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