mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 11:56:40 +07:00
142956af52
Use of ptrdiff_t in places like - if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len)) + if (!access_ok(VERIFY_WRITE, (u8 __user *) + (ptrdiff_t) u_tmp->rx_buf, + u_tmp->len)) is wrong; for one thing, it's a bad C (it's what uintptr_t is for; in general we are not even promised that ptrdiff_t is large enough to hold a pointer, just enough to hold a difference between two pointers within the same object). For another, it confuses the fsck out of sparse. Use unsigned long or uintptr_t instead. There are several places misusing ptrdiff_t; fixed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
597 lines
15 KiB
C
597 lines
15 KiB
C
/*
|
|
* spidev.c -- simple synchronous userspace interface to SPI devices
|
|
*
|
|
* Copyright (C) 2006 SWAPP
|
|
* Andrea Paterniani <a.paterniani@swapp-eng.it>
|
|
* Copyright (C) 2007 David Brownell (simplification, cleanup)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/ioctl.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/device.h>
|
|
#include <linux/list.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/spi/spi.h>
|
|
#include <linux/spi/spidev.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
|
|
|
|
/*
|
|
* This supports acccess to SPI devices using normal userspace I/O calls.
|
|
* Note that while traditional UNIX/POSIX I/O semantics are half duplex,
|
|
* and often mask message boundaries, full SPI support requires full duplex
|
|
* transfers. There are several kinds of of internal message boundaries to
|
|
* handle chipselect management and other protocol options.
|
|
*
|
|
* SPI has a character major number assigned. We allocate minor numbers
|
|
* dynamically using a bitmask. You must use hotplug tools, such as udev
|
|
* (or mdev with busybox) to create and destroy the /dev/spidevB.C device
|
|
* nodes, since there is no fixed association of minor numbers with any
|
|
* particular SPI bus or device.
|
|
*/
|
|
#define SPIDEV_MAJOR 153 /* assigned */
|
|
#define N_SPI_MINORS 32 /* ... up to 256 */
|
|
|
|
static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG];
|
|
|
|
|
|
/* Bit masks for spi_device.mode management. Note that incorrect
|
|
* settings for CS_HIGH and 3WIRE can cause *lots* of trouble for other
|
|
* devices on a shared bus: CS_HIGH, because this device will be
|
|
* active when it shouldn't be; 3WIRE, because when active it won't
|
|
* behave as it should.
|
|
*
|
|
* REVISIT should changing those two modes be privileged?
|
|
*/
|
|
#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
|
|
| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP)
|
|
|
|
struct spidev_data {
|
|
struct device dev;
|
|
struct spi_device *spi;
|
|
struct list_head device_entry;
|
|
|
|
struct mutex buf_lock;
|
|
unsigned users;
|
|
u8 *buffer;
|
|
};
|
|
|
|
static LIST_HEAD(device_list);
|
|
static DEFINE_MUTEX(device_list_lock);
|
|
|
|
static unsigned bufsiz = 4096;
|
|
module_param(bufsiz, uint, S_IRUGO);
|
|
MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
/* Read-only message with current device setup */
|
|
static ssize_t
|
|
spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
|
|
{
|
|
struct spidev_data *spidev;
|
|
struct spi_device *spi;
|
|
ssize_t status = 0;
|
|
|
|
/* chipselect only toggles at start or end of operation */
|
|
if (count > bufsiz)
|
|
return -EMSGSIZE;
|
|
|
|
spidev = filp->private_data;
|
|
spi = spidev->spi;
|
|
|
|
mutex_lock(&spidev->buf_lock);
|
|
status = spi_read(spi, spidev->buffer, count);
|
|
if (status == 0) {
|
|
unsigned long missing;
|
|
|
|
missing = copy_to_user(buf, spidev->buffer, count);
|
|
if (count && missing == count)
|
|
status = -EFAULT;
|
|
else
|
|
status = count - missing;
|
|
}
|
|
