setda = { > + .addr = newaddr << 1, > + }; > + struct i3c_ccc_cmd_dest dest = { > + .addr = oldaddr, > + .payload.len = sizeof(setda), > + .payload.data = &setda, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = false, > + .id = I3C_CCC_SETNEWDA, > + .dests = &dest, > + .ndests = 1, > + }; > + > + if (!oldaddr || !newaddr) > + return -EINVAL; > + > + return i3c_master_send_ccc_cmd_locked(master, &cmd); > +} > + > +static int i3c_master_getmrl_locked(struct i3c_master_controller *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_mrl mrl; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(mrl), > + .payload.data = &mrl, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETMRL, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret; > + > + /* > + * When the device does not have IBI payload GETMRL only returns 2 > + * bytes of data. > + */ > + if (!(info->bcr & I3C_BCR_IBI_PAYLOAD)) > + dest.payload.len -= 1; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + if (dest.payload.len != sizeof(mrl)) > + return -EIO; > + > + info->max_read_len = be16_to_cpu(mrl.read_len); > + > + if (info->bcr & I3C_BCR_IBI_PAYLOAD) > + info->max_ibi_len = mrl.ibi_len; > + > + return 0; > +} > + > +static int i3c_master_getmwl_locked(struct i3c_master_controller *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_mwl mwl; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(mwl), > + .payload.data = &mwl, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETMWL, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + if (dest.payload.len != sizeof(mwl)) > + return -EIO; > + > + info->max_write_len = be16_to_cpu(mwl.len); > + > + return 0; > +} > + > +static int i3c_master_getmxds_locked(struct i3c_master_controller > *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_getmxds getmaxds; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(getmaxds), > + .payload.data = &getmaxds, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETMXDS, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + if (dest.payload.len != 2 && dest.payload.len != 5) > + return -EIO; > + > + info->max_read_ds = getmaxds.maxrd; > + info->max_read_ds = getmaxds.maxwr; > + if (dest.payload.len == 5) > + info->max_read_turnaround = getmaxds.maxrdturn[0] | > + ((u32)getmaxds.maxrdturn[1] << 8) > | > + ((u32)getmaxds.maxrdturn[2] << > 16); > + > + return 0; > +} > + > +static int i3c_master_gethdrcap_locked(struct i3c_master_controller > *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_gethdrcap gethdrcap; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(gethdrcap), > + .payload.data = &gethdrcap, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETHDRCAP, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + if (dest.payload.len != 1) > + return -EIO; > + > + info->hdr_cap = gethdrcap.modes; > + > + return 0; > +} > + > +static int i3c_master_getpid_locked(struct i3c_master_controller *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_getpid getpid; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(struct i3c_ccc_getpid), > + .payload.data = &getpid, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETPID, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret, i; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + info->pid = 0; > + for (i = 0; i < sizeof(getpid.pid); i++) { > + int sft = (sizeof(getpid.pid) - i - 1) * 8; > + > + info->pid |= (u64)getpid.pid[i] << sft; > + } > + > + return 0; > +} > + > +static int i3c_master_getbcr_locked(struct i3c_master_controller *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_getbcr getbcr; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(struct i3c_ccc_getbcr), > + .payload.data = &getbcr, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETBCR, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + info->bcr = getbcr.bcr; > + > + return 0; > +} > + > +static int i3c_master_getdcr_locked(struct i3c_master_controller *master, > + struct i3c_device_info *info) > +{ > + struct i3c_ccc_getdcr getdcr; > + struct i3c_ccc_cmd_dest dest = { > + .addr = info->dyn_addr, > + .payload.len = sizeof(struct i3c_ccc_getdcr), > + .payload.data = &getdcr, > + }; > + struct i3c_ccc_cmd cmd = { > + .rnw = true, > + .id = I3C_CCC_GETDCR, > + .dests = &dest, > + .ndests = 1, > + }; > + int ret; > + > + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); > + if (ret) > + return ret; > + > + info->dcr = getdcr.dcr; > + > + return 0; > +} > + > +static int i3c_master_retrieve_dev_info(struct i3c_dev_desc *dev) > +{ > + struct i3c_master_controller *master = i3c_dev_get_master(dev); > + enum i3c_addr_slot_status slot_status; > + int ret; > + > + if (!dev->info.dyn_addr) > + return -EINVAL; > + > + slot_status = i3c_bus_get_addr_slot_status(master->bus, > + dev->info.dyn_addr); > + if (slot_status == I3C_ADDR_SLOT_RSVD || > + slot_status == I3C_ADDR_SLOT_I2C_DEV) > + return -EINVAL; > + > + ret = i3c_master_getpid_locked(master, &dev->info); > + if (ret) > + return ret; > + > + ret = i3c_master_getbcr_locked(master, &dev->info); > + if (ret) > + return ret; > + > + ret = i3c_master_getdcr_locked(master, &dev->info); > + if (ret) > + return ret; > + > + if (dev->info.bcr & I3C_BCR_MAX_DATA_SPEED_LIM) { > + ret = i3c_master_getmxds_locked(master, &dev->info); > + if (ret) > + return ret; > + } > + > + if (dev->info.bcr & I3C_BCR_IBI_PAYLOAD) > + dev->info.max_ibi_len = 1; > + > + i3c_master_getmrl_locked(master, &dev->info); > + i3c_master_getmwl_locked(master, &dev->info); > + > + if (dev->info.bcr & I3C_BCR_HDR_CAP) { > + ret = i3c_master_gethdrcap_locked(master, &dev->info); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static void i3c_master_put_i3c_addrs(struct i3c_dev_desc *dev) > +{ > + struct i3c_master_controller *master = i3c_dev_get_master(dev); > + > + if (dev->info.static_addr) > + i3c_bus_set_addr_slot_status(master->bus, > + dev->info.static_addr, > + I3C_ADDR_SLOT_FREE); > + > + if (dev->info.dyn_addr) > + i3c_bus_set_addr_slot_status(master->bus, dev- > >info.dyn_addr, > + I3C_ADDR_SLOT_FREE); > + > + if (dev->boardinfo && dev->boardinfo->init_dyn_addr) > + i3c_bus_set_addr_slot_status(master->bus, dev- > >info.dyn_addr, > + I3C_ADDR_SLOT_FREE); > +} > + > +static int i3c_master_get_i3c_addrs(struct i3c_dev_desc *dev) > +{ > + struct i3c_master_controller *master = i3c_dev_get_master(dev); > + enum i3c_addr_slot_status status; > + > + if (!dev->info.static_addr && !dev->info.dyn_addr) > + return 0; > + > + if (dev->info.static_addr) { > + status = i3c_bus_get_addr_slot_status(master->bus, > + dev->info.static_addr); > + if (status != I3C_ADDR_SLOT_FREE) > + return -EBUSY; > + > + i3c_bus_set_addr_slot_status(master->bus, > + dev->info.static_addr, > + I3C_ADDR_SLOT_I3C_DEV); > + } > + > + /* > + * ->init_dyn_addr should have been reserved before that, so, if > we're > + * trying to apply a pre-reserved dynamic address, we should not try > + * to reserve the address slot a second time. > + */ > + if (dev->info.dyn_addr && > + (!dev->boardinfo || > + dev->boardinfo->init_dyn_addr != dev->info.dyn_addr)) { > + status = i3c_bus_get_addr_slot_status(master->bus, > + dev->info.dyn_addr); > + if (status != I3C_ADDR_SLOT_FREE) > + goto err_release_static_addr; > + > + i3c_bus_set_addr_slot_status(master->bus, dev- > >info.dyn_addr, > + I3C_ADDR_SLOT_I3C_DEV); > + } > + > + return 0; > + > +err_release_static_addr: > + if (dev->info.static_addr) > + i3c_bus_set_addr_slot_status(master->bus, > + dev->info.static_addr, > + I3C_ADDR_SLOT_FREE); > + > + return -EBUSY; > +} > + > +static int i3c_master_attach_i3c_dev(struct i3c_master_controller *master, > + struct i3c_dev_desc *dev) > +{ > + int ret; > + > + /* > + * We don't attach devices to the controller until they are > + * addressable on the bus. > + */ > + if (!dev->info.static_addr && !dev->info.dyn_addr) > + return 0; > + > + ret = i3c_master_get_i3c_addrs(dev); > + if (ret) > + return ret; > + > + /* Do not attach the master device itself. */ > + if (master->this != dev && master->ops->attach_i3c_dev) { > + ret = master->ops->attach_i3c_dev(dev); > + if (ret) { > + i3c_master_put_i3c_addrs(dev); > + return ret; > + } > + } > + > + list_add_tail(&dev->common.node, &master->bus->devs.i3c); > + > + return 0; > +} > + > +static int i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev, > + u8 old_dyn_addr) > +{ > + struct i3c_master_controller *master = i3c_dev_get_master(dev); > + enum i3c_addr_slot_status status; > + int ret; > + > + if (dev->info.dyn_addr != old_dyn_addr) { > + status = i3c_bus_get_addr_slot_status(master->bus, > + dev->info.dyn_addr); > + if (status != I3C_ADDR_SLOT_FREE) > + return -EBUSY; > + i3c_bus_set_addr_slot_status(master->bus, > + dev->info.dyn_addr, > + I3C_ADDR_SLOT_I3C_DEV); > + } > + > + if (master->ops->reattach_i3c_dev) { > + ret = master->ops->reattach_i3c_dev(dev, old_dyn_addr); > + if (ret) { > + i3c_master_put_i3c_addrs(dev); > + return ret; > + } > + } > + > + return 0; > +} > + > +static void i3c_master_detach_i3c_dev(struct i3c_dev_desc *dev) > +{ > + struct i3c_master_controller *master = i3c_dev_get_master(dev); > + > + /* Do not detach the master device itself. */ > + if (master->this != dev && master->ops->detach_i3c_dev) > + master->ops->detach_i3c_dev(dev); > + > + i3c_master_put_i3c_addrs(dev); > + list_del(&dev->common.node); > +} > + > +static int i3c_master_attach_i2c_dev(struct i3c_master_controller *master, > + struct i2c_dev_desc *dev) > +{ > + int ret; > + > + if (master->ops->attach_i2c_dev) { > + ret = master->ops->attach_i2c_dev(dev); > + if (ret) > + return ret; > + } > + > + list_add_tail(&dev->common.node, &master->bus->devs.i2c); > + > + return 0; > +} > + > +static void i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev) > +{ > + struct i3c_master_controller *master = i2c_dev_get_master(dev); > + > + list_del(&dev->common.node); > + > + if (master->ops->detach_i2c_dev) > + master->ops->detach_i2c_dev(dev); > +} > + > +static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev) > +{ > + struct i3c_master_controller *master = i3c_dev_get_master(dev); > + struct i3c_device_info info; > + int ret; > + > + if (!dev->boardinfo || !dev->boardinfo->init_dyn_addr || > + !dev->boardinfo->static_addr) > + return; > + > + ret = i3c_master_setdasa_locked(master, dev->info.static_addr, > + dev->boardinfo->init_dyn_addr); > + if (ret) > + return; > + > + dev->info.dyn_addr = dev->boardinfo->init_dyn_addr; > + ret = i3c_master_reattach_i3c_dev(dev, 0); > + if (ret) > + return; > + > + ret = i3c_master_retrieve_dev_info(dev); > + if (ret) > + goto err_rstdaa; > + > + dev->info = info; > + > + return; > + > +err_rstdaa: > + i3c_master_rstdaa_locked(master, dev->boardinfo->init_dyn_addr); > +} > + > +static void > +i3c_master_register_new_i3c_devs(struct i3c_master_controller *master) > +{ > + struct i3c_dev_desc *desc; > + int ret; > + > + if (!master->init_done) > + return; > + > + i3c_bus_for_each_i3cdev(master->bus, desc) { > + if (desc->dev || !desc->info.dyn_addr) > + continue; > + > + desc->dev = kzalloc(sizeof(*desc->dev), GFP_KERNEL); > + if (!desc->dev) > + continue; > + > + desc->dev->bus = master->bus; > + desc->dev->desc = desc; > + desc->dev->dev.parent = &master->bus->dev; > + if (desc == master->this) > + desc->dev->dev.type = &i3c_master_type; > + else > + desc->dev->dev.type = &i3c_device_type; > + desc->dev->dev.bus = &i3c_bus_type; > + desc->dev->dev.release = i3c_device_release; > + dev_set_name(&desc->dev->dev, "%d-%llx", master->bus- > >id, > + desc->info.pid); > + > + if (desc->boardinfo) > + desc->dev->dev.of_node = desc->boardinfo- > >of_node; > + > + pr_info("%s:%i\n", __func__, __LINE__); > + if (ret) > + dev_err(master->parent, > + "Failed to add I3C device (err = %d)\n", ret); > + } > +} The compiler gives a warning that "ret" may be used uninitialized in the above function, which is true since "ret" is never assigned a value. Also, I wonder about the "pr_info" call here, should there be a more detailed message here about the device being registered, other than the file name and line number? Otherwise, I have gone through the code in the process of writing the first iteration of the Qualcomm I3C master driver, and overall the framework looks good. Will update with any additional feedback I have. -- Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
Hi Mike, On Fri, 3 Aug 2018 15:38:43 -0600 <mshettel@codeaurora.org> wrote: > > +static void > > +i3c_master_register_new_i3c_devs(struct i3c_master_controller *master) > > +{ > > + struct i3c_dev_desc *desc; > > + int ret; > > + > > + if (!master->init_done) > > + return; > > + > > + i3c_bus_for_each_i3cdev(master->bus, desc) { > > + if (desc->dev || !desc->info.dyn_addr) > > + continue; > > + > > + desc->dev = kzalloc(sizeof(*desc->dev), GFP_KERNEL); > > + if (!desc->dev) > > + continue; > > + > > + desc->dev->bus = master->bus; > > + desc->dev->desc = desc; > > + desc->dev->dev.parent = &master->bus->dev; > > + if (desc == master->this) > > + desc->dev->dev.type = &i3c_master_type; > > + else > > + desc->dev->dev.type = &i3c_device_type; > > + desc->dev->dev.bus = &i3c_bus_type; > > + desc->dev->dev.release = i3c_device_release; > > + dev_set_name(&desc->dev->dev, "%d-%llx", master->bus- > > >id, > > + desc->info.pid); > > + > > + if (desc->boardinfo) > > + desc->dev->dev.of_node = desc->boardinfo- > > >of_node; > > + > > + pr_info("%s:%i\n", __func__, __LINE__); > > + if (ret) > > + dev_err(master->parent, > > + "Failed to add I3C device (err = %d)\n", > ret); > > + } > > +} > > The compiler gives a warning that "ret" may be used uninitialized in the > above function, which is true since "ret" is never assigned a value. Also, > I wonder about the "pr_info" call here, should there be a more detailed > message here about the device being registered, other than the file name and > line number? Yes, kbuild already reported that problem. I messed up when selecting the lines to add to my commit and added this trace instead of ret = device_register(&desc->dev->dev); Will be fixed in v7. > > Otherwise, I have gone through the code in the process of writing the first > iteration of the Qualcomm I3C master driver, and overall the framework looks > good. Will update with any additional feedback I have. Thanks for looking at the framework code. Your driver is in my TODO list. Regards, Boris
Hi Boris, On 19-07-2018 16:29, Boris Brezillon wrote: > +int i3c_bus_register(struct i3c_bus *i3cbus) > +{ > + struct i2c_dev_desc *desc; > + > + i3c_bus_for_each_i2cdev(i3cbus, desc) { > + switch (desc->boardinfo->lvr & I3C_LVR_I2C_INDEX_MASK) { > + case I3C_LVR_I2C_INDEX(0): > + if (i3cbus->mode < I3C_BUS_MODE_MIXED_FAST) > + i3cbus->mode = I3C_BUS_MODE_MIXED_FAST; > + break; > + > + case I3C_LVR_I2C_INDEX(1): > + case I3C_LVR_I2C_INDEX(2): > + if (i3cbus->mode < I3C_BUS_MODE_MIXED_SLOW) > + i3cbus->mode = I3C_BUS_MODE_MIXED_SLOW; > + break; > + > + default: > + return -EINVAL; > + } > + } > + > + if (!i3cbus->scl_rate.i3c) > + i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; > + > + if (!i3cbus->scl_rate.i2c) { > + if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW) > + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; > + else > + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE; > + } > + > + /* > + * I3C/I2C frequency may have been overridden, check that user-provided > + * values are not exceeding max possible frequency. > + */ > + if (i3cbus->scl_rate.i3c > I3C_BUS_MAX_I3C_SCL_RATE || > + i3cbus->scl_rate.i2c > I3C_BUS_I2C_FM_PLUS_SCL_RATE) { > + return -EINVAL; > + } > + > + dev_set_name(&i3cbus->dev, "i3c-%d", i3cbus->id); > + > + return device_add(&i3cbus->dev); > +} During the tests of the bus with i2c devices I found the i2c_dev_desc objects aren't allocated before this function. This cause i3cbus->mode = I3C_BUS_MODE_PURE. I want to do something for the slave and secondary master, do you already have infrastructure that you can share? Best regards, Vitor Soares
Hi Vitor, On Wed, 22 Aug 2018 17:43:34 +0100 vitor <Vitor.Soares@synopsys.com> wrote: > Hi Boris, > > > On 19-07-2018 16:29, Boris Brezillon wrote: > > +int i3c_bus_register(struct i3c_bus *i3cbus) > > +{ > > + struct i2c_dev_desc *desc; > > + > > + i3c_bus_for_each_i2cdev(i3cbus, desc) { > > + switch (desc->boardinfo->lvr & I3C_LVR_I2C_INDEX_MASK) { > > + case I3C_LVR_I2C_INDEX(0): > > + if (i3cbus->mode < I3C_BUS_MODE_MIXED_FAST) > > + i3cbus->mode = I3C_BUS_MODE_MIXED_FAST; > > + break; > > + > > + case I3C_LVR_I2C_INDEX(1): > > + case I3C_LVR_I2C_INDEX(2): > > + if (i3cbus->mode < I3C_BUS_MODE_MIXED_SLOW) > > + i3cbus->mode = I3C_BUS_MODE_MIXED_SLOW; > > + break; > > + > > + default: > > + return -EINVAL; > > + } > > + } > > + > > + if (!i3cbus->scl_rate.i3c) > > + i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; > > + > > + if (!i3cbus->scl_rate.i2c) { > > + if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW) > > + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; > > + else > > + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE; > > + } > > + > > + /* > > + * I3C/I2C frequency may have been overridden, check that user-provided > > + * values are not exceeding max possible frequency. > > + */ > > + if (i3cbus->scl_rate.i3c > I3C_BUS_MAX_I3C_SCL_RATE || > > + i3cbus->scl_rate.i2c > I3C_BUS_I2C_FM_PLUS_SCL_RATE) { > > + return -EINVAL; > > + } > > + > > + dev_set_name(&i3cbus->dev, "i3c-%d", i3cbus->id); > > + > > + return device_add(&i3cbus->dev); > > +} > During the tests of the bus with i2c devices I found the i2c_dev_desc > objects aren't allocated before this function. This cause i3cbus->mode = > I3C_BUS_MODE_PURE. I just checked and DT parsing (+ I2C descs creation) is done before i3c_bus_register() is called, so we should be good. How did you declare your I2C devices (right now, only DT declaration is supported). > > I want to do something for the slave and secondary master, do you > already have infrastructure that you can share? What do you mean? Regards, Boris
Hi Boris, On 24-08-2018 13:39, Boris Brezillon wrote: > Hi Vitor, > > On Wed, 22 Aug 2018 17:43:34 +0100 > vitor <Vitor.Soares@synopsys.com> wrote: > >> Hi Boris, >> >> >> On 19-07-2018 16:29, Boris Brezillon wrote: >>> +int i3c_bus_register(struct i3c_bus *i3cbus) >>> +{ >>> + struct i2c_dev_desc *desc; >>> + >>> + i3c_bus_for_each_i2cdev(i3cbus, desc) { >>> + switch (desc->boardinfo->lvr & I3C_LVR_I2C_INDEX_MASK) { >>> + case I3C_LVR_I2C_INDEX(0): >>> + if (i3cbus->mode < I3C_BUS_MODE_MIXED_FAST) >>> + i3cbus->mode = I3C_BUS_MODE_MIXED_FAST; >>> + break; >>> + >>> + case I3C_LVR_I2C_INDEX(1): >>> + case I3C_LVR_I2C_INDEX(2): >>> + if (i3cbus->mode < I3C_BUS_MODE_MIXED_SLOW) >>> + i3cbus->mode = I3C_BUS_MODE_MIXED_SLOW; >>> + break; >>> + >>> + default: >>> + return -EINVAL; >>> + } >>> + } >>> + >>> + if (!i3cbus->scl_rate.i3c) >>> + i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; >>> + >>> + if (!i3cbus->scl_rate.i2c) { >>> + if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW) >>> + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; >>> + else >>> + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE; >>> + } >>> + >>> + /* >>> + * I3C/I2C frequency may have been overridden, check that user-provided >>> + * values are not exceeding max possible frequency. >>> + */ >>> + if (i3cbus->scl_rate.i3c > I3C_BUS_MAX_I3C_SCL_RATE || >>> + i3cbus->scl_rate.i2c > I3C_BUS_I2C_FM_PLUS_SCL_RATE) { >>> + return -EINVAL; >>> + } >>> + >>> + dev_set_name(&i3cbus->dev, "i3c-%d", i3cbus->id); >>> + >>> + return device_add(&i3cbus->dev); >>> +} >> During the tests of the bus with i2c devices I found the i2c_dev_desc >> objects aren't allocated before this function. This cause i3cbus->mode = >> I3C_BUS_MODE_PURE. > I just checked and DT parsing (+ I2C descs creation) is done before > i3c_bus_register() is called, so we should be good. How did you declare > your I2C devices (right now, only DT declaration is supported). During the DT parsing, you create the i2c_dev_boardinfo. the i2c_dev_desc is created in i3c_master_bus_init() which is after the i3c_mater_create_bus(). One possible way to fix this is to pass master also to i3c_bus_register and iterate over i2c_dev_board_info list. >> I want to do something for the slave and secondary master, do you >> already have infrastructure that you can share? > What do you mean? > > Regards, > > Boris I want start to add the secondary master functionality but it is also necessary to add the infrastructure to the subsystem. So, to avoid duplicated work can you share your plans for the secondary master? Best regards, Vitor Soares
Hi Vitor, On Fri, 24 Aug 2018 18:52:52 +0100 vitor <Vitor.Soares@synopsys.com> wrote: > Hi Boris, > > > On 24-08-2018 13:39, Boris Brezillon wrote: > > Hi Vitor, > > > > On Wed, 22 Aug 2018 17:43:34 +0100 > > vitor <Vitor.Soares@synopsys.com> wrote: > > > >> Hi Boris, > >> > >> > >> On 19-07-2018 16:29, Boris Brezillon wrote: > >>> +int i3c_bus_register(struct i3c_bus *i3cbus) > >>> +{ > >>> + struct i2c_dev_desc *desc; > >>> + > >>> + i3c_bus_for_each_i2cdev(i3cbus, desc) { > >>> + switch (desc->boardinfo->lvr & I3C_LVR_I2C_INDEX_MASK) { > >>> + case I3C_LVR_I2C_INDEX(0): > >>> + if (i3cbus->mode < I3C_BUS_MODE_MIXED_FAST) > >>> + i3cbus->mode = I3C_BUS_MODE_MIXED_FAST; > >>> + break; > >>> + > >>> + case I3C_LVR_I2C_INDEX(1): > >>> + case I3C_LVR_I2C_INDEX(2): > >>> + if (i3cbus->mode < I3C_BUS_MODE_MIXED_SLOW) > >>> + i3cbus->mode = I3C_BUS_MODE_MIXED_SLOW; > >>> + break; > >>> + > >>> + default: > >>> + return -EINVAL; > >>> + } > >>> + } > >>> + > >>> + if (!i3cbus->scl_rate.i3c) > >>> + i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; > >>> + > >>> + if (!i3cbus->scl_rate.i2c) { > >>> + if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW) > >>> + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; > >>> + else > >>> + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE; > >>> + } > >>> + > >>> + /* > >>> + * I3C/I2C frequency may have been overridden, check that user-provided > >>> + * values are not exceeding max possible frequency. > >>> + */ > >>> + if (i3cbus->scl_rate.i3c > I3C_BUS_MAX_I3C_SCL_RATE || > >>> + i3cbus->scl_rate.i2c > I3C_BUS_I2C_FM_PLUS_SCL_RATE) { > >>> + return -EINVAL; > >>> + } > >>> + > >>> + dev_set_name(&i3cbus->dev, "i3c-%d", i3cbus->id); > >>> + > >>> + return device_add(&i3cbus->dev); > >>> +} > >> During the tests of the bus with i2c devices I found the i2c_dev_desc > >> objects aren't allocated before this function. This cause i3cbus->mode = > >> I3C_BUS_MODE_PURE. > > I just checked and DT parsing (+ I2C descs creation) is done before > > i3c_bus_register() is called, so we should be good. How did you declare > > your I2C devices (right now, only DT declaration is supported). > During the DT parsing, you create the i2c_dev_boardinfo. the > i2c_dev_desc is created in i3c_master_bus_init() which is after the > i3c_mater_create_bus(). Oops, you're right. > One possible way to fix this is to pass master > also to i3c_bus_register and iterate over i2c_dev_board_info list. Yes, that's the proper fix. I'll do that in v7. > > >> I want to do something for the slave and secondary master, do you > >> already have infrastructure that you can share? > > What do you mean? > > > > Regards, > > > > Boris > > I want start to add the secondary master functionality but it is also > necessary to add the infrastructure to the subsystem. > So, to avoid duplicated work can you share your plans for the secondary > master? Well, before even considering supporting secondary master registration, we need to handle mastership handover. As for the DAA operation, it's likely to be host specific, so we'll have to add a new hook to the i3c_master_controller_ops struct. Once you've done that, we'll have trigger a mastership handover everytime an I3C driver tries to send a frame on the bus, and the master this frame should do through is not in control of the bus. That should be pretty easy for the nominal case, but error cases are likely to be hard to deal with. Note that I have a ->cur_master field in the i3c_bus object which stores allows us to track whose the currently active master. If master->this != master->bus->cur_master that means you need to start a mastership handover procedure. That's all I thought about for now, and we'll probably face other problems when implementing it. Let me know if you have other questions, and don't hesitate to share your code early during the development phase. Also note that the bus representation is likely to change based on Arnd's feedback, so you might have to rework your implementation a bit at some point. Regards, Boris
Hi Boris, The DT Bindings say "The node describing an I3C bus should be named i3c-master.". Do you have a field for secondary master? On 24-08-2018 19:16, Boris Brezillon wrote: > Well, before even considering supporting secondary master registration, > we need to handle mastership handover. As for the DAA operation, it's > likely to be host specific, so we'll have to add a new hook to the > i3c_master_controller_ops struct. Do you mean when master try to delegate the bus ownership through GETACCMST? or to get the bus ownership with IBI-MR? I think that could be useful to pass the ibi type on request_ibi(), there is some case where the master doesn't support IBI-MR. > Once you've done that, we'll have trigger a mastership handover > everytime an I3C driver tries to send a frame on the bus, and the > master this frame should do through is not in control of the bus. That > should be pretty easy for the nominal case, but error cases are likely > to be hard to deal with. > Note that I have a ->cur_master field in the i3c_bus object which > stores allows us to track whose the currently active master. If > master->this != master->bus->cur_master that means you need to start a > mastership handover procedure. > > That's all I thought about for now, and we'll probably face other > problems when implementing it. Let me know if you have other questions, > and don't hesitate to share your code early during the development > phase. > > Also note that the bus representation is likely to change based on > Arnd's feedback, so you might have to rework your implementation a bit > at some point. > > Regards, > > Boris Best regards, Vitor Soares
Hi Vitor, On Tue, 28 Aug 2018 12:50:12 +0100 vitor <Vitor.Soares@synopsys.com> wrote: > Hi Boris, > > The DT Bindings say "The node describing an I3C bus should be named > i3c-master.". Do you have a field for secondary master? > > On 24-08-2018 19:16, Boris Brezillon wrote: > > Well, before even considering supporting secondary master registration, > > we need to handle mastership handover. As for the DAA operation, it's > > likely to be host specific, so we'll have to add a new hook to the > > i3c_master_controller_ops struct. > Do you mean when master try to delegate the bus ownership through > GETACCMST? or to get the bus ownership with IBI-MR? I think we need to support both. > > I think that could be useful to pass the ibi type on request_ibi(), > there is some case where the master doesn't support IBI-MR. Actually, I was planning on making it completely separate from regular slave IBIs. That is, the master controller driver would demux the slave, MR and Hot Join IBIs, and if there's an MR request, queue a mastership handover work to the workqueue (pretty much what we do for Hot-Join already). Mastership handover is anyway likely to be IP specific, so I don't think there's a need to make it look like a regular IBI. Regarding whether IBI-MR support should be exposed to the I3C framework or not depends on how much will be automated on the framework side. I don't the answer yet, but that's probably something will figure out along the road. Regards, Boris
Hi Vitor,
I have already implemented Mastership request/handover but we are waiting for Boris’s patch to be accepted and merged. Anyway, my comments below.
