Message ID | 20180608211113.10238-2-hdegoede@redhat.com |
---|---|
State | Superseded |
Headers | show |
Series | [1/2] i2c: Add new I2C_CLIENT_IGNORE_BUSY flag | expand |
On Fri, 2018-06-08 at 23:11 +0200, Hans de Goede wrote: > On systems with ACPI instantiated i2c-clients, normally there is 1 > fw_node > per i2c-device and that fw-node contains 1 I2cSerialBus resource for > that 1 > i2c-device. > > But in some rare cases the manufacturer has decided to describe > multiple > i2c-devices in a single ACPI fwnode with multiple I2cSerialBus > resources. > > An earlier attempt to fix this in the i2c-core resulted in a lot of > extra > code to support this corner-case. > > This commitintroduces a new i2c-multi-instantiate driver which fixes > this > in a different way. This new driver can be built as a module which > will > only loaded on affected systems. > > This driver will instantiate a new i2c-client per I2cSerialBus > resource, > using the driver_data from the acpi_device_id it is binding to to tell > it > which chip-type (and optional irq-resource) to use when instantiating. > > Note this means that we will be instantiating 2 i2c_client-s for the > first > I2cSerialBus resource, this is not pretty, but since the multi- > instantiate > driver does exactly 0 i2c-transfers this is not a problem. > You forgot to Cc Heikki. > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/i2c/Kconfig | 8 ++ > drivers/i2c/Makefile | 1 + > drivers/i2c/i2c-multi-instantiate.c | 125 > ++++++++++++++++++++++++++++ > 3 files changed, 134 insertions(+) > create mode 100644 drivers/i2c/i2c-multi-instantiate.c > > diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig > index efc3354d60ae..12ca950e7549 100644 > --- a/drivers/i2c/Kconfig > +++ b/drivers/i2c/Kconfig > @@ -120,6 +120,14 @@ config I2C_SLAVE_EEPROM > > endif > > +config I2C_MULTI_INSTANTIATE > + tristate "I2C multi instantiate pseudo device driver" > + depends on ACPI > + help > + Some ACPI bases systems list multiple i2c-devices in a > single ACPI > + firmware-node. This driver will instantiate separate i2c- > clients > + for each device in the firmware-node. > + > config I2C_DEBUG_CORE > bool "I2C Core debugging messages" > help > diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile > index 72c94c60fdd1..d9c5bae1d64f 100644 > --- a/drivers/i2c/Makefile > +++ b/drivers/i2c/Makefile > @@ -16,6 +16,7 @@ obj-$(CONFIG_I2C_MUX) += i2c-mux.o > obj-y += algos/ busses/ muxes/ > obj-$(CONFIG_I2C_STUB) += i2c-stub.o > obj-$(CONFIG_I2C_SLAVE_EEPROM) += i2c-slave-eeprom.o > +obj-$(CONFIG_I2C_MULTI_INSTANTIATE) += i2c-multi-instantiate.o > > ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG > CFLAGS_i2c-core-base.o := -Wno-deprecated-declarations > diff --git a/drivers/i2c/i2c-multi-instantiate.c b/drivers/i2c/i2c- > multi-instantiate.c > new file mode 100644 > index 000000000000..480b7a694eae > --- /dev/null > +++ b/drivers/i2c/i2c-multi-instantiate.c > @@ -0,0 +1,125 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * I2C multi-instantiate driver, pseudo driver to instantiate > multiple > + * i2c-clients from a single fwnode. > + * > + * Copyright 2018 Hans de Goede <hdegoede@redhat.com> > + */ > + > +#include <linux/acpi.h> > +#include <linux/i2c.h> > +#include <linux/interrupt.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > + > +struct i2c_inst_data { > + const char *type; > + int irq_idx; > +}; > + > +struct i2c_multi_inst_data { > + int no_clients; > + struct i2c_client *clients[0]; > +}; > + > +static int i2c_multi_inst_probe(struct i2c_client *client) > +{ > + struct i2c_multi_inst_data *multi; > + const struct i2c_inst_data *inst_data; > + struct i2c_board_info board_info = {}; > + struct device *dev = &client->dev; > + struct acpi_device *adev; > + char name[32]; > + int i, ret; > + > + inst_data = acpi_device_get_match_data(dev); > + if (!inst_data) { > + dev_err(dev, "Error ACPI match data is