xref: /openbmc/linux/drivers/input/input.c (revision b04b4f78)
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 #include <linux/smp_lock.h>
25 
26 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
27 MODULE_DESCRIPTION("Input core");
28 MODULE_LICENSE("GPL");
29 
30 #define INPUT_DEVICES	256
31 
32 /*
33  * EV_ABS events which should not be cached are listed here.
34  */
35 static unsigned int input_abs_bypass_init_data[] __initdata = {
36 	ABS_MT_TOUCH_MAJOR,
37 	ABS_MT_TOUCH_MINOR,
38 	ABS_MT_WIDTH_MAJOR,
39 	ABS_MT_WIDTH_MINOR,
40 	ABS_MT_ORIENTATION,
41 	ABS_MT_POSITION_X,
42 	ABS_MT_POSITION_Y,
43 	ABS_MT_TOOL_TYPE,
44 	ABS_MT_BLOB_ID,
45 	0
46 };
47 static unsigned long input_abs_bypass[BITS_TO_LONGS(ABS_CNT)];
48 
49 static LIST_HEAD(input_dev_list);
50 static LIST_HEAD(input_handler_list);
51 
52 /*
53  * input_mutex protects access to both input_dev_list and input_handler_list.
54  * This also causes input_[un]register_device and input_[un]register_handler
55  * be mutually exclusive which simplifies locking in drivers implementing
56  * input handlers.
57  */
58 static DEFINE_MUTEX(input_mutex);
59 
60 static struct input_handler *input_table[8];
61 
62 static inline int is_event_supported(unsigned int code,
63 				     unsigned long *bm, unsigned int max)
64 {
65 	return code <= max && test_bit(code, bm);
66 }
67 
68 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
69 {
70 	if (fuzz) {
71 		if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
72 			return old_val;
73 
74 		if (value > old_val - fuzz && value < old_val + fuzz)
75 			return (old_val * 3 + value) / 4;
76 
77 		if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
78 			return (old_val + value) / 2;
79 	}
80 
81 	return value;
82 }
83 
84 /*
85  * Pass event through all open handles. This function is called with
86  * dev->event_lock held and interrupts disabled.
87  */
88 static void input_pass_event(struct input_dev *dev,
89 			     unsigned int type, unsigned int code, int value)
90 {
91 	struct input_handle *handle;
92 
93 	rcu_read_lock();
94 
95 	handle = rcu_dereference(dev->grab);
96 	if (handle)
97 		handle->handler->event(handle, type, code, value);
98 	else
99 		list_for_each_entry_rcu(handle, &dev->h_list, d_node)
100 			if (handle->open)
101 				handle->handler->event(handle,
102 							type, code, value);
103 	rcu_read_unlock();
104 }
105 
106 /*
107  * Generate software autorepeat event. Note that we take
108  * dev->event_lock here to avoid racing with input_event
109  * which may cause keys get "stuck".
110  */
111 static void input_repeat_key(unsigned long data)
112 {
113 	struct input_dev *dev = (void *) data;
114 	unsigned long flags;
115 
116 	spin_lock_irqsave(&dev->event_lock, flags);
117 
118 	if (test_bit(dev->repeat_key, dev->key) &&
119 	    is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
120 
121 		input_pass_event(dev, EV_KEY, dev->repeat_key, 2);
122 
123 		if (dev->sync) {
124 			/*
125 			 * Only send SYN_REPORT if we are not in a middle
126 			 * of driver parsing a new hardware packet.
127 			 * Otherwise assume that the driver will send
128 			 * SYN_REPORT once it's done.
129 			 */
130 			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
131 		}
132 
133 		if (dev->rep[REP_PERIOD])
134 			mod_timer(&dev->timer, jiffies +
135 					msecs_to_jiffies(dev->rep[REP_PERIOD]));
136 	}
137 
138 	spin_unlock_irqrestore(&dev->event_lock, flags);
139 }
140 
141 static void input_start_autorepeat(struct input_dev *dev, int code)
142 {
143 	if (test_bit(EV_REP, dev->evbit) &&
144 	    dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
145 	    dev->timer.data) {
146 		dev->repeat_key = code;
147 		mod_timer(&dev->timer,
148 			  jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
149 	}
150 }
151 
152 static void input_stop_autorepeat(struct input_dev *dev)
153 {
154 	del_timer(&dev->timer);
155 }
156 
157 #define INPUT_IGNORE_EVENT	0
158 #define INPUT_PASS_TO_HANDLERS	1
159 #define INPUT_PASS_TO_DEVICE	2
160 #define INPUT_PASS_TO_ALL	(INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
161 
162 static void input_handle_event(struct input_dev *dev,
163 			       unsigned int type, unsigned int code, int value)
164 {
165 	int disposition = INPUT_IGNORE_EVENT;
166 
167 	switch (type) {
168 
169 	case EV_SYN:
170 		switch (code) {
171 		case SYN_CONFIG:
172 			disposition = INPUT_PASS_TO_ALL;
173 			break;
174 
175 		case SYN_REPORT:
176 			if (!dev->sync) {
177 				dev->sync = 1;
178 				disposition = INPUT_PASS_TO_HANDLERS;
179 			}
180 			break;
181 		case SYN_MT_REPORT:
182 			dev->sync = 0;
183 			disposition = INPUT_PASS_TO_HANDLERS;
184 			break;
185 		}
186 		break;
187 
188 	case EV_KEY:
189 		if (is_event_supported(code, dev->keybit, KEY_MAX) &&
190 		    !!test_bit(code, dev->key) != value) {
191 
192 			if (value != 2) {
193 				__change_bit(code, dev->key);
194 				if (value)
195 					input_start_autorepeat(dev, code);
196 				else
197 					input_stop_autorepeat(dev);
198 			}
199 
200 			disposition = INPUT_PASS_TO_HANDLERS;
201 		}
202 		break;
203 
204 	case EV_SW:
205 		if (is_event_supported(code, dev->swbit, SW_MAX) &&
206 		    !!test_bit(code, dev->sw) != value) {
207 
208 			__change_bit(code, dev->sw);
209 			disposition = INPUT_PASS_TO_HANDLERS;
210 		}
211 		break;
212 
213 	case EV_ABS:
214 		if (is_event_supported(code, dev->absbit, ABS_MAX)) {
215 
216 			if (test_bit(code, input_abs_bypass)) {
217 				disposition = INPUT_PASS_TO_HANDLERS;
218 				break;
219 			}
220 
221 			value = input_defuzz_abs_event(value,
222 					dev->abs[code], dev->absfuzz[code]);
223 
224 			if (dev->abs[code] != value) {
225 				dev->abs[code] = value;
226 				disposition = INPUT_PASS_TO_HANDLERS;
227 			}
228 		}
229 		break;
230 
231 	case EV_REL:
232 		if (is_event_supported(code, dev->relbit, REL_MAX) && value)
233 			disposition = INPUT_PASS_TO_HANDLERS;
234 
235 		break;
236 
237 	case EV_MSC:
238 		if (is_event_supported(code, dev->mscbit, MSC_MAX))
239 			disposition = INPUT_PASS_TO_ALL;
240 
241 		break;
242 
243 	case EV_LED:
244 		if (is_event_supported(code, dev->ledbit, LED_MAX) &&
245 		    !!test_bit(code, dev->led) != value) {
246 
247 			__change_bit(code, dev->led);
248 			disposition = INPUT_PASS_TO_ALL;
249 		}
250 		break;
251 
252 	case EV_SND:
253 		if (is_event_supported(code, dev->sndbit, SND_MAX)) {
254 
255 			if (!!test_bit(code, dev->snd) != !!value)
256 				__change_bit(code, dev->snd);
257 			disposition = INPUT_PASS_TO_ALL;
258 		}
259 		break;
260 
261 	case EV_REP:
262 		if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
263 			dev->rep[code] = value;
264 			disposition = INPUT_PASS_TO_ALL;
265 		}
266 		break;
267 
268 	case EV_FF:
269 		if (value >= 0)
270 			disposition = INPUT_PASS_TO_ALL;
271 		break;
272 
273 	case EV_PWR:
274 		disposition = INPUT_PASS_TO_ALL;
275 		break;
276 	}
277 
278 	if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
279 		dev->sync = 0;
280 
281 	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
282 		dev->event(dev, type, code, value);
283 
284 	if (disposition & INPUT_PASS_TO_HANDLERS)
285 		input_pass_event(dev, type, code, value);
286 }
287 
288 /**
289  * input_event() - report new input event
290  * @dev: device that generated the event
291  * @type: type of the event
292  * @code: event code
293  * @value: value of the event
294  *
295  * This function should be used by drivers implementing various input
296  * devices. See also input_inject_event().