On 8/28/18, 2:02 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
EXTERNAL MAIL
Hi Vitor,
On Tue, 28 Aug 2018 12:50:12 +0100
vitor <Vitor.Soares@synopsys.com> wrote:
> Hi Boris,
>
> The DT Bindings say "The node describing an I3C bus should be named
> i3c-master.". Do you have a field for secondary master?
I think we don’t need separate field for secondary master. Main and secondary masters
support similar functionalities. It’s enough to have this state internally and do mastership it it's needed.
>
> On 24-08-2018 19:16, Boris Brezillon wrote:
> > Well, before even considering supporting secondary master registration,
> > we need to handle mastership handover. As for the DAA operation, it's
> > likely to be host specific, so we'll have to add a new hook to the
> > i3c_master_controller_ops struct.
> Do you mean when master try to delegate the bus ownership through
> GETACCMST? or to get the bus ownership with IBI-MR?
I think we need to support both.
I agree.
>
> I think that could be useful to pass the ibi type on request_ibi(),
> there is some case where the master doesn't support IBI-MR.
Actually, I was planning on making it completely separate from
regular slave IBIs. That is, the master controller driver would demux
the slave, MR and Hot Join IBIs, and if there's an MR request, queue a
mastership handover work to the workqueue (pretty much what we do for
Hot-Join already). Mastership handover is anyway likely to be IP
specific, so I don't think there's a need to make it look like a
regular IBI.
I think it's better to have separate function to do mastership request.
Regarding whether IBI-MR support should be exposed to the I3C framework
or not depends on how much will be automated on the framework side. I
don't the answer yet, but that's probably something will figure out
along the road.
My current implementation is: when request_mastership field
of i3c_master_controller_ops structure is set, master driver supports mastership requests.
That's how I check if this is supported or not.
Regards,
Boris
Regards,
Przemek
Hi Przemek, On Tue, 28 Aug 2018 12:55:20 +0000 Przemyslaw Gaj <pgaj@cadence.com> wrote: > Hi Vitor, > > I have already implemented Mastership request/handover but we are waiting for Boris’s patch to be accepted and merged. Anyway, my comments below. > > On 8/28/18, 2:02 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote: > > EXTERNAL MAIL > > > Hi Vitor, > > On Tue, 28 Aug 2018 12:50:12 +0100 > vitor <Vitor.Soares@synopsys.com> wrote: > > > Hi Boris, > > > > The DT Bindings say "The node describing an I3C bus should be named > > i3c-master.". Do you have a field for secondary master? > > I think we don’t need separate field for secondary master. Main and secondary masters > support similar functionalities. It’s enough to have this state internally and do mastership it it's needed. > > > > > On 24-08-2018 19:16, Boris Brezillon wrote: > > > Well, before even considering supporting secondary master registration, > > > we need to handle mastership handover. As for the DAA operation, it's > > > likely to be host specific, so we'll have to add a new hook to the > > > i3c_master_controller_ops struct. > > Do you mean when master try to delegate the bus ownership through > > GETACCMST? or to get the bus ownership with IBI-MR? > > I think we need to support both. > > I agree. > > > > > I think that could be useful to pass the ibi type on request_ibi(), > > there is some case where the master doesn't support IBI-MR. > > Actually, I was planning on making it completely separate from > regular slave IBIs. That is, the master controller driver would demux > the slave, MR and Hot Join IBIs, and if there's an MR request, queue a > mastership handover work to the workqueue (pretty much what we do for > Hot-Join already). Mastership handover is anyway likely to be IP > specific, so I don't think there's a need to make it look like a > regular IBI. > > I think it's better to have separate function to do mastership request. > > Regarding whether IBI-MR support should be exposed to the I3C framework > or not depends on how much will be automated on the framework side. I > don't the answer yet, but that's probably something will figure out > along the road. > > My current implementation is: when request_mastership field > of i3c_master_controller_ops structure is set, master driver supports mastership requests. > That's how I check if this is supported or not. Can you maybe host your code on a public repo (I can push it for you if needed) so that you and Vitor can start discussing implementation details. Thanks, Boris
On Tue, 28 Aug 2018 12:55:20 +0000 Przemyslaw Gaj <pgaj@cadence.com> wrote: > Hi Vitor, > > I have already implemented Mastership request/handover but we are > waiting for Boris’s patch to be accepted and merged. My bad. I didn't have time to work on the bus/master rework suggested by Arnd before going on vacation. I hope I'll be able to work on that soon.
Hi Boris,
On 8/28/18, 3:01 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
EXTERNAL MAIL
Hi Przemek,
On Tue, 28 Aug 2018 12:55:20 +0000
Przemyslaw Gaj <pgaj@cadence.com> wrote:
> Hi Vitor,
>
> I have already implemented Mastership request/handover but we are waiting for Boris’s patch to be accepted and merged. Anyway, my comments below.
>
> On 8/28/18, 2:02 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
>
> EXTERNAL MAIL
>
>
> Hi Vitor,
>
> On Tue, 28 Aug 2018 12:50:12 +0100
> vitor <Vitor.Soares@synopsys.com> wrote:
>
> > Hi Boris,
> >
> > The DT Bindings say "The node describing an I3C bus should be named
> > i3c-master.". Do you have a field for secondary master?
>
> I think we don’t need separate field for secondary master. Main and secondary masters
> support similar functionalities. It’s enough to have this state internally and do mastership it it's needed.
>
> >
> > On 24-08-2018 19:16, Boris Brezillon wrote:
> > > Well, before even considering supporting secondary master registration,
> > > we need to handle mastership handover. As for the DAA operation, it's
> > > likely to be host specific, so we'll have to add a new hook to the
> > > i3c_master_controller_ops struct.
> > Do you mean when master try to delegate the bus ownership through
> > GETACCMST? or to get the bus ownership with IBI-MR?
>
> I think we need to support both.
>
> I agree.
>
> >
> > I think that could be useful to pass the ibi type on request_ibi(),
> > there is some case where the master doesn't support IBI-MR.
>
> Actually, I was planning on making it completely separate from
> regular slave IBIs. That is, the master controller driver would demux
> the slave, MR and Hot Join IBIs, and if there's an MR request, queue a
> mastership handover work to the workqueue (pretty much what we do for
> Hot-Join already). Mastership handover is anyway likely to be IP
> specific, so I don't think there's a need to make it look like a
> regular IBI.
>
> I think it's better to have separate function to do mastership request.
>
> Regarding whether IBI-MR support should be exposed to the I3C framework
> or not depends on how much will be automated on the framework side. I
> don't the answer yet, but that's probably something will figure out
> along the road.
>
> My current implementation is: when request_mastership field
> of i3c_master_controller_ops structure is set, master driver supports mastership requests.
> That's how I check if this is supported or not.
Can you maybe host your code on a public repo (I can push it for you if
needed) so that you and Vitor can start discussing implementation
details.
Sure! Please give me some time. I'll try to do it this week or early next week.
Thanks,
Boris
Thanks,
Przemek
Hi Przemyslaw On 28-08-2018 13:55, Przemyslaw Gaj wrote: > Hi Vitor, > > I have already implemented Mastership request/handover but we are waiting for Boris’s patch to be accepted and merged. Anyway, my comments below. > > On 8/28/18, 2:02 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote: > > EXTERNAL MAIL > > > Hi Vitor, > > On Tue, 28 Aug 2018 12:50:12 +0100 > vitor <Vitor.Soares@synopsys.com> wrote: > > > Hi Boris, > > > > The DT Bindings say "The node describing an I3C bus should be named > > i3c-master.". Do you have a field for secondary master? > > I think we don’t need separate field for secondary master. Main and secondary masters > support similar functionalities. It’s enough to have this state internally and do mastership it it's needed. Yes, you are right. > > > > > On 24-08-2018 19:16, Boris Brezillon wrote: > > > Well, before even considering supporting secondary master registration, > > > we need to handle mastership handover. As for the DAA operation, it's > > > likely to be host specific, so we'll have to add a new hook to the > > > i3c_master_controller_ops struct. > > Do you mean when master try to delegate the bus ownership through > > GETACCMST? or to get the bus ownership with IBI-MR? > > I think we need to support both. > > I agree. That's ok to me. > > > > > I think that could be useful to pass the ibi type on request_ibi(), > > there is some case where the master doesn't support IBI-MR. > > Actually, I was planning on making it completely separate from > regular slave IBIs. That is, the master controller driver would demux > the slave, MR and Hot Join IBIs, and if there's an MR request, queue a > mastership handover work to the workqueue (pretty much what we do for > Hot-Join already). Mastership handover is anyway likely to be IP > specific, so I don't think there's a need to make it look like a > regular IBI. > > I think it's better to have separate function to do mastership request. > > Regarding whether IBI-MR support should be exposed to the I3C framework > or not depends on how much will be automated on the framework side. I > don't the answer yet, but that's probably something will figure out > along the road. > > My current implementation is: when request_mastership field > of i3c_master_controller_ops structure is set, master driver supports mastership requests. > That's how I check if this is supported or not. > > Regards, > > Boris > > Regards, > Przemek > when you say request_mastership, do you mean the current master do the mastership hand-off or the secondary master request to be current master? So, per my understanding since the Main master support the hand-off of the bus you accept all incoming MR, right? Or do you check all devices BCR? Best regards, Vitor Soares
Hi Vitor,
On 8/30/18, 3:57 PM, "vitor" <Vitor.Soares@synopsys.com> wrote:
EXTERNAL MAIL
Hi Przemyslaw
Just Przemek :)
On 28-08-2018 13:55, Przemyslaw Gaj wrote:
> Hi Vitor,
>
> I have already implemented Mastership request/handover but we are waiting for Boris’s patch to be accepted and merged. Anyway, my comments below.
>
> On 8/28/18, 2:02 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
>
> EXTERNAL MAIL
>
>
> Hi Vitor,
>
> On Tue, 28 Aug 2018 12:50:12 +0100
> vitor <Vitor.Soares@synopsys.com> wrote:
>
> > Hi Boris,
> >
> > The DT Bindings say "The node describing an I3C bus should be named
> > i3c-master.". Do you have a field for secondary master?
>
> I think we don’t need separate field for secondary master. Main and secondary masters
> support similar functionalities. It’s enough to have this state internally and do mastership it it's needed.
Yes, you are right.
>
> >
> > On 24-08-2018 19:16, Boris Brezillon wrote:
> > > Well, before even considering supporting secondary master registration,
> > > we need to handle mastership handover. As for the DAA operation, it's
> > > likely to be host specific, so we'll have to add a new hook to the
> > > i3c_master_controller_ops struct.
> > Do you mean when master try to delegate the bus ownership through
> > GETACCMST? or to get the bus ownership with IBI-MR?
>
> I think we need to support both.
>
> I agree.
That's ok to me.
>
> >
> > I think that could be useful to pass the ibi type on request_ibi(),
> > there is some case where the master doesn't support IBI-MR.
>
> Actually, I was planning on making it completely separate from
> regular slave IBIs. That is, the master controller driver would demux
> the slave, MR and Hot Join IBIs, and if there's an MR request, queue a
> mastership handover work to the workqueue (pretty much what we do for
> Hot-Join already). Mastership handover is anyway likely to be IP
> specific, so I don't think there's a need to make it look like a
> regular IBI.
>
> I think it's better to have separate function to do mastership request.
>
> Regarding whether IBI-MR support should be exposed to the I3C framework
> or not depends on how much will be automated on the framework side. I
> don't the answer yet, but that's probably something will figure out
> along the road.
>
> My current implementation is: when request_mastership field
> of i3c_master_controller_ops structure is set, master driver supports mastership requests.
> That's how I check if this is supported or not.
>
> Regards,
>
> Boris
>
> Regards,
> Przemek
>
when you say request_mastership, do you mean the current master do the
mastership hand-off or the secondary master request to be current master?
I mean secondary master requests to be current master. Current master do the mastership
hand-off using GETACCMST command.
So, per my understanding since the Main master support the hand-off of
the bus you accept all incoming MR, right? Or do you check all devices BCR?
I'm not sure what do you mean here. Mastership request(MR) is from secondary master
to current master. Current master can NACK this request if for example it comes from
wrong device. If it's ok, current master sends GETACCMST command and secondary master
may ACK or NACK this command. It it's acked, secondary master becomes current master.
Best regards,
Vitor Soares
Please let me know if something is unclear.
Regards,
Przemek
Hi Przemek, On 30-08-2018 20:00, Przemyslaw Gaj wrote: > So, per my understanding since the Main master support the hand-off of > the bus you accept all incoming MR, right? Or do you check all devices BCR? > > I'm not sure what do you mean here. Mastership request(MR) is from secondary master > to current master. Current master can NACK this request if for example it comes from > wrong device. If it's ok, current master sends GETACCMST command and secondary master > may ACK or NACK this command. It it's acked, secondary master becomes current master. > > Best regards, > Vitor Soares > > Please let me know if something is unclear. > > Regards, > Przemek > Sorry, it s not clear yet. For instances there is a bus with several secondary master. If each of them request the bus mastership (one at a time), will you accept all by default? Because you can only accept only some of them. Regards, Vitor Soares
Hi Vitor,
On 9/3/18, 11:33 AM, "vitor" <Vitor.Soares@synopsys.com> wrote:
EXTERNAL MAIL
Hi Przemek,
On 30-08-2018 20:00, Przemyslaw Gaj wrote:
> So, per my understanding since the Main master support the hand-off of
> the bus you accept all incoming MR, right? Or do you check all devices BCR?
>
> I'm not sure what do you mean here. Mastership request(MR) is from secondary master
> to current master. Current master can NACK this request if for example it comes from
> wrong device. If it's ok, current master sends GETACCMST command and secondary master
> may ACK or NACK this command. It it's acked, secondary master becomes current master.
>
> Best regards,
> Vitor Soares
>
> Please let me know if something is unclear.
>
> Regards,
> Przemek
>
Sorry, it s not clear yet.
For instances there is a bus with several secondary master. If each of
them request the bus mastership (one at a time), will you accept all by
default? Because you can only accept only some of them.
First of all, only devices which have Mastership request event enabled (ENMR slave event)
can request mastership. Second thing is that this device needs to have IBI enabled in
current master. I accept all such devices. There is no additional logic for now, we can add it
in the future.
I was very busy recently. I'm almost ready to publish my changes related to mastership request.
I'm sorry for the delay.
Regards,
Vitor Soares
Regards,
Przemek
Hi Boris, Vitor,
This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature.
https://github.com/przemekgaj/i3c-linux/commit/d54fe68a9d3e573c0c454a2c6f1afafc20142ec5
Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters.
It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device.
I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :)
Thanks,
Przemek
On 9/3/18, 11:33 AM, "vitor" <Vitor.Soares@synopsys.com> wrote:
EXTERNAL MAIL
Hi Przemek,
On 30-08-2018 20:00, Przemyslaw Gaj wrote:
> So, per my understanding since the Main master support the hand-off of
> the bus you accept all incoming MR, right? Or do you check all devices BCR?
>
> I'm not sure what do you mean here. Mastership request(MR) is from secondary master
> to current master. Current master can NACK this request if for example it comes from
> wrong device. If it's ok, current master sends GETACCMST command and secondary master
> may ACK or NACK this command. It it's acked, secondary master becomes current master.
>
> Best regards,
> Vitor Soares
>
> Please let me know if something is unclear.
>
> Regards,
> Przemek
>
Sorry, it s not clear yet.
For instances there is a bus with several secondary master. If each of
them request the bus mastership (one at a time), will you accept all by
default? Because you can only accept only some of them.
Regards,
Vitor Soares
On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > > Hi Boris, Vitor, > > This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > https://github.com/przemekgaj/i3c-linux/commit/d54fe68a9d3e573c0c454a2c6f1afafc20142ec5 > > Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > > I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) Can you explain the reason for having a user space interface and DT property? I thought we had concluded earlier that we wouldn't need that, but it's possible that I missed something in the discussion since then. Arnd
On Thu, 6 Sep 2018 14:59:46 +0200 Arnd Bergmann <arnd@arndb.de> wrote: > On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > > > > Hi Boris, Vitor, > > > > This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > > https://github.com/przemekgaj/i3c-linux/commit/d54fe68a9d3e573c0c454a2c6f1afafc20142ec5 > > > > Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > > It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > > > > I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) > > > Can you explain the reason for having a user space interface and DT property? > I thought we had concluded earlier that we wouldn't need that, but it's possible > that I missed something in the discussion since then. I don't think the sysfs knob is needed, this being said, after thinking a bit more about mastership handover and the secondary master case, I think we have something important to solve. When a master is not in control of the bus, it gets informed of devices present on the bus by monitoring DAA or DEFSLVS broadcast events. That means the secondary master should populate the bus with I3C/I2C devices on such events, but that's not enough, because DEFSLVS/DAA do not provide all device info. Some of them (like read/write/ibi limitations) require extra CCC commands, and, to send those CCC commands, the secondary master must claim the bus. We could add a case where we declare devices as partially discovered until the master acquires ownership of the bus, but that means part of the data returned by i3c_device_get_info() will be inaccurate, which might have an impact on some i3c driver ->probe() functions. We could also say that partially discovered devices should not be registered to the device model, but we then hit the problem of "who can force the secondary master to claim the bus if there's no users?".
On Thu, 6 Sep 2018 15:14:37 +0200 Boris Brezillon <boris.brezillon@bootlin.com> wrote: > On Thu, 6 Sep 2018 14:59:46 +0200 > Arnd Bergmann <arnd@arndb.de> wrote: > > > On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > > > > > > Hi Boris, Vitor, > > > > > > This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > > > https://github.com/przemekgaj/i3c-linux/commit/d54fe68a9d3e573c0c454a2c6f1afafc20142ec5 > > > > > > Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > > > It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > > > > > > I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) > > > > > > Can you explain the reason for having a user space interface and DT property? > > I thought we had concluded earlier that we wouldn't need that, but it's possible > > that I missed something in the discussion since then. > > I don't think the sysfs knob is needed, this being said, after thinking > a bit more about mastership handover and the secondary master case, I > think we have something important to solve. > > When a master is not in control of the bus, it gets informed of devices > present on the bus by monitoring DAA or DEFSLVS broadcast events. That > means the secondary master should populate the bus with I3C/I2C devices > on such events, but that's not enough, because DEFSLVS/DAA do not > provide all device info. Some of them (like read/write/ibi limitations) > require extra CCC commands, and, to send those CCC commands, the > secondary master must claim the bus. We could add a case where we > declare devices as partially discovered until the master acquires > ownership of the bus, but that means part of the data returned by > i3c_device_get_info() will be inaccurate, which might have an impact on > some i3c driver ->probe() functions. Hm, one possible solution would be to register partially discovered devices to the device model and let i3c_device_get_info() claim the bus and request missing data when needed. This way, if the driver needs to call i3c_device_get_info() in its probe path, it should work just fine.
On Thu, Sep 6, 2018 at 3:21 PM Boris Brezillon <boris.brezillon@bootlin.com> wrote: > > On Thu, 6 Sep 2018 15:14:37 +0200 > Boris Brezillon <boris.brezillon@bootlin.com> wrote: > > When a master is not in control of the bus, it gets informed of devices > > present on the bus by monitoring DAA or DEFSLVS broadcast events. That > > means the secondary master should populate the bus with I3C/I2C devices > > on such events, but that's not enough, because DEFSLVS/DAA do not > > provide all device info. Some of them (like read/write/ibi limitations) > > require extra CCC commands, and, to send those CCC commands, the > > secondary master must claim the bus. We could add a case where we > > declare devices as partially discovered until the master acquires > > ownership of the bus, but that means part of the data returned by > > i3c_device_get_info() will be inaccurate, which might have an impact on > > some i3c driver ->probe() functions. > > Hm, one possible solution would be to register partially discovered > devices to the device model and let i3c_device_get_info() claim the bus > and request missing data when needed. This way, if the driver needs to > call i3c_device_get_info() in its probe path, it should work just fine. I guess you could also call i3c_device_get_info() in the common i3c_probe() function before calling into the driver. However, either way, we may still have a problem here: if the current master decides not to hand over master access to us at all, the probe() function will be blocked indefinitely, and that may stop us from probing other devices later on, or hang the module loader (depending on what context that probe() is called from). Using a timeout here could avoid the hang, but leads to other potential issues, e.g. how to decide whether to retry the probe later. Arnd
On 9/6/18, 3:14 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
EXTERNAL MAIL
On Thu, 6 Sep 2018 14:59:46 +0200
Arnd Bergmann <arnd@arndb.de> wrote:
> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote:
> >
> > Hi Boris, Vitor,
> >
> > This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature.
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=CMnAfM_OfpqcWZRfiqcRWw&m=OPSa25ENnrF0Qv70DG49ZngfdygJZubjo3TOgBA3pJ4&s=_C6i1KPplQGcWvQYPkrGx7V3TjKDJvqt3KG-vcdU2K4&e=
> >
> > Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters.
> > It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device.
> >
> > I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :)
>
>
> Can you explain the reason for having a user space interface and DT property?
> I thought we had concluded earlier that we wouldn't need that, but it's possible
> that I missed something in the discussion since then.
I don't think the sysfs knob is needed, this being said, after thinking
a bit more about mastership handover and the secondary master case, I
think we have something important to solve.
When a master is not in control of the bus, it gets informed of devices
present on the bus by monitoring DAA or DEFSLVS broadcast events. That
means the secondary master should populate the bus with I3C/I2C devices
on such events, but that's not enough, because DEFSLVS/DAA do not
provide all device info. Some of them (like read/write/ibi limitations)
require extra CCC commands, and, to send those CCC commands, the
secondary master must claim the bus. We could add a case where we
declare devices as partially discovered until the master acquires
ownership of the bus, but that means part of the data returned by
i3c_device_get_info() will be inaccurate, which might have an impact on
some i3c driver ->probe() functions.
How do you want to handle cases when secondary master joins the bus after
DEFSLVS? Of course we can send DEFSLVS after secondary master joins the bus.
We could also say that partially discovered devices should not be
registered to the device model, but we then hit the problem of "who can
force the secondary master to claim the bus if there's no users?".
Now I feel like I missed something. Do you want to populate second instance
of the same physical bus? If yes, then we don't need to have reference
between masters in DT.
Hi, On 06-09-2018 14:20, Boris Brezillon wrote: > On Thu, 6 Sep 2018 15:14:37 +0200 > Boris Brezillon <boris.brezillon@bootlin.com> wrote: > >> On Thu, 6 Sep 2018 14:59:46 +0200 >> Arnd Bergmann <arnd@arndb.de> wrote: >> >>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: >>>> Hi Boris, Vitor, >>>> >>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e= >>>> >>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. >>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. >>>> >>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) >>> >>> Can you explain the reason for having a user space interface and DT property? >>> I thought we had concluded earlier that we wouldn't need that, but it's possible >>> that I missed something in the discussion since then. >> I don't think the sysfs knob is needed, this being said, after thinking >> a bit more about mastership handover and the secondary master case, I >> think we have something important to solve. >> >> When a master is not in control of the bus, it gets informed of devices >> present on the bus by monitoring DAA or DEFSLVS broadcast events. That >> means the secondary master should populate the bus with I3C/I2C devices >> on such events, but that's not enough, because DEFSLVS/DAA do not >> provide all device info.Some of them (like read/write/ibi limitations) >> require extra CCC commands, and, to send those CCC commands, the >> secondary master must claim the bus. We could add a case where we >> declare devices as partially discovered until the master acquires >> ownership of the bus, but that means part of the data returned by >> i3c_device_get_info() will be inaccurate, which might have an impact on >> some i3c driver ->probe() functions. > Hm, one possible solution would be to register partially discovered > devices to the device model and let i3c_device_get_info() claim the bus > and request missing data when needed. This way, if the driver needs to > call i3c_device_get_info() in its probe path, it should work just fine. Why don't use the i3c_master_add_i3c_dev_locked that job? It create, attach and retrieve the device info. This can be triggered after the secondary master receive ENEC MR until them is keep in the driver memory. Best regards, Vitor Soares
On Thu, 6 Sep 2018 13:47:29 +0000 Przemyslaw Gaj <pgaj@cadence.com> wrote: > On 9/6/18, 3:14 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote: > > EXTERNAL MAIL > > > On Thu, 6 Sep 2018 14:59:46 +0200 > Arnd Bergmann <arnd@arndb.de> wrote: > > > On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > > > > > > Hi Boris, Vitor, > > > > > > This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=CMnAfM_OfpqcWZRfiqcRWw&m=OPSa25ENnrF0Qv70DG49ZngfdygJZubjo3TOgBA3pJ4&s=_C6i1KPplQGcWvQYPkrGx7V3TjKDJvqt3KG-vcdU2K4&e= > > > > > > Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > > > It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > > > > > > I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) > > > > > > Can you explain the reason for having a user space interface and DT property? > > I thought we had concluded earlier that we wouldn't need that, but it's possible > > that I missed something in the discussion since then. > > I don't think the sysfs knob is needed, this being said, after thinking > a bit more about mastership handover and the secondary master case, I > think we have something important to solve. > > When a master is not in control of the bus, it gets informed of devices > present on the bus by monitoring DAA or DEFSLVS broadcast events. That > means the secondary master should populate the bus with I3C/I2C devices > on such events, but that's not enough, because DEFSLVS/DAA do not > provide all device info. Some of them (like read/write/ibi limitations) > require extra CCC commands, and, to send those CCC commands, the > secondary master must claim the bus. We could add a case where we > declare devices as partially discovered until the master acquires > ownership of the bus, but that means part of the data returned by > i3c_device_get_info() will be inaccurate, which might have an impact on > some i3c driver ->probe() functions. > > How do you want to handle cases when secondary master joins the bus after > DEFSLVS? Of course we can send DEFSLVS after secondary master joins the bus. That's already the case ;-). Every time the current master discovers another master, it's sends a DEFSLVS at the end of the DAA procedure. > > We could also say that partially discovered devices should not be > registered to the device model, but we then hit the problem of "who can > force the secondary master to claim the bus if there's no users?". > > Now I feel like I missed something. Do you want to populate second instance > of the same physical bus? If yes, then we don't need to have reference > between masters in DT. This is the discussion we've had about 1 month ago with Arnd, Wolfram and Peter, and the conclusion was that 2 different masters connected to the same physical bus should expose 2 different buses (which means having the same physical devices exposed 2 times in Linux).
