17d15bb610d15ac4b544e11af3007cd5b6357fd8
[~shefty/rdma-dev.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 #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.h>
37
38 #include <linux/hidraw.h>
39
40 static int hidraw_major;
41 static struct cdev hidraw_cdev;
42 static struct class *hidraw_class;
43 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
44 static DEFINE_MUTEX(minors_lock);
45 static void drop_ref(struct hidraw *hid, int exists_bit);
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 (file->f_flags & O_NONBLOCK) {
62                                         ret = -EAGAIN;
63                                         break;
64                                 }
65                                 if (signal_pending(current)) {
66                                         ret = -ERESTARTSYS;
67                                         break;
68                                 }
69                                 if (!list->hidraw->exist) {
70                                         ret = -EIO;
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 /* The first byte is expected to be a report number.
109  * This function is to be called with the minors_lock mutex held */
110 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
111 {
112         unsigned int minor = iminor(file->f_path.dentry->d_inode);
113         struct hid_device *dev;
114         __u8 *buf;
115         int ret = 0;
116
117         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
118                 ret = -ENODEV;
119                 goto out;
120         }
121
122         dev = hidraw_table[minor]->hid;
123
124         if (!dev->hid_output_raw_report) {
125                 ret = -ENODEV;
126                 goto out;
127         }
128
129         if (count > HID_MAX_BUFFER_SIZE) {
130                 hid_warn(dev, "pid %d passed too large report\n",
131                          task_pid_nr(current));
132                 ret = -EINVAL;
133                 goto out;
134         }
135
136         if (count < 2) {
137                 hid_warn(dev, "pid %d passed too short report\n",
138                          task_pid_nr(current));
139                 ret = -EINVAL;
140                 goto out;
141         }
142
143         buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
144         if (!buf) {
145                 ret = -ENOMEM;
146                 goto out;
147         }
148
149         if (copy_from_user(buf, buffer, count)) {
150                 ret = -EFAULT;
151                 goto out_free;
152         }
153
154         ret = dev->hid_output_raw_report(dev, buf, count, report_type);
155 out_free:
156         kfree(buf);
157 out:
158         return ret;
159 }
160
161 /* the first byte is expected to be a report number */
162 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
163 {
164         ssize_t ret;
165         mutex_lock(&minors_lock);
166         ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
167         mutex_unlock(&minors_lock);
168         return ret;
169 }
170
171
172 /* This function performs a Get_Report transfer over the control endpoint
173  * per section 7.2.1 of the HID specification, version 1.1.  The first byte
174  * of buffer is the report number to request, or 0x0 if the defice does not
175  * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
176  * or HID_INPUT_REPORT.  This function is to be called with the minors_lock
177  *  mutex held. */
178 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
179 {
180         unsigned int minor = iminor(file->f_path.dentry->d_inode);
181         struct hid_device *dev;
182         __u8 *buf;
183         int ret = 0, len;
184         unsigned char report_number;
185
186         dev = hidraw_table[minor]->hid;
187
188         if (!dev->hid_get_raw_report) {
189                 ret = -ENODEV;
190                 goto out;
191         }
192
193         if (count > HID_MAX_BUFFER_SIZE) {
194                 printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
195                                 task_pid_nr(current));
196                 ret = -EINVAL;
197                 goto out;
198         }
199
200         if (count < 2) {
201                 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
202                                 task_pid_nr(current));
203                 ret = -EINVAL;
204                 goto out;
205         }
206
207         buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
208         if (!buf) {
209                 ret = -ENOMEM;
210                 goto out;
211         }
212
213         /* Read the first byte from the user. This is the report number,
214          * which is passed to dev->hid_get_raw_report(). */
215         if (copy_from_user(&report_number, buffer, 1)) {
216                 ret = -EFAULT;
217                 goto out_free;
218         }
219
220         ret = dev->hid_get_raw_report(dev, report_number, buf, count, report_type);
221
222         if (ret < 0)
223                 goto out_free;
224
225         len = (ret < count) ? ret : count;
226
227         if (copy_to_user(buffer, buf, len)) {
228                 ret = -EFAULT;
229                 goto out_free;
230         }
231
232         ret = len;
233
234 out_free:
235         kfree(buf);
236 out:
237         return ret;
238 }
239
240 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
241 {
242         struct hidraw_list *list = file->private_data;
243
244         poll_wait(file, &list->hidraw->wait, wait);
245         if (list->head != list->tail)
246                 return POLLIN | POLLRDNORM;
247         if (!list->hidraw->exist)
248                 return POLLERR | POLLHUP;
249         return 0;
250 }
251
252 static int hidraw_open(struct inode *inode, struct file *file)
253 {
254         unsigned int minor = iminor(inode);
255         struct hidraw *dev;
256         struct hidraw_list *list;
257         int err = 0;
258
259         if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
