Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
[linux-2.6.git] / drivers / hid / hidraw.c
1 /*
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/slab.h>
32 #include <linux/hid.h>
33 #include <linux/mutex.h>
34 #include <linux/sched.h>
35 #include <linux/smp_lock.h>
36
37 #include <linux/hidraw.h>
38
39 static int hidraw_major;
40 static struct cdev hidraw_cdev;
41 static struct class *hidraw_class;
42 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
43 static DEFINE_MUTEX(minors_lock);
44
45 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
46 {
47         struct hidraw_list *list = file->private_data;
48         int ret = 0, len;
49         DECLARE_WAITQUEUE(wait, current);
50
51         mutex_lock(&list->read_mutex);
52
53         while (ret == 0) {
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                 len = list->buffer[list->tail].len > count ?
87                         count : list->buffer[list->tail].len;
88
89                 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
90                         ret = -EFAULT;
91                         goto out;
92                 }
93                 ret += len;
94
95                 kfree(list->buffer[list->tail].value);
96                 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
97         }
98 out:
99         mutex_unlock(&list->read_mutex);
100         return ret;
101 }
102
103 /* the first byte is expected to be a report number */
104 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
105 {
106         unsigned int minor = iminor(file->f_path.dentry->d_inode);
107         struct hid_device *dev;
108         __u8 *buf;
109         int ret = 0;
110
111         mutex_lock(&minors_lock);
112
113         if (!hidraw_table[minor]) {
114                 ret = -ENODEV;
115                 goto out;
116         }
117
118         dev = hidraw_table[minor]->hid;
119
120         if (!dev->hid_output_raw_report) {
121                 ret = -ENODEV;
122                 goto out;
123         }
124
125         if (count > HID_MAX_BUFFER_SIZE) {
126                 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
127                                 task_pid_nr(current));
128                 ret = -EINVAL;
129                 goto out;
130         }
131
132         if (count < 2) {
133                 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
134                                 task_pid_nr(current));
135                 ret = -EINVAL;
136                 goto out;
137         }
138
139         buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
140         if (!buf) {
141                 ret = -ENOMEM;
142                 goto out;
143         }
144
145         if (copy_from_user(buf, buffer, count)) {
146                 ret = -EFAULT;
147                 goto out_free;
148         }
149
150         ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT);
151 out_free:
152         kfree(buf);
153 out:
154         mutex_unlock(&minors_lock);
155         return ret;
156 }
157
158 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
159 {
160         struct hidraw_list *list = file->private_data;
161
162         poll_wait(file, &list->hidraw->wait, wait);
163         if (list->head != list->tail)
164                 return POLLIN | POLLRDNORM;
165         if (!list->hidraw->exist)
166                 return POLLERR | POLLHUP;
167         return 0;
168 }
169
170 static int hidraw_open(struct inode *inode, struct file *file)
171 {
172         unsigned int minor = iminor(inode);
173         struct hidraw *dev;
174         struct hidraw_list *list;
175         int err = 0;
176
177         if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
178                 err = -ENOMEM;
179                 goto out;
180         }
181
182         mutex_lock(&minors_lock);
183         if (!hidraw_table[minor]) {
184                 kfree(list);
185                 err = -ENODEV;
186                 goto out_unlock;
187         }
188
189         list->hidraw = hidraw_table[minor];
190         mutex_init(&list->read_mutex);
191         list_add_tail(&list->node, &hidraw_table[minor]->list);
192         file->private_data = list;
193
194         dev = hidraw_table[minor];
195         if (!dev->open++) {
196                 if (dev->hid->ll_driver->power) {
197                         err = dev->hid->ll_driver->power(dev->hid, PM_HINT_FULLON);
198                         if (err < 0)
199                                 goto out_unlock;
200                 }
201                 err = dev->hid->ll_driver->open(dev->hid);
202                 if (err < 0) {
203                         if (dev->hid->ll_driver->power)
204                                 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL);
205                         dev->open--;
206                 }
207         }
208
209 out_unlock:
210         mutex_unlock(&minors_lock);
211 out:
212         return err;
213
214 }
215
216 static int hidraw_release(struct inode * inode, struct file * file)
217 {
218         unsigned int minor = iminor(inode);
219         struct hidraw *dev;
220         struct hidraw_list *list = file->private_data;
221
222         if (!hidraw_table[minor])
223                 return -ENODEV;
224
225         list_del(&list->node);
226         dev = hidraw_table[minor];
227         if (!--dev->open) {
228                 if (list->hidraw->exist) {
229                         if (dev->hid->ll_driver->power)
230                                 dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL);
231                         dev->hid->ll_driver->close(dev->hid);
232                 } else {
233                         kfree(list->hidraw);
234                 }
235         }
236
237         kfree(list);
238
239         return 0;
240 }
241
242 static long hidraw_ioctl(struct file *file, unsigned int cmd,
243                                                         unsigned long arg)
244 {
245         struct inode *inode = file->f_path.dentry->d_inode;
246         unsigned int minor = iminor(inode);
247         long ret = 0;
248         struct hidraw *dev;
249         void __user *user_arg = (void __user*) arg;
250
251         mutex_lock(&minors_lock);
252         dev = hidraw_table[minor];
253         if (!dev) {
254                 ret = -ENODEV;
255                 goto out;
256         }
257
258         switch (cmd) {
259                 case HIDIOCGRDESCSIZE:
260                         if (put_user(dev->hid->rsize, (int __user *)arg))
261                                 ret = -EFAULT;
262                         break;
263
264                 case HIDIOCGRDESC:
265                         {
266                                 __u32 len;
267
268                                 if (get_user(len, (int __user *)arg))
269                                         ret = -EFAULT;
270                                 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
271                                         ret = -EINVAL;
272                                 else if (copy_to_user(user_arg + offsetof(
273                                         struct hidraw_report_descriptor,
274                                         value[0]),
275                                         dev->hid->rdesc,
276                                         min(dev->hid->rsize, len)))
277                                         ret = -EFAULT;
278                                 break;
279                         }
280                 case HIDIOCGRAWINFO:
281                         {
282                                 struct hidraw_devinfo dinfo;
283
284                                 dinfo.bustype = dev->hid->bus;
285                                 dinfo.vendor = dev->hid->vendor;
286                                 dinfo.product = dev->hid->product;
287                                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
288                                         ret = -EFAULT;
289                                 break;
290                         }
291                 default:
292                         {
293                                 struct hid_device *hid = dev->hid;
294                                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) {
295                                         ret = -EINVAL;
296                                         break;
297                                 }
298
299                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
300                                         int len;
301                                         if (!hid->name) {
302                                                 ret = 0;
303                                                 break;
304                                         }
305                                         len = strlen(hid->name) + 1;
306                                         if (len > _IOC_SIZE(cmd))
307                                                 len = _IOC_SIZE(cmd);
308                                         ret = copy_to_user(user_arg, hid->name, len) ?