mutex_unlock(&spidev->buf_lock);
|
|
|
|
return status;
|
|
}
|
|
|
|
/* Write-only message with current device setup */
|
|
static ssize_t
|
|
spidev_write(struct file *filp, const char __user *buf,
|
|
size_t count, loff_t *f_pos)
|
|
{
|
|
struct spidev_data *spidev;
|
|
struct spi_device *spi;
|
|
ssize_t status = 0;
|
|
unsigned long missing;
|
|
|
|
/* chipselect only toggles at start or end of operation */
|
|
if (count > bufsiz)
|
|
return -EMSGSIZE;
|
|
|
|
spidev = filp->private_data;
|
|
spi = spidev->spi;
|
|
|
|
mutex_lock(&spidev->buf_lock);
|
|
missing = copy_from_user(spidev->buffer, buf, count);
|
|
if (missing == 0) {
|
|
status = spi_write(spi, spidev->buffer, count);
|
|
if (status == 0)
|
|
status = count;
|
|
} else
|
|
status = -EFAULT;
|
|
mutex_unlock(&spidev->buf_lock);
|
|
|
|
return status;
|
|
}
|
|
|
|
static int spidev_message(struct spidev_data *spidev,
|
|
struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
|
|
{
|
|
struct spi_message msg;
|
|
struct spi_transfer *k_xfers;
|
|
struct spi_transfer *k_tmp;
|
|
struct spi_ioc_transfer *u_tmp;
|
|
struct spi_device *spi = spidev->spi;
|
|
unsigned n, total;
|
|
u8 *buf;
|
|
int status = -EFAULT;
|
|
|
|
spi_message_init(&msg);
|
|
k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL);
|
|
if (k_xfers == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* Construct spi_message, copying any tx data to bounce buffer.
|
|
* We walk the array of user-provided transfers, using each one
|
|
* to initialize a kernel version of the same transfer.
|
|
*/
|
|
mutex_lock(&spidev->buf_lock);
|
|
buf = spidev->buffer;
|
|
total = 0;
|
|
for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
|
|
n;
|
|
n--, k_tmp++, u_tmp++) {
|
|
k_tmp->len = u_tmp->len;
|
|
|
|
total += k_tmp->len;
|
|
if (total > bufsiz) {
|
|
status = -EMSGSIZE;
|
|
goto done;
|
|
}
|
|
|
|
if (u_tmp->rx_buf) {
|
|
k_tmp->rx_buf = buf;
|
|
if (!access_ok(VERIFY_WRITE, (u8 __user *)
|
|
(uintptr_t) u_tmp->rx_buf,
|
|
u_tmp->len))
|
|
goto done;
|
|
}
|
|
if (u_tmp->tx_buf) {
|
|
k_tmp->tx_buf = buf;
|
|
if (copy_from_user(buf, (const u8 __user *)
|
|
(uintptr_t) u_tmp->tx_buf,
|
|
u_tmp->len))
|
|
goto done;
|
|
}
|
|
buf += k_tmp->len;
|
|
|
|
k_tmp->cs_change = !!u_tmp->cs_change;
|
|
k_tmp->bits_per_word = u_tmp->bits_per_word;
|
|
k_tmp->delay_usecs = u_tmp->delay_usecs;
|
|
k_tmp->speed_hz = u_tmp->speed_hz;
|
|
#ifdef VERBOSE
|
|
dev_dbg(&spi->dev,
|
|
" xfer len %zd %s%s%s%dbits %u usec %uHz\n",
|
|
u_tmp->len,
|
|
u_tmp->rx_buf ? "rx " : "",
|
|
u_tmp->tx_buf ? "tx " : "",
|
|
u_tmp->cs_change ? "cs " : "",
|
|
u_tmp->bits_per_word ? : spi->bits_per_word,
|
|
u_tmp->delay_usecs,
|
|
u_tmp->speed_hz ? : spi->max_speed_hz);
|
|
#endif
|
|
spi_message_add_tail(k_tmp, &msg);
|
|
}
|
|
|
|
status = spi_sync(spi, &msg);
|
|
if (status < 0)
|
|
goto done;
|
|
|
|
/* copy any rx data out of bounce buffer */
|
|
buf = spidev->buffer;
|
|
for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
|
|
if (u_tmp->rx_buf) {
|
|
if (__copy_to_user((u8 __user *)
|
|
(uintptr_t) u_tmp->rx_buf, buf,
|
|
u_tmp->len)) {
|
|
status = -EFAULT;
|
|
goto done;
|
|
}
|
|
}
|
|
buf += u_tmp->len;
|
|
}
|
|
status = total;
|
|
|
|
done:
|
|
mutex_unlock(&spidev->buf_lock);
|
|
kfree(k_xfers);
|
|
return status;
|
|
}
|
|
|
|
static int
|
|
spidev_ioctl(struct inode *inode, struct file *filp,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
int err = 0;
|
|
int retval = 0;
|
|
struct spidev_data *spidev;
|
|
struct spi_device *spi;
|
|
u32 tmp;
|
|
unsigned n_ioc;
|
|
struct spi_ioc_transfer *ioc;
|
|
|
|
/* Check type and command number */
|
|
if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
|
|
return -ENOTTY;
|
|
|
|
/* Check access direction once here; don't repeat below.
