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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * The input core
4  *
5  * Copyright (c) 1999-2002 Vojtech Pavlik
6  */
7 
8 
9 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
10 
11 #include <linux/init.h>
12 #include <linux/types.h>
13 #include <linux/idr.h>
14 #include <linux/input/mt.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/random.h>
18 #include <linux/major.h>
19 #include <linux/proc_fs.h>
20 #include <linux/sched.h>
21 #include <linux/seq_file.h>
22 #include <linux/poll.h>
23 #include <linux/device.h>
24 #include <linux/mutex.h>
25 #include <linux/rcupdate.h>
26 #include "input-compat.h"
27 #include "input-poller.h"
28 
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
30 MODULE_DESCRIPTION("Input core");
31 MODULE_LICENSE("GPL");
32 
33 #define INPUT_MAX_CHAR_DEVICES		1024
34 #define INPUT_FIRST_DYNAMIC_DEV		256
35 static DEFINE_IDA(input_ida);
36 
37 static LIST_HEAD(input_dev_list);
38 static LIST_HEAD(input_handler_list);
39 
40 /*
41  * input_mutex protects access to both input_dev_list and input_handler_list.
42  * This also causes input_[un]register_device and input_[un]register_handler
43  * be mutually exclusive which simplifies locking in drivers implementing
44  * input handlers.
45  */
46 static DEFINE_MUTEX(input_mutex);
47 
48 static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
49 
is_event_supported(unsigned int code,unsigned long * bm,unsigned int max)50 static inline int is_event_supported(unsigned int code,
51 				     unsigned long *bm, unsigned int max)
52 {
53 	return code <= max && test_bit(code, bm);
54 }
55 
input_defuzz_abs_event(int value,int old_val,int fuzz)56 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
57 {
58 	if (fuzz) {
59 		if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
60 			return old_val;
61 
62 		if (value > old_val - fuzz && value < old_val + fuzz)
63 			return (old_val * 3 + value) / 4;
64 
65 		if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
66 			return (old_val + value) / 2;
67 	}
68 
69 	return value;
70 }
71 
input_start_autorepeat(struct input_dev * dev,int code)72 static void input_start_autorepeat(struct input_dev *dev, int code)
73 {
74 	if (test_bit(EV_REP, dev->evbit) &&
75 	    dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
76 	    dev->timer.function) {
77 		dev->repeat_key = code;
78 		mod_timer(&dev->timer,
79 			  jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
80 	}
81 }
82 
input_stop_autorepeat(struct input_dev * dev)83 static void input_stop_autorepeat(struct input_dev *dev)
84 {
85 	del_timer(&dev->timer);
86 }
87 
88 /*
89  * Pass event first through all filters and then, if event has not been
90  * filtered out, through all open handles. This function is called with
91  * dev->event_lock held and interrupts disabled.
92  */
input_to_handler(struct input_handle * handle,struct input_value * vals,unsigned int count)93 static unsigned int input_to_handler(struct input_handle *handle,
94 			struct input_value *vals, unsigned int count)
95 {
96 	struct input_handler *handler = handle->handler;
97 	struct input_value *end = vals;
98 	struct input_value *v;
99 
100 	if (handler->filter) {
101 		for (v = vals; v != vals + count; v++) {
102 			if (handler->filter(handle, v->type, v->code, v->value))
103 				continue;
104 			if (end != v)
105 				*end = *v;
106 			end++;
107 		}
108 		count = end - vals;
109 	}
110 
111 	if (!count)
112 		return 0;
113 
114 	if (handler->events)
115 		handler->events(handle, vals, count);
116 	else if (handler->event)
117 		for (v = vals; v != vals + count; v++)
118 			handler->event(handle, v->type, v->code, v->value);
119 
120 	return count;
121 }
122 
123 /*
124  * Pass values first through all filters and then, if event has not been
125  * filtered out, through all open handles. This function is called with
126  * dev->event_lock held and interrupts disabled.
127  */
input_pass_values(struct input_dev * dev,struct input_value * vals,unsigned int count)128 static void input_pass_values(struct input_dev *dev,
129 			      struct input_value *vals, unsigned int count)
130 {
131 	struct input_handle *handle;
132 	struct input_value *v;
133 
134 	if (!count)
135 		return;
136 
137 	rcu_read_lock();
138 
139 	handle = rcu_dereference(dev->grab);
140 	if (handle) {
141 		count = input_to_handler(handle, vals, count);
142 	} else {
143 		list_for_each_entry_rcu(handle, &dev->h_list, d_node)
144 			if (handle->open) {
145 				count = input_to_handler(handle, vals, count);
146 				if (!count)
147 					break;
148 			}
149 	}
150 
151 	rcu_read_unlock();
152 
153 	/* trigger auto repeat for key events */
154 	if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
155 		for (v = vals; v != vals + count; v++) {
156 			if (v->type == EV_KEY && v->value != 2) {
157 				if (v->value)
158 					input_start_autorepeat(dev, v->code);
159 				else
160 					input_stop_autorepeat(dev);
161 			}
162 		}
163 	}
164 }
165 
input_pass_event(struct input_dev * dev,unsigned int type,unsigned int code,int value)166 static void input_pass_event(struct input_dev *dev,
167 			     unsigned int type, unsigned int code, int value)
168 {
169 	struct input_value vals[] = { { type, code, value } };
170 
171 	input_pass_values(dev, vals, ARRAY_SIZE(vals));
172 }
173 
174 /*
175  * Generate software autorepeat event. Note that we take
176  * dev->event_lock here to avoid racing with input_event
177  * which may cause keys get "stuck".
178  */
input_repeat_key(struct timer_list * t)179 static void input_repeat_key(struct timer_list *t)
180 {
181 	struct input_dev *dev = from_timer(dev, t, timer);
182 	unsigned long flags;
183 
184 	spin_lock_irqsave(&dev->event_lock, flags);
185 
186 	if (test_bit(dev->repeat_key, dev->key) &&
187 	    is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
188 		struct input_value vals[] =  {
189 			{ EV_KEY, dev->repeat_key, 2 },
190 			input_value_sync
191 		};
192 
193 		input_pass_values(dev, vals, ARRAY_SIZE(vals));
194 
195 		if (dev->rep[REP_PERIOD])
196 			mod_timer(&dev->timer, jiffies +
197 					msecs_to_jiffies(dev->rep[REP_PERIOD]));
198 	}
199 
200 	spin_unlock_irqrestore(&dev->event_lock, flags);
201 }
202 
203 #define INPUT_IGNORE_EVENT	0
204 #define INPUT_PASS_TO_HANDLERS	1
205 #define INPUT_PASS_TO_DEVICE	2
206 #define INPUT_SLOT		4
207 #define INPUT_FLUSH		8
208 #define INPUT_PASS_TO_ALL	(INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
209 
input_handle_abs_event(struct input_dev * dev,unsigned int code,int * pval)210 static int input_handle_abs_event(struct input_dev *dev,
211 				  unsigned int code, int *pval)
212 {
213 	struct input_mt *mt = dev->mt;
214 	bool is_mt_event;
215 	int *pold;
216 
217 	if (code == ABS_MT_SLOT) {
218 		/*
219 		 * "Stage" the event; we'll flush it later, when we
220 		 * get actual touch data.
221 		 */
222 		if (mt && *pval >= 0 && *pval < mt->num_slots)
223 			mt->slot = *pval;
224 
225 		return INPUT_IGNORE_EVENT;
226 	}
227 
228 	is_mt_event = input_is_mt_value(code);
229 
230 	if (!is_mt_event) {
231 		pold = &dev->absinfo[code].value;
232 	} else if (mt) {
233 		pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
234 	} else {
235 		/*
236 		 * Bypass filtering for multi-touch events when
237 		 * not employing slots.
