Message ID | 1514202808-29747-2-git-send-email-oleksandrs@mellanox.com |
---|---|
State | Not Applicable, archived |
Headers | show |
Series | JTAG driver introduction | expand |
Le 12/25/17 à 03:53, Oleksandr Shamray a écrit : > Initial patch for JTAG driver > JTAG class driver provide infrastructure to support hardware/software > JTAG platform drivers. It provide user layer API interface for flashing > and debugging external devices which equipped with JTAG interface > using standard transactions. > > Driver exposes set of IOCTL to user space for: > - XFER: > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan); > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan); > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified > number of clocks). > - SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency. > > Driver core provides set of internal APIs for allocation and > registration: > - jtag_register; > - jtag_unregister; > - jtag_alloc; > - jtag_free; > > Platform driver on registration with jtag-core creates the next > entry in dev folder: > /dev/jtagX Just some general comment, I am really surprised to see that there is not a whole lot of generic code, actually, there is none, which tries to manage the JTAG devices command queue, e.g: ala OpenOCD. All that this is doing here is create a special character device with a bunch of custom ioctl(), which means that a lot of code is going to be put within in individual drivers. Have you given some thoughts on how you would expand this framework for non ASPEED JTAG adapters? For instance, one expectation is to see a bit-banged GPIO master, since that's quite common, what would it look like here? How much code would I have to write? [snip] > + > +void *jtag_priv(struct jtag *jtag) > +{ > + return jtag->priv; > +} > +EXPORT_SYMBOL_GPL(jtag_priv); Can't you just create a static inline function in the public header for that? This is usually what subsystems do, I can understand why you would not want to expose struct jtag to other parts of the kernel, but still, this looks ugly, so maybe consider splitting the header between provider and consumer? > + > +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > +{ > + struct jtag *jtag = file->private_data; > + struct jtag_run_test_idle idle; > + struct jtag_xfer xfer; > + u8 *xfer_data; > + u32 data_size; > + u32 value; > + int err; > + > + if (!arg) > + return -EINVAL; > + > + switch (cmd) { > + case JTAG_GIOCFREQ: > + > + if (jtag->ops->freq_get) > + err = jtag->ops->freq_get(jtag, &value); > + else > + err = -EOPNOTSUPP; > + if (err) > + break; > + > + if (put_user(value, (__u32 *)arg)) > + err = -EFAULT; > + break; > + > + case JTAG_SIOCFREQ: > + if (get_user(value, (__u32 *)arg)) > + return -EFAULT; > + if (value == 0) > + return -EINVAL; > + > + if (jtag->ops->freq_set) > + err = jtag->ops->freq_set(jtag, value); > + else > + err = -EOPNOTSUPP; You should check that before get_user() > + break; > + > + case JTAG_IOCRUNTEST: > + if (copy_from_user(&idle, (void *)arg, > + sizeof(struct jtag_run_test_idle))) > + return -EFAULT; > + > + if (idle.endstate > JTAG_STATE_PAUSEDR) > + return -EINVAL; > + > + if (jtag->ops->idle) > + err = jtag->ops->idle(jtag, &idle); > + else > + err = -EOPNOTSUPP; > + break; Same here. > + > + case JTAG_IOCXFER: > + if (copy_from_user(&xfer, (void *)arg, > + sizeof(struct jtag_xfer))) > + return -EFAULT; > + > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN) > + return -EINVAL; > + > + if (xfer.type > JTAG_SDR_XFER) > + return -EINVAL; > + > + if (xfer.direction > JTAG_WRITE_XFER) > + return -EINVAL; > + > + if (xfer.endstate > JTAG_STATE_PAUSEDR) > + return -EINVAL; > + > + data_size = DIV_ROUND_UP(xfer.length, BITS_PER_BYTE); > + xfer_data = memdup_user(u64_to_user_ptr(xfer.tdio), data_size); > + > + if (!xfer_data) > + return -EFAULT; > + > + if (jtag->ops->xfer) { > + err = jtag->ops->xfer(jtag, &xfer, xfer_data); > + } else { > + kfree(xfer_data); > + return -EOPNOTSUPP; > + } Why don't you move all of the code here into a function which will make the error handling consistent? Also, checking whether the jtag adapter implements ops->xfer should probably be done before you do the memdup_user(). > + > + if (err) { > + kfree(xfer_data); > + return -EFAULT; > + } > + > + err = copy_to_user(u64_to_user_ptr(xfer.tdio), > + (void *)(xfer_data), data_size); > + > + if (err) { > + kfree(xfer_data); > + return -EFAULT; > + } > + > + kfree(xfer_data); > + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer))) > + return -EFAULT; > + break; > + > + case JTAG_GIOCSTATUS: > + if (jtag->ops->status_get) > + err = jtag->ops->status_get(jtag, &value); > + else > + err = -EOPNOTSUPP; > + if (err) > + break; > + > + err = put_user(value, (__u32 *)arg); > + if (err) > + err = -EFAULT; > + break; > + case JTAG_SIOCMODE: > + if (get_user(value, (__u32 *)arg)) > + return -EFAULT; > + if (value == 0) > + return -EINVAL; > + > + if (jtag->ops->mode_set) > + err = jtag->ops->mode_set(jtag, value); > + else > + err = -EOPNOTSUPP; > + break; Same here, this can be checked before get_user(). > + > + default: > + return -EINVAL; > + } > + return err; > +} > + > +static int jtag_open(struct inode *inode, struct file *file) > +{ > + struct jtag *jtag = container_of(file->private_data, struct jtag, > + miscdev); > + > + if (mutex_lock_interruptible(&jtag->open_lock)) > + return -ERESTARTSYS; > + > + if (jtag->opened) { > + mutex_unlock(&jtag->open_lock); > + return -EINVAL; -EBUSY maybe? > + } > + > + nonseekable_open(inode, file); > + file->private_data = jtag; > + jtag->opened = true; > + mutex_unlock(&jtag->open_lock); > + return 0; > +} > + > +static int jtag_release(struct inode *inode, struct file *file) > +{ > + struct jtag *jtag = file->private_data; > + > + mutex_lock(&jtag->open_lock); > + jtag->opened = false; > + mutex_unlock(&jtag->open_lock); > + return 0; > +} > + > +static const struct file_operations jtag_fops = { > + .owner = THIS_MODULE, > + .open = jtag_open, > + .release = jtag_release, > + .llseek = noop_llseek, > + .unlocked_ioctl = jtag_ioctl, > +}; > + > +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops) > +{ > + struct jtag *jtag; > + > + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN), > + GFP_KERNEL); > + if (!jtag) > + return NULL; If you set ARCH_DMA_MINALIGN to 1 when not defined, what is this achieving that kmalloc() is not already doing? > + > + jtag->ops = ops; > + return jtag; > +} > +EXPORT_SYMBOL_GPL(jtag_alloc); > + > +void jtag_free(struct jtag *jtag) > +{ > + kfree(jtag); > +} > +EXPORT_SYMBOL_GPL(jtag_free); > + > +int jtag_register(struct jtag *jtag) > +{ > + char *name; > + int err; > + int id; > + > + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL); > + if (id < 0) > + return id; > + > + jtag->id = id; > + > + name = kzalloc(MAX_JTAG_NAME_LEN, GFP_KERNEL); > + if (!name) { > + err = -ENOMEM; > + goto err_jtag_alloc; > + } Can't you use jtag->miscdev.dev here to simplify the allocation error handling? > + > + err = snprintf(name, MAX_JTAG_NAME_LEN, "jtag%d", id); > + if (err < 0) > + goto err_jtag_name; > + > + mutex_init(&jtag->open_lock); > + jtag->miscdev.fops = &jtag_fops; > + jtag->miscdev.minor = MISC_DYNAMIC_MINOR; > + jtag->miscdev.name = name; > + > + err = misc_register(&jtag->miscdev); > + if (err) > + dev_err(jtag->dev, "Unable to register device\n"); > + else > + return 0; > + jtag->opened = false; > + > +err_jtag_name: > + kfree(name); > +err_jtag_alloc: > + ida_simple_remove(&jtag_ida, id); > + return