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V4L/DVB (6715): ivtv: Remove unnecessary register update
[linux-2.6/verdex.git] / drivers / input / input.c
bloba0be978501ff1c1679374adcde4d13ad84102aa6
1 /*
2 * The input core
3 *
4 * Copyright (c) 1999-2002 Vojtech Pavlik
5 */
6
7 /*
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published by
10 * the Free Software Foundation.
11 */
12
13 #include <linux/init.h>
14 #include <linux/input.h>
15 #include <linux/module.h>
16 #include <linux/random.h>
17 #include <linux/major.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/poll.h>
21 #include <linux/device.h>
22 #include <linux/mutex.h>
23 #include <linux/rcupdate.h>
24
25 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
26 MODULE_DESCRIPTION("Input core");
27 MODULE_LICENSE("GPL");
28
29 #define INPUT_DEVICES 256
30
31 static LIST_HEAD(input_dev_list);
32 static LIST_HEAD(input_handler_list);
33
34 /*
35 * input_mutex protects access to both input_dev_list and input_handler_list.
36 * This also causes input_[un]register_device and input_[un]register_handler
37 * be mutually exclusive which simplifies locking in drivers implementing
38 * input handlers.
39 */
40 static DEFINE_MUTEX(input_mutex);
41
42 static struct input_handler *input_table[8];
43
44 static inline int is_event_supported(unsigned int code,
45 unsigned long *bm, unsigned int max)
46 {
47 return code <= max && test_bit(code, bm);
48 }
49
50 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
51 {
52 if (fuzz) {
53 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
54 return old_val;
55
56 if (value > old_val - fuzz && value < old_val + fuzz)
57 return (old_val * 3 + value) / 4;
58
59 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
60 return (old_val + value) / 2;
61 }
62
63 return value;
64 }
65
66 /*
67 * Pass event through all open handles. This function is called with
68 * dev->event_lock held and interrupts disabled.
69 */
70 static void input_pass_event(struct input_dev *dev,
71 unsigned int type, unsigned int code, int value)
72 {
73 struct input_handle *handle;
74
75 rcu_read_lock();
76
77 handle = rcu_dereference(dev->grab);
78 if (handle)
79 handle->handler->event(handle, type, code, value);
80 else
81 list_for_each_entry_rcu(handle, &dev->h_list, d_node)
82 if (handle->open)
83 handle->handler->event(handle,
84 type, code, value);
85 rcu_read_unlock();
86 }
87
88 /*
89 * Generate software autorepeat event. Note that we take
90 * dev->event_lock here to avoid racing with input_event
91 * which may cause keys get "stuck".
92 */
93 static void input_repeat_key(unsigned long data)
94 {
95 struct input_dev *dev = (void *) data;
96 unsigned long flags;
97
98 spin_lock_irqsave(&dev->event_lock, flags);
99
100 if (test_bit(dev->repeat_key, dev->key) &&
101 is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
102
103 input_pass_event(dev, EV_KEY, dev->repeat_key, 2);
104
105 if (dev->sync) {
106 /*
107 * Only send SYN_REPORT if we are not in a middle
108 * of driver parsing a new hardware packet.
109 * Otherwise assume that the driver will send
110 * SYN_REPORT once it's done.
111 */
112 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
113 }
114
115 if (dev->rep[REP_PERIOD])
116 mod_timer(&dev->timer, jiffies +
117 msecs_to_jiffies(dev->rep[REP_PERIOD]));
118 }
119
120 spin_unlock_irqrestore(&dev->event_lock, flags);
121 }
122
123 static void input_start_autorepeat(struct input_dev *dev, int code)
124 {
125 if (test_bit(EV_REP, dev->evbit) &&
126 dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
127 dev->timer.data) {
128 dev->repeat_key = code;
129 mod_timer(&dev->timer,
130 jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
131 }
132 }
133
134 #define INPUT_IGNORE_EVENT 0
135 #define INPUT_PASS_TO_HANDLERS 1
136 #define INPUT_PASS_TO_DEVICE 2
137 #define INPUT_PASS_TO_ALL (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
138
139 static void input_handle_event(struct input_dev *dev,
140 unsigned int type, unsigned int code, int value)
141 {
142 int disposition = INPUT_IGNORE_EVENT;
143
144 switch (type) {
145
146 case EV_SYN:
147 switch (code) {
148 case SYN_CONFIG:
149 disposition = INPUT_PASS_TO_ALL;
150 break;
151
152 case SYN_REPORT:
153 if (!dev->sync) {
154 dev->sync = 1;
155 disposition = INPUT_PASS_TO_HANDLERS;
156 }
157 break;
158 }
159 break;
160
161 case EV_KEY:
162 if (is_event_supported(code, dev->keybit, KEY_MAX) &&
163 !!test_bit(code, dev->key) != value) {
164
165 if (value != 2) {
166 __change_bit(code, dev->key);
167 if (value)
168 input_start_autorepeat(dev, code);
169 }
170
171 disposition = INPUT_PASS_TO_HANDLERS;
172 }
173 break;
174
175 case EV_SW:
176 if (is_event_supported(code, dev->swbit, SW_MAX) &&
177 !!test_bit(code, dev->sw) != value) {
178
179 __change_bit(code, dev->sw);
180 disposition = INPUT_PASS_TO_HANDLERS;
181 }
182 break;
183
184 case EV_ABS:
185 if (is_event_supported(code, dev->absbit, ABS_MAX)) {
186
187 value = input_defuzz_abs_event(value,
188 dev->abs[code], dev->absfuzz[code]);
189
190 if (dev->abs[code] != value) {
191 dev->abs[code] = value;
192 disposition = INPUT_PASS_TO_HANDLERS;
193 }
194 }
195 break;
196
197 case EV_REL:
198 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
199 disposition = INPUT_PASS_TO_HANDLERS;
200
201 break;
202
203 case EV_MSC:
204 if (is_event_supported(code, dev->mscbit, MSC_MAX))
205 disposition = INPUT_PASS_TO_ALL;
206
207 break;
208
209 case EV_LED:
210 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
211 !!test_bit(code, dev->led) != value) {
212
213 __change_bit(code, dev->led);
214 disposition = INPUT_PASS_TO_ALL;
215 }
216 break;
217
218 case EV_SND:
219 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
220
221 if (!!test_bit(code, dev->snd) != !!value)
222 __change_bit(code, dev->snd);
223 disposition = INPUT_PASS_TO_ALL;
224 }
225 break;
226
227 case EV_REP:
228 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
229 dev->rep[code] = value;
230 disposition = INPUT_PASS_TO_ALL;
231 }
232 break;
233
234 case EV_FF:
235 if (value >= 0)
236 disposition = INPUT_PASS_TO_ALL;
237 break;
238
239 case EV_PWR:
240 disposition = INPUT_PASS_TO_ALL;
241 break;
242 }
243
244 if (type != EV_SYN)
245 dev->sync = 0;
246
247 if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
248 dev->event(dev, type, code, value);
249
250 if (disposition & INPUT_PASS_TO_HANDLERS)
251 input_pass_event(dev, type, code, value);
252 }
253
254 /**
255 * input_event() - report new input event
256 * @dev: device that generated the event
257 * @type: type of the event
258 * @code: event code
259 * @value: value of the event
260 *
261 * This function should be used by drivers implementing various input
262 * devices. See also input_inject_event().
