2 * HID raw devices, giving access to raw HID events.
4 * In comparison to hiddev, this device does not process the
5 * hid events at all (no parsing, no lookups). This lets applications
6 * to work on raw hid events as they want to, and avoids a need to
7 * use a transport-specific userspace libhid/libusb libraries.
9 * Copyright (c) 2007 Jiri Kosina
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms and conditions of the GNU General Public License,
15 * version 2, as published by the Free Software Foundation.
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
23 #include <linux/module.h>
24 #include <linux/errno.h>
25 #include <linux/kernel.h>
26 #include <linux/init.h>
27 #include <linux/cdev.h>
28 #include <linux/poll.h>
29 #include <linux/device.h>
30 #include <linux/major.h>
31 #include <linux/slab.h>
32 #include <linux/hid.h>
33 #include <linux/mutex.h>
34 #include <linux/sched.h>
35 #include <linux/smp_lock.h>
37 #include <linux/hidraw.h>
39 static int hidraw_major;
40 static struct cdev hidraw_cdev;
41 static struct class *hidraw_class;
42 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
43 static DEFINE_MUTEX(minors_lock);
45 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
47 struct hidraw_list *list = file->private_data;
49 DECLARE_WAITQUEUE(wait, current);
51 mutex_lock(&list->read_mutex);
54 if (list->head == list->tail) {
55 add_wait_queue(&list->hidraw->wait, &wait);
56 set_current_state(TASK_INTERRUPTIBLE);
58 while (list->head == list->tail) {
59 if (file->f_flags & O_NONBLOCK) {
63 if (signal_pending(current)) {
67 if (!list->hidraw->exist) {
72 /* allow O_NONBLOCK to work well from other threads */
73 mutex_unlock(&list->read_mutex);
75 mutex_lock(&list->read_mutex);
76 set_current_state(TASK_INTERRUPTIBLE);
79 set_current_state(TASK_RUNNING);
80 remove_wait_queue(&list->hidraw->wait, &wait);
86 len = list->buffer[list->tail].len > count ?
87 count : list->buffer[list->tail].len;
89 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
95 kfree(list->buffer[list->tail].value);
96 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
99 mutex_unlock(&list->read_mutex);
103 /* the first byte is expected to be a report number */
104 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
106 unsigned int minor = iminor(file->f_path.dentry->d_inode);
107 struct hid_device *dev;
111 mutex_lock(&minors_lock);
113 if (!hidraw_table[minor]) {
118 dev = hidraw_table[minor]->hid;
120 if (!dev->hid_output_raw_report) {
125 if (count > HID_MAX_BUFFER_SIZE) {
126 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
127 task_pid_nr(current));
133 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
134 task_pid_nr(current));
139 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
145 if (copy_from_user(buf, buffer, count)) {
150 ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT);
154 mutex_unlock(&minors_lock);
158 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
160 struct hidraw_list *list = file->private_data;
162 poll_wait(file, &list->hidraw->wait, wait);
163 if (list->head != list->tail)
164 return POLLIN | POLLRDNORM;
165 if (!list->hidraw->exist)
166 return POLLERR | POLLHUP;
170 static int hidraw_open(struct inode *inode, struct file *file)
172 unsigned int minor = iminor(inode);
174 struct hidraw_list *list;
177 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
182 mutex_lock(&minors_lock);
183 if (!hidraw_table[minor]) {
189 list->hidraw = hidraw_table[minor];
190 mutex_init(&list->read_mutex);
191 list_add_tail(&list->node, &hidraw_table[minor]->list);
192 file->private_data = list;
194 dev = hidraw_table[minor];
196 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
200 err = hid_hw_open(dev->hid);
202 hid_hw_power(dev->hid, PM_HINT_NORMAL);
208 mutex_unlock(&minors_lock);
214 static int hidraw_release(struct inode * inode, struct file * file)
216 unsigned int minor = iminor(inode);
218 struct hidraw_list *list = file->private_data;