297  */
298 
299 void input_event(struct input_dev *dev,
300 		 unsigned int type, unsigned int code, int value)
301 {
302 	unsigned long flags;
303 
304 	if (is_event_supported(type, dev->evbit, EV_MAX)) {
305 
306 		spin_lock_irqsave(&dev->event_lock, flags);
307 		add_input_randomness(type, code, value);
308 		input_handle_event(dev, type, code, value);
309 		spin_unlock_irqrestore(&dev->event_lock, flags);
310 	}
311 }
312 EXPORT_SYMBOL(input_event);
313 
314 /**
315  * input_inject_event() - send input event from input handler
316  * @handle: input handle to send event through
317  * @type: type of the event
318  * @code: event code
319  * @value: value of the event
320  *
321  * Similar to input_event() but will ignore event if device is
322  * "grabbed" and handle injecting event is not the one that owns
323  * the device.
324  */
325 void input_inject_event(struct input_handle *handle,
326 			unsigned int type, unsigned int code, int value)
327 {
328 	struct input_dev *dev = handle->dev;
329 	struct input_handle *grab;
330 	unsigned long flags;
331 
332 	if (is_event_supported(type, dev->evbit, EV_MAX)) {
333 		spin_lock_irqsave(&dev->event_lock, flags);
334 
335 		rcu_read_lock();
336 		grab = rcu_dereference(dev->grab);
337 		if (!grab || grab == handle)
338 			input_handle_event(dev, type, code, value);
339 		rcu_read_unlock();
340 
341 		spin_unlock_irqrestore(&dev->event_lock, flags);
342 	}
343 }
344 EXPORT_SYMBOL(input_inject_event);
345 
346 /**
347  * input_grab_device - grabs device for exclusive use
348  * @handle: input handle that wants to own the device
349  *
350  * When a device is grabbed by an input handle all events generated by
351  * the device are delivered only to this handle. Also events injected
352  * by other input handles are ignored while device is grabbed.
353  */
354 int input_grab_device(struct input_handle *handle)
355 {
356 	struct input_dev *dev = handle->dev;
357 	int retval;
358 
359 	retval = mutex_lock_interruptible(&dev->mutex);
360 	if (retval)
361 		return retval;
362 
363 	if (dev->grab) {
364 		retval = -EBUSY;
365 		goto out;
366 	}
367 
368 	rcu_assign_pointer(dev->grab, handle);
369 	synchronize_rcu();
370 
371  out:
372 	mutex_unlock(&dev->mutex);
373 	return retval;
374 }
375 EXPORT_SYMBOL(input_grab_device);
376 
377 static void __input_release_device(struct input_handle *handle)
378 {
379 	struct input_dev *dev = handle->dev;
380 
381 	if (dev->grab == handle) {
382 		rcu_assign_pointer(dev->grab, NULL);
383 		/* Make sure input_pass_event() notices that grab is gone */
384 		synchronize_rcu();
385 
386 		list_for_each_entry(handle, &dev->h_list, d_node)
387 			if (handle->open && handle->handler->start)
388 				handle->handler->start(handle);
389 	}
390 }
391 
392 /**
393  * input_release_device - release previously grabbed device
394  * @handle: input handle that owns the device
395  *
396  * Releases previously grabbed device so that other input handles can
397  * start receiving input events. Upon release all handlers attached
398  * to the device have their start() method called so they have a change
399  * to synchronize device state with the rest of the system.
400  */
401 void input_release_device(struct input_handle *handle)
402 {
403 	struct input_dev *dev = handle->dev;
404 
405 	mutex_lock(&dev->mutex);
406 	__input_release_device(handle);
407 	mutex_unlock(&dev->mutex);
408 }
409 EXPORT_SYMBOL(input_release_device);
410 
411 /**
412  * input_open_device - open input device
413  * @handle: handle through which device is being accessed
414  *
415  * This function should be called by input handlers when they
416  * want to start receive events from given input device.
417  */
418 int input_open_device(struct input_handle *handle)
419 {
420 	struct input_dev *dev = handle->dev;
421 	int retval;
422 
423 	retval = mutex_lock_interruptible(&dev->mutex);
424 	if (retval)
425 		return retval;
426 
427 	if (dev->going_away) {
428 		retval = -ENODEV;
429 		goto out;
430 	}
431 
432 	handle->open++;
433 
434 	if (!dev->users++ && dev->open)
435 		retval = dev->open(dev);
436 
437 	if (retval) {
438 		dev->users--;
439 		if (!--handle->open) {
440 			/*
441 			 * Make sure we are not delivering any more events
442 			 * through this handle
443 			 */
444 			synchronize_rcu();
445 		}
446 	}
447 
448  out:
449 	mutex_unlock(&dev->mutex);
450 	return retval;
451 }
452 EXPORT_SYMBOL(input_open_device);
453 
454 int input_flush_device(struct input_handle *handle, struct file *file)
455 {
456 	struct input_dev *dev = handle->dev;
457 	int retval;
458 
459 	retval = mutex_lock_interruptible(&dev->mutex);
460 	if (retval)
461 		return retval;
462 
463 	if (dev->flush)
464 		retval = dev->flush(dev, file);
465 
466 	mutex_unlock(&dev->mutex);
467 	return retval;
468 }
469 EXPORT_SYMBOL(input_flush_device);
470 
471 /**
472  * input_close_device - close input device
473  * @handle: handle through which device is being accessed
474  *
475  * This function should be called by input handlers when they
476  * want to stop receive events from given input device.
