Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livep...
[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         dev = hidraw_table[minor]->hid;
196
197         if (!dev->ll_driver->raw_request) {
198                 ret = -ENODEV;
199                 goto out;
200         }
201
202         if (count > HID_MAX_BUFFER_SIZE) {
203                 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
204                                 task_pid_nr(current));
205                 ret = -EINVAL;
206                 goto out;
207         }
208
209         if (count < 2) {
210                 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
211                                 task_pid_nr(current));
212                 ret = -EINVAL;
213                 goto out;
214         }
215
216         buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
217         if (!buf) {
218                 ret = -ENOMEM;
219                 goto out;
220         }
221
222         /*
223          * Read the first byte from the user. This is the report number,
224          * which is passed to hid_hw_raw_request().
225          */
226         if (copy_from_user(&report_number, buffer, 1)) {
227                 ret = -EFAULT;
228                 goto out_free;
229         }
230
231         ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
232                                  HID_REQ_GET_REPORT);
233
234         if (ret < 0)
235                 goto out_free;
236
237         len = (ret < count) ? ret : count;
238
239         if (copy_to_user(buffer, buf, len)) {
240                 ret = -EFAULT;
241                 goto out_free;
242         }
243
244         ret = len;
245
246 out_free:
247         kfree(buf);
248 out:
249         return ret;
250 }
251
252 static __poll_t hidraw_poll(struct file *file, poll_table *wait)
253 {
254         struct hidraw_list *list = file->private_data;
255
256         poll_wait(file, &list->hidraw->wait, wait);
257         if (list->head != list->tail)
258                 return EPOLLIN | EPOLLRDNORM;
259         if (!list->hidraw->exist)
260                 return EPOLLERR | EPOLLHUP;
261         return 0;
262 }
263
264 static int hidraw_open(struct inode *inode, struct file *file)
265 {
266         unsigned int minor = iminor(inode);
267         struct hidraw *dev;
268         struct hidraw_list *list;
269         unsigned long flags;
270         int err = 0;
271
272         if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
273                 err = -ENOMEM;
274                 goto out;
275         }
276
277         mutex_lock(&minors_lock);
278         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
279                 err = -ENODEV;
280                 goto out_unlock;
281         }
282
283         dev = hidraw_table[minor];
284         if (!dev->open++) {
285                 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
286                 if (err < 0) {
287                         dev->open--;
288                         goto out_unlock;
289                 }
290
291                 err = hid_hw_open(dev->hid);
292                 if (err < 0) {
293                         hid_hw_power(dev->hid, PM_HINT_NORMAL);
294                         dev->open--;
295                         goto out_unlock;
296                 }
297         }
298
299         list->hidraw = hidraw_table[minor];
300         mutex_init(&list->read_mutex);
301         spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
302         list_add_tail(&list->node, &hidraw_table[minor]->list);
303         spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
304         file->private_data = list;
305 out_unlock:
306         mutex_unlock(&minors_lock);
307 out:
308         if (err < 0)
309                 kfree(list);
310         return err;
311
312 }
313
314 static int hidraw_fasync(int fd, struct file *file, int on)
315 {
316         struct hidraw_list *list = file->private_data;
317
318         return fasync_helper(fd, file, on, &list->fasync);
319 }
320
321 static void drop_ref(struct hidraw *hidraw, int exists_bit)
322 {
323         if (exists_bit) {
324                 hidraw->exist = 0;
325                 if (hidraw->open) {
326                         hid_hw_close(hidraw->hid);
327                         wake_up_interruptible(&hidraw->wait);
328                 }
329                 device_destroy(hidraw_class,
330                                MKDEV(hidraw_major, hidraw->minor));
331         } else {
332                 --hidraw->open;
333         }
334         if (!hidraw->open) {
335                 if (!hidraw->exist) {
336                         hidraw_table[hidraw->minor] = NULL;
337                         kfree(hidraw);
338                 } else {
339                         /* close device for last reader */
340                         hid_hw_close(hidraw->hid);
341                         hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
342                 }
343         }
344 }
345
