c69a58fe54d8baaaab62147ebcd2f8ca7a364422
[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/slab.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/input.h>
20 #include <linux/major.h>
21 #include <linux/device.h>
22 #include "input-compat.h"
23
24 struct evdev {
25         int exist;
26         int open;
27         int minor;
28         char name[16];
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         kill_fasync(&client->fasync, SIGIO, POLL_IN);
63 }
64
65 /*
66  * Pass incoming event to all connected clients.
67  */
68 static void evdev_event(struct input_handle *handle,
69                         unsigned int type, unsigned int code, int value)
70 {
71         struct evdev *evdev = handle->private;
72         struct evdev_client *client;
73         struct input_event event;
74
75         do_gettimeofday(&event.time);
76         event.type = type;
77         event.code = code;
78         event.value = value;
79
80         rcu_read_lock();
81
82         client = rcu_dereference(evdev->grab);
83         if (client)
84                 evdev_pass_event(client, &event);
85         else
86                 list_for_each_entry_rcu(client, &evdev->client_list, node)
87                         evdev_pass_event(client, &event);
88
89         rcu_read_unlock();
90
91         wake_up_interruptible(&evdev->wait);
92 }
93
94 static int evdev_fasync(int fd, struct file *file, int on)
95 {
96         struct evdev_client *client = file->private_data;
97         int retval;
98
99         retval = fasync_helper(fd, file, on, &client->fasync);
100
101         return retval < 0 ? retval : 0;
102 }
103
104 static int evdev_flush(struct file *file, fl_owner_t id)
105 {
106         struct evdev_client *client = file->private_data;
107         struct evdev *evdev = client->evdev;
108         int retval;
109
110         retval = mutex_lock_interruptible(&evdev->mutex);
111         if (retval)
112                 return retval;
113
114         if (!evdev->exist)
115                 retval = -ENODEV;
116         else
117                 retval = input_flush_device(&evdev->handle, file);
118
119         mutex_unlock(&evdev->mutex);
120         return retval;
121 }
122
123 static void evdev_free(struct device *dev)
124 {
125         struct evdev *evdev = container_of(dev, struct evdev, dev);
126
127         input_put_device(evdev->handle.dev);
128         kfree(evdev);
129 }
130
131 /*
132  * Grabs an event device (along with underlying input device).
133  * This function is called with evdev->mutex taken.
134  */
135 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
136 {
137         int error;
138
139         if (evdev->grab)
140                 return -EBUSY;
141
142         error = input_grab_device(&evdev->handle);
143         if (error)
144                 return error;
145
146         rcu_assign_pointer(evdev->grab, client);
147         synchronize_rcu();
148
149         return 0;
150 }
151
152 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
153 {
154         if (evdev->grab != client)
155                 return  -EINVAL;
156
157         rcu_assign_pointer(evdev->grab, NULL);
158         synchronize_rcu();
159         input_release_device(&evdev->handle);
160
161         return 0;
162 }
163
164 static void evdev_attach_client(struct evdev *evdev,
165                                 struct evdev_client *client)
166 {
167         spin_lock(&evdev->client_lock);
168         list_add_tail_rcu(&client->node, &evdev->client_list);
169         spin_unlock(&evdev->client_lock);
170         synchronize_rcu();
171 }
172
173 static void evdev_detach_client(struct evdev *evdev,
174                                 struct evdev_client *client)
175 {
176         spin_lock(&evdev->client_lock);
177         list_del_rcu(&client->node);
178         spin_unlock(&evdev->client_lock);
179         synchronize_rcu();
180 }
181
182 static int evdev_open_device(struct evdev *evdev)
183 {
184         int retval;
185
186         retval = mutex_lock_interruptible(&evdev->mutex);
187         if (retval)
188                 return retval;
189
190         if (!evdev->exist)
191                 retval = -ENODEV;
192         else if (!evdev->open++) {
193                 retval = input_open_device(&evdev->handle);
194                 if (retval)
195                         evdev->open--;
196         }
197
198         mutex_unlock(&evdev->mutex);
199         return retval;
200 }
201
202 static void evdev_close_device(struct evdev *evdev)
203 {
204         mutex_lock(&evdev->mutex);
205
206         if (evdev->exist && !--evdev->open)
207                 input_close_device(&evdev->handle);
208
209         mutex_unlock(&evdev->mutex);
210 }
211
212 /*
213  * Wake up users waiting for IO so they can disconnect from
214  * dead device.