477  */
478 void input_close_device(struct input_handle *handle)
479 {
480 	struct input_dev *dev = handle->dev;
481 
482 	mutex_lock(&dev->mutex);
483 
484 	__input_release_device(handle);
485 
486 	if (!--dev->users && dev->close)
487 		dev->close(dev);
488 
489 	if (!--handle->open) {
490 		/*
491 		 * synchronize_rcu() makes sure that input_pass_event()
492 		 * completed and that no more input events are delivered
493 		 * through this handle
494 		 */
495 		synchronize_rcu();
496 	}
497 
498 	mutex_unlock(&dev->mutex);
499 }
500 EXPORT_SYMBOL(input_close_device);
501 
502 /*
503  * Prepare device for unregistering
504  */
505 static void input_disconnect_device(struct input_dev *dev)
506 {
507 	struct input_handle *handle;
508 	int code;
509 
510 	/*
511 	 * Mark device as going away. Note that we take dev->mutex here
512 	 * not to protect access to dev->going_away but rather to ensure
513 	 * that there are no threads in the middle of input_open_device()
514 	 */
515 	mutex_lock(&dev->mutex);
516 	dev->going_away = 1;
517 	mutex_unlock(&dev->mutex);
518 
519 	spin_lock_irq(&dev->event_lock);
520 
521 	/*
522 	 * Simulate keyup events for all pressed keys so that handlers
523 	 * are not left with "stuck" keys. The driver may continue
524 	 * generate events even after we done here but they will not
525 	 * reach any handlers.
526 	 */
527 	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
528 		for (code = 0; code <= KEY_MAX; code++) {
529 			if (is_event_supported(code, dev->keybit, KEY_MAX) &&
530 			    __test_and_clear_bit(code, dev->key)) {
531 				input_pass_event(dev, EV_KEY, code, 0);
532 			}
533 		}
534 		input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
535 	}
536 
537 	list_for_each_entry(handle, &dev->h_list, d_node)
538 		handle->open = 0;
539 
540 	spin_unlock_irq(&dev->event_lock);
541 }
542 
543 static int input_fetch_keycode(struct input_dev *dev, int scancode)
544 {
545 	switch (dev->keycodesize) {
546 		case 1:
547 			return ((u8 *)dev->keycode)[scancode];
548 
549 		case 2:
550 			return ((u16 *)dev->keycode)[scancode];
551 
552 		default:
553 			return ((u32 *)dev->keycode)[scancode];
554 	}
555 }
556 
557 static int input_default_getkeycode(struct input_dev *dev,
558 				    int scancode, int *keycode)
559 {
560 	if (!dev->keycodesize)
561 		return -EINVAL;
562 
563 	if (scancode >= dev->keycodemax)
564 		return -EINVAL;
565 
566 	*keycode = input_fetch_keycode(dev, scancode);
567 
568 	return 0;
569 }
570 
571 static int input_default_setkeycode(struct input_dev *dev,
572 				    int scancode, int keycode)
573 {
574 	int old_keycode;
575 	int i;
576 
577 	if (scancode >= dev->keycodemax)
578 		return -EINVAL;
579 
580 	if (!dev->keycodesize)
581 		return -EINVAL;
582 
583 	if (dev->keycodesize < sizeof(keycode) && (keycode >> (dev->keycodesize * 8)))
584 		return -EINVAL;
585 
586 	switch (dev->keycodesize) {
587 		case 1: {
588 			u8 *k = (u8 *)dev->keycode;
589 			old_keycode = k[scancode];
590 			k[scancode] = keycode;
591 			break;
592 		}
593 		case 2: {
594 			u16 *k = (u16 *)dev->keycode;
595 			old_keycode = k[scancode];
596 			k[scancode] = keycode;
597 			break;
598 		}
599 		default: {
600 			u32 *k = (u32 *)dev->keycode;
601 			old_keycode = k[scancode];
602 			k[scancode] = keycode;
603 			break;
604 		}
605 	}
606 
607 	clear_bit(old_keycode, dev->keybit);
608 	set_bit(keycode, dev->keybit);
609 
610 	for (i = 0; i < dev->keycodemax; i++) {
611 		if (input_fetch_keycode(dev, i) == old_keycode) {
612 			set_bit(old_keycode, dev->keybit);
613 			break; /* Setting the bit twice is useless, so break */
614 		}
615 	}
616 
617 	return 0;
618 }
619 
620 /**
621  * input_get_keycode - retrieve keycode currently mapped to a given scancode
622  * @dev: input device which keymap is being queried
623  * @scancode: scancode (or its equivalent for device in question) for which
624  *	keycode is needed
625  * @keycode: result
626  *
627  * This function should be called by anyone interested in retrieving current
628  * keymap. Presently keyboard and evdev handlers use it.
629  */
630 int input_get_keycode(struct input_dev *dev, int scancode, int *keycode)
631 {
632 	if (scancode < 0)
633 		return -EINVAL;
634 
635 	return dev->getkeycode(dev, scancode, keycode);
636 }
637 EXPORT_SYMBOL(input_get_keycode);
638 
639 /**
640  * input_get_keycode - assign new keycode to a given scancode
641  * @dev: input device which keymap is being updated
642  * @scancode: scancode (or its equivalent for device in question)
643  * @keycode: new keycode to be assigned to the scancode
644  *
645  * This function should be called by anyone needing to update current
646  * keymap. Presently keyboard and evdev handlers use it.