|
|
* IOC_DIR is from the user perspective, while access_ok is
|
|
* from the kernel perspective; so they look reversed.
|
|
*/
|
|
if (_IOC_DIR(cmd) & _IOC_READ)
|
|
err = !access_ok(VERIFY_WRITE,
|
|
(void __user *)arg, _IOC_SIZE(cmd));
|
|
if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE)
|
|
err = !access_ok(VERIFY_READ,
|
|
(void __user *)arg, _IOC_SIZE(cmd));
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
spidev = filp->private_data;
|
|
spi = spidev->spi;
|
|
|
|
switch (cmd) {
|
|
/* read requests */
|
|
case SPI_IOC_RD_MODE:
|
|
retval = __put_user(spi->mode & SPI_MODE_MASK,
|
|
(__u8 __user *)arg);
|
|
break;
|
|
case SPI_IOC_RD_LSB_FIRST:
|
|
retval = __put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0,
|
|
(__u8 __user *)arg);
|
|
break;
|
|
case SPI_IOC_RD_BITS_PER_WORD:
|
|
retval = __put_user(spi->bits_per_word, (__u8 __user *)arg);
|
|
break;
|
|
case SPI_IOC_RD_MAX_SPEED_HZ:
|
|
retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg);
|
|
break;
|
|
|
|
/* write requests */
|
|
case SPI_IOC_WR_MODE:
|
|
retval = __get_user(tmp, (u8 __user *)arg);
|
|
if (retval == 0) {
|
|
u8 save = spi->mode;
|
|
|
|
if (tmp & ~SPI_MODE_MASK) {
|
|
retval = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
tmp |= spi->mode & ~SPI_MODE_MASK;
|
|
spi->mode = (u8)tmp;
|
|
retval = spi_setup(spi);
|
|
if (retval < 0)
|
|
spi->mode = save;
|
|
else
|
|
dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
|
|
}
|
|
break;
|
|
case SPI_IOC_WR_LSB_FIRST:
|
|
retval = __get_user(tmp, (__u8 __user *)arg);
|
|
if (retval == 0) {
|
|
u8 save = spi->mode;
|
|
|
|
if (tmp)
|
|
spi->mode |= SPI_LSB_FIRST;
|
|
else
|
|
spi->mode &= ~SPI_LSB_FIRST;
|
|
retval = spi_setup(spi);
|
|
if (retval < 0)
|
|
spi->mode = save;
|
|
else
|
|
dev_dbg(&spi->dev, "%csb first\n",
|
|
tmp ? 'l' : 'm');
|
|
}
|
|
break;
|
|
case SPI_IOC_WR_BITS_PER_WORD:
|
|
retval = __get_user(tmp, (__u8 __user *)arg);
|
|
if (retval == 0) {
|
|
u8 save = spi->bits_per_word;
|
|
|
|
spi->bits_per_word = tmp;
|
|
retval = spi_setup(spi);
|
|
if (retval < 0)
|
|
spi->bits_per_word = save;
|
|
else
|
|
dev_dbg(&spi->dev, "%d bits per word\n", tmp);
|
|
}
|
|
break;
|
|
case SPI_IOC_WR_MAX_SPEED_HZ:
|
|
retval = __get_user(tmp, (__u32 __user *)arg);
|
|
if (retval == 0) {
|
|
u32 save = spi->max_speed_hz;
|
|
|
|
spi->max_speed_hz = tmp;
|
|
retval = spi_setup(spi);
|
|
if (retval < 0)
|
|
spi->max_speed_hz = save;
|
|
else
|
|
dev_dbg(&spi->dev, "%d Hz (max)\n", tmp);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
/* segmented and/or full-duplex I/O request */
|