On Thu, 6 Sep 2018 14:50:03 +0100 vitor <Vitor.Soares@synopsys.com> wrote: > Hi, > > > On 06-09-2018 14:20, Boris Brezillon wrote: > > On Thu, 6 Sep 2018 15:14:37 +0200 > > Boris Brezillon <boris.brezillon@bootlin.com> wrote: > > > >> On Thu, 6 Sep 2018 14:59:46 +0200 > >> Arnd Bergmann <arnd@arndb.de> wrote: > >> > >>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > >>>> Hi Boris, Vitor, > >>>> > >>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e= > >>>> > >>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > >>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > >>>> > >>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) > >>> > >>> Can you explain the reason for having a user space interface and DT property? > >>> I thought we had concluded earlier that we wouldn't need that, but it's possible > >>> that I missed something in the discussion since then. > >> I don't think the sysfs knob is needed, this being said, after thinking > >> a bit more about mastership handover and the secondary master case, I > >> think we have something important to solve. > >> > >> When a master is not in control of the bus, it gets informed of devices > >> present on the bus by monitoring DAA or DEFSLVS broadcast events. That > >> means the secondary master should populate the bus with I3C/I2C devices > >> on such events, but that's not enough, because DEFSLVS/DAA do not > >> provide all device info.Some of them (like read/write/ibi limitations) > >> require extra CCC commands, and, to send those CCC commands, the > >> secondary master must claim the bus. We could add a case where we > >> declare devices as partially discovered until the master acquires > >> ownership of the bus, but that means part of the data returned by > >> i3c_device_get_info() will be inaccurate, which might have an impact on > >> some i3c driver ->probe() functions. > > Hm, one possible solution would be to register partially discovered > > devices to the device model and let i3c_device_get_info() claim the bus > > and request missing data when needed. This way, if the driver needs to > > call i3c_device_get_info() in its probe path, it should work just fine. > > Why don't use the i3c_master_add_i3c_dev_locked that job? It create, > attach and retrieve the device info. When will you call i3c_master_add_i3c_dev_locked()? After receiving a DEFSLVS interrupt/event? When that happens you're not in control of the bus, which means you'll have to force bus ownership handover. Is this really what we want? These are not rhetorical questions, I'm really asking for your opinion here. > This can be triggered after the secondary master receive ENEC MR until > them is keep in the driver memory. But that means no-one will actually trigger a mastership request, because devices won't be registered until all info are available. If we take this path, we should have a way to explicitly trigger a mastership request (sysfs knob or any other means).
On 9/6/18, 4:10 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
EXTERNAL MAIL
On Thu, 6 Sep 2018 13:47:29 +0000
Przemyslaw Gaj <pgaj@cadence.com> wrote:
> On 9/6/18, 3:14 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
>
> EXTERNAL MAIL
>
>
> On Thu, 6 Sep 2018 14:59:46 +0200
> Arnd Bergmann <arnd@arndb.de> wrote:
>
> > On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote:
> > >
> > > Hi Boris, Vitor,
> > >
> > > This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature.
> > > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=CMnAfM_OfpqcWZRfiqcRWw&m=OPSa25ENnrF0Qv70DG49ZngfdygJZubjo3TOgBA3pJ4&s=_C6i1KPplQGcWvQYPkrGx7V3TjKDJvqt3KG-vcdU2K4&e=
> > >
> > > Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters.
> > > It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device.
> > >
> > > I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :)
> >
> >
> > Can you explain the reason for having a user space interface and DT property?
> > I thought we had concluded earlier that we wouldn't need that, but it's possible
> > that I missed something in the discussion since then.
>
> I don't think the sysfs knob is needed, this being said, after thinking
> a bit more about mastership handover and the secondary master case, I
> think we have something important to solve.
>
> When a master is not in control of the bus, it gets informed of devices
> present on the bus by monitoring DAA or DEFSLVS broadcast events. That
> means the secondary master should populate the bus with I3C/I2C devices
> on such events, but that's not enough, because DEFSLVS/DAA do not
> provide all device info. Some of them (like read/write/ibi limitations)
> require extra CCC commands, and, to send those CCC commands, the
> secondary master must claim the bus. We could add a case where we
> declare devices as partially discovered until the master acquires
> ownership of the bus, but that means part of the data returned by
> i3c_device_get_info() will be inaccurate, which might have an impact on
> some i3c driver ->probe() functions.
>
> How do you want to handle cases when secondary master joins the bus after
> DEFSLVS? Of course we can send DEFSLVS after secondary master joins the bus.
That's already the case ;-). Every time the current master discovers
another master, it's sends a DEFSLVS at the end of the DAA procedure.
>
> We could also say that partially discovered devices should not be
> registered to the device model, but we then hit the problem of "who can
> force the secondary master to claim the bus if there's no users?".
>
> Now I feel like I missed something. Do you want to populate second instance
> of the same physical bus? If yes, then we don't need to have reference
> between masters in DT.
This is the discussion we've had about 1 month ago with Arnd, Wolfram
and Peter, and the conclusion was that 2 different masters connected to
the same physical bus should expose 2 different buses (which means
having the same physical devices exposed 2 times in Linux).
Ok, I implemented it after our discussion, I think it was in May. I even had
version where every master had own bus.
Hi Boris, On 06-09-2018 15:14, Boris Brezillon wrote: > On Thu, 6 Sep 2018 14:50:03 +0100 > vitor <Vitor.Soares@synopsys.com> wrote: > >> Hi, >> >> >> On 06-09-2018 14:20, Boris Brezillon wrote: >>> On Thu, 6 Sep 2018 15:14:37 +0200 >>> Boris Brezillon <boris.brezillon@bootlin.com> wrote: >>> >>>> On Thu, 6 Sep 2018 14:59:46 +0200 >>>> Arnd Bergmann <arnd@arndb.de> wrote: >>>> >>>>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: >>>>>> Hi Boris, Vitor, >>>>>> >>>>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. >>>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e= >>>>>> >>>>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. >>>>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. >>>>>> >>>>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) >>>>> Can you explain the reason for having a user space interface and DT property? >>>>> I thought we had concluded earlier that we wouldn't need that, but it's possible >>>>> that I missed something in the discussion since then. >>>> I don't think the sysfs knob is needed, this being said, after thinking >>>> a bit more about mastership handover and the secondary master case, I >>>> think we have something important to solve. >>>> >>>> When a master is not in control of the bus, it gets informed of devices >>>> present on the bus by monitoring DAA or DEFSLVS broadcast events. That >>>> means the secondary master should populate the bus with I3C/I2C devices >>>> on such events, but that's not enough, because DEFSLVS/DAA do not >>>> provide all device info.Some of them (like read/write/ibi limitations) >>>> require extra CCC commands, and, to send those CCC commands, the >>>> secondary master must claim the bus. We could add a case where we >>>> declare devices as partially discovered until the master acquires >>>> ownership of the bus, but that means part of the data returned by >>>> i3c_device_get_info() will be inaccurate, which might have an impact on >>>> some i3c driver ->probe() functions. >>> Hm, one possible solution would be to register partially discovered >>> devices to the device model and let i3c_device_get_info() claim the bus >>> and request missing data when needed. This way, if the driver needs to >>> call i3c_device_get_info() in its probe path, it should work just fine. >> Why don't use the i3c_master_add_i3c_dev_locked that job? It create, >> attach and retrieve the device info. > When will you call i3c_master_add_i3c_dev_locked()? After receiving a > DEFSLVS interrupt/event? When that happens you're not in control of the > bus, which means you'll have to force bus ownership handover. Is this > really what we want? > > These are not rhetorical questions, I'm really asking for your opinion > here. What I understand from last discussion was that every time that device need to do something (private messages) on the bus and don't have the bus control it should force ownership handover. If my understanding is correct this can be also applied to CCC commands. > >> This can be triggered after the secondary master receive ENEC MR until >> them is keep in the driver memory. > But that means no-one will actually trigger a mastership request, > because devices won't be registered until all info are available. If we > take this path, we should have a way to explicitly trigger a mastership > request (sysfs knob or any other means). By the current flow that we have now, we enable the IBI events at the end of .do_daa. At this time the main master bus is initialized with all devices. From the point of view of secondary master, it first participate on DAA process, next it send its info (Main master do i3c_master_retrieve_dev_info()) and them receive DEFSLVS. In the stage it cannot request the bus mastership it need the MR enable. So, what I would suggest is to keep DEFSLVS data in secondary master driver memory . When secondary master receive the MR enable, it can get the bus ownership and do i3c_master_add_i3c_dev_locked() and each device in DEFSLVS command. After this step delegate the bus ownership to the main master. What do you think about this? Best regards, Vitor Soares
On Thu, 6 Sep 2018 16:17:58 +0100 vitor <Vitor.Soares@synopsys.com> wrote: > Hi Boris, > > > On 06-09-2018 15:14, Boris Brezillon wrote: > > On Thu, 6 Sep 2018 14:50:03 +0100 > > vitor <Vitor.Soares@synopsys.com> wrote: > > > >> Hi, > >> > >> > >> On 06-09-2018 14:20, Boris Brezillon wrote: > >>> On Thu, 6 Sep 2018 15:14:37 +0200 > >>> Boris Brezillon <boris.brezillon@bootlin.com> wrote: > >>> > >>>> On Thu, 6 Sep 2018 14:59:46 +0200 > >>>> Arnd Bergmann <arnd@arndb.de> wrote: > >>>> > >>>>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > >>>>>> Hi Boris, Vitor, > >>>>>> > >>>>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > >>>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e= > >>>>>> > >>>>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > >>>>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > >>>>>> > >>>>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) > >>>>> Can you explain the reason for having a user space interface and DT property? > >>>>> I thought we had concluded earlier that we wouldn't need that, but it's possible > >>>>> that I missed something in the discussion since then. > >>>> I don't think the sysfs knob is needed, this being said, after thinking > >>>> a bit more about mastership handover and the secondary master case, I > >>>> think we have something important to solve. > >>>> > >>>> When a master is not in control of the bus, it gets informed of devices > >>>> present on the bus by monitoring DAA or DEFSLVS broadcast events. That > >>>> means the secondary master should populate the bus with I3C/I2C devices > >>>> on such events, but that's not enough, because DEFSLVS/DAA do not > >>>> provide all device info.Some of them (like read/write/ibi limitations) > >>>> require extra CCC commands, and, to send those CCC commands, the > >>>> secondary master must claim the bus. We could add a case where we > >>>> declare devices as partially discovered until the master acquires > >>>> ownership of the bus, but that means part of the data returned by > >>>> i3c_device_get_info() will be inaccurate, which might have an impact on > >>>> some i3c driver ->probe() functions. > >>> Hm, one possible solution would be to register partially discovered > >>> devices to the device model and let i3c_device_get_info() claim the bus > >>> and request missing data when needed. This way, if the driver needs to > >>> call i3c_device_get_info() in its probe path, it should work just fine. > >> Why don't use the i3c_master_add_i3c_dev_locked that job? It create, > >> attach and retrieve the device info. > > When will you call i3c_master_add_i3c_dev_locked()? After receiving a > > DEFSLVS interrupt/event? When that happens you're not in control of the > > bus, which means you'll have to force bus ownership handover. Is this > > really what we want? > > > > These are not rhetorical questions, I'm really asking for your opinion > > here. > What I understand from last discussion was that every time that device > need to do something (private messages) on the bus and don't have the > bus control it should force ownership handover. > If my understanding is correct this can be also applied to CCC commands. Sure, but the question is more, when do we want to do that? > > > > >> This can be triggered after the secondary master receive ENEC MR until > >> them is keep in the driver memory. > > But that means no-one will actually trigger a mastership request, > > because devices won't be registered until all info are available. If we > > take this path, we should have a way to explicitly trigger a mastership > > request (sysfs knob or any other means). > By the current flow that we have now, we enable the IBI events at the > end of .do_daa. At this time the main master bus is initialized with all > devices. > > From the point of view of secondary master, it first participate on DAA > process, next it send its info (Main master do > i3c_master_retrieve_dev_info()) and them receive DEFSLVS. In the stage > it cannot request the bus mastership it need the MR enable. You mean the broadcast ENEC(MR) event, right? Then yes, this one is probably missing (or maybe I added it in the master controller driver, I don't remember). > > So, what I would suggest is to keep DEFSLVS data in secondary master > driver memory . When secondary master receive the MR enable, it can get > the bus ownership and do i3c_master_add_i3c_dev_locked() and each device > in DEFSLVS command. After this step delegate the bus ownership to the > main master. That's an option, indeed. > > What do you think about this? Sounds like a good start. If MR is rejected by the master, we will just keep all devices in an unregistered state. We can also add a sysfs entry to manually re-trigger this operation in case the initial one failed.
On 9/6/18, 6:07 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
EXTERNAL MAIL
On Thu, 6 Sep 2018 16:17:58 +0100
vitor <Vitor.Soares@synopsys.com> wrote:
> Hi Boris,
>
>
> On 06-09-2018 15:14, Boris Brezillon wrote:
> > On Thu, 6 Sep 2018 14:50:03 +0100
> > vitor <Vitor.Soares@synopsys.com> wrote:
> >
> >> Hi,
> >>
> >>
> >> On 06-09-2018 14:20, Boris Brezillon wrote:
> >>> On Thu, 6 Sep 2018 15:14:37 +0200
> >>> Boris Brezillon <boris.brezillon@bootlin.com> wrote:
> >>>
> >>>> On Thu, 6 Sep 2018 14:59:46 +0200
> >>>> Arnd Bergmann <arnd@arndb.de> wrote:
> >>>>
> >>>>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote:
> >>>>>> Hi Boris, Vitor,
> >>>>>>
> >>>>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature.
> >>>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e=
> >>>>>>
> >>>>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters.
> >>>>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device.
> >>>>>>
> >>>>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :)
> >>>>> Can you explain the reason for having a user space interface and DT property?
> >>>>> I thought we had concluded earlier that we wouldn't need that, but it's possible
> >>>>> that I missed something in the discussion since then.
> >>>> I don't think the sysfs knob is needed, this being said, after thinking
> >>>> a bit more about mastership handover and the secondary master case, I
> >>>> think we have something important to solve.
> >>>>
> >>>> When a master is not in control of the bus, it gets informed of devices
> >>>> present on the bus by monitoring DAA or DEFSLVS broadcast events. That
> >>>> means the secondary master should populate the bus with I3C/I2C devices
> >>>> on such events, but that's not enough, because DEFSLVS/DAA do not
> >>>> provide all device info.Some of them (like read/write/ibi limitations)
> >>>> require extra CCC commands, and, to send those CCC commands, the
> >>>> secondary master must claim the bus. We could add a case where we
> >>>> declare devices as partially discovered until the master acquires
> >>>> ownership of the bus, but that means part of the data returned by
> >>>> i3c_device_get_info() will be inaccurate, which might have an impact on
> >>>> some i3c driver ->probe() functions.
> >>> Hm, one possible solution would be to register partially discovered
> >>> devices to the device model and let i3c_device_get_info() claim the bus
> >>> and request missing data when needed. This way, if the driver needs to
> >>> call i3c_device_get_info() in its probe path, it should work just fine.
> >> Why don't use the i3c_master_add_i3c_dev_locked that job? It create,
> >> attach and retrieve the device info.
> > When will you call i3c_master_add_i3c_dev_locked()? After receiving a
> > DEFSLVS interrupt/event? When that happens you're not in control of the
> > bus, which means you'll have to force bus ownership handover. Is this
> > really what we want?
> >
> > These are not rhetorical questions, I'm really asking for your opinion
> > here.
> What I understand from last discussion was that every time that device
> need to do something (private messages) on the bus and don't have the
> bus control it should force ownership handover.
> If my understanding is correct this can be also applied to CCC commands.
Sure, but the question is more, when do we want to do that?
>
> >
> >> This can be triggered after the secondary master receive ENEC MR until
> >> them is keep in the driver memory.
> > But that means no-one will actually trigger a mastership request,
> > because devices won't be registered until all info are available. If we
> > take this path, we should have a way to explicitly trigger a mastership
> > request (sysfs knob or any other means).
> By the current flow that we have now, we enable the IBI events at the
> end of .do_daa. At this time the main master bus is initialized with all
> devices.
>
> From the point of view of secondary master, it first participate on DAA
> process, next it send its info (Main master do
> i3c_master_retrieve_dev_info()) and them receive DEFSLVS. In the stage
> it cannot request the bus mastership it need the MR enable.
You mean the broadcast ENEC(MR) event, right? Then yes, this one is
probably missing (or maybe I added it in the master controller driver,
I don't remember).
>
> So, what I would suggest is to keep DEFSLVS data in secondary master
> driver memory . When secondary master receive the MR enable, it can get
> the bus ownership and do i3c_master_add_i3c_dev_locked() and each device
> in DEFSLVS command. After this step delegate the bus ownership to the
> main master.
That's an option, indeed.
>
> What do you think about this?
Sounds like a good start. If MR is rejected by the master, we will just
keep all devices in an unregistered state. We can also add a sysfs
entry to manually re-trigger this operation in case the initial one
failed.
This everything sounds like my previous version. Enec event was missing,
everything was triggered manually from sysfs.
Hi Boris, Vitor,
On 9/6/18, 6:07 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote:
EXTERNAL MAIL
On Thu, 6 Sep 2018 16:17:58 +0100
vitor <Vitor.Soares@synopsys.com> wrote:
> Hi Boris,
>
>
> On 06-09-2018 15:14, Boris Brezillon wrote:
> > On Thu, 6 Sep 2018 14:50:03 +0100
> > vitor <Vitor.Soares@synopsys.com> wrote:
> >
> >> Hi,
> >>
> >>
> >> On 06-09-2018 14:20, Boris Brezillon wrote:
> >>> On Thu, 6 Sep 2018 15:14:37 +0200
> >>> Boris Brezillon <boris.brezillon@bootlin.com> wrote:
> >>>
> >>>> On Thu, 6 Sep 2018 14:59:46 +0200
> >>>> Arnd Bergmann <arnd@arndb.de> wrote:
> >>>>
> >>>>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote:
> >>>>>> Hi Boris, Vitor,
> >>>>>>
> >>>>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature.
> >>>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e=
> >>>>>>
> >>>>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters.
> >>>>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device.
> >>>>>>
> >>>>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :)
> >>>>> Can you explain the reason for having a user space interface and DT property?
> >>>>> I thought we had concluded earlier that we wouldn't need that, but it's possible
> >>>>> that I missed something in the discussion since then.
> >>>> I don't think the sysfs knob is needed, this being said, after thinking
> >>>> a bit more about mastership handover and the secondary master case, I
> >>>> think we have something important to solve.
> >>>>
> >>>> When a master is not in control of the bus, it gets informed of devices
> >>>> present on the bus by monitoring DAA or DEFSLVS broadcast events. That
> >>>> means the secondary master should populate the bus with I3C/I2C devices
> >>>> on such events, but that's not enough, because DEFSLVS/DAA do not
> >>>> provide all device info.Some of them (like read/write/ibi limitations)
> >>>> require extra CCC commands, and, to send those CCC commands, the
> >>>> secondary master must claim the bus. We could add a case where we
> >>>> declare devices as partially discovered until the master acquires
> >>>> ownership of the bus, but that means part of the data returned by
> >>>> i3c_device_get_info() will be inaccurate, which might have an impact on
> >>>> some i3c driver ->probe() functions.
> >>> Hm, one possible solution would be to register partially discovered
> >>> devices to the device model and let i3c_device_get_info() claim the bus
> >>> and request missing data when needed. This way, if the driver needs to
> >>> call i3c_device_get_info() in its probe path, it should work just fine.
> >> Why don't use the i3c_master_add_i3c_dev_locked that job? It create,
> >> attach and retrieve the device info.
> > When will you call i3c_master_add_i3c_dev_locked()? After receiving a
> > DEFSLVS interrupt/event? When that happens you're not in control of the
> > bus, which means you'll have to force bus ownership handover. Is this
> > really what we want?
> >
> > These are not rhetorical questions, I'm really asking for your opinion
> > here.
> What I understand from last discussion was that every time that device
> need to do something (private messages) on the bus and don't have the
> bus control it should force ownership handover.
> If my understanding is correct this can be also applied to CCC commands.
Sure, but the question is more, when do we want to do that?
>
> >
> >> This can be triggered after the secondary master receive ENEC MR until
> >> them is keep in the driver memory.
> > But that means no-one will actually trigger a mastership request,
> > because devices won't be registered until all info are available. If we
> > take this path, we should have a way to explicitly trigger a mastership
> > request (sysfs knob or any other means).
> By the current flow that we have now, we enable the IBI events at the
> end of .do_daa. At this time the main master bus is initialized with all
> devices.
>
> From the point of view of secondary master, it first participate on DAA
> process, next it send its info (Main master do
> i3c_master_retrieve_dev_info()) and them receive DEFSLVS. In the stage
> it cannot request the bus mastership it need the MR enable.
You mean the broadcast ENEC(MR) event, right? Then yes, this one is
probably missing (or maybe I added it in the master controller driver,
I don't remember).
>
> So, what I would suggest is to keep DEFSLVS data in secondary master
> driver memory . When secondary master receive the MR enable, it can get
> the bus ownership and do i3c_master_add_i3c_dev_locked() and each device
> in DEFSLVS command. After this step delegate the bus ownership to the
> main master.
That's an option, indeed.
>
> What do you think about this?
Sounds like a good start. If MR is rejected by the master, we will just
keep all devices in an unregistered state. We can also add a sysfs
entry to manually re-trigger this operation in case the initial one
failed.
I found that version. I added also mastership request after ENEC(MR) event to run
tests and verify if everything works correctly. It looked quite simple. Secondary master
does not give control back automatically after bus initialization and master doesn't
yet request mastership when device driver wants to use the bus / transfer data.
This can be the base for further works.
