Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[muen/linux.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) 2007-2014 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24 #include <linux/fs.h>
25 #include <linux/module.h>
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/cdev.h>
30 #include <linux/poll.h>
31 #include <linux/device.h>
32 #include <linux/major.h>
33 #include <linux/slab.h>
34 #include <linux/hid.h>
35 #include <linux/mutex.h>
36 #include <linux/sched/signal.h>
37 #include <linux/string.h>
38
39 #include <linux/hidraw.h>
40
41 static int hidraw_major;
42 static struct cdev hidraw_cdev;
43 static struct class *hidraw_class;
44 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
45 static DEFINE_MUTEX(minors_lock);
46
47 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
48 {
49         struct hidraw_list *list = file->private_data;
50         int ret = 0, len;
51         DECLARE_WAITQUEUE(wait, current);
52
53         mutex_lock(&list->read_mutex);
54
55         while (ret == 0) {
56                 if (list->head == list->tail) {
57                         add_wait_queue(&list->hidraw->wait, &wait);
58                         set_current_state(TASK_INTERRUPTIBLE);
59
60                         while (list->head == list->tail) {
61                                 if (signal_pending(current)) {
62                                         ret = -ERESTARTSYS;
63                                         break;
64                                 }
65                                 if (!list->hidraw->exist) {
66                                         ret = -EIO;
67                                         break;
68                                 }
69                                 if (file->f_flags & O_NONBLOCK) {
70                                         ret = -EAGAIN;
71                                         break;
72                                 }
73
74                                 /* allow O_NONBLOCK to work well from other threads */
75                                 mutex_unlock(&list->read_mutex);
76                                 schedule();
77                                 mutex_lock(&list->read_mutex);
78                                 set_current_state(TASK_INTERRUPTIBLE);
79                         }
80
81                         set_current_state(TASK_RUNNING);
82                         remove_wait_queue(&list->hidraw->wait, &wait);
83                 }
84
85                 if (ret)
86                         goto out;
87
88                 len = list->buffer[list->tail].len > count ?
89                         count : list->buffer[list->tail].len;
90
91                 if (list->buffer[list->tail].value) {
92                         if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
93                                 ret = -EFAULT;
94                                 goto out;
95                         }
96                         ret = len;
97                 }
98
99                 kfree(list->buffer[list->tail].value);
100                 list->buffer[list->tail].value = NULL;
101                 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
102         }
103 out:
104         mutex_unlock(&list->read_mutex);
105         return ret;
106 }
107
108 /*
109  * The first byte of the report buffer is expected to be a report number.
110  *
111  * This function is to be called with the minors_lock mutex held.
112  */
113 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
114 {
115         unsigned int minor = iminor(file_inode(file));
116         struct hid_device *dev;
117         __u8 *buf;
118         int ret = 0;
119
120         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
121                 ret = -ENODEV;
122                 goto out;
123         }
124
125         dev = hidraw_table[minor]->hid;
126
127         if (count > HID_MAX_BUFFER_SIZE) {
128                 hid_warn(dev, "pid %d passed too large report\n",
129                          task_pid_nr(current));
130                 ret = -EINVAL;
131                 goto out;
132         }
133
134         if (count < 2) {
135                 hid_warn(dev, "pid %d passed too short report\n",
136                          task_pid_nr(current));
137                 ret = -EINVAL;
138                 goto out;
139         }
140
141         buf = memdup_user(buffer, count);
142         if (IS_ERR(buf)) {
143                 ret = PTR_ERR(buf);
144                 goto out;
145         }
146
147         if ((report_type == HID_OUTPUT_REPORT) &&
148             !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
149                 ret = hid_hw_output_report(dev, buf, count);
150                 /*
151                  * compatibility with old implementation of USB-HID and I2C-HID:
152                  * if the device does not support receiving output reports,
153                  * on an interrupt endpoint, fallback to SET_REPORT HID command.