346 static int hidraw_release(struct inode * inode, struct file * file)
347 {
348         unsigned int minor = iminor(inode);
349         struct hidraw_list *list = file->private_data;
350         unsigned long flags;
351
352         mutex_lock(&minors_lock);
353
354         spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
355         list_del(&list->node);
356         spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
357         kfree(list);
358
359         drop_ref(hidraw_table[minor], 0);
360
361         mutex_unlock(&minors_lock);
362         return 0;
363 }
364
365 static long hidraw_ioctl(struct file *file, unsigned int cmd,
366                                                         unsigned long arg)
367 {
368         struct inode *inode = file_inode(file);
369         unsigned int minor = iminor(inode);
370         long ret = 0;
371         struct hidraw *dev;
372         void __user *user_arg = (void __user*) arg;
373
374         mutex_lock(&minors_lock);
375         dev = hidraw_table[minor];
376         if (!dev) {
377                 ret = -ENODEV;
378                 goto out;
379         }
380
381         switch (cmd) {
382                 case HIDIOCGRDESCSIZE:
383                         if (put_user(dev->hid->rsize, (int __user *)arg))
384                                 ret = -EFAULT;
385                         break;
386
387                 case HIDIOCGRDESC:
388                         {
389                                 __u32 len;
390
391                                 if (get_user(len, (int __user *)arg))
392                                         ret = -EFAULT;
393                                 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
394                                         ret = -EINVAL;
395                                 else if (copy_to_user(user_arg + offsetof(
396                                         struct hidraw_report_descriptor,
397                                         value[0]),
398                                         dev->hid->rdesc,
399                                         min(dev->hid->rsize, len)))
400                                         ret = -EFAULT;
401                                 break;
402                         }
403                 case HIDIOCGRAWINFO:
404                         {
405                                 struct hidraw_devinfo dinfo;
406
407                                 dinfo.bustype = dev->hid->bus;
408                                 dinfo.vendor = dev->hid->vendor;
409                                 dinfo.product = dev->hid->product;
410                                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
411                                         ret = -EFAULT;
412                                 break;
413                         }
414                 default:
415                         {
416                                 struct hid_device *hid = dev->hid;
417                                 if (_IOC_TYPE(cmd) != 'H') {
418                                         ret = -EINVAL;
419                                         break;
420                                 }
421
422                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
423                                         int len = _IOC_SIZE(cmd);
424                                         ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
425                                         break;
426                                 }
427                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
428                                         int len = _IOC_SIZE(cmd);
429                                         ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
430                                         break;
431                                 }
432
433                                 /* Begin Read-only ioctls. */
434                                 if (_IOC_DIR(cmd) != _IOC_READ) {
435                                         ret = -EINVAL;
436                                         break;
437                                 }
438
439                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
440                                         int len = strlen(hid->name) + 1;
441                                         if (len > _IOC_SIZE(cmd))
442                                                 len = _IOC_SIZE(cmd);
443                                         ret = copy_to_user(user_arg, hid->name, len) ?
444                                                 -EFAULT : len;
445                                         break;
446                                 }
447
448                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
449                                         int len = strlen(hid->phys) + 1;
450                                         if (len > _IOC_SIZE(cmd))
451                                                 len = _IOC_SIZE(cmd);
452                                         ret = copy_to_user(user_arg, hid->phys, len) ?
