SH: remove superfluous warning from the serial driver
[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         nonseekable_open(inode, file);
282
283         return 0;
284
285  err_free_client:
286         evdev_detach_client(evdev, client);
287         kfree(client);
288  err_put_evdev:
289         put_device(&evdev->dev);
290         return error;
291 }
292
293 static ssize_t evdev_write(struct file *file, const char __user *buffer,
294                            size_t count, loff_t *ppos)
295 {
296         struct evdev_client *client = file->private_data;
297         struct evdev *evdev = client->evdev;
298         struct input_event event;
299         int retval;
300
301         retval = mutex_lock_interruptible(&evdev->mutex);
302         if (retval)
303                 return retval;
304
305         if (!evdev->exist) {
306                 retval = -ENODEV;
307                 goto out;
308         }
309
310         while (retval < count) {
311
312                 if (input_event_from_user(buffer + retval, &event)) {
313                         retval = -EFAULT;
314                         goto out;
315                 }
316
317                 input_inject_event(&evdev->handle,
318                                    event.type, event.code, event.value);
319                 retval += input_event_size();
320         }
321
322  out:
323         mutex_unlock(&evdev->mutex);
324         return retval;
325 }
326
327 static int evdev_fetch_next_event(struct evdev_client *client,
328                                   struct input_event *event)
329 {
330         int have_event;
331
332         spin_lock_irq(&client->buffer_lock);
333
334         have_event = client->head != client->tail;
335         if (have_event) {
336                 *event = client->buffer[client->tail++];
337                 client->tail &= EVDEV_BUFFER_SIZE - 1;
338         }
339
340         spin_unlock_irq(&client->buffer_lock);
341
342         return have_event;
343 }
344
345 static ssize_t evdev_read(struct file *file, char __user *buffer,
346                           size_t count, loff_t *ppos)
347 {
348         struct evdev_client *client = file->private_data;
349         struct evdev *evdev = client->evdev;
350         struct input_event event;
351         int retval;
352
353         if (count < input_event_size())
354                 return -EINVAL;
355
356         if (client->head == client->tail && evdev->exist &&
357             (file->f_flags & O_NONBLOCK))
358                 return -EAGAIN;
359
360         retval = wait_event_interruptible(evdev->wait,
361                 client->head != client->tail || !evdev->exist);
362         if (retval)
363                 return retval;
364
365         if (!evdev->exist)
366                 return -ENODEV;
367
368         while (retval + input_event_size() <= count &&
369                evdev_fetch_next_event(client, &event)) {
370
371                 if (input_event_to_user(buffer + retval, &event))
372                         return -EFAULT;
373
374                 retval += input_event_size();
375         }
376
377         return retval;
378 }
379
380 /* No kernel lock - fine */
381 static unsigned int evdev_poll(struct file *file, poll_table *wait)
382 {
383         struct evdev_client *client = file->private_data;
384         struct evdev *evdev = client->evdev;
385
386         poll_wait(file, &evdev->wait, wait);
387         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
388                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
389 }
390
391 #ifdef CONFIG_COMPAT
392
393 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
394 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
395
396 #ifdef __BIG_ENDIAN
397 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
398                         unsigned int maxlen, void __user *p, int compat)
399 {
400         int len, i;
401
402         if (compat) {
403                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
404                 if (len > maxlen)
405                         len = maxlen;
406
407                 for (i = 0; i < len / sizeof(compat_long_t); i++)
408                         if (copy_to_user((compat_long_t __user *) p + i,
409                                          (compat_long_t *) bits +
410                                                 i + 1 - ((i % 2) << 1),
411                                          sizeof(compat_long_t)))
412                                 return -EFAULT;
413         } else {
414                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
415                 if (len > maxlen)
416                         len = maxlen;
417
418                 if (copy_to_user(p, bits, len))
419                         return -EFAULT;
420         }
421
422         return len;
423 }
424 #else
425 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
426                         unsigned int maxlen, void __user *p, int compat)
427 {
428         int len = compat ?
