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->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
102 mutex_unlock(&list->read_mutex);
106 /* The first byte is expected to be a report number.
107 * This function is to be called with the minors_lock mutex held */
108 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
110 unsigned int minor = iminor(file->f_path.dentry->d_inode);
111 struct hid_device *dev;
115 if (!hidraw_table[minor]) {
120 dev = hidraw_table[minor]->hid;
122 if (!dev->hid_output_raw_report) {
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 ret = dev->hid_output_raw_report(dev, buf, count, report_type);
159 /* the first byte is expected to be a report number */
160 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
163 mutex_lock(&minors_lock);
164 ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
165 mutex_unlock(&minors_lock);
170 /* This function performs a Get_Report transfer over the control endpoint
171 * per section 7.2.1 of the HID specification, version 1.1. The first byte
172 * of buffer is the report number to request, or 0x0 if the defice does not
173 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
174 * or HID_INPUT_REPORT. This function is to be called with the minors_lock
176 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
178 unsigned int minor = iminor(file->f_path.dentry->d_inode);
179 struct hid_device *dev;
182 unsigned char report_number;
184 dev = hidraw_table[minor]->hid;
186 if (!dev->hid_get_raw_report) {
191 if (count > HID_MAX_BUFFER_SIZE) {
192 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
193 task_pid_nr(current));
199 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
200 task_pid_nr(current));
205 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
211 /* Read the first byte from the user. This is the report number,
212 * which is passed to dev->hid_get_raw_report(). */
213 if (copy_from_user(&report_number, buffer, 1)) {
218 ret = dev->hid_get_raw_report(dev, report_number, buf, count, report_type);
223 len = (ret < count) ? ret : count;
225 if (copy_to_user(buffer, buf, len)) {
238 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
240 struct hidraw_list *list = file->private_data;
242 poll_wait(file, &list->hidraw->wait, wait);
243 if (list->head != list->tail)
244 return POLLIN | POLLRDNORM;
245 if (!list->hidraw->exist)
246 return POLLERR | POLLHUP;
250 static int hidraw_open(struct inode *inode, struct file *file)
252 unsigned int minor = iminor(inode);
254 struct hidraw_list *list;
257 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
262 mutex_lock(&minors_lock);
263 if (!hidraw_table[minor]) {
268 list->hidraw = hidraw_table[minor];
269 mutex_init(&list->read_mutex);
270 list_add_tail(&list->node, &hidraw_table[minor]->list);
271 file->private_data = list;
273 dev = hidraw_table[minor];
275 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
281 err = hid_hw_open(dev->hid);
283 hid_hw_power(dev->hid, PM_HINT_NORMAL);
289 mutex_unlock(&minors_lock);
297 static int hidraw_release(struct inode * inode, struct file * file)
299 unsigned int minor = iminor(inode);
301 struct hidraw_list *list = file->private_data;
304 mutex_lock(&minors_lock);
305 if (!hidraw_table[minor]) {
310 list_del(&list->node);
311 dev = hidraw_table[minor];
313 if (list->hidraw->exist) {
314 hid_hw_power(dev->hid, PM_HINT_NORMAL);
315 hid_hw_close(dev->hid);
323 mutex_unlock(&minors_lock);
328 static long hidraw_ioctl(struct file *file, unsigned int cmd,
331 struct inode *inode = file->f_path.dentry->d_inode;
332 unsigned int minor = iminor(inode);
335 void __user *user_arg = (void __user*) arg;
337 mutex_lock(&minors_lock);
338 dev = hidraw_table[minor];
345 case HIDIOCGRDESCSIZE:
346 if (put_user(dev->hid->rsize, (int __user *)arg))
354 if (get_user(len, (int __user *)arg))
356 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
358 else if (copy_to_user(user_arg + offsetof(
359 struct hidraw_report_descriptor,
362 min(dev->hid->rsize, len)))
368 struct hidraw_devinfo dinfo;
370 dinfo.bustype = dev->hid->bus;
371 dinfo.vendor = dev->hid->vendor;
372 dinfo.product = dev->hid->product;
373 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
379 struct hid_device *hid = dev->hid;
380 if (_IOC_TYPE(cmd) != 'H') {
385 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
386 int len = _IOC_SIZE(cmd);
387 ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
390 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
391 int len = _IOC_SIZE(cmd);
392 ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
396 /* Begin Read-only ioctls. */
397 if (_IOC_DIR(cmd) != _IOC_READ) {
402 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
403 int len = strlen(hid->name) + 1;
404 if (len > _IOC_SIZE(cmd))
405 len = _IOC_SIZE(cmd);
406 ret = copy_to_user(user_arg, hid->name, len) ?
411 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
412 int len = strlen(hid->phys) + 1;
413 if (len > _IOC_SIZE(cmd))
414 len = _IOC_SIZE(cmd);
415 ret = copy_to_user(user_arg, hid->phys, len) ?
424 mutex_unlock(&minors_lock);
428 static const struct file_operations hidraw_ops = {
429 .owner = THIS_MODULE,
431 .write = hidraw_write,
434 .release = hidraw_release,
435 .unlocked_ioctl = hidraw_ioctl,
437 .compat_ioctl = hidraw_ioctl,
439 .llseek = noop_llseek,
442 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
444 struct hidraw *dev = hid->hidraw;
445 struct hidraw_list *list;
448 list_for_each_entry(list, &dev->list, node) {
449 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
453 list->buffer[list->head].len = len;
454 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
455 kill_fasync(&list->fasync, SIGIO, POLL_IN);
458 wake_up_interruptible(&dev->wait);
461 EXPORT_SYMBOL_GPL(hidraw_report_event);
463 int hidraw_connect(struct hid_device *hid)
468 /* we accept any HID device, no matter the applications */
470 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
476 mutex_lock(&minors_lock);
478 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
479 if (hidraw_table[minor])
481 hidraw_table[minor] = dev;
487 mutex_unlock(&minors_lock);
492 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
493 NULL, "%s%d", "hidraw", minor);
495 if (IS_ERR(dev->dev)) {
496 hidraw_table[minor] = NULL;
497 mutex_unlock(&minors_lock);
498 result = PTR_ERR(dev->dev);
503 mutex_unlock(&minors_lock);
504 init_waitqueue_head(&dev->wait);
505 INIT_LIST_HEAD(&dev->list);
517 EXPORT_SYMBOL_GPL(hidraw_connect);
519 void hidraw_disconnect(struct hid_device *hid)
521 struct hidraw *hidraw = hid->hidraw;
523 mutex_lock(&minors_lock);
526 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
528 hidraw_table[hidraw->minor] = NULL;
532 wake_up_interruptible(&hidraw->wait);
536 mutex_unlock(&minors_lock);
538 EXPORT_SYMBOL_GPL(hidraw_disconnect);
540 int __init hidraw_init(void)
545 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
546 HIDRAW_MAX_DEVICES, "hidraw");
548 hidraw_major = MAJOR(dev_id);
551 pr_warn("can't get major number\n");
556 hidraw_class = class_create(THIS_MODULE, "hidraw");
557 if (IS_ERR(hidraw_class)) {
558 result = PTR_ERR(hidraw_class);
559 unregister_chrdev(hidraw_major, "hidraw");
563 cdev_init(&hidraw_cdev, &hidraw_ops);
564 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
569 void hidraw_exit(void)
571 dev_t dev_id = MKDEV(hidraw_major, 0);
573 cdev_del(&hidraw_cdev);
574 class_destroy(hidraw_class);
575 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);