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Input: add ROHM BU21013 touch panel controller support
[linux-2.6/kvm.git] / drivers / input / evdev.c
blob1ce9bf6632066db36366e15b4b2b43c83acc3134
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_MIN_BUFFER_SIZE 64U
14 #define EVDEV_BUF_PACKETS 8
15
16 #include <linux/poll.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/input.h>
22 #include <linux/major.h>
23 #include <linux/device.h>
24 #include "input-compat.h"
25
26 struct evdev {
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 bool exist;
37 };
38
39 struct evdev_client {
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 int bufsize;
47 struct input_event buffer[];
48 };
49
50 static struct evdev *evdev_table[EVDEV_MINORS];
51 static DEFINE_MUTEX(evdev_table_mutex);
52
53 static void evdev_pass_event(struct evdev_client *client,
54 struct input_event *event)
55 {
56 /*
57 * Interrupts are disabled, just acquire the lock.
58 * Make sure we don't leave with the client buffer
59 * "empty" by having client->head == client->tail.
60 */
61 spin_lock(&client->buffer_lock);
62 do {
63 client->buffer[client->head++] = *event;
64 client->head &= client->bufsize - 1;
65 } while (client->head == client->tail);
66 spin_unlock(&client->buffer_lock);
67
68 if (event->type == EV_SYN)
69 kill_fasync(&client->fasync, SIGIO, POLL_IN);
70 }
71
72 /*
73 * Pass incoming event to all connected clients.
74 */
75 static void evdev_event(struct input_handle *handle,
76 unsigned int type, unsigned int code, int value)
77 {
78 struct evdev *evdev = handle->private;
79 struct evdev_client *client;
80 struct input_event event;
81
82 do_gettimeofday(&event.time);
83 event.type = type;
84 event.code = code;
85 event.value = value;
86
87 rcu_read_lock();
88
89 client = rcu_dereference(evdev->grab);
90 if (client)
91 evdev_pass_event(client, &event);
92 else
93 list_for_each_entry_rcu(client, &evdev->client_list, node)
94 evdev_pass_event(client, &event);
95
96 rcu_read_unlock();
97
98 wake_up_interruptible(&evdev->wait);
99 }
100
101 static int evdev_fasync(int fd, struct file *file, int on)
102 {
103 struct evdev_client *client = file->private_data;
104
105 return fasync_helper(fd, file, on, &client->fasync);
106 }
107
108 static int evdev_flush(struct file *file, fl_owner_t id)
109 {
110 struct evdev_client *client = file->private_data;
111 struct evdev *evdev = client->evdev;
112 int retval;
113
114 retval = mutex_lock_interruptible(&evdev->mutex);
115 if (retval)
116 return retval;
117
118 if (!evdev->exist)
119 retval = -ENODEV;
120 else
121 retval = input_flush_device(&evdev->handle, file);
122
123 mutex_unlock(&evdev->mutex);
124 return retval;
125 }
126
127 static void evdev_free(struct device *dev)
128 {
129 struct evdev *evdev = container_of(dev, struct evdev, dev);
130
131 input_put_device(evdev->handle.dev);
132 kfree(evdev);
133 }
134
135 /*
136 * Grabs an event device (along with underlying input device).
137 * This function is called with evdev->mutex taken.
138 */
139 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
140 {
141 int error;
142
143 if (evdev->grab)
144 return -EBUSY;
145
146 error = input_grab_device(&evdev->handle);
147 if (error)
148 return error;
149
150 rcu_assign_pointer(evdev->grab, client);
151 synchronize_rcu();
152
153 return 0;
154 }
155
156 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
157 {
158 if (evdev->grab != client)
159 return -EINVAL;
160
161 rcu_assign_pointer(evdev->grab, NULL);
162 synchronize_rcu();
163 input_release_device(&evdev->handle);
164
165 return 0;
166 }
167
168 static void evdev_attach_client(struct evdev *evdev,
169 struct evdev_client *client)
170 {
171 spin_lock(&evdev->client_lock);
172 list_add_tail_rcu(&client->node, &evdev->client_list);
173 spin_unlock(&evdev->client_lock);
174 synchronize_rcu();
175 }
176
177 static void evdev_detach_client(struct evdev *evdev,
178 struct evdev_client *client)
179 {
180 spin_lock(&evdev->client_lock);
181 list_del_rcu(&client->node);
182 spin_unlock(&evdev->client_lock);
183 synchronize_rcu();
184 }
185
186 static int evdev_open_device(struct evdev *evdev)
187 {
188 int retval;
189
190 retval = mutex_lock_interruptible(&evdev->mutex);
191 if (retval)
192 return retval;
193
194 if (!evdev->exist)
195 retval = -ENODEV;
196 else if (!evdev->open++) {
197 retval = input_open_device(&evdev->handle);
198 if (retval)
199 evdev->open--;
200 }
201
202 mutex_unlock(&evdev->mutex);
203 return retval;
204 }
205
206 static void evdev_close_device(struct evdev *evdev)
207 {
208 mutex_lock(&evdev->mutex);
209
210 if (evdev->exist && !--evdev->open)
211 input_close_device(&evdev->handle);
212
213 mutex_unlock(&evdev->mutex);
214 }
215
216 /*
217 * Wake up users waiting for IO so they can disconnect from
218 * dead device.