429                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
430                         BITS_TO_LONGS(maxbit) * sizeof(long);
431
432         if (len > maxlen)
433                 len = maxlen;
434
435         return copy_to_user(p, bits, len) ? -EFAULT : len;
436 }
437 #endif /* __BIG_ENDIAN */
438
439 #else
440
441 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
442                         unsigned int maxlen, void __user *p, int compat)
443 {
444         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
445
446         if (len > maxlen)
447                 len = maxlen;
448
449         return copy_to_user(p, bits, len) ? -EFAULT : len;
450 }
451
452 #endif /* CONFIG_COMPAT */
453
454 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
455 {
456         int len;
457
458         if (!str)
459                 return -ENOENT;
460
461         len = strlen(str) + 1;
462         if (len > maxlen)
463                 len = maxlen;
464
465         return copy_to_user(p, str, len) ? -EFAULT : len;
466 }
467
468 #define OLD_KEY_MAX     0x1ff
469 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
470 {
471         static unsigned long keymax_warn_time;
472         unsigned long *bits;
473         int len;
474
475         switch (_IOC_NR(cmd) & EV_MAX) {
476
477         case      0: bits = dev->evbit;  len = EV_MAX;  break;
478         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
479         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
480         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
481         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
482         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
483         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
484         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
485         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
486         default: return -EINVAL;
487         }
488
489         /*
490          * Work around bugs in userspace programs that like to do
491          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
492          * should be in bytes, not in bits.
493          */
494         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
495                 len = OLD_KEY_MAX;
496                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
497                         printk(KERN_WARNING
498                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
499                                 "limiting output to %zu bytes. See "
500                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
501                                 OLD_KEY_MAX,
502                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
503         }
504
505         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
506 }
507 #undef OLD_KEY_MAX
508
509 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
510                            void __user *p, int compat_mode)
511 {
512         struct evdev_client *client = file->private_data;
513         struct evdev *evdev = client->evdev;
514         struct input_dev *dev = evdev->handle.dev;
515         struct input_absinfo abs;
516         struct ff_effect effect;
517         int __user *ip = (int __user *)p;
518         unsigned int i, t, u, v;
519         int error;
520
521         switch (cmd) {
522
523         case EVIOCGVERSION:
524                 return put_user(EV_VERSION, ip);
525
526         case EVIOCGID:
527                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
528                         return -EFAULT;
529                 return 0;
530
531         case EVIOCGREP:
532                 if (!test_bit(EV_REP, dev->evbit))
533                         return -ENOSYS;
534                 if (put_user(dev->rep[REP_DELAY], ip))
535                         return -EFAULT;
536                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
537                         return -EFAULT;
538                 return 0;
539
540         case EVIOCSREP:
541                 if (!test_bit(EV_REP, dev->evbit))
542                         return -ENOSYS;
543                 if (get_user(u, ip))
544                         return -EFAULT;
545                 if (get_user(v, ip + 1))
546                         return -EFAULT;
547
548                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
549                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
550
551                 return 0;
552
553         case EVIOCGKEYCODE:
554                 if (get_user(t, ip))
555                         return -EFAULT;
556
557                 error = input_get_keycode(dev, t, &v);
558                 if (error)
559                         return error;
560
561                 if (put_user(v, ip + 1))
562                         return -EFAULT;
563
564                 return 0;
565
566         case EVIOCSKEYCODE:
567                 if (get_user(t, ip) || get_user(v, ip + 1))
568                         return -EFAULT;
569
570                 return input_set_keycode(dev, t, v);
571
572         case EVIOCRMFF:
573                 return input_ff_erase(dev, (int)(unsigned long) p, file);
574
575         case EVIOCGEFFECTS:
576                 i = test_bit(EV_FF, dev->evbit) ?