err; > +} > +EXPORT_SYMBOL_GPL(jtag_register); > + > +void jtag_unregister(struct jtag *jtag) > +{ > + misc_deregister(&jtag->miscdev); > + kfree(jtag->miscdev.name); > + ida_simple_remove(&jtag_ida, jtag->id); > +} > +EXPORT_SYMBOL_GPL(jtag_unregister); > + > +static void __exit jtag_exit(void) > +{ > + ida_destroy(&jtag_ida); > +} > + > +module_exit(jtag_exit); > + > +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>"); > +MODULE_DESCRIPTION("Generic jtag support"); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/jtag.h b/include/linux/jtag.h > new file mode 100644 > index 0000000..312c641 > --- /dev/null > +++ b/include/linux/jtag.h > @@ -0,0 +1,45 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// include/linux/jtag.h - JTAG class driver > +// > +// Copyright (c) 2017 Mellanox Technologies. All rights reserved. > +// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com> > + > +#ifndef __JTAG_H > +#define __JTAG_H > + > +#include <uapi/linux/jtag.h> > + > +#ifndef ARCH_DMA_MINALIGN > +#define ARCH_DMA_MINALIGN 1 > +#endif Why? > + > +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg) > + > +#define JTAG_MAX_XFER_DATA_LEN 65535 > + > +struct jtag; > +/** > + * struct jtag_ops - callbacks for jtag control functions: > + * > + * @freq_get: get frequency function. Filled by device driver > + * @freq_set: set frequency function. Filled by device driver > + * @status_get: set status function. Filled by device driver > + * @idle: set JTAG to idle state function. Filled by device driver > + * @xfer: send JTAG xfer function. Filled by device driver > + */ > +struct jtag_ops { > + int (*freq_get)(struct jtag *jtag, u32 *freq); > + int (*freq_set)(struct jtag *jtag, u32 freq); > + int (*status_get)(struct jtag *jtag, u32 *state); > + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle); > + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer, u8 *xfer_data); > + int (*mode_set)(struct jtag *jtag, u32 mode_mask); > +}; > + > +void *jtag_priv(struct jtag *jtag); > +int jtag_register(struct jtag *jtag); > +void jtag_unregister(struct jtag *jtag); > +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops); > +void jtag_free(struct jtag *jtag); > + > +#endif /* __JTAG_H */ > diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h > new file mode 100644 > index 0000000..cda2520 > --- /dev/null > +++ b/include/uapi/linux/jtag.h [snip] > +struct jtag_xfer { > + __u8 type; > + __u8 direction; Can these two be an enum referring to what you defined earlier? > + __u8 endstate; > + __u32 length; > + __u64 tdio; > +};
Tue, Dec 26, 2017 at 12:09:08AM CET, f.fainelli@gmail.com wrote: >Le 12/25/17 à 03:53, Oleksandr Shamray a écrit : [...] >[snip] > >> + >> +void *jtag_priv(struct jtag *jtag) >> +{ >> + return jtag->priv; >> +} >> +EXPORT_SYMBOL_GPL(jtag_priv); > >Can't you just create a static inline function in the public header for >that? This is usually what subsystems do, I can understand why you would >not want to expose struct jtag to other parts of the kernel, but still, >this looks ugly, so maybe consider splitting the header between provider >and consumer? Other subsystems expose the struct. Here, it is intentional to don't expose the struct, that's why we have this helper. What is ugly about that? :)