219 */
220 static void evdev_hangup(struct evdev *evdev)
221 {
222 struct evdev_client *client;
223
224 spin_lock(&evdev->client_lock);
225 list_for_each_entry(client, &evdev->client_list, node)
226 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
227 spin_unlock(&evdev->client_lock);
228
229 wake_up_interruptible(&evdev->wait);
230 }
231
232 static int evdev_release(struct inode *inode, struct file *file)
233 {
234 struct evdev_client *client = file->private_data;
235 struct evdev *evdev = client->evdev;
236
237 mutex_lock(&evdev->mutex);
238 if (evdev->grab == client)
239 evdev_ungrab(evdev, client);
240 mutex_unlock(&evdev->mutex);
241
242 evdev_detach_client(evdev, client);
243 kfree(client);
244
245 evdev_close_device(evdev);
246 put_device(&evdev->dev);
247
248 return 0;
249 }
250
251 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
252 {
253 unsigned int n_events =
254 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
255 EVDEV_MIN_BUFFER_SIZE);
256
257 return roundup_pow_of_two(n_events);
258 }
259
260 static int evdev_open(struct inode *inode, struct file *file)
261 {
262 struct evdev *evdev;
263 struct evdev_client *client;
264 int i = iminor(inode) - EVDEV_MINOR_BASE;
265 unsigned int bufsize;
266 int error;
267
268 if (i >= EVDEV_MINORS)
269 return -ENODEV;
270
271 error = mutex_lock_interruptible(&evdev_table_mutex);
272 if (error)
273 return error;
274 evdev = evdev_table[i];
275 if (evdev)
276 get_device(&evdev->dev);
277 mutex_unlock(&evdev_table_mutex);
278
279 if (!evdev)
280 return -ENODEV;
281
282 bufsize = evdev_compute_buffer_size(evdev->handle.dev);
283
284 client = kzalloc(sizeof(struct evdev_client) +
285 bufsize * sizeof(struct input_event),
286 GFP_KERNEL);
287 if (!client) {
288 error = -ENOMEM;
289 goto err_put_evdev;
290 }
291
292 client->bufsize = bufsize;
293 spin_lock_init(&client->buffer_lock);
294 client->evdev = evdev;
295 evdev_attach_client(evdev, client);
296
297 error = evdev_open_device(evdev);
298 if (error)
299 goto err_free_client;
300
301 file->private_data = client;
302 nonseekable_open(inode, file);
303
304 return 0;
305
306 err_free_client:
307 evdev_detach_client(evdev, client);
308 kfree(client);
309 err_put_evdev:
310 put_device(&evdev->dev);
311 return error;
312 }
313
314 static ssize_t evdev_write(struct file *file, const char __user *buffer,
315 size_t count, loff_t *ppos)
316 {
317 struct evdev_client *client = file->private_data;
318 struct evdev *evdev = client->evdev;
319 struct input_event event;
320 int retval;
321
322 retval = mutex_lock_interruptible(&evdev->mutex);
323 if (retval)
324 return retval;
325
326 if (!evdev->exist) {
327 retval = -ENODEV;
328 goto out;
329 }
330
331 while (retval < count) {
332
333 if (input_event_from_user(buffer + retval, &event)) {
334 retval = -EFAULT;
335 goto out;
336 }
337
338 input_inject_event(&evdev->handle,
339 event.type, event.code, event.value);
340 retval += input_event_size();
341 }
342
343 out:
344 mutex_unlock(&evdev->mutex);
345 return retval;
346 }
347
348 static int evdev_fetch_next_event(struct evdev_client *client,
349 struct input_event *event)
350 {
351 int have_event;
352
353 spin_lock_irq(&client->buffer_lock);
354
355 have_event = client->head != client->tail;
356 if (have_event) {
357 *event = client->buffer[client->tail++];
358 client->tail &= client->bufsize - 1;
359 }
360
361 spin_unlock_irq(&client->buffer_lock);
362
363 return have_event;
364 }
365
366 static ssize_t evdev_read(struct file *file, char __user *buffer,
367 size_t count, loff_t *ppos)
368 {
369 struct evdev_client *client = file->private_data;
370 struct evdev *evdev = client->evdev;
371 struct input_event event;
372 int retval;
373
374 if (count < input_event_size())
375 return -EINVAL;
376