260                 err = -ENOMEM;
261                 goto out;
262         }
263
264         mutex_lock(&minors_lock);
265         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
266                 err = -ENODEV;
267                 goto out_unlock;
268         }
269
270         list->hidraw = hidraw_table[minor];
271         mutex_init(&list->read_mutex);
272         list_add_tail(&list->node, &hidraw_table[minor]->list);
273         file->private_data = list;
274
275         dev = hidraw_table[minor];
276         if (!dev->open++) {
277                 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
278                 if (err < 0) {
279                         dev->open--;
280                         goto out_unlock;
281                 }
282
283                 err = hid_hw_open(dev->hid);
284                 if (err < 0) {
285                         hid_hw_power(dev->hid, PM_HINT_NORMAL);
286                         dev->open--;
287                 }
288         }
289
290 out_unlock:
291         mutex_unlock(&minors_lock);
292 out:
293         if (err < 0)
294                 kfree(list);
295         return err;
296
297 }
298
299 static int hidraw_release(struct inode * inode, struct file * file)
300 {
301         unsigned int minor = iminor(inode);
302         struct hidraw_list *list = file->private_data;
303
304         drop_ref(hidraw_table[minor], 0);
305         list_del(&list->node);
306         kfree(list);
307         return 0;
308 }
309
310 static long hidraw_ioctl(struct file *file, unsigned int cmd,
311                                                         unsigned long arg)
312 {
313         struct inode *inode = file->f_path.dentry->d_inode;
314         unsigned int minor = iminor(inode);
315         long ret = 0;
316         struct hidraw *dev;
317         void __user *user_arg = (void __user*) arg;
318
319         mutex_lock(&minors_lock);
320         dev = hidraw_table[minor];
321         if (!dev) {
322                 ret = -ENODEV;
323                 goto out;
324         }
325
326         switch (cmd) {
327                 case HIDIOCGRDESCSIZE:
328                         if (put_user(dev->hid->rsize, (int __user *)arg))
329                                 ret = -EFAULT;
330                         break;
331
332                 case HIDIOCGRDESC:
333                         {
334                                 __u32 len;
335
336                                 if (get_user(len, (int __user *)arg))
337                                         ret = -EFAULT;
338                                 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
339                                         ret = -EINVAL;
340                                 else if (copy_to_user(user_arg + offsetof(
341                                         struct hidraw_report_descriptor,
342                                         value[0]),
343                                         dev->hid->rdesc,
344                                         min(dev->hid->rsize, len)))
345                                         ret = -EFAULT;
346                                 break;
347                         }
348                 case HIDIOCGRAWINFO:
349                         {
350                                 struct hidraw_devinfo dinfo;
351
352                                 dinfo.bustype = dev->hid->bus;
353                                 dinfo.vendor = dev->hid->vendor;
354                                 dinfo.product = dev->hid->product;
355                                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
356                                         ret = -EFAULT;
357                                 break;
358                         }
359                 default:
360                         {
361                                 struct hid_device *hid = dev->hid;
362                                 if (_IOC_TYPE(cmd) != 'H') {
363                                         ret = -EINVAL;
364                                         break;
365                                 }
366
367                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
368                                         int len = _IOC_SIZE(cmd);
369                                         ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
370                                         break;
371                                 }
372                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
373                                         int len = _IOC_SIZE(cmd);
374                                         ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
375                                         break;
376                                 }
377
378                                 /* Begin Read-only ioctls. */
379                                 if (_IOC_DIR(cmd) != _IOC_READ) {
380                                         ret = -EINVAL;
381                                         break;
382                                 }
383
384                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
385                                         int len = strlen(hid->name) + 1;
386                                         if (len > _IOC_SIZE(cmd))
387                                                 len = _IOC_SIZE(cmd);
388                                         ret = copy_to_user(user_arg, hid->name, len) ?
389                                                 -EFAULT : len;
390                                         break;
391                                 }
392
393                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
394                                         int len = strlen(hid->phys) + 1;
395                                         if (len > _IOC_SIZE(cmd))
396                                                 len = _IOC_SIZE(cmd);
397                                         ret = copy_to_user(user_arg, hid->phys, len) ?