238 		 */
239 		pold = NULL;
240 	}
241 
242 	if (pold) {
243 		*pval = input_defuzz_abs_event(*pval, *pold,
244 						dev->absinfo[code].fuzz);
245 		if (*pold == *pval)
246 			return INPUT_IGNORE_EVENT;
247 
248 		*pold = *pval;
249 	}
250 
251 	/* Flush pending "slot" event */
252 	if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
253 		input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
254 		return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
255 	}
256 
257 	return INPUT_PASS_TO_HANDLERS;
258 }
259 
input_get_disposition(struct input_dev * dev,unsigned int type,unsigned int code,int * pval)260 static int input_get_disposition(struct input_dev *dev,
261 			  unsigned int type, unsigned int code, int *pval)
262 {
263 	int disposition = INPUT_IGNORE_EVENT;
264 	int value = *pval;
265 
266 	switch (type) {
267 
268 	case EV_SYN:
269 		switch (code) {
270 		case SYN_CONFIG:
271 			disposition = INPUT_PASS_TO_ALL;
272 			break;
273 
274 		case SYN_REPORT:
275 			disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
276 			break;
277 		case SYN_MT_REPORT:
278 			disposition = INPUT_PASS_TO_HANDLERS;
279 			break;
280 		}
281 		break;
282 
283 	case EV_KEY:
284 		if (is_event_supported(code, dev->keybit, KEY_MAX)) {
285 
286 			/* auto-repeat bypasses state updates */
287 			if (value == 2) {
288 				disposition = INPUT_PASS_TO_HANDLERS;
289 				break;
290 			}
291 
292 			if (!!test_bit(code, dev->key) != !!value) {
293 
294 				__change_bit(code, dev->key);
295 				disposition = INPUT_PASS_TO_HANDLERS;
296 			}
297 		}
298 		break;
299 
300 	case EV_SW:
301 		if (is_event_supported(code, dev->swbit, SW_MAX) &&
302 		    !!test_bit(code, dev->sw) != !!value) {
303 
304 			__change_bit(code, dev->sw);
305 			disposition = INPUT_PASS_TO_HANDLERS;
306 		}
307 		break;
308 
309 	case EV_ABS:
310 		if (is_event_supported(code, dev->absbit, ABS_MAX))
311 			disposition = input_handle_abs_event(dev, code, &value);
312 
313 		break;
314 
315 	case EV_REL:
316 		if (is_event_supported(code, dev->relbit, REL_MAX) && value)
317 			disposition = INPUT_PASS_TO_HANDLERS;
318 
319 		break;
320 
321 	case EV_MSC:
322 		if (is_event_supported(code, dev->mscbit, MSC_MAX))
323 			disposition = INPUT_PASS_TO_ALL;
324 
325 		break;
326 
327 	case EV_LED:
328 		if (is_event_supported(code, dev->ledbit, LED_MAX) &&
329 		    !!test_bit(code, dev->led) != !!value) {
330 
331 			__change_bit(code, dev->led);
332 			disposition = INPUT_PASS_TO_ALL;
333 		}
334 		break;
335 
336 	case EV_SND:
337 		if (is_event_supported(code, dev->sndbit, SND_MAX)) {
338 
339 			if (!!test_bit(code, dev->snd) != !!value)
340 				__change_bit(code, dev->snd);
341 			disposition = INPUT_PASS_TO_ALL;
342 		}
343 		break;
344 
345 	case EV_REP:
346 		if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
347 			dev->rep[code] = value;
348 			disposition = INPUT_PASS_TO_ALL;
349 		}
350 		break;
351 
352 	case EV_FF:
353 		if (value >= 0)
354 			disposition = INPUT_PASS_TO_ALL;
355 		break;
356 
357 	case EV_PWR:
358 		disposition = INPUT_PASS_TO_ALL;
359 		break;
360 	}
361 
362 	*pval = value;
363 	return disposition;
364 }
365 
input_handle_event(struct input_dev * dev,unsigned int type,unsigned int code,int value)366 static void input_handle_event(struct input_dev *dev,
367 			       unsigned int type, unsigned int code, int value)
368 {
369 	int disposition = input_get_disposition(dev, type, code, &value);
370 
371 	if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
372 		add_input_randomness(type, code, value);
373 
374 	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
375 		dev->event(dev, type, code, value);
376 
377 	if (!dev->vals)
378 		return;
379 
380 	if (disposition & INPUT_PASS_TO_HANDLERS) {
381 		struct input_value *v;
382 
383 		if (disposition & INPUT_SLOT) {
384 			v = &dev->vals[dev->num_vals++];
385 			v->type = EV_ABS;
386 			v->code = ABS_MT_SLOT;
387 			v->value = dev->mt->slot;
388 		}
389 
390 		v = &dev->vals[dev->num_vals++];
391 		v->type = type;
392 		v->code = code;
393 		v->value = value;
394 	}
395 
396 	if (disposition & INPUT_FLUSH) {
397 		if (dev->num_vals >= 2)
398 			input_pass_values(dev, dev->vals, dev->num_vals);
399 		dev->num_vals = 0;
400 		/*
401 		 * Reset the timestamp on flush so we won't end up
402 		 * with a stale one. Note we only need to reset the
403 		 * monolithic one as we use its presence when deciding
404 		 * whether to generate a synthetic timestamp.
405 		 */
406 		dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
407 	} else if (dev->num_vals >= dev->max_vals - 2) {
408 		dev->vals[dev->num_vals++] = input_value_sync;
409 		input_pass_values(dev, dev->vals, dev->num_vals);
410 		dev->num_vals = 0;
411 	}
412 
413 }
414 
415 /**
416  * input_event() - report new input event
417  * @dev: device that generated the event
418  * @type: type of the event
419  * @code: event code
420  * @value: value of the event
421  *
422  * This function should be used by drivers implementing various input
423  * devices to report input events. See also input_inject_event().
424  *
425  * NOTE: input_event() may be safely used right after input device was
426  * allocated with input_allocate_device(), even before it is registered
427  * with input_register_device(), but the event will not reach any of the
428  * input handlers. Such early invocation of input_event() may be used
429  * to 'seed' initial state of a switch or initial position of absolute
430  * axis, etc.
431  */
input_event(struct input_dev * dev,unsigned int type,unsigned int code,int value)432 void input_event(struct input_dev *dev,
433 		 unsigned int type, unsigned int code, int value)
434 {
435 	unsigned long flags;
436 
437 	if (is_event_supported(type, dev->evbit, EV_MAX)) {
438 
439 		spin_lock_irqsave(&dev->event_lock, flags);
440 		input_handle_event(dev, type, code, value);
441 		spin_unlock_irqrestore(&dev->event_lock, flags);
442 	}
443 }
444 EXPORT_SYMBOL(input_event);
445 
446 /**
447  * input_inject_event() - send input event from input handler
448  * @handle: input handle to send event through
449  * @type: type of the event
450  * @code: event code
451  * @value: value of the event
452  *
453  * Similar to input_event() but will ignore event if device is
454  * "grabbed" and handle injecting event is not the one that owns
455  * the device.
456  */
input_inject_event(struct input_handle * handle,unsigned int type,unsigned int code,int value)457 void input_inject_event(struct input_handle *handle,
458 			unsigned int type, unsigned int code, int value)
459 {
460 	struct input_dev *dev = handle->dev;
461 	struct input_handle *grab;
462 	unsigned long flags;
463 
464 	if (is_event_supported(type, dev->evbit, EV_MAX)) {
465 		spin_lock_irqsave(&dev->event_lock, flags);
466 
467 		rcu_read_lock();
468 		grab = rcu_dereference(dev->grab);
469 		if (!grab || grab == handle)
470 			input_handle_event(dev, type, code, value);
471 		rcu_read_unlock();
472 
473 		spin_unlock_irqrestore(&dev->event_lock, flags);
474 	}
475 }
476 EXPORT_SYMBOL(input_inject_event);
477 
478 /**
479  * input_alloc_absinfo - allocates array of input_absinfo structs
480  * @dev: the input device emitting absolute events
481  *
482  * If the absinfo struct the caller asked for is already allocated, this
483  * functions will not do anything.
484  */
input_alloc_absinfo(struct input_dev * dev)485 void input_alloc_absinfo(struct input_dev *dev)
486 {
487 	if (dev->absinfo)
488 		return;
489 
490 	dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
491 	if (!dev->absinfo) {
492 		dev_err(dev->dev.parent ?: &dev->dev,
493 			"%s: unable to allocate memory\n", __func__);
494 		/*
495 		 * We will handle this allocation failure in
496 		 * input_register_device() when we refuse to register input
497 		 * device with ABS bits but without absinfo.
498 		 */
499 	}
500 }
501 EXPORT_SYMBOL(input_alloc_absinfo);
502 
input_set_abs_params(struct input_dev * dev,unsigned int axis,int min,int max,int fuzz,int flat)503 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
504 			  int min, int max, int fuzz, int flat)
505 {
506 	struct input_absinfo *absinfo;
507 
508 	input_alloc_absinfo(dev);
509 	if (!dev->absinfo)
510 		return;
511 
512 	absinfo = &dev->absinfo[axis];
513 	absinfo->minimum = min;
514 	absinfo->maximum = max;
515 	absinfo->fuzz = fuzz;
516 	absinfo->flat = flat;
517 
518 	__set_bit(EV_ABS, dev->evbit);
519 	__set_bit(axis, dev->absbit);
520 }
521 EXPORT_SYMBOL(input_set_abs_params);
522 
523 
524 /**
525  * input_grab_device - grabs device for exclusive use
526  * @handle: input handle that wants to own the device
527  *
528  * When a device is grabbed by an input handle all events generated by
529  * the device are delivered only to this handle. Also events injected
530  * by other input handles are ignored while device is grabbed.
531  */
input_grab_device(struct input_handle * handle)532 int input_grab_device(struct input_handle *handle)
533 {
534 	struct input_dev *dev = handle->dev;
535 	int retval;
536 
537 	retval = mutex_lock_interruptible(&dev->mutex);
538 	if (retval)
539 		return retval;
540 
541 	if (dev->grab) {
542 		retval = -EBUSY;
543 		goto out;
544 	}
545 
546 	rcu_assign_pointer(dev->grab, handle);
547 
548  out:
549 	mutex_unlock(&dev->mutex);
550 	return retval;
551 }
552 EXPORT_SYMBOL(input_grab_device);
553 
__input_release_device(struct input_handle * handle)554 static void __input_release_device(struct input_handle *handle)
555 {
556 	struct input_dev *dev = handle->dev;
557 	struct input_handle *grabber;
558 
559 	grabber = rcu_dereference_protected(dev->grab,
560 					    lockdep_is_held(&dev->mutex));
561 	if (grabber == handle) {
562 		rcu_assign_pointer(dev->grab, NULL);
563 		/* Make sure input_pass_event() notices that grab is gone */
564 		synchronize_rcu();
565 
566 		list_for_each_entry(handle, &dev->h_list, d_node)
567 			if (handle->open && handle->handler->start)
568 				handle->handler->start(handle);
569 	}
570 }
571 
572 /**
573  * input_release_device - release previously grabbed device
574  * @handle: input handle that owns the device
575  *
576  * Releases previously grabbed device so that other input handles can
577  * start receiving input events. Upon release all handlers attached
578  * to the device have their start() method called so they have a change
579  * to synchronize device state with the rest of the system.
