projects/linux·blob v2.6.25 · refs

974 lines · 21.6 KiB

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 <linux/compat.h>
23
24struct 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
38struct 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
48static struct evdev *evdev_table[EVDEV_MINORS];
49static DEFINE_MUTEX(evdev_table_mutex);
50
51static 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 */
68static 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
94static 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
104static 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
123static 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 */
135static 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
152static 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
164static 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
173static 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
182static 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
202static 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 */
216static 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
228static 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
248static 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#ifdef CONFIG_COMPAT
295
296struct input_event_compat {
297 struct compat_timeval time;
298 __u16 type;
299 __u16 code;
300 __s32 value;
301};
302
303/* Note to the author of this code: did it ever occur to
304 you why the ifdefs are needed? Think about it again. -AK */
305#ifdef CONFIG_X86_64
306# define COMPAT_TEST is_compat_task()
307#elif defined(CONFIG_IA64)
308# define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current))
309#elif defined(CONFIG_S390)
310# define COMPAT_TEST test_thread_flag(TIF_31BIT)
311#elif defined(CONFIG_MIPS)
312# define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
313#else
314# define COMPAT_TEST test_thread_flag(TIF_32BIT)
315#endif
316
317static inline size_t evdev_event_size(void)
318{
319 return COMPAT_TEST ?
320 sizeof(struct input_event_compat) : sizeof(struct input_event);
321}
322
323static int evdev_event_from_user(const char __user *buffer,
324 struct input_event *event)
325{
326 if (COMPAT_TEST) {
327 struct input_event_compat compat_event;
328
329 if (copy_from_user(&compat_event, buffer,
330 sizeof(struct input_event_compat)))
331 return -EFAULT;
332
333 event->time.tv_sec = compat_event.time.tv_sec;
334 event->time.tv_usec = compat_event.time.tv_usec;
335 event->type = compat_event.type;
336 event->code = compat_event.code;
337 event->value = compat_event.value;
338
339 } else {
340 if (copy_from_user(event, buffer, sizeof(struct input_event)))
341 return -EFAULT;
342 }
343
344 return 0;
345}
346
347static int evdev_event_to_user(char __user *buffer,
348 const struct input_event *event)
349{
350 if (COMPAT_TEST) {
351 struct input_event_compat compat_event;
352
353 compat_event.time.tv_sec = event->time.tv_sec;
354 compat_event.time.tv_usec = event->time.tv_usec;
355 compat_event.type = event->type;
356 compat_event.code = event->code;
357 compat_event.value = event->value;
358
359 if (copy_to_user(buffer, &compat_event,
360 sizeof(struct input_event_compat)))
361 return -EFAULT;
362
363 } else {
364 if (copy_to_user(buffer, event, sizeof(struct input_event)))
365 return -EFAULT;
366 }
367
368 return 0;
369}
370
371#else
372
373static inline size_t evdev_event_size(void)
374{
375 return sizeof(struct input_event);
376}
377
378static int evdev_event_from_user(const char __user *buffer,
379 struct input_event *event)
380{
381 if (copy_from_user(event, buffer, sizeof(struct input_event)))
382 return -EFAULT;
383
384 return 0;
385}
386
387static int evdev_event_to_user(char __user *buffer,
388 const struct input_event *event)
389{
390 if (copy_to_user(buffer, event, sizeof(struct input_event)))
391 return -EFAULT;
392
393 return 0;
394}
395
396#endif /* CONFIG_COMPAT */
397
398static ssize_t evdev_write(struct file *file, const char __user *buffer,
399 size_t count, loff_t *ppos)
400{
401 struct evdev_client *client = file->private_data;
402 struct evdev *evdev = client->evdev;
403 struct input_event event;
404 int retval;
405
406 retval = mutex_lock_interruptible(&evdev->mutex);
407 if (retval)
408 return retval;
409
410 if (!evdev->exist) {
411 retval = -ENODEV;
412 goto out;
413 }
414
415 while (retval < count) {
416
417 if (evdev_event_from_user(buffer + retval, &event)) {
418 retval = -EFAULT;
419 goto out;
420 }
421
422 input_inject_event(&evdev->handle,
423 event.type, event.code, event.value);
424 retval += evdev_event_size();
425 }
426
427 out:
428 mutex_unlock(&evdev->mutex);
429 return retval;
430}
431
432static int evdev_fetch_next_event(struct evdev_client *client,
433 struct input_event *event)
434{
435 int have_event;
436
437 spin_lock_irq(&client->buffer_lock);
438
439 have_event = client->head != client->tail;
440 if (have_event) {
441 *event = client->buffer[client->tail++];
442 client->tail &= EVDEV_BUFFER_SIZE - 1;
443 }
444
