Merge branch 'for-rmk/samsung6' of git://git.fluff.org/bjdooks/linux into devel-stable
[linux-2.6.git] / drivers / input / evdev.c
1 /*
2  * Event char devices, giving access to raw input device events.
3  *
4  * Copyright (c) 1999-2002 Vojtech Pavlik
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published by
8  * the Free Software Foundation.
9  */
10
11 #define EVDEV_MINOR_BASE        64
12 #define EVDEV_MINORS            32
13 #define EVDEV_BUFFER_SIZE       64
14
15 #include <linux/poll.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/input.h>
21 #include <linux/major.h>
22 #include <linux/device.h>
23 #include "input-compat.h"
24
25 struct evdev {
26         int exist;
27         int open;
28         int minor;
29         struct input_handle handle;
30         wait_queue_head_t wait;
31         struct evdev_client *grab;
32         struct list_head client_list;
33         spinlock_t client_lock; /* protects client_list */
34         struct mutex mutex;
35         struct device dev;
36 };
37
38 struct evdev_client {
39         struct input_event buffer[EVDEV_BUFFER_SIZE];
40         int head;
41         int tail;
42         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
43         struct fasync_struct *fasync;
44         struct evdev *evdev;
45         struct list_head node;
46 };
47
48 static struct evdev *evdev_table[EVDEV_MINORS];
49 static DEFINE_MUTEX(evdev_table_mutex);
50
51 static void evdev_pass_event(struct evdev_client *client,
52                              struct input_event *event)
53 {
54         /*
55          * Interrupts are disabled, just acquire the lock
56          */
57         spin_lock(&client->buffer_lock);
58         client->buffer[client->head++] = *event;
59         client->head &= EVDEV_BUFFER_SIZE - 1;
60         spin_unlock(&client->buffer_lock);
61
62         if (event->type == EV_SYN)
63                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
64 }
65
66 /*
67  * Pass incoming event to all connected clients.
68  */
69 static void evdev_event(struct input_handle *handle,
70                         unsigned int type, unsigned int code, int value)
71 {
72         struct evdev *evdev = handle->private;
73         struct evdev_client *client;
74         struct input_event event;
75
76         do_gettimeofday(&event.time);
77         event.type = type;
78         event.code = code;
79         event.value = value;
80
81         rcu_read_lock();
82
83         client = rcu_dereference(evdev->grab);
84         if (client)
85                 evdev_pass_event(client, &event);
86         else
87                 list_for_each_entry_rcu(client, &evdev->client_list, node)
88                         evdev_pass_event(client, &event);
89
90         rcu_read_unlock();
91
92         wake_up_interruptible(&evdev->wait);
93 }
94
95 static int evdev_fasync(int fd, struct file *file, int on)
96 {
97         struct evdev_client *client = file->private_data;
98
99         return fasync_helper(fd, file, on, &client->fasync);
100 }
101
102 static int evdev_flush(struct file *file, fl_owner_t id)
103 {
104         struct evdev_client *client = file->private_data;
105         struct evdev *evdev = client->evdev;
106         int retval;
107
108         retval = mutex_lock_interruptible(&evdev->mutex);
109         if (retval)
110                 return retval;
111
112         if (!evdev->exist)
113                 retval = -ENODEV;
114         else
115                 retval = input_flush_device(&evdev->handle, file);
116
117         mutex_unlock(&evdev->mutex);
118         return retval;
119 }
120
121 static void evdev_free(struct device *dev)
122 {
123         struct evdev *evdev = container_of(dev, struct evdev, dev);
124
125         input_put_device(evdev->handle.dev);
126         kfree(evdev);
127 }
128
129 /*
130  * Grabs an event device (along with underlying input device).
131  * This function is called with evdev->mutex taken.