263 */
264
265 void input_event(struct input_dev *dev,
266 unsigned int type, unsigned int code, int value)
267 {
268 unsigned long flags;
269
270 if (is_event_supported(type, dev->evbit, EV_MAX)) {
271
272 spin_lock_irqsave(&dev->event_lock, flags);
273 add_input_randomness(type, code, value);
274 input_handle_event(dev, type, code, value);
275 spin_unlock_irqrestore(&dev->event_lock, flags);
276 }
277 }
278 EXPORT_SYMBOL(input_event);
279
280 /**
281 * input_inject_event() - send input event from input handler
282 * @handle: input handle to send event through
283 * @type: type of the event
284 * @code: event code
285 * @value: value of the event
286 *
287 * Similar to input_event() but will ignore event if device is
288 * "grabbed" and handle injecting event is not the one that owns
289 * the device.
290 */
291 void input_inject_event(struct input_handle *handle,
292 unsigned int type, unsigned int code, int value)
293 {
294 struct input_dev *dev = handle->dev;
295 struct input_handle *grab;
296 unsigned long flags;
297
298 if (is_event_supported(type, dev->evbit, EV_MAX)) {
299 spin_lock_irqsave(&dev->event_lock, flags);
300
301 rcu_read_lock();
302 grab = rcu_dereference(dev->grab);
303 if (!grab || grab == handle)
304 input_handle_event(dev, type, code, value);
305 rcu_read_unlock();
306
307 spin_unlock_irqrestore(&dev->event_lock, flags);
308 }
309 }
310 EXPORT_SYMBOL(input_inject_event);
311
312 /**
313 * input_grab_device - grabs device for exclusive use
314 * @handle: input handle that wants to own the device
315 *
316 * When a device is grabbed by an input handle all events generated by
317 * the device are delivered only to this handle. Also events injected
318 * by other input handles are ignored while device is grabbed.
319 */
320 int input_grab_device(struct input_handle *handle)
321 {
322 struct input_dev *dev = handle->dev;
323 int retval;
324
325 retval = mutex_lock_interruptible(&dev->mutex);
326 if (retval)
327 return retval;
328
329 if (dev->grab) {
330 retval = -EBUSY;
331 goto out;
332 }
333
334 rcu_assign_pointer(dev->grab, handle);
335 synchronize_rcu();
336
337 out:
338 mutex_unlock(&dev->mutex);
339 return retval;
340 }
341 EXPORT_SYMBOL(input_grab_device);
342
343 static void __input_release_device(struct input_handle *handle)
344 {
345 struct input_dev *dev = handle->dev;
346
347 if (dev->grab == handle) {
348 rcu_assign_pointer(dev->grab, NULL);
349 /* Make sure input_pass_event() notices that grab is gone */
350 synchronize_rcu();
351
352 list_for_each_entry(handle, &dev->h_list, d_node)
353 if (handle->open && handle->handler->start)
354 handle->handler->start(handle);
355 }
356 }
357
358 /**
359 * input_release_device - release previously grabbed device
360 * @handle: input handle that owns the device
361 *
362 * Releases previously grabbed device so that other input handles can
363 * start receiving input events. Upon release all handlers attached
364 * to the device have their start() method called so they have a change
365 * to synchronize device state with the rest of the system.
366 */
367 void input_release_device(struct input_handle *handle)
368 {
369 struct input_dev *dev = handle->dev;
370
371 mutex_lock(&dev->mutex);
372 __input_release_device(handle);
373 mutex_unlock(&dev->mutex);
374 }
375 EXPORT_SYMBOL(input_release_device);
376
377 /**
378 * input_open_device - open input device
379 * @handle: handle through which device is being accessed
380 *
381 * This function should be called by input handlers when they
382 * want to start receive events from given input device.
383 */
384 int input_open_device(struct input_handle *handle)
385 {
386 struct input_dev *dev = handle->dev;
387 int retval;
388
389 retval = mutex_lock_interruptible(&dev->mutex);
390 if (retval)
391 return retval;
392
393 if (dev->going_away) {
394 retval = -ENODEV;
395 goto out;
396 }
397
398 handle->open++;
399
400 if (!dev->users++ && dev->open)
401 retval = dev->open(dev);
402
403 if (retval) {
404 dev->users--;
405 if (!--handle->open) {
406 /*
407 * Make sure we are not delivering any more events
408 * through this handle
409 */
410 synchronize_rcu();
411 }
412 }
413
414 out:
415 mutex_unlock(&dev->mutex);
416 return retval;
417 }
418 EXPORT_SYMBOL(input_open_device);
419
420 int input_flush_device(struct input_handle *handle, struct file *file)
421 {
422 struct input_dev *dev = handle->dev;
423 int retval;
424
425 retval = mutex_lock_interruptible(&dev->mutex);
426 if (retval)
427 return retval;
428
429 if (dev->flush)
430 retval = dev->flush(dev, file);
431
432 mutex_unlock(&dev->mutex);
433 return retval;
434 }
435 EXPORT_SYMBOL(input_flush_device);
436
437 /**
438 * input_close_device - close input device
439 * @handle: handle through which device is being accessed
440 *
441 * This function should be called by input handlers when they
442 * want to stop receive events from given input device.