215  */
216 static void evdev_hangup(struct evdev *evdev)
217 {
218         struct evdev_client *client;
219
220         spin_lock(&evdev->client_lock);
221         list_for_each_entry(client, &evdev->client_list, node)
222                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
223         spin_unlock(&evdev->client_lock);
224
225         wake_up_interruptible(&evdev->wait);
226 }
227
228 static int evdev_release(struct inode *inode, struct file *file)
229 {
230         struct evdev_client *client = file->private_data;
231         struct evdev *evdev = client->evdev;
232
233         mutex_lock(&evdev->mutex);
234         if (evdev->grab == client)
235                 evdev_ungrab(evdev, client);
236         mutex_unlock(&evdev->mutex);
237
238         evdev_fasync(-1, file, 0);
239         evdev_detach_client(evdev, client);
240         kfree(client);
241
242         evdev_close_device(evdev);
243         put_device(&evdev->dev);
244
245         return 0;
246 }
247
248 static int evdev_open(struct inode *inode, struct file *file)
249 {
250         struct evdev *evdev;
251         struct evdev_client *client;
252         int i = iminor(inode) - EVDEV_MINOR_BASE;
253         int error;
254
255         if (i >= EVDEV_MINORS)
256                 return -ENODEV;
257
258         error = mutex_lock_interruptible(&evdev_table_mutex);
259         if (error)
260                 return error;
261         evdev = evdev_table[i];
262         if (evdev)
263                 get_device(&evdev->dev);
264         mutex_unlock(&evdev_table_mutex);
265
266         if (!evdev)
267                 return -ENODEV;
268
269         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
270         if (!client) {
271                 error = -ENOMEM;
272                 goto err_put_evdev;
273         }
274
275         spin_lock_init(&client->buffer_lock);
276         client->evdev = evdev;
277         evdev_attach_client(evdev, client);
278
279         error = evdev_open_device(evdev);
280         if (error)
281                 goto err_free_client;
282
283         file->private_data = client;
284         return 0;
285
286  err_free_client:
287         evdev_detach_client(evdev, client);
288         kfree(client);
289  err_put_evdev:
290         put_device(&evdev->dev);
291         return error;
292 }
293
294 static ssize_t evdev_write(struct file *file, const char __user *buffer,
295                            size_t count, loff_t *ppos)
296 {
297         struct evdev_client *client = file->private_data;
298         struct evdev *evdev = client->evdev;
299         struct input_event event;
300         int retval;
301
302         retval = mutex_lock_interruptible(&evdev->mutex);
303         if (retval)
304                 return retval;
305
306         if (!evdev->exist) {
307                 retval = -ENODEV;
308                 goto out;
309         }
310
311         while (retval < count) {
312
313                 if (input_event_from_user(buffer + retval, &event)) {
314                         retval = -EFAULT;
315                         goto out;
316                 }
317
318                 input_inject_event(&evdev->handle,
319                                    event.type, event.code, event.value);
320                 retval += input_event_size();
321         }
322
323  out:
324         mutex_unlock(&evdev->mutex);
325         return retval;
326 }
327
328 static int evdev_fetch_next_event(struct evdev_client *client,
329                                   struct input_event *event)
330 {
331         int have_event;
332
333         spin_lock_irq(&client->buffer_lock);
334
335         have_event = client->head != client->tail;
336         if (have_event) {
337                 *event = client->buffer[client->tail++];
338                 client->tail &= EVDEV_BUFFER_SIZE - 1;
339         }
340
341         spin_unlock_irq(&client->buffer_lock);
342
343         return have_event;
344 }
345
346 static ssize_t evdev_read(struct file *file, char __user *buffer,
347                           size_t count, loff_t *ppos)
348 {
349         struct evdev_client *client = file->private_data;
350         struct evdev *evdev = client->evdev;
351         struct input_event event;
352         int retval;
353
354         if (count < input_event_size())
355                 return -EINVAL;
356
357         if (client->head == client->tail && evdev->exist &&
358             (file->f_flags & O_NONBLOCK))
359                 return -EAGAIN;
360
361         retval = wait_event_interruptible(evdev->wait,
362                 client->head != client->tail || !evdev->exist);
363         if (retval)
364                 return retval;
365
366         if (!evdev->exist)
367                 return -ENODEV;
368
369         while (retval + input_event_size() <= count &&
370                evdev_fetch_next_event(client, &event)) {
371
372                 if (input_event_to_user(buffer + retval, &event))
373                         return -EFAULT;
374
375                 retval += input_event_size();
376         }
377
378         return retval;
379 }
380
381 /* No kernel lock - fine */
382 static unsigned int evdev_poll(struct file *file, poll_table *wait)
383 {
384         struct evdev_client *client = file->private_data;
385         struct evdev *evdev = client->evdev;
386
387         poll_wait(file, &evdev->wait, wait);
388         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
389                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
390 }
391
392 #ifdef CONFIG_COMPAT
393
394 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
395 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
396
397 #ifdef __BIG_ENDIAN
398 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
399                         unsigned int maxlen, void __user *p, int compat)
400 {
401         int len, i;
402
403         if (compat) {
404                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
405                 if (len > maxlen)
406                         len = maxlen;
407
408                 for (i = 0; i < len / sizeof(compat_long_t); i++)