445 spin_unlock_irq(&client->buffer_lock);
446
447 return have_event;
448}
449
450static ssize_t evdev_read(struct file *file, char __user *buffer,
451 size_t count, loff_t *ppos)
452{
453 struct evdev_client *client = file->private_data;
454 struct evdev *evdev = client->evdev;
455 struct input_event event;
456 int retval;
457
458 if (count < evdev_event_size())
459 return -EINVAL;
460
461 if (client->head == client->tail && evdev->exist &&
462 (file->f_flags & O_NONBLOCK))
463 return -EAGAIN;
464
465 retval = wait_event_interruptible(evdev->wait,
466 client->head != client->tail || !evdev->exist);
467 if (retval)
468 return retval;
469
470 if (!evdev->exist)
471 return -ENODEV;
472
473 while (retval + evdev_event_size() <= count &&
474 evdev_fetch_next_event(client, &event)) {
475
476 if (evdev_event_to_user(buffer + retval, &event))
477 return -EFAULT;
478
479 retval += evdev_event_size();
480 }
481
482 return retval;
483}
484
485/* No kernel lock - fine */
486static unsigned int evdev_poll(struct file *file, poll_table *wait)
487{
488 struct evdev_client *client = file->private_data;
489 struct evdev *evdev = client->evdev;
490
491 poll_wait(file, &evdev->wait, wait);
492 return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
493 (evdev->exist ? 0 : (POLLHUP | POLLERR));
494}
495
496#ifdef CONFIG_COMPAT
497
498#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
499#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
500
501#ifdef __BIG_ENDIAN
502static int bits_to_user(unsigned long *bits, unsigned int maxbit,
503 unsigned int maxlen, void __user *p, int compat)
504{
505 int len, i;
506
507 if (compat) {
508 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
509 if (len > maxlen)
510 len = maxlen;
511
512 for (i = 0; i < len / sizeof(compat_long_t); i++)
513 if (copy_to_user((compat_long_t __user *) p + i,
514 (compat_long_t *) bits +
515 i + 1 - ((i % 2) << 1),
516 sizeof(compat_long_t)))
517 return -EFAULT;
518 } else {
519 len = BITS_TO_LONGS(maxbit) * sizeof(long);
520 if (len > maxlen)
521 len = maxlen;
522
523 if (copy_to_user(p, bits, len))
524 return -EFAULT;
525 }
526
527 return len;
528}
529#else
530static int bits_to_user(unsigned long *bits, unsigned int maxbit,
531 unsigned int maxlen, void __user *p, int compat)
532{
533 int len = compat ?
534 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
535 BITS_TO_LONGS(maxbit) * sizeof(long);
536
537 if (len > maxlen)
538 len = maxlen;
539
540 return copy_to_user(p, bits, len) ? -EFAULT : len;
541}
542#endif /* __BIG_ENDIAN */
543
544#else
545
546static int bits_to_user(unsigned long *bits, unsigned int maxbit,
547 unsigned int maxlen, void __user *p, int compat)
548{
549 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
550
551 if (len > maxlen)
552 len = maxlen;
553
554 return copy_to_user(p, bits, len) ? -EFAULT : len;
555}
556
557#endif /* CONFIG_COMPAT */
558
559static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
560{
561 int len;
562
563 if (!str)
564 return -ENOENT;
565
566 len = strlen(str) + 1;
567 if (len > maxlen)
568 len = maxlen;
569
570 return copy_to_user(p, str, len) ? -EFAULT : len;
571}
572
573static long evdev_do_ioctl(struct file *file, unsigned int cmd,
574 void __user *p, int compat_mode)
575{
576 struct evdev_client *client = file->private_data;
577 struct evdev *evdev = client->evdev;
578 struct input_dev *dev = evdev->handle.dev;
579 struct input_absinfo abs;
580 struct ff_effect effect;
581 int __user *ip = (int __user *)p;
582 int i, t, u, v;
583 int error;
584
585 switch (cmd) {
586
587 case EVIOCGVERSION:
588 return put_user(EV_VERSION, ip);
589
590 case EVIOCGID:
591 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
592 return -EFAULT;
593 return 0;
594
595 case EVIOCGREP:
596 if (!test_bit(EV_REP, dev->evbit))
597 return -ENOSYS;
598 if (put_user(dev->rep[REP_DELAY], ip))
599 return -EFAULT;
600 if (put_user(dev->rep[REP_PERIOD], ip + 1))
601 return -EFAULT;
602 return 0;
603
604 case EVIOCSREP:
605 if (!test_bit(EV_REP, dev->evbit))
606 return -ENOSYS;
607 if (get_user(u, ip))
608 return -EFAULT;
609 if (get_user(v, ip + 1))
610 return -EFAULT;
611
612 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
613 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
614
615 return 0;
616
617 case EVIOCGKEYCODE:
618 if (get_user(t, ip))
619 return -EFAULT;
620
621 error = input_get_keycode(dev, t, &v);
622 if (error)
623 return error;
624
625 if (put_user(v, ip + 1))
626 return -EFAULT;
627
628 return 0;
629
630 case EVIOCSKEYCODE:
631 if (get_user(t, ip) || get_user(v, ip + 1))
632 return -EFAULT;
633
634 return input_set_keycode(dev, t, v);
635
636 case EVIOCSFF:
637 if (copy_from_user(&effect, p, sizeof(effect)))
638 return -EFAULT;
639
640 error = input_ff_upload(dev, &effect, file);
641
642 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
643 return -EFAULT;
644
645 return error;
646
647 case EVIOCRMFF:
648 return input_ff_erase(dev, (int)(unsigned long) p, file);
649
650 case EVIOCGEFFECTS:
651 i = test_bit(EV_FF, dev->evbit) ?