580  */
input_release_device(struct input_handle * handle)581 void input_release_device(struct input_handle *handle)
582 {
583 	struct input_dev *dev = handle->dev;
584 
585 	mutex_lock(&dev->mutex);
586 	__input_release_device(handle);
587 	mutex_unlock(&dev->mutex);
588 }
589 EXPORT_SYMBOL(input_release_device);
590 
591 /**
592  * input_open_device - open input device
593  * @handle: handle through which device is being accessed
594  *
595  * This function should be called by input handlers when they
596  * want to start receive events from given input device.
597  */
input_open_device(struct input_handle * handle)598 int input_open_device(struct input_handle *handle)
599 {
600 	struct input_dev *dev = handle->dev;
601 	int retval;
602 
603 	retval = mutex_lock_interruptible(&dev->mutex);
604 	if (retval)
605 		return retval;
606 
607 	if (dev->going_away) {
608 		retval = -ENODEV;
609 		goto out;
610 	}
611 
612 	handle->open++;
613 
614 	if (dev->users++) {
615 		/*
616 		 * Device is already opened, so we can exit immediately and
617 		 * report success.
618 		 */
619 		goto out;
620 	}
621 
622 	if (dev->open) {
623 		retval = dev->open(dev);
624 		if (retval) {
625 			dev->users--;
626 			handle->open--;
627 			/*
628 			 * Make sure we are not delivering any more events
629 			 * through this handle
630 			 */
631 			synchronize_rcu();
632 			goto out;
633 		}
634 	}
635 
636 	if (dev->poller)
637 		input_dev_poller_start(dev->poller);
638 
639  out:
640 	mutex_unlock(&dev->mutex);
641 	return retval;
642 }
643 EXPORT_SYMBOL(input_open_device);
644 
input_flush_device(struct input_handle * handle,struct file * file)645 int input_flush_device(struct input_handle *handle, struct file *file)
646 {
647 	struct input_dev *dev = handle->dev;
648 	int retval;
649 
650 	retval = mutex_lock_interruptible(&dev->mutex);
651 	if (retval)
652 		return retval;
653 
654 	if (dev->flush)
655 		retval = dev->flush(dev, file);
656 
657 	mutex_unlock(&dev->mutex);
658 	return retval;
659 }
660 EXPORT_SYMBOL(input_flush_device);
661 
662 /**
663  * input_close_device - close input device
664  * @handle: handle through which device is being accessed
665  *
666  * This function should be called by input handlers when they
667  * want to stop receive events from given input device.
668  */
input_close_device(struct input_handle * handle)669 void input_close_device(struct input_handle *handle)
670 {
671 	struct input_dev *dev = handle->dev;
672 
673 	mutex_lock(&dev->mutex);
674 
675 	__input_release_device(handle);
676 
677 	if (!--dev->users) {
678 		if (dev->poller)
679 			input_dev_poller_stop(dev->poller);
680 
681 		if (dev->close)
682 			dev->close(dev);
683 	}
684 
685 	if (!--handle->open) {
686 		/*
687 		 * synchronize_rcu() makes sure that input_pass_event()
688 		 * completed and that no more input events are delivered
689 		 * through this handle
690 		 */
691 		synchronize_rcu();
692 	}
693 
694 	mutex_unlock(&dev->mutex);
695 }
696 EXPORT_SYMBOL(input_close_device);
697 
698 /*
699  * Simulate keyup events for all keys that are marked as pressed.
700  * The function must be called with dev->event_lock held.
701  */
input_dev_release_keys(struct input_dev * dev)702 static void input_dev_release_keys(struct input_dev *dev)
703 {
704 	bool need_sync = false;
705 	int code;
706 
707 	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
708 		for_each_set_bit(code, dev->key, KEY_CNT) {
709 			input_pass_event(dev, EV_KEY, code, 0);
710 			need_sync = true;
711 		}
712 
713 		if (need_sync)
714 			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
715 
716 		memset(dev->key, 0, sizeof(dev->key));
717 	}
718 }
719 
720 /*
721  * Prepare device for unregistering
722  */
input_disconnect_device(struct input_dev * dev)723 static void input_disconnect_device(struct input_dev *dev)
724 {
725 	struct input_handle *handle;
726 
727 	/*
728 	 * Mark device as going away. Note that we take dev->mutex here
729 	 * not to protect access to dev->going_away but rather to ensure
730 	 * that there are no threads in the middle of input_open_device()
731 	 */
732 	mutex_lock(&dev->mutex);
733 	dev->going_away = true;
734 	mutex_unlock(&dev->mutex);
735 
736 	spin_lock_irq(&dev->event_lock);
737 
738 	/*
739 	 * Simulate keyup events for all pressed keys so that handlers
740 	 * are not left with "stuck" keys. The driver may continue
741 	 * generate events even after we done here but they will not
742 	 * reach any handlers.
743 	 */
744 	input_dev_release_keys(dev);
745 
746 	list_for_each_entry(handle, &dev->h_list, d_node)
747 		handle->open = 0;
748 
749 	spin_unlock_irq(&dev->event_lock);
750 }
751 
752 /**
753  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
754  * @ke: keymap entry containing scancode to be converted.
755  * @scancode: pointer to the location where converted scancode should
756  *	be stored.
757  *
758  * This function is used to convert scancode stored in &struct keymap_entry
759  * into scalar form understood by legacy keymap handling methods. These
760  * methods expect scancodes to be represented as 'unsigned int'.
761  */
input_scancode_to_scalar(const struct input_keymap_entry * ke,unsigned int * scancode)762 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
763 			     unsigned int *scancode)
764 {
765 	switch (ke->len) {
766 	case 1:
767 		*scancode = *((u8 *)ke->scancode);
768 		break;
769 
770 	case 2:
771 		*scancode = *((u16 *)ke->scancode);
772 		break;
773 
774 	case 4:
775 		*scancode = *((u32 *)ke->scancode);
776 		break;
777 
778 	default:
779 		return -EINVAL;
780 	}
781 
782 	return 0;
783 }
784 EXPORT_SYMBOL(input_scancode_to_scalar);
785 
786 /*
787  * Those routines handle the default case where no [gs]etkeycode() is
788  * defined. In this case, an array indexed by the scancode is used.
789  */
790 
input_fetch_keycode(struct input_dev * dev,unsigned int index)791 static unsigned int input_fetch_keycode(struct input_dev *dev,
792 					unsigned int index)
793 {
794 	switch (dev->keycodesize) {
795 	case 1:
796 		return ((u8 *)dev->keycode)[index];
797 
798 	case 2:
799 		return ((u16 *)dev->keycode)[index];
800 
801 	default:
802 		return ((u32 *)dev->keycode)[index];
803 	}
804 }
805 
input_default_getkeycode(struct input_dev * dev,struct input_keymap_entry * ke)806 static int input_default_getkeycode(struct input_dev *dev,
807 				    struct input_keymap_entry *ke)
808 {
809 	unsigned int index;
810 	int error;
811 
812 	if (!dev->keycodesize)
813 		return -EINVAL;
814 
815 	if (ke->flags & INPUT_KEYMAP_BY_INDEX)
816 		index = ke->index;
817 	else {
818 		error = input_scancode_to_scalar(ke, &index);
819 		if (error)
820 			return error;
821 	}
822 
823 	if (index >= dev->keycodemax)
824 		return -EINVAL;
825 
826 	ke->keycode = input_fetch_keycode(dev, index);
827 	ke->index = index;
828 	ke->len = sizeof(index);
829 	memcpy(ke->scancode, &index, sizeof(index));
830 
831 	return 0;
832 }
833 
input_default_setkeycode(struct input_dev * dev,const struct input_keymap_entry * ke,unsigned int * old_keycode)834 static int input_default_setkeycode(struct input_dev *dev,
835 				    const struct input_keymap_entry *ke,
836 				    unsigned int *old_keycode)
837 {
838 	unsigned int index;
839 	int error;
840 	int i;
841 
842 	if (!dev->keycodesize)
843 		return -EINVAL;
844 
845 	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
846 		index = ke->index;
847 	} else {
848 		error = input_scancode_to_scalar(ke, &index);
849 		if (error)
850 			return error;
851 	}
852 
853 	if (index >= dev->keycodemax)
854 		return -EINVAL;
855 
856 	if (dev->keycodesize < sizeof(ke->keycode) &&
857 			(ke->keycode >> (dev->keycodesize * 8)))
858 		return -EINVAL;
859 
860 	switch (dev->keycodesize) {
861 		case 1: {
862 			u8 *k = (u8 *)dev->keycode;
863 			*old_keycode = k[index];
864 			k[index] = ke->keycode;
865 			break;
866 		}
867 		case 2: {
868 			u16 *k = (u16 *)dev->keycode;
869 			*old_keycode = k[index];
870 			k[index] = ke->keycode;
871 			break;
872 		}
873 		default: {
874 			u32 *k = (u32 *)dev->keycode;
875 			*old_keycode = k[index];
876 			k[index] = ke->keycode;
877 			break;
878 		}
879 	}
880 
881 	if (*old_keycode <= KEY_MAX) {
882 		__clear_bit(*old_keycode, dev->keybit);
883 		for (i = 0; i < dev->keycodemax; i++) {
884 			if (input_fetch_keycode(dev, i) == *old_keycode) {
885 				__set_bit(*old_keycode, dev->keybit);
886 				/* Setting the bit twice is useless, so break */
887 				break;
888 			}
889 		}
890 	}
891 
892 	__set_bit(ke->keycode, dev->keybit);
893 	return 0;
894 }
895 
896 /**
897  * input_get_keycode - retrieve keycode currently mapped to a given scancode
898  * @dev: input device which keymap is being queried
899  * @ke: keymap entry
900  *
901  * This function should be called by anyone interested in retrieving current
902  * keymap. Presently evdev handlers use it.