missing\n"); > + return -ENODEV; > + } > + > + adev = ACPI_COMPANION(dev); > + > + /* Count number of clients to instantiate */ > + for (i = 0; inst_data[i].type; i++) {} > + > + multi = devm_kmalloc(dev, > + offsetof(struct i2c_multi_inst_data, > clients[i]), > + GFP_KERNEL); > + if (!multi) > + return -ENOMEM; > + > + multi->no_clients = i; > + > + for (i = 0; i < multi->no_clients; i++) { > + memset(&board_info, 0, sizeof(board_info)); > + strlcpy(board_info.type, inst_data[i].type, > I2C_NAME_SIZE); > + board_info.flags = (i == 0) ? I2C_CLIENT_IGNORE_BUSY > : 0; > + snprintf(name, sizeof(name), "%s-%s", client->name, > + inst_data[i].type); > + board_info.dev_name = name; > + board_info.irq = 0; > + if (inst_data[i].irq_idx != -1) { > + ret = acpi_dev_gpio_irq_get(adev, > inst_data[i].irq_idx); > + if (ret < 0) { > + dev_err(dev, "Error requesting irq at > index %d: %d\n", > + inst_data[i].irq_idx, ret); > + goto error; > + } > + board_info.irq = ret; > + } > + multi->clients[i] = i2c_acpi_new_device(dev, i, > &board_info); > + if (!multi->clients[i]) { > + dev_err(dev, "Error creating i2c-client, idx > %d\n", i); > + ret = -ENODEV; > + goto error; > + } > + } > + > + return 0; > + > +error: > + while (--i >= 0) > + i2c_unregister_device(multi->clients[i]); > + > + return ret; > +} > + > +static int i2c_multi_inst_remove(struct i2c_client *i2c) > +{ > + struct i2c_multi_inst_data *multi = i2c_get_clientdata(i2c); > + int i; > + > + for (i = 0; i < multi->no_clients; i++) > + i2c_unregister_device(multi->clients[i]); > + > + return 0; > +} > + > +static const struct i2c_inst_data bsg1160_data[] = { > + { "bmc150_accel", 0 }, > + { "bmc150_magn", -1 }, > + { "bmg160", -1 }, > + {} > +}; > + > +static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = { > + { "BSG1160", (unsigned long)bsg1160_data }, > + { } > +}; > +MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids); > + > +static struct i2c_driver i2c_multi_inst_driver = { > + .driver = { > + .name = "I2C multi instantiate pseudo device driver", > + .acpi_match_table = > ACPI_PTR(i2c_multi_inst_acpi_ids), > + }, > + .probe_new = i2c_multi_inst_probe, > + .remove = i2c_multi_inst_remove, > +}; > + > +module_i2c_driver(i2c_multi_inst_driver); > + > +MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver"); > +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); > +MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index efc3354d60ae..12ca950e7549 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -120,6 +120,14 @@ config I2C_SLAVE_EEPROM endif +config I2C_MULTI_INSTANTIATE + tristate "I2C multi instantiate pseudo device driver" + depends on ACPI + help + Some ACPI bases systems list multiple i2c-devices in a single ACPI + firmware-node. This driver will instantiate separate i2c-clients + for each device in the firmware-node. + config I2C_DEBUG_CORE bool "I2C Core debugging messages" help diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 72c94c60fdd1..d9c5bae1d64f 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_I2C_MUX) += i2c-mux.o obj-y += algos/ busses/ muxes/ obj-$(CONFIG_I2C_STUB) += i2c-stub.o obj-$(CONFIG_I2C_SLAVE_EEPROM) += i2c-slave-eeprom.o +obj-$(CONFIG_I2C_MULTI_INSTANTIATE) += i2c-multi-instantiate.o ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG CFLAGS_i2c-core-base.o := -Wno-deprecated-declarations diff --git a/drivers/i2c/i2c-multi-instantiate.c b/drivers/i2c/i2c-multi-instantiate.c new file mode 100644 index 000000000000..480b7a694eae --- /dev/null +++ b/drivers/i2c/i2c-multi-instantiate.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * I2C multi-instantiate driver, pseudo driver to instantiate multiple + * i2c-clients from a single fwnode. + * + * Copyright 2018 Hans de Goede <hdegoede@redhat.com> + */ + +#include <linux/acpi.