647  */
648 int input_set_keycode(struct input_dev *dev, int scancode, int keycode)
649 {
650 	unsigned long flags;
651 	int old_keycode;
652 	int retval;
653 
654 	if (scancode < 0)
655 		return -EINVAL;
656 
657 	if (keycode < 0 || keycode > KEY_MAX)
658 		return -EINVAL;
659 
660 	spin_lock_irqsave(&dev->event_lock, flags);
661 
662 	retval = dev->getkeycode(dev, scancode, &old_keycode);
663 	if (retval)
664 		goto out;
665 
666 	retval = dev->setkeycode(dev, scancode, keycode);
667 	if (retval)
668 		goto out;
669 
670 	/*
671 	 * Simulate keyup event if keycode is not present
672 	 * in the keymap anymore
673 	 */
674 	if (test_bit(EV_KEY, dev->evbit) &&
675 	    !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
676 	    __test_and_clear_bit(old_keycode, dev->key)) {
677 
678 		input_pass_event(dev, EV_KEY, old_keycode, 0);
679 		if (dev->sync)
680 			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
681 	}
682 
683  out:
684 	spin_unlock_irqrestore(&dev->event_lock, flags);
685 
686 	return retval;
687 }
688 EXPORT_SYMBOL(input_set_keycode);
689 
690 #define MATCH_BIT(bit, max) \
691 		for (i = 0; i < BITS_TO_LONGS(max); i++) \
692 			if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
693 				break; \
694 		if (i != BITS_TO_LONGS(max)) \
695 			continue;
696 
697 static const struct input_device_id *input_match_device(const struct input_device_id *id,
698 							struct input_dev *dev)
699 {
700 	int i;
701 
702 	for (; id->flags || id->driver_info; id++) {
703 
704 		if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
705 			if (id->bustype != dev->id.bustype)
706 				continue;
707 
708 		if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
709 			if (id->vendor != dev->id.vendor)
710 				continue;
711 
712 		if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
713 			if (id->product != dev->id.product)
714 				continue;
715 
716 		if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
717 			if (id->version != dev->id.version)
718 				continue;
719 
720 		MATCH_BIT(evbit,  EV_MAX);
721 		MATCH_BIT(keybit, KEY_MAX);
722 		MATCH_BIT(relbit, REL_MAX);
723 		MATCH_BIT(absbit, ABS_MAX);
724 		MATCH_BIT(mscbit, MSC_MAX);
725 		MATCH_BIT(ledbit, LED_MAX);
726 		MATCH_BIT(sndbit, SND_MAX);
727 		MATCH_BIT(ffbit,  FF_MAX);
728 		MATCH_BIT(swbit,  SW_MAX);
729 
730 		return id;
731 	}
732 
733 	return NULL;
734 }
735 
736 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
737 {
738 	const struct input_device_id *id;
739 	int error;
740 
741 	if (handler->blacklist && input_match_device(handler->blacklist, dev))
742 		return -ENODEV;
743 
744 	id = input_match_device(handler->id_table, dev);
745 	if (!id)
746 		return -ENODEV;
747 
748 	error = handler->connect(handler, dev, id);
749 	if (error && error != -ENODEV)
750 		printk(KERN_ERR
751 			"input: failed to attach handler %s to device %s, "
752 			"error: %d\n",
753 			handler->name, kobject_name(&dev->dev.kobj), error);
754 
755 	return error;
756 }
757 
758 
759 #ifdef CONFIG_PROC_FS
760 
761 static struct proc_dir_entry *proc_bus_input_dir;
762 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
763 static int input_devices_state;
764 
765 static inline void input_wakeup_procfs_readers(void)
766 {
767 	input_devices_state++;
768 	wake_up(&input_devices_poll_wait);
769 }
770 
771 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
772 {
773 	poll_wait(file, &input_devices_poll_wait, wait);
774 	if (file->f_version != input_devices_state) {
775 		file->f_version = input_devices_state;
776 		return POLLIN | POLLRDNORM;
777 	}
778 
779 	return 0;
780 }
781 
782 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
783 {
784 	if (mutex_lock_interruptible(&input_mutex))
785 		return NULL;
786 
787 	return seq_list_start(&input_dev_list, *pos);
788 }
789 
790 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
791 {
792 	return seq_list_next(v, &input_dev_list, pos);
793 }
794 
795 static void input_devices_seq_stop(struct seq_file *seq, void *v)
796 {
797 	mutex_unlock(&input_mutex);
798 }
799 
800 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
801 				   unsigned long *bitmap, int max)
802 {
803 	int i;
804 
805 	for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
806 		if (bitmap[i])
807 			break;
808 
809 	seq_printf(seq, "B: %s=", name);
810 	for (; i >= 0; i--)
811 		seq_printf(seq, "%lx%s", bitmap[i], i > 0 ? " " : "");
812 	seq_putc(seq, '\n');
813 }
814 
815 static int input_devices_seq_show(struct seq_file *seq, void *v)
816 {
817 	struct input_dev *dev = container_of(v, struct input_dev, node);
818 	const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
819 	struct input_handle *handle;
820 
821 	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
822 		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
823 
824 	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
825 	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
826 	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
827 	seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
828 	seq_printf(seq, "H: Handlers=");
829 
830 	list_for_each_entry(handle, &dev->h_list, d_node)
831 		seq_printf(seq, "%s ", handle->name);
832 	seq_putc(seq, '\n');
833 
834 	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
835 	if (test_bit(EV_KEY, dev->evbit))
836 		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
837 	if (test_bit(EV_REL, dev->evbit))
838 		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
839 	if (test_bit(EV_ABS, dev->evbit))
840 		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
841 	if (test_bit(EV_MSC, dev->evbit))
842 		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
843 	if (test_bit(EV_LED, dev->evbit))
844 		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
845 	if (test_bit(EV_SND, dev->evbit))
846 		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
847 	if (test_bit(EV_FF, dev->evbit))
848 		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
849 	if (test_bit(EV_SW, dev->evbit))
850 		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
851 
852 	seq_putc(seq, '\n');
853 
854 	kfree(path);
855 	return 0;
856 }
857 
858 static const struct seq_operations input_devices_seq_ops = {
859 	.start	= input_devices_seq_start,
860 	.next	= input_devices_seq_next,
861 	.stop	= input_devices_seq_stop,
862 	.show	= input_devices_seq_show,
863 };
864 
865 static int input_proc_devices_open(struct inode *inode, struct file *file)
