- 根目录:
- drivers
- hid
- hidraw.c
/*
* HID raw devices, giving access to raw HID events.
*
* In comparison to hiddev, this device does not process the
* hid events at all (no parsing, no lookups). This lets applications
* to work on raw hid events as they want to, and avoids a need to
* use a transport-specific userspace libhid/libusb libraries.
*
* Copyright (c) 2007 Jiri Kosina
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/hidraw.h>
static int hidraw_major;
static struct cdev hidraw_cdev;
static struct class *hidraw_class;
static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
static DEFINE_MUTEX(minors_lock);
static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
struct hidraw_list *list = file->private_data;
int ret = 0, len;
DECLARE_WAITQUEUE(wait, current);
mutex_lock(&list->read_mutex);
while (ret == 0) {
if (list->head == list->tail) {
add_wait_queue(&list->hidraw->wait, &wait);
set_current_state(TASK_INTERRUPTIBLE);
while (list->head == list->tail) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
if (!list->hidraw->exist) {
ret = -EIO;
break;
}
/* allow O_NONBLOCK to work well from other threads */
mutex_unlock(&list->read_mutex);
schedule();
mutex_lock(&list->read_mutex);
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&list->hidraw->wait, &wait);
}
if (ret)
goto out;
len = list->buffer[list->tail].len > count ?
count : list->buffer[list->tail].len;
if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
ret = -EFAULT;
goto out;
}
ret = len;
kfree(list->buffer[list->tail].value);
list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
}
out:
mutex_unlock(&list->read_mutex);
return ret;
}
/* The first byte is expected to be a report number.
* This function is to be called with the minors_lock mutex held */
static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
{
unsigned int minor = iminor(file->f_path.dentry->d_inode);
struct hid_device *dev;
__u8 *buf;
int ret = 0;
if (!hidraw_table[minor]) {
ret = -ENODEV;
goto out;
}
dev = hidraw_table[minor]->hid;
if (!dev->hid_output_raw_report) {
ret = -ENODEV;
goto out;
}
if (count > HID_MAX_BUFFER_SIZE) {
hid_warn(dev, "pid %d passed too large report\n",
task_pid_nr(current));
ret = -EINVAL;
goto out;
}
if (count < 2) {
hid_warn(dev, "pid %d passed too short report\n",
task_pid_nr(current));
ret = -EINVAL;
goto out;
}
buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto out;
}
if (copy_from_user(buf, buffer, count)) {
ret = -EFAULT;
goto out_free;
}
ret = dev->hid_output_raw_report(dev, buf, count, report_type);
out_free:
kfree(buf);
out:
return ret;
}
/* the first byte is expected to be a report number */
static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
ssize_t ret;
mutex_lock(&minors_lock);
ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
mutex_unlock(&minors_lock);
return ret;
}
/* This function performs a Get_Report transfer over the control endpoint
* per section 7.2.1 of the HID specification, version 1.1. The first byte
* of buffer is the report number to request, or 0x0 if the defice does not
* use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
* or HID_INPUT_REPORT. This function is to be called with the minors_lock
* mutex held. */
static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
{
unsigned int minor = iminor(file->f_path.dentry->d_inode);
struct hid_device *dev;
__u8 *buf;
int ret = 0, len;
unsigned char report_number;
dev = hidraw_table[minor]->hid;
if (!dev->hid_get_raw_report) {
ret = -ENODEV;
goto out;
}
if (count > HID_MAX_BUFFER_SIZE) {
printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
task_pid_nr(current));
ret = -EINVAL;
goto out;
}
if (count < 2) {
printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
task_pid_nr(current));
ret = -EINVAL;
goto out;
}
buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto out;
}
/* Read the first byte from the user. This is the report number,
* which is passed to dev->hid_get_raw_report(). */
if (copy_from_user(&report_number, buffer, 1)) {
ret = -EFAULT;
goto out_free;
}
ret = dev->hid_get_raw_report(dev, report_number, buf, count, report_type);
if (ret < 0)
goto out_free;
len = (ret < count) ? ret : count;
if (copy_to_user(buffer, buf, len)) {
ret = -EFAULT;
goto out_free;
}
ret = len;
out_free:
kfree(buf);
out:
return ret;
}
static unsigned int hidraw_poll(struct file *file, poll_table *wait)
{
struct hidraw_list *list = file->private_data;
poll_wait(file, &list->hidraw->wait, wait);
if (list->head != list->tail)
return POLLIN | POLLRDNORM;
if (!list->hidraw->exist)
return POLLERR | POLLHUP;
return 0;
}
static int hidraw_open(struct inode *inode, struct file *file)
{
unsigned int minor = iminor(inode);
struct hidraw *dev;
struct hidraw_list *list;
int err = 0;
if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
err = -ENOMEM;
goto out;
}
mutex_lock(&minors_lock);
if (!hidraw_table[minor]) {
err = -ENODEV;
goto out_unlock;
}
list->hidraw = hidraw_table[minor];
mutex_init(&list->read_mutex);
list_add_tail(&list->node, &hidraw_table[minor]->list);
file->private_data = list;
dev = hidraw_table[minor];
if (!dev->open++) {
err = hid_hw_power(dev->hid, PM_HINT_FULLON);
if (err < 0) {
dev->open--;
goto out_unlock;
}
err = hid_hw_open(dev->hid);
if (err < 0) {
