blob: 497e0d1dd3c374c7f65129a487f11bb4c807364a [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];
41static DEFINE_SPINLOCK(minors_lock);
42
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
Jonathan Corbet702e57d2008-05-15 10:25:44 -0600162 lock_kernel();
Jiri Kosina86166b72007-05-14 09:57:40 +0200163 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
164 err = -ENOMEM;
165 goto out;
166 }
167
168 spin_lock(&minors_lock);
169 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];
183 if (!dev->open++)
Jiri Slabyc500c972008-05-16 11:49:16 +0200184 dev->hid->ll_driver->open(dev->hid);
Jiri Kosina86166b72007-05-14 09:57:40 +0200185
186out_unlock:
187 spin_unlock(&minors_lock);
188out:
Jonathan Corbet702e57d2008-05-15 10:25:44 -0600189 unlock_kernel();
Jiri Kosina86166b72007-05-14 09:57:40 +0200190 return err;
191
192}
193
194static int hidraw_release(struct inode * inode, struct file * file)
195{
196 unsigned int minor = iminor(inode);
197 struct hidraw *dev;
198 struct hidraw_list *list = file->private_data;
199
200 if (!hidraw_table[minor]) {
201 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
202 minor);
203 return -ENODEV;
204 }
205
206 list_del(&list->node);
207 dev = hidraw_table[minor];
208 if (!dev->open--) {
209 if (list->hidraw->exist)
Jiri Slabyc500c972008-05-16 11:49:16 +0200210 dev->hid->ll_driver->close(dev->hid);
Jiri Kosina86166b72007-05-14 09:57:40 +0200211 else
212 kfree(list->hidraw);
213 }
214
Jiri Kosina4db1c622008-06-24 14:45:27 +0200215 kfree(list);
216
Jiri Kosina86166b72007-05-14 09:57:40 +0200217 return 0;
218}
219
Alan Cox979c4072008-05-26 11:25:26 +0200220static long hidraw_ioctl(struct file *file, unsigned int cmd,
221 unsigned long arg)
Jiri Kosina86166b72007-05-14 09:57:40 +0200222{
Alan Cox979c4072008-05-26 11:25:26 +0200223 struct inode *inode = file->f_path.dentry->d_inode;
Jiri Kosina86166b72007-05-14 09:57:40 +0200224 unsigned int minor = iminor(inode);
Alan Cox979c4072008-05-26 11:25:26 +0200225 long ret = 0;
226 /* FIXME: What stops hidraw_table going NULL */
Jiri Kosina86166b72007-05-14 09:57:40 +0200227 struct hidraw *dev = hidraw_table[minor];
228 void __user *user_arg = (void __user*) arg;
229
Alan Cox979c4072008-05-26 11:25:26 +0200230 lock_kernel();
Jiri Kosina86166b72007-05-14 09:57:40 +0200231 switch (cmd) {
232 case HIDIOCGRDESCSIZE:
233 if (put_user(dev->hid->rsize, (int __user *)arg))
Alan Cox979c4072008-05-26 11:25:26 +0200234 ret = -EFAULT;
235 break;
Jiri Kosina86166b72007-05-14 09:57:40 +0200236
237 case HIDIOCGRDESC:
238 {
239 __u32 len;
240
241 if (get_user(len, (int __user *)arg))
Alan Cox979c4072008-05-26 11:25:26 +0200242 ret = -EFAULT;
243 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
244 ret = -EINVAL;
245 else if (copy_to_user(user_arg + offsetof(
246 struct hidraw_report_descriptor,
247 value[0]),
248 dev->hid->rdesc,
249 min(dev->hid->rsize, len)))
250 ret = -EFAULT;
251 break;
Jiri Kosina86166b72007-05-14 09:57:40 +0200252 }
253 case HIDIOCGRAWINFO:
254 {
255 struct hidraw_devinfo dinfo;
256
257 dinfo.bustype = dev->hid->bus;
258 dinfo.vendor = dev->hid->vendor;
259 dinfo.product = dev->hid->product;
260 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
Alan Cox979c4072008-05-26 11:25:26 +0200261 ret = -EFAULT;
262 break;
Jiri Kosina86166b72007-05-14 09:57:40 +0200263 }
264 default:
Alan Cox979c4072008-05-26 11:25:26 +0200265 ret = -ENOTTY;
Jiri Kosina86166b72007-05-14 09:57:40 +0200266 }
Alan Cox979c4072008-05-26 11:25:26 +0200267 return ret;
Jiri Kosina86166b72007-05-14 09:57:40 +0200268}
269
270static const struct file_operations hidraw_ops = {
271 .owner = THIS_MODULE,
272 .read = hidraw_read,
273 .write = hidraw_write,
274 .poll = hidraw_poll,
275 .open = hidraw_open,
276 .release = hidraw_release,
Alan Cox979c4072008-05-26 11:25:26 +0200277 .unlocked_ioctl = hidraw_ioctl,
