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.
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/module.h>
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/cdev.h>
30 #include <linux/poll.h>
31 #include <linux/device.h>
32 #include <linux/major.h>
33 #include <linux/slab.h>
34 #include <linux/hid.h>
35 #include <linux/mutex.h>
36 #include <linux/sched.h>
38 #include <linux/hidraw.h>
40 static int hidraw_major;
41 static struct cdev hidraw_cdev;
42 static struct class *hidraw_class;
43 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
44 static DEFINE_MUTEX(minors_lock);
46 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
48 struct hidraw_list *list = file->private_data;
50 DECLARE_WAITQUEUE(wait, current);
52 mutex_lock(&list->read_mutex);
55 if (list->head == list->tail) {
56 add_wait_queue(&list->hidraw->wait, &wait);
57 set_current_state(TASK_INTERRUPTIBLE);
59 while (list->head == list->tail) {
60 if (file->f_flags & O_NONBLOCK) {
64 if (signal_pending(current)) {
68 if (!list->hidraw->exist) {
73 /* allow O_NONBLOCK to work well from other threads */
74 mutex_unlock(&list->read_mutex);
76 mutex_lock(&list->read_mutex);
77 set_current_state(TASK_INTERRUPTIBLE);
80 set_current_state(TASK_RUNNING);
81 remove_wait_queue(&list->hidraw->wait, &wait);
87 len = list->buffer[list->tail].len > count ?
88 count : list->buffer[list->tail].len;
90 if (list->buffer[list->tail].value) {
91 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
98 kfree(list->buffer[list->tail].value);
99 list->buffer[list->tail].value = NULL;
100 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
103 mutex_unlock(&list->read_mutex);
107 /* The first byte is expected to be a report number.
108 * This function is to be called with the minors_lock mutex held */
109 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
111 unsigned int minor = iminor(file->f_path.dentry->d_inode);
112 struct hid_device *dev;
116 if (!hidraw_table[minor]) {
121 dev = hidraw_table[minor]->hid;
123 if (!dev->hid_output_raw_report) {
128 if (count > HID_MAX_BUFFER_SIZE) {
129 hid_warn(dev, "pid %d passed too large report\n",
130 task_pid_nr(current));
136 hid_warn(dev, "pid %d passed too short report\n",
137 task_pid_nr(current));
142 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
148 if (copy_from_user(buf, buffer, count)) {
153 ret = dev->hid_output_raw_report(dev, buf, count, report_type);
160 /* the first byte is expected to be a report number */
161 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
164 mutex_lock(&minors_lock);
165 ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
166 mutex_unlock(&minors_lock);
171 /* This function performs a Get_Report transfer over the control endpoint
172 * per section 7.2.1 of the HID specification, version 1.1. The first byte
173 * of buffer is the report number to request, or 0x0 if the defice does not
174 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
175 * or HID_INPUT_REPORT. This function is to be called with the minors_lock
177 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
179 unsigned int minor = iminor(file->f_path.dentry->d_inode);
180 struct hid_device *dev;
183 unsigned char report_number;
185 dev = hidraw_table[minor]->hid;
187 if (!dev->hid_get_raw_report) {
192 if (count > HID_MAX_BUFFER_SIZE) {
193 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
194 task_pid_nr(current));
200 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
201 task_pid_nr(current));
206 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
212 /* Read the first byte from the user. This is the report number,
213 * which is passed to dev->hid_get_raw_report(). */
214 if (copy_from_user(&report_number, buffer, 1)) {
219 ret = dev->hid_get_raw_report(dev, report_number, buf, count, report_type);
224 len = (ret < count) ? ret : count;
226 if (copy_to_user(buffer, buf, len)) {
239 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
241 struct hidraw_list *list = file->private_data;
243 poll_wait(file, &list->hidraw->wait, wait);
244 if (list->head != list->tail)
245 return POLLIN | POLLRDNORM;
246 if (!list->hidraw->exist)
247 return POLLERR | POLLHUP;
251 static int hidraw_open(struct inode *inode, struct file *file)
253 unsigned int minor = iminor(inode);
255 struct hidraw_list *list;
258 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
263 mutex_lock(&minors_lock);
264 if (!hidraw_table[minor]) {
269 list->hidraw = hidraw_table[minor];
270 mutex_init(&list->read_mutex);
271 list_add_tail(&list->node, &hidraw_table[minor]->list);
272 file->private_data = list;
274 dev = hidraw_table[minor];
276 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