903  */
input_get_keycode(struct input_dev * dev,struct input_keymap_entry * ke)904 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
905 {
906 	unsigned long flags;
907 	int retval;
908 
909 	spin_lock_irqsave(&dev->event_lock, flags);
910 	retval = dev->getkeycode(dev, ke);
911 	spin_unlock_irqrestore(&dev->event_lock, flags);
912 
913 	return retval;
914 }
915 EXPORT_SYMBOL(input_get_keycode);
916 
917 /**
918  * input_set_keycode - attribute a keycode to a given scancode
919  * @dev: input device which keymap is being updated
920  * @ke: new keymap entry
921  *
922  * This function should be called by anyone needing to update current
923  * keymap. Presently keyboard and evdev handlers use it.
924  */
input_set_keycode(struct input_dev * dev,const struct input_keymap_entry * ke)925 int input_set_keycode(struct input_dev *dev,
926 		      const struct input_keymap_entry *ke)
927 {
928 	unsigned long flags;
929 	unsigned int old_keycode;
930 	int retval;
931 
932 	if (ke->keycode > KEY_MAX)
933 		return -EINVAL;
934 
935 	spin_lock_irqsave(&dev->event_lock, flags);
936 
937 	retval = dev->setkeycode(dev, ke, &old_keycode);
938 	if (retval)
939 		goto out;
940 
941 	/* Make sure KEY_RESERVED did not get enabled. */
942 	__clear_bit(KEY_RESERVED, dev->keybit);
943 
944 	/*
945 	 * Simulate keyup event if keycode is not present
946 	 * in the keymap anymore
947 	 */
948 	if (old_keycode > KEY_MAX) {
949 		dev_warn(dev->dev.parent ?: &dev->dev,
950 			 "%s: got too big old keycode %#x\n",
951 			 __func__, old_keycode);
952 	} else if (test_bit(EV_KEY, dev->evbit) &&
953 		   !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
954 		   __test_and_clear_bit(old_keycode, dev->key)) {
955 		struct input_value vals[] =  {
956 			{ EV_KEY, old_keycode, 0 },
957 			input_value_sync
958 		};
959 
960 		input_pass_values(dev, vals, ARRAY_SIZE(vals));
961 	}
962 
963  out:
964 	spin_unlock_irqrestore(&dev->event_lock, flags);
965 
966 	return retval;
967 }
968 EXPORT_SYMBOL(input_set_keycode);
969 
input_match_device_id(const struct input_dev * dev,const struct input_device_id * id)970 bool input_match_device_id(const struct input_dev *dev,
971 			   const struct input_device_id *id)
972 {
973 	if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
974 		if (id->bustype != dev->id.bustype)
975 			return false;
976 
977 	if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
978 		if (id->vendor != dev->id.vendor)
979 			return false;
980 
981 	if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
982 		if (id->product != dev->id.product)
983 			return false;
984 
985 	if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
986 		if (id->version != dev->id.version)
987 			return false;
988 
989 	if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
990 	    !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
991 	    !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
992 	    !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
993 	    !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
994 	    !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
995 	    !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
996 	    !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
997 	    !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
998 	    !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
999 		return false;
1000 	}
1001 
1002 	return true;
1003 }
1004 EXPORT_SYMBOL(input_match_device_id);
1005 
input_match_device(struct input_handler * handler,struct input_dev * dev)1006 static const struct input_device_id *input_match_device(struct input_handler *handler,
1007 							struct input_dev *dev)
1008 {
1009 	const struct input_device_id *id;
1010 
1011 	for (id = handler->id_table; id->flags || id->driver_info; id++) {
1012 		if (input_match_device_id(dev, id) &&
1013 		    (!handler->match || handler->match(handler, dev))) {
1014 			return id;
1015 		}
1016 	}
1017 
1018 	return NULL;
1019 }
1020 
input_attach_handler(struct input_dev * dev,struct input_handler * handler)1021 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1022 {
1023 	const struct input_device_id *id;
1024 	int error;
1025 
1026 	id = input_match_device(handler, dev);
1027 	if (!id)
1028 		return -ENODEV;
1029 
1030 	error = handler->connect(handler, dev, id);
1031 	if (error && error != -ENODEV)
1032 		pr_err("failed to attach handler %s to device %s, error: %d\n",
1033 		       handler->name, kobject_name(&dev->dev.kobj), error);
1034 
1035 	return error;
1036 }
1037 
1038 #ifdef CONFIG_COMPAT
1039 
input_bits_to_string(char * buf,int buf_size,unsigned long bits,bool skip_empty)1040 static int input_bits_to_string(char *buf, int buf_size,
1041 				unsigned long bits, bool skip_empty)
1042 {
1043 	int len = 0;
1044 
1045 	if (in_compat_syscall()) {
1046 		u32 dword = bits >> 32;
1047 		if (dword || !skip_empty)
1048 			len += snprintf(buf, buf_size, "%x ", dword);
1049 
1050 		dword = bits & 0xffffffffUL;
1051 		if (dword || !skip_empty || len)
1052 			len += snprintf(buf + len, max(buf_size - len, 0),
1053 					"%x", dword);
1054 	} else {
1055 		if (bits || !skip_empty)
1056 			len += snprintf(buf, buf_size, "%lx", bits);
1057 	}
1058 
1059 	return len;
1060 }
1061 
1062 #else /* !CONFIG_COMPAT */
1063 
input_bits_to_string(char * buf,int buf_size,unsigned long bits,bool skip_empty)1064 static int input_bits_to_string(char *buf, int buf_size,
1065 				unsigned long bits, bool skip_empty)
1066 {
1067 	return bits || !skip_empty ?
1068 		snprintf(buf, buf_size, "%lx", bits) : 0;
1069 }
1070 
1071 #endif
1072 
1073 #ifdef CONFIG_PROC_FS
1074 
1075 static struct proc_dir_entry *proc_bus_input_dir;
1076 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1077 static int input_devices_state;
1078 
input_wakeup_procfs_readers(void)1079 static inline void input_wakeup_procfs_readers(void)
1080 {
1081 	input_devices_state++;
1082 	wake_up(&input_devices_poll_wait);
1083 }
1084 
input_proc_devices_poll(struct file * file,poll_table * wait)1085 static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1086 {
1087 	poll_wait(file, &input_devices_poll_wait, wait);
1088 	if (file->f_version != input_devices_state) {
1089 		file->f_version = input_devices_state;
1090 		return EPOLLIN | EPOLLRDNORM;
1091 	}
1092 
1093 	return 0;
1094 }
1095 
1096 union input_seq_state {
1097 	struct {
1098 		unsigned short pos;
1099 		bool mutex_acquired;
1100 	};
1101 	void *p;
1102 };
1103 
input_devices_seq_start(struct seq_file * seq,loff_t * pos)1104 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1105 {
1106 	union input_seq_state *state = (union input_seq_state *)&seq->private;
1107 	int error;
1108 
1109 	/* We need to fit into seq->private pointer */
1110 	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1111 
1112 	error = mutex_lock_interruptible(&input_mutex);
1113 	if (error) {
1114 		state->mutex_acquired = false;
1115 		return ERR_PTR(error);
1116 	}
1117 
1118 	state->mutex_acquired = true;
1119 
1120 	return seq_list_start(&input_dev_list, *pos);
1121 }
1122 
input_devices_seq_next(struct seq_file * seq,void * v,loff_t * pos)1123 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1124 {
1125 	return seq_list_next(v, &input_dev_list, pos);
1126 }
1127 
input_seq_stop(struct seq_file * seq,void * v)1128 static void input_seq_stop(struct seq_file *seq, void *v)
1129 {
1130 	union input_seq_state *state = (union input_seq_state *)&seq->private;
1131 
1132 	if (state->mutex_acquired)
1133 		mutex_unlock(&input_mutex);
1134 }
1135 
input_seq_print_bitmap(struct seq_file * seq,const char * name,unsigned long * bitmap,int max)1136 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1137 				   unsigned long *bitmap, int max)
1138 {
1139 	int i;
1140 	bool skip_empty = true;
1141 	char buf[18];
1142 
1143 	seq_printf(seq, "B: %s=", name);
1144 
1145 	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1146 		if (input_bits_to_string(buf, sizeof(buf),
1147 					 bitmap[i], skip_empty)) {
1148 			skip_empty = false;
1149 			seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1150 		}
1151 	}
1152 
1153 	/*
1154 	 * If no output was produced print a single 0.
