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