443 */
444 void input_close_device(struct input_handle *handle)
445 {
446 struct input_dev *dev = handle->dev;
447
448 mutex_lock(&dev->mutex);
449
450 __input_release_device(handle);
451
452 if (!--dev->users && dev->close)
453 dev->close(dev);
454
455 if (!--handle->open) {
456 /*
457 * synchronize_rcu() makes sure that input_pass_event()
458 * completed and that no more input events are delivered
459 * through this handle
460 */
461 synchronize_rcu();
462 }
463
464 mutex_unlock(&dev->mutex);
465 }
466 EXPORT_SYMBOL(input_close_device);
467
468 /*
469 * Prepare device for unregistering
470 */
471 static void input_disconnect_device(struct input_dev *dev)
472 {
473 struct input_handle *handle;
474 int code;
475
476 /*
477 * Mark device as going away. Note that we take dev->mutex here
478 * not to protect access to dev->going_away but rather to ensure
479 * that there are no threads in the middle of input_open_device()
480 */
481 mutex_lock(&dev->mutex);
482 dev->going_away = 1;
483 mutex_unlock(&dev->mutex);
484
485 spin_lock_irq(&dev->event_lock);
486
487 /*
488 * Simulate keyup events for all pressed keys so that handlers
489 * are not left with "stuck" keys. The driver may continue
490 * generate events even after we done here but they will not
491 * reach any handlers.
492 */
493 if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
494 for (code = 0; code <= KEY_MAX; code++) {
495 if (is_event_supported(code, dev->keybit, KEY_MAX) &&
496 test_bit(code, dev->key)) {
497 input_pass_event(dev, EV_KEY, code, 0);
498 }
499 }
500 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
501 }
502
503 list_for_each_entry(handle, &dev->h_list, d_node)
504 handle->open = 0;
505
506 spin_unlock_irq(&dev->event_lock);
507 }
508
509 static int input_fetch_keycode(struct input_dev *dev, int scancode)
510 {
511 switch (dev->keycodesize) {
512 case 1:
513 return ((u8 *)dev->keycode)[scancode];
514
515 case 2:
516 return ((u16 *)dev->keycode)[scancode];
517
518 default:
519 return ((u32 *)dev->keycode)[scancode];
520 }
521 }
522
523 static int input_default_getkeycode(struct input_dev *dev,
524 int scancode, int *keycode)
525 {
526 if (!dev->keycodesize)
527 return -EINVAL;
528
529 if (scancode < 0 || scancode >= dev->keycodemax)
530 return -EINVAL;
531
532 *keycode = input_fetch_keycode(dev, scancode);
533
534 return 0;
535 }
536
537 static int input_default_setkeycode(struct input_dev *dev,
538 int scancode, int keycode)
539 {
540 int old_keycode;
541 int i;
542
543 if (scancode < 0 || scancode >= dev->keycodemax)
544 return -EINVAL;
545
546 if (keycode < 0 || keycode > KEY_MAX)
547 return -EINVAL;
548
549 if (!dev->keycodesize)
550 return -EINVAL;
551
552 if (dev->keycodesize < sizeof(keycode) && (keycode >> (dev->keycodesize * 8)))
553 return -EINVAL;
554
555 switch (dev->keycodesize) {
556 case 1: {
557 u8 *k = (u8 *)dev->keycode;
558 old_keycode = k[scancode];
559 k[scancode] = keycode;
560 break;
561 }
562 case 2: {
563 u16 *k = (u16 *)dev->keycode;
564 old_keycode = k[scancode];
565 k[scancode] = keycode;
566 break;
567 }
568 default: {
569 u32 *k = (u32 *)dev->keycode;
570 old_keycode = k[scancode];
571 k[scancode] = keycode;
572 break;
573 }
574 }
575
576 clear_bit(old_keycode, dev->keybit);
577 set_bit(keycode, dev->keybit);
578
579 for (i = 0; i < dev->keycodemax; i++) {
580 if (input_fetch_keycode(dev, i) == old_keycode) {
581 set_bit(old_keycode, dev->keybit);
582 break; /* Setting the bit twice is useless, so break */
583 }
584 }
585
586 return 0;
587 }
588
589
590 #define MATCH_BIT(bit, max) \
591 for (i = 0; i < BITS_TO_LONGS(max); i++) \
592 if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
593 break; \
594 if (i != BITS_TO_LONGS(max)) \
595 continue;
596
597 static const struct input_device_id *input_match_device(const struct input_device_id *id,
598 struct input_dev *dev)
599 {
600 int i;
601
602 for (; id->flags || id->driver_info; id++) {
603
604 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
605 if (id->bustype != dev->id.bustype)
606 continue;
607
608 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
609 if (id->vendor != dev->id.vendor)
610 continue;
611
612 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
613 if (id->product != dev->id.product)
614 continue;
615
616 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
617 if (id->version != dev->id.version)
618 continue;
619
620 MATCH_BIT(evbit, EV_MAX);
621 MATCH_BIT(keybit, KEY_MAX);
622 MATCH_BIT(relbit, REL_MAX);
623 MATCH_BIT(absbit, ABS_MAX);
624 MATCH_BIT(mscbit, MSC_MAX);
625 MATCH_BIT(ledbit, LED_MAX);
626 MATCH_BIT(sndbit, SND_MAX);
627 MATCH_BIT(ffbit, FF_MAX);
628 MATCH_BIT(swbit, SW_MAX);
629
630 return id;
631 }
632
633 return NULL;
634 }
635
636 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
637 {
638 const struct input_device_id *id;
639 int error;
640
641 if (handler->blacklist && input_match_device(handler->blacklist, dev))
642 return -ENODEV;
643
644 id = input_match_device(handler->id_table, dev);
645 if (!id)
646 return -ENODEV;
647
648 error = handler->connect(handler, dev, id);
649 if (error && error != -ENODEV)
650 printk(KERN_ERR
651 "input: failed to attach handler %s to device %s, "
652 "error: %d\n",
653 handler->name, kobject_name(&dev->dev.kobj), error);
654
655 return error;
656 }
657
658
659 #ifdef CONFIG_PROC_FS
660
661 static struct proc_dir_entry *proc_bus_input_dir;
662 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
