Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[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/hid.h>
32 #include <linux/mutex.h>
33 #include <linux/smp_lock.h>
34
35 #include <linux/hidraw.h>
36
37 static int hidraw_major;
38 static struct cdev hidraw_cdev;
39 static struct class *hidraw_class;
40 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
41 static DEFINE_MUTEX(minors_lock);
42
43 static 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         }
99 out:
100         mutex_unlock(&list->read_mutex);
101         return ret;
102 }
103
104 /* the first byte is expected to be a report number */
105 static 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);
108         /* FIXME: What stops hidraw_table going NULL */
109         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
116         if (count > HID_MAX_BUFFER_SIZE) {
117                 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
118                                 task_pid_nr(current));
119                 return -EINVAL;
120         }
121
122         if (count < 2) {
123                 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
124                                 task_pid_nr(current));
125                 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);
138 out:
139         kfree(buf);
140         return ret;
141 }
142
143 static 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
155 static 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
167         lock_kernel();
168         mutex_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++) {
184                 err = dev->hid->ll_driver->open(dev->hid);
185                 if (err < 0)
186                         dev->open--;
187         }
188
189 out_unlock:
190         mutex_unlock(&minors_lock);
191         unlock_kernel();
192 out:
193         return err;
194
195 }
196
197 static 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];
211         if (!dev->open--) {
212                 if (list->hidraw->exist)
213                         dev->hid->ll_driver->close(dev->hid);
214                 else
215                         kfree(list->hidraw);
216         }
217
218         kfree(list);
219
220         return 0;
221 }
222
223 static long hidraw_ioctl(struct file *file, unsigned int cmd,
224                                                         unsigned long arg)
225 {
226         struct inode *inode = file->f_path.dentry->d_inode;
227         unsigned int minor = iminor(inode);
228         long ret = 0;
229         /* FIXME: What stops hidraw_table going NULL */
230         struct hidraw *dev = hidraw_table[minor];
231         void __user *user_arg = (void __user*) arg;
232
233         lock_kernel();
234         switch (cmd) {
235                 case HIDIOCGRDESCSIZE:
236                         if (put_user(dev->hid->rsize, (int __user *)arg))
237                                 ret = -EFAULT;
238                         break;
239
240                 case HIDIOCGRDESC:
241                         {
242                                 __u32 len;
243
244                                 if (get_user(len, (int __user *)arg))
245                                         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;
255                         }
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)))
264                                         ret = -EFAULT;
265                                 break;
266                         }
267                 default:
268                         ret = -ENOTTY;
269         }
270         unlock_kernel();
271         return ret;
272 }
273
274 static const struct file_operations hidraw_ops = {
275         .owner =        THIS_MODULE,
276         .read =         hidraw_read,
277         .write =        hidraw_write,
278         .poll =         hidraw_poll,
279         .open =         hidraw_open,
280         .release =      hidraw_release,
281         .unlocked_ioctl = hidraw_ioctl,
282 };
283
284 void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
285 {
286         struct hidraw *dev = hid->hidraw;
287         struct hidraw_list *list;
288
289         list_for_each_entry(list, &dev->list, node) {
290                 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
291                 list->buffer[list->head].len = len;
292                 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
293                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
294         }
295
296         wake_up_interruptible(&dev->wait);
297 }
298 EXPORT_SYMBOL_GPL(hidraw_report_event);
299
300 int hidraw_connect(struct hid_device *hid)
301 {
302         int minor, result;
303         struct hidraw *dev;
304
305         /* TODO currently we accept any HID device. This should later
306          * probably be fixed to accept only those devices which provide
307          * non-input applications
308          */
309
310         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
311         if (!dev)
312                 return -ENOMEM;
313
314         result = -EINVAL;
315
316         mutex_lock(&minors_lock);
317
318         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
319                 if (hidraw_table[minor])
320                         continue;
321                 hidraw_table[minor] = dev;
322                 result = 0;
323                 break;
324         }
325
326         if (result) {
327                 mutex_unlock(&minors_lock);
328                 kfree(dev);
329                 goto out;
330         }
331
332         dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor),
333                                  NULL, "%s%d", "hidraw", minor);
334
335         if (IS_ERR(dev->dev)) {
336                 hidraw_table[minor] = NULL;
337                 mutex_unlock(&minors_lock);
338                 result = PTR_ERR(dev->dev);
339                 kfree(dev);
340                 goto out;
341         }
342
343         mutex_unlock(&minors_lock);
344         init_waitqueue_head(&dev->wait);
345         INIT_LIST_HEAD(&dev->list);
346
347         dev->hid = hid;
348         dev->minor = minor;
349
350         dev->exist = 1;
351         hid->hidraw = dev;
352
353 out:
354         return result;
355
356 }
357 EXPORT_SYMBOL_GPL(hidraw_connect);
358
359 void hidraw_disconnect(struct hid_device *hid)
360 {
361         struct hidraw *hidraw = hid->hidraw;
362
363         hidraw->exist = 0;
364
365         mutex_lock(&minors_lock);
366         hidraw_table[hidraw->minor] = NULL;
367         mutex_unlock(&minors_lock);
368
369         device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
370
371         if (hidraw->open) {
372                 hid->ll_driver->close(hid);
373                 wake_up_interruptible(&hidraw->wait);
374         } else {
375                 kfree(hidraw);
376         }
377 }
378 EXPORT_SYMBOL_GPL(hidraw_disconnect);
379
380 int __init hidraw_init(void)
381 {
382         int result;
383         dev_t dev_id;
384
385         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
386                         HIDRAW_MAX_DEVICES, "hidraw");
387
388         hidraw_major = MAJOR(dev_id);
389
390         if (result < 0) {
391                 printk(KERN_WARNING "hidraw: can't get major number\n");
392                 result = 0;
393                 goto out;
394         }
395
396         hidraw_class = class_create(THIS_MODULE, "hidraw");
397         if (IS_ERR(hidraw_class)) {
398                 result = PTR_ERR(hidraw_class);
399                 unregister_chrdev(hidraw_major, "hidraw");
400                 goto out;
401         }
402
403         cdev_init(&hidraw_cdev, &hidraw_ops);
404         cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
405 out:
406         return result;
407 }
408
409 void hidraw_exit(void)
410 {
411         dev_t dev_id = MKDEV(hidraw_major, 0);
412
413         cdev_del(&hidraw_cdev);
414         class_destroy(hidraw_class);
415         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
416
417 }