652 dev->ff->max_effects : 0;
653 if (put_user(i, ip))
654 return -EFAULT;
655 return 0;
656
657 case EVIOCGRAB:
658 if (p)
659 return evdev_grab(evdev, client);
660 else
661 return evdev_ungrab(evdev, client);
662
663 default:
664
665 if (_IOC_TYPE(cmd) != 'E')
666 return -EINVAL;
667
668 if (_IOC_DIR(cmd) == _IOC_READ) {
669
670 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) {
671
672 unsigned long *bits;
673 int len;
674
675 switch (_IOC_NR(cmd) & EV_MAX) {
676
677 case 0: bits = dev->evbit; len = EV_MAX; break;
678 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
679 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
680 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
681 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
682 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
683 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
684 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
685 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
686 default: return -EINVAL;
687 }
688 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
689 }
690
691 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
692 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
693 p, compat_mode);
694
695 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
696 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
697 p, compat_mode);
698
699 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
700 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
701 p, compat_mode);
702
703 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
704 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
705 p, compat_mode);
706
707 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
708 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
709
710 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
711 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
712
713 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
714 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
715
716 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
717
718 t = _IOC_NR(cmd) & ABS_MAX;
719
720 abs.value = dev->abs[t];
721 abs.minimum = dev->absmin[t];
722 abs.maximum = dev->absmax[t];
723 abs.fuzz = dev->absfuzz[t];
724 abs.flat = dev->absflat[t];
725
726 if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
727 return -EFAULT;
728
729 return 0;
730 }
731
732 }
733
734 if (_IOC_DIR(cmd) == _IOC_WRITE) {
735
736 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
737
738 t = _IOC_NR(cmd) & ABS_MAX;
739
740 if (copy_from_user(&abs, p,
741 sizeof(struct input_absinfo)))
742 return -EFAULT;
743
744 /*
745 * Take event lock to ensure that we are not
746 * changing device parameters in the middle
747 * of event.
748 */
749 spin_lock_irq(&dev->event_lock);
750
751 dev->abs[t] = abs.value;
752 dev->absmin[t] = abs.minimum;
753 dev->absmax[t] = abs.maximum;
754 dev->absfuzz[t] = abs.fuzz;
755 dev->absflat[t] = abs.flat;
756
757 spin_unlock_irq(&dev->event_lock);
758
759 return 0;
760 }
761 }
762 }
763 return -EINVAL;
764}
765
766static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
767 void __user *p, int compat_mode)
768{
769 struct evdev_client *client = file->private_data;
770 struct evdev *evdev = client->evdev;
771 int retval;
772
773 retval = mutex_lock_interruptible(&evdev->mutex);
774 if (retval)
775 return retval;
776
777 if (!evdev->exist) {
778 retval = -ENODEV;
779 goto out;
780 }
781
782 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
783
784 out:
785 mutex_unlock(&evdev->mutex);
786 return retval;
787}
788
789static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
790{
791 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
792}
793
794#ifdef CONFIG_COMPAT
795static long evdev_ioctl_compat(struct file *file,
796 unsigned int cmd, unsigned long arg)
797{
798 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
799}
800#endif
801
802static const struct file_operations evdev_fops = {
803 .owner = THIS_MODULE,
804 .read = evdev_read,
805 .write = evdev_write,
806 .poll = evdev_poll,
807 .open = evdev_open,
808 .release = evdev_release,
809 .unlocked_ioctl = evdev_ioctl,
810#ifdef CONFIG_COMPAT
811 .compat_ioctl = evdev_ioctl_compat,
812#endif
813 .fasync = evdev_fasync,
814 .flush = evdev_flush
815};
816
817static int evdev_install_chrdev(struct evdev *evdev)
818{
819 /*
820 * No need to do any locking here as calls to connect and
821 * disconnect are serialized by the input core
822 */
823 evdev_table[evdev->minor] = evdev;
824 return 0;
825}
826
827static void evdev_remove_chrdev(struct evdev *evdev)
828{
829 /*
830 * Lock evdev table to prevent race with evdev_open()
831 */
832 mutex_lock(&evdev_table_mutex);
833 evdev_table[evdev->minor] = NULL;
834 mutex_unlock(&evdev_table_mutex);
835}
836
837/*
838 * Mark device non-existent. This disables writes, ioctls and
839 * prevents new users from opening the device. Already posted
840 * blocking reads will stay, however new ones will fail.