https://github.com/przemekgaj/i3c-linux/tree/mastership_takeover
Regards,
Przemek
Hi, On 06-09-2018 17:17, Przemyslaw Gaj wrote: > > On 9/6/18, 6:07 PM, "Boris Brezillon" <boris.brezillon@bootlin.com> wrote: > > EXTERNAL MAIL > > > On Thu, 6 Sep 2018 16:17:58 +0100 > vitor <Vitor.Soares@synopsys.com> wrote: > > > Hi Boris, > > > > > > On 06-09-2018 15:14, Boris Brezillon wrote: > > > On Thu, 6 Sep 2018 14:50:03 +0100 > > > vitor <Vitor.Soares@synopsys.com> wrote: > > > > > >> Hi, > > >> > > >> > > >> On 06-09-2018 14:20, Boris Brezillon wrote: > > >>> On Thu, 6 Sep 2018 15:14:37 +0200 > > >>> Boris Brezillon <boris.brezillon@bootlin.com> wrote: > > >>> > > >>>> On Thu, 6 Sep 2018 14:59:46 +0200 > > >>>> Arnd Bergmann <arnd@arndb.de> wrote: > > >>>> > > >>>>> On Thu, Sep 6, 2018 at 2:43 PM Przemyslaw Gaj <pgaj@cadence.com> wrote: > > >>>>>> Hi Boris, Vitor, > > >>>>>> > > >>>>>> This repository does not contain full kernel sources, but it should be enough to discuss mastership request feature. > > >>>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_przemekgaj_i3c-2Dlinux_commit_d54fe68a9d3e573c0c454a2c6f1afafc20142ec5&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=Q9DWw3KGmshGw0f5QTiffbpbESyUlPx6KmASuDBtX9Y&s=HHE_y1kyMszJvP_tSP9JkDlPYxDywBeHwkMGgCR11uI&e= > > >>>>>> > > >>>>>> Please keep in mind that this is initial version, but mastership works correctly. I added one property to DT to reflect relationship between masters. > > >>>>>> It is possible to request mastership on demand (using sysfs. Useful in case when Linux machine is equipped only with secondary master controller) or automatically change operation mode when device driver wants to read/write something from/to device. > > >>>>>> > > >>>>>> I'm sure I will have to rework something because this was implemented on sources from PATCH v4. I saw that Boris released v7 yesterday :) > > >>>>> Can you explain the reason for having a user space interface and DT property? > > >>>>> I thought we had concluded earlier that we wouldn't need that, but it's possible > > >>>>> that I missed something in the discussion since then. > > >>>> I don't think the sysfs knob is needed, this being said, after thinking > > >>>> a bit more about mastership handover and the secondary master case, I > > >>>> think we have something important to solve. > > >>>> > > >>>> When a master is not in control of the bus, it gets informed of devices > > >>>> present on the bus by monitoring DAA or DEFSLVS broadcast events. That > > >>>> means the secondary master should populate the bus with I3C/I2C devices > > >>>> on such events, but that's not enough, because DEFSLVS/DAA do not > > >>>> provide all device info.Some of them (like read/write/ibi limitations) > > >>>> require extra CCC commands, and, to send those CCC commands, the > > >>>> secondary master must claim the bus. We could add a case where we > > >>>> declare devices as partially discovered until the master acquires > > >>>> ownership of the bus, but that means part of the data returned by > > >>>> i3c_device_get_info() will be inaccurate, which might have an impact on > > >>>> some i3c driver ->probe() functions. > > >>> Hm, one possible solution would be to register partially discovered > > >>> devices to the device model and let i3c_device_get_info() claim the bus > > >>> and request missing data when needed. This way, if the driver needs to > > >>> call i3c_device_get_info() in its probe path, it should work just fine. > > >> Why don't use the i3c_master_add_i3c_dev_locked that job? It create, > > >> attach and retrieve the device info. > > > When will you call i3c_master_add_i3c_dev_locked()? After receiving a > > > DEFSLVS interrupt/event? When that happens you're not in control of the > > > bus, which means you'll have to force bus ownership handover. Is this > > > really what we want? > > > > > > These are not rhetorical questions, I'm really asking for your opinion > > > here. > > What I understand from last discussion was that every time that device > > need to do something (private messages) on the bus and don't have the > > bus control it should force ownership handover. > > If my understanding is correct this can be also applied to CCC commands. > > Sure, but the question is more, when do we want to do that? > > > > > > > > >> This can be triggered after the secondary master receive ENEC MR until > > >> them is keep in the driver memory. > > > But that means no-one will actually trigger a mastership request, > > > because devices won't be registered until all info are available. If we > > > take this path, we should have a way to explicitly trigger a mastership > > > request (sysfs knob or any other means). > > By the current flow that we have now, we enable the IBI events at the > > end of .do_daa. At this time the main master bus is initialized with all > > devices. > > > > From the point of view of secondary master, it first participate on DAA > > process, next it send its info (Main master do > > i3c_master_retrieve_dev_info()) and them receive DEFSLVS. In the stage > > it cannot request the bus mastership it need the MR enable. > > You mean the broadcast ENEC(MR) event, right? Then yes, this one is > probably missing (or maybe I added it in the master controller driver, > I don't remember). > > > > > So, what I would suggest is to keep DEFSLVS data in secondary master > > driver memory . When secondary master receive the MR enable, it can get > > the bus ownership and do i3c_master_add_i3c_dev_locked() and each device > > in DEFSLVS command. After this step delegate the bus ownership to the > > main master. > > That's an option, indeed. > > > > > What do you think about this? > > Sounds like a good start. If MR is rejected by the master, we will just > keep all devices in an unregistered state. We can also add a sysfs > entry to manually re-trigger this operation in case the initial one > failed. > > This everything sounds like my previous version. Enec event was missing, > everything was triggered manually from sysfs. > Does make sense to do the ->bus_init() only after receive the first ENEC-MR event? The bus initialization assume that we already know the I2C devices present on the line (bus->mode) and i3c_master_set_info only have meaning if the device will act as a master otherwise it can act as "slave". Best regards, Vitor Soares
diff --git a/drivers/Kconfig b/drivers/Kconfig index 95b9ccc08165..80f6aebc896f 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -55,6 +55,8 @@ source "drivers/char/Kconfig" source "drivers/i2c/Kconfig" +source "drivers/i3c/Kconfig" + source "drivers/spi/Kconfig" source "drivers/spmi/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 24cd47014657..999239dc29d4 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -111,7 +111,7 @@ obj-$(CONFIG_SERIO) += input/serio/ obj-$(CONFIG_GAMEPORT) += input/gameport/ obj-$(CONFIG_INPUT) += input/ obj-$(CONFIG_RTC_LIB) += rtc/ -obj-y += i2c/ media/ +obj-y += i2c/ i3c/ media/ obj-$(CONFIG_PPS) += pps/ obj-y += ptp/ obj-$(CONFIG_W1) += w1/ diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig new file mode 100644 index 000000000000..30a441506f61 --- /dev/null +++ b/drivers/i3c/Kconfig @@ -0,0 +1,24 @@ +# SPDX-License-Identifier: GPL-2.0 + +menuconfig I3C + tristate "I3C support" + select I2C + help + I3C is a serial protocol standardized by the MIPI alliance. + + It's supposed to be backward compatible with I2C while providing + support for high speed transfers and native interrupt support + without the need for extra pins. + + The I3C protocol also standardizes the slave device types and is + mainly designed to communicate with sensors. + + If you want I3C support, you should say Y here and also to the + specific driver for your bus adapter(s) below. + + This I3C support can also be built as a module. If so, the module + will be called i3c. + +if I3C +source "drivers/i3c/master/Kconfig" +endif # I3C diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile new file mode 100644 index 000000000000..3b6d1502d6e6 --- /dev/null +++ b/drivers/i3c/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 +i3c-y := core.o device.o master.o +obj-$(CONFIG_I3C) += i3c.o +obj-$(CONFIG_I3C) += master/ diff --git a/drivers/i3c/core.c b/drivers/i3c/core.c new file mode 100644 index 000000000000..5c62192ff876 --- /dev/null +++ b/drivers/i3c/core.c @@ -0,0 +1,606 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#include <linux/device.h> +#include <linux/idr.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of_device.h> +#include <linux/rwsem.h> +#include <linux/slab.h> + +#include "internals.h" + +static DEFINE_IDR(i3c_bus_idr); +static DEFINE_MUTEX(i3c_core_lock); + +/** + * i3c_bus_maintenance_lock - Lock the bus for a maintenance operation + * @bus: I3C bus to take the lock on + * + * This function takes the bus lock so that no other operations can occur on + * the bus. This is needed for all kind of bus maintenance operation, like + * - enabling/disabling slave events + * - re-triggering DAA + * - changing the dynamic address of a device + * - relinquishing mastership + * - ... + * + * The reason for this kind of locking is that we don't want drivers and core + * logic to rely on I3C device information that could be changed behind their + * back. + */ +void i3c_bus_maintenance_lock(struct i3c_bus *bus) +{ + down_write(&bus->lock); +} +EXPORT_SYMBOL_GPL(i3c_bus_maintenance_lock); + +/** + * i3c_bus_maintenance_unlock - Release the bus lock after a maintenance + * operation + * @bus: I3C bus to release the lock on + * + * Should be called when the bus maintenance operation is done. See + * i3c_bus_maintenance_lock() for more details on what these maintenance + * operations are. + */ +void i3c_bus_maintenance_unlock(struct i3c_bus *bus) +{ + up_write(&bus->lock); +} +EXPORT_SYMBOL_GPL(i3c_bus_maintenance_unlock); + +/** + * i3c_bus_normaluse_lock - Lock the bus for a normal operation + * @bus: I3C bus to take the lock on + * + * This function takes the bus lock for any operation that is not a maintenance + * operation (see i3c_bus_maintenance_lock() for a non-exhaustive list of + * maintenance operations). Basically all communications with I3C devices are + * normal operations (HDR, SDR transfers or CCC commands that do not change bus + * state or I3C dynamic address). + * + * Note that this lock is not guaranteeing serialization of normal operations. + * In other words, transfer requests passed to the I3C master can be submitted + * in parallel and I3C master drivers have to use their own locking to make + * sure two different communications are not inter-mixed, or access to the + * output/input queue is not done while the engine is busy. + */ +void i3c_bus_normaluse_lock(struct i3c_bus *bus) +{ + down_read(&bus->lock); +} +EXPORT_SYMBOL_GPL(i3c_bus_normaluse_lock); + +/** + * i3c_bus_normaluse_unlock - Release the bus lock after a normal operation + * @bus: I3C bus to release the lock on + * + * Should be called when a normal operation is done. See + * i3c_bus_normaluse_lock() for more details on what these normal operations + * are. + */ +void i3c_bus_normaluse_unlock(struct i3c_bus *bus) +{ + up_read(&bus->lock); +} +EXPORT_SYMBOL_GPL(i3c_bus_normaluse_unlock); + +static ssize_t bcr_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cdev->bus); + ret = sprintf(buf, "%x\n", i3cdev->desc->info.bcr); + i3c_bus_normaluse_unlock(i3cdev->bus); + + return ret; +} +static DEVICE_ATTR_RO(bcr); + +static ssize_t dcr_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cdev->bus); + ret = sprintf(buf, "%x\n", i3cdev->desc->info.dcr); + i3c_bus_normaluse_unlock(i3cdev->bus); + + return ret; +} +static DEVICE_ATTR_RO(dcr); + +static ssize_t pid_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cdev->bus); + ret = sprintf(buf, "%llx\n", i3cdev->desc->info.pid); + i3c_bus_normaluse_unlock(i3cdev->bus); + + return ret; +} +static DEVICE_ATTR_RO(pid); + +static ssize_t dynamic_address_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cdev->bus); + ret = sprintf(buf, "%02x\n", i3cdev->desc->info.dyn_addr); + i3c_bus_normaluse_unlock(i3cdev->bus); + + return ret; +} +static DEVICE_ATTR_RO(dynamic_address); + +static const char * const hdrcap_strings[] = { + "hdr-ddr", "hdr-tsp", "hdr-tsl", +}; + +static ssize_t hdrcap_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + ssize_t offset = 0, ret; + unsigned long caps; + int mode; + + i3c_bus_normaluse_lock(i3cdev->bus); + caps = i3cdev->desc->info.hdr_cap; + for_each_set_bit(mode, &caps, 8) { + if (mode >= ARRAY_SIZE(hdrcap_strings)) + break; + + if (!hdrcap_strings[mode]) + continue; + + ret = sprintf(buf + offset, offset ? " %s" : "%s", + hdrcap_strings[mode]); + if (ret < 0) + goto out; + + offset += ret; + } + + ret = sprintf(buf + offset, "\n"); + if (ret < 0) + goto out; + + ret = offset + ret; + +out: + i3c_bus_normaluse_unlock(i3cdev->bus); + + return ret; +} +static DEVICE_ATTR_RO(hdrcap); + +static struct attribute *i3c_device_attrs[] = { + &dev_attr_bcr.attr, + &dev_attr_dcr.attr, + &dev_attr_pid.attr, + &dev_attr_dynamic_address.attr, + &dev_attr_hdrcap.attr, + NULL, +}; +ATTRIBUTE_GROUPS(i3c_device); + +static int i3c_device_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + struct i3c_device_info devinfo; + u16 manuf, part, ext; + + i3c_device_get_info(i3cdev, &devinfo); + manuf = I3C_PID_MANUF_ID(devinfo.pid); + part = I3C_PID_PART_ID(devinfo.pid); + ext = I3C_PID_EXTRA_INFO(devinfo.pid); + + if (I3C_PID_RND_LOWER_32BITS(devinfo.pid)) + return add_uevent_var(env, "MODALIAS=i3c:dcr%02Xmanuf%04X", + devinfo.dcr, manuf); + + return add_uevent_var(env, + "MODALIAS=i3c:dcr%02Xmanuf%04Xpart%04xext%04x", + devinfo.dcr, manuf, part, ext); +} + +const struct device_type i3c_device_type = { + .groups = i3c_device_groups, + .uevent = i3c_device_uevent, +}; + +const struct device_type i3c_master_type = { + .groups = i3c_device_groups, +}; + +static const struct i3c_device_id * +i3c_device_match_id(struct i3c_device *i3cdev, + const struct i3c_device_id *id_table) +{ + struct i3c_device_info devinfo; + const struct i3c_device_id *id; + + i3c_device_get_info(i3cdev, &devinfo); + + /* + * The lower 32bits of the provisional ID is just filled with a random + * value, try to match using DCR info. + */ + if (!I3C_PID_RND_LOWER_32BITS(devinfo.pid)) { + u16 manuf = I3C_PID_MANUF_ID(devinfo.pid); + u16 part = I3C_PID_PART_ID(devinfo.pid); + u16 ext_info = I3C_PID_EXTRA_INFO(devinfo.pid); + + /* First try to match by manufacturer/part ID. */ + for (id = id_table; id->match_flags != 0; id++) { + if ((id->match_flags & I3C_MATCH_MANUF_AND_PART) != + I3C_MATCH_MANUF_AND_PART) + continue; + + if (manuf != id->manuf_id || part != id->part_id) + continue; + + if ((id->match_flags & I3C_MATCH_EXTRA_INFO) && + ext_info != id->extra_info) + continue; + + return id; + } + } + + /* Fallback to DCR match. */ + for (id = id_table; id->match_flags != 0; id++) { + if ((id->match_flags & I3C_MATCH_DCR) && + id->dcr == devinfo.dcr) + return id; + } + + return NULL; +} + +static int i3c_device_match(struct device *dev, struct device_driver *drv) +{ + struct i3c_device *i3cdev; + struct i3c_driver *i3cdrv; + + if (dev->type != &i3c_device_type) + return 0; + + i3cdev = dev_to_i3cdev(dev); + i3cdrv = drv_to_i3cdrv(drv); + if (i3c_device_match_id(i3cdev, i3cdrv->id_table)) + return 1; + + return 0; +} + +static int i3c_device_probe(struct device *dev) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + struct i3c_driver *driver = drv_to_i3cdrv(dev->driver); + + return driver->probe(i3cdev); +} + +static int i3c_device_remove(struct device *dev) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + struct i3c_driver *driver = drv_to_i3cdrv(dev->driver); + int ret; + + ret = driver->remove(i3cdev); + if (ret) + return ret; + + i3c_device_free_ibi(i3cdev); + + return ret; +} + +struct bus_type i3c_bus_type = { + .name = "i3c", + .match = i3c_device_match, + .probe = i3c_device_probe, + .remove = i3c_device_remove, +}; + +enum i3c_addr_slot_status i3c_bus_get_addr_slot_status(struct i3c_bus *bus, + u16 addr) +{ + int status, bitpos = addr * 2; + + if (addr > I2C_MAX_ADDR) + return I3C_ADDR_SLOT_RSVD; + + status = bus->addrslots[bitpos / BITS_PER_LONG]; + status >>= bitpos % BITS_PER_LONG; + + return status & I3C_ADDR_SLOT_STATUS_MASK; +} + +void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr, + enum i3c_addr_slot_status status) +{ + int bitpos = addr * 2; + unsigned long *ptr; + + if (addr > I2C_MAX_ADDR) + return; + + ptr = bus->addrslots + (bitpos / BITS_PER_LONG); + *ptr &= ~(I3C_ADDR_SLOT_STATUS_MASK << (bitpos % BITS_PER_LONG)); + *ptr |= status << (bitpos % BITS_PER_LONG); +} + +bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr) +{ + enum i3c_addr_slot_status status; + + status = i3c_bus_get_addr_slot_status(bus, addr); + + return status == I3C_ADDR_SLOT_FREE; +} + +int i3c_bus_get_free_addr(struct i3c_bus *bus, u8 start_addr) +{ + enum i3c_addr_slot_status status; + u8 addr; + + for (addr = start_addr; addr < I3C_MAX_ADDR; addr++) { + status = i3c_bus_get_addr_slot_status(bus, addr); + if (status == I3C_ADDR_SLOT_FREE) + return addr; + } + + return -ENOMEM; +} + +static void i3c_bus_init_addrslots(struct i3c_bus *bus) +{ + int i; + + /* Addresses 0 to 7 are reserved. */ + for (i = 0; i < 8; i++) + i3c_bus_set_addr_slot_status(bus, i, I3C_ADDR_SLOT_RSVD); + + /* + * Reserve broadcast address and all addresses that might collide + * with the broadcast address when facing a single bit error. + */ + i3c_bus_set_addr_slot_status(bus, I3C_BROADCAST_ADDR, + I3C_ADDR_SLOT_RSVD); + for (i = 0; i < 7; i++) + i3c_bus_set_addr_slot_status(bus, I3C_BROADCAST_ADDR ^ BIT(i), + I3C_ADDR_SLOT_RSVD); +} + +static const char * const i3c_bus_mode_strings[] = { + [I3C_BUS_MODE_PURE] = "pure", + [I3C_BUS_MODE_MIXED_FAST] = "mixed-fast", + [I3C_BUS_MODE_MIXED_SLOW] = "mixed-slow", +}; + +static ssize_t mode_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cbus); + if (i3cbus->mode < 0 || + i3cbus->mode > ARRAY_SIZE(i3c_bus_mode_strings) || + !i3c_bus_mode_strings[i3cbus->mode]) + ret = sprintf(buf, "unknown\n"); + else + ret = sprintf(buf, "%s\n", i3c_bus_mode_strings[i3cbus->mode]); + i3c_bus_normaluse_unlock(i3cbus); + + return ret; +} +static DEVICE_ATTR_RO(mode); + +static ssize_t current_master_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cbus); + ret = sprintf(buf, "%d-%llx\n", i3cbus->id, + i3cbus->cur_master->info.pid); + i3c_bus_normaluse_unlock(i3cbus); + + return ret; +} +static DEVICE_ATTR_RO(current_master); + +static ssize_t i3c_scl_frequency_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cbus); + ret = sprintf(buf, "%ld\n", i3cbus->scl_rate.i3c); + i3c_bus_normaluse_unlock(i3cbus); + + return ret; +} +static DEVICE_ATTR_RO(i3c_scl_frequency); + +static ssize_t i2c_scl_frequency_show(struct device *dev, + struct device_attribute *da, + char *buf) +{ + struct i3c_bus *i3cbus = container_of(dev, struct i3c_bus, dev); + ssize_t ret; + + i3c_bus_normaluse_lock(i3cbus); + ret = sprintf(buf, "%ld\n", i3cbus->scl_rate.i2c); + i3c_bus_normaluse_unlock(i3cbus); + + return ret; +} +static DEVICE_ATTR_RO(i2c_scl_frequency); + +static struct attribute *i3c_busdev_attrs[] = { + &dev_attr_mode.attr, + &dev_attr_current_master.attr, + &dev_attr_i3c_scl_frequency.attr, + &dev_attr_i2c_scl_frequency.attr, + NULL, +}; +ATTRIBUTE_GROUPS(i3c_busdev); + +static void i3c_busdev_release(struct device *dev) +{ + struct i3c_bus *bus = container_of(dev, struct i3c_bus, dev); + + WARN_ON(!list_empty(&bus->devs.i2c) || !list_empty(&bus->devs.i3c)); + + mutex_lock(&i3c_core_lock); + idr_remove(&i3c_bus_idr, bus->id); + mutex_unlock(&i3c_core_lock); + + of_node_put(bus->dev.of_node); + kfree(bus); +} + +static const struct device_type i3c_busdev_type = { + .groups = i3c_busdev_groups, +}; + +void i3c_bus_unref(struct i3c_bus *bus) +{ + put_device(&bus->dev); +} + +struct i3c_bus *i3c_bus_create(struct device *parent) +{ + struct i3c_bus *i3cbus; + int ret; + + i3cbus = kzalloc(sizeof(*i3cbus), GFP_KERNEL); + if (!i3cbus) + return ERR_PTR(-ENOMEM); + + init_rwsem(&i3cbus->lock); + INIT_LIST_HEAD(&i3cbus->devs.i2c); + INIT_LIST_HEAD(&i3cbus->devs.i3c); + i3c_bus_init_addrslots(i3cbus); + i3cbus->mode = I3C_BUS_MODE_PURE; + i3cbus->dev.parent = parent; + i3cbus->dev.of_node = of_node_get(parent->of_node); + i3cbus->dev.bus = &i3c_bus_type; + i3cbus->dev.type = &i3c_busdev_type; + i3cbus->dev.release = i3c_busdev_release; + + mutex_lock(&i3c_core_lock); + ret = idr_alloc(&i3c_bus_idr, i3cbus, 0, 0, GFP_KERNEL); + mutex_unlock(&i3c_core_lock); + if (ret < 0) + goto err_free_bus; + + i3cbus->id = ret; + device_initialize(&i3cbus->dev); + + return i3cbus; + +err_free_bus: + kfree(i3cbus); + + return ERR_PTR(ret); +} + +void i3c_bus_unregister(struct i3c_bus *bus) +{ + device_unregister(&bus->dev); +} + +int i3c_bus_register(struct i3c_bus *i3cbus) +{ + struct i2c_dev_desc *desc; + + i3c_bus_for_each_i2cdev(i3cbus, desc) { + switch (desc->boardinfo->lvr & I3C_LVR_I2C_INDEX_MASK) { + case I3C_LVR_I2C_INDEX(0): + if (i3cbus->mode < I3C_BUS_MODE_MIXED_FAST) + i3cbus->mode = I3C_BUS_MODE_MIXED_FAST; + break; + + case I3C_LVR_I2C_INDEX(1): + case I3C_LVR_I2C_INDEX(2): + if (i3cbus->mode < I3C_BUS_MODE_MIXED_SLOW) + i3cbus->mode = I3C_BUS_MODE_MIXED_SLOW; + break; + + default: + return -EINVAL; + } + } + + if (!i3cbus->scl_rate.i3c) + i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; + + if (!i3cbus->scl_rate.i2c) { + if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW) + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; + else + i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE; + } + + /* + * I3C/I2C frequency may have been overridden, check that user-provided + * values are not exceeding max possible frequency. + */ + if (i3cbus->scl_rate.i3c > I3C_BUS_MAX_I3C_SCL_RATE || + i3cbus->scl_rate.i2c > I3C_BUS_I2C_FM_PLUS_SCL_RATE) { + return -EINVAL; + } + + dev_set_name(&i3cbus->dev, "i3c-%d", i3cbus->id); + + return device_add(&i3cbus->dev); +} + +static int __init i3c_init(void) +{ + return bus_register(&i3c_bus_type); +} +subsys_initcall(i3c_init); + +static void __exit i3c_exit(void) +{ + idr_destroy(&i3c_bus_idr); + bus_unregister(&i3c_bus_type); +} +module_exit(i3c_exit); + +MODULE_AUTHOR("Boris Brezillon <boris.brezillon@bootlin.com>"); +MODULE_DESCRIPTION("I3C core"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c new file mode 100644 index 000000000000..69cc040c3a1c --- /dev/null +++ b/drivers/i3c/device.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#include <linux/atomic.h> +#include <linux/bug.h> +#include <linux/completion.h> +#include <linux/device.h> +#include <linux/mutex.h> +#include <linux/slab.h> + +#include "internals.h" + +/** + * i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a + * specific device + * + * @dev: device with which the transfers should be done + * @xfers: array of transfers + * @nxfers: number of transfers + * + * Initiate one or several private SDR transfers with @dev. + * + * This function can sleep and thus cannot be called in atomic context. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_do_priv_xfers(struct i3c_device *dev, + struct i3c_priv_xfer *xfers, + int nxfers) +{ + int ret, i; + + if (nxfers < 1) + return 0; + + for (i = 0; i < nxfers; i++) { + if (!xfers[i].len || !xfers[i].data.in) + return -EINVAL; + } + + i3c_bus_normaluse_lock(dev->bus); + ret = i3c_dev_do_priv_xfers_locked(dev->desc, xfers, nxfers); + i3c_bus_normaluse_unlock(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers); + +/** + * i3c_device_get_info() - get I3C device information + * + * @dev: device we want information on + * @info: the information object to fill in + * + * Retrieve I3C dev info. + */ +void i3c_device_get_info(struct i3c_device *dev, + struct i3c_device_info *info) +{ + if (!info) + return; + + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) + *info = dev->desc->info; + i3c_bus_normaluse_unlock(dev->bus); +} +EXPORT_SYMBOL_GPL(i3c_device_get_info); + +/** + * i3c_device_disable_ibi() - Disable IBIs coming from a specific device + * @dev: device on which IBIs should be disabled + * + * This function disable IBIs coming from a specific device and wait for + * all pending IBIs to be processed. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_disable_ibi(struct i3c_device *dev) +{ + int ret = -ENOENT; + + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + ret = i3c_dev_disable_ibi_locked(dev->desc); + mutex_unlock(&dev->desc->ibi_lock); + } + i3c_bus_normaluse_unlock(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_disable_ibi); + +/** + * i3c_device_enable_ibi() - Enable IBIs coming from a specific device + * @dev: device on which IBIs should be enabled + * + * This function enable IBIs coming from a specific device and wait for + * all pending IBIs to be processed. This should be called on a device + * where i3c_device_request_ibi() has succeeded. + * + * Note that IBIs from this device might be received before this function + * returns to its caller. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_enable_ibi(struct i3c_device *dev) +{ + int ret = -ENOENT; + + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + ret = i3c_dev_enable_ibi_locked(dev->desc); + mutex_unlock(&dev->desc->ibi_lock); + } + i3c_bus_normaluse_unlock(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_enable_ibi); + +/** + * i3c_device_request_ibi() - Request an IBI + * @dev: device for which we should enable IBIs + * @req: setup requested for this IBI + * + * This function is responsible for pre-allocating all resources needed to + * process IBIs coming from @dev. When this function returns, the IBI is not + * enabled until i3c_device_enable_ibi() is called. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_request_ibi(struct i3c_device *dev, + const struct i3c_ibi_setup *req) +{ + int ret = -ENOENT; + + if (!req->handler || !req->num_slots) + return -EINVAL; + + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + ret = i3c_dev_request_ibi_locked(dev->desc, req); + mutex_unlock(&dev->desc->ibi_lock); + } + i3c_bus_normaluse_unlock(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_request_ibi); + +/** + * i3c_device_free_ibi() - Free all resources needed for IBI handling + * @dev: device on which you want to release IBI resources + * + * This function is responsible for de-allocating resources previously + * allocated by i3c_device_request_ibi(). It should be called after disabling + * IBIs with i3c_device_disable_ibi(). + */ +void i3c_device_free_ibi(struct i3c_device *dev) +{ + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + i3c_dev_free_ibi_locked(dev->desc); + mutex_unlock(&dev->desc->ibi_lock); + } + i3c_bus_normaluse_unlock(dev->bus); +} +EXPORT_SYMBOL_GPL(i3c_device_free_ibi); + +/** + * i3cdev_to_dev() - Returns the device embedded in @i3cdev + * @i3cdev: I3C device + * + * Return: a pointer to a device object. + */ +struct device *i3cdev_to_dev(struct i3c_device *i3cdev) +{ + return &i3cdev->dev; +} +EXPORT_SYMBOL_GPL(i3cdev_to_dev); + +/** + * dev_to_i3cdev() - Returns the I3C device containing @dev + * @dev: device object + * + * Return: a pointer to an I3C device object. + */ +struct i3c_device *dev_to_i3cdev(struct device *dev) +{ + return container_of(dev, struct i3c_device, dev); +} +EXPORT_SYMBOL_GPL(dev_to_i3cdev); + +/** + * i3c_driver_register_with_owner() - register an I3C device driver + * + * @drv: driver to register + * @owner: module that owns this driver + * + * Register @drv to the core. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_driver_register_with_owner(struct i3c_driver *drv, struct module *owner) +{ + drv->driver.owner = owner; + drv->driver.bus = &i3c_bus_type; + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(i3c_driver_register_with_owner); + +/** + * i3c_driver_unregister() - unregister an I3C device driver + * + * @drv: driver to unregister + * + * Unregister @drv. + */ +void i3c_driver_unregister(struct i3c_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(i3c_driver_unregister); diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h new file mode 100644 index 000000000000..ced88435466f --- /dev/null +++ b/drivers/i3c/internals.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#ifndef I3C_INTERNALS_H +#define I3C_INTERNALS_H + +#include <linux/i3c/master.h> + +extern struct bus_type i3c_bus_type; +extern const struct device_type i3c_master_type; +extern const struct device_type i3c_device_type; + +void i3c_bus_unref(struct i3c_bus *bus); +struct i3c_bus *i3c_bus_create(struct device *parent); +void i3c_bus_unregister(struct i3c_bus *bus); +int i3c_bus_register(struct i3c_bus *i3cbus); +int i3c_bus_get_free_addr(struct i3c_bus *bus, u8 start_addr); +bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr); +void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr, + enum i3c_addr_slot_status status); +enum i3c_addr_slot_status i3c_bus_get_addr_slot_status(struct i3c_bus *bus, + u16 addr); + +int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev, + struct i3c_priv_xfer *xfers, + int nxfers); +int i3c_dev_disable_ibi_locked(struct i3c_dev_desc *dev); +int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev); +int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev, + const struct i3c_ibi_setup *req); +void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev); +#endif /* I3C_INTERNAL_H */ diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c new file mode 100644 index 000000000000..d04e9ff9c850 --- /dev/null +++ b/drivers/i3c/master.c @@ -0,0 +1,2058 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#include <linux/atomic.h> +#include <linux/bug.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> + +#include "internals.h" + +static struct i3c_master_controller * +i2c_adapter_to_i3c_master(struct i2c_adapter *adap) +{ + return container_of(adap, struct i3c_master_controller, i2c); +} + +static struct i2c_adapter * +i3c_master_to_i2c_adapter(struct i3c_master_controller *master) +{ + return &master->i2c; +} + +static void i3c_master_free_i2c_dev(struct i2c_dev_desc *dev) +{ + kfree(dev); +} + +static struct i2c_dev_desc * +i3c_master_alloc_i2c_dev(struct i3c_master_controller *master, + const struct i2c_dev_boardinfo *boardinfo) +{ + struct i2c_dev_desc *dev; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + dev->common.master = master; + dev->boardinfo = boardinfo; + + return dev; +} + +static int i3c_master_send_ccc_cmd_locked(struct i3c_master_controller *master, + struct i3c_ccc_cmd *cmd) +{ + int ret; + + if (!cmd || !master) + return -EINVAL; + + if (WARN_ON(master->init_done && + !rwsem_is_locked(&master->bus->lock))) + return -EINVAL; + + if (!master->ops->send_ccc_cmd) + return -ENOTSUPP; + + if ((cmd->id & I3C_CCC_DIRECT) && (!cmd->dests || !cmd->ndests)) + return -EINVAL; + + if (master->ops->supports_ccc_cmd && + !master->ops->supports_ccc_cmd(master, cmd)) + return -ENOTSUPP; + + ret = master->ops->send_ccc_cmd(master, cmd); + if (ret) { + if (cmd->err != I3C_ERROR_UNKNOWN) + return cmd->err; + + return ret; + } + + return 0; +} + +static struct i2c_dev_desc * +i3c_master_find_i2c_dev_by_addr(const struct i3c_master_controller *master, + u16 addr) +{ + struct i2c_dev_desc *dev; + + i3c_bus_for_each_i2cdev(master->bus, dev) { + if (dev->boardinfo->base.addr == addr) + return dev; + } + + return NULL; +} + +/** + * i3c_master_get_free_addr() - get a free address on the bus + * @master: I3C master object + * @start_addr: where to start searching + * + * This function must be called with the bus lock held in write mode. + * + * Return: the first free address starting at @start_addr (included) or -ENOMEM + * if there's no more address available. + */ +int i3c_master_get_free_addr(struct i3c_master_controller *master, + u8 start_addr) +{ + return i3c_bus_get_free_addr(master->bus, start_addr); +} +EXPORT_SYMBOL_GPL(i3c_master_get_free_addr); + +static void i3c_device_release(struct device *dev) +{ + struct i3c_device *i3cdev = dev_to_i3cdev(dev); + + WARN_ON(i3cdev->desc); + + of_node_put(i3cdev->dev.of_node); + kfree(i3cdev); +} + +static void i3c_master_free_i3c_dev(struct i3c_dev_desc *dev) +{ + kfree(dev); +} + +static struct i3c_dev_desc * +i3c_master_alloc_i3c_dev(struct i3c_master_controller *master, + const struct i3c_device_info *info) +{ + struct i3c_dev_desc *dev; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + dev->common.master = master; + dev->info = *info; + mutex_init(&dev->ibi_lock); + + return dev; +} + +static int i3c_master_rstdaa_locked(struct i3c_master_controller *master, + u8 addr) +{ + struct i3c_ccc_cmd_dest dest = { }; + struct i3c_ccc_cmd cmd = { }; + enum i3c_addr_slot_status addrstat; + + if (!master) + return -EINVAL; + + addrstat = i3c_bus_get_addr_slot_status(master->bus, addr); + if (addr != I3C_BROADCAST_ADDR && addrstat != I3C_ADDR_SLOT_I3C_DEV) + return -EINVAL; + + dest.addr = addr; + cmd.dests = &dest; + cmd.ndests = 1; + cmd.rnw = false; + cmd.id = I3C_CCC_RSTDAA(addr == I3C_BROADCAST_ADDR); + + return i3c_master_send_ccc_cmd_locked(master, &cmd); +} + +/** + * i3c_master_entdaa_locked() - start a DAA (Dynamic Address Assignment) + * procedure + * @master: master used to send frames on the bus + * + * Send a ENTDAA CCC command to start a DAA procedure. + * + * Note that this function only sends the ENTDAA CCC command, all the logic + * behind dynamic address assignment has to be handled in the I3C master + * driver. + * + * This function must be called with the bus lock held in write mode. + * + * Return: 0 in case of success, a positive I3C error code if the error is + * one of the official Mx error codes, and a negative error code otherwise. + */ +int i3c_master_entdaa_locked(struct i3c_master_controller *master) +{ + struct i3c_ccc_cmd_dest dest = { }; + struct i3c_ccc_cmd cmd = { }; + + dest.addr = I3C_BROADCAST_ADDR; + cmd.dests = &dest; + cmd.ndests = 1; + cmd.rnw = false; + cmd.id = I3C_CCC_ENTDAA; + + return i3c_master_send_ccc_cmd_locked(master, &cmd); +} +EXPORT_SYMBOL_GPL(i3c_master_entdaa_locked); + +/** + * i3c_master_disec_locked() - send a DISEC CCC command + * @master: master used to send frames on the bus + * @addr: a valid I3C slave address or %I3C_BROADCAST_ADDR + * @evts: events to disable + * + * Send a DISEC CCC command to disable some or all events coming from a + * specific slave, or all devices if @addr is %I3C_BROADCAST_ADDR. + * + * This function must be called with the bus lock held in write mode. + * + * Return: 0 in case of success, a positive I3C error code if the error is + * one of the official Mx error codes, and a negative error code otherwise. + */ +int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr, + u8 evts) +{ + struct i3c_ccc_events events = { + .events = evts, + }; + struct i3c_ccc_cmd_dest dest = { + .addr = addr, + .payload.len = sizeof(events), + .payload.data = &events, + }; + struct i3c_ccc_cmd cmd = { + .id = I3C_CCC_DISEC(addr == I3C_BROADCAST_ADDR), + .dests = &dest, + .ndests = 1, + }; + + return i3c_master_send_ccc_cmd_locked(master, &cmd); +} +EXPORT_SYMBOL_GPL(i3c_master_disec_locked); + +/** + * i3c_master_enec_locked() - send an ENEC CCC command + * @master: master used to send frames on the bus + * @addr: a valid I3C slave address or %I3C_BROADCAST_ADDR + * @evts: events to disable + * + * Sends an ENEC CCC command to enable some or all events coming from a + * specific slave, or all devices if @addr is %I3C_BROADCAST_ADDR. + * + * This function must be called with the bus lock held in write mode. + * + * Return: 0 in case of success, a positive I3C error code if the error is + * one of the official Mx error codes, and a negative error code otherwise. + */ +int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr, + u8 evts) +{ + struct i3c_ccc_events events = { + .events = evts, + }; + struct i3c_ccc_cmd_dest dest = { + .addr = addr, + .payload.len = sizeof(events), + .payload.data = &events, + }; + struct i3c_ccc_cmd cmd = { + .id = I3C_CCC_ENEC(addr == I3C_BROADCAST_ADDR), + .dests = &dest, + .ndests = 1, + }; + + return i3c_master_send_ccc_cmd_locked(master, &cmd); +} +EXPORT_SYMBOL_GPL(i3c_master_enec_locked); + +/** + * i3c_master_defslvs_locked() - send a DEFSLVS CCC command + * @master: master used to send frames on the bus + * + * Send a DEFSLVS CCC command containing all the devices known to the @master. + * This is useful when you have secondary masters on the bus to propagate + * device information. + * + * This should be called after all I3C devices have been discovered (in other + * words, after the DAA procedure has finished) and instantiated in + * &i3c_master_controller_ops->bus_init(). + * It should also be called if a master ACKed an Hot-Join request and assigned + * a dynamic address to the device joining the bus. + * + * This function must be called with the bus lock held in write mode. + * + * Return: 0 in case of success, a positive I3C error code if the error is + * one of the official Mx error codes, and a negative error code otherwise. + */ +int i3c_master_defslvs_locked(struct i3c_master_controller *master) +{ + struct i3c_ccc_cmd_dest dest = { + .addr = I3C_BROADCAST_ADDR, + }; + struct i3c_ccc_cmd cmd = { + .id = I3C_CCC_DEFSLVS, + .dests = &dest, + .ndests = 1, + }; + struct i3c_ccc_defslvs *defslvs; + struct i3c_ccc_dev_desc *desc; + struct i3c_dev_desc *i3cdev; + struct i2c_dev_desc *i2cdev; + struct i3c_bus *bus; + bool send = false; + int ndevs = 0, ret; + + if (!master) + return -EINVAL; + + bus = i3c_master_get_bus(master); + i3c_bus_for_each_i3cdev(bus, i3cdev) { + ndevs++; + + if (i3cdev == master->this) + continue; + + if (I3C_BCR_DEVICE_ROLE(i3cdev->info.bcr) == + I3C_BCR_I3C_MASTER) + send = true; + } + + /* No other master on the bus, skip DEFSLVS. */ + if (!send) + return 0; + + i3c_bus_for_each_i2cdev(bus, i2cdev) + ndevs++; + + dest.payload.len = sizeof(*defslvs) + + ((ndevs - 1) * sizeof(struct i3c_ccc_dev_desc)); + defslvs = kzalloc(dest.payload.len, GFP_KERNEL); + if (!defslvs) + return -ENOMEM; + + dest.payload.data = defslvs; + + defslvs->count = ndevs; + defslvs->master.bcr = master->this->info.bcr; + defslvs->master.dcr = master->this->info.dcr; + defslvs->master.dyn_addr = master->this->info.dyn_addr << 1; + defslvs->master.static_addr = I3C_BROADCAST_ADDR << 1; + + desc = defslvs->slaves; + i3c_bus_for_each_i2cdev(bus, i2cdev) { + desc->lvr = i2cdev->boardinfo->lvr; + desc->static_addr = i2cdev->boardinfo->base.addr << 1; + desc++; + } + + i3c_bus_for_each_i3cdev(bus, i3cdev) { + /* Skip the I3C dev representing this master. */ + if (i3cdev == master->this) + continue; + + desc->bcr = i3cdev->info.bcr; + desc->dcr = i3cdev->info.dcr; + desc->dyn_addr = i3cdev->info.dyn_addr << 1; + desc->static_addr = i3cdev->info.static_addr << 1; + desc++; + } + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + kfree(defslvs); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_master_defslvs_locked); + +static int i3c_master_setdasa_locked(struct i3c_master_controller *master, + u8 static_addr, u8 dyn_addr) +{ + struct i3c_ccc_setda setda = { + .addr = dyn_addr << 1, + }; + struct i3c_ccc_cmd_dest dest = { + .addr = static_addr, + .payload.len = sizeof(setda), + .payload.data = &setda, + }; + struct i3c_ccc_cmd cmd = { + .rnw = false, + .id = I3C_CCC_SETDASA, + .dests = &dest, + .ndests = 1, + }; + + if (!dyn_addr || !static_addr) + return -EINVAL; + + return i3c_master_send_ccc_cmd_locked(master, &cmd); +} + +static int i3c_master_setnewda_locked(struct i3c_master_controller *master, + u8 oldaddr, u8 newaddr) +{ + struct i3c_ccc_setda setda = { + .addr = newaddr << 1, + }; + struct i3c_ccc_cmd_dest dest = { + .addr = oldaddr, + .payload.len = sizeof(setda), + .payload.data = &setda, + }; + struct i3c_ccc_cmd cmd = { + .rnw = false, + .id = I3C_CCC_SETNEWDA, + .dests = &dest, + .ndests = 1, + }; + + if (!oldaddr || !newaddr) + return -EINVAL; + + return i3c_master_send_ccc_cmd_locked(master, &cmd); +} + +static int i3c_master_getmrl_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_mrl mrl; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(mrl), + .payload.data = &mrl, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETMRL, + .dests = &dest, + .ndests = 1, + }; + int ret; + + /* + * When the device does not have IBI payload GETMRL only returns 2 + * bytes of data. + */ + if (!(info->bcr & I3C_BCR_IBI_PAYLOAD)) + dest.payload.len -= 1; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + if (dest.payload.len != sizeof(mrl)) + return -EIO; + + info->max_read_len = be16_to_cpu(mrl.read_len); + + if (info->bcr & I3C_BCR_IBI_PAYLOAD) + info->max_ibi_len = mrl.ibi_len; + + return 0; +} + +static int i3c_master_getmwl_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_mwl mwl; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(mwl), + .payload.data = &mwl, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETMWL, + .dests = &dest, + .ndests = 1, + }; + int ret; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + if (dest.payload.len != sizeof(mwl)) + return -EIO; + + info->max_write_len = be16_to_cpu(mwl.len); + + return 0; +} + +static int i3c_master_getmxds_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_getmxds getmaxds; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(getmaxds), + .payload.data = &getmaxds, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETMXDS, + .dests = &dest, + .ndests = 1, + }; + int ret; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + if (dest.payload.len != 2 && dest.payload.len != 5) + return -EIO; + + info->max_read_ds = getmaxds.maxrd; + info->max_read_ds = getmaxds.maxwr; + if (dest.payload.len == 5) + info->max_read_turnaround = getmaxds.maxrdturn[0] | + ((u32)getmaxds.maxrdturn[1] << 8) | + ((u32)getmaxds.maxrdturn[2] << 16); + + return 0; +} + +static int i3c_master_gethdrcap_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_gethdrcap gethdrcap; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(gethdrcap), + .payload.data = &gethdrcap, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETHDRCAP, + .dests = &dest, + .ndests = 1, + }; + int ret; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + if (dest.payload.len != 1) + return -EIO; + + info->hdr_cap = gethdrcap.modes; + + return 0; +} + +static int i3c_master_getpid_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_getpid getpid; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(struct i3c_ccc_getpid), + .payload.data = &getpid, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETPID, + .dests = &dest, + .ndests = 1, + }; + int ret, i; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + info->pid = 0; + for (i = 0; i < sizeof(getpid.pid); i++) { + int sft = (sizeof(getpid.pid) - i - 1) * 8; + + info->pid |= (u64)getpid.pid[i] << sft; + } + + return 0; +} + +static int i3c_master_getbcr_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_getbcr getbcr; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(struct i3c_ccc_getbcr), + .payload.data = &getbcr, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETBCR, + .dests = &dest, + .ndests = 1, + }; + int ret; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + info->bcr = getbcr.bcr; + + return 0; +} + +static int i3c_master_getdcr_locked(struct i3c_master_controller *master, + struct i3c_device_info *info) +{ + struct i3c_ccc_getdcr getdcr; + struct i3c_ccc_cmd_dest dest = { + .addr = info->dyn_addr, + .payload.len = sizeof(struct i3c_ccc_getdcr), + .payload.data = &getdcr, + }; + struct i3c_ccc_cmd cmd = { + .rnw = true, + .id = I3C_CCC_GETDCR, + .dests = &dest, + .ndests = 1, + }; + int ret; + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + return ret; + + info->dcr = getdcr.dcr; + + return 0; +} + +static int i3c_master_retrieve_dev_info(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + enum i3c_addr_slot_status slot_status; + int ret; + + if (!dev->info.dyn_addr) + return -EINVAL; + + slot_status = i3c_bus_get_addr_slot_status(master->bus, + dev->info.dyn_addr); + if (slot_status == I3C_ADDR_SLOT_RSVD || + slot_status == I3C_ADDR_SLOT_I2C_DEV) + return -EINVAL; + + ret = i3c_master_getpid_locked(master, &dev->info); + if (ret) + return ret; + + ret = i3c_master_getbcr_locked(master, &dev->info); + if (ret) + return ret; + + ret = i3c_master_getdcr_locked(master, &dev->info); + if (ret) + return ret; + + if (dev->info.bcr & I3C_BCR_MAX_DATA_SPEED_LIM) { + ret = i3c_master_getmxds_locked(master, &dev->info); + if (ret) + return ret; + } + + if (dev->info.bcr & I3C_BCR_IBI_PAYLOAD) + dev->info.max_ibi_len = 1; + + i3c_master_getmrl_locked(master, &dev->info); + i3c_master_getmwl_locked(master, &dev->info); + + if (dev->info.bcr & I3C_BCR_HDR_CAP) { + ret = i3c_master_gethdrcap_locked(master, &dev->info); + if (ret) + return ret; + } + + return 0; +} + +static void i3c_master_put_i3c_addrs(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + + if (dev->info.static_addr) + i3c_bus_set_addr_slot_status(master->bus, + dev->info.static_addr, + I3C_ADDR_SLOT_FREE); + + if (dev->info.dyn_addr) + i3c_bus_set_addr_slot_status(master->bus, dev->info.dyn_addr, + I3C_ADDR_SLOT_FREE); + + if (dev->boardinfo && dev->boardinfo->init_dyn_addr) + i3c_bus_set_addr_slot_status(master->bus, dev->info.dyn_addr, + I3C_ADDR_SLOT_FREE); +} + +static int i3c_master_get_i3c_addrs(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + enum i3c_addr_slot_status status; + + if (!dev->info.static_addr && !dev->info.dyn_addr) + return 0; + + if (dev->info.static_addr) { + status = i3c_bus_get_addr_slot_status(master->bus, + dev->info.static_addr); + if (status != I3C_ADDR_SLOT_FREE) + return -EBUSY; + + i3c_bus_set_addr_slot_status(master->bus, + dev->info.static_addr, + I3C_ADDR_SLOT_I3C_DEV); + } + + /* + * ->init_dyn_addr should have been reserved before that, so, if we're + * trying to apply a pre-reserved dynamic address, we should not try + * to reserve the address slot a second time. + */ + if (dev->info.dyn_addr && + (!dev->boardinfo || + dev->boardinfo->init_dyn_addr != dev->info.dyn_addr)) { + status = i3c_bus_get_addr_slot_status(master->bus, + dev->info.dyn_addr); + if (status != I3C_ADDR_SLOT_FREE) + goto err_release_static_addr; + + i3c_bus_set_addr_slot_status(master->bus, dev->info.dyn_addr, + I3C_ADDR_SLOT_I3C_DEV); + } + + return 0; + +err_release_static_addr: + if (dev->info.static_addr) + i3c_bus_set_addr_slot_status(master->bus, + dev->info.static_addr, + I3C_ADDR_SLOT_FREE); + + return -EBUSY; +} + +static int i3c_master_attach_i3c_dev(struct i3c_master_controller *master, + struct i3c_dev_desc *dev) +{ + int ret; + + /* + * We don't attach devices to the controller until they are + * addressable on the bus. + */ + if (!dev->info.static_addr && !dev->info.dyn_addr) + return 0; + + ret = i3c_master_get_i3c_addrs(dev); + if (ret) + return ret; + + /* Do not attach the master device itself. */ + if (master->this != dev && master->ops->attach_i3c_dev) { + ret = master->ops->attach_i3c_dev(dev); + if (ret) { + i3c_master_put_i3c_addrs(dev); + return ret; + } + } + + list_add_tail(&dev->common.node, &master->bus->devs.i3c); + + return 0; +} + +static int i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev, + u8 old_dyn_addr) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + enum i3c_addr_slot_status status; + int ret; + + if (dev->info.dyn_addr != old_dyn_addr) { + status = i3c_bus_get_addr_slot_status(master->bus, + dev->info.dyn_addr); + if (status != I3C_ADDR_SLOT_FREE) + return -EBUSY; + i3c_bus_set_addr_slot_status(master->bus, + dev->info.dyn_addr, + I3C_ADDR_SLOT_I3C_DEV); + } + + if (master->ops->reattach_i3c_dev) { + ret = master->ops->reattach_i3c_dev(dev, old_dyn_addr); + if (ret) { + i3c_master_put_i3c_addrs(dev); + return ret; + } + } + + return 0; +} + +static void i3c_master_detach_i3c_dev(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + + /* Do not detach the master device itself. */ + if (master->this != dev && master->ops->detach_i3c_dev) + master->ops->detach_i3c_dev(dev); + + i3c_master_put_i3c_addrs(dev); + list_del(&dev->common.node); +} + +static int i3c_master_attach_i2c_dev(struct i3c_master_controller *master, + struct i2c_dev_desc *dev) +{ + int ret; + + if (master->ops->attach_i2c_dev) { + ret = master->ops->attach_i2c_dev(dev); + if (ret) + return ret; + } + + list_add_tail(&dev->common.node, &master->bus->devs.i2c); + + return 0; +} + +static void i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev) +{ + struct i3c_master_controller *master = i2c_dev_get_master(dev); + + list_del(&dev->common.node); + + if (master->ops->detach_i2c_dev) + master->ops->detach_i2c_dev(dev); +} + +static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + struct i3c_device_info info; + int ret; + + if (!dev->boardinfo || !dev->boardinfo->init_dyn_addr || + !dev->boardinfo->static_addr) + return; + + ret = i3c_master_setdasa_locked(master, dev->info.static_addr, + dev->boardinfo->init_dyn_addr); + if (ret) + return; + + dev->info.dyn_addr = dev->boardinfo->init_dyn_addr; + ret = i3c_master_reattach_i3c_dev(dev, 0); + if (ret) + return; + + ret = i3c_master_retrieve_dev_info(dev); + if (ret) + goto err_rstdaa; + + dev->info = info; + + return; + +err_rstdaa: + i3c_master_rstdaa_locked(master, dev->boardinfo->init_dyn_addr); +} + +static void +i3c_master_register_new_i3c_devs(struct i3c_master_controller *master) +{ + struct i3c_dev_desc *desc; + int ret; + + if (!master->init_done) + return; + + i3c_bus_for_each_i3cdev(master->bus, desc) { + if (desc->dev || !desc->info.dyn_addr) + continue; + + desc->dev = kzalloc(sizeof(*desc->dev), GFP_KERNEL); + if (!desc->dev) + continue; + + desc->dev->bus = master->bus; + desc->dev->desc = desc; + desc->dev->dev.parent = &master->bus->dev; + if (desc == master->this) + desc->dev->dev.type = &i3c_master_type; + else + desc->dev->dev.type = &i3c_device_type; + desc->dev->dev.bus = &i3c_bus_type; + desc->dev->dev.release = i3c_device_release; + dev_set_name(&desc->dev->dev, "%d-%llx", master->bus->id, + desc->info.pid); + + if (desc->boardinfo) + desc->dev->dev.of_node = desc->boardinfo->of_node; + + pr_info("%s:%i\n", __func__, __LINE__); + if (ret) + dev_err(master->parent, + "Failed to add I3C device (err = %d)\n", ret); + } +} + +/** + * i3c_master_do_daa() - do a DAA (Dynamic Address Assignment) + * @master: master doing the DAA + * + * This function is instantiating an I3C device object and adding it to the + * I3C device list. All device information are automatically retrieved using + * standard CCC commands. + * + * The I3C device object is returned in case the master wants to attach + * private data to it using i3c_dev_set_master_data(). + * + * This function must be called with the bus lock held in write mode. + * + * Return: a 0 in case of success, an negative error code otherwise. + */ +int i3c_master_do_daa(struct i3c_master_controller *master) +{ + int ret; + + i3c_bus_maintenance_lock(master->bus); + ret = master->ops->do_daa(master); + i3c_bus_maintenance_unlock(master->bus); + + if (ret) + return ret; + + i3c_bus_normaluse_lock(master->bus); + i3c_master_register_new_i3c_devs(master); + i3c_bus_normaluse_unlock(master->bus); + + return 0; +} +EXPORT_SYMBOL_GPL(i3c_master_do_daa); + +/** + * i3c_master_set_info() - set master device information + * @master: master used to send frames on the bus + * @info: I3C device information + * + * Set master device info. This should be called from + * &i3c_master_controller_ops->bus_init(). + * + * Not all &i3c_device_info fields are meaningful for a master device. + * Here is a list of fields that should be properly filled: + * + * - &i3c_device_info->dyn_addr + * - &i3c_device_info->bcr + * - &i3c_device_info->dcr + * - &i3c_device_info->pid + * - &i3c_device_info->hdr_cap if %I3C_BCR_HDR_CAP bit is set in + * &i3c_device_info->bcr + * + * This function must be called with the bus lock held in maintenance mode. + * + * Return: 0 if @info contains valid information (not every piece of + * information can be checked, but we can at least make sure @info->dyn_addr + * and @info->bcr are correct), -EINVAL otherwise. + */ +int i3c_master_set_info(struct i3c_master_controller *master, + const struct i3c_device_info *info) +{ + struct i3c_dev_desc *i3cdev; + int ret; + + if (!i3c_bus_dev_addr_is_avail(master->bus, info->dyn_addr)) + return -EINVAL; + + if (I3C_BCR_DEVICE_ROLE(info->bcr) == I3C_BCR_I3C_MASTER && + master->secondary) + return -EINVAL; + + if (master->this) + return -EINVAL; + + i3cdev = i3c_master_alloc_i3c_dev(master, info); + if (IS_ERR(i3cdev)) + return PTR_ERR(i3cdev); + + master->this = i3cdev; + master->bus->cur_master = master->this; + + ret = i3c_master_attach_i3c_dev(master, i3cdev); + if (ret) + goto err_free_dev; + + return 0; + +err_free_dev: + i3c_master_free_i3c_dev(i3cdev); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_master_set_info); + +static void i3c_master_detach_free_devs(struct i3c_master_controller *master) +{ + struct i3c_dev_desc *i3cdev, *i3ctmp; + struct i2c_dev_desc *i2cdev, *i2ctmp; + + list_for_each_entry_safe(i3cdev, i3ctmp, &master->bus->devs.i3c, + common.node) { + i3c_master_detach_i3c_dev(i3cdev); + + if (i3cdev->boardinfo && i3cdev->boardinfo->init_dyn_addr) + i3c_bus_set_addr_slot_status(master->bus, + i3cdev->boardinfo->init_dyn_addr, + I3C_ADDR_SLOT_FREE); + + i3c_master_free_i3c_dev(i3cdev); + } + + list_for_each_entry_safe(i2cdev, i2ctmp, &master->bus->devs.i2c, + common.node) { + i3c_master_detach_i2c_dev(i2cdev); + i3c_bus_set_addr_slot_status(master->bus, + i2cdev->boardinfo->base.addr, + I3C_ADDR_SLOT_FREE); + i3c_master_free_i2c_dev(i2cdev); + } +} + +/** + * i3c_master_bus_init() - initialize an I3C bus + * @master: main master initializing the bus + * + * This function is following all initialisation steps described in the I3C + * specification: + * + * 1. Attach I2C and statically defined I3C devs to the master so that the + * master can fill its internal device table appropriately + * + * 2. Call &i3c_master_controller_ops->bus_init() method to initialize + * the master controller. That's usually where the bus mode is selected + * (pure bus or mixed fast/slow bus) + * + * 3. Instruct all devices on the bus to drop their dynamic address. This is + * particularly important when the bus was previously configured by someone + * else (for example the bootloader) + * + * 4. Disable all slave events. + * + * 5. Pre-assign dynamic addresses requested by the FW with SETDASA for I3C + * devices that have a static address + * + * 6. Do a DAA (Dynamic Address Assignment) to assign dynamic addresses to all + * remaining I3C devices + * + * Once this is done, all I3C and I2C devices should be usable. + * + * Return: a 0 in case of success, an negative error code otherwise. + */ +static int i3c_master_bus_init(struct i3c_master_controller *master) +{ + enum i3c_addr_slot_status status; + struct i2c_dev_boardinfo *i2cboardinfo; + struct i3c_dev_boardinfo *i3cboardinfo; + struct i3c_dev_desc *i3cdev; + struct i2c_dev_desc *i2cdev; + int ret; + + /* + * First attach all devices with static definitions provided by the + * FW. + */ + list_for_each_entry(i2cboardinfo, &master->boardinfo.i2c, node) { + status = i3c_bus_get_addr_slot_status(master->bus, + i2cboardinfo->base.addr); + if (status != I3C_ADDR_SLOT_FREE) { + ret = -EBUSY; + goto err_detach_devs; + } + + i3c_bus_set_addr_slot_status(master->bus, + i2cboardinfo->base.addr, + I3C_ADDR_SLOT_I2C_DEV); + + i2cdev = i3c_master_alloc_i2c_dev(master, i2cboardinfo); + if (IS_ERR(i2cdev)) { + ret = PTR_ERR(i2cdev); + goto err_detach_devs; + } + + ret = i3c_master_attach_i2c_dev(master, i2cdev); + if (ret) { + i3c_master_free_i2c_dev(i2cdev); + goto err_detach_devs; + } + } + list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) { + struct i3c_device_info info = { + .static_addr = i3cboardinfo->static_addr, + }; + + if (i3cboardinfo->init_dyn_addr) { + status = i3c_bus_get_addr_slot_status(master->bus, + i3cboardinfo->init_dyn_addr); + if (status != I3C_ADDR_SLOT_FREE) { + ret = -EBUSY; + goto err_detach_devs; + } + } + + i3cdev = i3c_master_alloc_i3c_dev(master, &info); + if (IS_ERR(i3cdev)) { + ret = PTR_ERR(i3cdev); + goto err_detach_devs; + } + + i3cdev->boardinfo = i3cboardinfo; + + ret = i3c_master_attach_i3c_dev(master, i3cdev); + if (ret) { + i3c_master_free_i3c_dev(i3cdev); + goto err_detach_devs; + } + } + + /* + * Now execute the controller specific ->bus_init() routine, which + * might configure its internal logic to match the bus limitations. + */ + ret = master->ops->bus_init(master); + if (ret) + goto err_detach_devs; + + /* + * The master device should have been instantiated in ->bus_init(), + * complain if this was not the case. + */ + if (!master->this) { + dev_err(master->parent, + "master_set_info() was not called in ->bus_init()\n"); + ret = -EINVAL; + goto err_bus_cleanup; + } + + /* + * Reset all dynamic address that may have been assigned before + * (assigned by the bootloader for example). + */ + ret = i3c_master_rstdaa_locked(master, I3C_BROADCAST_ADDR); + if (ret && ret != I3C_ERROR_M2) + goto err_bus_cleanup; + + /* Disable all slave events before starting DAA. */ + ret = i3c_master_disec_locked(master, I3C_BROADCAST_ADDR, + I3C_CCC_EVENT_SIR | I3C_CCC_EVENT_MR | + I3C_CCC_EVENT_HJ); + if (ret && ret != I3C_ERROR_M2) + goto err_bus_cleanup; + + /* + * Pre-assign dynamic address and retrieve device information if + * needed. + */ + i3c_bus_for_each_i3cdev(master->bus, i3cdev) + i3c_master_pre_assign_dyn_addr(i3cdev); + + ret = i3c_master_do_daa(master); + if (ret) + goto err_rstdaa; + + return 0; + +err_rstdaa: + i3c_master_rstdaa_locked(master, I3C_BROADCAST_ADDR); + +err_bus_cleanup: + if (master->ops->bus_cleanup) + master->ops->bus_cleanup(master); + +err_detach_devs: + i3c_master_detach_free_devs(master); + + return ret; +} + +static void i3c_master_bus_cleanup(struct i3c_master_controller *master) +{ + if (master->ops->bus_cleanup) + master->ops->bus_cleanup(master); + + i3c_master_detach_free_devs(master); +} + +static struct i3c_dev_desc * +i3c_master_search_i3c_dev_duplicate(struct i3c_dev_desc *refdev) +{ + struct i3c_master_controller *master = refdev->common.master; + struct i3c_dev_desc *i3cdev; + + i3c_bus_for_each_i3cdev(master->bus, i3cdev) { + if (i3cdev != refdev && i3cdev->info.pid == refdev->info.pid) + return i3cdev; + } + + return NULL; +} + +/** + * i3c_master_add_i3c_dev_locked() - add an I3C slave to the bus + * @master: master used to send frames on the bus + * @addr: I3C slave dynamic address assigned to the device + * + * This function is instantiating an I3C device object and adding it to the + * I3C device list. All device information are automatically retrieved using + * standard CCC commands. + * + * The I3C device object is returned in case the master wants to attach + * private data to it using i3c_dev_set_master_data(). + * + * This function must be called with the bus lock held in write mode. + * + * Return: a 0 in case of success, an negative error code otherwise. + */ +int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master, + u8 addr) +{ + struct i3c_device_info info = { .dyn_addr = addr }; + struct i3c_dev_desc *newdev, *olddev; + u8 old_dyn_addr = addr, expected_dyn_addr; + struct i3c_ibi_setup ibireq = { }; + bool enable_ibi = false; + int ret; + + if (!master) + return -EINVAL; + + newdev = i3c_master_alloc_i3c_dev(master, &info); + if (IS_ERR(newdev)) + return PTR_ERR(newdev); + + ret = i3c_master_attach_i3c_dev(master, newdev); + if (ret) { + ret = PTR_ERR(newdev); + goto err_free_dev; + } + + ret = i3c_master_retrieve_dev_info(newdev); + if (ret) + goto err_free_dev; + + olddev = i3c_master_search_i3c_dev_duplicate(newdev); + if (olddev) { + newdev->boardinfo = olddev->boardinfo; + newdev->info.static_addr = olddev->info.static_addr; + newdev->dev = olddev->dev; + if (newdev->dev) + newdev->dev->desc = newdev; + + /* + * We need to restore the IBI state too, so let's save the + * IBI information and try to restore them after olddev has + * been detached+released and its IBI has been stopped and + * the associated resources have been freed. + */ + mutex_lock(&olddev->ibi_lock); + if (olddev->ibi) { + ibireq.handler = olddev->ibi->handler; + ibireq.max_payload_len = olddev->ibi->max_payload_len; + ibireq.num_slots = olddev->ibi->num_slots; + + if (olddev->ibi->enabled) { + enable_ibi = true; + i3c_dev_disable_ibi_locked(olddev); + } + + i3c_dev_free_ibi_locked(olddev); + } + mutex_unlock(&olddev->ibi_lock); + + old_dyn_addr = olddev->info.dyn_addr; + + i3c_master_detach_i3c_dev(olddev); + i3c_master_free_i3c_dev(olddev); + } + + ret = i3c_master_reattach_i3c_dev(newdev, old_dyn_addr); + if (ret) + goto err_detach_dev; + + /* + * Depending on our previous state, the expected dynamic address might + * differ: + * - if the device already had a dynamic address assigned, let's try to + * re-apply this one + * - if the device did not have a dynamic address and the firmware + * requested a specific address, pick this one + * - in any other case, keep the address automatically assigned by the + * master + */ + if (old_dyn_addr && old_dyn_addr != newdev->info.dyn_addr) + expected_dyn_addr = old_dyn_addr; + else if (newdev->boardinfo && newdev->boardinfo->init_dyn_addr) + expected_dyn_addr = newdev->boardinfo->init_dyn_addr; + else + expected_dyn_addr = newdev->info.dyn_addr; + + if (newdev->info.dyn_addr != expected_dyn_addr) { + /* + * Try to apply the expected dynamic address. If it fails, keep + * the address assigned by the master. + */ + ret = i3c_master_setnewda_locked(master, + newdev->info.dyn_addr, + expected_dyn_addr); + if (!ret) { + old_dyn_addr = newdev->info.dyn_addr; + newdev->info.dyn_addr = expected_dyn_addr; + i3c_master_reattach_i3c_dev(newdev, old_dyn_addr); + } else { + dev_err(master->parent, + "Failed to assign reserved/old address to device %d%llx", + master->bus->id, newdev->info.pid); + } + } + + /* + * Now is time to try to restore the IBI setup. If we're lucky, + * everything works as before, otherwise, all we can do is complain. + * FIXME: maybe we should add callback to inform the driver that it + * should request the IBI again instead of trying to hide that from + * him. + */ + if (ibireq.handler) { + mutex_lock(&newdev->ibi_lock); + ret = i3c_dev_request_ibi_locked(newdev, &ibireq); + if (ret) { + dev_err(master->parent, + "Failed to request IBI on device %d-%llx", + master->bus->id, newdev->info.pid); + } else if (enable_ibi) { + ret = i3c_dev_enable_ibi_locked(newdev); + if (ret) + dev_err(master->parent, + "Failed to re-enable IBI on device %d-%llx", + master->bus->id, newdev->info.pid); + } + mutex_lock(&newdev->ibi_lock); + } + + return 0; + +err_detach_dev: + if (newdev->dev && newdev->dev->desc) + newdev->dev->desc = NULL; + + i3c_master_detach_i3c_dev(newdev); + +err_free_dev: + i3c_master_free_i3c_dev(newdev); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_master_add_i3c_dev_locked); + +#define OF_I3C_REG1_IS_I2C_DEV BIT(31) + +static int +of_i3c_master_add_i2c_boardinfo(struct i3c_master_controller *master, + struct device_node *node, u32 *reg) +{ + struct i2c_dev_boardinfo *boardinfo; + struct device *dev = master->parent; + /* LVR is encoded in the lowest byte of reg[1]. */ + int ret; + + boardinfo = devm_kzalloc(dev, sizeof(*boardinfo), GFP_KERNEL); + if (!boardinfo) + return -ENOMEM; + + ret = of_i2c_get_board_info(dev, node, &boardinfo->base); + if (ret) + return ret; + + boardinfo->lvr = reg[1]; + + if (boardinfo->lvr & I3C_LVR_I2C_FM_MODE) + master->bus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE; + + list_add_tail(&boardinfo->node, &master->boardinfo.i2c); + of_node_get(node); + + return 0; +} + +static int +of_i3c_master_add_i3c_boardinfo(struct i3c_master_controller *master, + struct device_node *node, u32 *reg) +{ + struct i3c_dev_boardinfo *boardinfo; + struct device *dev = master->parent; + struct i3c_device_info info = { }; + enum i3c_addr_slot_status addrstatus; + u32 init_dyn_addr = 0; + + boardinfo = devm_kzalloc(dev, sizeof(*boardinfo), GFP_KERNEL); + if (!boardinfo) + return -ENOMEM; + + if (reg[0]) { + if (reg[0] > I3C_MAX_ADDR) + return -EINVAL; + + addrstatus = i3c_bus_get_addr_slot_status(master->bus, reg[0]); + if (addrstatus != I3C_ADDR_SLOT_FREE) + return -EINVAL; + } + + boardinfo->static_addr = reg[0]; + + if (!of_property_read_u32(node, "assigned-address", &init_dyn_addr)) { + if (init_dyn_addr > I3C_MAX_ADDR) + return -EINVAL; + + addrstatus = i3c_bus_get_addr_slot_status(master->bus, + init_dyn_addr); + if (addrstatus != I3C_ADDR_SLOT_FREE) + return -EINVAL; + } + + boardinfo->pid = ((u64)reg[1] << 32) | reg[2]; + + if ((info.pid & GENMASK_ULL(63, 48)) || + I3C_PID_RND_LOWER_32BITS(info.pid)) + return -EINVAL; + + boardinfo->init_dyn_addr = init_dyn_addr; + boardinfo->of_node = of_node_get(node); + list_add_tail(&boardinfo->node, &master->boardinfo.i3c); + + return 0; +} + +static int of_i3c_master_add_dev(struct i3c_master_controller *master, + struct device_node *node) +{ + u32 reg[3]; + int ret; + + if (!master || !node) + return -EINVAL; + + ret = of_property_read_u32_array(node, "reg", reg, ARRAY_SIZE(reg)); + if (ret) + return ret; + + if (reg[1] & OF_I3C_REG1_IS_I2C_DEV) + ret = of_i3c_master_add_i2c_boardinfo(master, node, reg); + else + ret = of_i3c_master_add_i3c_boardinfo(master, node, reg); + + return ret; +} + +static int of_populate_i3c_bus(struct i3c_master_controller *master) +{ + struct device *dev = &master->bus->dev; + struct device_node *i3cbus_np = dev->of_node; + struct device_node *node; + int ret; + u32 val; + + if (!i3cbus_np) + return 0; + + for_each_available_child_of_node(i3cbus_np, node) { + ret = of_i3c_master_add_dev(master, node); + if (ret) + return ret; + } + + /* + * The user might want to limit I2C and I3C speed in case some devices + * on the bus are not supporting typical rates, or if the bus topology + * prevents it from using max possible rate. + */ + if (!of_property_read_u32(i3cbus_np, "i2c-scl-hz", &val)) + master->bus->scl_rate.i2c = val; + + if (!of_property_read_u32(i3cbus_np, "i3c-scl-hz", &val)) + master->bus->scl_rate.i3c = val; + + return 0; +} + +static int i3c_master_i2c_adapter_xfer(struct i2c_adapter *adap, + struct i2c_msg *xfers, int nxfers) +{ + struct i3c_master_controller *master = i2c_adapter_to_i3c_master(adap); + struct i2c_dev_desc *dev; + int i, ret; + u16 addr; + + if (!xfers || !master || nxfers <= 0) + return -EINVAL; + + if (!master->ops->i2c_xfers) + return -ENOTSUPP; + + /* Doing transfers to different devices is not supported. */ + addr = xfers[0].addr; + for (i = 1; i < nxfers; i++) { + if (addr != xfers[i].addr) + return -ENOTSUPP; + } + + i3c_bus_normaluse_lock(master->bus); + dev = i3c_master_find_i2c_dev_by_addr(master, addr); + if (!dev) + ret = -ENOENT; + else + ret = master->ops->i2c_xfers(dev, xfers, nxfers); + i3c_bus_normaluse_unlock(master->bus); + + return ret ? ret : nxfers; +} + +static u32 i3c_master_i2c_functionalities(struct i2c_adapter *adap) +{ + struct i3c_master_controller *master = i2c_adapter_to_i3c_master(adap); + + return master->ops->i2c_funcs(master); +} + +static const struct i2c_algorithm i3c_master_i2c_algo = { + .master_xfer = i3c_master_i2c_adapter_xfer, + .functionality = i3c_master_i2c_functionalities, +}; + +static int i3c_master_i2c_adapter_init(struct i3c_master_controller *master) +{ + struct i2c_adapter *adap = i3c_master_to_i2c_adapter(master); + struct i2c_dev_desc *i2cdev; + int ret; + + adap->dev.parent = master->parent; + adap->owner = master->parent->driver->owner; + adap->algo = &i3c_master_i2c_algo; + strncpy(adap->name, dev_name(master->parent), sizeof(adap->name)); + + /* FIXME: Should we allow i3c masters to override these values? */ + adap->timeout = 1000; + adap->retries = 3; + + ret = i2c_add_adapter(adap); + if (ret) + return ret; + + /* + * We silently ignore failures here. The bus should keep working + * correctly even if one or more i2c devices are not registered. + */ + i3c_bus_for_each_i2cdev(master->bus, i2cdev) + i2cdev->dev = i2c_new_device(adap, &i2cdev->boardinfo->base); + + return 0; +} + +static void i3c_master_i2c_adapter_cleanup(struct i3c_master_controller *master) +{ + struct i2c_dev_desc *i2cdev; + + i2c_del_adapter(&master->i2c); + + i3c_bus_for_each_i2cdev(master->bus, i2cdev) + i2cdev->dev = NULL; +} + +static void i3c_master_unregister_i3c_devs(struct i3c_master_controller *master) +{ + struct i3c_dev_desc *i3cdev; + + i3c_bus_for_each_i3cdev(master->bus, i3cdev) { + if (!i3cdev->dev) + continue; + + i3cdev->dev->desc = NULL; + if (device_is_registered(&i3cdev->dev->dev)) + device_unregister(&i3cdev->dev->dev); + else + put_device(&i3cdev->dev->dev); + i3cdev->dev = NULL; + } +} + +/** + * i3c_master_queue_ibi() - Queue an IBI + * @dev: the device this IBI is coming from + * @slot: the IBI slot used to store the payload + * + * Queue an IBI to the controller workqueue. The IBI handler attached to + * the dev will be called from a workqueue context. + */ +void i3c_master_queue_ibi(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot) +{ + atomic_inc(&dev->ibi->pending_ibis); + queue_work(dev->common.master->wq, &slot->work); +} +EXPORT_SYMBOL_GPL(i3c_master_queue_ibi); + +static void i3c_master_handle_ibi(struct work_struct *work) +{ + struct i3c_ibi_slot *slot = container_of(work, struct i3c_ibi_slot, + work); + struct i3c_dev_desc *dev = slot->dev; + struct i3c_master_controller *master = i3c_dev_get_master(dev); + struct i3c_ibi_payload payload; + + payload.data = slot->data; + payload.len = slot->len; + + if (dev->dev) + dev->ibi->handler(dev->dev, &payload); + + master->ops->recycle_ibi_slot(dev, slot); + if (atomic_dec_and_test(&dev->ibi->pending_ibis)) + complete(&dev->ibi->all_ibis_handled); +} + +static void i3c_master_init_ibi_slot(struct i3c_dev_desc *dev, + struct i3c_ibi_slot *slot) +{ + slot->dev = dev; + INIT_WORK(&slot->work, i3c_master_handle_ibi); +} + +struct i3c_generic_ibi_slot { + struct list_head node; + struct i3c_ibi_slot base; +}; + +struct i3c_generic_ibi_pool { + spinlock_t lock; + unsigned int num_slots; + struct i3c_generic_ibi_slot *slots; + void *payload_buf; + struct list_head free_slots; + struct list_head pending; +}; + +/** + * i3c_generic_ibi_free_pool() - Free a generic IBI pool + * @pool: the IBI pool to free + * + * Free all IBI slots allated by a generic IBI pool. + */ +void i3c_generic_ibi_free_pool(struct i3c_generic_ibi_pool *pool) +{ + struct i3c_generic_ibi_slot *slot; + unsigned int nslots = 0; + + while (!list_empty(&pool->free_slots)) { + slot = list_first_entry(&pool->free_slots, + struct i3c_generic_ibi_slot, node); + list_del(&slot->node); + nslots++; + } + + /* + * If the number of freed slots is not equal to the number of allocated + * slots we have a leak somewhere. + */ + WARN_ON(nslots != pool->num_slots); + + kfree(pool->payload_buf); + kfree(pool->slots); + kfree(pool); +} +EXPORT_SYMBOL_GPL(i3c_generic_ibi_free_pool); + +/** + * i3c_generic_ibi_alloc_pool() - Create a generic IBI pool + * @dev: the device this pool will be used for + * @req: IBI setup request describing what the device driver expects + * + * Create a generic IBI pool based on the information provided in @req. + * + * Return: a valid IBI pool in case of success, an ERR_PTR() otherwise. + */ +struct i3c_generic_ibi_pool * +i3c_generic_ibi_alloc_pool(struct i3c_dev_desc *dev, + const struct i3c_ibi_setup *req) +{ + struct i3c_generic_ibi_pool *pool; + struct i3c_generic_ibi_slot *slot; + unsigned int i; + int ret; + + pool = kzalloc(sizeof(*pool), GFP_KERNEL); + if (!pool) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&pool->lock); + INIT_LIST_HEAD(&pool->free_slots); + INIT_LIST_HEAD(&pool->pending); + + pool->slots = kcalloc(req->num_slots, sizeof(*slot), GFP_KERNEL); + if (!pool->slots) { + ret = -ENOMEM; + goto err_free_pool; + } + + if (req->max_payload_len) { + pool->payload_buf = kcalloc(req->num_slots, + req->max_payload_len, GFP_KERNEL); + if (!pool->payload_buf) { + ret = -ENOMEM; + goto err_free_pool; + } + } + + for (i = 0; i < req->num_slots; i++) { + slot = &pool->slots[i]; + i3c_master_init_ibi_slot(dev, &slot->base); + + if (req->max_payload_len) + slot->base.data = pool->payload_buf + + (i * req->max_payload_len); + + list_add_tail(&slot->node, &pool->free_slots); + pool->num_slots++; + } + + return pool; + +err_free_pool: + i3c_generic_ibi_free_pool(pool); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(i3c_generic_ibi_alloc_pool); + +/** + * i3c_generic_ibi_get_free_slot() - Get a free slot from a generic IBI pool + * @pool: the pool to query an IBI slot on + * + * Search for a free slot in a generic IBI pool. + * The slot should be returned to the pool using i3c_generic_ibi_recycle_slot() + * when it's no longer needed. + * + * Return: a pointer to a free slot, or NULL if there's no free slot available. + */ +struct i3c_ibi_slot * +i3c_generic_ibi_get_free_slot(struct i3c_generic_ibi_pool *pool) +{ + struct i3c_generic_ibi_slot *slot; + unsigned long flags; + + spin_lock_irqsave(&pool->lock, flags); + slot = list_first_entry_or_null(&pool->free_slots, + struct i3c_generic_ibi_slot, node); + if (slot) + list_del(&slot->node); + spin_unlock_irqrestore(&pool->lock, flags); + + return slot ? &slot->base : NULL; +} +EXPORT_SYMBOL_GPL(i3c_generic_ibi_get_free_slot); + +/** + * i3c_generic_ibi_recycle_slot() - Return a slot to a generic IBI pool + * @pool: the pool to return the IBI slot to + * @s: IBI slot to recycle + * + * Add an IBI slot back to its generic IBI pool. Should be called from the + * master driver struct_master_controller_ops->recycle_ibi() method. + */ +void i3c_generic_ibi_recycle_slot(struct i3c_generic_ibi_pool *pool, + struct i3c_ibi_slot *s) +{ + struct i3c_generic_ibi_slot *slot; + unsigned long flags; + + if (!s) + return; + + slot = container_of(s, struct i3c_generic_ibi_slot, base); + spin_lock_irqsave(&pool->lock, flags); + list_add_tail(&slot->node, &pool->free_slots); + spin_unlock_irqrestore(&pool->lock, flags); +} +EXPORT_SYMBOL_GPL(i3c_generic_ibi_recycle_slot); + +static void i3c_master_destroy_bus(struct i3c_master_controller *master) +{ + i3c_bus_unregister(master->bus); +} + +static int i3c_master_create_bus(struct i3c_master_controller *master) +{ + struct i3c_bus *i3cbus; + int ret; + + i3cbus = i3c_bus_create(master->parent); + if (IS_ERR(i3cbus)) + return PTR_ERR(i3cbus); + + master->bus = i3cbus; + + if (i3cbus->dev.of_node) { + ret = of_populate_i3c_bus(master); + if (ret) + goto err_destroy_bus; + } + + ret = i3c_bus_register(i3cbus); + if (ret) + goto err_destroy_bus; + + return 0; + +err_destroy_bus: + i3c_bus_unref(i3cbus); + + return ret; +} + +static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops) +{ + if (!ops || !ops->bus_init || !ops->priv_xfers || + !ops->send_ccc_cmd || !ops->do_daa || !ops->i2c_xfers || + !ops->i2c_funcs) + return -EINVAL; + + if (ops->request_ibi && + (!ops->enable_ibi || !ops->disable_ibi || !ops->free_ibi || + !ops->recycle_ibi_slot)) + return -EINVAL; + + return 0; +} + +/** + * i3c_master_register() - register an I3C master + * @master: master used to send frames on the bus + * @parent: the parent device (the one that provides this I3C master + * controller) + * @ops: the master controller operations + * @secondary: true if you are registering a secondary master. Will return + * -ENOTSUPP if set to true since secondary masters are not yet + * supported + * + * This function takes care of everything for you: + * + * - creates and initializes the I3C bus + * - populates the bus with static I2C devs if @parent->of_node is not + * NULL + * - registers all I3C devices added by the controller during bus + * initialization + * - registers the I2C adapter and all I2C devices + * + * Return: 0 in case of success, a negative error code otherwise. + */ +int i3c_master_register(struct i3c_master_controller *master, + struct device *parent, + const struct i3c_master_controller_ops *ops, + bool secondary) +{ + int ret; + + /* We do not support secondary masters yet. */ + if (secondary) + return -ENOTSUPP; + + ret = i3c_master_check_ops(ops); + if (ret) + return ret; + + master->parent = parent; + master->ops = ops; + master->secondary = secondary; + INIT_LIST_HEAD(&master->boardinfo.i2c); + INIT_LIST_HEAD(&master->boardinfo.i3c); + + ret = i3c_master_create_bus(master); + if (ret) + return ret; + + master->wq = alloc_workqueue("%s", 0, 0, dev_name(parent)); + if (!master->wq) { + ret = -ENOMEM; + goto err_destroy_bus; + } + + ret = i3c_master_bus_init(master); + if (ret) + goto err_destroy_wq; + + /* + * Expose our I3C bus as an I2C adapter so that I2C devices are exposed + * through the I2C subsystem. + */ + ret = i3c_master_i2c_adapter_init(master); + if (ret) + goto err_cleanup_bus; + + /* + * We're done initializing the bus and the controller, we can now + * register I3C devices dicovered during the initial DAA. + */ + master->init_done = true; + i3c_bus_normaluse_lock(master->bus); + i3c_master_register_new_i3c_devs(master); + i3c_bus_normaluse_unlock(master->bus); + + return 0; + +err_cleanup_bus: + i3c_master_bus_cleanup(master); + +err_destroy_wq: + destroy_workqueue(master->wq); + +err_destroy_bus: + i3c_master_destroy_bus(master); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_master_register); + +/** + * i3c_master_unregister() - unregister an I3C master + * @master: master used to send frames on the bus + * + * Basically undo everything done in i3c_master_register(). + * + * Return: 0 in case of success, a negative error code otherwise. + */ +int i3c_master_unregister(struct i3c_master_controller *master) +{ + i3c_master_i2c_adapter_cleanup(master); + i3c_master_unregister_i3c_devs(master); + i3c_master_bus_cleanup(master); + destroy_workqueue(master->wq); + i3c_master_destroy_bus(master); + + return 0; +} +EXPORT_SYMBOL_GPL(i3c_master_unregister); + +int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev, + struct i3c_priv_xfer *xfers, + int nxfers) +{ + struct i3c_master_controller *master; + + if (!dev) + return -ENOENT; + + master = i3c_dev_get_master(dev); + if (!master || !xfers) + return -EINVAL; + + if (!master->ops->priv_xfers) + return -ENOTSUPP; + + return master->ops->priv_xfers(dev, xfers, nxfers); +} + +int i3c_dev_disable_ibi_locked(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master; + int ret; + + if (!dev->ibi) + return -EINVAL; + + master = i3c_dev_get_master(dev); + ret = master->ops->disable_ibi(dev); + if (ret) + return ret; + + reinit_completion(&dev->ibi->all_ibis_handled); + if (atomic_read(&dev->ibi->pending_ibis)) + wait_for_completion(&dev->ibi->all_ibis_handled); + + dev->ibi->enabled = false; + + return 0; +} + +int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + int ret; + + if (!dev->ibi) + return -EINVAL; + + ret = master->ops->enable_ibi(dev); + if (!ret) + dev->ibi->enabled = true; + + return ret; +} + +int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev, + const struct i3c_ibi_setup *req) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + struct i3c_device_ibi_info *ibi; + int ret; + + if (!master->ops->request_ibi) + return -ENOTSUPP; + + if (dev->ibi) + return -EBUSY; + + ibi = kzalloc(sizeof(*ibi), GFP_KERNEL); + if (!ibi) + return -ENOMEM; + + atomic_set(&ibi->pending_ibis, 0); + init_completion(&ibi->all_ibis_handled); + ibi->handler = req->handler; + ibi->max_payload_len = req->max_payload_len; + ibi->num_slots = req->num_slots; + + dev->ibi = ibi; + ret = master->ops->request_ibi(dev, req); + if (ret) { + kfree(ibi); + dev->ibi = NULL; + } + + return ret; +} + +void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev) +{ + struct i3c_master_controller *master = i3c_dev_get_master(dev); + + if (!dev->ibi) + return; + + if (WARN_ON(dev->ibi->enabled)) + BUG_ON(i3c_dev_disable_ibi_locked(dev)); + + master->ops->free_ibi(dev); + kfree(dev->ibi); + dev->ibi = NULL; +} diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/drivers/i3c/master/Makefile b/drivers/i3c/master/Makefile new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/include/linux/i3c/ccc.h b/include/linux/i3c/ccc.h new file mode 100644 index 000000000000..4331ca648efe --- /dev/null +++ b/include/linux/i3c/ccc.h @@ -0,0 +1,385 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#ifndef I3C_CCC_H +#define I3C_CCC_H + +#include <linux/bitops.h> +#include <linux/i3c/device.h> + +/* I3C CCC (Common Command Codes) related definitions */ +#define I3C_CCC_DIRECT BIT(7) + +#define I3C_CCC_ID(id, broadcast) \ + ((id) | ((broadcast) ? 