> -----Original Message----- > From: Florian Fainelli [mailto:f.fainelli@gmail.com] > Sent: 26 декабря 2017 г. 1:09 > To: Oleksandr Shamray <oleksandrs@mellanox.com>; > gregkh@linuxfoundation.org; arnd@arndb.de > Cc: linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; > devicetree@vger.kernel.org; openbmc@lists.ozlabs.org; joel@jms.id.au; > jiri@resnulli.us; tklauser@distanz.ch; linux-serial@vger.kernel.org; Vadim > Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low- > level@mellanox.com>; robh+dt@kernel.org; openocd-devel- > owner@lists.sourceforge.net; linux-api@vger.kernel.org; > davem@davemloft.net; mchehab@kernel.org; Jiri Pirko > <jiri@mellanox.com> > Subject: Re: [patch v15 1/4] drivers: jtag: Add JTAG core driver > > [snip] > > + > > + case JTAG_IOCXFER: > > + if (copy_from_user(&xfer, (void *)arg, > > + sizeof(struct jtag_xfer))) > > + return -EFAULT; > > + > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN) > > + return -EINVAL; > > + > > + if (xfer.type > JTAG_SDR_XFER) > > + return -EINVAL; > > + > > + if (xfer.direction > JTAG_WRITE_XFER) > > + return -EINVAL; > > + > > + if (xfer.endstate > JTAG_STATE_PAUSEDR) > > + return -EINVAL; > > + > > + data_size = DIV_ROUND_UP(xfer.length, BITS_PER_BYTE); > > + xfer_data = memdup_user(u64_to_user_ptr(xfer.tdio), > data_size); > > + > > + if (!xfer_data) > > + return -EFAULT; > > + > > + if (jtag->ops->xfer) { > > + err = jtag->ops->xfer(jtag, &xfer, xfer_data); > > + } else { > > + kfree(xfer_data); > > + return -EOPNOTSUPP; > > + } > > Why don't you move all of the code here into a function which will make the > error handling consistent? Also, checking whether the jtag adapter Greg KH <gregkh@linuxfoundation.org> Say to move all of this insight ioctl > implements ops->xfer should probably be done before you do the > memdup_user(). Yes > > + if (err) { > > + kfree(xfer_data); > > + return -EFAULT; > > + } > > + > > + if (jtag->ops->mode_set) > > + err = jtag->ops->mode_set(jtag, value); > > + else > > + err = -EOPNOTSUPP; > > + break; > > Same here, this can be checked before get_user(). > Yes > > + if (jtag->opened) { > > + mutex_unlock(&jtag->open_lock); > > + return -EINVAL; > > -EBUSY maybe? > Yes > > + > > + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, > ARCH_DMA_MINALIGN), > > + GFP_KERNEL); > > + if (!jtag) > > + return NULL; > > If you set ARCH_DMA_MINALIGN to 1 when not defined, what is this > achieving that kmalloc() is not already doing? > Removed ARCH_DMA_MINALIGN > > + > > + jtag->ops = ops; > > + return jtag; > > +} > > +EXPORT_SYMBOL_GPL(jtag_alloc); > > + > > +void jtag_free(struct jtag *jtag) > > +{ > > + kfree(jtag); > > +} > > +EXPORT_SYMBOL_GPL(jtag_free); > > + > > +int jtag_register(struct jtag *jtag) > > +{ > > + char *name; > > + int err; > > + int id; > > + > > + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL); > > + if (id < 0) > > + return id; > > + > > + jtag->id = id; > > + > > + name = kzalloc(MAX_JTAG_NAME_LEN, GFP_KERNEL); > > + if (!name) { > > + err = -ENOMEM; > > + goto err_jtag_alloc; > > + } > > Can't you use jtag->miscdev.dev here to simplify the allocation error > handling? > How, what you mean? > > +#ifndef ARCH_DMA_MINALIGN > > +#define ARCH_DMA_MINALIGN 1 > > +#endif > > Why? > Not used now, Deleted > > +#endif /* __JTAG_H */ > > diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h new > > file mode 100644 index 0000000..cda2520 > > --- /dev/null > > +++ b/include/uapi/linux/jtag.h > > [snip] > > > +struct jtag_xfer { > > + __u8 type; > > + __u8 direction; > > Can these two be an enum referring to what you defined earlier? > Greg KH <gregkh@linuxfoundation.org> say: "All structures that cross the user/kernel boundry have to use the __ type variables. No "unsigned char", it has to be "__u8", no "unsigned short", it has to be "__u16", and so on. Also, watch out for your enumerated types, what's the packing end up looking like on these structures? Have you verified it works with a 64bit kernel and 32bit userspace all correctly?" So I use __u8 type instead of enum to avoid errors while crossing 64bit kernel and 32bit userspace. > > + __u8 endstate; > > + __u32 length; > > + __u64 tdio; > > +}; > -- > Florian Thaks.