221 mutex_lock(&minors_lock);
222 if (!hidraw_table[minor]) {
227 list_del(&list->node);
228 dev = hidraw_table[minor];
230 if (list->hidraw->exist) {
231 hid_hw_power(dev->hid, PM_HINT_NORMAL);
232 hid_hw_close(dev->hid);
240 mutex_unlock(&minors_lock);
245 static long hidraw_ioctl(struct file *file, unsigned int cmd,
248 struct inode *inode = file->f_path.dentry->d_inode;
249 unsigned int minor = iminor(inode);
252 void __user *user_arg = (void __user*) arg;
254 mutex_lock(&minors_lock);
255 dev = hidraw_table[minor];
262 case HIDIOCGRDESCSIZE:
263 if (put_user(dev->hid->rsize, (int __user *)arg))
271 if (get_user(len, (int __user *)arg))
273 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
275 else if (copy_to_user(user_arg + offsetof(
276 struct hidraw_report_descriptor,
279 min(dev->hid->rsize, len)))
285 struct hidraw_devinfo dinfo;
287 dinfo.bustype = dev->hid->bus;
288 dinfo.vendor = dev->hid->vendor;
289 dinfo.product = dev->hid->product;
290 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
296 struct hid_device *hid = dev->hid;
297 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) {
302 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
308 len = strlen(hid->name) + 1;
309 if (len > _IOC_SIZE(cmd))
310 len = _IOC_SIZE(cmd);
311 ret = copy_to_user(user_arg, hid->name, len) ?
316 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
322 len = strlen(hid->phys) + 1;
323 if (len > _IOC_SIZE(cmd))
324 len = _IOC_SIZE(cmd);
325 ret = copy_to_user(user_arg, hid->phys, len) ?
334 mutex_unlock(&minors_lock);
338 static const struct file_operations hidraw_ops = {
339 .owner = THIS_MODULE,
341 .write = hidraw_write,
344 .release = hidraw_release,
345 .unlocked_ioctl = hidraw_ioctl,
346 .llseek = noop_llseek,
349 void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
351 struct hidraw *dev = hid->hidraw;
352 struct hidraw_list *list;
354 list_for_each_entry(list, &dev->list, node) {
355 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
356 list->buffer[list->head].len = len;
357 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
358 kill_fasync(&list->fasync, SIGIO, POLL_IN);
361 wake_up_interruptible(&dev->wait);
363 EXPORT_SYMBOL_GPL(hidraw_report_event);
365 int hidraw_connect(struct hid_device *hid)
370 /* we accept any HID device, no matter the applications */
372 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
378 mutex_lock(&minors_lock);
380 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
381 if (hidraw_table[minor])
383 hidraw_table[minor] = dev;
389 mutex_unlock(&minors_lock);
394 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
395 NULL, "%s%d", "hidraw", minor);
397 if (IS_ERR(dev->dev)) {
398 hidraw_table[minor] = NULL;
399 mutex_unlock(&minors_lock);
400 result = PTR_ERR(dev->dev);
405 mutex_unlock(&minors_lock);
406 init_waitqueue_head(&dev->wait);
407 INIT_LIST_HEAD(&dev->list);
419 EXPORT_SYMBOL_GPL(hidraw_connect);
421 void hidraw_disconnect(struct hid_device *hid)
423 struct hidraw *hidraw = hid->hidraw;
427 mutex_lock(&minors_lock);
428 hidraw_table[hidraw->minor] = NULL;
429 mutex_unlock(&minors_lock);
431 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
435 wake_up_interruptible(&hidraw->wait);
440 EXPORT_SYMBOL_GPL(hidraw_disconnect);
442 int __init hidraw_init(void)
447 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
448 HIDRAW_MAX_DEVICES, "hidraw");
450 hidraw_major = MAJOR(dev_id);
453 printk(KERN_WARNING "hidraw: can't get major number\n");
458 hidraw_class = class_create(THIS_MODULE, "hidraw");
459 if (IS_ERR(hidraw_class)) {
460 result = PTR_ERR(hidraw_class);
461 unregister_chrdev(hidraw_major, "hidraw");
465 cdev_init(&hidraw_cdev, &hidraw_ops);
466 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
471 void hidraw_exit(void)
473 dev_t dev_id = MKDEV(hidraw_major, 0);
475 cdev_del(&hidraw_cdev);
476 class_destroy(hidraw_class);
477 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);