663 static int input_devices_state;
664
665 static inline void input_wakeup_procfs_readers(void)
666 {
667 input_devices_state++;
668 wake_up(&input_devices_poll_wait);
669 }
670
671 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
672 {
673 int state = input_devices_state;
674
675 poll_wait(file, &input_devices_poll_wait, wait);
676 if (state != input_devices_state)
677 return POLLIN | POLLRDNORM;
678
679 return 0;
680 }
681
682 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
683 {
684 if (mutex_lock_interruptible(&input_mutex))
685 return NULL;
686
687 return seq_list_start(&input_dev_list, *pos);
688 }
689
690 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
691 {
692 return seq_list_next(v, &input_dev_list, pos);
693 }
694
695 static void input_devices_seq_stop(struct seq_file *seq, void *v)
696 {
697 mutex_unlock(&input_mutex);
698 }
699
700 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
701 unsigned long *bitmap, int max)
702 {
703 int i;
704
705 for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
706 if (bitmap[i])
707 break;
708
709 seq_printf(seq, "B: %s=", name);
710 for (; i >= 0; i--)
711 seq_printf(seq, "%lx%s", bitmap[i], i > 0 ? " " : "");
712 seq_putc(seq, '\n');
713 }
714
715 static int input_devices_seq_show(struct seq_file *seq, void *v)
716 {
717 struct input_dev *dev = container_of(v, struct input_dev, node);
718 const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
719 struct input_handle *handle;
720
721 seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
722 dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
723
724 seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
725 seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
726 seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
727 seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
728 seq_printf(seq, "H: Handlers=");
729
730 list_for_each_entry(handle, &dev->h_list, d_node)
731 seq_printf(seq, "%s ", handle->name);
732 seq_putc(seq, '\n');
733
734 input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
735 if (test_bit(EV_KEY, dev->evbit))
736 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
737 if (test_bit(EV_REL, dev->evbit))
738 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
739 if (test_bit(EV_ABS, dev->evbit))
740 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
741 if (test_bit(EV_MSC, dev->evbit))
742 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
743 if (test_bit(EV_LED, dev->evbit))
744 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
745 if (test_bit(EV_SND, dev->evbit))
746 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
747 if (test_bit(EV_FF, dev->evbit))
748 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
749 if (test_bit(EV_SW, dev->evbit))
750 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
751
752 seq_putc(seq, '\n');
753
754 kfree(path);
755 return 0;
756 }
757
758 static struct seq_operations input_devices_seq_ops = {
759 .start = input_devices_seq_start,
760 .next = input_devices_seq_next,
761 .stop = input_devices_seq_stop,
762 .show = input_devices_seq_show,
763 };
764
765 static int input_proc_devices_open(struct inode *inode, struct file *file)
766 {
767 return seq_open(file, &input_devices_seq_ops);
768 }
769
770 static const struct file_operations input_devices_fileops = {
771 .owner = THIS_MODULE,
772 .open = input_proc_devices_open,
773 .poll = input_proc_devices_poll,
774 .read = seq_read,
775 .llseek = seq_lseek,
776 .release = seq_release,
777 };
778
779 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
780 {
781 if (mutex_lock_interruptible(&input_mutex))
782 return NULL;
783
784 seq->private = (void *)(unsigned long)*pos;
785 return seq_list_start(&input_handler_list, *pos);
786 }
787
788 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
789 {
790 seq->private = (void *)(unsigned long)(*pos + 1);
791 return seq_list_next(v, &input_handler_list, pos);
792 }
793
794 static void input_handlers_seq_stop(struct seq_file *seq, void *v)
795 {
796 mutex_unlock(&input_mutex);
797 }
798
799 static int input_handlers_seq_show(struct seq_file *seq, void *v)
800 {
801 struct input_handler *handler = container_of(v, struct input_handler, node);
802
803 seq_printf(seq, "N: Number=%ld Name=%s",
804 (unsigned long)seq->private, handler->name);
805 if (handler->fops)
806 seq_printf(seq, " Minor=%d", handler->minor);
807 seq_putc(seq, '\n');
808
809 return 0;
810 }
811 static struct seq_operations input_handlers_seq_ops = {
812 .start = input_handlers_seq_start,
813 .next = input_handlers_seq_next,
814 .stop = input_handlers_seq_stop,
815 .show = input_handlers_seq_show,
816 };
817
818 static int input_proc_handlers_open(struct inode *inode, struct file *file)
819 {
820 return seq_open(file, &input_handlers_seq_ops);
821 }
822
823 static const struct file_operations input_handlers_fileops = {
824 .owner = THIS_MODULE,
825 .open = input_proc_handlers_open,
826 .read = seq_read,
827 .llseek = seq_lseek,
828 .release = seq_release,
829 };
830
831 static int __init input_proc_init(void)
832 {
833 struct proc_dir_entry *entry;
834
835 proc_bus_input_dir = proc_mkdir("input", proc_bus);
836 if (!proc_bus_input_dir)
837 return -ENOMEM;
838
839 proc_bus_input_dir->owner = THIS_MODULE;
840
841 entry = create_proc_entry("devices", 0, proc_bus_input_dir);
842 if (!entry)
843 goto fail1;
844
845 entry->owner = THIS_MODULE;
