blob: 02b19db5442ebd1d1fce7c0716bb2a071f528e12 [file] [log] [blame]
Jiri Kosina86166b72007-05-14 09:57:40 +02001/*
2 * HID raw devices, giving access to raw HID events.
3 *
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.
8 *
9 * Copyright (c) 2007 Jiri Kosina
10 */
11
12/*
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.
16 *
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.
20 */
21
22#include <linux/fs.h>
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/hid.h>
32#include <linux/mutex.h>
Jonathan Corbet702e57d2008-05-15 10:25:44 -060033#include <linux/smp_lock.h>
Jiri Kosina86166b72007-05-14 09:57:40 +020034
35#include <linux/hidraw.h>
36
37static int hidraw_major;
38static struct cdev hidraw_cdev;
39static struct class *hidraw_class;
40static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
Oliver Neukum7d672cd2008-10-31 00:07:23 +010041static DEFINE_MUTEX(minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +020042
43static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
44{
45 struct hidraw_list *list = file->private_data;
46 int ret = 0, len;
47 char *report;
48 DECLARE_WAITQUEUE(wait, current);
49
50 while (ret == 0) {
51
52 mutex_lock(&list->read_mutex);
53
54 if (list->head == list->tail) {
55 add_wait_queue(&list->hidraw->wait, &wait);
56 set_current_state(TASK_INTERRUPTIBLE);
57
58 while (list->head == list->tail) {
59 if (file->f_flags & O_NONBLOCK) {
60 ret = -EAGAIN;
61 break;
62 }
63 if (signal_pending(current)) {
64 ret = -ERESTARTSYS;
65 break;
66 }
67 if (!list->hidraw->exist) {
68 ret = -EIO;
69 break;
70 }
71
72 /* allow O_NONBLOCK to work well from other threads */
73 mutex_unlock(&list->read_mutex);
74 schedule();
75 mutex_lock(&list->read_mutex);
76 set_current_state(TASK_INTERRUPTIBLE);
77 }
78
79 set_current_state(TASK_RUNNING);
80 remove_wait_queue(&list->hidraw->wait, &wait);
81 }
82
83 if (ret)
84 goto out;
85
86 report = list->buffer[list->tail].value;
87 len = list->buffer[list->tail].len > count ?
88 count : list->buffer[list->tail].len;
89
90 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
91 ret = -EFAULT;
92 goto out;
93 }
94 ret += len;
95
96 kfree(list->buffer[list->tail].value);
97 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
98 }
99out:
100 mutex_unlock(&list->read_mutex);
101 return ret;
102}
103
104/* the first byte is expected to be a report number */
105static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
106{
107 unsigned int minor = iminor(file->f_path.dentry->d_inode);
Alan Cox979c4072008-05-26 11:25:26 +0200108 /* FIXME: What stops hidraw_table going NULL */
Jiri Kosina86166b72007-05-14 09:57:40 +0200109 struct hid_device *dev = hidraw_table[minor]->hid;
110 __u8 *buf;
111 int ret = 0;
112
113 if (!dev->hid_output_raw_report)
114 return -ENODEV;
115
Jiri Kosina2b107d62008-09-17 19:41:58 +0200116 if (count > HID_MAX_BUFFER_SIZE) {
Jiri Kosina86166b72007-05-14 09:57:40 +0200117 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -0700118 task_pid_nr(current));
Jiri Kosina86166b72007-05-14 09:57:40 +0200119 return -EINVAL;
120 }
121
122 if (count < 2) {
123 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -0700124 task_pid_nr(current));
Jiri Kosina86166b72007-05-14 09:57:40 +0200125 return -EINVAL;
126 }
127
128 buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
129 if (!buf)
130 return -ENOMEM;
131
132 if (copy_from_user(buf, buffer, count)) {
133 ret = -EFAULT;
134 goto out;
135 }
136
137 ret = dev->hid_output_raw_report(dev, buf, count);
138out:
139 kfree(buf);