377 if (client->head == client->tail && evdev->exist &&
378 (file->f_flags & O_NONBLOCK))
379 return -EAGAIN;
380
381 retval = wait_event_interruptible(evdev->wait,
382 client->head != client->tail || !evdev->exist);
383 if (retval)
384 return retval;
385
386 if (!evdev->exist)
387 return -ENODEV;
388
389 while (retval + input_event_size() <= count &&
390 evdev_fetch_next_event(client, &event)) {
391
392 if (input_event_to_user(buffer + retval, &event))
393 return -EFAULT;
394
395 retval += input_event_size();
396 }
397
398 return retval;
399 }
400
401 /* No kernel lock - fine */
402 static unsigned int evdev_poll(struct file *file, poll_table *wait)
403 {
404 struct evdev_client *client = file->private_data;
405 struct evdev *evdev = client->evdev;
406 unsigned int mask;
407
408 poll_wait(file, &evdev->wait, wait);
409
410 mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
411 if (client->head != client->tail)
412 mask |= POLLIN | POLLRDNORM;
413
414 return mask;
415 }
416
417 #ifdef CONFIG_COMPAT
418
419 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
420 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
421
422 #ifdef __BIG_ENDIAN
423 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
424 unsigned int maxlen, void __user *p, int compat)
425 {
426 int len, i;
427
428 if (compat) {
429 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
430 if (len > maxlen)
431 len = maxlen;
432
433 for (i = 0; i < len / sizeof(compat_long_t); i++)
434 if (copy_to_user((compat_long_t __user *) p + i,
435 (compat_long_t *) bits +
436 i + 1 - ((i % 2) << 1),
437 sizeof(compat_long_t)))
438 return -EFAULT;
439 } else {
440 len = BITS_TO_LONGS(maxbit) * sizeof(long);
441 if (len > maxlen)
442 len = maxlen;
443
444 if (copy_to_user(p, bits, len))
445 return -EFAULT;
446 }
447
448 return len;
449 }
450 #else
451 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
452 unsigned int maxlen, void __user *p, int compat)
453 {
454 int len = compat ?
455 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
456 BITS_TO_LONGS(maxbit) * sizeof(long);
457
458 if (len > maxlen)
459 len = maxlen;
460
461 return copy_to_user(p, bits, len) ? -EFAULT : len;
462 }
463 #endif /* __BIG_ENDIAN */
464
465 #else
466
467 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
468 unsigned int maxlen, void __user *p, int compat)
469 {
470 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
471
472 if (len > maxlen)
473 len = maxlen;
474
475 return copy_to_user(p, bits, len) ? -EFAULT : len;
476 }
477
478 #endif /* CONFIG_COMPAT */
479
480 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
481 {
482 int len;
483
484 if (!str)
485 return -ENOENT;
486
487 len = strlen(str) + 1;
488 if (len > maxlen)
489 len = maxlen;
490
491 return copy_to_user(p, str, len) ? -EFAULT : len;
492 }
493
494 #define OLD_KEY_MAX 0x1ff
495 static int handle_eviocgbit(struct input_dev *dev,
496 unsigned int type, unsigned int size,
497 void __user *p, int compat_mode)
498 {
499 static unsigned long keymax_warn_time;
500 unsigned long *bits;
501 int len;
502
503 switch (type) {
504
505 case 0: bits = dev->evbit; len = EV_MAX; break;
506 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
507 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
508 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
509 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
510 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
511 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
512 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
513 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
514 default: return -EINVAL;
515 }
516
517 /*
518 * Work around bugs in userspace programs that like to do
519 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
520 * should be in bytes, not in bits.