398                                                 -EFAULT : len;
399                                         break;
400                                 }
401                         }
402
403                 ret = -ENOTTY;
404         }
405 out:
406         mutex_unlock(&minors_lock);
407         return ret;
408 }
409
410 static const struct file_operations hidraw_ops = {
411         .owner =        THIS_MODULE,
412         .read =         hidraw_read,
413         .write =        hidraw_write,
414         .poll =         hidraw_poll,
415         .open =         hidraw_open,
416         .release =      hidraw_release,
417         .unlocked_ioctl = hidraw_ioctl,
418 #ifdef CONFIG_COMPAT
419         .compat_ioctl   = hidraw_ioctl,
420 #endif
421         .llseek =       noop_llseek,
422 };
423
424 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
425 {
426         struct hidraw *dev = hid->hidraw;
427         struct hidraw_list *list;
428         int ret = 0;
429
430         list_for_each_entry(list, &dev->list, node) {
431                 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
432
433                 if (new_head == list->tail)
434                         continue;
435
436                 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
437                         ret = -ENOMEM;
438                         break;
439                 }
440                 list->buffer[list->head].len = len;
441                 list->head = new_head;
442                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
443         }
444
445         wake_up_interruptible(&dev->wait);
446         return ret;
447 }
448 EXPORT_SYMBOL_GPL(hidraw_report_event);
449
450 int hidraw_connect(struct hid_device *hid)
451 {
452         int minor, result;
453         struct hidraw *dev;
454
455         /* we accept any HID device, no matter the applications */
456
457         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
458         if (!dev)
459                 return -ENOMEM;
460
461         result = -EINVAL;
462
463         mutex_lock(&minors_lock);
464
465         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
466                 if (hidraw_table[minor])
467                         continue;
468                 hidraw_table[minor] = dev;
469                 result = 0;
470                 break;
471         }
472
473         if (result) {
474                 mutex_unlock(&minors_lock);
475                 kfree(dev);
476                 goto out;
477         }
478
479         dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
480                                  NULL, "%s%d", "hidraw", minor);
481
482         if (IS_ERR(dev->dev)) {
483                 hidraw_table[minor] = NULL;
484                 mutex_unlock(&minors_lock);
485                 result = PTR_ERR(dev->dev);
486                 kfree(dev);
487                 goto out;
488         }
489
490         mutex_unlock(&minors_lock);
491         init_waitqueue_head(&dev->wait);
492         INIT_LIST_HEAD(&dev->list);
493
494         dev->hid = hid;
495         dev->minor = minor;
496
497         dev->exist = 1;
498         hid->hidraw = dev;
499
500 out:
501         return result;
502
503 }
504 EXPORT_SYMBOL_GPL(hidraw_connect);
505
506 void hidraw_disconnect(struct hid_device *hid)
507 {
508         struct hidraw *hidraw = hid->hidraw;
509         drop_ref(hidraw, 1);
510 }
511 EXPORT_SYMBOL_GPL(hidraw_disconnect);
512
513 int __init hidraw_init(void)
514 {
515         int result;
516         dev_t dev_id;
517
518         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
519                         HIDRAW_MAX_DEVICES, "hidraw");
520
521         hidraw_major = MAJOR(dev_id);
522
523         if (result < 0) {
524                 pr_warn("can't get major number\n");
525                 goto out;
526         }
527
528         hidraw_class = class_create(THIS_MODULE, "hidraw");
529         if (IS_ERR(hidraw_class)) {
530                 result = PTR_ERR(hidraw_class);
531                 goto error_cdev;
532         }
533
534         cdev_init(&hidraw_cdev, &hidraw_ops);
535         result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
536         if (result < 0)
537                 goto error_class;
538
539 out:
540         return result;
541
542 error_class:
543         class_destroy(hidraw_class);
544 error_cdev:
545         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
546         goto out;
547 }
548
549 void hidraw_exit(void)
550 {
551         dev_t dev_id = MKDEV(hidraw_major, 0);
552
553         cdev_del(&hidraw_cdev);
554         class_destroy(hidraw_class);
555         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
556
557 }
558
559 static void drop_ref(struct hidraw *hidraw, int exists_bit)
560 {
561         mutex_lock(&minors_lock);
562         if (exists_bit) {
563                 hid_hw_close(hidraw->hid);
564                 hidraw->exist = 0;
565                 if (hidraw->open)
566                         wake_up_interruptible(&hidraw->wait);
567         } else {
568                 --hidraw->open;
569         }
570
571         if (!hidraw->open && !hidraw->exist) {
572                 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
573                 hidraw_table[hidraw->minor] = NULL;
574                 kfree(hidraw);
575         }
576         mutex_unlock(&minors_lock);
577 }