846 entry->proc_fops = &input_devices_fileops;
847
848 entry = create_proc_entry("handlers", 0, proc_bus_input_dir);
849 if (!entry)
850 goto fail2;
851
852 entry->owner = THIS_MODULE;
853 entry->proc_fops = &input_handlers_fileops;
854
855 return 0;
856
857 fail2: remove_proc_entry("devices", proc_bus_input_dir);
858 fail1: remove_proc_entry("input", proc_bus);
859 return -ENOMEM;
860 }
861
862 static void input_proc_exit(void)
863 {
864 remove_proc_entry("devices", proc_bus_input_dir);
865 remove_proc_entry("handlers", proc_bus_input_dir);
866 remove_proc_entry("input", proc_bus);
867 }
868
869 #else /* !CONFIG_PROC_FS */
870 static inline void input_wakeup_procfs_readers(void) { }
871 static inline int input_proc_init(void) { return 0; }
872 static inline void input_proc_exit(void) { }
873 #endif
874
875 #define INPUT_DEV_STRING_ATTR_SHOW(name) \
876 static ssize_t input_dev_show_##name(struct device *dev, \
877 struct device_attribute *attr, \
878 char *buf) \
879 { \
880 struct input_dev *input_dev = to_input_dev(dev); \
881 \
882 return scnprintf(buf, PAGE_SIZE, "%s\n", \
883 input_dev->name ? input_dev->name : ""); \
884 } \
885 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
886
887 INPUT_DEV_STRING_ATTR_SHOW(name);
888 INPUT_DEV_STRING_ATTR_SHOW(phys);
889 INPUT_DEV_STRING_ATTR_SHOW(uniq);
890
891 static int input_print_modalias_bits(char *buf, int size,
892 char name, unsigned long *bm,
893 unsigned int min_bit, unsigned int max_bit)
894 {
895 int len = 0, i;
896
897 len += snprintf(buf, max(size, 0), "%c", name);
898 for (i = min_bit; i < max_bit; i++)
899 if (bm[BIT_WORD(i)] & BIT_MASK(i))
900 len += snprintf(buf + len, max(size - len, 0), "%X,", i);
901 return len;
902 }
903
904 static int input_print_modalias(char *buf, int size, struct input_dev *id,
905 int add_cr)
906 {
907 int len;
908
909 len = snprintf(buf, max(size, 0),
910 "input:b%04Xv%04Xp%04Xe%04X-",
911 id->id.bustype, id->id.vendor,
912 id->id.product, id->id.version);
913
914 len += input_print_modalias_bits(buf + len, size - len,
915 'e', id->evbit, 0, EV_MAX);
916 len += input_print_modalias_bits(buf + len, size - len,
917 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
918 len += input_print_modalias_bits(buf + len, size - len,
919 'r', id->relbit, 0, REL_MAX);
920 len += input_print_modalias_bits(buf + len, size - len,
921 'a', id->absbit, 0, ABS_MAX);
922 len += input_print_modalias_bits(buf + len, size - len,
923 'm', id->mscbit, 0, MSC_MAX);
924 len += input_print_modalias_bits(buf + len, size - len,
925 'l', id->ledbit, 0, LED_MAX);
926 len += input_print_modalias_bits(buf + len, size - len,
927 's', id->sndbit, 0, SND_MAX);
928 len += input_print_modalias_bits(buf + len, size - len,
929 'f', id->ffbit, 0, FF_MAX);
930 len += input_print_modalias_bits(buf + len, size - len,
931 'w', id->swbit, 0, SW_MAX);
932
933 if (add_cr)
934 len += snprintf(buf + len, max(size - len, 0), "\n");
935
936 return len;
937 }
938
939 static ssize_t input_dev_show_modalias(struct device *dev,
940 struct device_attribute *attr,
941 char *buf)
942 {
943 struct input_dev *id = to_input_dev(dev);
944 ssize_t len;
945
946 len = input_print_modalias(buf, PAGE_SIZE, id, 1);
947
948 return min_t(int, len, PAGE_SIZE);
949 }
950 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
951
952 static struct attribute *input_dev_attrs[] = {
953 &dev_attr_name.attr,
954 &dev_attr_phys.attr,
955 &dev_attr_uniq.attr,
956 &dev_attr_modalias.attr,
957 NULL
958 };
959
960 static struct attribute_group input_dev_attr_group = {
961 .attrs = input_dev_attrs,
962 };
963
964 #define INPUT_DEV_ID_ATTR(name) \
965 static ssize_t input_dev_show_id_##name(struct device *dev, \
966 struct device_attribute *attr, \
967 char *buf) \
968 { \
969 struct input_dev *input_dev = to_input_dev(dev); \
970 return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
971 } \
972 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
973
974 INPUT_DEV_ID_ATTR(bustype);
975 INPUT_DEV_ID_ATTR(vendor);
976 INPUT_DEV_ID_ATTR(product);
977 INPUT_DEV_ID_ATTR(version);
978
979 static struct attribute *input_dev_id_attrs[] = {
980 &dev_attr_bustype.attr,
981 &dev_attr_vendor.attr,
982 &dev_attr_product.attr,
983 &dev_attr_version.attr,
984 NULL
985 };
986
987 static struct attribute_group input_dev_id_attr_group = {
988 .name = "id",
989 .attrs = input_dev_id_attrs,
990 };
991
992 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
993 int max, int add_cr)
994 {
995 int i;
996 int len = 0;
997
998 for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
999 if (bitmap[i])
1000 break;
1001
1002 for (; i >= 0; i--)
1003 len += snprintf(buf + len, max(buf_size - len, 0),
1004 "%lx%s", bitmap[i], i > 0 ? " " : "");
1005
1006 if (add_cr)
1007 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1008
1009 return len;
1010 }
1011
1012 #define INPUT_DEV_CAP_ATTR(ev, bm) \
1013 static ssize_t input_dev_show_cap_##bm(struct device *dev, \
1014 struct device_attribute *attr, \
1015 char *buf) \
1016 { \
1017 struct input_dev *input_dev = to_input_dev(dev); \
1018 int len = input_print_bitmap(buf, PAGE_SIZE, \
1019 input_dev->bm##bit, ev##_MAX, 1); \
1020 return min_t(int, len, PAGE_SIZE); \
1021 } \
1022 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1023
1024 INPUT_DEV_CAP_ATTR(EV, ev);
1025 INPUT_DEV_CAP_ATTR(KEY, key);
1026 INPUT_DEV_CAP_ATTR(REL, rel);
1027 INPUT_DEV_CAP_ATTR(ABS, abs);
1028 INPUT_DEV_CAP_ATTR(MSC, msc);