409                         if (copy_to_user((compat_long_t __user *) p + i,
410                                          (compat_long_t *) bits +
411                                                 i + 1 - ((i % 2) << 1),
412                                          sizeof(compat_long_t)))
413                                 return -EFAULT;
414         } else {
415                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
416                 if (len > maxlen)
417                         len = maxlen;
418
419                 if (copy_to_user(p, bits, len))
420                         return -EFAULT;
421         }
422
423         return len;
424 }
425 #else
426 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
427                         unsigned int maxlen, void __user *p, int compat)
428 {
429         int len = compat ?
430                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
431                         BITS_TO_LONGS(maxbit) * sizeof(long);
432
433         if (len > maxlen)
434                 len = maxlen;
435
436         return copy_to_user(p, bits, len) ? -EFAULT : len;
437 }
438 #endif /* __BIG_ENDIAN */
439
440 #else
441
442 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
443                         unsigned int maxlen, void __user *p, int compat)
444 {
445         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
446
447         if (len > maxlen)
448                 len = maxlen;
449
450         return copy_to_user(p, bits, len) ? -EFAULT : len;
451 }
452
453 #endif /* CONFIG_COMPAT */
454
455 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
456 {
457         int len;
458
459         if (!str)
460                 return -ENOENT;
461
462         len = strlen(str) + 1;
463         if (len > maxlen)
464                 len = maxlen;
465
466         return copy_to_user(p, str, len) ? -EFAULT : len;
467 }
468
469 #define OLD_KEY_MAX     0x1ff
470 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
471 {
472         static unsigned long keymax_warn_time;
473         unsigned long *bits;
474         int len;
475
476         switch (_IOC_NR(cmd) & EV_MAX) {
477
478         case      0: bits = dev->evbit;  len = EV_MAX;  break;
479         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
480         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
481         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
482         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
483         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
484         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
485         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
486         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
487         default: return -EINVAL;
488         }
489
490         /*
491          * Work around bugs in userspace programs that like to do
492          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
493          * should be in bytes, not in bits.
494          */
495         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
496                 len = OLD_KEY_MAX;
497                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
498                         printk(KERN_WARNING
499                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
500                                 "limiting output to %zu bytes. See "
501                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
502                                 OLD_KEY_MAX,
503                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
504         }
505
506         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
507 }
508 #undef OLD_KEY_MAX
509
510 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
511                            void __user *p, int compat_mode)
512 {
513         struct evdev_client *client = file->private_data;
514         struct evdev *evdev = client->evdev;
515         struct input_dev *dev = evdev->handle.dev;
516         struct input_absinfo abs;
517         struct ff_effect effect;
518         int __user *ip = (int __user *)p;
519         int i, t, u, v;
520         int error;
521
522         switch (cmd) {
523
524         case EVIOCGVERSION:
525                 return put_user(EV_VERSION, ip);
526
527         case EVIOCGID:
528                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
529                         return -EFAULT;
530                 return 0;
531
532         case EVIOCGREP:
533                 if (!test_bit(EV_REP, dev->evbit))
534                         return -ENOSYS;
535                 if (put_user(dev->rep[REP_DELAY], ip))
536                         return -EFAULT;
537                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
538                         return -EFAULT;
539                 return 0;
540
541         case EVIOCSREP:
542                 if (!test_bit(EV_REP, dev->evbit))
543                         return -ENOSYS;
544                 if (get_user(u, ip))
545                         return -EFAULT;
546                 if (get_user(v, ip + 1))
547                         return -EFAULT;
548
549                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
550                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
551
552                 return 0;
553
554         case EVIOCGKEYCODE:
555                 if (get_user(t, ip))
556                         return -EFAULT;
557
558                 error = input_get_keycode(dev, t, &v);
559                 if (error)
560                         return error;
561
562                 if (put_user(v, ip + 1))
563                         return -EFAULT;
564
565                 return 0;
566
567         case EVIOCSKEYCODE:
568                 if (get_user(t, ip) || get_user(v, ip + 1))
569                         return -EFAULT;
570
571                 return input_set_keycode(dev, t, v);
572
573         case EVIOCRMFF:
574                 return input_ff_erase(dev, (int)(unsigned long) p, file);
575
576         case EVIOCGEFFECTS:
577                 i = test_bit(EV_FF, dev->evbit) ?