521 */
522 if (type == EV_KEY && size == OLD_KEY_MAX) {
523 len = OLD_KEY_MAX;
524 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
525 printk(KERN_WARNING
526 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
527 "limiting output to %zu bytes. See "
528 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
529 OLD_KEY_MAX,
530 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
531 }
532
533 return bits_to_user(bits, len, size, p, compat_mode);
534 }
535 #undef OLD_KEY_MAX
536
537 static int evdev_handle_get_keycode(struct input_dev *dev,
538 void __user *p, size_t size)
539 {
540 struct input_keymap_entry ke;
541 int error;
542
543 memset(&ke, 0, sizeof(ke));
544
545 if (size == sizeof(unsigned int[2])) {
546 /* legacy case */
547 int __user *ip = (int __user *)p;
548
549 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
550 return -EFAULT;
551
552 ke.len = sizeof(unsigned int);
553 ke.flags = 0;
554
555 error = input_get_keycode(dev, &ke);
556 if (error)
557 return error;
558
559 if (put_user(ke.keycode, ip + 1))
560 return -EFAULT;
561
562 } else {
563 size = min(size, sizeof(ke));
564
565 if (copy_from_user(&ke, p, size))
566 return -EFAULT;
567
568 error = input_get_keycode(dev, &ke);
569 if (error)
570 return error;
571
572 if (copy_to_user(p, &ke, size))
573 return -EFAULT;
574 }
575 return 0;
576 }
577
578 static int evdev_handle_set_keycode(struct input_dev *dev,
579 void __user *p, size_t size)
580 {
581 struct input_keymap_entry ke;
582
583 memset(&ke, 0, sizeof(ke));
584
585 if (size == sizeof(unsigned int[2])) {
586 /* legacy case */
587 int __user *ip = (int __user *)p;
588
589 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
590 return -EFAULT;
591
592 if (get_user(ke.keycode, ip + 1))
593 return -EFAULT;
594
595 ke.len = sizeof(unsigned int);
596 ke.flags = 0;
597
598 } else {
599 size = min(size, sizeof(ke));
600
601 if (copy_from_user(&ke, p, size))
602 return -EFAULT;
603
604 if (ke.len > sizeof(ke.scancode))
605 return -EINVAL;
606 }
607
608 return input_set_keycode(dev, &ke);
609 }
610
611 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
612 void __user *p, int compat_mode)
613 {
614 struct evdev_client *client = file->private_data;
615 struct evdev *evdev = client->evdev;
616 struct input_dev *dev = evdev->handle.dev;
617 struct input_absinfo abs;
618 struct ff_effect effect;
619 int __user *ip = (int __user *)p;
620 unsigned int i, t, u, v;
621 unsigned int size;
622 int error;
623
624 /* First we check for fixed-length commands */
625 switch (cmd) {
626
627 case EVIOCGVERSION:
628 return put_user(EV_VERSION, ip);
629
630 case EVIOCGID:
631 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
632 return -EFAULT;
633 return 0;
634
635 case EVIOCGREP:
636 if (!test_bit(EV_REP, dev->evbit))
637 return -ENOSYS;
638 if (put_user(dev->rep[REP_DELAY], ip))
639 return -EFAULT;
640 if (put_user(dev->rep[REP_PERIOD], ip + 1))
641 return -EFAULT;
642 return 0;
643
644 case EVIOCSREP:
645 if (!test_bit(EV_REP, dev->evbit))
646 return -ENOSYS;
647 if (get_user(u, ip))
648 return -EFAULT;
649 if (get_user(v, ip + 1))
650 return -EFAULT;
651
652 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
653 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
654
655 return 0;
656
657 case EVIOCRMFF:
658 return input_ff_erase(dev, (int)(unsigned long) p, file);
659
660 case EVIOCGEFFECTS:
661 i = test_bit(EV_FF, dev->evbit) ?