132  */
133 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
134 {
135         int error;
136
137         if (evdev->grab)
138                 return -EBUSY;
139
140         error = input_grab_device(&evdev->handle);
141         if (error)
142                 return error;
143
144         rcu_assign_pointer(evdev->grab, client);
145         synchronize_rcu();
146
147         return 0;
148 }
149
150 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
151 {
152         if (evdev->grab != client)
153                 return  -EINVAL;
154
155         rcu_assign_pointer(evdev->grab, NULL);
156         synchronize_rcu();
157         input_release_device(&evdev->handle);
158
159         return 0;
160 }
161
162 static void evdev_attach_client(struct evdev *evdev,
163                                 struct evdev_client *client)
164 {
165         spin_lock(&evdev->client_lock);
166         list_add_tail_rcu(&client->node, &evdev->client_list);
167         spin_unlock(&evdev->client_lock);
168         synchronize_rcu();
169 }
170
171 static void evdev_detach_client(struct evdev *evdev,
172                                 struct evdev_client *client)
173 {
174         spin_lock(&evdev->client_lock);
175         list_del_rcu(&client->node);
176         spin_unlock(&evdev->client_lock);
177         synchronize_rcu();
178 }
179
180 static int evdev_open_device(struct evdev *evdev)
181 {
182         int retval;
183
184         retval = mutex_lock_interruptible(&evdev->mutex);
185         if (retval)
186                 return retval;
187
188         if (!evdev->exist)
189                 retval = -ENODEV;
190         else if (!evdev->open++) {
191                 retval = input_open_device(&evdev->handle);
192                 if (retval)
193                         evdev->open--;
194         }
195
196         mutex_unlock(&evdev->mutex);
197         return retval;
198 }
199
200 static void evdev_close_device(struct evdev *evdev)
201 {
202         mutex_lock(&evdev->mutex);
203
204         if (evdev->exist && !--evdev->open)
205                 input_close_device(&evdev->handle);
206
207         mutex_unlock(&evdev->mutex);
208 }
209
210 /*
211  * Wake up users waiting for IO so they can disconnect from
212  * dead device.
213  */
214 static void evdev_hangup(struct evdev *evdev)
215 {
216         struct evdev_client *client;
217
218         spin_lock(&evdev->client_lock);
219         list_for_each_entry(client, &evdev->client_list, node)
220                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
221         spin_unlock(&evdev->client_lock);
222
223         wake_up_interruptible(&evdev->wait);
224 }
225
226 static int evdev_release(struct inode *inode, struct file *file)
227 {
228         struct evdev_client *client = file->private_data;
229         struct evdev *evdev = client->evdev;
230
231         mutex_lock(&evdev->mutex);
232         if (evdev->grab == client)
233                 evdev_ungrab(evdev, client);
234         mutex_unlock(&evdev->mutex);
235
236         evdev_detach_client(evdev, client);
237         kfree(client);
238
239         evdev_close_device(evdev);
240         put_device(&evdev->dev);
241
242         return 0;
243 }
244
245 static int evdev_open(struct inode *inode, struct file *file)
246 {
247         struct evdev *evdev;
248         struct evdev_client *client;
249         int i = iminor(inode) - EVDEV_MINOR_BASE;
250         int error;
251
252         if (i >= EVDEV_MINORS)
253                 return -ENODEV;
254
255         error = mutex_lock_interruptible(&evdev_table_mutex);
256         if (error)
257                 return error;
258         evdev = evdev_table[i];
259         if (evdev)
260                 get_device(&evdev->dev);
261         mutex_unlock(&evdev_table_mutex);
262
263         if (!evdev)
264                 return -ENODEV;
265
266         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
267         if (!client) {
268                 error = -ENOMEM;
269                 goto err_put_evdev;
270         }
271
272         spin_lock_init(&client->buffer_lock);
273         client->evdev = evdev;
274         evdev_attach_client(evdev, client);
275
276         error = evdev_open_device(evdev);
277         if (error)
278                 goto err_free_client;
279
280         file->private_data = client;
281         return 0;
282
283  err_free_client:
284         evdev_detach_client(evdev, client);
285         kfree(client);
286  err_put_evdev:
287         put_device(&evdev->dev);
288         return error;
289 }
290
291 static ssize_t evdev_write(struct file *file, const char __user *buffer,