1029 INPUT_DEV_CAP_ATTR(LED, led);
1030 INPUT_DEV_CAP_ATTR(SND, snd);
1031 INPUT_DEV_CAP_ATTR(FF, ff);
1032 INPUT_DEV_CAP_ATTR(SW, sw);
1033
1034 static struct attribute *input_dev_caps_attrs[] = {
1035 &dev_attr_ev.attr,
1036 &dev_attr_key.attr,
1037 &dev_attr_rel.attr,
1038 &dev_attr_abs.attr,
1039 &dev_attr_msc.attr,
1040 &dev_attr_led.attr,
1041 &dev_attr_snd.attr,
1042 &dev_attr_ff.attr,
1043 &dev_attr_sw.attr,
1044 NULL
1045 };
1046
1047 static struct attribute_group input_dev_caps_attr_group = {
1048 .name = "capabilities",
1049 .attrs = input_dev_caps_attrs,
1050 };
1051
1052 static struct attribute_group *input_dev_attr_groups[] = {
1053 &input_dev_attr_group,
1054 &input_dev_id_attr_group,
1055 &input_dev_caps_attr_group,
1056 NULL
1057 };
1058
1059 static void input_dev_release(struct device *device)
1060 {
1061 struct input_dev *dev = to_input_dev(device);
1062
1063 input_ff_destroy(dev);
1064 kfree(dev);
1065
1066 module_put(THIS_MODULE);
1067 }
1068
1069 /*
1070 * Input uevent interface - loading event handlers based on
1071 * device bitfields.
1072 */
1073 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1074 const char *name, unsigned long *bitmap, int max)
1075 {
1076 int len;
1077
1078 if (add_uevent_var(env, "%s=", name))
1079 return -ENOMEM;
1080
1081 len = input_print_bitmap(&env->buf[env->buflen - 1],
1082 sizeof(env->buf) - env->buflen,
1083 bitmap, max, 0);
1084 if (len >= (sizeof(env->buf) - env->buflen))
1085 return -ENOMEM;
1086
1087 env->buflen += len;
1088 return 0;
1089 }
1090
1091 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1092 struct input_dev *dev)
1093 {
1094 int len;
1095
1096 if (add_uevent_var(env, "MODALIAS="))
1097 return -ENOMEM;
1098
1099 len = input_print_modalias(&env->buf[env->buflen - 1],
1100 sizeof(env->buf) - env->buflen,
1101 dev, 0);
1102 if (len >= (sizeof(env->buf) - env->buflen))
1103 return -ENOMEM;
1104
1105 env->buflen += len;
1106 return 0;
1107 }
1108
1109 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \
1110 do { \
1111 int err = add_uevent_var(env, fmt, val); \
1112 if (err) \
1113 return err; \
1114 } while (0)
1115
1116 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \
1117 do { \
1118 int err = input_add_uevent_bm_var(env, name, bm, max); \
1119 if (err) \
1120 return err; \
1121 } while (0)
1122
1123 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \
1124 do { \
1125 int err = input_add_uevent_modalias_var(env, dev); \
1126 if (err) \
1127 return err; \
1128 } while (0)
1129
1130 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1131 {
1132 struct input_dev *dev = to_input_dev(device);
1133
1134 INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1135 dev->id.bustype, dev->id.vendor,
1136 dev->id.product, dev->id.version);
1137 if (dev->name)
1138 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1139 if (dev->phys)
1140 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1141 if (dev->uniq)
1142 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1143
1144 INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1145 if (test_bit(EV_KEY, dev->evbit))
1146 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1147 if (test_bit(EV_REL, dev->evbit))
1148 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1149 if (test_bit(EV_ABS, dev->evbit))
1150 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1151 if (test_bit(EV_MSC, dev->evbit))
1152 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1153 if (test_bit(EV_LED, dev->evbit))
1154 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1155 if (test_bit(EV_SND, dev->evbit))
1156 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1157 if (test_bit(EV_FF, dev->evbit))
1158 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1159 if (test_bit(EV_SW, dev->evbit))
1160 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1161
1162 INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1163
1164 return 0;
1165 }
1166
1167 static struct device_type input_dev_type = {
1168 .groups = input_dev_attr_groups,
1169 .release = input_dev_release,
1170 .uevent = input_dev_uevent,
1171 };
1172
1173 struct class input_class = {
1174 .name = "input",
1175 };
1176 EXPORT_SYMBOL_GPL(input_class);
1177
1178 /**
1179 * input_allocate_device - allocate memory for new input device
1180 *
1181 * Returns prepared struct input_dev or NULL.
1182 *
1183 * NOTE: Use input_free_device() to free devices that have not been
1184 * registered; input_unregister_device() should be used for already
1185 * registered devices.
1186 */
1187 struct input_dev *input_allocate_device(void)
1188 {
1189 struct input_dev *dev;
1190
1191 dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
1192 if (dev) {
1193 dev->dev.type = &input_dev_type;
1194 dev->dev.class = &input_class;
1195 device_initialize(&dev->dev);
1196 mutex_init(&dev->mutex);
1197 spin_lock_init(&dev->event_lock);
1198 INIT_LIST_HEAD(&dev->h_list);
1199 INIT_LIST_HEAD(&dev->node);
1200
1201 __module_get(THIS_MODULE);
1202 }
1203
1204 return dev;
1205 }
1206 EXPORT_SYMBOL(input_allocate_device);
1207
1208 /**
1209 * input_free_device - free memory occupied by input_dev structure
1210 * @dev: input device to free
1211 *
1212 * This function should only be used if input_register_device()
1213 * was not called yet or if it failed. Once device was registered
1214 * use input_unregister_device() and memory will be freed once last
1215 * reference to the device is dropped.