309                                                 -EFAULT : len;
310                                         break;
311                                 }
312
313                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
314                                         int len;
315                                         if (!hid->phys) {
316                                                 ret = 0;
317                                                 break;
318                                         }
319                                         len = strlen(hid->phys) + 1;
320                                         if (len > _IOC_SIZE(cmd))
321                                                 len = _IOC_SIZE(cmd);
322                                         ret = copy_to_user(user_arg, hid->phys, len) ?
323                                                 -EFAULT : len;
324                                         break;
325                                 }
326                 }
327
328                 ret = -ENOTTY;
329         }
330 out:
331         mutex_unlock(&minors_lock);
332         return ret;
333 }
334
335 static const struct file_operations hidraw_ops = {
336         .owner =        THIS_MODULE,
337         .read =         hidraw_read,
338         .write =        hidraw_write,
339         .poll =         hidraw_poll,
340         .open =         hidraw_open,
341         .release =      hidraw_release,
342         .unlocked_ioctl = hidraw_ioctl,
343         .llseek =       noop_llseek,
344 };
345
346 void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
347 {
348         struct hidraw *dev = hid->hidraw;
349         struct hidraw_list *list;
350
351         list_for_each_entry(list, &dev->list, node) {
352                 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
353                 list->buffer[list->head].len = len;
354                 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
355                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
356         }
357
358         wake_up_interruptible(&dev->wait);
359 }
360 EXPORT_SYMBOL_GPL(hidraw_report_event);
361
362 int hidraw_connect(struct hid_device *hid)
363 {
364         int minor, result;
365         struct hidraw *dev;
366
367         /* we accept any HID device, no matter the applications */
368
369         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
370         if (!dev)
371                 return -ENOMEM;
372
373         result = -EINVAL;
374
375         mutex_lock(&minors_lock);
376
377         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
378                 if (hidraw_table[minor])
379                         continue;
380                 hidraw_table[minor] = dev;
381                 result = 0;
382                 break;
383         }
384
385         if (result) {
386                 mutex_unlock(&minors_lock);
387                 kfree(dev);
388                 goto out;
389         }
390
391         dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
392                                  NULL, "%s%d", "hidraw", minor);
393
394         if (IS_ERR(dev->dev)) {
395                 hidraw_table[minor] = NULL;
396                 mutex_unlock(&minors_lock);
397                 result = PTR_ERR(dev->dev);
398                 kfree(dev);
399                 goto out;
400         }
401
402         mutex_unlock(&minors_lock);
403         init_waitqueue_head(&dev->wait);
404         INIT_LIST_HEAD(&dev->list);
405
406         dev->hid = hid;
407         dev->minor = minor;
408
409         dev->exist = 1;
410         hid->hidraw = dev;
411
412 out:
413         return result;
414
415 }
416 EXPORT_SYMBOL_GPL(hidraw_connect);
417
418 void hidraw_disconnect(struct hid_device *hid)
419 {
420         struct hidraw *hidraw = hid->hidraw;
421
422         hidraw->exist = 0;
423
424         mutex_lock(&minors_lock);
425         hidraw_table[hidraw->minor] = NULL;
426         mutex_unlock(&minors_lock);
427
428         device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
429
430         if (hidraw->open) {
431                 hid->ll_driver->close(hid);
432                 wake_up_interruptible(&hidraw->wait);
433         } else {
434                 kfree(hidraw);
435         }
436 }
437 EXPORT_SYMBOL_GPL(hidraw_disconnect);
438
439 int __init hidraw_init(void)
440 {
441         int result;
442         dev_t dev_id;
443
444         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
445                         HIDRAW_MAX_DEVICES, "hidraw");
446
447         hidraw_major = MAJOR(dev_id);
448
449         if (result < 0) {
450                 printk(KERN_WARNING "hidraw: can't get major number\n");
451                 result = 0;
452                 goto out;
453         }
454
455         hidraw_class = class_create(THIS_MODULE, "hidraw");
456         if (IS_ERR(hidraw_class)) {
457                 result = PTR_ERR(hidraw_class);
458                 unregister_chrdev(hidraw_major, "hidraw");
459                 goto out;
460         }
461
462         cdev_init(&hidraw_cdev, &hidraw_ops);
463         cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
464 out:
465         return result;
466 }
467
468 void hidraw_exit(void)
469 {
470         dev_t dev_id = MKDEV(hidraw_major, 0);
471
472         cdev_del(&hidraw_cdev);
473         class_destroy(hidraw_class);
474         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
475
476 }