866 {
867 	return seq_open(file, &input_devices_seq_ops);
868 }
869 
870 static const struct file_operations input_devices_fileops = {
871 	.owner		= THIS_MODULE,
872 	.open		= input_proc_devices_open,
873 	.poll		= input_proc_devices_poll,
874 	.read		= seq_read,
875 	.llseek		= seq_lseek,
876 	.release	= seq_release,
877 };
878 
879 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
880 {
881 	if (mutex_lock_interruptible(&input_mutex))
882 		return NULL;
883 
884 	seq->private = (void *)(unsigned long)*pos;
885 	return seq_list_start(&input_handler_list, *pos);
886 }
887 
888 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
889 {
890 	seq->private = (void *)(unsigned long)(*pos + 1);
891 	return seq_list_next(v, &input_handler_list, pos);
892 }
893 
894 static void input_handlers_seq_stop(struct seq_file *seq, void *v)
895 {
896 	mutex_unlock(&input_mutex);
897 }
898 
899 static int input_handlers_seq_show(struct seq_file *seq, void *v)
900 {
901 	struct input_handler *handler = container_of(v, struct input_handler, node);
902 
903 	seq_printf(seq, "N: Number=%ld Name=%s",
904 		   (unsigned long)seq->private, handler->name);
905 	if (handler->fops)
906 		seq_printf(seq, " Minor=%d", handler->minor);
907 	seq_putc(seq, '\n');
908 
909 	return 0;
910 }
911 static const struct seq_operations input_handlers_seq_ops = {
912 	.start	= input_handlers_seq_start,
913 	.next	= input_handlers_seq_next,
914 	.stop	= input_handlers_seq_stop,
915 	.show	= input_handlers_seq_show,
916 };
917 
918 static int input_proc_handlers_open(struct inode *inode, struct file *file)
919 {
920 	return seq_open(file, &input_handlers_seq_ops);
921 }
922 
923 static const struct file_operations input_handlers_fileops = {
924 	.owner		= THIS_MODULE,
925 	.open		= input_proc_handlers_open,
926 	.read		= seq_read,
927 	.llseek		= seq_lseek,
928 	.release	= seq_release,
929 };
930 
931 static int __init input_proc_init(void)
932 {
933 	struct proc_dir_entry *entry;
934 
935 	proc_bus_input_dir = proc_mkdir("bus/input", NULL);
936 	if (!proc_bus_input_dir)
937 		return -ENOMEM;
938 
939 	entry = proc_create("devices", 0, proc_bus_input_dir,
940 			    &input_devices_fileops);
941 	if (!entry)
942 		goto fail1;
943 
944 	entry = proc_create("handlers", 0, proc_bus_input_dir,
945 			    &input_handlers_fileops);
946 	if (!entry)
947 		goto fail2;
948 
949 	return 0;
950 
951  fail2:	remove_proc_entry("devices", proc_bus_input_dir);
952  fail1: remove_proc_entry("bus/input", NULL);
953 	return -ENOMEM;
954 }
955 
956 static void input_proc_exit(void)
957 {
958 	remove_proc_entry("devices", proc_bus_input_dir);
959 	remove_proc_entry("handlers", proc_bus_input_dir);
960 	remove_proc_entry("bus/input", NULL);
961 }
962 
963 #else /* !CONFIG_PROC_FS */
964 static inline void input_wakeup_procfs_readers(void) { }
965 static inline int input_proc_init(void) { return 0; }
966 static inline void input_proc_exit(void) { }
967 #endif
968 
969 #define INPUT_DEV_STRING_ATTR_SHOW(name)				\
970 static ssize_t input_dev_show_##name(struct device *dev,		\
971 				     struct device_attribute *attr,	\
972 				     char *buf)				\
973 {									\
974 	struct input_dev *input_dev = to_input_dev(dev);		\
975 									\
976 	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
977 			 input_dev->name ? input_dev->name : "");	\
978 }									\
979 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
980 
981 INPUT_DEV_STRING_ATTR_SHOW(name);
982 INPUT_DEV_STRING_ATTR_SHOW(phys);
983 INPUT_DEV_STRING_ATTR_SHOW(uniq);
984 
985 static int input_print_modalias_bits(char *buf, int size,
986 				     char name, unsigned long *bm,
987 				     unsigned int min_bit, unsigned int max_bit)
988 {
989 	int len = 0, i;
990 
991 	len += snprintf(buf, max(size, 0), "%c", name);
992 	for (i = min_bit; i < max_bit; i++)
993 		if (bm[BIT_WORD(i)] & BIT_MASK(i))
994 			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
995 	return len;
996 }
997 
998 static int input_print_modalias(char *buf, int size, struct input_dev *id,
999 				int add_cr)
1000 {
1001 	int len;
1002 
1003 	len = snprintf(buf, max(size, 0),
1004 		       "input:b%04Xv%04Xp%04Xe%04X-",
1005 		       id->id.bustype, id->id.vendor,
1006 		       id->id.product, id->id.version);
1007 
1008 	len += input_print_modalias_bits(buf + len, size - len,
1009 				'e', id->evbit, 0, EV_MAX);
1010 	len += input_print_modalias_bits(buf + len, size - len,
1011 				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1012 	len += input_print_modalias_bits(buf + len, size - len,
1013 				'r', id->relbit, 0, REL_MAX);
1014 	len += input_print_modalias_bits(buf + len, size - len,
1015 				'a', id->absbit, 0, ABS_MAX);
1016 	len += input_print_modalias_bits(buf + len, size - len,
1017 				'm', id->mscbit, 0, MSC_MAX);
1018 	len += input_print_modalias_bits(buf + len, size - len,
1019 				'l', id->ledbit, 0, LED_MAX);
1020 	len += input_print_modalias_bits(buf + len, size - len,
1021 				's', id->sndbit, 0, SND_MAX);
1022 	len += input_print_modalias_bits(buf + len, size - len,
1023 				'f', id->ffbit, 0, FF_MAX);
1024 	len += input_print_modalias_bits(buf + len, size - len,
1025 				'w', id->swbit, 0, SW_MAX);
1026 
1027 	if (add_cr)
1028 		len += snprintf(buf + len, max(size - len, 0), "\n");
1029 
1030 	return len;
1031 }
1032 
1033 static ssize_t input_dev_show_modalias(struct device *dev,
1034 				       struct device_attribute *attr,
1035 				       char *buf)
1036 {
1037 	struct input_dev *id = to_input_dev(dev);
1038 	ssize_t len;
1039 
1040 	len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1041 
1042 	return min_t(int, len, PAGE_SIZE);
1043 }
1044 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1045 
1046 static struct attribute *input_dev_attrs[] = {
1047 	&dev_attr_name.attr,
1048 	&dev_attr_phys.attr,
1049 	&dev_attr_uniq.attr,
1050 	&dev_attr_modalias.attr,
1051 	NULL
1052 };
1053 
1054 static struct attribute_group input_dev_attr_group = {
1055 	.attrs	= input_dev_attrs,
1056 };
1057 
1058 #define INPUT_DEV_ID_ATTR(name)						\
1059 static ssize_t input_dev_show_id_##name(struct device *dev,		\
1060 					struct device_attribute *attr,	\
1061 					char *buf)			\
1062 {									\
1063 	struct input_dev *input_dev = to_input_dev(dev);		\
1064 	return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name);	\
1065 }									\