1216 *
1217 * Device should be allocated by input_allocate_device().
1218 *
1219 * NOTE: If there are references to the input device then memory
1220 * will not be freed until last reference is dropped.
1221 */
1222 void input_free_device(struct input_dev *dev)
1223 {
1224 if (dev)
1225 input_put_device(dev);
1226 }
1227 EXPORT_SYMBOL(input_free_device);
1228
1229 /**
1230 * input_set_capability - mark device as capable of a certain event
1231 * @dev: device that is capable of emitting or accepting event
1232 * @type: type of the event (EV_KEY, EV_REL, etc...)
1233 * @code: event code
1234 *
1235 * In addition to setting up corresponding bit in appropriate capability
1236 * bitmap the function also adjusts dev->evbit.
1237 */
1238 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1239 {
1240 switch (type) {
1241 case EV_KEY:
1242 __set_bit(code, dev->keybit);
1243 break;
1244
1245 case EV_REL:
1246 __set_bit(code, dev->relbit);
1247 break;
1248
1249 case EV_ABS:
1250 __set_bit(code, dev->absbit);
1251 break;
1252
1253 case EV_MSC:
1254 __set_bit(code, dev->mscbit);
1255 break;
1256
1257 case EV_SW:
1258 __set_bit(code, dev->swbit);
1259 break;
1260
1261 case EV_LED:
1262 __set_bit(code, dev->ledbit);
1263 break;
1264
1265 case EV_SND:
1266 __set_bit(code, dev->sndbit);
1267 break;
1268
1269 case EV_FF:
1270 __set_bit(code, dev->ffbit);
1271 break;
1272
1273 case EV_PWR:
1274 /* do nothing */
1275 break;
1276
1277 default:
1278 printk(KERN_ERR
1279 "input_set_capability: unknown type %u (code %u)\n",
1280 type, code);
1281 dump_stack();
1282 return;
1283 }
1284
1285 __set_bit(type, dev->evbit);
1286 }
1287 EXPORT_SYMBOL(input_set_capability);
1288
1289 /**
1290 * input_register_device - register device with input core
1291 * @dev: device to be registered
1292 *
1293 * This function registers device with input core. The device must be
1294 * allocated with input_allocate_device() and all it's capabilities
1295 * set up before registering.
1296 * If function fails the device must be freed with input_free_device().
1297 * Once device has been successfully registered it can be unregistered
1298 * with input_unregister_device(); input_free_device() should not be
1299 * called in this case.
1300 */
1301 int input_register_device(struct input_dev *dev)
1302 {
1303 static atomic_t input_no = ATOMIC_INIT(0);
1304 struct input_handler *handler;
1305 const char *path;
1306 int error;
1307
1308 __set_bit(EV_SYN, dev->evbit);
1309
1310 /*
1311 * If delay and period are pre-set by the driver, then autorepeating
1312 * is handled by the driver itself and we don't do it in input.c.
1313 */
1314
1315 init_timer(&dev->timer);
1316 if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
1317 dev->timer.data = (long) dev;
1318 dev->timer.function = input_repeat_key;
1319 dev->rep[REP_DELAY] = 250;
1320 dev->rep[REP_PERIOD] = 33;
1321 }
1322
1323 if (!dev->getkeycode)
1324 dev->getkeycode = input_default_getkeycode;
1325
1326 if (!dev->setkeycode)
1327 dev->setkeycode = input_default_setkeycode;
1328
1329 snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
1330 "input%ld", (unsigned long) atomic_inc_return(&input_no) - 1);
1331
1332 if (dev->cdev.dev)
1333 dev->dev.parent = dev->cdev.dev;
1334
1335 error = device_add(&dev->dev);
1336 if (error)
1337 return error;
1338
1339 path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1340 printk(KERN_INFO "input: %s as %s\n",
1341 dev->name ? dev->name : "Unspecified device", path ? path : "N/A");
1342 kfree(path);
1343
1344 error = mutex_lock_interruptible(&input_mutex);
1345 if (error) {
1346 device_del(&dev->dev);
1347 return error;
1348 }
1349
1350 list_add_tail(&dev->node, &input_dev_list);
1351
1352 list_for_each_entry(handler, &input_handler_list, node)
1353 input_attach_handler(dev, handler);
1354
1355 input_wakeup_procfs_readers();
1356
1357 mutex_unlock(&input_mutex);
1358
1359 return 0;
1360 }
1361 EXPORT_SYMBOL(input_register_device);
1362
1363 /**
1364 * input_unregister_device - unregister previously registered device
1365 * @dev: device to be unregistered
1366 *
1367 * This function unregisters an input device. Once device is unregistered
1368 * the caller should not try to access it as it may get freed at any moment.
1369 */
1370 void input_unregister_device(struct input_dev *dev)
1371 {
1372 struct input_handle *handle, *next;
1373
1374 input_disconnect_device(dev);
1375
1376 mutex_lock(&input_mutex);
1377
1378 list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
1379 handle->handler->disconnect(handle);
1380 WARN_ON(!list_empty(&dev->h_list));
1381
1382 del_timer_sync(&dev->timer);
1383 list_del_init(&dev->node);
1384
1385 input_wakeup_procfs_readers();
1386
1387 mutex_unlock(&input_mutex);
1388
1389 device_unregister(&dev->dev);
1390 }
1391 EXPORT_SYMBOL(input_unregister_device);
1392
1393 /**
1394 * input_register_handler - register a new input handler
1395 * @handler: handler to be registered
1396 *
1397 * This function registers a new input handler (interface) for input
1398 * devices in the system and attaches it to all input devices that
1399 * are compatible with the handler.