154                  */
155                 if (ret != -ENOSYS)
156                         goto out_free;
157         }
158
159         ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
160                                 HID_REQ_SET_REPORT);
161
162 out_free:
163         kfree(buf);
164 out:
165         return ret;
166 }
167
168 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
169 {
170         ssize_t ret;
171         mutex_lock(&minors_lock);
172         ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
173         mutex_unlock(&minors_lock);
174         return ret;
175 }
176
177
178 /*
179  * This function performs a Get_Report transfer over the control endpoint
180  * per section 7.2.1 of the HID specification, version 1.1.  The first byte
181  * of buffer is the report number to request, or 0x0 if the defice does not
182  * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
183  * or HID_INPUT_REPORT.
184  *
185  * This function is to be called with the minors_lock mutex held.
186  */
187 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
188 {
189         unsigned int minor = iminor(file_inode(file));
190         struct hid_device *dev;
191         __u8 *buf;
192         int ret = 0, len;
193         unsigned char report_number;
194
195         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
196                 ret = -ENODEV;
197                 goto out;
198         }
199
200         dev = hidraw_table[minor]->hid;
201
202         if (!dev->ll_driver->raw_request) {
203                 ret = -ENODEV;
204                 goto out;
205         }
206
207         if (count > HID_MAX_BUFFER_SIZE) {
208                 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
209                                 task_pid_nr(current));
210                 ret = -EINVAL;
211                 goto out;
212         }
213
214         if (count < 2) {
215                 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
216                                 task_pid_nr(current));
217                 ret = -EINVAL;
218                 goto out;
219         }
220
221         buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
222         if (!buf) {
223                 ret = -ENOMEM;
224                 goto out;
225         }
226
227         /*
228          * Read the first byte from the user. This is the report number,
229          * which is passed to hid_hw_raw_request().
230          */
231         if (copy_from_user(&report_number, buffer, 1)) {
232                 ret = -EFAULT;
233                 goto out_free;
234         }
235
236         ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
237                                  HID_REQ_GET_REPORT);
238
239         if (ret < 0)
240                 goto out_free;
241
242         len = (ret < count) ? ret : count;
243
244         if (copy_to_user(buffer, buf, len)) {
245                 ret = -EFAULT;
246                 goto out_free;
247         }
248
249         ret = len;
250
251 out_free:
252         kfree(buf);
253 out:
254         return ret;
255 }
256
257 static __poll_t hidraw_poll(struct file *file, poll_table *wait)
258 {
259         struct hidraw_list *list = file->private_data;
260
261         poll_wait(file, &list->hidraw->wait, wait);
262         if (list->head != list->tail)
263                 return EPOLLIN | EPOLLRDNORM;
264         if (!list->hidraw->exist)
265                 return EPOLLERR | EPOLLHUP;
266         return 0;
267 }
268
269 static int hidraw_open(struct inode *inode, struct file *file)
270 {
271         unsigned int minor = iminor(inode);
272         struct hidraw *dev;
273         struct hidraw_list *list;
274         unsigned long flags;
275         int err = 0;
276
277         if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
278                 err = -ENOMEM;
279                 goto out;
280         }
281
282         mutex_lock(&minors_lock);
283         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
284                 err = -ENODEV;
285                 goto out_unlock;
286         }
287
288         dev = hidraw_table[minor];
289         if (!dev->open++) {
290                 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
291                 if (err < 0) {
292                         dev->open--;
293                         goto out_unlock;
294                 }
295
296                 err = hid_hw_open(dev->hid);
297                 if (err < 0) {
298                         hid_hw_power(dev->hid, PM_HINT_NORMAL);
299                         dev->open--;
300                         goto out_unlock;
301                 }
302         }
303
304         list->hidraw = hidraw_table[minor];
305         mutex_init(&list->read_mutex);
306         spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
307         list_add_tail(&list->node, &hidraw_table[minor]->list);
308         spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
309         file->private_data = list;
310 out_unlock:
311         mutex_unlock(&minors_lock);
312 out:
313         if (err < 0)
314                 kfree(list);
315         return err;
316
317 }
318
319 static int hidraw_fasync(int fd, struct file *file, int on)
320 {
321         struct hidraw_list *list = file->private_data;
322
323         return fasync_helper(fd, file, on, &list->fasync);
324 }
325
326 static void drop_ref(struct hidraw *hidraw, int exists_bit)
327 {
328         if (exists_bit) {
329                 hidraw->exist = 0;
330                 if (hidraw->open) {
331                         hid_hw_close(hidraw->hid);
332                         wake_up_interruptible(&hidraw->wait);
333                 }