1155 	 */
1156 	if (skip_empty)
1157 		seq_putc(seq, '0');
1158 
1159 	seq_putc(seq, '\n');
1160 }
1161 
input_devices_seq_show(struct seq_file * seq,void * v)1162 static int input_devices_seq_show(struct seq_file *seq, void *v)
1163 {
1164 	struct input_dev *dev = container_of(v, struct input_dev, node);
1165 	const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1166 	struct input_handle *handle;
1167 
1168 	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1169 		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1170 
1171 	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1172 	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1173 	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1174 	seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1175 	seq_puts(seq, "H: Handlers=");
1176 
1177 	list_for_each_entry(handle, &dev->h_list, d_node)
1178 		seq_printf(seq, "%s ", handle->name);
1179 	seq_putc(seq, '\n');
1180 
1181 	input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1182 
1183 	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1184 	if (test_bit(EV_KEY, dev->evbit))
1185 		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1186 	if (test_bit(EV_REL, dev->evbit))
1187 		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1188 	if (test_bit(EV_ABS, dev->evbit))
1189 		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1190 	if (test_bit(EV_MSC, dev->evbit))
1191 		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1192 	if (test_bit(EV_LED, dev->evbit))
1193 		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1194 	if (test_bit(EV_SND, dev->evbit))
1195 		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1196 	if (test_bit(EV_FF, dev->evbit))
1197 		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1198 	if (test_bit(EV_SW, dev->evbit))
1199 		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1200 
1201 	seq_putc(seq, '\n');
1202 
1203 	kfree(path);
1204 	return 0;
1205 }
1206 
1207 static const struct seq_operations input_devices_seq_ops = {
1208 	.start	= input_devices_seq_start,
1209 	.next	= input_devices_seq_next,
1210 	.stop	= input_seq_stop,
1211 	.show	= input_devices_seq_show,
1212 };
1213 
input_proc_devices_open(struct inode * inode,struct file * file)1214 static int input_proc_devices_open(struct inode *inode, struct file *file)
1215 {
1216 	return seq_open(file, &input_devices_seq_ops);
1217 }
1218 
1219 static const struct file_operations input_devices_fileops = {
1220 	.owner		= THIS_MODULE,
1221 	.open		= input_proc_devices_open,
1222 	.poll		= input_proc_devices_poll,
1223 	.read		= seq_read,
1224 	.llseek		= seq_lseek,
1225 	.release	= seq_release,
1226 };
1227 
input_handlers_seq_start(struct seq_file * seq,loff_t * pos)1228 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1229 {
1230 	union input_seq_state *state = (union input_seq_state *)&seq->private;
1231 	int error;
1232 
1233 	/* We need to fit into seq->private pointer */
1234 	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1235 
1236 	error = mutex_lock_interruptible(&input_mutex);
1237 	if (error) {
1238 		state->mutex_acquired = false;
1239 		return ERR_PTR(error);
1240 	}
1241 
1242 	state->mutex_acquired = true;
1243 	state->pos = *pos;
1244 
1245 	return seq_list_start(&input_handler_list, *pos);
1246 }
1247 
input_handlers_seq_next(struct seq_file * seq,void * v,loff_t * pos)1248 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1249 {
1250 	union input_seq_state *state = (union input_seq_state *)&seq->private;
1251 
1252 	state->pos = *pos + 1;
1253 	return seq_list_next(v, &input_handler_list, pos);
1254 }
1255 
input_handlers_seq_show(struct seq_file * seq,void * v)1256 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1257 {
1258 	struct input_handler *handler = container_of(v, struct input_handler, node);
1259 	union input_seq_state *state = (union input_seq_state *)&seq->private;
1260 
1261 	seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1262 	if (handler->filter)
1263 		seq_puts(seq, " (filter)");
1264 	if (handler->legacy_minors)
1265 		seq_printf(seq, " Minor=%d", handler->minor);
1266 	seq_putc(seq, '\n');
1267 
1268 	return 0;
1269 }
1270 
1271 static const struct seq_operations input_handlers_seq_ops = {
1272 	.start	= input_handlers_seq_start,
1273 	.next	= input_handlers_seq_next,
1274 	.stop	= input_seq_stop,
1275 	.show	= input_handlers_seq_show,
1276 };
1277 
input_proc_handlers_open(struct inode * inode,struct file * file)1278 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1279 {
1280 	return seq_open(file, &input_handlers_seq_ops);
1281 }
1282 
1283 static const struct file_operations input_handlers_fileops = {
1284 	.owner		= THIS_MODULE,
1285 	.open		= input_proc_handlers_open,
1286 	.read		= seq_read,
1287 	.llseek		= seq_lseek,
1288 	.release	= seq_release,
1289 };
1290 
input_proc_init(void)1291 static int __init input_proc_init(void)
1292 {
1293 	struct proc_dir_entry *entry;
1294 
1295 	proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1296 	if (!proc_bus_input_dir)
1297 		return -ENOMEM;
1298 
1299 	entry = proc_create("devices", 0, proc_bus_input_dir,
1300 			    &input_devices_fileops);
1301 	if (!entry)
1302 		goto fail1;
1303 
1304 	entry = proc_create("handlers", 0, proc_bus_input_dir,
1305 			    &input_handlers_fileops);
1306 	if (!entry)
1307 		goto fail2;
1308 
1309 	return 0;
1310 
1311  fail2:	remove_proc_entry("devices", proc_bus_input_dir);
1312  fail1: remove_proc_entry("bus/input", NULL);
1313 	return -ENOMEM;
1314 }
1315 
input_proc_exit(void)1316 static void input_proc_exit(void)
1317 {
1318 	remove_proc_entry("devices", proc_bus_input_dir);
1319 	remove_proc_entry("handlers", proc_bus_input_dir);
1320 	remove_proc_entry("bus/input", NULL);
1321 }
1322 
1323 #else /* !CONFIG_PROC_FS */
input_wakeup_procfs_readers(void)1324 static inline void input_wakeup_procfs_readers(void) { }
input_proc_init(void)1325 static inline int input_proc_init(void) { return 0; }
input_proc_exit(void)1326 static inline void input_proc_exit(void) { }
1327 #endif
1328 
1329 #define INPUT_DEV_STRING_ATTR_SHOW(name)				\
1330 static ssize_t input_dev_show_##name(struct device *dev,		\
1331 				     struct device_attribute *attr,	\
1332 				     char *buf)				\
1333 {									\
1334 	struct input_dev *input_dev = to_input_dev(dev);		\
1335 									\
1336 	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
1337 			 input_dev->name ? input_dev->name : "");	\
1338 }									\
1339 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1340 
1341 INPUT_DEV_STRING_ATTR_SHOW(name);
1342 INPUT_DEV_STRING_ATTR_SHOW(phys);
1343 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1344 
input_print_modalias_bits(char * buf,int size,char name,unsigned long * bm,unsigned int min_bit,unsigned int max_bit)1345 static int input_print_modalias_bits(char *buf, int size,
1346 				     char name, unsigned long *bm,
1347 				     unsigned int min_bit, unsigned int max_bit)
1348 {
1349 	int len = 0, i;
1350 
1351 	len += snprintf(buf, max(size, 0), "%c", name);
1352 	for (i = min_bit; i < max_bit; i++)
1353 		if (bm[BIT_WORD(i)] & BIT_MASK(i))
1354 			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1355 	return len;
1356 }
1357 
input_print_modalias(char * buf,int size,struct input_dev * id,int add_cr)1358 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1359 				int add_cr)
1360 {
1361 	int len;
1362 
1363 	len = snprintf(buf, max(size, 0),
1364 		       "input:b%04Xv%04Xp%04Xe%04X-",
1365 		       id->id.bustype, id->id.vendor,
1366 		       id->id.product, id->id.version);
1367 
1368 	len += input_print_modalias_bits(buf + len, size - len,
1369 				'e', id->evbit, 0, EV_MAX);
1370 	len += input_print_modalias_bits(buf + len, size - len,
1371 				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1372 	len += input_print_modalias_bits(buf + len, size - len,
1373 				'r', id->relbit, 0, REL_MAX);
1374 	len += input_print_modalias_bits(buf + len, size - len,
1375 				'a', id->absbit, 0, ABS_MAX);
1376 	len += input_print_modalias_bits(buf + len, size - len,
1377 				'm', id->mscbit, 0, MSC_MAX);
1378 	len += input_print_modalias_bits(buf + len, size - len,
1379 				'l', id->ledbit, 0, LED_MAX);
1380 	len += input_print_modalias_bits(buf + len, size - len,
1381 				's', id->sndbit, 0, SND_MAX);
1382 	len += input_print_modalias_bits(buf + len, size - len,
1383 				'f', id->ffbit, 0, FF_MAX);
1384 	len += input_print_modalias_bits(buf + len, size - len,
1385 				'w', id->swbit, 0, SW_MAX);
1386 
1387 	if (add_cr)
1388 		len += snprintf(buf + len, max(size - len, 0), "\n");
1389 
1390 	return len;
1391 }
1392 
input_dev_show_modalias(struct device * dev,struct device_attribute * attr,char * buf)1393 static ssize_t input_dev_show_modalias(struct device *dev,
1394 				       struct device_attribute *attr,
1395 				       char *buf)
1396 {
1397 	struct input_dev *id = to_input_dev(dev);
1398 	ssize_t len;
1399 
1400 	len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1401 
1402 	return min_t(int, len, PAGE_SIZE);
1403 }
1404 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1405 
1406 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1407 			      int max, int add_cr);
1408 
input_dev_show_properties(struct device * dev,struct device_attribute * attr,char * buf)1409 static ssize_t input_dev_show_properties(struct device *dev,
1410 					 struct device_attribute *attr,
1411 					 char *buf)
1412 {
1413 	struct input_dev *input_dev = to_input_dev(dev);
1414 	int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1415 				     INPUT_PROP_MAX, true);
1416 	return min_t(int, len, PAGE_SIZE);
1417 }
1418 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1419 
1420 static struct attribute *input_dev_attrs[] = {
1421 	&dev_attr_name.attr,
1422 	&dev_attr_phys.attr,
1423 	&dev_attr_uniq.attr,
1424 	&dev_attr_modalias.attr,
1425 	&dev_attr_properties.attr,
1426 	NULL
1427 };
1428 
1429 static const struct attribute_group input_dev_attr_group = {
1430 	.attrs	= input_dev_attrs,
1431 };
1432 
1433 #define INPUT_DEV_ID_ATTR(name)						\
1434 static ssize_t input_dev_show_id_##name(struct device *dev,		\
1435 					struct device_attribute *attr,	\
1436 					char *buf)			\
1437 {									\
1438 	struct input_dev *input_dev = to_input_dev(dev);		\
1439 	return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name);	\
1440 }									\
1441 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1442 
1443 INPUT_DEV_ID_ATTR(bustype);
1444 INPUT_DEV_ID_ATTR(vendor);
1445 INPUT_DEV_ID_ATTR(product);
1446 INPUT_DEV_ID_ATTR(version);
1447 
1448 static struct attribute *input_dev_id_attrs[] = {
1449 	&dev_attr_bustype.attr,
1450 	&dev_attr_vendor.attr,
1451 	&dev_attr_product.attr,
1452 	&dev_attr_version.attr,
1453 	NULL
1454 };
1455 
1456 static const struct attribute_group input_dev_id_attr_group = {
1457 	.name	= "id",
1458 	.attrs	= input_dev_id_attrs,
1459 };
1460 
input_print_bitmap(char * buf,int buf_size,unsigned long * bitmap,int max,int add_cr)1461 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1462 			      int max, int add_cr)
1463 {
1464 	int i;
1465 	int len = 0;
1466 	bool skip_empty = true;
1467 
1468 	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1469 		len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1470 					    bitmap[i], skip_empty);
1471 		if (len) {
1472 			skip_empty = false;
1473 			if (i > 0)
1474 				len += snprintf(buf + len, max(buf_size - len, 0), " ");
1475 		}
1476 	}
1477 
1478 	/*
1479 	 * If no output was produced print a single 0.