292                            size_t count, loff_t *ppos)
293 {
294         struct evdev_client *client = file->private_data;
295         struct evdev *evdev = client->evdev;
296         struct input_event event;
297         int retval;
298
299         retval = mutex_lock_interruptible(&evdev->mutex);
300         if (retval)
301                 return retval;
302
303         if (!evdev->exist) {
304                 retval = -ENODEV;
305                 goto out;
306         }
307
308         while (retval < count) {
309
310                 if (input_event_from_user(buffer + retval, &event)) {
311                         retval = -EFAULT;
312                         goto out;
313                 }
314
315                 input_inject_event(&evdev->handle,
316                                    event.type, event.code, event.value);
317                 retval += input_event_size();
318         }
319
320  out:
321         mutex_unlock(&evdev->mutex);
322         return retval;
323 }
324
325 static int evdev_fetch_next_event(struct evdev_client *client,
326                                   struct input_event *event)
327 {
328         int have_event;
329
330         spin_lock_irq(&client->buffer_lock);
331
332         have_event = client->head != client->tail;
333         if (have_event) {
334                 *event = client->buffer[client->tail++];
335                 client->tail &= EVDEV_BUFFER_SIZE - 1;
336         }
337
338         spin_unlock_irq(&client->buffer_lock);
339
340         return have_event;
341 }
342
343 static ssize_t evdev_read(struct file *file, char __user *buffer,
344                           size_t count, loff_t *ppos)
345 {
346         struct evdev_client *client = file->private_data;
347         struct evdev *evdev = client->evdev;
348         struct input_event event;
349         int retval;
350
351         if (count < input_event_size())
352                 return -EINVAL;
353
354         if (client->head == client->tail && evdev->exist &&
355             (file->f_flags & O_NONBLOCK))
356                 return -EAGAIN;
357
358         retval = wait_event_interruptible(evdev->wait,
359                 client->head != client->tail || !evdev->exist);
360         if (retval)
361                 return retval;
362
363         if (!evdev->exist)
364                 return -ENODEV;
365
366         while (retval + input_event_size() <= count &&
367                evdev_fetch_next_event(client, &event)) {
368
369                 if (input_event_to_user(buffer + retval, &event))
370                         return -EFAULT;
371
372                 retval += input_event_size();
373         }
374
375         return retval;
376 }
377
378 /* No kernel lock - fine */
379 static unsigned int evdev_poll(struct file *file, poll_table *wait)
380 {
381         struct evdev_client *client = file->private_data;
382         struct evdev *evdev = client->evdev;
383
384         poll_wait(file, &evdev->wait, wait);
385         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
386                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
387 }
388
389 #ifdef CONFIG_COMPAT
390
391 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
392 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
393
394 #ifdef __BIG_ENDIAN
395 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
396                         unsigned int maxlen, void __user *p, int compat)
397 {
398         int len, i;
399
400         if (compat) {
401                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
402                 if (len > maxlen)
403                         len = maxlen;
404
405                 for (i = 0; i < len / sizeof(compat_long_t); i++)
406                         if (copy_to_user((compat_long_t __user *) p + i,
407                                          (compat_long_t *) bits +
408                                                 i + 1 - ((i % 2) << 1),
409                                          sizeof(compat_long_t)))
410                                 return -EFAULT;
411         } else {
412                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
413                 if (len > maxlen)
414                         len = maxlen;
415
416                 if (copy_to_user(p, bits, len))
417                         return -EFAULT;
418         }
419
420         return len;
421 }
422 #else
423 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
424                         unsigned int maxlen, void __user *p, int compat)
425 {
426         int len = compat ?