334                 device_destroy(hidraw_class,
335                                MKDEV(hidraw_major, hidraw->minor));
336         } else {
337                 --hidraw->open;
338         }
339         if (!hidraw->open) {
340                 if (!hidraw->exist) {
341                         hidraw_table[hidraw->minor] = NULL;
342                         kfree(hidraw);
343                 } else {
344                         /* close device for last reader */
345                         hid_hw_close(hidraw->hid);
346                         hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
347                 }
348         }
349 }
350
351 static int hidraw_release(struct inode * inode, struct file * file)
352 {
353         unsigned int minor = iminor(inode);
354         struct hidraw_list *list = file->private_data;
355         unsigned long flags;
356
357         mutex_lock(&minors_lock);
358
359         spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
360         list_del(&list->node);
361         spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
362         kfree(list);
363
364         drop_ref(hidraw_table[minor], 0);
365
366         mutex_unlock(&minors_lock);
367         return 0;
368 }
369
370 static long hidraw_ioctl(struct file *file, unsigned int cmd,
371                                                         unsigned long arg)
372 {
373         struct inode *inode = file_inode(file);
374         unsigned int minor = iminor(inode);
375         long ret = 0;
376         struct hidraw *dev;
377         void __user *user_arg = (void __user*) arg;
378
379         mutex_lock(&minors_lock);
380         dev = hidraw_table[minor];
381         if (!dev) {
382                 ret = -ENODEV;
383                 goto out;
384         }
385
386         switch (cmd) {
387                 case HIDIOCGRDESCSIZE:
388                         if (put_user(dev->hid->rsize, (int __user *)arg))
389                                 ret = -EFAULT;
390                         break;
391
392                 case HIDIOCGRDESC:
393                         {
394                                 __u32 len;
395
396                                 if (get_user(len, (int __user *)arg))
397                                         ret = -EFAULT;
398                                 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
399                                         ret = -EINVAL;
400                                 else if (copy_to_user(user_arg + offsetof(
401                                         struct hidraw_report_descriptor,
402                                         value[0]),
403                                         dev->hid->rdesc,
404                                         min(dev->hid->rsize, len)))
405                                         ret = -EFAULT;
406                                 break;
407                         }
408                 case HIDIOCGRAWINFO:
409                         {
410                                 struct hidraw_devinfo dinfo;
411
412                                 dinfo.bustype = dev->hid->bus;
413                                 dinfo.vendor = dev->hid->vendor;
414                                 dinfo.product = dev->hid->product;
415                                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
416                                         ret = -EFAULT;
417                                 break;
418                         }
419                 default:
420                         {
421                                 struct hid_device *hid = dev->hid;
422                                 if (_IOC_TYPE(cmd) != 'H') {
423                                         ret = -EINVAL;
424                                         break;
425                                 }
426
427                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
428                                         int len = _IOC_SIZE(cmd);
429                                         ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
430                                         break;
431                                 }
432                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
433                                         int len = _IOC_SIZE(cmd);
434                                         ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
435                                         break;
436                                 }
437
438                                 /* Begin Read-only ioctls. */
439                                 if (_IOC_DIR(cmd) != _IOC_READ) {
440                                         ret = -EINVAL;
441                                         break;
442                                 }
443
444                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
445                                         int len = strlen(hid->name) + 1;
446                                         if (len > _IOC_SIZE(cmd))
447                                                 len = _IOC_SIZE(cmd);
448                                         ret = copy_to_user(user_arg, hid->name, len) ?
449                                                 -EFAULT : len;
450                                         break;
451                                 }
452
453                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
454                                         int len = strlen(hid->phys) + 1;
455                                         if (len > _IOC_SIZE(cmd))
456                                                 len = _IOC_SIZE(cmd);
457                                         ret = copy_to_user(user_arg, hid->phys, len) ?