|
if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
|
|
|| _IOC_DIR(cmd) != _IOC_WRITE)
|
|
return -ENOTTY;
|
|
|
|
tmp = _IOC_SIZE(cmd);
|
|
if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) {
|
|
retval = -EINVAL;
|
|
break;
|
|
}
|
|
n_ioc = tmp / sizeof(struct spi_ioc_transfer);
|
|
if (n_ioc == 0)
|
|
break;
|
|
|
|
/* copy into scratch area */
|
|
ioc = kmalloc(tmp, GFP_KERNEL);
|
|
if (!ioc) {
|
|
retval = -ENOMEM;
|
|
break;
|
|
}
|
|
if (__copy_from_user(ioc, (void __user *)arg, tmp)) {
|
|
kfree(ioc);
|
|
retval = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
/* translate to spi_message, execute */
|
|
retval = spidev_message(spidev, ioc, n_ioc);
|
|
kfree(ioc);
|
|
break;
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
static int spidev_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct spidev_data *spidev;
|
|
int status = -ENXIO;
|
|
|
|
mutex_lock(&device_list_lock);
|
|
|
|
list_for_each_entry(spidev, &device_list, device_entry) {
|
|
if (spidev->dev.devt == inode->i_rdev) {
|
|
status = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (status == 0) {
|
|
if (!spidev->buffer) {
|
|
spidev->buffer = kmalloc(bufsiz, GFP_KERNEL);
|
|
if (!spidev->buffer) {
|
|
dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
|
|
status = -ENOMEM;
|
|
}
|
|
}
|
|
if (status == 0) {
|
|
spidev->users++;
|
|
filp->private_data = spidev;
|
|
nonseekable_open(inode, filp);
|
|
}
|
|
} else
|
|
pr_debug("spidev: nothing for minor %d\n", iminor(inode));
|
|
|
|
mutex_unlock(&device_list_lock);
|
|
return status;
|
|
}
|
|
|
|
static int spidev_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct spidev_data *spidev;
|
|
int status = 0;
|
|
|
|
mutex_lock(&device_list_lock);
|
|
spidev = filp->private_data;
|
|
filp->private_data = NULL;
|
|
spidev->users--;
|
|
if (!spidev->users) {
|
|
kfree(spidev->buffer);
|
|
spidev->buffer = NULL;
|
|
}
|
|
mutex_unlock(&device_list_lock);
|
|
|
|
return status;
|
|
}
|
|
|
|
static struct file_operations spidev_fops = {
|
|
.owner = THIS_MODULE,
|
|
/* REVISIT switch to aio primitives, so that userspace
|
|
* gets more complete API coverage. It'll simplify things
|
|
* too, except for the locking.
|
|
*/
|
|
.write = spidev_write,
|
|
.read = spidev_read,
|
|
.ioctl = spidev_ioctl,
|
|
.open = spidev_open,
|
|
.release = spidev_release,
|
|
};
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
/* The main reason to have this class is to make mdev/udev create the
|
|
* /dev/spidevB.C character device nodes exposing our userspace API.
|
|
* It also simplifies memory management.