662 dev->ff->max_effects : 0;
663 if (put_user(i, ip))
664 return -EFAULT;
665 return 0;
666
667 case EVIOCGRAB:
668 if (p)
669 return evdev_grab(evdev, client);
670 else
671 return evdev_ungrab(evdev, client);
672 }
673
674 size = _IOC_SIZE(cmd);
675
676 /* Now check variable-length commands */
677 #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
678 switch (EVIOC_MASK_SIZE(cmd)) {
679
680 case EVIOCGKEY(0):
681 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
682
683 case EVIOCGLED(0):
684 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
685
686 case EVIOCGSND(0):
687 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
688
689 case EVIOCGSW(0):
690 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
691
692 case EVIOCGNAME(0):
693 return str_to_user(dev->name, size, p);
694
695 case EVIOCGPHYS(0):
696 return str_to_user(dev->phys, size, p);
697
698 case EVIOCGUNIQ(0):
699 return str_to_user(dev->uniq, size, p);
700
701 case EVIOC_MASK_SIZE(EVIOCSFF):
702 if (input_ff_effect_from_user(p, size, &effect))
703 return -EFAULT;
704
705 error = input_ff_upload(dev, &effect, file);
706
707 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
708 return -EFAULT;
709
710 return error;
711
712 case EVIOC_MASK_SIZE(EVIOCGKEYCODE):
713 return evdev_handle_get_keycode(dev, p, size);
714
715 case EVIOC_MASK_SIZE(EVIOCSKEYCODE):
716 return evdev_handle_set_keycode(dev, p, size);
717 }
718
719 /* Multi-number variable-length handlers */
720 if (_IOC_TYPE(cmd) != 'E')
721 return -EINVAL;
722
723 if (_IOC_DIR(cmd) == _IOC_READ) {
724
725 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
726 return handle_eviocgbit(dev,
727 _IOC_NR(cmd) & EV_MAX, size,
728 p, compat_mode);
729
730 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
731
732 t = _IOC_NR(cmd) & ABS_MAX;
733 abs = dev->absinfo[t];
734
735 if (copy_to_user(p, &abs, min_t(size_t,
736 size, sizeof(struct input_absinfo))))
737 return -EFAULT;
738
739 return 0;
740 }
741 }
742
743 if (_IOC_DIR(cmd) == _IOC_READ) {
744
745 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
746
747 t = _IOC_NR(cmd) & ABS_MAX;
748
749 if (copy_from_user(&abs, p, min_t(size_t,
750 size, sizeof(struct input_absinfo))))
751 return -EFAULT;
752
753 if (size < sizeof(struct input_absinfo))
754 abs.resolution = 0;
755
756 /* We can't change number of reserved MT slots */
757 if (t == ABS_MT_SLOT)
758 return -EINVAL;
759
760 /*
761 * Take event lock to ensure that we are not
762 * changing device parameters in the middle
763 * of event.
764 */
765 spin_lock_irq(&dev->event_lock);
766 dev->absinfo[t] = abs;
767 spin_unlock_irq(&dev->event_lock);
768
769 return 0;
770 }
771 }
772
773 return -EINVAL;
774 }
775
776 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
777 void __user *p, int compat_mode)
778 {
779 struct evdev_client *client = file->private_data;
780 struct evdev *evdev = client->evdev;
781 int retval;
782
783 retval = mutex_lock_interruptible(&evdev->mutex);
784 if (retval)
785 return retval;
786
787 if (!evdev->exist) {
788 retval = -ENODEV;
789 goto out;
790 }
791
792 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
793
794 out:
795 mutex_unlock(&evdev->mutex);
796 return retval;
797 }
798
799 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
800 {
801 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
802 }
803
804 #ifdef CONFIG_COMPAT
805 static long evdev_ioctl_compat(struct file *file,
806 unsigned int cmd, unsigned long arg)
807 {
808 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
809 }
810 #endif
811
812 static const struct file_operations evdev_fops = {
813 .owner = THIS_MODULE,
814 .read = evdev_read,
815 .write = evdev_write,
816 .poll = evdev_poll,
817 .open = evdev_open,
818 .release = evdev_release,
819 .unlocked_ioctl = evdev_ioctl,
820 #ifdef CONFIG_COMPAT
821 .compat_ioctl = evdev_ioctl_compat,
822 #endif
823 .fasync = evdev_fasync,
824 .flush = evdev_flush
825 };
826
827 static int evdev_install_chrdev(struct evdev *evdev)
828 {
829 /*
830 * No need to do any locking here as calls to connect and
831 * disconnect are serialized by the input core
832 */
833 evdev_table[evdev->minor] = evdev;
834 return 0;
835 }
836
837 static void evdev_remove_chrdev(struct evdev *evdev)
838 {
839 /*
840 * Lock evdev table to prevent race with evdev_open()
841 */
842 mutex_lock(&evdev_table_mutex);
843 evdev_table[evdev->minor] = NULL;
844 mutex_unlock(&evdev_table_mutex);
845 }
846
847 /*
848 * Mark device non-existent. This disables writes, ioctls and
849 * prevents new users from opening the device. Already posted
850 * blocking reads will stay, however new ones will fail.