1066 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1067 
1068 INPUT_DEV_ID_ATTR(bustype);
1069 INPUT_DEV_ID_ATTR(vendor);
1070 INPUT_DEV_ID_ATTR(product);
1071 INPUT_DEV_ID_ATTR(version);
1072 
1073 static struct attribute *input_dev_id_attrs[] = {
1074 	&dev_attr_bustype.attr,
1075 	&dev_attr_vendor.attr,
1076 	&dev_attr_product.attr,
1077 	&dev_attr_version.attr,
1078 	NULL
1079 };
1080 
1081 static struct attribute_group input_dev_id_attr_group = {
1082 	.name	= "id",
1083 	.attrs	= input_dev_id_attrs,
1084 };
1085 
1086 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1087 			      int max, int add_cr)
1088 {
1089 	int i;
1090 	int len = 0;
1091 
1092 	for (i = BITS_TO_LONGS(max) - 1; i > 0; i--)
1093 		if (bitmap[i])
1094 			break;
1095 
1096 	for (; i >= 0; i--)
1097 		len += snprintf(buf + len, max(buf_size - len, 0),
1098 				"%lx%s", bitmap[i], i > 0 ? " " : "");
1099 
1100 	if (add_cr)
1101 		len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1102 
1103 	return len;
1104 }
1105 
1106 #define INPUT_DEV_CAP_ATTR(ev, bm)					\
1107 static ssize_t input_dev_show_cap_##bm(struct device *dev,		\
1108 				       struct device_attribute *attr,	\
1109 				       char *buf)			\
1110 {									\
1111 	struct input_dev *input_dev = to_input_dev(dev);		\
1112 	int len = input_print_bitmap(buf, PAGE_SIZE,			\
1113 				     input_dev->bm##bit, ev##_MAX, 1);	\
1114 	return min_t(int, len, PAGE_SIZE);				\
1115 }									\
1116 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1117 
1118 INPUT_DEV_CAP_ATTR(EV, ev);
1119 INPUT_DEV_CAP_ATTR(KEY, key);
1120 INPUT_DEV_CAP_ATTR(REL, rel);
1121 INPUT_DEV_CAP_ATTR(ABS, abs);
1122 INPUT_DEV_CAP_ATTR(MSC, msc);
1123 INPUT_DEV_CAP_ATTR(LED, led);
1124 INPUT_DEV_CAP_ATTR(SND, snd);
1125 INPUT_DEV_CAP_ATTR(FF, ff);
1126 INPUT_DEV_CAP_ATTR(SW, sw);
1127 
1128 static struct attribute *input_dev_caps_attrs[] = {
1129 	&dev_attr_ev.attr,
1130 	&dev_attr_key.attr,
1131 	&dev_attr_rel.attr,
1132 	&dev_attr_abs.attr,
1133 	&dev_attr_msc.attr,
1134 	&dev_attr_led.attr,
1135 	&dev_attr_snd.attr,
1136 	&dev_attr_ff.attr,
1137 	&dev_attr_sw.attr,
1138 	NULL
1139 };
1140 
1141 static struct attribute_group input_dev_caps_attr_group = {
1142 	.name	= "capabilities",
1143 	.attrs	= input_dev_caps_attrs,
1144 };
1145 
1146 static struct attribute_group *input_dev_attr_groups[] = {
1147 	&input_dev_attr_group,
1148 	&input_dev_id_attr_group,
1149 	&input_dev_caps_attr_group,
1150 	NULL
1151 };
1152 
1153 static void input_dev_release(struct device *device)
1154 {
1155 	struct input_dev *dev = to_input_dev(device);
1156 
1157 	input_ff_destroy(dev);
1158 	kfree(dev);
1159 
1160 	module_put(THIS_MODULE);
1161 }
1162 
1163 /*
1164  * Input uevent interface - loading event handlers based on
1165  * device bitfields.
1166  */
1167 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1168 				   const char *name, unsigned long *bitmap, int max)
1169 {
1170 	int len;
1171 
1172 	if (add_uevent_var(env, "%s=", name))
1173 		return -ENOMEM;
1174 
1175 	len = input_print_bitmap(&env->buf[env->buflen - 1],
1176 				 sizeof(env->buf) - env->buflen,
1177 				 bitmap, max, 0);
1178 	if (len >= (sizeof(env->buf) - env->buflen))
1179 		return -ENOMEM;
1180 
1181 	env->buflen += len;
1182 	return 0;
1183 }
1184 
1185 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1186 					 struct input_dev *dev)
1187 {
1188 	int len;
1189 
1190 	if (add_uevent_var(env, "MODALIAS="))
1191 		return -ENOMEM;
1192 
1193 	len = input_print_modalias(&env->buf[env->buflen - 1],
1194 				   sizeof(env->buf) - env->buflen,
1195 				   dev, 0);
1196 	if (len >= (sizeof(env->buf) - env->buflen))
1197 		return -ENOMEM;
1198 
1199 	env->buflen += len;
1200 	return 0;
1201 }
1202 
1203 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
1204 	do {								\
1205 		int err = add_uevent_var(env, fmt, val);		\
1206 		if (err)						\
1207 			return err;					\
1208 	} while (0)
1209 
1210 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
1211 	do {								\
1212 		int err = input_add_uevent_bm_var(env, name, bm, max);	\
1213 		if (err)						\
1214 			return err;					\
1215 	} while (0)
1216 
1217 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
1218 	do {								\
1219 		int err = input_add_uevent_modalias_var(env, dev);	\
1220 		if (err)						\
1221 			return err;					\
1222 	} while (0)
1223 
1224 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1225 {
1226 	struct input_dev *dev = to_input_dev(device);
1227 
1228 	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1229 				dev->id.bustype, dev->id.vendor,
1230 				dev->id.product, dev->id.version);
1231 	if (dev->name)
1232 		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1233 	if (dev->phys)
1234 		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1235 	if (dev->uniq)
1236 		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1237 
1238 	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1239 	if (test_bit(EV_KEY, dev->evbit))
1240 		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1241 	if (test_bit(EV_REL, dev->evbit))
1242 		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1243 	if (test_bit(EV_ABS, dev->evbit))
1244 		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1245 	if (test_bit(EV_MSC, dev->evbit))
1246 		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1247 	if (test_bit(EV_LED, dev->evbit))
1248 		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1249 	if (test_bit(EV_SND, dev->evbit))
1250 		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1251 	if (test_bit(EV_FF, dev->evbit))
1252 		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1253 	if (test_bit(EV_SW, dev->evbit))
1254 		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1255 
1256 	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1257 
1258 	return 0;
1259 }
1260 
1261 static struct device_type input_dev_type = {
1262 	.groups		= input_dev_attr_groups,
1263 	.release	= input_dev_release,
1264 	.uevent		= input_dev_uevent,
1265 };
1266 
1267 struct class input_class = {
1268 	.name		= "input",
1269 };
1270 EXPORT_SYMBOL_GPL(input_class);
1271 
1272 /**
1273  * input_allocate_device - allocate memory for new input device
1274  *
1275  * Returns prepared struct input_dev or NULL.
1276  *
1277  * NOTE: Use input_free_device() to free devices that have not been
1278  * registered; input_unregister_device() should be used for already
1279  * registered devices.