|
|
*/
|
|
|
|
static void spidev_classdev_release(struct device *dev)
|
|
{
|
|
struct spidev_data *spidev;
|
|
|
|
spidev = container_of(dev, struct spidev_data, dev);
|
|
kfree(spidev);
|
|
}
|
|
|
|
static struct class spidev_class = {
|
|
.name = "spidev",
|
|
.owner = THIS_MODULE,
|
|
.dev_release = spidev_classdev_release,
|
|
};
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
static int spidev_probe(struct spi_device *spi)
|
|
{
|
|
struct spidev_data *spidev;
|
|
int status;
|
|
unsigned long minor;
|
|
|
|
/* Allocate driver data */
|
|
spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
|
|
if (!spidev)
|
|
return -ENOMEM;
|
|
|
|
/* Initialize the driver data */
|
|
spidev->spi = spi;
|
|
mutex_init(&spidev->buf_lock);
|
|
|
|
INIT_LIST_HEAD(&spidev->device_entry);
|
|
|
|
/* If we can allocate a minor number, hook up this device.
|
|
* Reusing minors is fine so long as udev or mdev is working.
|
|
*/
|
|
mutex_lock(&device_list_lock);
|
|
minor = find_first_zero_bit(minors, N_SPI_MINORS);
|
|
if (minor < N_SPI_MINORS) {
|
|
spidev->dev.parent = &spi->dev;
|
|
spidev->dev.class = &spidev_class;
|
|
spidev->dev.devt = MKDEV(SPIDEV_MAJOR, minor);
|
|
snprintf(spidev->dev.bus_id, sizeof spidev->dev.bus_id,
|
|
"spidev%d.%d",
|
|
spi->master->bus_num, spi->chip_select);
|
|
status = device_register(&spidev->dev);
|
|
} else {
|
|
dev_dbg(&spi->dev, "no minor number available!\n");
|
|
status = -ENODEV;
|
|
}
|
|
if (status == 0) {
|
|
set_bit(minor, minors);
|
|
dev_set_drvdata(&spi->dev, spidev);
|
|
list_add(&spidev->device_entry, &device_list);
|
|
}
|
|
mutex_unlock(&device_list_lock);
|
|
|
|
if (status != 0)
|
|
kfree(spidev);
|
|
|
|
return status;
|
|
}
|
|
|
|
static int spidev_remove(struct spi_device *spi)
|
|
{
|
|
struct spidev_data *spidev = dev_get_drvdata(&spi->dev);
|
|
|
|
mutex_lock(&device_list_lock);
|
|
|
|
list_del(&spidev->device_entry);
|
|
dev_set_drvdata(&spi->dev, NULL);
|
|
clear_bit(MINOR(spidev->dev.devt), minors);
|
|
device_unregister(&spidev->dev);
|
|
|
|
mutex_unlock(&device_list_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct spi_driver spidev_spi = {
|
|
.driver = {
|
|
.name = "spidev",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.probe = spidev_probe,
|
|
.remove = __devexit_p(spidev_remove),
|
|
|
|
/* NOTE: suspend/resume methods are not necessary here.
|
|
* We don't do anything except pass the requests to/from
|
|
* the underlying controller. The refrigerator handles
|
|
* most issues; the controller driver handles the rest.
|
|
*/
|
|
};
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
static int __init spidev_init(void)
|
|
{
|
|
int status;
|
|
|
|
/* Claim our 256 reserved device numbers. Then register a class
|
|
* that will key udev/mdev to add/remove /dev nodes. Last, register
|
|
* the driver which manages those device numbers.
|
|
*/
|
|
BUILD_BUG_ON(N_SPI_MINORS > 256);
|
|
status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops);
|
|
if (status < 0)
|
|
return status;
|
|
|
|
status = class_register(&spidev_class);
|
|
if (status < 0) {
|
|
unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
|
|
return status;
|
|
}
|
|
|
|
status = spi_register_driver(&spidev_spi);
|
|
if (status < 0) {
|
|
class_unregister(&spidev_class);
|
|
unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
|
|
}
|
|
return status;
|
|
}
|
|
module_init(spidev_init);
|
|
|
|
static void __exit spidev_exit(void)
|
|
{
|
|
spi_unregister_driver(&spidev_spi);
|
|
class_unregister(&spidev_class);
|
|
unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
|
|
}
|
|
module_exit(spidev_exit);
|
|
|
|
MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
|
|
MODULE_DESCRIPTION("User mode SPI device interface");
|
|
MODULE_LICENSE("GPL");
|