pcmcia: fix kernel-doc comments
[linux-2.6] / 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
34 #include <linux/hidraw.h>
35
36 static int hidraw_major;
37 static struct cdev hidraw_cdev;
38 static struct class *hidraw_class;
39 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
40 static DEFINE_SPINLOCK(minors_lock);
41
42 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
43 {
44         struct hidraw_list *list = file->private_data;
45         int ret = 0, len;
46         char *report;
47         DECLARE_WAITQUEUE(wait, current);
48
49         while (ret == 0) {
50
51                 mutex_lock(&list->read_mutex);
52
53                 if (list->head == list->tail) {
54                         add_wait_queue(&list->hidraw->wait, &wait);
55                         set_current_state(TASK_INTERRUPTIBLE);
56
57                         while (list->head == list->tail) {
58                                 if (file->f_flags & O_NONBLOCK) {
59                                         ret = -EAGAIN;
60                                         break;
61                                 }
62                                 if (signal_pending(current)) {
63                                         ret = -ERESTARTSYS;
64                                         break;
65                                 }
66                                 if (!list->hidraw->exist) {
67                                         ret = -EIO;
68                                         break;
69                                 }
70
71                                 /* allow O_NONBLOCK to work well from other threads */
72                                 mutex_unlock(&list->read_mutex);
73                                 schedule();
74                                 mutex_lock(&list->read_mutex);
75                                 set_current_state(TASK_INTERRUPTIBLE);
76                         }
77
78                         set_current_state(TASK_RUNNING);
79                         remove_wait_queue(&list->hidraw->wait, &wait);
80                 }
81
82                 if (ret)
83                         goto out;
84
85                 report = list->buffer[list->tail].value;
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 = hidraw_table[minor]->hid;
108         __u8 *buf;
109         int ret = 0;
110
111         if (!dev->hid_output_raw_report)
112                 return -ENODEV;
113
114         if (count > HID_MIN_BUFFER_SIZE) {
115                 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
116                                 task_pid_nr(current));
117                 return -EINVAL;
118         }
119
120         if (count < 2) {
121                 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
122                                 task_pid_nr(current));
123                 return -EINVAL;
124         }
125
126         buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
127         if (!buf)
128                 return -ENOMEM;
129
130         if (copy_from_user(buf, buffer, count)) {
131                 ret = -EFAULT;
132                 goto out;
133         }
134
135         ret = dev->hid_output_raw_report(dev, buf, count);
136 out:
137         kfree(buf);
138         return ret;
139 }
140
141 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
142 {
143         struct hidraw_list *list = file->private_data;
144
145         poll_wait(file, &list->hidraw->wait, wait);
146         if (list->head != list->tail)
147                 return POLLIN | POLLRDNORM;
148         if (!list->hidraw->exist)
149                 return POLLERR | POLLHUP;
150         return 0;
151 }
152
153 static int hidraw_open(struct inode *inode, struct file *file)
154 {
155         unsigned int minor = iminor(inode);
156         struct hidraw *dev;
157         struct hidraw_list *list;
158         int err = 0;
159
160         if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
161                 err = -ENOMEM;
162                 goto out;
163         }
164
165         spin_lock(&minors_lock);
166         if (!hidraw_table[minor]) {
167                 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
168                                 minor);
169                 kfree(list);
170                 err = -ENODEV;
171                 goto out_unlock;
172         }
173
174         list->hidraw = hidraw_table[minor];
175         mutex_init(&list->read_mutex);
176         list_add_tail(&list->node, &hidraw_table[minor]->list);
177         file->private_data = list;
178
179         dev = hidraw_table[minor];
180         if (!dev->open++)
181                 dev->hid->hid_open(dev->hid);
182
183 out_unlock:
184         spin_unlock(&minors_lock);
185 out:
186         return err;
187
188 }
189
190 static int hidraw_release(struct inode * inode, struct file * file)
191 {
192         unsigned int minor = iminor(inode);
193         struct hidraw *dev;
194         struct hidraw_list *list = file->private_data;
195
196         if (!hidraw_table[minor]) {
197                 printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
198                                 minor);
199                 return -ENODEV;
200         }
201
202         list_del(&list->node);
203         dev = hidraw_table[minor];
204         if (!dev->open--) {
205                 if (list->hidraw->exist)
206                         dev->hid->hid_close(dev->hid);
207                 else
208                         kfree(list->hidraw);
209         }
210
211         return 0;
212 }
213
214 static int hidraw_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
215 {
216         unsigned int minor = iminor(inode);
217         struct hidraw *dev = hidraw_table[minor];
218         void __user *user_arg = (void __user*) arg;
219
220         switch (cmd) {
221                 case HIDIOCGRDESCSIZE:
222                         if (put_user(dev->hid->rsize, (int __user *)arg))
223                                 return -EFAULT;
224                         return 0;
225
226                 case HIDIOCGRDESC:
227                         {