578                                 dev->ff->max_effects : 0;
579                 if (put_user(i, ip))
580                         return -EFAULT;
581                 return 0;
582
583         case EVIOCGRAB:
584                 if (p)
585                         return evdev_grab(evdev, client);
586                 else
587                         return evdev_ungrab(evdev, client);
588
589         default:
590
591                 if (_IOC_TYPE(cmd) != 'E')
592                         return -EINVAL;
593
594                 if (_IOC_DIR(cmd) == _IOC_READ) {
595
596                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
597                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
598
599                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
600                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
601                                                     p, compat_mode);
602
603                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
604                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
605                                                     p, compat_mode);
606
607                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
608                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
609                                                     p, compat_mode);
610
611                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
612                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
613                                                     p, compat_mode);
614
615                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
616                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
617
618                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
619                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
620
621                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
622                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
623
624                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
625
626                                 t = _IOC_NR(cmd) & ABS_MAX;
627
628                                 abs.value = dev->abs[t];
629                                 abs.minimum = dev->absmin[t];
630                                 abs.maximum = dev->absmax[t];
631                                 abs.fuzz = dev->absfuzz[t];
632                                 abs.flat = dev->absflat[t];
633
634                                 if (copy_to_user(p, &abs, 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,
662                                                 sizeof(struct input_absinfo)))
663                                         return -EFAULT;
664
665                                 /*
666                                  * Take event lock to ensure that we are not
667                                  * changing device parameters in the middle
668                                  * of event.
669                                  */
670                                 spin_lock_irq(&dev->event_lock);
671
672                                 dev->abs[t] = abs.value;
673                                 dev->absmin[t] = abs.minimum;
674                                 dev->absmax[t] = abs.maximum;
675                                 dev->absfuzz[t] = abs.fuzz;
676                                 dev->absflat[t] = abs.flat;
677
678                                 spin_unlock_irq(&dev->event_lock);
679
680                                 return 0;
681                         }
682                 }
683         }
684         return -EINVAL;
685 }
686
687 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
688                                 void __user *p, int compat_mode)
689 {
690         struct evdev_client *client = file->private_data;
691         struct evdev *evdev = client->evdev;
692         int retval;
693
694         retval = mutex_lock_interruptible(&evdev->mutex);
695         if (retval)
696                 return retval;
697
698         if (!evdev->exist) {
699                 retval = -ENODEV;
700                 goto out;
701         }
702
703         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
704
705  out:
706         mutex_unlock(&evdev->mutex);
707         return retval;
708 }
709
710 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
711 {
712         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
713 }
714
715 #ifdef CONFIG_COMPAT
716 static long evdev_ioctl_compat(struct file *file,
717                                 unsigned int cmd, unsigned long arg)
718 {
719         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
720 }
721 #endif
722
723 static const struct file_operations evdev_fops = {
724         .owner          = THIS_MODULE,
725         .read           = evdev_read,
726         .write          = evdev_write,
727         .poll           = evdev_poll,
728         .open           = evdev_open,
729         .release        = evdev_release,
730         .unlocked_ioctl = evdev_ioctl,
731 #ifdef CONFIG_COMPAT
732         .compat_ioctl   = evdev_ioctl_compat,
733 #endif
734         .fasync         = evdev_fasync,
735         .flush          = evdev_flush
736 };
737
738 static int evdev_install_chrdev(struct evdev *evdev)
739 {
740         /*
741          * No need to do any locking here as calls to connect and
742          * disconnect are serialized by the input core
743          */
744         evdev_table[evdev->minor] = evdev;
745         return 0;
746 }
747
748 static void evdev_remove_chrdev(struct evdev *evdev)
749 {
750         /*
751          * Lock evdev table to prevent race with evdev_open()
752          */
753         mutex_lock(&evdev_table_mutex);
754         evdev_table[evdev->minor] = NULL;
755         mutex_unlock(&evdev_table_mutex);
756 }
757
758 /*
759  * Mark device non-existent. This disables writes, ioctls and
760  * prevents new users from opening the device. Already posted
761  * blocking reads will stay, however new ones will fail.