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 3e3fdae..1af2508 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -321,6 +321,8 @@ Code Seq#(hex) Include File Comments 0xB0 all RATIO devices in development: <mailto:vgo@ratio.de> 0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca> +0xB2 00-0f linux/jtag.h JTAG driver + <mailto:oleksandrs@mellanox.com> 0xB3 00 linux/mmc/ioctl.h 0xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> diff --git a/MAINTAINERS b/MAINTAINERS index 205d397..dfcf49c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7292,6 +7292,16 @@ L: linux-serial@vger.kernel.org S: Maintained F: drivers/tty/serial/jsm/ +JTAG SUBSYSTEM +M: Oleksandr Shamray <oleksandrs@mellanox.com> +M: Vadim Pasternak <vadimp@mellanox.com> +S: Maintained +F: include/linux/jtag.h +F: include/uapi/linux/jtag.h +F: drivers/jtag/ +F: Documentation/devicetree/bindings/jtag/ +F: Documentation/ABI/testing/jtag-cdev + K10TEMP HARDWARE MONITORING DRIVER M: Clemens Ladisch <clemens@ladisch.de> L: linux-hwmon@vger.kernel.org diff --git a/drivers/Kconfig b/drivers/Kconfig index 505c676..2214678 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -208,4 +208,6 @@ source "drivers/tee/Kconfig" source "drivers/mux/Kconfig" +source "drivers/jtag/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index dfdcda0..6a2059b 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -182,3 +182,4 @@ obj-$(CONFIG_FPGA) += fpga/ obj-$(CONFIG_FSI) += fsi/ obj-$(CONFIG_TEE) += tee/ obj-$(CONFIG_MULTIPLEXER) += mux/ +obj-$(CONFIG_JTAG) += jtag/ diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig new file mode 100644 index 0000000..0fad1a3 --- /dev/null +++ b/drivers/jtag/Kconfig @@ -0,0 +1,16 @@ +menuconfig JTAG + tristate "JTAG support" + ---help--- + This provides basic core functionality support for jtag class devices + Hardware equipped with JTAG microcontroller which can be built + on top of this drivers. Driver exposes the set of IOCTL to the + user space for: + SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan); + SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan); + RUNTEST (Forces IEEE 1149.1 bus to a run state for specified + number of clocks). + + If you want this support, you should say Y here. + + To compile this driver as a module, choose M here: the module will + be called jtag. diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile new file mode 100644 index 0000000..af37493 --- /dev/null +++ b/drivers/jtag/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_JTAG) += jtag.o diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c new file mode 100644 index 0000000..39cbce9 --- /dev/null +++ b/drivers/jtag/jtag.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0 +// drivers/jtag/jtag.c +// +// Copyright (c) 2017 Mellanox Technologies. All rights reserved. +// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com> + +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/jtag.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/rtnetlink.h> +#include <linux/spinlock.h> +#include <linux/types.h> +#include <uapi/linux/jtag.h> + +#define JTAG_NAME "jtag0" +#define MAX_JTAG_NAME_LEN (sizeof("jtag") + 5) + +struct jtag { + struct miscdevice miscdev; + struct device *dev; + const struct jtag_ops *ops; + int id; + bool opened; + struct mutex open_lock; + unsigned long priv[0]; +}; + +static DEFINE_IDA(jtag_ida); + +void *jtag_priv(struct jtag *jtag) +{ + return jtag->priv; +} +EXPORT_SYMBOL_GPL(jtag_priv); + +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct jtag *jtag = file->private_data; + struct jtag_run_test_idle idle; + struct jtag_xfer xfer; + u8 *xfer_data; + u32 data_size; + u32 value; + int err; + + if (!arg) + return -EINVAL; + + switch (cmd) { + case JTAG_GIOCFREQ: + + if (jtag->ops->freq_get) + err = jtag->ops->freq_get(jtag, &value); + else + err = -EOPNOTSUPP; + if (err) + break; + + if (put_user(value, (__u32 *)arg)) + err = -EFAULT; + break; + + case JTAG_SIOCFREQ: + if (get_user(value, (__u32 *)arg)) + return -EFAULT; + if (value == 0) + return -EINVAL; + + if (jtag->ops->freq_set) + err = jtag->ops->freq_set(jtag, value); + else + err = -EOPNOTSUPP; + break; + + case JTAG_IOCRUNTEST: + if (copy_from_user(&idle, (void *)arg, + sizeof(struct jtag_run_test_idle))) + return -EFAULT; + + if (idle.endstate > JTAG_STATE_PAUSEDR) + return -EINVAL; + + if (jtag->ops->idle) + err = jtag->ops->idle(jtag, &idle); + else + err = -EOPNOTSUPP; + break; + + case JTAG_IOCXFER: + if (copy_from_user(&xfer, (void *)arg, + sizeof(struct jtag_xfer))) + return -EFAULT; + + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN) + return -EINVAL; + + if (xfer.type > JTAG_SDR_XFER) + return -EINVAL; + + if (xfer.direction > JTAG_WRITE_XFER) + return -EINVAL; + + if (xfer.endstate > JTAG_STATE_PAUSEDR) + return -EINVAL; + + data_size = DIV_ROUND_UP(xfer.length, BITS_PER_BYTE); + xfer_data = memdup_user(u64_to_user_ptr(xfer.tdio), data_size); + + if (!xfer_data) + return -EFAULT; + + if (jtag->ops->xfer) { + err = jtag->ops->xfer(jtag, &xfer, xfer_data); + } else { + kfree(xfer_data); + return -EOPNOTSUPP; + } + + if (err) { + kfree(xfer_data); + return -EFAULT; + } + + err = copy_to_user(u64_to_user_ptr(xfer.tdio), + (void *)(xfer_data), data_size); + + if (err) { + kfree(xfer_data); + return -EFAULT; + } + + kfree(xfer_data); + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer))) + return -EFAULT; + break; + + case JTAG_GIOCSTATUS: + if (jtag->ops->status_get) + err = jtag->ops->status_get(jtag, &value); + else + err = -EOPNOTSUPP; + if (err) + break; + + err = put_user(value, (__u32 *)arg); + if (err) + err = -EFAULT; + break; + case JTAG_SIOCMODE: + if (get_user(value, (__u32 *)arg)) + return -EFAULT; + if (value == 0) + return -EINVAL; + + if (jtag->ops->mode_set) + err = jtag->ops->mode_set(jtag, value); + else + err = -EOPNOTSUPP; + break; + + default: + return -EINVAL; + } + return err; +} + +static int jtag_open(struct inode *inode, struct file *file) +{ + struct jtag *jtag = container_of(file->private_data, struct jtag, + miscdev); + + if (mutex_lock_interruptible(&jtag->open_lock)) + return -ERESTARTSYS; + + if (jtag->opened) { + mutex_unlock(&jtag->open_lock); + return -EINVAL; + } + + nonseekable_open(inode, file); + file->private_data = jtag; + jtag->opened = true; + mutex_unlock(&jtag->open_lock); + return 0; +} + +static int jtag_release(struct inode *inode, struct file *file) +{ + struct jtag *jtag = file->private_data; + + mutex_lock(&jtag->open_lock); + jtag->opened = false; + mutex_unlock(&jtag->open_lock); + return 0; +} + +static const struct file_operations jtag_fops = { + .owner = THIS_MODULE, + .open = jtag_open, + .release = jtag_release, + .llseek = noop_llseek, + .unlocked_ioctl = jtag_ioctl, +}; + +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops) +{ + struct jtag *jtag; + + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN), + GFP_KERNEL); + if (!jtag) + return NULL; + + jtag->ops = ops; + return jtag; +} +EXPORT_SYMBOL_GPL(jtag_alloc); + +void jtag_free(struct jtag *jtag) +{ + kfree(jtag); +} +EXPORT_SYMBOL_GPL(jtag_free); + +int jtag_register(struct jtag *jtag) +{ + char *name; + int err; + int id; + + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL); + if (id < 0) + return id; + + jtag->id = id; + + name = kzalloc(MAX_JTAG_NAME_LEN, GFP_KERNEL); + if (!name) { + err = -ENOMEM; + goto err_jtag_alloc; + } + + err = snprintf(name, MAX_JTAG_NAME_LEN, "jtag%d", id); + if (err < 0) + goto err_jtag_name; + + mutex_init(&jtag->open_lock); + jtag->miscdev.fops = &jtag_fops; + jtag->miscdev.minor = MISC_DYNAMIC_MINOR; + jtag->miscdev.name = name; + + err = misc_register(&jtag->miscdev); + if (err) + dev_err(jtag->dev, "Unable to register device\n"); + else + return 0; + jtag->opened = false; + +err_jtag_name: + kfree(name); +err_jtag_alloc: + ida_simple_remove(&jtag_ida, id); + return err; +} +EXPORT_SYMBOL_GPL(jtag_register); + +void jtag_unregister(struct jtag *jtag) +{ + misc_deregister(&jtag->miscdev); + kfree(jtag->miscdev.name); + ida_simple_remove(&jtag_ida, jtag->id); +} +EXPORT_SYMBOL_GPL(jtag_unregister); + +static void __exit jtag_exit(void) +{ + ida_destroy(&jtag_ida); +} + +module_exit(jtag_exit); + +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>"); +MODULE_DESCRIPTION("Generic jtag support"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/jtag.h b/include/linux/jtag.h new file mode 