228                                 __u32 len;
229
230                                 if (get_user(len, (int __user *)arg))
231                                         return -EFAULT;
232
233                                 if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
234                                         return -EINVAL;
235
236                                 if (copy_to_user(user_arg + offsetof(
237                                                                 struct hidraw_report_descriptor,
238                                                                 value[0]),
239                                                         dev->hid->rdesc,
240                                                         min(dev->hid->rsize, len)))
241                                                 return -EFAULT;
242                                 return 0;
243                         }
244                 case HIDIOCGRAWINFO:
245                         {
246                                 struct hidraw_devinfo dinfo;
247
248                                 dinfo.bustype = dev->hid->bus;
249                                 dinfo.vendor = dev->hid->vendor;
250                                 dinfo.product = dev->hid->product;
251                                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
252                                         return -EFAULT;
253
254                                 return 0;
255                         }
256                 default:
257                         printk(KERN_EMERG "hidraw: unsupported ioctl() %x\n",
258                                         cmd);
259         }
260         return -EINVAL;
261 }
262
263 static const struct file_operations hidraw_ops = {
264         .owner =        THIS_MODULE,
265         .read =         hidraw_read,
266         .write =        hidraw_write,
267         .poll =         hidraw_poll,
268         .open =         hidraw_open,
269         .release =      hidraw_release,
270         .ioctl =        hidraw_ioctl,
271 };
272
273 void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
274 {
275         struct hidraw *dev = hid->hidraw;
276         struct hidraw_list *list;
277
278         list_for_each_entry(list, &dev->list, node) {
279                 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
280                 list->buffer[list->head].len = len;
281                 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
282                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
283         }
284
285         wake_up_interruptible(&dev->wait);
286 }
287 EXPORT_SYMBOL_GPL(hidraw_report_event);
288
289 int hidraw_connect(struct hid_device *hid)
290 {
291         int minor, result;
292         struct hidraw *dev;
293
294         /* TODO currently we accept any HID device. This should later
295          * probably be fixed to accept only those devices which provide
296          * non-input applications
297          */
298
299         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
300         if (!dev)
301                 return -ENOMEM;
302
303         result = -EINVAL;
304
305         spin_lock(&minors_lock);
306
307         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
308                 if (hidraw_table[minor])
309                         continue;
310                 hidraw_table[minor] = dev;
311                 result = 0;
312                 break;
313         }
314
315         spin_unlock(&minors_lock);
316
317         if (result) {
318                 kfree(dev);
319                 goto out;
320         }
321
322         dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor),
323                                 "%s%d", "hidraw", minor);
324
325         if (IS_ERR(dev->dev)) {
326                 spin_lock(&minors_lock);
327                 hidraw_table[minor] = NULL;
328                 spin_unlock(&minors_lock);
329                 result = PTR_ERR(dev->dev);
330                 kfree(dev);
331                 goto out;
332         }
333
334         init_waitqueue_head(&dev->wait);
335         INIT_LIST_HEAD(&dev->list);
336
337         dev->hid = hid;
338         dev->minor = minor;
339
340         dev->exist = 1;
341         hid->hidraw = dev;
342
343 out:
344         return result;
345
346 }
347 EXPORT_SYMBOL_GPL(hidraw_connect);
348
349 void hidraw_disconnect(struct hid_device *hid)
350 {
351         struct hidraw *hidraw = hid->hidraw;
352
353         hidraw->exist = 0;
354
355         spin_lock(&minors_lock);
356         hidraw_table[hidraw->minor] = NULL;
357         spin_unlock(&minors_lock);
358
359         device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
360
361         if (hidraw->open) {
362                 hid->hid_close(hid);
363                 wake_up_interruptible(&hidraw->wait);
364         } else {
365                 kfree(hidraw);
366         }
367 }
368 EXPORT_SYMBOL_GPL(hidraw_disconnect);
369
370 int __init hidraw_init(void)
371 {
372         int result;
373         dev_t dev_id;
374
375         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
376                         HIDRAW_MAX_DEVICES, "hidraw");
377
378         hidraw_major = MAJOR(dev_id);
379
380         if (result < 0) {
381                 printk(KERN_WARNING "hidraw: can't get major number\n");
382                 result = 0;
383                 goto out;
384         }
385
386         hidraw_class = class_create(THIS_MODULE, "hidraw");
387         if (IS_ERR(hidraw_class)) {
388                 result = PTR_ERR(hidraw_class);
389                 unregister_chrdev(hidraw_major, "hidraw");
390                 goto out;
391         }
392
393         cdev_init(&hidraw_cdev, &hidraw_ops);
394         cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
395 out:
396         return result;
397 }
398
399 void __exit hidraw_exit(void)
400 {
401         dev_t dev_id = MKDEV(hidraw_major, 0);
402
403         cdev_del(&hidraw_cdev);
404         class_destroy(hidraw_class);
405         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
406
407 }