1480 	 */
1481 	if (len == 0)
1482 		len = snprintf(buf, buf_size, "%d", 0);
1483 
1484 	if (add_cr)
1485 		len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1486 
1487 	return len;
1488 }
1489 
1490 #define INPUT_DEV_CAP_ATTR(ev, bm)					\
1491 static ssize_t input_dev_show_cap_##bm(struct device *dev,		\
1492 				       struct device_attribute *attr,	\
1493 				       char *buf)			\
1494 {									\
1495 	struct input_dev *input_dev = to_input_dev(dev);		\
1496 	int len = input_print_bitmap(buf, PAGE_SIZE,			\
1497 				     input_dev->bm##bit, ev##_MAX,	\
1498 				     true);				\
1499 	return min_t(int, len, PAGE_SIZE);				\
1500 }									\
1501 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1502 
1503 INPUT_DEV_CAP_ATTR(EV, ev);
1504 INPUT_DEV_CAP_ATTR(KEY, key);
1505 INPUT_DEV_CAP_ATTR(REL, rel);
1506 INPUT_DEV_CAP_ATTR(ABS, abs);
1507 INPUT_DEV_CAP_ATTR(MSC, msc);
1508 INPUT_DEV_CAP_ATTR(LED, led);
1509 INPUT_DEV_CAP_ATTR(SND, snd);
1510 INPUT_DEV_CAP_ATTR(FF, ff);
1511 INPUT_DEV_CAP_ATTR(SW, sw);
1512 
1513 static struct attribute *input_dev_caps_attrs[] = {
1514 	&dev_attr_ev.attr,
1515 	&dev_attr_key.attr,
1516 	&dev_attr_rel.attr,
1517 	&dev_attr_abs.attr,
1518 	&dev_attr_msc.attr,
1519 	&dev_attr_led.attr,
1520 	&dev_attr_snd.attr,
1521 	&dev_attr_ff.attr,
1522 	&dev_attr_sw.attr,
1523 	NULL
1524 };
1525 
1526 static const struct attribute_group input_dev_caps_attr_group = {
1527 	.name	= "capabilities",
1528 	.attrs	= input_dev_caps_attrs,
1529 };
1530 
1531 static const struct attribute_group *input_dev_attr_groups[] = {
1532 	&input_dev_attr_group,
1533 	&input_dev_id_attr_group,
1534 	&input_dev_caps_attr_group,
1535 	&input_poller_attribute_group,
1536 	NULL
1537 };
1538 
input_dev_release(struct device * device)1539 static void input_dev_release(struct device *device)
1540 {
1541 	struct input_dev *dev = to_input_dev(device);
1542 
1543 	input_ff_destroy(dev);
1544 	input_mt_destroy_slots(dev);
1545 	kfree(dev->poller);
1546 	kfree(dev->absinfo);
1547 	kfree(dev->vals);
1548 	kfree(dev);
1549 
1550 	module_put(THIS_MODULE);
1551 }
1552 
1553 /*
1554  * Input uevent interface - loading event handlers based on
1555  * device bitfields.
1556  */
input_add_uevent_bm_var(struct kobj_uevent_env * env,const char * name,unsigned long * bitmap,int max)1557 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1558 				   const char *name, unsigned long *bitmap, int max)
1559 {
1560 	int len;
1561 
1562 	if (add_uevent_var(env, "%s", name))
1563 		return -ENOMEM;
1564 
1565 	len = input_print_bitmap(&env->buf[env->buflen - 1],
1566 				 sizeof(env->buf) - env->buflen,
1567 				 bitmap, max, false);
1568 	if (len >= (sizeof(env->buf) - env->buflen))
1569 		return -ENOMEM;
1570 
1571 	env->buflen += len;
1572 	return 0;
1573 }
1574 
input_add_uevent_modalias_var(struct kobj_uevent_env * env,struct input_dev * dev)1575 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1576 					 struct input_dev *dev)
1577 {
1578 	int len;
1579 
1580 	if (add_uevent_var(env, "MODALIAS="))
1581 		return -ENOMEM;
1582 
1583 	len = input_print_modalias(&env->buf[env->buflen - 1],
1584 				   sizeof(env->buf) - env->buflen,
1585 				   dev, 0);
1586 	if (len >= (sizeof(env->buf) - env->buflen))
1587 		return -ENOMEM;
1588 
1589 	env->buflen += len;
1590 	return 0;
1591 }
1592 
1593 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
1594 	do {								\
1595 		int err = add_uevent_var(env, fmt, val);		\
1596 		if (err)						\
1597 			return err;					\
1598 	} while (0)
1599 
1600 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
1601 	do {								\
1602 		int err = input_add_uevent_bm_var(env, name, bm, max);	\
1603 		if (err)						\
1604 			return err;					\
1605 	} while (0)
1606 
1607 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
1608 	do {								\
1609 		int err = input_add_uevent_modalias_var(env, dev);	\
1610 		if (err)						\
1611 			return err;					\
1612 	} while (0)
1613 
input_dev_uevent(struct device * device,struct kobj_uevent_env * env)1614 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1615 {
1616 	struct input_dev *dev = to_input_dev(device);
1617 
1618 	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1619 				dev->id.bustype, dev->id.vendor,
1620 				dev->id.product, dev->id.version);
1621 	if (dev->name)
1622 		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1623 	if (dev->phys)
1624 		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1625 	if (dev->uniq)
1626 		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1627 
1628 	INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1629 
1630 	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1631 	if (test_bit(EV_KEY, dev->evbit))
1632 		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1633 	if (test_bit(EV_REL, dev->evbit))
1634 		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1635 	if (test_bit(EV_ABS, dev->evbit))
1636 		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1637 	if (test_bit(EV_MSC, dev->evbit))
1638 		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1639 	if (test_bit(EV_LED, dev->evbit))
1640 		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1641 	if (test_bit(EV_SND, dev->evbit))
1642 		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1643 	if (test_bit(EV_FF, dev->evbit))
1644 		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1645 	if (test_bit(EV_SW, dev->evbit))
1646 		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1647 
1648 	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1649 
1650 	return 0;
1651 }
1652 
1653 #define INPUT_DO_TOGGLE(dev, type, bits, on)				\
1654 	do {								\
1655 		int i;							\
1656 		bool active;						\
1657 									\
1658 		if (!test_bit(EV_##type, dev->evbit))			\
1659 			break;						\
1660 									\
1661 		for_each_set_bit(i, dev->bits##bit, type##_CNT) {	\
1662 			active = test_bit(i, dev->bits);		\
1663 			if (!active && !on)				\
1664 				continue;				\
1665 									\
1666 			dev->event(dev, EV_##type, i, on ? active : 0);	\
1667 		}							\
1668 	} while (0)
1669 
input_dev_toggle(struct input_dev * dev,bool activate)1670 static void input_dev_toggle(struct input_dev *dev, bool activate)
1671 {
1672 	if (!dev->event)
1673 		return;
1674 
1675 	INPUT_DO_TOGGLE(dev, LED, led, activate);
1676 	INPUT_DO_TOGGLE(dev, SND, snd, activate);
1677 
1678 	if (activate && test_bit(EV_REP, dev->evbit)) {
1679 		dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1680 		dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1681 	}
1682 }
1683 
1684 /**
1685  * input_reset_device() - reset/restore the state of input device
1686  * @dev: input device whose state needs to be reset
1687  *
1688  * This function tries to reset the state of an opened input device and
1689  * bring internal state and state if the hardware in sync with each other.