0 : I3C_CCC_DIRECT)) + +/* Commands valid in both broadcast and unicast modes */ +#define I3C_CCC_ENEC(broadcast) I3C_CCC_ID(0x0, broadcast) +#define I3C_CCC_DISEC(broadcast) I3C_CCC_ID(0x1, broadcast) +#define I3C_CCC_ENTAS(as, broadcast) I3C_CCC_ID(0x2 + (as), broadcast) +#define I3C_CCC_RSTDAA(broadcast) I3C_CCC_ID(0x6, broadcast) +#define I3C_CCC_SETMWL(broadcast) I3C_CCC_ID(0x9, broadcast) +#define I3C_CCC_SETMRL(broadcast) I3C_CCC_ID(0xa, broadcast) +#define I3C_CCC_SETXTIME(broadcast) ((broadcast) ? 0x28 : 0x98) +#define I3C_CCC_VENDOR(id, broadcast) ((id) + ((broadcast) ? 0x61 : 0xe0)) + +/* Broadcast-only commands */ +#define I3C_CCC_ENTDAA I3C_CCC_ID(0x7, true) +#define I3C_CCC_DEFSLVS I3C_CCC_ID(0x8, true) +#define I3C_CCC_ENTTM I3C_CCC_ID(0xb, true) +#define I3C_CCC_ENTHDR(x) I3C_CCC_ID(0x20 + (x), true) + +/* Unicast-only commands */ +#define I3C_CCC_SETDASA I3C_CCC_ID(0x7, false) +#define I3C_CCC_SETNEWDA I3C_CCC_ID(0x8, false) +#define I3C_CCC_GETMWL I3C_CCC_ID(0xb, false) +#define I3C_CCC_GETMRL I3C_CCC_ID(0xc, false) +#define I3C_CCC_GETPID I3C_CCC_ID(0xd, false) +#define I3C_CCC_GETBCR I3C_CCC_ID(0xe, false) +#define I3C_CCC_GETDCR I3C_CCC_ID(0xf, false) +#define I3C_CCC_GETSTATUS I3C_CCC_ID(0x10, false) +#define I3C_CCC_GETACCMST I3C_CCC_ID(0x11, false) +#define I3C_CCC_SETBRGTGT I3C_CCC_ID(0x13, false) +#define I3C_CCC_GETMXDS I3C_CCC_ID(0x14, false) +#define I3C_CCC_GETHDRCAP I3C_CCC_ID(0x15, false) +#define I3C_CCC_GETXTIME I3C_CCC_ID(0x19, false) + +#define I3C_CCC_EVENT_SIR BIT(0) +#define I3C_CCC_EVENT_MR BIT(1) +#define I3C_CCC_EVENT_HJ BIT(3) + +/** + * struct i3c_ccc_events - payload passed to ENEC/DISEC CCC + * + * @events: bitmask of I3C_CCC_EVENT_xxx events. + * + * Depending on the CCC command, the specific events coming from all devices + * (broadcast version) or a specific device (unicast version) will be + * enabled (ENEC) or disabled (DISEC). + */ +struct i3c_ccc_events { + u8 events; +}; + +/** + * struct i3c_ccc_mwl - payload passed to SETMWL/GETMWL CCC + * + * @len: maximum write length in bytes + * + * The maximum write length is only applicable to SDR private messages or + * extended Write CCCs (like SETXTIME). + */ +struct i3c_ccc_mwl { + __be16 len; +}; + +/** + * struct i3c_ccc_mrl - payload passed to SETMRL/GETMRL CCC + * + * @len: maximum read length in bytes + * @ibi_len: maximum IBI payload length + * + * The maximum read length is only applicable to SDR private messages or + * extended Read CCCs (like GETXTIME). + * The IBI length is only valid if the I3C slave is IBI capable + * (%I3C_BCR_IBI_REQ_CAP is set). + */ +struct i3c_ccc_mrl { + __be16 read_len; + u8 ibi_len; +} __packed; + +/** + * struct i3c_ccc_dev_desc - I3C/I2C device descriptor used for DEFSLVS + * + * @dyn_addr: dynamic address assigned to the I3C slave or 0 if the entry is + * describing an I2C slave. + * @dcr: DCR value (not applicable to entries describing I2C devices) + * @lvr: LVR value (not applicable to entries describing I3C devices) + * @bcr: BCR value or 0 if this entry is describing an I2C slave + * @static_addr: static address or 0 if the device does not have a static + * address + * + * The DEFSLVS command should be passed an array of i3c_ccc_dev_desc + * descriptors (one entry per I3C/I2C dev controlled by the master). + */ +struct i3c_ccc_dev_desc { + u8 dyn_addr; + union { + u8 dcr; + u8 lvr; + }; + u8 bcr; + u8 static_addr; +}; + +/** + * struct i3c_ccc_defslvs - payload passed to DEFSLVS CCC + * + * @count: number of dev descriptors + * @master: descriptor describing the current master + * @slaves: array of descriptors describing slaves controlled by the + * current master + * + * Information passed to the broadcast DEFSLVS to propagate device + * information to all masters currently acting as slaves on the bus. + * This is only meaningful if you have more than one master. + */ +struct i3c_ccc_defslvs { + u8 count; + struct i3c_ccc_dev_desc master; + struct i3c_ccc_dev_desc slaves[0]; +} __packed; + +/** + * enum i3c_ccc_test_mode - enum listing all available test modes + * + * @I3C_CCC_EXIT_TEST_MODE: exit test mode + * @I3C_CCC_VENDOR_TEST_MODE: enter vendor test mode + */ +enum i3c_ccc_test_mode { + I3C_CCC_EXIT_TEST_MODE, + I3C_CCC_VENDOR_TEST_MODE, +}; + +/** + * struct i3c_ccc_enttm - payload passed to ENTTM CCC + * + * @mode: one of the &enum i3c_ccc_test_mode modes + * + * Information passed to the ENTTM CCC to instruct an I3C device to enter a + * specific test mode. + */ +struct i3c_ccc_enttm { + u8 mode; +}; + +/** + * struct i3c_ccc_setda - payload passed to SETNEWDA and SETDASA CCCs + * + * @addr: dynamic address to assign to an I3C device + * + * Information passed to the SETNEWDA and SETDASA CCCs to assign/change the + * dynamic address of an I3C device. + */ +struct i3c_ccc_setda { + u8 addr; +}; + +/** + * struct i3c_ccc_getpid - payload passed to GETPID CCC + * + * @pid: 48 bits PID in big endian + */ +struct i3c_ccc_getpid { + u8 pid[6]; +}; + +/** + * struct i3c_ccc_getbcr - payload passed to GETBCR CCC + * + * @bcr: BCR (Bus Characteristic Register) value + */ +struct i3c_ccc_getbcr { + u8 bcr; +}; + +/** + * struct i3c_ccc_getdcr - payload passed to GETDCR CCC + * + * @dcr: DCR (Device Characteristic Register) value + */ +struct i3c_ccc_getdcr { + u8 dcr; +}; + +#define I3C_CCC_STATUS_PENDING_INT(status) ((status) & GENMASK(3, 0)) +#define I3C_CCC_STATUS_PROTOCOL_ERROR BIT(5) +#define I3C_CCC_STATUS_ACTIVITY_MODE(status) \ + (((status) & GENMASK(7, 6)) >> 6) + +/** + * struct i3c_ccc_getstatus - payload passed to GETSTATUS CCC + * + * @status: status of the I3C slave (see I3C_CCC_STATUS_xxx macros for more + * information). + */ +struct i3c_ccc_getstatus { + __be16 status; +}; + +/** + * struct i3c_ccc_getaccmst - payload passed to GETACCMST CCC + * + * @newmaster: address of the master taking bus ownership + */ +struct i3c_ccc_getaccmst { + u8 newmaster; +}; + +/** + * struct i3c_ccc_bridged_slave_desc - bridged slave descriptor + * + * @addr: dynamic address of the bridged device + * @id: ID of the slave device behind the bridge + */ +struct i3c_ccc_bridged_slave_desc { + u8 addr; + __be16 id; +} __packed; + +/** + * struct i3c_ccc_setbrgtgt - payload passed to SETBRGTGT CCC + * + * @count: number of bridged slaves + * @bslaves: bridged slave descriptors + */ +struct i3c_ccc_setbrgtgt { + u8 count; + struct i3c_ccc_bridged_slave_desc bslaves[0]; +} __packed; + +/** + * enum i3c_sdr_max_data_rate - max data rate values for private SDR transfers + */ +enum i3c_sdr_max_data_rate { + I3C_SDR0_FSCL_MAX, + I3C_SDR1_FSCL_8MHZ, + I3C_SDR2_FSCL_6MHZ, + I3C_SDR3_FSCL_4MHZ, + I3C_SDR4_FSCL_2MHZ, +}; + +/** + * enum i3c_tsco - clock to data turn-around + */ +enum i3c_tsco { + I3C_TSCO_8NS, + I3C_TSCO_9NS, + I3C_TSCO_10NS, + I3C_TSCO_11NS, + I3C_TSCO_12NS, +}; + +#define I3C_CCC_MAX_SDR_FSCL_MASK GENMASK(2, 0) +#define I3C_CCC_MAX_SDR_FSCL(x) ((x) & I3C_CCC_MAX_SDR_FSCL_MASK) + +/** + * struct i3c_ccc_getmxds - payload passed to GETMXDS CCC + * + * @maxwr: write limitations + * @maxrd: read limitations + * @maxrdturn: maximum read turn-around expressed micro-seconds and + * little-endian formatted + */ +struct i3c_ccc_getmxds { + u8 maxwr; + u8 maxrd; + u8 maxrdturn[3]; +} __packed; + +#define I3C_CCC_HDR_MODE(mode) BIT(mode) + +/** + * struct i3c_ccc_gethdrcap - payload passed to GETHDRCAP CCC + * + * @modes: bitmap of supported HDR modes + */ +struct i3c_ccc_gethdrcap { + u8 modes; +} __packed; + +/** + * enum i3c_ccc_setxtime_subcmd - SETXTIME sub-commands + */ +enum i3c_ccc_setxtime_subcmd { + I3C_CCC_SETXTIME_ST = 0x7f, + I3C_CCC_SETXTIME_DT = 0xbf, + I3C_CCC_SETXTIME_ENTER_ASYNC_MODE0 = 0xdf, + I3C_CCC_SETXTIME_ENTER_ASYNC_MODE1 = 0xef, + I3C_CCC_SETXTIME_ENTER_ASYNC_MODE2 = 0xf7, + I3C_CCC_SETXTIME_ENTER_ASYNC_MODE3 = 0xfb, + I3C_CCC_SETXTIME_ASYNC_TRIGGER = 0xfd, + I3C_CCC_SETXTIME_TPH = 0x3f, + I3C_CCC_SETXTIME_TU = 0x9f, + I3C_CCC_SETXTIME_ODR = 0x8f, +}; + +/** + * struct i3c_ccc_setxtime - payload passed to SETXTIME CCC + * + * @subcmd: one of the sub-commands ddefined in &enum i3c_ccc_setxtime_subcmd + * @data: sub-command payload. Amount of data is determined by + * &i3c_ccc_setxtime->subcmd + */ +struct i3c_ccc_setxtime { + u8 subcmd; + u8 data[0]; +} __packed; + +#define I3C_CCC_GETXTIME_SYNC_MODE BIT(0) +#define I3C_CCC_GETXTIME_ASYNC_MODE(x) BIT((x) + 1) +#define I3C_CCC_GETXTIME_OVERFLOW BIT(7) + +/** + * struct i3c_ccc_getxtime - payload retrieved from GETXTIME CCC + * + * @supported_modes: bitmap describing supported XTIME modes + * @state: current status (enabled mode and overflow status) + * @frequency: slave's internal oscillator frequency in 500KHz steps + * @inaccuracy: slave's internal oscillator inaccuracy in 0.1% steps + */ +struct i3c_ccc_getxtime { + u8 supported_modes; + u8 state; + u8 frequency; + u8 inaccuracy; +} __packed; + +/** + * struct i3c_ccc_cmd_payload - CCC payload + * + * @len: payload length + * @data: payload data + */ +struct i3c_ccc_cmd_payload { + u16 len; + void *data; +}; + +/** + * struct i3c_ccc_cmd_dest - CCC command destination + * + * @addr: can be an I3C device address or the broadcast address if this is a + * broadcast CCC + * @payload: payload to be sent to this device or broadcasted + */ +struct i3c_ccc_cmd_dest { + u8 addr; + struct i3c_ccc_cmd_payload payload; +}; + +/** + * struct i3c_ccc_cmd - CCC command + * + * @rnw: true if the CCC should retrieve data from the device. Only valid for + * unicast commands + * @id: CCC command id + * @ndests: number of destinations. Should always be one for broadcast commands + * @dests: array of destinations and associated payload for this CCC. Most of + * the time, only one destination is provided + * @err: I3C error code + */ +struct i3c_ccc_cmd { + bool rnw; + u8 id; + int ndests; + struct i3c_ccc_cmd_dest *dests; + enum i3c_error_code err; +}; + +#endif /* I3C_CCC_H */ diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h new file mode 100644 index 000000000000..ef0a25706f18 --- /dev/null +++ b/include/linux/i3c/device.h @@ -0,0 +1,331 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#ifndef I3C_DEV_H +#define I3C_DEV_H + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/kconfig.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> + +/** + * enum i3c_error_code - I3C error codes + * + * These are the standard error codes as defined by the I3C specification. + * When -EIO is returned by the i3c_device_do_priv_xfers() or + * i3c_device_send_hdr_cmds() one can check the error code in + * &struct_i3c_priv_xfer.err or &struct i3c_hdr_cmd.err to get a better idea of + * what went wrong. + * + * @I3C_ERROR_UNKNOWN: unknown error, usually means the error is not I3C + * related + * @I3C_ERROR_M0: M0 error + * @I3C_ERROR_M1: M1 error + * @I3C_ERROR_M2: M2 error + */ +enum i3c_error_code { + I3C_ERROR_UNKNOWN = 0, + I3C_ERROR_M0 = 1, + I3C_ERROR_M1, + I3C_ERROR_M2, +}; + +/** + * enum i3c_hdr_mode - HDR mode ids + * @I3C_HDR_DDR: DDR mode + * @I3C_HDR_TSP: TSP mode + * @I3C_HDR_TSL: TSL mode + */ +enum i3c_hdr_mode { + I3C_HDR_DDR, + I3C_HDR_TSP, + I3C_HDR_TSL, +}; + +/** + * struct i3c_priv_xfer - I3C SDR private transfer + * @rnw: encodes the transfer direction. true for a read, false for a write + * @len: transfer length in bytes of the transfer + * @data: input/output buffer + * @data.in: input buffer. Must point to a DMA-able buffer + * @data.out: output buffer. Must point to a DMA-able buffer + * @err: I3C error code + */ +struct i3c_priv_xfer { + bool rnw; + u16 len; + union { + void *in; + const void *out; + } data; + enum i3c_error_code err; +}; + +/** + * enum i3c_dcr - I3C DCR values + * @I3C_DCR_GENERIC_DEVICE: generic I3C device + */ +enum i3c_dcr { + I3C_DCR_GENERIC_DEVICE = 0, +}; + +#define I3C_PID_MANUF_ID(pid) (((pid) & GENMASK_ULL(47, 33)) >> 33) +#define I3C_PID_RND_LOWER_32BITS(pid) (!!((pid) & BIT_ULL(32))) +#define I3C_PID_RND_VAL(pid) ((pid) & GENMASK_ULL(31, 0)) +#define I3C_PID_PART_ID(pid) (((pid) & GENMASK_ULL(31, 16)) >> 16) +#define I3C_PID_INSTANCE_ID(pid) (((pid) & GENMASK_ULL(15, 12)) >> 12) +#define I3C_PID_EXTRA_INFO(pid) ((pid) & GENMASK_ULL(11, 0)) + +#define I3C_BCR_DEVICE_ROLE(bcr) ((bcr) & GENMASK(7, 6)) +#define I3C_BCR_I3C_SLAVE (0 << 6) +#define I3C_BCR_I3C_MASTER (1 << 6) +#define I3C_BCR_HDR_CAP BIT(5) +#define I3C_BCR_BRIDGE BIT(4) +#define I3C_BCR_OFFLINE_CAP BIT(3) +#define I3C_BCR_IBI_PAYLOAD BIT(2) +#define I3C_BCR_IBI_REQ_CAP BIT(1) +#define I3C_BCR_MAX_DATA_SPEED_LIM BIT(0) + +/** + * struct i3c_device_info - I3C device information + * @pid: Provisional ID + * @bcr: Bus Characteristic Register + * @dcr: Device Characteristic Register + * @static_addr: static/I2C address + * @dyn_addr: dynamic address + * @hdr_cap: supported HDR modes + * @max_read_ds: max read speed information + * @max_write_ds: max write speed information + * @max_ibi_len: max IBI payload length + * @max_read_turnaround: max read turn-around time in micro-seconds + * @max_read_len: max private SDR read length in bytes + * @max_write_len: max private SDR write length in bytes + * + * These are all basic information that should be advertised by an I3C device. + * Some of them are optional depending on the device type and device + * capabilities. + * For each I3C slave attached to a master with + * i3c_master_add_i3c_dev_locked(), the core will send the relevant CCC command + * to retrieve these data. + */ +struct i3c_device_info { + u64 pid; + u8 bcr; + u8 dcr; + u8 static_addr; + u8 dyn_addr; + u8 hdr_cap; + u8 max_read_ds; + u8 max_write_ds; + u8 max_ibi_len; + u32 max_read_turnaround; + u16 max_read_len; + u16 max_write_len; +}; + +/* + * I3C device internals are kept hidden from I3C device users. It's just + * simpler to refactor things when everything goes through getter/setters, and + * I3C device drivers should not have to worry about internal representation + * anyway. + */ +struct i3c_device; + +/* These macros should be used to i3c_device_id entries. */ +#define I3C_MATCH_MANUF_AND_PART (I3C_MATCH_MANUF | I3C_MATCH_PART) + +#define I3C_DEVICE(_manufid, _partid, _drvdata) \ + { \ + .match_flags = I3C_MATCH_MANUF_AND_PART, \ + .manuf_id = _manufid, \ + .part_id = _partid, \ + .data = _drvdata, \ + } + +#define I3C_DEVICE_EXTRA_INFO(_manufid, _partid, _info, _drvdata) \ + { \ + .match_flags = I3C_MATCH_MANUF_AND_PART | \ + I3C_MATCH_EXTRA_INFO, \ + .manuf_id = _manufid, \ + .part_id = _partid, \ + .extra_info = _info, \ + .data = _drvdata, \ + } + +#define I3C_CLASS(_dcr, _drvdata) \ + { \ + .match_flags = I3C_MATCH_DCR, \ + .dcr = _dcr, \ + } + +/** + * struct i3c_driver - I3C device driver + * @driver: inherit from device_driver + * @probe: I3C device probe method + * @remove: I3C device remove method + * @id_table: I3C device match table. Will be used by the framework to decide + * which device to bind to this driver + */ +struct i3c_driver { + struct device_driver driver; + int (*probe)(struct i3c_device *dev); + int (*remove)(struct i3c_device *dev); + const struct i3c_device_id *id_table; +}; + +static inline struct i3c_driver *drv_to_i3cdrv(struct device_driver *drv) +{ + return container_of(drv, struct i3c_driver, driver); +} + +struct device *i3cdev_to_dev(struct i3c_device *i3cdev); +struct i3c_device *dev_to_i3cdev(struct device *dev); + +static inline void i3cdev_set_drvdata(struct i3c_device *i3cdev, + void *data) +{ + struct device *dev = i3cdev_to_dev(i3cdev); + + dev_set_drvdata(dev, data); +} + +static inline void *i3cdev_get_drvdata(struct i3c_device *i3cdev) +{ + struct device *dev = i3cdev_to_dev(i3cdev); + + return dev_get_drvdata(dev); +} + +int i3c_driver_register_with_owner(struct i3c_driver *drv, + struct module *owner); +void i3c_driver_unregister(struct i3c_driver *drv); + +#define i3c_driver_register(__drv) \ + i3c_driver_register_with_owner(__drv, THIS_MODULE) + +/** + * module_i3c_driver() - Register a module providing an I3C driver + * @__drv: the I3C driver to register + * + * Provide generic init/exit functions that simply register/unregister an I3C + * driver. + * Should be used by any driver that does not require extra init/cleanup steps. + */ +#define module_i3c_driver(__drv) \ + module_driver(__drv, i3c_driver_register, i3c_driver_unregister) + +/** + * i3c_i2c_driver_register() - Register an i2c and an i3c driver + * @i3cdrv: the I3C driver to register + * @i2cdrv: the I2C driver to register + * + * This function registers both @i2cdev and @i3cdev, and fails if one of these + * registrations fails. This is mainly useful for devices that support both I2C + * and I3C modes. + * Note that when CONFIG_I3C is not enabled, this function only registers the + * I2C driver. + * + * Return: 0 if both registrations succeeds, a negative error code otherwise. + */ +static inline int i3c_i2c_driver_register(struct i3c_driver *i3cdrv, + struct i2c_driver *i2cdrv) +{ + int ret; + + ret = i2c_add_driver(i2cdrv); + if (ret || !IS_ENABLED(CONFIG_I3C)) + return ret; + + ret = i3c_driver_register(i3cdrv); + if (ret) + i2c_del_driver(i2cdrv); + + return ret; +} + +/** + * i3c_i2c_driver_unregister() - Unregister an i2c and an i3c driver + * @i3cdrv: the I3C driver to register + * @i2cdrv: the I2C driver to register + * + * This function unregisters both @i3cdrv and @i2cdrv. + * Note that when CONFIG_I3C is not enabled, this function only unregisters the + * @i2cdrv. + */ +static inline void i3c_i2c_driver_unregister(struct i3c_driver *i3cdrv, + struct i2c_driver *i2cdrv) +{ + if (IS_ENABLED(CONFIG_I3C)) + i3c_driver_unregister(i3cdrv); + + i2c_del_driver(i2cdrv); +} + +/** + * module_i3c_i2c_driver() - Register a module providing an I3C and an I2C + * driver + * @__i3cdrv: the I3C driver to register + * @__i2cdrv: the I3C driver to register + * + * Provide generic init/exit functions that simply register/unregister an I3C + * and an I2C driver. + * This macro can be used even if CONFIG_I3C is disabled, in this case, only + * the I2C driver will be registered. + * Should be used by any driver that does not require extra init/cleanup steps. + */ +#define module_i3c_i2c_driver(__i3cdrv, __i2cdrv) \ + module_driver(__i3cdrv, \ + i3c_i2c_driver_register, \ + i3c_i2c_driver_unregister) + +int i3c_device_do_priv_xfers(struct i3c_device *dev, + struct i3c_priv_xfer *xfers, + int nxfers); + +void i3c_device_get_info(struct i3c_device *dev, struct i3c_device_info *info); + +struct i3c_ibi_payload { + unsigned int len; + const void *data; +}; + +/** + * struct i3c_ibi_setup - IBI setup object + * @max_payload_len: maximum length of the payload associated to an IBI. If one + * IBI appears to have a payload that is bigger than this + * number, the IBI will be rejected. + * @num_slots: number of pre-allocated IBI slots. This should be chosen so that + * the system never runs out of IBI slots, otherwise you'll lose + * IBIs. + * @handler: IBI handler, every time an IBI is received. This handler is called + * in a workqueue context. It is allowed to sleep and send new + * messages on the bus, though it's recommended to keep the + * processing done there as fast as possible to avoid delaying + * processing of other queued on the same workqueue. + * + * Temporary structure used to pass information to i3c_device_request_ibi(). + * This object can be allocated on the stack since i3c_device_request_ibi() + * copies every bit of information and do not use it after + * i3c_device_request_ibi() has returned. + */ +struct i3c_ibi_setup { + unsigned int max_payload_len; + unsigned int num_slots; + void (*handler)(struct i3c_device *dev, + const struct i3c_ibi_payload *payload); +}; + +int i3c_device_request_ibi(struct i3c_device *dev, + const struct i3c_ibi_setup *setup); +void i3c_device_free_ibi(struct i3c_device *dev); +int i3c_device_enable_ibi(struct i3c_device *dev); +int i3c_device_disable_ibi(struct i3c_device *dev); + +#endif /* I3C_DEV_H */ diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h new file mode 100644 index 000000000000..f512b713daf4 --- /dev/null +++ b/include/linux/i3c/master.h @@ -0,0 +1,652 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#ifndef I3C_MASTER_H +#define I3C_MASTER_H + +#include <asm/bitsperlong.h> + +#include <linux/bitops.h> +#include <linux/i2c.h> +#include <linux/i3c/ccc.h> +#include <linux/i3c/device.h> +#include <linux/rwsem.