458                                                 -EFAULT : len;
459                                         break;
460                                 }
461                         }
462
463                 ret = -ENOTTY;
464         }
465 out:
466         mutex_unlock(&minors_lock);
467         return ret;
468 }
469
470 static const struct file_operations hidraw_ops = {
471         .owner =        THIS_MODULE,
472         .read =         hidraw_read,
473         .write =        hidraw_write,
474         .poll =         hidraw_poll,
475         .open =         hidraw_open,
476         .release =      hidraw_release,
477         .unlocked_ioctl = hidraw_ioctl,
478         .fasync =       hidraw_fasync,
479 #ifdef CONFIG_COMPAT
480         .compat_ioctl   = hidraw_ioctl,
481 #endif
482         .llseek =       noop_llseek,
483 };
484
485 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
486 {
487         struct hidraw *dev = hid->hidraw;
488         struct hidraw_list *list;
489         int ret = 0;
490         unsigned long flags;
491
492         spin_lock_irqsave(&dev->list_lock, flags);
493         list_for_each_entry(list, &dev->list, node) {
494                 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
495
496                 if (new_head == list->tail)
497                         continue;
498
499                 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
500                         ret = -ENOMEM;
501                         break;
502                 }
503                 list->buffer[list->head].len = len;
504                 list->head = new_head;
505                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
506         }
507         spin_unlock_irqrestore(&dev->list_lock, flags);
508
509         wake_up_interruptible(&dev->wait);
510         return ret;
511 }
512 EXPORT_SYMBOL_GPL(hidraw_report_event);
513
514 int hidraw_connect(struct hid_device *hid)
515 {
516         int minor, result;
517         struct hidraw *dev;
518
519         /* we accept any HID device, all applications */
520
521         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
522         if (!dev)
523                 return -ENOMEM;
524
525         result = -EINVAL;
526
527         mutex_lock(&minors_lock);
528
529         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
530                 if (hidraw_table[minor])
531                         continue;
532                 hidraw_table[minor] = dev;
533                 result = 0;
534                 break;
535         }
536
537         if (result) {
538                 mutex_unlock(&minors_lock);
539                 kfree(dev);
540                 goto out;
541         }
542
543         dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
544                                  NULL, "%s%d", "hidraw", minor);
545
546         if (IS_ERR(dev->dev)) {
547                 hidraw_table[minor] = NULL;
548                 mutex_unlock(&minors_lock);
549                 result = PTR_ERR(dev->dev);
550                 kfree(dev);
551                 goto out;
552         }
553
554         init_waitqueue_head(&dev->wait);
555         spin_lock_init(&dev->list_lock);
556         INIT_LIST_HEAD(&dev->list);
557
558         dev->hid = hid;
559         dev->minor = minor;
560
561         dev->exist = 1;
562         hid->hidraw = dev;
563
564         mutex_unlock(&minors_lock);
565 out:
566         return result;
567
568 }
569 EXPORT_SYMBOL_GPL(hidraw_connect);
570
571 void hidraw_disconnect(struct hid_device *hid)
572 {
573         struct hidraw *hidraw = hid->hidraw;
574
575         mutex_lock(&minors_lock);
576
577         drop_ref(hidraw, 1);
578
579         mutex_unlock(&minors_lock);
580 }
581 EXPORT_SYMBOL_GPL(hidraw_disconnect);
582
583 int __init hidraw_init(void)
584 {
585         int result;
586         dev_t dev_id;
587
588         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
589                         HIDRAW_MAX_DEVICES, "hidraw");
590         if (result < 0) {
591                 pr_warn("can't get major number\n");
592                 goto out;
593         }
594
595         hidraw_major = MAJOR(dev_id);
596
597         hidraw_class = class_create(THIS_MODULE, "hidraw");
598         if (IS_ERR(hidraw_class)) {
599                 result = PTR_ERR(hidraw_class);
600                 goto error_cdev;
601         }
602
603         cdev_init(&hidraw_cdev, &hidraw_ops);
604         result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
605         if (result < 0)
606                 goto error_class;
607
608         printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n");
609 out:
610         return result;
611
612 error_class:
613         class_destroy(hidraw_class);
614 error_cdev:
615         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
616         goto out;
617 }
618
619 void hidraw_exit(void)
620 {
621         dev_t dev_id = MKDEV(hidraw_major, 0);
622
623         cdev_del(&hidraw_cdev);
624         class_destroy(hidraw_class);
625         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
626
627 }