1400 */
1401 int input_register_handler(struct input_handler *handler)
1402 {
1403 struct input_dev *dev;
1404 int retval;
1405
1406 retval = mutex_lock_interruptible(&input_mutex);
1407 if (retval)
1408 return retval;
1409
1410 INIT_LIST_HEAD(&handler->h_list);
1411
1412 if (handler->fops != NULL) {
1413 if (input_table[handler->minor >> 5]) {
1414 retval = -EBUSY;
1415 goto out;
1416 }
1417 input_table[handler->minor >> 5] = handler;
1418 }
1419
1420 list_add_tail(&handler->node, &input_handler_list);
1421
1422 list_for_each_entry(dev, &input_dev_list, node)
1423 input_attach_handler(dev, handler);
1424
1425 input_wakeup_procfs_readers();
1426
1427 out:
1428 mutex_unlock(&input_mutex);
1429 return retval;
1430 }
1431 EXPORT_SYMBOL(input_register_handler);
1432
1433 /**
1434 * input_unregister_handler - unregisters an input handler
1435 * @handler: handler to be unregistered
1436 *
1437 * This function disconnects a handler from its input devices and
1438 * removes it from lists of known handlers.
1439 */
1440 void input_unregister_handler(struct input_handler *handler)
1441 {
1442 struct input_handle *handle, *next;
1443
1444 mutex_lock(&input_mutex);
1445
1446 list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
1447 handler->disconnect(handle);
1448 WARN_ON(!list_empty(&handler->h_list));
1449
1450 list_del_init(&handler->node);
1451
1452 if (handler->fops != NULL)
1453 input_table[handler->minor >> 5] = NULL;
1454
1455 input_wakeup_procfs_readers();
1456
1457 mutex_unlock(&input_mutex);
1458 }
1459 EXPORT_SYMBOL(input_unregister_handler);
1460
1461 /**
1462 * input_register_handle - register a new input handle
1463 * @handle: handle to register
1464 *
1465 * This function puts a new input handle onto device's
1466 * and handler's lists so that events can flow through
1467 * it once it is opened using input_open_device().
1468 *
1469 * This function is supposed to be called from handler's
1470 * connect() method.
1471 */
1472 int input_register_handle(struct input_handle *handle)
1473 {
1474 struct input_handler *handler = handle->handler;
1475 struct input_dev *dev = handle->dev;
1476 int error;
1477
1478 /*
1479 * We take dev->mutex here to prevent race with
1480 * input_release_device().
1481 */
1482 error = mutex_lock_interruptible(&dev->mutex);
1483 if (error)
1484 return error;
1485 list_add_tail_rcu(&handle->d_node, &dev->h_list);
1486 mutex_unlock(&dev->mutex);
1487 synchronize_rcu();
1488
1489 /*
1490 * Since we are supposed to be called from ->connect()
1491 * which is mutually exclusive with ->disconnect()
1492 * we can't be racing with input_unregister_handle()
1493 * and so separate lock is not needed here.
1494 */
1495 list_add_tail(&handle->h_node, &handler->h_list);
1496
1497 if (handler->start)
1498 handler->start(handle);
1499
1500 return 0;
1501 }
1502 EXPORT_SYMBOL(input_register_handle);
1503
1504 /**
1505 * input_unregister_handle - unregister an input handle
1506 * @handle: handle to unregister
1507 *
1508 * This function removes input handle from device's
1509 * and handler's lists.
1510 *
1511 * This function is supposed to be called from handler's
1512 * disconnect() method.
1513 */
1514 void input_unregister_handle(struct input_handle *handle)
1515 {
1516 struct input_dev *dev = handle->dev;
1517
1518 list_del_init(&handle->h_node);
1519
1520 /*
1521 * Take dev->mutex to prevent race with input_release_device().
1522 */
1523 mutex_lock(&dev->mutex);
1524 list_del_rcu(&handle->d_node);
1525 mutex_unlock(&dev->mutex);
1526 synchronize_rcu();
1527 }
1528 EXPORT_SYMBOL(input_unregister_handle);
1529
1530 static int input_open_file(struct inode *inode, struct file *file)
1531 {
1532 struct input_handler *handler = input_table[iminor(inode) >> 5];
1533 const struct file_operations *old_fops, *new_fops = NULL;
1534 int err;
1535
1536 /* No load-on-demand here? */
1537 if (!handler || !(new_fops = fops_get(handler->fops)))
1538 return -ENODEV;
1539
1540 /*
1541 * That's _really_ odd. Usually NULL ->open means "nothing special",
1542 * not "no device". Oh, well...
1543 */
1544 if (!new_fops->open) {
1545 fops_put(new_fops);
1546 return -ENODEV;
1547 }
1548 old_fops = file->f_op;
1549 file->f_op = new_fops;
1550
1551 err = new_fops->open(inode, file);
1552
1553 if (err) {
1554 fops_put(file->f_op);
1555 file->f_op = fops_get(old_fops);
1556 }
1557 fops_put(old_fops);
1558 return err;
1559 }
1560
1561 static const struct file_operations input_fops = {
1562 .owner = THIS_MODULE,
1563 .open = input_open_file,
1564 };
1565
1566 static int __init input_init(void)
1567 {
1568 int err;
1569
1570 err = class_register(&input_class);
1571 if (err) {
1572 printk(KERN_ERR "input: unable to register input_dev class\n");
1573 return err;
1574 }
1575
1576 err = input_proc_init();
1577 if (err)
1578 goto fail1;
1579
1580 err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
1581 if (err) {
1582 printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
1583 goto fail2;
1584 }
1585
1586 return 0;
1587
1588 fail2: input_proc_exit();
1589 fail1: class_unregister(&input_class);
1590 return err;
1591 }
1592
1593 static void __exit input_exit(void)
1594 {
1595 input_proc_exit();
1596 unregister_chrdev(INPUT_MAJOR, "input");
1597 class_unregister(&input_class);
1598 }
1599
1600 subsys_initcall(input_init);
1601 module_exit(input_exit);
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