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> + +#define I3C_HOT_JOIN_ADDR 0x2 +#define I3C_BROADCAST_ADDR 0x7e +#define I3C_MAX_ADDR GENMASK(6, 0) + +struct i3c_master_controller; +struct i3c_bus; +struct i2c_device; +struct i3c_device; + +/** + * struct i3c_i2c_dev_desc - Common part of the I3C/I2C device descriptor + * @node: node element used to insert the slot into the I2C or I3C device + * list + * @master: I3C master that instantiated this device. Will be used to do + * I2C/I3C transfers + * @master_priv: master private data assigned to the device. Can be used to + * add master specific information + * + * This structure is describing common I3C/I2C dev information. + */ +struct i3c_i2c_dev_desc { + struct list_head node; + struct i3c_master_controller *master; + void *master_priv; +}; + +#define I3C_LVR_I2C_INDEX_MASK GENMASK(7, 5) +#define I3C_LVR_I2C_INDEX(x) ((x) << 5) +#define I3C_LVR_I2C_FM_MODE BIT(4) + +#define I2C_MAX_ADDR GENMASK(9, 0) + +/** + * struct i2c_dev_boardinfo - I2C device board information + * @node: used to insert the boardinfo object in the I2C boardinfo list + * @base: regular I2C board information + * @lvr: LVR (Legacy Virtual Register) needed by the I3C core to know about + * the I2C device limitations + * + * This structure is used to attach board-level information to an I2C device. + * Each I2C device connected on the I3C bus should have one. + */ +struct i2c_dev_boardinfo { + struct list_head node; + struct i2c_board_info base; + u8 lvr; +}; + +/** + * struct i2c_dev_desc - I2C device descriptor + * @common: common part of the I2C device descriptor + * @boardinfo: pointer to the boardinfo attached to this I2C device + * @dev: I2C device object registered to the I2C framework + * + * Each I2C device connected on the bus will have an i2c_dev_desc. + * This object is created by the core and later attached to the controller + * using &struct_i3c_master_controller->ops->attach_i2c_dev(). + * + * &struct_i2c_dev_desc is the internal representation of an I2C device + * connected on an I3C bus. This object is also passed to all + * &struct_i3c_master_controller_ops hooks. + */ +struct i2c_dev_desc { + struct i3c_i2c_dev_desc common; + const struct i2c_dev_boardinfo *boardinfo; + struct i2c_client *dev; +}; + +/** + * struct i3c_ibi_slot - I3C IBI (In-Band Interrupt) slot + * @work: work associated to this slot. The IBI handler will be called from + * there + * @dev: the I3C device that has generated this IBI + * @len: length of the payload associated to this IBI + * @data: payload buffer + * + * An IBI slot is an object pre-allocated by the controller and used when an + * IBI comes in. + * Every time an IBI comes in, the I3C master driver should find a free IBI + * slot in its IBI slot pool, retrieve the IBI payload and queue the IBI using + * i3c_master_queue_ibi(). + * + * How IBI slots are allocated is left to the I3C master driver, though, for + * simple kmalloc-based allocation, the generic IBI slot pool can be used. + */ +struct i3c_ibi_slot { + struct work_struct work; + struct i3c_dev_desc *dev; + unsigned int len; + void *data; +}; + +/** + * struct i3c_device_ibi_info - IBI information attached to a specific device + * @all_ibis_handled: used to be informed when no more IBIs are waiting to be + * processed. Used by i3c_device_disable_ibi() to wait for + * all IBIs to be dequeued + * @pending_ibis: count the number of pending IBIs. Each pending IBI has its + * work element queued to the controller workqueue + * @max_payload_len: maximum payload length for an IBI coming from this device. + * this value is specified when calling + * i3c_device_request_ibi() and should not change at run + * time. All messages IBIs exceeding this limit should be + * rejected by the master + * @num_slots: number of IBI slots reserved for this device + * @enabled: reflect the IBI status + * @handler: IBI handler specified at i3c_device_request_ibi() call time. This + * handler will be called from the controller workqueue, and as such + * is allowed to sleep (though it is recommended to process the IBI + * as fast as possible to not stall processing of other IBIs queued + * on the same workqueue). + * New I3C messages can be sent from the IBI handler + * + * The &struct_i3c_device_ibi_info object is allocated when + * i3c_device_request_ibi() is called and attached to a specific device. This + * object is here to manage IBIs coming from a specific I3C device. + * + * Note that this structure is the generic view of the IBI management + * infrastructure. I3C master drivers may have their own internal + * representation which they can associate to the device using + * controller-private data. + */ +struct i3c_device_ibi_info { + struct completion all_ibis_handled; + atomic_t pending_ibis; + unsigned int max_payload_len; + unsigned int num_slots; + bool enabled; + void (*handler)(struct i3c_device *dev, + const struct i3c_ibi_payload *payload); +}; + +/** + * struct i3c_dev_boardinfo - I3C device board information + * @node: used to insert the boardinfo object in the I3C boardinfo list + * @init_dyn_addr: initial dynamic address requested by the FW. We provide no + * guarantee that the device will end up using this address, + * but try our best to assign this specific address to the + * device + * @static_addr: static address the I3C device listen on before it's been + * assigned a dynamic address by the master. Will be used during + * bus initialization to assign it a specific dynamic address + * before starting DAA (Dynamic Address Assignment) + * @pid: I3C Provisional ID exposed by the device. This is a unique identifier + * that may be used to attach boardinfo to i3c_dev_desc when the device + * does not have a static address + * @of_node: optional DT node in case the device has been described in the DT + * + * This structure is used to attach board-level information to an I3C device. + * Not all I3C devices connected on the bus will have a boardinfo. It's only + * needed if you want to attach extra resources to a device or assign it a + * specific dynamic address. + */ +struct i3c_dev_boardinfo { + struct list_head node; + u8 init_dyn_addr; + u8 static_addr; + u64 pid; + struct device_node *of_node; +}; + +/** + * struct i3c_dev_desc - I3C device descriptor + * @common: common part of the I3C device descriptor + * @info: I3C device information. Will be automatically filled when you create + * your device with i3c_master_add_i3c_dev_locked() + * @ibi_lock: lock used to protect the &struct_i3c_device->ibi + * @ibi: IBI info attached to a device. Should be NULL until + * i3c_device_request_ibi() is called + * @dev: pointer to the I3C device object exposed to I3C device drivers. This + * should never be accessed from I3C master controller drivers. Only core + * code should manipulate it in when updating the dev <-> desc link or + * when propagating IBI events to the driver + * @boardinfo: pointer to the boardinfo attached to this I3C device + * + * Internal representation of an I3C device. This object is only used by the + * core and passed to I3C master controller drivers when they're requested to + * do some operations on the device. + * The core maintains the link between the internal I3C dev descriptor and the + * object exposed to the I3C device drivers (&struct_i3c_device). + */ +struct i3c_dev_desc { + struct i3c_i2c_dev_desc common; + struct i3c_device_info info; + struct mutex ibi_lock; + struct i3c_device_ibi_info *ibi; + struct i3c_device *dev; + const struct i3c_dev_boardinfo *boardinfo; +}; + +/** + * struct i3c_device - I3C device object + * @dev: device object to register the I3C dev to the device model + * @desc: pointer to an i3c device descriptor object. This link is updated + * every time the I3C device is rediscovered with a different dynamic + * address assigned + * @bus: I3C bus this device is attached to + * + * I3C device object exposed to I3C device drivers. The takes care of linking + * this object to the relevant &struct_i3c_dev_desc one. + * All I3C devs on the I3C bus are represented, including I3C masters. For each + * of them, we have an instance of &struct i3c_device. + */ +struct i3c_device { + struct device dev; + struct i3c_dev_desc *desc; + struct i3c_bus *bus; +}; + +/* + * The I3C specification says the maximum number of devices connected on the + * bus is 11, but this number depends on external parameters like trace length, + * capacitive load per Device, and the types of Devices present on the Bus. + * I3C master can also have limitations, so this number is just here as a + * reference and should be adjusted on a per-controller/per-board basis. + */ +#define I3C_BUS_MAX_DEVS 11 + +#define I3C_BUS_MAX_I3C_SCL_RATE 12900000 +#define I3C_BUS_TYP_I3C_SCL_RATE 12500000 +#define I3C_BUS_I2C_FM_PLUS_SCL_RATE 1000000 +#define I3C_BUS_I2C_FM_SCL_RATE 400000 +#define I3C_BUS_TLOW_OD_MIN_NS 200 + +/** + * enum i3c_bus_mode - I3C bus mode + * @I3C_BUS_MODE_PURE: only I3C devices are connected to the bus. No limitation + * expected + * @I3C_BUS_MODE_MIXED_FAST: I2C devices with 50ns spike filter are present on + * the bus. The only impact in this mode is that the + * high SCL pulse has to stay below 50ns to trick I2C + * devices when transmitting I3C frames + * @I3C_BUS_MODE_MIXED_SLOW: I2C devices without 50ns spike filter are present + * on the bus + */ +enum i3c_bus_mode { + I3C_BUS_MODE_PURE, + I3C_BUS_MODE_MIXED_FAST, + I3C_BUS_MODE_MIXED_SLOW, +}; + +/** + * enum i3c_addr_slot_status - I3C address slot status + * @I3C_ADDR_SLOT_FREE: address is free + * @I3C_ADDR_SLOT_RSVD: address is reserved + * @I3C_ADDR_SLOT_I2C_DEV: address is assigned to an I2C device + * @I3C_ADDR_SLOT_I3C_DEV: address is assigned to an I3C device + * @I3C_ADDR_SLOT_STATUS_MASK: address slot mask + * + * On an I3C bus, addresses are assigned dynamically, and we need to know which + * addresses are free to use and which ones are already assigned. + * + * Addresses marked as reserved are those reserved by the I3C protocol + * (broadcast address, ...). + */ +enum i3c_addr_slot_status { + I3C_ADDR_SLOT_FREE, + I3C_ADDR_SLOT_RSVD, + I3C_ADDR_SLOT_I2C_DEV, + I3C_ADDR_SLOT_I3C_DEV, + I3C_ADDR_SLOT_STATUS_MASK = 3, +}; + +/** + * struct i3c_bus - I3C bus object + * @dev: device to be registered to the device-model + * @cur_master: I3C master currently driving the bus. Since I3C is multi-master + * this can change over the time. Will be used to let a master + * know whether it needs to request bus ownership before sending + * a frame or not + * @id: bus ID. Assigned by the framework when register the bus + * @addrslots: a bitmap with 2-bits per-slot to encode the address status and + * ease the DAA (Dynamic Address Assignment) procedure (see + * &enum i3c_addr_slot_status) + * @mode: bus mode (see &enum i3c_bus_mode) + * @scl_rate.i3c: maximum rate for the clock signal when doing I3C SDR/priv + * transfers + * @scl_rate.i2c: maximum rate for the clock signal when doing I2C transfers + * @scl_rate: SCL signal rate for I3C and I2C mode + * @devs.i3c: contains a list of I3C device descriptors representing I3C + * devices connected on the bus and successfully attached to the + * I3C master + * @devs.i2c: contains a list of I2C device descriptors representing I2C + * devices connected on the bus and successfully attached to the + * I3C master + * @devs: 2 lists containing all I3C/I2C devices connected to the bus + * @lock: read/write lock on the bus. This is needed to protect against + * operations that have an impact on the whole bus and the devices + * connected to it. For example, when asking slaves to drop their + * dynamic address (RSTDAA CCC), we need to make sure no one is trying + * to send I3C frames to these devices. + * Note that this lock does not protect against concurrency between + * devices: several drivers can send different I3C/I2C frames through + * the same master in parallel. This is the responsibility of the + * master to guarantee that frames are actually sent sequentially and + * not interlaced + * + * The I3C bus is represented with its own object and not implicitly described + * by the I3C master to cope with the multi-master functionality, where one bus + * can be shared amongst several masters, each of them requesting bus ownership + * when they need to. + */ +struct i3c_bus { + struct device dev; + struct i3c_dev_desc *cur_master; + int id; + unsigned long addrslots[((I2C_MAX_ADDR + 1) * 2) / BITS_PER_LONG]; + enum i3c_bus_mode mode; + struct { + unsigned long i3c; + unsigned long i2c; + } scl_rate; + struct { + struct list_head i3c; + struct list_head i2c; + } devs; + struct rw_semaphore lock; +}; + +struct i3c_master_controller; + +/** + * struct i3c_master_controller_ops - I3C master methods + * @bus_init: hook responsible for the I3C bus initialization. You should at + * least call master_set_info() from there and set the bus mode. + * You can also put controller specific initialization in there. + * This method is mandatory. + * @bus_cleanup: cleanup everything done in + * &i3c_master_controller_ops->bus_init(). + * This method is optional. + * @attach_i3c_dev: called every time an I3C device is attached to the bus. It + * can be after a DAA or when a device is statically declared + * by the FW, in which case it will only have a static address + * and the dynamic address will be 0. + * When this function is called, device information have not + * been retrieved yet. + * This is a good place to attach master controller specific + * data to I3C devices. + * This method is optional. + * @reattach_i3c_dev: called every time an I3C device has its addressed + * changed. It can be because the device has been powered + * down and has lost its address, or it can happen when a + * device had a static address and has been assigned a + * dynamic address with SETDASA. + * This method is optional. + * @detach_i3c_dev: called when an I3C device is detached from the bus. Usually + * happens when the master device is unregistered. + * This method is optional. + * @do_daa: do a DAA (Dynamic Address Assignment) procedure. This is procedure + * should send an ENTDAA CCC command and then add all devices + * discovered sure the DAA using i3c_master_add_i3c_dev_locked(). + * Add devices added with i3c_master_add_i3c_dev_locked() will then be + * attached or re-attached to the controller. + * This method is mandatory. + * @supports_ccc_cmd: should return true if the CCC command is supported, false + * otherwise. + * This method is optional, if not provided the core assumes + * all CCC commands are supported. + * @send_ccc_cmd: send a CCC command + * This method is mandatory. + * @priv_xfers: do one or several private I3C SDR transfers + * This method is mandatory. + * @attach_i2c_dev: called every time an I2C device is attached to the bus. + * This is a good place to attach master controller specific + * data to I2C devices. + * This method is optional. + * @detach_i2c_dev: called when an I2C device is detached from the bus. Usually + * happens when the master device is unregistered. + * This method is optional. + * @i2c_xfers: do one or several I2C transfers. + * This method is mandatory. + * @i2c_funcs: expose the supported I2C functionalities. + * This method is mandatory. + * @request_ibi: attach an IBI handler to an I3C device. This implies defining + * an IBI handler and the constraints of the IBI (maximum payload + * length and number of pre-allocated slots). + * Some controllers support less IBI-capable devices than regular + * devices, so this method might return -%EBUSY if there's no + * more space for an extra IBI registration + * This method is optional. + * @free_ibi: free an IBI previously requested with ->request_ibi(). The IBI + * should have been disabled with ->disable_irq() prior to that + * This method is mandatory only if ->request_ibi is not NULL. + * @enable_ibi: enable the IBI. Only valid if ->request_ibi() has been called + * prior to ->enable_ibi(). The controller should first enable + * the IBI on the controller end (for example, unmask the hardware + * IRQ) and then send the ENEC CCC command (with the IBI flag set) + * to the I3C device. + * This method is mandatory only if ->request_ibi is not NULL. + * @disable_ibi: disable an IBI. First send the DISEC CCC command with the IBI + * flag set and then deactivate the hardware IRQ on the + * controller end. + * This method is mandatory only if ->request_ibi is not NULL. + * @recycle_ibi_slot: recycle an IBI slot. Called every time an IBI has been + * processed by its handler. The IBI slot should be put back + * in the IBI slot pool so that the controller can re-use it + * for a future IBI + * This method is mandatory only if ->request_ibi is not + * NULL. + */ +struct i3c_master_controller_ops { + int (*bus_init)(struct i3c_master_controller *master); + void (*bus_cleanup)(struct i3c_master_controller *master); + int (*attach_i3c_dev)(struct i3c_dev_desc *dev); + int (*reattach_i3c_dev)(struct i3c_dev_desc *dev, u8 old_dyn_addr); + void (*detach_i3c_dev)(struct i3c_dev_desc *dev); + int (*do_daa)(struct i3c_master_controller *master); + bool (*supports_ccc_cmd)(struct i3c_master_controller *master, + const struct i3c_ccc_cmd *cmd); + int (*send_ccc_cmd)(struct i3c_master_controller *master, + struct i3c_ccc_cmd *cmd); + int (*priv_xfers)(struct i3c_dev_desc *dev, + struct i3c_priv_xfer *xfers, + int nxfers); + int (*attach_i2c_dev)(struct i2c_dev_desc *dev); + void (*detach_i2c_dev)(struct i2c_dev_desc *dev); + int (*i2c_xfers)(struct i2c_dev_desc *dev, + const struct i2c_msg *xfers, int nxfers); + u32 (*i2c_funcs)(struct i3c_master_controller *master); + int (*request_ibi)(struct i3c_dev_desc *dev, + const struct i3c_ibi_setup *req); + void (*free_ibi)(struct i3c_dev_desc *dev); + int (*enable_ibi)(struct i3c_dev_desc *dev); + int (*disable_ibi)(struct i3c_dev_desc *dev); + void (*recycle_ibi_slot)(struct i3c_dev_desc *dev, + struct i3c_ibi_slot *slot); +}; + +/** + * struct i3c_master_controller - I3C master controller object + * @parent: parent device that instantiated this master + * @this: an I3C device object representing this master. This device will be + * added to the list of I3C devs available on the bus + * @i2c: I2C adapter used for backward compatibility. This adapter is + * registered to the I2C subsystem to be as transparent as possible to + * existing I2C drivers + * @ops: master operations. See &struct i3c_master_controller_ops + * @secondary: true if the master is a secondary master + * @init_done: true when the bus initialization is done + * @boardinfo.i3c: list of I3C boardinfo objects + * @boardinfo.i2c: list of I2C boardinfo objects + * @boardinfo: board-level information attached to devices connected on the bus + * @bus: I3C bus object created by this master + * @wq: workqueue used to execute IBI handlers. Can also be used by master + * drivers if they need to postpone operations that need to take place + * in a thread context. Typical examples are Hot Join processing which + * requires taking the bus lock in maintenance, which in turn, can only + * be done from a sleep-able context + * + * A &struct i3c_master_controller has to be registered to the I3C subsystem + * through i3c_master_register(). None of &struct i3c_master_controller fields + * should be set manually, just pass appropriate values to + * i3c_master_register(). + */ +struct i3c_master_controller { + struct device *parent; + struct i3c_dev_desc *this; + struct i2c_adapter i2c; + const struct i3c_master_controller_ops *ops; + bool secondary; + bool init_done; + struct { + struct list_head i3c; + struct list_head i2c; + } boardinfo; + struct i3c_bus *bus; + struct workqueue_struct *wq; +}; + +/** + * i3c_bus_for_each_i2cdev() - iterate over all I2C devices present on the bus + * @bus: the I3C bus + * @dev: an I2C device descriptor pointer updated to point to the current slot + * at each iteration of the loop + * + * Iterate over all I2C devs present on the bus. + */ +#define i3c_bus_for_each_i2cdev(bus, dev) \ + list_for_each_entry(dev, &(bus)->devs.i2c, common.node) + +/** + * i3c_bus_for_each_i3cdev() - iterate over all I3C devices present on the bus + * @bus: the I3C bus + * @dev: and I3C device descriptor pointer updated to point to the current slot + * at each iteration of the loop + * + * Iterate over all I3C devs present on the bus. + */ +#define i3c_bus_for_each_i3cdev(bus, dev) \ + list_for_each_entry(dev, &(bus)->devs.i3c, common.node) + +void i3c_bus_maintenance_lock(struct i3c_bus *bus); +void i3c_bus_maintenance_unlock(struct i3c_bus *bus); +void i3c_bus_normaluse_lock(struct i3c_bus *bus); +void i3c_bus_normaluse_unlock(struct i3c_bus *bus); + +int i3c_master_do_i2c_xfers(struct i3c_master_controller *master, + const struct i2c_msg *xfers, + int nxfers); + +int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr, + u8 evts); +int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr, + u8 evts); +int i3c_master_entdaa_locked(struct i3c_master_controller *master); +int i3c_master_defslvs_locked(struct i3c_master_controller *master); + +int i3c_master_get_free_addr(struct i3c_master_controller *master, + u8 start_addr); + +int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master, + u8 addr); +int i3c_master_do_daa(struct i3c_master_controller *master); + +int i3c_master_set_info(struct i3c_master_controller *master, + const struct i3c_device_info *info); + +int i3c_master_register(struct i3c_master_controller *master, + struct device *parent, + const struct i3c_master_controller_ops *ops, + bool secondary); +int i3c_master_unregister(struct i3c_master_controller *master); + +/** + * i3c_dev_get_master_data() - get master private data attached to an I3C + * device descriptor + * @dev: the I3C device descriptor to get private data from + * + * Return: the private data previously attached with i3c_dev_set_master_data() + * or NULL if no data has been attached to the device. + */ +static inline void *i3c_dev_get_master_data(const struct i3c_dev_desc *dev) +{ + return dev->common.master_priv; +} + +/** + * i3c_dev_set_master_data() - attach master private data to an I3C device + * descriptor + * @dev: the I3C device descriptor to attach private data to + * @data: private data + * + * This functions allows a master controller to attach per-device private data + * which can then be retrieved with i3c_dev_get_master_data(). + */ +static inline void i3c_dev_set_master_data(struct i3c_dev_desc *dev, + void *data) +{ + dev->common.master_priv = data; +} + +/** + * i2c_dev_get_master_data() - get master private data attached to an I2C + * device descriptor + * @dev: the I2C device descriptor to get private data from + * + * Return: the private data previously attached with i2c_dev_set_master_data() + * or NULL if no data has been attached to the device. + */ +static inline void *i2c_dev_get_master_data(const struct i2c_dev_desc *dev) +{ + return dev->common.master_priv; +} + +/** + * i2c_dev_set_master_data() - attach master private data to an I2C device + * descriptor + * @dev: the I2C device descriptor to attach private data to + * @data: private data + * + * This functions allows a master controller to attach per-device private data + * which can then be retrieved with i2c_device_get_master_data(). + */ +static inline void i2c_dev_set_master_data(struct i2c_dev_desc *dev, + void *data) +{ + dev->common.master_priv = data; +} + +/** + * i3c_dev_get_master() - get master used to communicate with a device + * @dev: I3C dev + * + * Return: the master controller driving @dev + */ +static inline struct i3c_master_controller * +i3c_dev_get_master(struct i3c_dev_desc *dev) +{ + return dev->common.master; +} + +/** + * i2c_dev_get_master() - get master used to communicate with a device + * @dev: I2C dev + * + * Return: the master controller driving @dev + */ +static inline struct i3c_master_controller * +i2c_dev_get_master(struct i2c_dev_desc *dev) +{ + return dev->common.master; +} + +/** + * i3c_master_get_bus() - get the bus attached to a master + * @master: master object + * + * Return: the I3C bus @master is connected to + */ +static inline struct i3c_bus * +i3c_master_get_bus(struct i3c_master_controller *master) +{ + return master->bus; +} + +struct i3c_generic_ibi_pool; + +struct i3c_generic_ibi_pool * +i3c_generic_ibi_alloc_pool(struct i3c_dev_desc *dev, + const struct i3c_ibi_setup *req); +void i3c_generic_ibi_free_pool(struct i3c_generic_ibi_pool *pool); + +struct i3c_ibi_slot * +i3c_generic_ibi_get_free_slot(struct i3c_generic_ibi_pool *pool); +void i3c_generic_ibi_recycle_slot(struct i3c_generic_ibi_pool *pool, + struct i3c_ibi_slot *slot); + +void i3c_master_queue_ibi(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot); + +struct i3c_ibi_slot *i3c_master_get_free_ibi_slot(struct i3c_dev_desc *dev); + +#endif /* I3C_MASTER_H */ diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index 96a71a648eed..870392478d66 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -448,6 +448,23 @@ struct pci_epf_device_id { kernel_ulong_t driver_data; }; +/* i3c */ + +#define I3C_MATCH_DCR 0x1 +#define I3C_MATCH_MANUF 0x2 +#define I3C_MATCH_PART 0x4 +#define I3C_MATCH_EXTRA_INFO 0x8 + +struct i3c_device_id { + __u8 match_flags; + __u8 dcr; + __u16 manuf_id; + __u16 part_id; + __u16 extra_info; + + const void *data; +}; + /* spi */ #define SPI_NAME_SIZE 32
Add core infrastructure to support I3C in Linux and document it. This infrastructure is not complete yet and will be extended over time. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is still open to discussion. Please let me know if you think it's worth considering an asynchronous model here - the bus element is a separate object and is not implicitly described by the master (as done in I2C). The reason is that I want to be able to handle multiple master connected to the same bus and visible to Linux. In this situation, we should only have one instance of the device and not one per master, and sharing the bus object would be part of the solution to gracefully handle this case. I'm not sure we will ever need to deal with multiple masters controlling the same bus and exposed under Linux, but separating the bus and master concept is pretty easy, hence the decision to do it like that. The other benefit of separating the bus and master concepts is that master devices appear under the bus directory in sysfs. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different busses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features in this preliminary version: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> --- Changes in v6: - Add I3C/I2C dev descriptors to simplify I3C driver controllers when migrating resources from on I3C device slot to anoter - Add I3C error codes and return them when doing SDR/priv and CCC transfers. This allows us to properly detect when no devices acked a CCC command, which in some cases is a valid situation (no I3C devices on the bus) - Remove __packed specifiers where unneeded - Allocate all IBI slots in one call using kcalloc() Changes in v5: - Rename the address sysfs entry into dynamic_address to clarify things - Document that we expect buffers passed to i3c_device_do_priv_xfers() to be DMA-able - Fix DEFSLVS CCC command - s/2017/2018/ in copyright headers - Fix SPDX header in internals.h - Fix coding style issues Changes in v4: - none Changes in v3: - Fix locking issues - Explicitly include a bunch of headers (reported by Randy Dunlap) - Rename {i2c,i3c}-scl-frequency DT prop into {i2c,i3c}-scl-hz - Do not use BIT() macro in mod_devicetable.h - Fix typos - Fix/enhance some kernel doc headers - Rework the bus initialization code to simplify master drivers - Assign dynamic address with SETDASA if the device has a static address and the DT has a valid assigned-address property - Rework the LVR extraction in DT parsing code - Add code to detect when a device is re-attached to the bus after losing its dynamic address. In this case we know try to re-assign the old address, and most importantly, the I3C device driver sees the same device instance, not a new one - Add an ->i2c_funcs() hook to let the master declare which I2C features it supports - Unexport a few functions - Remove support for HDR mode since we have no real user yet Changes in v2: - Fix a bunch of mistake I made with the device model (pointed by GKH) - Move the documentation out of this commit (pointed by GKH) - only source drivers/i3c/master/Kconfig when CONFIG_I3C is enabled (pointed by GKH) - Add IBI infrastructure - Add helpers to ease support for Hot Join (most of the logic is delegated to I3C controller drivers) - move the doc out of this commit to improve readability - Fix a few bugs in device probing/remove (detected after trying to load/unload modules in various orders) - Add a module_i3c_i2c_driver() macro to ease integration of drivers for devices that support both I3C and I2C mode --- drivers/Kconfig | 2 + drivers/Makefile | 2 +- drivers/i3c/Kconfig | 24 + drivers/i3c/Makefile | 4 + drivers/i3c/core.c | 606 ++++++++++++ drivers/i3c/device.c | 233 +++++ drivers/i3c/internals.h | 36 + drivers/i3c/master.c | 2058 +++++++++++++++++++++++++++++++++++++++ drivers/i3c/master/Kconfig | 0 drivers/i3c/master/Makefile | 0 include/linux/i3c/ccc.h | 385 ++++++++ include/linux/i3c/device.h | 331 +++++++ include/linux/i3c/master.h | 652 +++++++++++++ include/linux/mod_devicetable.h | 17 + 14 files changed, 4349 insertions(+), 1 deletion(-) create mode 100644 drivers/i3c/Kconfig create mode 100644 drivers/i3c/Makefile create mode 100644 drivers/i3c/core.c create mode 100644 drivers/i3c/device.c create mode 100644 drivers/i3c/internals.h create mode 100644 drivers/i3c/master.c create mode 100644 drivers/i3c/master/Kconfig create mode 100644 drivers/i3c/master/Makefile create mode 100644 include/linux/i3c/ccc.h create mode 100644 include/linux/i3c/device.h create mode 100644 include/linux/i3c/master.h