851 */
852 static void evdev_mark_dead(struct evdev *evdev)
853 {
854 mutex_lock(&evdev->mutex);
855 evdev->exist = false;
856 mutex_unlock(&evdev->mutex);
857 }
858
859 static void evdev_cleanup(struct evdev *evdev)
860 {
861 struct input_handle *handle = &evdev->handle;
862
863 evdev_mark_dead(evdev);
864 evdev_hangup(evdev);
865 evdev_remove_chrdev(evdev);
866
867 /* evdev is marked dead so no one else accesses evdev->open */
868 if (evdev->open) {
869 input_flush_device(handle, NULL);
870 input_close_device(handle);
871 }
872 }
873
874 /*
875 * Create new evdev device. Note that input core serializes calls
876 * to connect and disconnect so we don't need to lock evdev_table here.
877 */
878 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
879 const struct input_device_id *id)
880 {
881 struct evdev *evdev;
882 int minor;
883 int error;
884
885 for (minor = 0; minor < EVDEV_MINORS; minor++)
886 if (!evdev_table[minor])
887 break;
888
889 if (minor == EVDEV_MINORS) {
890 printk(KERN_ERR "evdev: no more free evdev devices\n");
891 return -ENFILE;
892 }
893
894 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
895 if (!evdev)
896 return -ENOMEM;
897
898 INIT_LIST_HEAD(&evdev->client_list);
899 spin_lock_init(&evdev->client_lock);
900 mutex_init(&evdev->mutex);
901 init_waitqueue_head(&evdev->wait);
902
903 dev_set_name(&evdev->dev, "event%d", minor);
904 evdev->exist = true;
905 evdev->minor = minor;
906
907 evdev->handle.dev = input_get_device(dev);
908 evdev->handle.name = dev_name(&evdev->dev);
909 evdev->handle.handler = handler;
910 evdev->handle.private = evdev;
911
912 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
913 evdev->dev.class = &input_class;
914 evdev->dev.parent = &dev->dev;
915 evdev->dev.release = evdev_free;
916 device_initialize(&evdev->dev);
917
918 error = input_register_handle(&evdev->handle);
919 if (error)
920 goto err_free_evdev;
921
922 error = evdev_install_chrdev(evdev);
923 if (error)
924 goto err_unregister_handle;
925
926 error = device_add(&evdev->dev);
927 if (error)
928 goto err_cleanup_evdev;
929
930 return 0;
931
932 err_cleanup_evdev:
933 evdev_cleanup(evdev);
934 err_unregister_handle:
935 input_unregister_handle(&evdev->handle);
936 err_free_evdev:
937 put_device(&evdev->dev);
938 return error;
939 }
940
941 static void evdev_disconnect(struct input_handle *handle)
942 {
943 struct evdev *evdev = handle->private;
944
945 device_del(&evdev->dev);
946 evdev_cleanup(evdev);
947 input_unregister_handle(handle);
948 put_device(&evdev->dev);
949 }
950
951 static const struct input_device_id evdev_ids[] = {
952 { .driver_info = 1 }, /* Matches all devices */
953 { }, /* Terminating zero entry */
954 };
955
956 MODULE_DEVICE_TABLE(input, evdev_ids);
957
958 static struct input_handler evdev_handler = {
959 .event = evdev_event,
960 .connect = evdev_connect,
961 .disconnect = evdev_disconnect,
962 .fops = &evdev_fops,
963 .minor = EVDEV_MINOR_BASE,
964 .name = "evdev",
965 .id_table = evdev_ids,
966 };
967
968 static int __init evdev_init(void)
969 {
970 return input_register_handler(&evdev_handler);
971 }
972
973 static void __exit evdev_exit(void)
974 {
975 input_unregister_handler(&evdev_handler);
976 }
977
978 module_init(evdev_init);
979 module_exit(evdev_exit);
980
981 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
982 MODULE_DESCRIPTION("Input driver event char devices");
983 MODULE_LICENSE("GPL");
kernel-based virtual machine