Jiri Kosina86166b72007-05-14 09:57:40 +0200278};
279
280void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
281{
282 struct hidraw *dev = hid->hidraw;
283 struct hidraw_list *list;
284
285 list_for_each_entry(list, &dev->list, node) {
286 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
287 list->buffer[list->head].len = len;
288 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
289 kill_fasync(&list->fasync, SIGIO, POLL_IN);
290 }
291
292 wake_up_interruptible(&dev->wait);
293}
294EXPORT_SYMBOL_GPL(hidraw_report_event);
295
296int hidraw_connect(struct hid_device *hid)
297{
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200298 int minor, result;
Jiri Kosina86166b72007-05-14 09:57:40 +0200299 struct hidraw *dev;
300
301 /* TODO currently we accept any HID device. This should later
302 * probably be fixed to accept only those devices which provide
303 * non-input applications
304 */
305
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200306 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
307 if (!dev)
308 return -ENOMEM;
309
310 result = -EINVAL;
Jiri Kosina86166b72007-05-14 09:57:40 +0200311
312 spin_lock(&minors_lock);
313
314 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
315 if (hidraw_table[minor])
316 continue;
317 hidraw_table[minor] = dev;
318 result = 0;
319 break;
320 }
321
322 spin_unlock(&minors_lock);
323
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200324 if (result) {
325 kfree(dev);
Jiri Kosina86166b72007-05-14 09:57:40 +0200326 goto out;
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200327 }
Jiri Kosina86166b72007-05-14 09:57:40 +0200328
Greg Kroah-Hartman0fd15a12008-05-21 12:52:33 -0700329 dev->dev = device_create_drvdata(hidraw_class, NULL,
330 MKDEV(hidraw_major, minor), NULL,
331 "%s%d", "hidraw", minor);
Jiri Kosina86166b72007-05-14 09:57:40 +0200332
333 if (IS_ERR(dev->dev)) {
334 spin_lock(&minors_lock);
335 hidraw_table[minor] = NULL;
336 spin_unlock(&minors_lock);
337 result = PTR_ERR(dev->dev);
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200338 kfree(dev);
Jiri Kosina86166b72007-05-14 09:57:40 +0200339 goto out;
340 }
341
342 init_waitqueue_head(&dev->wait);
343 INIT_LIST_HEAD(&dev->list);
344
345 dev->hid = hid;
346 dev->minor = minor;
347
348 dev->exist = 1;
349 hid->hidraw = dev;
350
351out:
352 return result;
353
354}
355EXPORT_SYMBOL_GPL(hidraw_connect);
356
357void hidraw_disconnect(struct hid_device *hid)
358{
359 struct hidraw *hidraw = hid->hidraw;
360
361 hidraw->exist = 0;
362
363 spin_lock(&minors_lock);
364 hidraw_table[hidraw->minor] = NULL;
365 spin_unlock(&minors_lock);
366
367 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
368
369 if (hidraw->open) {
Jiri Slabyc500c972008-05-16 11:49:16 +0200370 hid->ll_driver->close(hid);
Jiri Kosina86166b72007-05-14 09:57:40 +0200371 wake_up_interruptible(&hidraw->wait);
372 } else {
373 kfree(hidraw);
374 }
375}
376EXPORT_SYMBOL_GPL(hidraw_disconnect);
377
378int __init hidraw_init(void)
379{
380 int result;
381 dev_t dev_id;
382
383 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
384 HIDRAW_MAX_DEVICES, "hidraw");
385
386 hidraw_major = MAJOR(dev_id);
387
388 if (result < 0) {
389 printk(KERN_WARNING "hidraw: can't get major number\n");
390 result = 0;
391 goto out;
392 }
393
394 hidraw_class = class_create(THIS_MODULE, "hidraw");
395 if (IS_ERR(hidraw_class)) {
396 result = PTR_ERR(hidraw_class);
397 unregister_chrdev(hidraw_major, "hidraw");
398 goto out;
399 }
400
401 cdev_init(&hidraw_cdev, &hidraw_ops);
402 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
403out:
404 return result;
405}
406
407void __exit hidraw_exit(void)
408{
409 dev_t dev_id = MKDEV(hidraw_major, 0);
410
411 cdev_del(&hidraw_cdev);
412 class_destroy(hidraw_class);
413 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
414
415}