427                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
428                         BITS_TO_LONGS(maxbit) * sizeof(long);
429
430         if (len > maxlen)
431                 len = maxlen;
432
433         return copy_to_user(p, bits, len) ? -EFAULT : len;
434 }
435 #endif /* __BIG_ENDIAN */
436
437 #else
438
439 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
440                         unsigned int maxlen, void __user *p, int compat)
441 {
442         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
443
444         if (len > maxlen)
445                 len = maxlen;
446
447         return copy_to_user(p, bits, len) ? -EFAULT : len;
448 }
449
450 #endif /* CONFIG_COMPAT */
451
452 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
453 {
454         int len;
455
456         if (!str)
457                 return -ENOENT;
458
459         len = strlen(str) + 1;
460         if (len > maxlen)
461                 len = maxlen;
462
463         return copy_to_user(p, str, len) ? -EFAULT : len;
464 }
465
466 #define OLD_KEY_MAX     0x1ff
467 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
468 {
469         static unsigned long keymax_warn_time;
470         unsigned long *bits;
471         int len;
472
473         switch (_IOC_NR(cmd) & EV_MAX) {
474
475         case      0: bits = dev->evbit;  len = EV_MAX;  break;
476         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
477         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
478         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
479         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
480         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
481         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
482         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
483         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
484         default: return -EINVAL;
485         }
486
487         /*
488          * Work around bugs in userspace programs that like to do
489          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
490          * should be in bytes, not in bits.
491          */
492         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
493                 len = OLD_KEY_MAX;
494                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
495                         printk(KERN_WARNING
496                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
497                                 "limiting output to %zu bytes. See "
498                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
499                                 OLD_KEY_MAX,
500                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
501         }
502
503         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
504 }
505 #undef OLD_KEY_MAX
506
507 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
508                            void __user *p, int compat_mode)
509 {
510         struct evdev_client *client = file->private_data;
511         struct evdev *evdev = client->evdev;
512         struct input_dev *dev = evdev->handle.dev;
513         struct input_absinfo abs;
514         struct ff_effect effect;
515         int __user *ip = (int __user *)p;
516         int i, t, u, v;
517         int error;
518
519         switch (cmd) {
520
521         case EVIOCGVERSION:
522                 return put_user(EV_VERSION, ip);
523
524         case EVIOCGID:
525                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
526                         return -EFAULT;
527                 return 0;
528
529         case EVIOCGREP:
530                 if (!test_bit(EV_REP, dev->evbit))
531                         return -ENOSYS;
532                 if (put_user(dev->rep[REP_DELAY], ip))
533                         return -EFAULT;
534                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
535                         return -EFAULT;
536                 return 0;
537
538         case EVIOCSREP:
539                 if (!test_bit(EV_REP, dev->evbit))
540                         return -ENOSYS;
541                 if (get_user(u, ip))
542                         return -EFAULT;
543                 if (get_user(v, ip + 1))
544                         return -EFAULT;
545
546                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
547                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
548
549                 return 0;
550
551         case EVIOCGKEYCODE:
552                 if (get_user(t, ip))
553                         return -EFAULT;
554
555                 error = input_get_keycode(dev, t, &v);
556                 if (error)
557                         return error;
558
559                 if (put_user(v, ip + 1))
560                         return -EFAULT;
561
562                 return 0;
563
564         case EVIOCSKEYCODE:
565                 if (get_user(t, ip) || get_user(v, ip + 1))
566                         return -EFAULT;
567
568                 return input_set_keycode(dev, t, v);
569
570         case EVIOCRMFF:
571                 return input_ff_erase(dev, (int)(unsigned long) p, file);
572
573         case EVIOCGEFFECTS:
574                 i = test_bit(EV_FF, dev->evbit) ?