1690  * We mark all keys as released, restore LED state, repeat rate, etc.
1691  */
input_reset_device(struct input_dev * dev)1692 void input_reset_device(struct input_dev *dev)
1693 {
1694 	unsigned long flags;
1695 
1696 	mutex_lock(&dev->mutex);
1697 	spin_lock_irqsave(&dev->event_lock, flags);
1698 
1699 	input_dev_toggle(dev, true);
1700 	input_dev_release_keys(dev);
1701 
1702 	spin_unlock_irqrestore(&dev->event_lock, flags);
1703 	mutex_unlock(&dev->mutex);
1704 }
1705 EXPORT_SYMBOL(input_reset_device);
1706 
1707 #ifdef CONFIG_PM_SLEEP
input_dev_suspend(struct device * dev)1708 static int input_dev_suspend(struct device *dev)
1709 {
1710 	struct input_dev *input_dev = to_input_dev(dev);
1711 
1712 	spin_lock_irq(&input_dev->event_lock);
1713 
1714 	/*
1715 	 * Keys that are pressed now are unlikely to be
1716 	 * still pressed when we resume.
1717 	 */
1718 	input_dev_release_keys(input_dev);
1719 
1720 	/* Turn off LEDs and sounds, if any are active. */
1721 	input_dev_toggle(input_dev, false);
1722 
1723 	spin_unlock_irq(&input_dev->event_lock);
1724 
1725 	return 0;
1726 }
1727 
input_dev_resume(struct device * dev)1728 static int input_dev_resume(struct device *dev)
1729 {
1730 	struct input_dev *input_dev = to_input_dev(dev);
1731 
1732 	spin_lock_irq(&input_dev->event_lock);
1733 
1734 	/* Restore state of LEDs and sounds, if any were active. */
1735 	input_dev_toggle(input_dev, true);
1736 
1737 	spin_unlock_irq(&input_dev->event_lock);
1738 
1739 	return 0;
1740 }
1741 
input_dev_freeze(struct device * dev)1742 static int input_dev_freeze(struct device *dev)
1743 {
1744 	struct input_dev *input_dev = to_input_dev(dev);
1745 
1746 	spin_lock_irq(&input_dev->event_lock);
1747 
1748 	/*
1749 	 * Keys that are pressed now are unlikely to be
1750 	 * still pressed when we resume.
1751 	 */
1752 	input_dev_release_keys(input_dev);
1753 
1754 	spin_unlock_irq(&input_dev->event_lock);
1755 
1756 	return 0;
1757 }
1758 
input_dev_poweroff(struct device * dev)1759 static int input_dev_poweroff(struct device *dev)
1760 {
1761 	struct input_dev *input_dev = to_input_dev(dev);
1762 
1763 	spin_lock_irq(&input_dev->event_lock);
1764 
1765 	/* Turn off LEDs and sounds, if any are active. */
1766 	input_dev_toggle(input_dev, false);
1767 
1768 	spin_unlock_irq(&input_dev->event_lock);
1769 
1770 	return 0;
1771 }
1772 
1773 static const struct dev_pm_ops input_dev_pm_ops = {
1774 	.suspend	= input_dev_suspend,
1775 	.resume		= input_dev_resume,
1776 	.freeze		= input_dev_freeze,
1777 	.poweroff	= input_dev_poweroff,
1778 	.restore	= input_dev_resume,
1779 };
1780 #endif /* CONFIG_PM */
1781 
1782 static const struct device_type input_dev_type = {
1783 	.groups		= input_dev_attr_groups,
1784 	.release	= input_dev_release,
1785 	.uevent		= input_dev_uevent,
1786 #ifdef CONFIG_PM_SLEEP
1787 	.pm		= &input_dev_pm_ops,
1788 #endif
1789 };
1790 
input_devnode(struct device * dev,umode_t * mode)1791 static char *input_devnode(struct device *dev, umode_t *mode)
1792 {
1793 	return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1794 }
1795 
1796 struct class input_class = {
1797 	.name		= "input",
1798 	.devnode	= input_devnode,
1799 };
1800 EXPORT_SYMBOL_GPL(input_class);
1801 
1802 /**
1803  * input_allocate_device - allocate memory for new input device
1804  *
1805  * Returns prepared struct input_dev or %NULL.
1806  *
1807  * NOTE: Use input_free_device() to free devices that have not been
1808  * registered; input_unregister_device() should be used for already
1809  * registered devices.
1810  */
input_allocate_device(void)1811 struct input_dev *input_allocate_device(void)
1812 {
1813 	static atomic_t input_no = ATOMIC_INIT(-1);
1814 	struct input_dev *dev;
1815 
1816 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1817 	if (dev) {
1818 		dev->dev.type = &input_dev_type;
1819 		dev->dev.class = &input_class;
1820 		device_initialize(&dev->dev);
1821 		mutex_init(&dev->mutex);
1822 		spin_lock_init(&dev->event_lock);
1823 		timer_setup(&dev->timer, NULL, 0);
1824 		INIT_LIST_HEAD(&dev->h_list);
1825 		INIT_LIST_HEAD(&dev->node);
1826 
1827 		dev_set_name(&dev->dev, "input%lu",
1828 			     (unsigned long)atomic_inc_return(&input_no));
1829 
1830 		__module_get(THIS_MODULE);
1831 	}
1832 
1833 	return dev;
1834 }
1835 EXPORT_SYMBOL(input_allocate_device);
1836 
1837 struct input_devres {
1838 	struct input_dev *input;
1839 };
1840 
devm_input_device_match(struct device * dev,void * res,void * data)1841 static int devm_input_device_match(struct device *dev, void *res, void *data)
1842 {
1843 	struct input_devres *devres = res;
1844 
1845 	return devres->input == data;
1846 }
1847 
devm_input_device_release(struct device * dev,void * res)1848 static void devm_input_device_release(struct device *dev, void *res)
1849 {
1850 	struct input_devres *devres = res;
1851 	struct input_dev *input = devres->input;
1852 
1853 	dev_dbg(dev, "%s: dropping reference to %s\n",
1854 		__func__, dev_name(&input->dev));
1855 	input_put_device(input);
1856 }
1857 
1858 /**
1859  * devm_input_allocate_device - allocate managed input device
1860  * @dev: device owning the input device being created
1861  *
1862  * Returns prepared struct input_dev or %NULL.
1863  *
1864  * Managed input devices do not need to be explicitly unregistered or
1865  * freed as it will be done automatically when owner device unbinds from
1866  * its driver (or binding fails). Once managed input device is allocated,
1867  * it is ready to be set up and registered in the same fashion as regular
1868  * input device. There are no special devm_input_device_[un]register()
1869  * variants, regular ones work with both managed and unmanaged devices,
1870  * should you need them. In most cases however, managed input device need
1871  * not be explicitly unregistered or freed.
1872  *
1873  * NOTE: the owner device is set up as parent of input device and users
1874  * should not override it.
1875  */
devm_input_allocate_device(struct device * dev)1876 struct input_dev *devm_input_allocate_device(struct device *dev)
1877 {
1878 	struct input_dev *input;
1879 	struct input_devres *devres;
1880 
1881 	devres = devres_alloc(devm_input_device_release,
1882 			      sizeof(*devres), GFP_KERNEL);
1883 	if (!devres)
1884 		return NULL;
1885 
1886 	input = input_allocate_device();
1887 	if (!input) {
1888 		devres_free(devres);
1889 		return NULL;
1890 	}
1891 
1892 	input->dev.parent = dev;
1893 	input->devres_managed = true;
1894 
1895 	devres->input = input;
1896 	devres_add(dev, devres);
1897 
1898 	return input;
1899 }
1900 EXPORT_SYMBOL(devm_input_allocate_device);
1901 
1902 /**
1903  * input_free_device - free memory occupied by input_dev structure
1904  * @dev: input device to free
1905  *
1906  * This function should only be used if input_register_device()
1907  * was not called yet or if it failed. Once device was registered
1908  * use input_unregister_device() and memory will be freed once last
1909  * reference to the device is dropped.
1910  *
1911  * Device should be allocated by input_allocate_device().
1912  *
1913  * NOTE: If there are references to the input device then memory
1914  * will not be freed until last reference is dropped.
1915  */
input_free_device(struct input_dev * dev)1916 void input_free_device(struct input_dev *dev)
1917 {
1918 	if (dev) {
1919 		if (dev->devres_managed)
1920 			WARN_ON(devres_destroy(dev->dev.parent,
1921 						devm_input_device_release,
1922 						devm_input_device_match,
1923 						dev));
1924 		input_put_device(dev);
1925 	}
1926 }
1927 EXPORT_SYMBOL(input_free_device);
1928 
1929 /**
1930  * input_set_timestamp - set timestamp for input events
1931  * @dev: input device to set timestamp for
1932  * @timestamp: the time at which the event has occurred
1933  *   in CLOCK_MONOTONIC
1934  *
1935  * This function is intended to provide to the input system a more
1936  * accurate time of when an event actually occurred. The driver should
1937  * call this function as soon as a timestamp is acquired ensuring
1938  * clock conversions in input_set_timestamp are done correctly.