140 return ret;
141}
142
143static unsigned int hidraw_poll(struct file *file, poll_table *wait)
144{
145 struct hidraw_list *list = file->private_data;
146
147 poll_wait(file, &list->hidraw->wait, wait);
148 if (list->head != list->tail)
149 return POLLIN | POLLRDNORM;
150 if (!list->hidraw->exist)
151 return POLLERR | POLLHUP;
152 return 0;
153}
154
155static int hidraw_open(struct inode *inode, struct file *file)
156{
157 unsigned int minor = iminor(inode);
158 struct hidraw *dev;
159 struct hidraw_list *list;
160 int err = 0;
161
162 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
163 err = -ENOMEM;
164 goto out;
165 }
166
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100167 lock_kernel();
168 mutex_lock(&minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +0200169 if (!hidraw_table[minor]) {
170 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
171 minor);
172 kfree(list);
173 err = -ENODEV;
174 goto out_unlock;
175 }
176
177 list->hidraw = hidraw_table[minor];
178 mutex_init(&list->read_mutex);
179 list_add_tail(&list->node, &hidraw_table[minor]->list);
180 file->private_data = list;
181
182 dev = hidraw_table[minor];
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100183 if (!dev->open++) {
184 err = dev->hid->ll_driver->open(dev->hid);
185 if (err < 0)
186 dev->open--;
187 }
Jiri Kosina86166b72007-05-14 09:57:40 +0200188
189out_unlock:
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100190 mutex_unlock(&minors_lock);
Jonathan Corbet702e57d2008-05-15 10:25:44 -0600191 unlock_kernel();
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100192out:
Jiri Kosina86166b72007-05-14 09:57:40 +0200193 return err;
194
195}
196
197static int hidraw_release(struct inode * inode, struct file * file)
198{
199 unsigned int minor = iminor(inode);
200 struct hidraw *dev;
201 struct hidraw_list *list = file->private_data;
202
203 if (!hidraw_table[minor]) {
204 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
205 minor);
206 return -ENODEV;
207 }
208
209 list_del(&list->node);
210 dev = hidraw_table[minor];
Oliver Neukumb8a832b2008-12-15 13:12:08 +0100211 if (!--dev->open) {
Jiri Kosina86166b72007-05-14 09:57:40 +0200212 if (list->hidraw->exist)
Jiri Slabyc500c972008-05-16 11:49:16 +0200213 dev->hid->ll_driver->close(dev->hid);
Jiri Kosina86166b72007-05-14 09:57:40 +0200214 else
215 kfree(list->hidraw);
216 }
217
Jiri Kosina4db1c622008-06-24 14:45:27 +0200218 kfree(list);
219
Jiri Kosina86166b72007-05-14 09:57:40 +0200220 return 0;
221}
222
Alan Cox979c4072008-05-26 11:25:26 +0200223static long hidraw_ioctl(struct file *file, unsigned int cmd,
224 unsigned long arg)
Jiri Kosina86166b72007-05-14 09:57:40 +0200225{
Alan Cox979c4072008-05-26 11:25:26 +0200226 struct inode *inode = file->f_path.dentry->d_inode;
Jiri Kosina86166b72007-05-14 09:57:40 +0200227 unsigned int minor = iminor(inode);
Alan Cox979c4072008-05-26 11:25:26 +0200228 long ret = 0;
229 /* FIXME: What stops hidraw_table going NULL */
Jiri Kosina86166b72007-05-14 09:57:40 +0200230 struct hidraw *dev = hidraw_table[minor];
231 void __user *user_arg = (void __user*) arg;
232
Alan Cox979c4072008-05-26 11:25:26 +0200233 lock_kernel();
Jiri Kosina86166b72007-05-14 09:57:40 +0200234 switch (cmd) {
235 case HIDIOCGRDESCSIZE:
236 if (put_user(dev->hid->rsize, (int __user *)arg))
Alan Cox979c4072008-05-26 11:25:26 +0200237 ret = -EFAULT;
238 break;
Jiri Kosina86166b72007-05-14 09:57:40 +0200239
240 case HIDIOCGRDESC:
241 {
242 __u32 len;
243
244 if (get_user(len, (int __user *)arg))