575                                 dev->ff->max_effects : 0;
576                 if (put_user(i, ip))
577                         return -EFAULT;
578                 return 0;
579
580         case EVIOCGRAB:
581                 if (p)
582                         return evdev_grab(evdev, client);
583                 else
584                         return evdev_ungrab(evdev, client);
585
586         default:
587
588                 if (_IOC_TYPE(cmd) != 'E')
589                         return -EINVAL;
590
591                 if (_IOC_DIR(cmd) == _IOC_READ) {
592
593                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
594                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
595
596                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
597                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
598                                                     p, compat_mode);
599
600                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
601                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
602                                                     p, compat_mode);
603
604                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
605                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
606                                                     p, compat_mode);
607
608                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
609                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
610                                                     p, compat_mode);
611
612                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
613                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
614
615                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
616                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
617
618                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
619                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
620
621                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
622
623                                 t = _IOC_NR(cmd) & ABS_MAX;
624
625                                 abs.value = dev->abs[t];
626                                 abs.minimum = dev->absmin[t];
627                                 abs.maximum = dev->absmax[t];
628                                 abs.fuzz = dev->absfuzz[t];
629                                 abs.flat = dev->absflat[t];
630                                 abs.resolution = dev->absres[t];
631
632                                 if (copy_to_user(p, &abs, min_t(size_t,
633                                                                 _IOC_SIZE(cmd),
634                                                                 sizeof(struct input_absinfo))))
635                                         return -EFAULT;
636
637                                 return 0;
638                         }
639
640                 }
641
642                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
643
644                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
645
646                                 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
647                                         return -EFAULT;
648
649                                 error = input_ff_upload(dev, &effect, file);
650
651                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
652                                         return -EFAULT;
653
654                                 return error;
655                         }
656
657                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
658
659                                 t = _IOC_NR(cmd) & ABS_MAX;
660
661                                 if (copy_from_user(&abs, p, min_t(size_t,
662                                                                   _IOC_SIZE(cmd),
663                                                                   sizeof(struct input_absinfo))))
664                                         return -EFAULT;
665
666                                 /*
667                                  * Take event lock to ensure that we are not
668                                  * changing device parameters in the middle
669                                  * of event.
670                                  */
671                                 spin_lock_irq(&dev->event_lock);
672
673                                 dev->abs[t] = abs.value;
674                                 dev->absmin[t] = abs.minimum;
675                                 dev->absmax[t] = abs.maximum;
676                                 dev->absfuzz[t] = abs.fuzz;
677                                 dev->absflat[t] = abs.flat;
678                                 dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
679                                                         0 : abs.resolution;
680
681                                 spin_unlock_irq(&dev->event_lock);
682
683                                 return 0;
684                         }
685                 }
686         }
687         return -EINVAL;
688 }
689
690 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
691                                 void __user *p, int compat_mode)
692 {
693         struct evdev_client *client = file->private_data;
694         struct evdev *evdev = client->evdev;
695         int retval;
696
697         retval = mutex_lock_interruptible(&evdev->mutex);
698         if (retval)
699                 return retval;
700
701         if (!evdev->exist) {
702                 retval = -ENODEV;
703                 goto out;
704         }
705
706         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
707
708  out:
709         mutex_unlock(&evdev->mutex);
710         return retval;
711 }
712
713 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
714 {
715         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
716 }
717
718 #ifdef CONFIG_COMPAT
719 static long evdev_ioctl_compat(struct file *file,
720                                 unsigned int cmd, unsigned long arg)
721 {
722         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
723 }
724 #endif
725
726 static const struct file_operations evdev_fops = {
727         .owner          = THIS_MODULE,
728         .read           = evdev_read,
729         .write          = evdev_write,
730         .poll           = evdev_poll,
731         .open           = evdev_open,
732         .release        = evdev_release,
733         .unlocked_ioctl = evdev_ioctl,
734 #ifdef CONFIG_COMPAT
735         .compat_ioctl   = evdev_ioctl_compat,
736 #endif
737         .fasync         = evdev_fasync,
738         .flush          = evdev_flush
739 };
740
741 static int evdev_install_chrdev(struct evdev *evdev)
742 {
743         /*
744          * No need to do any locking here as calls to connect and
745          * disconnect are serialized by the input core
746          */
747         evdev_table[evdev->minor] = evdev;
748         return 0;
749 }
750
751 static void evdev_remove_chrdev(struct evdev *evdev)
752 {
753         /*
754          * Lock evdev table to prevent race with evdev_open()
755          */
756         mutex_lock(&evdev_table_mutex);
757         evdev_table[evdev->minor] = NULL;
758         mutex_unlock(&evdev_table_mutex);
759 }
760
761 /*
762  * Mark device non-existent. This disables writes, ioctls and
763  * prevents new users from opening the device. Already posted
764  * blocking reads will stay, however new ones will fail.