1280  */
1281 struct input_dev *input_allocate_device(void)
1282 {
1283 	struct input_dev *dev;
1284 
1285 	dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
1286 	if (dev) {
1287 		dev->dev.type = &input_dev_type;
1288 		dev->dev.class = &input_class;
1289 		device_initialize(&dev->dev);
1290 		mutex_init(&dev->mutex);
1291 		spin_lock_init(&dev->event_lock);
1292 		INIT_LIST_HEAD(&dev->h_list);
1293 		INIT_LIST_HEAD(&dev->node);
1294 
1295 		__module_get(THIS_MODULE);
1296 	}
1297 
1298 	return dev;
1299 }
1300 EXPORT_SYMBOL(input_allocate_device);
1301 
1302 /**
1303  * input_free_device - free memory occupied by input_dev structure
1304  * @dev: input device to free
1305  *
1306  * This function should only be used if input_register_device()
1307  * was not called yet or if it failed. Once device was registered
1308  * use input_unregister_device() and memory will be freed once last
1309  * reference to the device is dropped.
1310  *
1311  * Device should be allocated by input_allocate_device().
1312  *
1313  * NOTE: If there are references to the input device then memory
1314  * will not be freed until last reference is dropped.
1315  */
1316 void input_free_device(struct input_dev *dev)
1317 {
1318 	if (dev)
1319 		input_put_device(dev);
1320 }
1321 EXPORT_SYMBOL(input_free_device);
1322 
1323 /**
1324  * input_set_capability - mark device as capable of a certain event
1325  * @dev: device that is capable of emitting or accepting event
1326  * @type: type of the event (EV_KEY, EV_REL, etc...)
1327  * @code: event code
1328  *
1329  * In addition to setting up corresponding bit in appropriate capability
1330  * bitmap the function also adjusts dev->evbit.
1331  */
1332 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1333 {
1334 	switch (type) {
1335 	case EV_KEY:
1336 		__set_bit(code, dev->keybit);
1337 		break;
1338 
1339 	case EV_REL:
1340 		__set_bit(code, dev->relbit);
1341 		break;
1342 
1343 	case EV_ABS:
1344 		__set_bit(code, dev->absbit);
1345 		break;
1346 
1347 	case EV_MSC:
1348 		__set_bit(code, dev->mscbit);
1349 		break;
1350 
1351 	case EV_SW:
1352 		__set_bit(code, dev->swbit);
1353 		break;
1354 
1355 	case EV_LED:
1356 		__set_bit(code, dev->ledbit);
1357 		break;
1358 
1359 	case EV_SND:
1360 		__set_bit(code, dev->sndbit);
1361 		break;
1362 
1363 	case EV_FF:
1364 		__set_bit(code, dev->ffbit);
1365 		break;
1366 
1367 	case EV_PWR:
1368 		/* do nothing */
1369 		break;
1370 
1371 	default:
1372 		printk(KERN_ERR
1373 			"input_set_capability: unknown type %u (code %u)\n",
1374 			type, code);
1375 		dump_stack();
1376 		return;
1377 	}
1378 
1379 	__set_bit(type, dev->evbit);
1380 }
1381 EXPORT_SYMBOL(input_set_capability);
1382 
1383 /**
1384  * input_register_device - register device with input core
1385  * @dev: device to be registered
1386  *
1387  * This function registers device with input core. The device must be
1388  * allocated with input_allocate_device() and all it's capabilities
1389  * set up before registering.
1390  * If function fails the device must be freed with input_free_device().
1391  * Once device has been successfully registered it can be unregistered
1392  * with input_unregister_device(); input_free_device() should not be
1393  * called in this case.
1394  */
1395 int input_register_device(struct input_dev *dev)
1396 {
1397 	static atomic_t input_no = ATOMIC_INIT(0);
1398 	struct input_handler *handler;
1399 	const char *path;
1400 	int error;
1401 
1402 	__set_bit(EV_SYN, dev->evbit);
1403 
1404 	/*
1405 	 * If delay and period are pre-set by the driver, then autorepeating
1406 	 * is handled by the driver itself and we don't do it in input.c.
1407 	 */
1408 
1409 	init_timer(&dev->timer);
1410 	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
1411 		dev->timer.data = (long) dev;
1412 		dev->timer.function = input_repeat_key;
1413 		dev->rep[REP_DELAY] = 250;
1414 		dev->rep[REP_PERIOD] = 33;
1415 	}
1416 
1417 	if (!dev->getkeycode)
1418 		dev->getkeycode = input_default_getkeycode;
1419 
1420 	if (!dev->setkeycode)
1421 		dev->setkeycode = input_default_setkeycode;
1422 
1423 	dev_set_name(&dev->dev, "input%ld",
1424 		     (unsigned long) atomic_inc_return(&input_no) - 1);
1425 
1426 	error = device_add(&dev->dev);
1427 	if (error)
1428 		return error;
1429 
1430 	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1431 	printk(KERN_INFO "input: %s as %s\n",
1432 		dev->name ? dev->name : "Unspecified device", path ? path : "N/A");
1433 	kfree(path);
1434 
1435 	error = mutex_lock_interruptible(&input_mutex);
1436 	if (error) {
1437 		device_del(&dev->dev);
1438 		return error;
1439 	}
1440 
1441 	list_add_tail(&dev->node, &input_dev_list);
1442 
1443 	list_for_each_entry(handler, &input_handler_list, node)
1444 		input_attach_handler(dev, handler);
1445 
1446 	input_wakeup_procfs_readers();
1447 
1448 	mutex_unlock(&input_mutex);
1449 
1450 	return 0;
1451 }
1452 EXPORT_SYMBOL(input_register_device);
1453 
1454 /**
1455  * input_unregister_device - unregister previously registered device
1456  * @dev: device to be unregistered
1457  *
1458  * This function unregisters an input device. Once device is unregistered
1459  * the caller should not try to access it as it may get freed at any moment.
1460  */
1461 void input_unregister_device(struct input_dev *dev)
1462 {
1463 	struct input_handle *handle, *next;
1464 
1465 	input_disconnect_device(dev);
1466 
1467 	mutex_lock(&input_mutex);
1468 
1469 	list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
1470 		handle->handler->disconnect(handle);
1471 	WARN_ON(!list_empty(&dev->h_list));
1472 
1473 	del_timer_sync(&dev->timer);
1474 	list_del_init(&dev->node);
1475 
1476 	input_wakeup_procfs_readers();
1477 
1478 	mutex_unlock(&input_mutex);
1479 
1480 	device_unregister(&dev->dev);
1481 }
1482 EXPORT_SYMBOL(input_unregister_device);
1483 
1484 /**
1485  * input_register_handler - register a new input handler
1486  * @handler: handler to be registered
1487  *
1488  * This function registers a new input handler (interface) for input
1489  * devices in the system and attaches it to all input devices that
1490  * are compatible with the handler.