100644 index 0000000..312c641 --- /dev/null +++ b/include/linux/jtag.h @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +// include/linux/jtag.h - JTAG class driver +// +// Copyright (c) 2017 Mellanox Technologies. All rights reserved. +// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com> + +#ifndef __JTAG_H +#define __JTAG_H + +#include <uapi/linux/jtag.h> + +#ifndef ARCH_DMA_MINALIGN +#define ARCH_DMA_MINALIGN 1 +#endif + +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg) + +#define JTAG_MAX_XFER_DATA_LEN 65535 + +struct jtag; +/** + * struct jtag_ops - callbacks for jtag control functions: + * + * @freq_get: get frequency function. Filled by device driver + * @freq_set: set frequency function. Filled by device driver + * @status_get: set status function. Filled by device driver + * @idle: set JTAG to idle state function. Filled by device driver + * @xfer: send JTAG xfer function. Filled by device driver + */ +struct jtag_ops { + int (*freq_get)(struct jtag *jtag, u32 *freq); + int (*freq_set)(struct jtag *jtag, u32 freq); + int (*status_get)(struct jtag *jtag, u32 *state); + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle); + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer, u8 *xfer_data); + int (*mode_set)(struct jtag *jtag, u32 mode_mask); +}; + +void *jtag_priv(struct jtag *jtag); +int jtag_register(struct jtag *jtag); +void jtag_unregister(struct jtag *jtag); +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops); +void jtag_free(struct jtag *jtag); + +#endif /* __JTAG_H */ diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h new file mode 100644 index 0000000..cda2520 --- /dev/null +++ b/include/uapi/linux/jtag.h @@ -0,0 +1,104 @@ +// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note +// include/uapi/linux/jtag.h - JTAG class driver uapi +// +// Copyright (c) 2017 Mellanox Technologies. All rights reserved. +// Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com> + +#ifndef __UAPI_LINUX_JTAG_H +#define __UAPI_LINUX_JTAG_H + +#include <linux/types.h> +/* + * JTAG_XFER_HW_MODE: JTAG hardware mode. Used to set HW drived or bitbang + * mode. This is bitmask param of ioctl JTAG_SIOCMODE command + */ +#define JTAG_XFER_HW_MODE 1 + +/** + * enum jtag_endstate: + * + * @JTAG_STATE_IDLE: JTAG state machine IDLE state + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state + */ +enum jtag_endstate { + JTAG_STATE_IDLE, + JTAG_STATE_PAUSEIR, + JTAG_STATE_PAUSEDR, +}; + +/** + * enum jtag_xfer_type: + * + * @JTAG_SIR_XFER: SIR transfer + * @JTAG_SDR_XFER: SDR transfer + */ +enum jtag_xfer_type { + JTAG_SIR_XFER, + JTAG_SDR_XFER, +}; + +/** + * enum jtag_xfer_direction: + * + * @JTAG_READ_XFER: read transfer + * @JTAG_WRITE_XFER: write transfer + */ +enum jtag_xfer_direction { + JTAG_READ_XFER, + JTAG_WRITE_XFER, +}; + +/** + * struct jtag_run_test_idle - forces JTAG state machine to + * RUN_TEST/IDLE state + * + * @reset: 0 - run IDLE/PAUSE from current state + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE + * @end: completion flag + * @tck: clock counter + * + * Structure represents interface to JTAG device for jtag idle + * execution. + */ +struct jtag_run_test_idle { + __u8 reset; + __u8 endstate; + __u8 tck; +}; + +/** + * struct jtag_xfer - jtag xfer: + * + * @type: transfer type + * @direction: xfer direction + * @length: xfer bits len + * @tdio : xfer data array + * @endir: xfer end state + * + * Structure represents interface to JTAG device for jtag sdr xfer + * execution. + */ +struct jtag_xfer { + __u8 type; + __u8 direction; + __u8 endstate; + __u32 length; + __u64 tdio; +}; + +/* ioctl interface */ +#define __JTAG_IOCTL_MAGIC 0xb2 + +#define JTAG_IOCRUNTEST _IOW(__JTAG_IOCTL_MAGIC, 0,\ + struct jtag_run_test_idle) +#define JTAG_SIOCFREQ _IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int) +#define JTAG_GIOCFREQ _IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int) +#define JTAG_IOCXFER _IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer) +#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate) +#define JTAG_SIOCMODE _IOW(__JTAG_IOCTL_MAGIC, 5, unsigned int) + +#define JTAG_FIRST_MINOR 0 +#define JTAG_MAX_DEVICES 32 + +#endif /* __UAPI_LINUX_JTAG_H */