453                                                 -EFAULT : len;
454                                         break;
455                                 }
456                         }
457
458                 ret = -ENOTTY;
459         }
460 out:
461         mutex_unlock(&minors_lock);
462         return ret;
463 }
464
465 static const struct file_operations hidraw_ops = {
466         .owner =        THIS_MODULE,
467         .read =         hidraw_read,
468         .write =        hidraw_write,
469         .poll =         hidraw_poll,
470         .open =         hidraw_open,
471         .release =      hidraw_release,
472         .unlocked_ioctl = hidraw_ioctl,
473         .fasync =       hidraw_fasync,
474 #ifdef CONFIG_COMPAT
475         .compat_ioctl   = hidraw_ioctl,
476 #endif
477         .llseek =       noop_llseek,
478 };
479
480 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
481 {
482         struct hidraw *dev = hid->hidraw;
483         struct hidraw_list *list;
484         int ret = 0;
485         unsigned long flags;
486
487         spin_lock_irqsave(&dev->list_lock, flags);
488         list_for_each_entry(list, &dev->list, node) {
489                 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
490
491                 if (new_head == list->tail)
492                         continue;
493
494                 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
495                         ret = -ENOMEM;
496                         break;
497                 }
498                 list->buffer[list->head].len = len;
499                 list->head = new_head;
500                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
501         }
502         spin_unlock_irqrestore(&dev->list_lock, flags);
503
504         wake_up_interruptible(&dev->wait);
505         return ret;
506 }
507 EXPORT_SYMBOL_GPL(hidraw_report_event);
508
509 int hidraw_connect(struct hid_device *hid)
510 {
511         int minor, result;
512         struct hidraw *dev;
513
514         /* we accept any HID device, all applications */
515
516         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
517         if (!dev)
518                 return -ENOMEM;
519
520         result = -EINVAL;
521
522         mutex_lock(&minors_lock);
523
524         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
525                 if (hidraw_table[minor])
526                         continue;
527                 hidraw_table[minor] = dev;
528                 result = 0;
529                 break;
530         }
531
532         if (result) {
533                 mutex_unlock(&minors_lock);
534                 kfree(dev);
535                 goto out;
536         }
537
538         dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
539                                  NULL, "%s%d", "hidraw", minor);
540
541         if (IS_ERR(dev->dev)) {
542                 hidraw_table[minor] = NULL;
543                 mutex_unlock(&minors_lock);
544                 result = PTR_ERR(dev->dev);
545                 kfree(dev);
546                 goto out;
547         }
548
549         init_waitqueue_head(&dev->wait);
550         spin_lock_init(&dev->list_lock);
551         INIT_LIST_HEAD(&dev->list);
552
553         dev->hid = hid;
554         dev->minor = minor;
555
556         dev->exist = 1;
557         hid->hidraw = dev;
558
559         mutex_unlock(&minors_lock);
560 out:
561         return result;
562
563 }
564 EXPORT_SYMBOL_GPL(hidraw_connect);
565
566 void hidraw_disconnect(struct hid_device *hid)
567 {
568         struct hidraw *hidraw = hid->hidraw;
569
570         mutex_lock(&minors_lock);
571
572         drop_ref(hidraw, 1);
573
574         mutex_unlock(&minors_lock);
575 }
576 EXPORT_SYMBOL_GPL(hidraw_disconnect);
577
578 int __init hidraw_init(void)
579 {
580         int result;
581         dev_t dev_id;
582
583         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
584                         HIDRAW_MAX_DEVICES, "hidraw");
585         if (result < 0) {
586                 pr_warn("can't get major number\n");
587                 goto out;
588         }
589
590         hidraw_major = MAJOR(dev_id);
591
592         hidraw_class = class_create(THIS_MODULE, "hidraw");
593         if (IS_ERR(hidraw_class)) {
594                 result = PTR_ERR(hidraw_class);
595                 goto error_cdev;
596         }
597
598         cdev_init(&hidraw_cdev, &hidraw_ops);
599         result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
600         if (result < 0)
601                 goto error_class;
602
603         printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n");
604 out:
605         return result;
606
607 error_class:
608         class_destroy(hidraw_class);
609 error_cdev:
610         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
611         goto out;
612 }
613
614 void hidraw_exit(void)
615 {
616         dev_t dev_id = MKDEV(hidraw_major, 0);
617
618         cdev_del(&hidraw_cdev);
619         class_destroy(hidraw_class);
620         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
621
622 }