282 err = hid_hw_open(dev->hid);
284 hid_hw_power(dev->hid, PM_HINT_NORMAL);
290 mutex_unlock(&minors_lock);
298 static int hidraw_release(struct inode * inode, struct file * file)
300 unsigned int minor = iminor(inode);
302 struct hidraw_list *list = file->private_data;
306 mutex_lock(&minors_lock);
307 if (!hidraw_table[minor]) {
312 list_del(&list->node);
313 dev = hidraw_table[minor];
315 if (list->hidraw->exist) {
316 hid_hw_power(dev->hid, PM_HINT_NORMAL);
317 hid_hw_close(dev->hid);
323 for (i = 0; i < HIDRAW_BUFFER_SIZE; ++i)
324 kfree(list->buffer[i].value);
328 mutex_unlock(&minors_lock);
333 static long hidraw_ioctl(struct file *file, unsigned int cmd,
336 struct inode *inode = file->f_path.dentry->d_inode;
337 unsigned int minor = iminor(inode);
340 void __user *user_arg = (void __user*) arg;
342 mutex_lock(&minors_lock);
343 dev = hidraw_table[minor];
350 case HIDIOCGRDESCSIZE:
351 if (put_user(dev->hid->rsize, (int __user *)arg))
359 if (get_user(len, (int __user *)arg))
361 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
363 else if (copy_to_user(user_arg + offsetof(
364 struct hidraw_report_descriptor,
367 min(dev->hid->rsize, len)))
373 struct hidraw_devinfo dinfo;
375 dinfo.bustype = dev->hid->bus;
376 dinfo.vendor = dev->hid->vendor;
377 dinfo.product = dev->hid->product;
378 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
384 struct hid_device *hid = dev->hid;
385 if (_IOC_TYPE(cmd) != 'H') {
390 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
391 int len = _IOC_SIZE(cmd);
392 ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
395 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
396 int len = _IOC_SIZE(cmd);
397 ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
401 /* Begin Read-only ioctls. */
402 if (_IOC_DIR(cmd) != _IOC_READ) {
407 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
408 int len = strlen(hid->name) + 1;
409 if (len > _IOC_SIZE(cmd))
410 len = _IOC_SIZE(cmd);
411 ret = copy_to_user(user_arg, hid->name, len) ?
416 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
417 int len = strlen(hid->phys) + 1;
418 if (len > _IOC_SIZE(cmd))
419 len = _IOC_SIZE(cmd);
420 ret = copy_to_user(user_arg, hid->phys, len) ?
429 mutex_unlock(&minors_lock);
433 static const struct file_operations hidraw_ops = {
434 .owner = THIS_MODULE,
436 .write = hidraw_write,
439 .release = hidraw_release,
440 .unlocked_ioctl = hidraw_ioctl,
442 .compat_ioctl = hidraw_ioctl,
444 .llseek = noop_llseek,
447 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
449 struct hidraw *dev = hid->hidraw;
450 struct hidraw_list *list;
453 list_for_each_entry(list, &dev->list, node) {
454 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
456 if (new_head == list->tail)
459 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
463 list->buffer[list->head].len = len;
464 list->head = new_head;
465 kill_fasync(&list->fasync, SIGIO, POLL_IN);
468 wake_up_interruptible(&dev->wait);
471 EXPORT_SYMBOL_GPL(hidraw_report_event);
473 int hidraw_connect(struct hid_device *hid)
478 /* we accept any HID device, no matter the applications */
480 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
486 mutex_lock(&minors_lock);
488 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
489 if (hidraw_table[minor])
491 hidraw_table[minor] = dev;
497 mutex_unlock(&minors_lock);
502 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
503 NULL, "%s%d", "hidraw", minor);
505 if (IS_ERR(dev->dev)) {
506 hidraw_table[minor] = NULL;
507 mutex_unlock(&minors_lock);
508 result = PTR_ERR(dev->dev);
513 mutex_unlock(&minors_lock);
514 init_waitqueue_head(&dev->wait);
515 INIT_LIST_HEAD(&dev->list);
527 EXPORT_SYMBOL_GPL(hidraw_connect);
529 void hidraw_disconnect(struct hid_device *hid)
531 struct hidraw *hidraw = hid->hidraw;
533 mutex_lock(&minors_lock);
536 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
538 hidraw_table[hidraw->minor] = NULL;
542 wake_up_interruptible(&hidraw->wait);
546 mutex_unlock(&minors_lock);
548 EXPORT_SYMBOL_GPL(hidraw_disconnect);
550 int __init hidraw_init(void)
555 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
556 HIDRAW_MAX_DEVICES, "hidraw");
558 hidraw_major = MAJOR(dev_id);
561 pr_warn("can't get major number\n");
566 hidraw_class = class_create(THIS_MODULE, "hidraw");
567 if (IS_ERR(hidraw_class)) {
568 result = PTR_ERR(hidraw_class);
569 unregister_chrdev(hidraw_major, "hidraw");
573 cdev_init(&hidraw_cdev, &hidraw_ops);
574 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
579 void hidraw_exit(void)
581 dev_t dev_id = MKDEV(hidraw_major, 0);
583 cdev_del(&hidraw_cdev);
584 class_destroy(hidraw_class);
585 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);