577                                 dev->ff->max_effects : 0;
578                 if (put_user(i, ip))
579                         return -EFAULT;
580                 return 0;
581
582         case EVIOCGRAB:
583                 if (p)
584                         return evdev_grab(evdev, client);
585                 else
586                         return evdev_ungrab(evdev, client);
587
588         default:
589
590                 if (_IOC_TYPE(cmd) != 'E')
591                         return -EINVAL;
592
593                 if (_IOC_DIR(cmd) == _IOC_READ) {
594
595                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
596                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
597
598                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
599                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
600                                                     p, compat_mode);
601
602                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
603                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
604                                                     p, compat_mode);
605
606                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
607                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
608                                                     p, compat_mode);
609
610                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
611                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
612                                                     p, compat_mode);
613
614                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
615                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
616
617                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
618                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
619
620                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
621                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
622
623                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
624
625                                 t = _IOC_NR(cmd) & ABS_MAX;
626
627                                 abs.value = dev->abs[t];
628                                 abs.minimum = dev->absmin[t];
629                                 abs.maximum = dev->absmax[t];
630                                 abs.fuzz = dev->absfuzz[t];
631                                 abs.flat = dev->absflat[t];
632                                 abs.resolution = dev->absres[t];
633
634                                 if (copy_to_user(p, &abs, min_t(size_t,
635                                                                 _IOC_SIZE(cmd),
636                                                                 sizeof(struct input_absinfo))))
637                                         return -EFAULT;
638
639                                 return 0;
640                         }
641
642                 }
643
644                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
645
646                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
647
648                                 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
649                                         return -EFAULT;
650
651                                 error = input_ff_upload(dev, &effect, file);
652
653                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
654                                         return -EFAULT;
655
656                                 return error;
657                         }
658
659                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
660
661                                 t = _IOC_NR(cmd) & ABS_MAX;
662
663                                 if (copy_from_user(&abs, p, min_t(size_t,
664                                                                   _IOC_SIZE(cmd),
665                                                                   sizeof(struct input_absinfo))))
666                                         return -EFAULT;
667
668                                 /*
669                                  * Take event lock to ensure that we are not
670                                  * changing device parameters in the middle
671                                  * of event.
672                                  */
673                                 spin_lock_irq(&dev->event_lock);
674
675                                 dev->abs[t] = abs.value;
676                                 dev->absmin[t] = abs.minimum;
677                                 dev->absmax[t] = abs.maximum;
678                                 dev->absfuzz[t] = abs.fuzz;
679                                 dev->absflat[t] = abs.flat;
680                                 dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
681                                                         0 : abs.resolution;
682
683                                 spin_unlock_irq(&dev->event_lock);
684
685                                 return 0;
686                         }
687                 }
688         }
689         return -EINVAL;
690 }
691
692 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
693                                 void __user *p, int compat_mode)
694 {
695         struct evdev_client *client = file->private_data;
696         struct evdev *evdev = client->evdev;
697         int retval;
698
699         retval = mutex_lock_interruptible(&evdev->mutex);
700         if (retval)
701                 return retval;
702
703         if (!evdev->exist) {
704                 retval = -ENODEV;
705                 goto out;
706         }
707
708         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
709
710  out:
711         mutex_unlock(&evdev->mutex);
712         return retval;
713 }
714
715 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
716 {
717         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
718 }
719
720 #ifdef CONFIG_COMPAT
721 static long evdev_ioctl_compat(struct file *file,
722                                 unsigned int cmd, unsigned long arg)
723 {
724         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
725 }
726 #endif
727
728 static const struct file_operations evdev_fops = {
729         .owner          = THIS_MODULE,
730         .read           = evdev_read,
731         .write          = evdev_write,
732         .poll           = evdev_poll,
733         .open           = evdev_open,
734         .release        = evdev_release,
735         .unlocked_ioctl = evdev_ioctl,
736 #ifdef CONFIG_COMPAT
737         .compat_ioctl   = evdev_ioctl_compat,
738 #endif
739         .fasync         = evdev_fasync,
740         .flush          = evdev_flush
741 };
742
743 static int evdev_install_chrdev(struct evdev *evdev)
744 {
745         /*
746          * No need to do any locking here as calls to connect and
747          * disconnect are serialized by the input core
748          */
749         evdev_table[evdev->minor] = evdev;
750         return 0;
751 }
752
753 static void evdev_remove_chrdev(struct evdev *evdev)
754 {
755         /*
756          * Lock evdev table to prevent race with evdev_open()
757          */
758         mutex_lock(&evdev_table_mutex);
759         evdev_table[evdev->minor] = NULL;
760         mutex_unlock(&evdev_table_mutex);
761 }
762
763 /*
764  * Mark device non-existent. This disables writes, ioctls and
765  * prevents new users from opening the device. Already posted
766  * blocking reads will stay, however new ones will fail.