841 */
842static void evdev_mark_dead(struct evdev *evdev)
843{
844 mutex_lock(&evdev->mutex);
845 evdev->exist = 0;
846 mutex_unlock(&evdev->mutex);
847}
848
849static void evdev_cleanup(struct evdev *evdev)
850{
851 struct input_handle *handle = &evdev->handle;
852
853 evdev_mark_dead(evdev);
854 evdev_hangup(evdev);
855 evdev_remove_chrdev(evdev);
856
857 /* evdev is marked dead so no one else accesses evdev->open */
858 if (evdev->open) {
859 input_flush_device(handle, NULL);
860 input_close_device(handle);
861 }
862}
863
864/*
865 * Create new evdev device. Note that input core serializes calls
866 * to connect and disconnect so we don't need to lock evdev_table here.
867 */
868static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
869 const struct input_device_id *id)
870{
871 struct evdev *evdev;
872 int minor;
873 int error;
874
875 for (minor = 0; minor < EVDEV_MINORS; minor++)
876 if (!evdev_table[minor])
877 break;
878
879 if (minor == EVDEV_MINORS) {
880 printk(KERN_ERR "evdev: no more free evdev devices\n");
881 return -ENFILE;
882 }
883
884 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
885 if (!evdev)
886 return -ENOMEM;
887
888 INIT_LIST_HEAD(&evdev->client_list);
889 spin_lock_init(&evdev->client_lock);
890 mutex_init(&evdev->mutex);
891 init_waitqueue_head(&evdev->wait);
892
893 snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
894 evdev->exist = 1;
895 evdev->minor = minor;
896
897 evdev->handle.dev = input_get_device(dev);
898 evdev->handle.name = evdev->name;
899 evdev->handle.handler = handler;
900 evdev->handle.private = evdev;
901
902 strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id));
903 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
904 evdev->dev.class = &input_class;
905 evdev->dev.parent = &dev->dev;
906 evdev->dev.release = evdev_free;
907 device_initialize(&evdev->dev);
908
909 error = input_register_handle(&evdev->handle);
910 if (error)
911 goto err_free_evdev;
912
913 error = evdev_install_chrdev(evdev);
914 if (error)
915 goto err_unregister_handle;
916
917 error = device_add(&evdev->dev);
918 if (error)
919 goto err_cleanup_evdev;
920
921 return 0;
922
923 err_cleanup_evdev:
924 evdev_cleanup(evdev);
925 err_unregister_handle:
926 input_unregister_handle(&evdev->handle);
927 err_free_evdev:
928 put_device(&evdev->dev);
929 return error;
930}
931
932static void evdev_disconnect(struct input_handle *handle)
933{
934 struct evdev *evdev = handle->private;
935
936 device_del(&evdev->dev);
937 evdev_cleanup(evdev);
938 input_unregister_handle(handle);
939 put_device(&evdev->dev);
940}
941
942static const struct input_device_id evdev_ids[] = {
943 { .driver_info = 1 }, /* Matches all devices */
944 { }, /* Terminating zero entry */
945};
946
947MODULE_DEVICE_TABLE(input, evdev_ids);
948
949static struct input_handler evdev_handler = {
950 .event = evdev_event,
951 .connect = evdev_connect,
952 .disconnect = evdev_disconnect,
953 .fops = &evdev_fops,
954 .minor = EVDEV_MINOR_BASE,
955 .name = "evdev",
956 .id_table = evdev_ids,
957};
958
959static int __init evdev_init(void)
960{
961 return input_register_handler(&evdev_handler);
962}
963
964static void __exit evdev_exit(void)
965{
966 input_unregister_handler(&evdev_handler);
967}
968
969module_init(evdev_init);
970module_exit(evdev_exit);
971
972MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
973MODULE_DESCRIPTION("Input driver event char devices");
974MODULE_LICENSE("GPL");