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) 2007-2014 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 (signal_pending(current)) {
64 if (!list->hidraw->exist) {
68 if (file->f_flags & O_NONBLOCK) {
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);
108 * The first byte of the report buffer is expected to be a report number.
110 * This function is to be called with the minors_lock mutex held.
112 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
114 unsigned int minor = iminor(file_inode(file));
115 struct hid_device *dev;
119 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
124 dev = hidraw_table[minor]->hid;
127 if (count > HID_MAX_BUFFER_SIZE) {
128 hid_warn(dev, "pid %d passed too large report\n",
129 task_pid_nr(current));
135 hid_warn(dev, "pid %d passed too short report\n",
136 task_pid_nr(current));
141 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
147 if (copy_from_user(buf, buffer, count)) {
152 if ((report_type == HID_OUTPUT_REPORT) &&
153 !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
154 ret = hid_hw_output_report(dev, buf, count);
156 * compatibility with old implementation of USB-HID and I2C-HID:
157 * if the device does not support receiving output reports,
158 * on an interrupt endpoint, fallback to SET_REPORT HID command.
164 ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
173 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
176 mutex_lock(&minors_lock);
177 ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
178 mutex_unlock(&minors_lock);
184 * This function performs a Get_Report transfer over the control endpoint
185 * per section 7.2.1 of the HID specification, version 1.1. The first byte
186 * of buffer is the report number to request, or 0x0 if the defice does not
187 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
188 * or HID_INPUT_REPORT.
190 * This function is to be called with the minors_lock mutex held.
192 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
194 unsigned int minor = iminor(file_inode(file));
195 struct hid_device *dev;
198 unsigned char report_number;
200 dev = hidraw_table[minor]->hid;
202 if (!dev->ll_driver->raw_request) {
207 if (count > HID_MAX_BUFFER_SIZE) {
208 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
209 task_pid_nr(current));
215 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
216 task_pid_nr(current));
221 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
228 * Read the first byte from the user. This is the report number,
229 * which is passed to hid_hw_raw_request().
231 if (copy_from_user(&report_number, buffer, 1)) {
236 ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
242 len = (ret < count) ? ret : count;
244 if (copy_to_user(buffer, buf, len)) {
257 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
259 struct hidraw_list *list = file->private_data;
261 poll_wait(file, &list->hidraw->wait, wait);
262 if (list->head != list->tail)
263 return POLLIN | POLLRDNORM;
264 if (!list->hidraw->exist)
265 return POLLERR | POLLHUP;
269 static int hidraw_open(struct inode *inode, struct file *file)
271 unsigned int minor = iminor(inode);
273 struct hidraw_list *list;
277 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
282 mutex_lock(&minors_lock);
283 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
288 dev = hidraw_table[minor];
290 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
296 err = hid_hw_open(dev->hid);
298 hid_hw_power(dev->hid, PM_HINT_NORMAL);
304 list->hidraw = hidraw_table[minor];
305 mutex_init(&list->read_mutex);
306 spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
307 list_add_tail(&list->node, &hidraw_table[minor]->list);
308 spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
309 file->private_data = list;
311 mutex_unlock(&minors_lock);
319 static int hidraw_fasync(int fd, struct file *file, int on)
321 struct hidraw_list *list = file->private_data;
323 return fasync_helper(fd, file, on, &list->fasync);
326 static void drop_ref(struct hidraw *hidraw, int exists_bit)
331 hid_hw_close(hidraw->hid);
332 wake_up_interruptible(&hidraw->wait);
338 if (!hidraw->exist) {
339 device_destroy(hidraw_class,
340 MKDEV(hidraw_major, hidraw->minor));
341 hidraw_table[hidraw->minor] = NULL;
344 /* close device for last reader */
345 hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
346 hid_hw_close(hidraw->hid);
351 static int hidraw_release(struct inode * inode, struct file * file)
353 unsigned int minor = iminor(inode);
354 struct hidraw_list *list = file->private_data;
357 mutex_lock(&minors_lock);
359 spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
360 list_del(&list->node);
361 spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
364 drop_ref(hidraw_table[minor], 0);
366 mutex_unlock(&minors_lock);
370 static long hidraw_ioctl(struct file *file, unsigned int cmd,
373 struct inode *inode = file_inode(file);
374 unsigned int minor = iminor(inode);
377 void __user *user_arg = (void __user*) arg;
379 mutex_lock(&minors_lock);
380 dev = hidraw_table[minor];
387 case HIDIOCGRDESCSIZE:
388 if (put_user(dev->hid->rsize, (int __user *)arg))
396 if (get_user(len, (int __user *)arg))
398 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
400 else if (copy_to_user(user_arg + offsetof(
401 struct hidraw_report_descriptor,
404 min(dev->hid->rsize, len)))
410 struct hidraw_devinfo dinfo;
412 dinfo.bustype = dev->hid->bus;
413 dinfo.vendor = dev->hid->vendor;
414 dinfo.product = dev->hid->product;
415 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
421 struct hid_device *hid = dev->hid;
422 if (_IOC_TYPE(cmd) != 'H') {
427 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
428 int len = _IOC_SIZE(cmd);
429 ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
432 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
433 int len = _IOC_SIZE(cmd);
434 ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
438 /* Begin Read-only ioctls. */
439 if (_IOC_DIR(cmd) != _IOC_READ) {
444 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
445 int len = strlen(hid->name) + 1;
446 if (len > _IOC_SIZE(cmd))
447 len = _IOC_SIZE(cmd);
448 ret = copy_to_user(user_arg, hid->name, len) ?