765  */
766 static void evdev_mark_dead(struct evdev *evdev)
767 {
768         mutex_lock(&evdev->mutex);
769         evdev->exist = 0;
770         mutex_unlock(&evdev->mutex);
771 }
772
773 static void evdev_cleanup(struct evdev *evdev)
774 {
775         struct input_handle *handle = &evdev->handle;
776
777         evdev_mark_dead(evdev);
778         evdev_hangup(evdev);
779         evdev_remove_chrdev(evdev);
780
781         /* evdev is marked dead so no one else accesses evdev->open */
782         if (evdev->open) {
783                 input_flush_device(handle, NULL);
784                 input_close_device(handle);
785         }
786 }
787
788 /*
789  * Create new evdev device. Note that input core serializes calls
790  * to connect and disconnect so we don't need to lock evdev_table here.
791  */
792 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
793                          const struct input_device_id *id)
794 {
795         struct evdev *evdev;
796         int minor;
797         int error;
798
799         for (minor = 0; minor < EVDEV_MINORS; minor++)
800                 if (!evdev_table[minor])
801                         break;
802
803         if (minor == EVDEV_MINORS) {
804                 printk(KERN_ERR "evdev: no more free evdev devices\n");
805                 return -ENFILE;
806         }
807
808         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
809         if (!evdev)
810                 return -ENOMEM;
811
812         INIT_LIST_HEAD(&evdev->client_list);
813         spin_lock_init(&evdev->client_lock);
814         mutex_init(&evdev->mutex);
815         init_waitqueue_head(&evdev->wait);
816
817         dev_set_name(&evdev->dev, "event%d", minor);
818         evdev->exist = 1;
819         evdev->minor = minor;
820
821         evdev->handle.dev = input_get_device(dev);
822         evdev->handle.name = dev_name(&evdev->dev);
823         evdev->handle.handler = handler;
824         evdev->handle.private = evdev;
825
826         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
827         evdev->dev.class = &input_class;
828         evdev->dev.parent = &dev->dev;
829         evdev->dev.release = evdev_free;
830         device_initialize(&evdev->dev);
831
832         error = input_register_handle(&evdev->handle);
833         if (error)
834                 goto err_free_evdev;
835
836         error = evdev_install_chrdev(evdev);
837         if (error)
838                 goto err_unregister_handle;
839
840         error = device_add(&evdev->dev);
841         if (error)
842                 goto err_cleanup_evdev;
843
844         return 0;
845
846  err_cleanup_evdev:
847         evdev_cleanup(evdev);
848  err_unregister_handle:
849         input_unregister_handle(&evdev->handle);
850  err_free_evdev:
851         put_device(&evdev->dev);
852         return error;
853 }
854
855 static void evdev_disconnect(struct input_handle *handle)
856 {
857         struct evdev *evdev = handle->private;
858
859         device_del(&evdev->dev);
860         evdev_cleanup(evdev);
861         input_unregister_handle(handle);
862         put_device(&evdev->dev);
863 }
864
865 static const struct input_device_id evdev_ids[] = {
866         { .driver_info = 1 },   /* Matches all devices */
867         { },                    /* Terminating zero entry */
868 };
869
870 MODULE_DEVICE_TABLE(input, evdev_ids);
871
872 static struct input_handler evdev_handler = {
873         .event          = evdev_event,
874         .connect        = evdev_connect,
875         .disconnect     = evdev_disconnect,
876         .fops           = &evdev_fops,
877         .minor          = EVDEV_MINOR_BASE,
878         .name           = "evdev",
879         .id_table       = evdev_ids,
880 };
881
882 static int __init evdev_init(void)
883 {
884         return input_register_handler(&evdev_handler);
885 }
886
887 static void __exit evdev_exit(void)
888 {
889         input_unregister_handler(&evdev_handler);
890 }
891
892 module_init(evdev_init);
893 module_exit(evdev_exit);
894
895 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
896 MODULE_DESCRIPTION("Input driver event char devices");
897 MODULE_LICENSE("GPL");