767  */
768 static void evdev_mark_dead(struct evdev *evdev)
769 {
770         mutex_lock(&evdev->mutex);
771         evdev->exist = 0;
772         mutex_unlock(&evdev->mutex);
773 }
774
775 static void evdev_cleanup(struct evdev *evdev)
776 {
777         struct input_handle *handle = &evdev->handle;
778
779         evdev_mark_dead(evdev);
780         evdev_hangup(evdev);
781         evdev_remove_chrdev(evdev);
782
783         /* evdev is marked dead so no one else accesses evdev->open */
784         if (evdev->open) {
785                 input_flush_device(handle, NULL);
786                 input_close_device(handle);
787         }
788 }
789
790 /*
791  * Create new evdev device. Note that input core serializes calls
792  * to connect and disconnect so we don't need to lock evdev_table here.
793  */
794 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
795                          const struct input_device_id *id)
796 {
797         struct evdev *evdev;
798         int minor;
799         int error;
800
801         for (minor = 0; minor < EVDEV_MINORS; minor++)
802                 if (!evdev_table[minor])
803                         break;
804
805         if (minor == EVDEV_MINORS) {
806                 printk(KERN_ERR "evdev: no more free evdev devices\n");
807                 return -ENFILE;
808         }
809
810         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
811         if (!evdev)
812                 return -ENOMEM;
813
814         INIT_LIST_HEAD(&evdev->client_list);
815         spin_lock_init(&evdev->client_lock);
816         mutex_init(&evdev->mutex);
817         init_waitqueue_head(&evdev->wait);
818
819         dev_set_name(&evdev->dev, "event%d", minor);
820         evdev->exist = 1;
821         evdev->minor = minor;
822
823         evdev->handle.dev = input_get_device(dev);
824         evdev->handle.name = dev_name(&evdev->dev);
825         evdev->handle.handler = handler;
826         evdev->handle.private = evdev;
827
828         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
829         evdev->dev.class = &input_class;
830         evdev->dev.parent = &dev->dev;
831         evdev->dev.release = evdev_free;
832         device_initialize(&evdev->dev);
833
834         error = input_register_handle(&evdev->handle);
835         if (error)
836                 goto err_free_evdev;
837
838         error = evdev_install_chrdev(evdev);
839         if (error)
840                 goto err_unregister_handle;
841
842         error = device_add(&evdev->dev);
843         if (error)
844                 goto err_cleanup_evdev;
845
846         return 0;
847
848  err_cleanup_evdev:
849         evdev_cleanup(evdev);
850  err_unregister_handle:
851         input_unregister_handle(&evdev->handle);
852  err_free_evdev:
853         put_device(&evdev->dev);
854         return error;
855 }
856
857 static void evdev_disconnect(struct input_handle *handle)
858 {
859         struct evdev *evdev = handle->private;
860
861         device_del(&evdev->dev);
862         evdev_cleanup(evdev);
863         input_unregister_handle(handle);
864         put_device(&evdev->dev);
865 }
866
867 static const struct input_device_id evdev_ids[] = {
868         { .driver_info = 1 },   /* Matches all devices */
869         { },                    /* Terminating zero entry */
870 };
871
872 MODULE_DEVICE_TABLE(input, evdev_ids);
873
874 static struct input_handler evdev_handler = {
875         .event          = evdev_event,
876         .connect        = evdev_connect,
877         .disconnect     = evdev_disconnect,
878         .fops           = &evdev_fops,
879         .minor          = EVDEV_MINOR_BASE,
880         .name           = "evdev",
881         .id_table       = evdev_ids,
882 };
883
884 static int __init evdev_init(void)
885 {
886         return input_register_handler(&evdev_handler);
887 }
888
889 static void __exit evdev_exit(void)
890 {
891         input_unregister_handler(&evdev_handler);
892 }
893
894 module_init(evdev_init);
895 module_exit(evdev_exit);
896
897 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
898 MODULE_DESCRIPTION("Input driver event char devices");
899 MODULE_LICENSE("GPL");