762  */
763 static void evdev_mark_dead(struct evdev *evdev)
764 {
765         mutex_lock(&evdev->mutex);
766         evdev->exist = 0;
767         mutex_unlock(&evdev->mutex);
768 }
769
770 static void evdev_cleanup(struct evdev *evdev)
771 {
772         struct input_handle *handle = &evdev->handle;
773
774         evdev_mark_dead(evdev);
775         evdev_hangup(evdev);
776         evdev_remove_chrdev(evdev);
777
778         /* evdev is marked dead so no one else accesses evdev->open */
779         if (evdev->open) {
780                 input_flush_device(handle, NULL);
781                 input_close_device(handle);
782         }
783 }
784
785 /*
786  * Create new evdev device. Note that input core serializes calls
787  * to connect and disconnect so we don't need to lock evdev_table here.
788  */
789 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
790                          const struct input_device_id *id)
791 {
792         struct evdev *evdev;
793         int minor;
794         int error;
795
796         for (minor = 0; minor < EVDEV_MINORS; minor++)
797                 if (!evdev_table[minor])
798                         break;
799
800         if (minor == EVDEV_MINORS) {
801                 printk(KERN_ERR "evdev: no more free evdev devices\n");
802                 return -ENFILE;
803         }
804
805         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
806         if (!evdev)
807                 return -ENOMEM;
808
809         INIT_LIST_HEAD(&evdev->client_list);
810         spin_lock_init(&evdev->client_lock);
811         mutex_init(&evdev->mutex);
812         init_waitqueue_head(&evdev->wait);
813
814         snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
815         evdev->exist = 1;
816         evdev->minor = minor;
817
818         evdev->handle.dev = input_get_device(dev);
819         evdev->handle.name = evdev->name;
820         evdev->handle.handler = handler;
821         evdev->handle.private = evdev;
822
823         dev_set_name(&evdev->dev, evdev->name);
824         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
825         evdev->dev.class = &input_class;
826         evdev->dev.parent = &dev->dev;
827         evdev->dev.release = evdev_free;
828         device_initialize(&evdev->dev);
829
830         error = input_register_handle(&evdev->handle);
831         if (error)
832                 goto err_free_evdev;
833
834         error = evdev_install_chrdev(evdev);
835         if (error)
836                 goto err_unregister_handle;
837
838         error = device_add(&evdev->dev);
839         if (error)
840                 goto err_cleanup_evdev;
841
842         return 0;
843
844  err_cleanup_evdev:
845         evdev_cleanup(evdev);
846  err_unregister_handle:
847         input_unregister_handle(&evdev->handle);
848  err_free_evdev:
849         put_device(&evdev->dev);
850         return error;
851 }
852
853 static void evdev_disconnect(struct input_handle *handle)
854 {
855         struct evdev *evdev = handle->private;
856
857         device_del(&evdev->dev);
858         evdev_cleanup(evdev);
859         input_unregister_handle(handle);
860         put_device(&evdev->dev);
861 }
862
863 static const struct input_device_id evdev_ids[] = {
864         { .driver_info = 1 },   /* Matches all devices */
865         { },                    /* Terminating zero entry */
866 };
867
868 MODULE_DEVICE_TABLE(input, evdev_ids);
869
870 static struct input_handler evdev_handler = {
871         .event          = evdev_event,
872         .connect        = evdev_connect,
873         .disconnect     = evdev_disconnect,
874         .fops           = &evdev_fops,
875         .minor          = EVDEV_MINOR_BASE,
876         .name           = "evdev",
877         .id_table       = evdev_ids,
878 };
879
880 static int __init evdev_init(void)
881 {
882         return input_register_handler(&evdev_handler);
883 }
884
885 static void __exit evdev_exit(void)
886 {
887         input_unregister_handler(&evdev_handler);
888 }
889
890 module_init(evdev_init);
891 module_exit(evdev_exit);
892
893 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
894 MODULE_DESCRIPTION("Input driver event char devices");
895 MODULE_LICENSE("GPL");