hid_hw_power(dev->hid, PM_HINT_NORMAL);
dev->open--;
}
}
out_unlock:
mutex_unlock(&minors_lock);
out:
if (err < 0)
kfree(list);
return err;
}
static int hidraw_release(struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
struct hidraw *dev;
struct hidraw_list *list = file->private_data;
int ret;
mutex_lock(&minors_lock);
if (!hidraw_table[minor]) {
ret = -ENODEV;
goto unlock;
}
list_del(&list->node);
dev = hidraw_table[minor];
if (!--dev->open) {
if (list->hidraw->exist) {
hid_hw_power(dev->hid, PM_HINT_NORMAL);
hid_hw_close(dev->hid);
} else {
kfree(list->hidraw);
}
}
kfree(list);
ret = 0;
unlock:
mutex_unlock(&minors_lock);
return ret;
}
static long hidraw_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
unsigned int minor = iminor(inode);
long ret = 0;
struct hidraw *dev;
void __user *user_arg = (void __user*) arg;
mutex_lock(&minors_lock);
dev = hidraw_table[minor];
if (!dev) {
ret = -ENODEV;
goto out;
}
switch (cmd) {
case HIDIOCGRDESCSIZE:
if (put_user(dev->hid->rsize, (int __user *)arg))
ret = -EFAULT;
break;
case HIDIOCGRDESC:
{
__u32 len;
if (get_user(len, (int __user *)arg))
ret = -EFAULT;
else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
ret = -EINVAL;
else if (copy_to_user(user_arg + offsetof(
struct hidraw_report_descriptor,
value[0]),
dev->hid->rdesc,
min(dev->hid->rsize, len)))
ret = -EFAULT;
break;
}
case HIDIOCGRAWINFO:
{
struct hidraw_devinfo dinfo;
dinfo.bustype = dev->hid->bus;
dinfo.vendor = dev->hid->vendor;
dinfo.product = dev->hid->product;
if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
ret = -EFAULT;
break;
}
default:
{
struct hid_device *hid = dev->hid;
if (_IOC_TYPE(cmd) != 'H') {
ret = -EINVAL;
break;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
int len = _IOC_SIZE(cmd);
ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
break;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
int len = _IOC_SIZE(cmd);
ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
break;
}
/* Begin Read-only ioctls. */
if (_IOC_DIR(cmd) != _IOC_READ) {
ret = -EINVAL;
break;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
int len = strlen(hid->name) + 1;
if (len > _IOC_SIZE(cmd))
len = _IOC_SIZE(cmd);
ret = copy_to_user(user_arg, hid->name, len) ?
-EFAULT : len;
break;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
int len = strlen(hid->phys) + 1;
if (len > _IOC_SIZE(cmd))
len = _IOC_SIZE(cmd);
ret = copy_to_user(user_arg, hid->phys, len) ?
-EFAULT : len;
break;
}
}
ret = -ENOTTY;
}
out:
mutex_unlock(&minors_lock);
return ret;
}
static const struct file_operations hidraw_ops = {
.owner = THIS_MODULE,
.read = hidraw_read,
.write = hidraw_write,
.poll = hidraw_poll,
.open = hidraw_open,
.release = hidraw_release,
.unlocked_ioctl = hidraw_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = hidraw_ioctl,
#endif
.llseek = noop_llseek,
};
void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
{
struct hidraw *dev = hid->hidraw;
struct hidraw_list *list;
list_for_each_entry(list, &dev->list, node) {
list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
list->buffer[list->head].len = len;
list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
}
wake_up_interruptible(&dev->wait);
}
EXPORT_SYMBOL_GPL(hidraw_report_event);
int hidraw_connect(struct hid_device *hid)
{
int minor, result;
struct hidraw *dev;
/* we accept any HID device, no matter the applications */
dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
if (!dev)
return -ENOMEM;
result = -EINVAL;
mutex_lock(&minors_lock);
for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
if (hidraw_table[minor])
continue;
hidraw_table[minor] = dev;
result = 0;
break;
}
if (result) {
mutex_unlock(&minors_lock);
kfree(dev);
goto out;
}
dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
NULL, "%s%d", "hidraw", minor);
if (IS_ERR(dev->dev)) {
hidraw_table[minor] = NULL;
mutex_unlock(&minors_lock);
result = PTR_ERR(dev->dev);
kfree(dev);
goto out;
}
mutex_unlock(&minors_lock);
init_waitqueue_head(&dev->wait);
INIT_LIST_HEAD(&dev->list);
dev->hid = hid;
dev->minor = minor;
dev->exist = 1;
hid->hidraw = dev;
out:
return result;
}
EXPORT_SYMBOL_GPL(hidraw_connect);
void hidraw_disconnect(struct hid_device *hid)
{
struct hidraw *hidraw = hid->hidraw;
mutex_lock(&minors_lock);
hidraw->exist = 0;
device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
hidraw_table[hidraw->minor] = NULL;
if (hidraw->open) {
hid_hw_close(hid);
wake_up_interruptible(&hidraw->wait);
} else {
kfree(hidraw);
}
mutex_unlock(&minors_lock);
}
EXPORT_SYMBOL_GPL(hidraw_disconnect);
int __init hidraw_init(void)
{
int result;
dev_t dev_id;
result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
HIDRAW_MAX_DEVICES, "hidraw");
hidraw_major = MAJOR(dev_id);
if (result < 0) {
pr_warn("can't get major number\n");
result = 0;
goto out;
}
hidraw_class = class_create(THIS_MODULE, "hidraw");
if (IS_ERR(hidraw_class)) {
result = PTR_ERR(hidraw_class);
unregister_chrdev(hidraw_major, "hidraw");
goto out;
}
cdev_init(&hidraw_cdev, &hidraw_ops);
cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
out:
return result;
}
void hidraw_exit(void)
{
dev_t dev_id = MKDEV(hidraw_major, 0);
cdev_del(&hidraw_cdev);
class_destroy(hidraw_class);
unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
}