Alan Cox979c4072008-05-26 11:25:26 +0200245 ret = -EFAULT;
246 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
247 ret = -EINVAL;
248 else if (copy_to_user(user_arg + offsetof(
249 struct hidraw_report_descriptor,
250 value[0]),
251 dev->hid->rdesc,
252 min(dev->hid->rsize, len)))
253 ret = -EFAULT;
254 break;
Jiri Kosina86166b72007-05-14 09:57:40 +0200255 }
256 case HIDIOCGRAWINFO:
257 {
258 struct hidraw_devinfo dinfo;
259
260 dinfo.bustype = dev->hid->bus;
261 dinfo.vendor = dev->hid->vendor;
262 dinfo.product = dev->hid->product;
263 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
Alan Cox979c4072008-05-26 11:25:26 +0200264 ret = -EFAULT;
265 break;
Jiri Kosina86166b72007-05-14 09:57:40 +0200266 }
267 default:
Jiri Kosina9188e792008-11-12 16:14:08 +0100268 {
269 struct hid_device *hid = dev->hid;
Dan Carpenterdfd395af2009-02-03 16:35:17 +0300270 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) {
271 ret = -EINVAL;
272 break;
273 }
Jiri Kosina9188e792008-11-12 16:14:08 +0100274
275 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
276 int len;
277 if (!hid->name)
278 return 0;
279 len = strlen(hid->name) + 1;
280 if (len > _IOC_SIZE(cmd))
281 len = _IOC_SIZE(cmd);
Dan Carpenterdfd395af2009-02-03 16:35:17 +0300282 ret = copy_to_user(user_arg, hid->name, len) ?
Jiri Kosina9188e792008-11-12 16:14:08 +0100283 -EFAULT : len;
Dan Carpenterdfd395af2009-02-03 16:35:17 +0300284 break;
Jiri Kosina9188e792008-11-12 16:14:08 +0100285 }
286
287 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
288 int len;
289 if (!hid->phys)
290 return 0;
291 len = strlen(hid->phys) + 1;
292 if (len > _IOC_SIZE(cmd))
293 len = _IOC_SIZE(cmd);
Dan Carpenterdfd395af2009-02-03 16:35:17 +0300294 ret = copy_to_user(user_arg, hid->phys, len) ?
Jiri Kosina9188e792008-11-12 16:14:08 +0100295 -EFAULT : len;
Dan Carpenterdfd395af2009-02-03 16:35:17 +0300296 break;
Jiri Kosina9188e792008-11-12 16:14:08 +0100297 }
298 }
299
Dan Carpenterdfd395af2009-02-03 16:35:17 +0300300 ret = -ENOTTY;
Jiri Kosina86166b72007-05-14 09:57:40 +0200301 }
Jiri Slaby0f2c5942008-10-23 01:47:30 +0200302 unlock_kernel();
Alan Cox979c4072008-05-26 11:25:26 +0200303 return ret;
Jiri Kosina86166b72007-05-14 09:57:40 +0200304}
305
306static const struct file_operations hidraw_ops = {
307 .owner = THIS_MODULE,
308 .read = hidraw_read,
309 .write = hidraw_write,
310 .poll = hidraw_poll,
311 .open = hidraw_open,
312 .release = hidraw_release,
Alan Cox979c4072008-05-26 11:25:26 +0200313 .unlocked_ioctl = hidraw_ioctl,
Jiri Kosina86166b72007-05-14 09:57:40 +0200314};
315
316void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
317{
318 struct hidraw *dev = hid->hidraw;
319 struct hidraw_list *list;
320
321 list_for_each_entry(list, &dev->list, node) {
322 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
323 list->buffer[list->head].len = len;
324 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
325 kill_fasync(&list->fasync, SIGIO, POLL_IN);
326 }
327
328 wake_up_interruptible(&dev->wait);
329}
330EXPORT_SYMBOL_GPL(hidraw_report_event);
331
332int hidraw_connect(struct hid_device *hid)
333{
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200334 int minor, result;
Jiri Kosina86166b72007-05-14 09:57:40 +0200335 struct hidraw *dev;
336
337 /* TODO currently we accept any HID device. This should later
338 * probably be fixed to accept only those devices which provide
339 * non-input applications
340 */
341
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200342 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