453 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
454 int len = strlen(hid->phys) + 1;
455 if (len > _IOC_SIZE(cmd))
456 len = _IOC_SIZE(cmd);
457 ret = copy_to_user(user_arg, hid->phys, len) ?
466 mutex_unlock(&minors_lock);
470 static const struct file_operations hidraw_ops = {
471 .owner = THIS_MODULE,
473 .write = hidraw_write,
476 .release = hidraw_release,
477 .unlocked_ioctl = hidraw_ioctl,
478 .fasync = hidraw_fasync,
480 .compat_ioctl = hidraw_ioctl,
482 .llseek = noop_llseek,
485 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
487 struct hidraw *dev = hid->hidraw;
488 struct hidraw_list *list;
492 spin_lock_irqsave(&dev->list_lock, flags);
493 list_for_each_entry(list, &dev->list, node) {
494 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
496 if (new_head == list->tail)
499 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
503 list->buffer[list->head].len = len;
504 list->head = new_head;
505 kill_fasync(&list->fasync, SIGIO, POLL_IN);
507 spin_unlock_irqrestore(&dev->list_lock, flags);
509 wake_up_interruptible(&dev->wait);
512 EXPORT_SYMBOL_GPL(hidraw_report_event);
514 int hidraw_connect(struct hid_device *hid)
519 /* we accept any HID device, all applications */
521 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
527 mutex_lock(&minors_lock);
529 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
530 if (hidraw_table[minor])
532 hidraw_table[minor] = dev;
538 mutex_unlock(&minors_lock);
543 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
544 NULL, "%s%d", "hidraw", minor);
546 if (IS_ERR(dev->dev)) {
547 hidraw_table[minor] = NULL;
548 mutex_unlock(&minors_lock);
549 result = PTR_ERR(dev->dev);
554 init_waitqueue_head(&dev->wait);
555 spin_lock_init(&dev->list_lock);
556 INIT_LIST_HEAD(&dev->list);
564 mutex_unlock(&minors_lock);
569 EXPORT_SYMBOL_GPL(hidraw_connect);
571 void hidraw_disconnect(struct hid_device *hid)
573 struct hidraw *hidraw = hid->hidraw;
575 mutex_lock(&minors_lock);
579 mutex_unlock(&minors_lock);
581 EXPORT_SYMBOL_GPL(hidraw_disconnect);
583 int __init hidraw_init(void)
588 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
589 HIDRAW_MAX_DEVICES, "hidraw");
591 hidraw_major = MAJOR(dev_id);
594 pr_warn("can't get major number\n");
598 hidraw_class = class_create(THIS_MODULE, "hidraw");
599 if (IS_ERR(hidraw_class)) {
600 result = PTR_ERR(hidraw_class);
604 cdev_init(&hidraw_cdev, &hidraw_ops);
605 result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
609 printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n");
614 class_destroy(hidraw_class);
616 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
620 void hidraw_exit(void)
622 dev_t dev_id = MKDEV(hidraw_major, 0);
624 cdev_del(&hidraw_cdev);
625 class_destroy(hidraw_class);
626 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);