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> + +struct i2c_inst_data { + const char *type; + int irq_idx; +}; + +struct i2c_multi_inst_data { + int no_clients; + struct i2c_client *clients[0]; +}; + +static int i2c_multi_inst_probe(struct i2c_client *client) +{ + struct i2c_multi_inst_data *multi; + const struct i2c_inst_data *inst_data; + struct i2c_board_info board_info = {}; + struct device *dev = &client->dev; + struct acpi_device *adev; + char name[32]; + int i, ret; + + inst_data = acpi_device_get_match_data(dev); + if (!inst_data) { + dev_err(dev, "Error ACPI match data is missing\n"); + return -ENODEV; + } + + adev = ACPI_COMPANION(dev); + + /* Count number of clients to instantiate */ + for (i = 0; inst_data[i].type; i++) {} + + multi = devm_kmalloc(dev, + offsetof(struct i2c_multi_inst_data, clients[i]), + GFP_KERNEL); + if (!multi) + return -ENOMEM; + + multi->no_clients = i; + + for (i = 0; i < multi->no_clients; i++) { + memset(&board_info, 0, sizeof(board_info)); + strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE); + board_info.flags = (i == 0) ? I2C_CLIENT_IGNORE_BUSY : 0; + snprintf(name, sizeof(name), "%s-%s", client->name, + inst_data[i].type); + board_info.dev_name = name; + board_info.irq = 0; + if (inst_data[i].irq_idx != -1) { + ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx); + if (ret < 0) { + dev_err(dev, "Error requesting irq at index %d: %d\n", + inst_data[i].irq_idx, ret); + goto error; + } + board_info.irq = ret; + } + multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info); + if (!multi->clients[i]) { + dev_err(dev, "Error creating i2c-client, idx %d\n", i); + ret = -ENODEV; + goto error; + } + } + + return 0; + +error: + while (--i >= 0) + i2c_unregister_device(multi->clients[i]); + + return ret; +} + +static int i2c_multi_inst_remove(struct i2c_client *i2c) +{ + struct i2c_multi_inst_data *multi = i2c_get_clientdata(i2c); + int i; + + for (i = 0; i < multi->no_clients; i++) + i2c_unregister_device(multi->clients[i]); + + return 0; +} + +static const struct i2c_inst_data bsg1160_data[] = { + { "bmc150_accel", 0 }, + { "bmc150_magn", -1 }, + { "bmg160", -1 }, + {} +}; + +static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = { + { "BSG1160", (unsigned long)bsg1160_data }, + { } +}; +MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids); + +static struct i2c_driver i2c_multi_inst_driver = { + .driver = { + .name = "I2C multi instantiate pseudo device driver", + .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids), + }, + .probe_new = i2c_multi_inst_probe, + .remove = i2c_multi_inst_remove, +}; + +module_i2c_driver(i2c_multi_inst_driver); + +MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver"); +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_LICENSE("GPL");
On systems with ACPI instantiated i2c-clients, normally there is 1 fw_node per i2c-device and that fw-node contains 1 I2cSerialBus resource for that 1 i2c-device. But in some rare cases the manufacturer has decided to describe multiple i2c-devices in a single ACPI fwnode with multiple I2cSerialBus resources. An earlier attempt to fix this in the i2c-core resulted in a lot of extra code to support this corner-case. This commitintroduces a new i2c-multi-instantiate driver which fixes this in a different way. This new driver can be built as a module which will only loaded on affected systems. This driver will instantiate a new i2c-client per I2cSerialBus resource, using the driver_data from the acpi_device_id it is binding to to tell it which chip-type (and optional irq-resource) to use when instantiating. Note this means that we will be instantiating 2 i2c_client-s for the first I2cSerialBus resource, this is not pretty, but since the multi-instantiate driver does exactly 0 i2c-transfers this is not a problem. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/i2c/Kconfig | 8 ++ drivers/i2c/Makefile | 1 + drivers/i2c/i2c-multi-instantiate.c | 125 ++++++++++++++++++++++++++++ 3 files changed, 134 insertions(+) create mode 100644 drivers/i2c/i2c-multi-instantiate.c