343 if (!dev)
344 return -ENOMEM;
345
346 result = -EINVAL;
Jiri Kosina86166b72007-05-14 09:57:40 +0200347
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100348 mutex_lock(&minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +0200349
350 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
351 if (hidraw_table[minor])
352 continue;
353 hidraw_table[minor] = dev;
354 result = 0;
355 break;
356 }
357
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200358 if (result) {
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100359 mutex_unlock(&minors_lock);
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200360 kfree(dev);
Jiri Kosina86166b72007-05-14 09:57:40 +0200361 goto out;
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200362 }
Jiri Kosina86166b72007-05-14 09:57:40 +0200363
Jiri Kosinaaae6c282008-12-04 16:16:46 +0100364 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700365 NULL, "%s%d", "hidraw", minor);
Jiri Kosina86166b72007-05-14 09:57:40 +0200366
367 if (IS_ERR(dev->dev)) {
Jiri Kosina86166b72007-05-14 09:57:40 +0200368 hidraw_table[minor] = NULL;
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100369 mutex_unlock(&minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +0200370 result = PTR_ERR(dev->dev);
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200371 kfree(dev);
Jiri Kosina86166b72007-05-14 09:57:40 +0200372 goto out;
373 }
374
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100375 mutex_unlock(&minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +0200376 init_waitqueue_head(&dev->wait);
377 INIT_LIST_HEAD(&dev->list);
378
379 dev->hid = hid;
380 dev->minor = minor;
381
382 dev->exist = 1;
383 hid->hidraw = dev;
384
385out:
386 return result;
387
388}
389EXPORT_SYMBOL_GPL(hidraw_connect);
390
391void hidraw_disconnect(struct hid_device *hid)
392{
393 struct hidraw *hidraw = hid->hidraw;
394
395 hidraw->exist = 0;
396
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100397 mutex_lock(&minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +0200398 hidraw_table[hidraw->minor] = NULL;
Oliver Neukum7d672cd2008-10-31 00:07:23 +0100399 mutex_unlock(&minors_lock);
Jiri Kosina86166b72007-05-14 09:57:40 +0200400
401 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
402
403 if (hidraw->open) {
Jiri Slabyc500c972008-05-16 11:49:16 +0200404 hid->ll_driver->close(hid);
Jiri Kosina86166b72007-05-14 09:57:40 +0200405 wake_up_interruptible(&hidraw->wait);
406 } else {
407 kfree(hidraw);
408 }
409}
410EXPORT_SYMBOL_GPL(hidraw_disconnect);
411
412int __init hidraw_init(void)
413{
414 int result;
415 dev_t dev_id;
416
417 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
418 HIDRAW_MAX_DEVICES, "hidraw");
419
420 hidraw_major = MAJOR(dev_id);
421
422 if (result < 0) {
423 printk(KERN_WARNING "hidraw: can't get major number\n");
424 result = 0;
425 goto out;
426 }
427
428 hidraw_class = class_create(THIS_MODULE, "hidraw");
429 if (IS_ERR(hidraw_class)) {
430 result = PTR_ERR(hidraw_class);
431 unregister_chrdev(hidraw_major, "hidraw");
432 goto out;
433 }
434
435 cdev_init(&hidraw_cdev, &hidraw_ops);
436 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
437out:
438 return result;
439}
440
Jiri Slaby140ae3e2008-10-17 18:04:48 +0200441void hidraw_exit(void)
Jiri Kosina86166b72007-05-14 09:57:40 +0200442{
443 dev_t dev_id = MKDEV(hidraw_major, 0);
444
445 cdev_del(&hidraw_cdev);
446 class_destroy(hidraw_class);
447 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
448
449}