1491  */
1492 int input_register_handler(struct input_handler *handler)
1493 {
1494 	struct input_dev *dev;
1495 	int retval;
1496 
1497 	retval = mutex_lock_interruptible(&input_mutex);
1498 	if (retval)
1499 		return retval;
1500 
1501 	INIT_LIST_HEAD(&handler->h_list);
1502 
1503 	if (handler->fops != NULL) {
1504 		if (input_table[handler->minor >> 5]) {
1505 			retval = -EBUSY;
1506 			goto out;
1507 		}
1508 		input_table[handler->minor >> 5] = handler;
1509 	}
1510 
1511 	list_add_tail(&handler->node, &input_handler_list);
1512 
1513 	list_for_each_entry(dev, &input_dev_list, node)
1514 		input_attach_handler(dev, handler);
1515 
1516 	input_wakeup_procfs_readers();
1517 
1518  out:
1519 	mutex_unlock(&input_mutex);
1520 	return retval;
1521 }
1522 EXPORT_SYMBOL(input_register_handler);
1523 
1524 /**
1525  * input_unregister_handler - unregisters an input handler
1526  * @handler: handler to be unregistered
1527  *
1528  * This function disconnects a handler from its input devices and
1529  * removes it from lists of known handlers.
1530  */
1531 void input_unregister_handler(struct input_handler *handler)
1532 {
1533 	struct input_handle *handle, *next;
1534 
1535 	mutex_lock(&input_mutex);
1536 
1537 	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
1538 		handler->disconnect(handle);
1539 	WARN_ON(!list_empty(&handler->h_list));
1540 
1541 	list_del_init(&handler->node);
1542 
1543 	if (handler->fops != NULL)
1544 		input_table[handler->minor >> 5] = NULL;
1545 
1546 	input_wakeup_procfs_readers();
1547 
1548 	mutex_unlock(&input_mutex);
1549 }
1550 EXPORT_SYMBOL(input_unregister_handler);
1551 
1552 /**
1553  * input_register_handle - register a new input handle
1554  * @handle: handle to register
1555  *
1556  * This function puts a new input handle onto device's
1557  * and handler's lists so that events can flow through
1558  * it once it is opened using input_open_device().
1559  *
1560  * This function is supposed to be called from handler's
1561  * connect() method.
1562  */
1563 int input_register_handle(struct input_handle *handle)
1564 {
1565 	struct input_handler *handler = handle->handler;
1566 	struct input_dev *dev = handle->dev;
1567 	int error;
1568 
1569 	/*
1570 	 * We take dev->mutex here to prevent race with
1571 	 * input_release_device().
1572 	 */
1573 	error = mutex_lock_interruptible(&dev->mutex);
1574 	if (error)
1575 		return error;
1576 	list_add_tail_rcu(&handle->d_node, &dev->h_list);
1577 	mutex_unlock(&dev->mutex);
1578 
1579 	/*
1580 	 * Since we are supposed to be called from ->connect()
1581 	 * which is mutually exclusive with ->disconnect()
1582 	 * we can't be racing with input_unregister_handle()
1583 	 * and so separate lock is not needed here.
1584 	 */
1585 	list_add_tail(&handle->h_node, &handler->h_list);
1586 
1587 	if (handler->start)
1588 		handler->start(handle);
1589 
1590 	return 0;
1591 }
1592 EXPORT_SYMBOL(input_register_handle);
1593 
1594 /**
1595  * input_unregister_handle - unregister an input handle
1596  * @handle: handle to unregister
1597  *
1598  * This function removes input handle from device's
1599  * and handler's lists.
1600  *
1601  * This function is supposed to be called from handler's
1602  * disconnect() method.
1603  */
1604 void input_unregister_handle(struct input_handle *handle)
1605 {
1606 	struct input_dev *dev = handle->dev;
1607 
1608 	list_del_init(&handle->h_node);
1609 
1610 	/*
1611 	 * Take dev->mutex to prevent race with input_release_device().
1612 	 */
1613 	mutex_lock(&dev->mutex);
1614 	list_del_rcu(&handle->d_node);
1615 	mutex_unlock(&dev->mutex);
1616 	synchronize_rcu();
1617 }
1618 EXPORT_SYMBOL(input_unregister_handle);
1619 
1620 static int input_open_file(struct inode *inode, struct file *file)
1621 {
1622 	struct input_handler *handler;
1623 	const struct file_operations *old_fops, *new_fops = NULL;
1624 	int err;
1625 
1626 	lock_kernel();
1627 	/* No load-on-demand here? */
1628 	handler = input_table[iminor(inode) >> 5];
1629 	if (!handler || !(new_fops = fops_get(handler->fops))) {
1630 		err = -ENODEV;
1631 		goto out;
1632 	}
1633 
1634 	/*
1635 	 * That's _really_ odd. Usually NULL ->open means "nothing special",
1636 	 * not "no device". Oh, well...
1637 	 */
1638 	if (!new_fops->open) {
1639 		fops_put(new_fops);
1640 		err = -ENODEV;
1641 		goto out;
1642 	}
1643 	old_fops = file->f_op;
1644 	file->f_op = new_fops;
1645 
1646 	err = new_fops->open(inode, file);
1647 
1648 	if (err) {
1649 		fops_put(file->f_op);
1650 		file->f_op = fops_get(old_fops);
1651 	}
1652 	fops_put(old_fops);
1653 out:
1654 	unlock_kernel();
1655 	return err;
1656 }
1657 
1658 static const struct file_operations input_fops = {
1659 	.owner = THIS_MODULE,
1660 	.open = input_open_file,
1661 };
1662 
1663 static void __init input_init_abs_bypass(void)
1664 {
1665 	const unsigned int *p;
1666 
1667 	for (p = input_abs_bypass_init_data; *p; p++)
1668 		input_abs_bypass[BIT_WORD(*p)] |= BIT_MASK(*p);
1669 }
1670 
1671 static int __init input_init(void)
1672 {
1673 	int err;
1674 
1675 	input_init_abs_bypass();
1676 
1677 	err = class_register(&input_class);
1678 	if (err) {
1679 		printk(KERN_ERR "input: unable to register input_dev class\n");
1680 		return err;
1681 	}
1682 
1683 	err = input_proc_init();
1684 	if (err)
1685 		goto fail1;
1686 
1687 	err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
1688 	if (err) {
1689 		printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
1690 		goto fail2;
1691 	}
1692 
1693 	return 0;
1694 
1695  fail2:	input_proc_exit();
1696  fail1:	class_unregister(&input_class);
1697 	return err;
1698 }
1699 
1700 static void __exit input_exit(void)
1701 {
1702 	input_proc_exit();
1703 	unregister_chrdev(INPUT_MAJOR, "input");
1704 	class_unregister(&input_class);
1705 }
1706 
1707 subsys_initcall(input_init);
1708 module_exit(input_exit);
1709