1939  *
1940  * The system entering suspend state between timestamp acquisition and
1941  * calling input_set_timestamp can result in inaccurate conversions.
1942  */
input_set_timestamp(struct input_dev * dev,ktime_t timestamp)1943 void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
1944 {
1945 	dev->timestamp[INPUT_CLK_MONO] = timestamp;
1946 	dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
1947 	dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
1948 							   TK_OFFS_BOOT);
1949 }
1950 EXPORT_SYMBOL(input_set_timestamp);
1951 
1952 /**
1953  * input_get_timestamp - get timestamp for input events
1954  * @dev: input device to get timestamp from
1955  *
1956  * A valid timestamp is a timestamp of non-zero value.
1957  */
input_get_timestamp(struct input_dev * dev)1958 ktime_t *input_get_timestamp(struct input_dev *dev)
1959 {
1960 	const ktime_t invalid_timestamp = ktime_set(0, 0);
1961 
1962 	if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
1963 		input_set_timestamp(dev, ktime_get());
1964 
1965 	return dev->timestamp;
1966 }
1967 EXPORT_SYMBOL(input_get_timestamp);
1968 
1969 /**
1970  * input_set_capability - mark device as capable of a certain event
1971  * @dev: device that is capable of emitting or accepting event
1972  * @type: type of the event (EV_KEY, EV_REL, etc...)
1973  * @code: event code
1974  *
1975  * In addition to setting up corresponding bit in appropriate capability
1976  * bitmap the function also adjusts dev->evbit.
1977  */
input_set_capability(struct input_dev * dev,unsigned int type,unsigned int code)1978 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1979 {
1980 	switch (type) {
1981 	case EV_KEY:
1982 		__set_bit(code, dev->keybit);
1983 		break;
1984 
1985 	case EV_REL:
1986 		__set_bit(code, dev->relbit);
1987 		break;
1988 
1989 	case EV_ABS:
1990 		input_alloc_absinfo(dev);
1991 		if (!dev->absinfo)
1992 			return;
1993 
1994 		__set_bit(code, dev->absbit);
1995 		break;
1996 
1997 	case EV_MSC:
1998 		__set_bit(code, dev->mscbit);
1999 		break;
2000 
2001 	case EV_SW:
2002 		__set_bit(code, dev->swbit);
2003 		break;
2004 
2005 	case EV_LED:
2006 		__set_bit(code, dev->ledbit);
2007 		break;
2008 
2009 	case EV_SND:
2010 		__set_bit(code, dev->sndbit);
2011 		break;
2012 
2013 	case EV_FF:
2014 		__set_bit(code, dev->ffbit);
2015 		break;
2016 
2017 	case EV_PWR:
2018 		/* do nothing */
2019 		break;
2020 
2021 	default:
2022 		pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2023 		dump_stack();
2024 		return;
2025 	}
2026 
2027 	__set_bit(type, dev->evbit);
2028 }
2029 EXPORT_SYMBOL(input_set_capability);
2030 
input_estimate_events_per_packet(struct input_dev * dev)2031 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2032 {
2033 	int mt_slots;
2034 	int i;
2035 	unsigned int events;
2036 
2037 	if (dev->mt) {
2038 		mt_slots = dev->mt->num_slots;
2039 	} else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2040 		mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2041 			   dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
2042 		mt_slots = clamp(mt_slots, 2, 32);
2043 	} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2044 		mt_slots = 2;
2045 	} else {
2046 		mt_slots = 0;
2047 	}
2048 
2049 	events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2050 
2051 	if (test_bit(EV_ABS, dev->evbit))
2052 		for_each_set_bit(i, dev->absbit, ABS_CNT)
2053 			events += input_is_mt_axis(i) ? mt_slots : 1;
2054 
2055 	if (test_bit(EV_REL, dev->evbit))
2056 		events += bitmap_weight(dev->relbit, REL_CNT);
2057 
2058 	/* Make room for KEY and MSC events */
2059 	events += 7;
2060 
2061 	return events;
2062 }
2063 
2064 #define INPUT_CLEANSE_BITMASK(dev, type, bits)				\
2065 	do {								\
2066 		if (!test_bit(EV_##type, dev->evbit))			\
2067 			memset(dev->bits##bit, 0,			\
2068 				sizeof(dev->bits##bit));		\
2069 	} while (0)
2070 
input_cleanse_bitmasks(struct input_dev * dev)2071 static void input_cleanse_bitmasks(struct input_dev *dev)
2072 {
2073 	INPUT_CLEANSE_BITMASK(dev, KEY, key);
2074 	INPUT_CLEANSE_BITMASK(dev, REL, rel);
2075 	INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2076 	INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2077 	INPUT_CLEANSE_BITMASK(dev, LED, led);
2078 	INPUT_CLEANSE_BITMASK(dev, SND, snd);
2079 	INPUT_CLEANSE_BITMASK(dev, FF, ff);
2080 	INPUT_CLEANSE_BITMASK(dev, SW, sw);
2081 }
2082 
__input_unregister_device(struct input_dev * dev)2083 static void __input_unregister_device(struct input_dev *dev)
2084 {
2085 	struct input_handle *handle, *next;
2086 
2087 	input_disconnect_device(dev);
2088 
2089 	mutex_lock(&input_mutex);
2090 
2091 	list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2092 		handle->handler->disconnect(handle);
2093 	WARN_ON(!list_empty(&dev->h_list));
2094 
2095 	del_timer_sync(&dev->timer);
2096 	list_del_init(&dev->node);
2097 
2098 	input_wakeup_procfs_readers();
2099 
2100 	mutex_unlock(&input_mutex);
2101 
2102 	device_del(&dev->dev);
2103 }
2104 
devm_input_device_unregister(struct device * dev,void * res)2105 static void devm_input_device_unregister(struct device *dev, void *res)
2106 {
2107 	struct input_devres *devres = res;
2108 	struct input_dev *input = devres->input;
2109 
2110 	dev_dbg(dev, "%s: unregistering device %s\n",
2111 		__func__, dev_name(&input->dev));
2112 	__input_unregister_device(input);
2113 }
2114 
2115 /**
2116  * input_enable_softrepeat - enable software autorepeat
2117  * @dev: input device
2118  * @delay: repeat delay
2119  * @period: repeat period
2120  *
2121  * Enable software autorepeat on the input device.
2122  */
input_enable_softrepeat(struct input_dev * dev,int delay,int period)2123 void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2124 {
2125 	dev->timer.function = input_repeat_key;
2126 	dev->rep[REP_DELAY] = delay;
2127 	dev->rep[REP_PERIOD] = period;
2128 }
2129 EXPORT_SYMBOL(input_enable_softrepeat);
2130 
2131 /**
2132  * input_register_device - register device with input core
2133  * @dev: device to be registered
2134  *
2135  * This function registers device with input core. The device must be
2136  * allocated with input_allocate_device() and all it's capabilities
2137  * set up before registering.
2138  * If function fails the device must be freed with input_free_device().
2139  * Once device has been successfully registered it can be unregistered
2140  * with input_unregister_device(); input_free_device() should not be
2141  * called in this case.
2142  *
2143  * Note that this function is also used to register managed input devices
2144  * (ones allocated with devm_input_allocate_device()). Such managed input
2145  * devices need not be explicitly unregistered or freed, their tear down
2146  * is controlled by the devres infrastructure. It is also worth noting
2147  * that tear down of managed input devices is internally a 2-step process:
2148  * registered managed input device is first unregistered, but stays in
2149  * memory and can still handle input_event() calls (although events will
2150  * not be delivered anywhere). The freeing of managed input device will
2151  * happen later, when devres stack is unwound to the point where device
2152  * allocation was made.
2153  */
input_register_device(struct input_dev * dev)2154 int input_register_device(struct input_dev *dev)
2155 {
2156 	struct input_devres *devres = NULL;
2157 	struct input_handler *handler;
2158 	unsigned int packet_size;
2159 	const char *path;
2160 	int error;
2161 
2162 	if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2163 		dev_err(&dev->dev,
2164 			"Absolute device without dev->absinfo, refusing to register\n");
2165 		return -EINVAL;
2166 	}
2167 
2168 	if (dev->devres_managed) {
2169 		devres = devres_alloc(devm_input_device_unregister,
2170 				      sizeof(*devres), GFP_KERNEL);
2171 		if (!devres)
2172 			return -ENOMEM;
2173 
2174 		devres->input = dev;
2175 	}
2176 
2177 	/* Every input device generates EV_SYN/SYN_REPORT events. */
2178 	__set_bit(EV_SYN, dev->evbit);
2179 
2180 	/* KEY_RESERVED is not supposed to be transmitted to userspace. */
2181 	__clear_bit(KEY_RESERVED, dev->keybit);
2182 
2183 	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2184 	input_cleanse_bitmasks(dev);
2185 
2186 	packet_size = input_estimate_events_per_packet(dev);
2187 	if (dev->hint_events_per_packet < packet_size)
2188 		dev->hint_events_per_packet = packet_size;
2189 
2190 	dev->max_vals = dev->hint_events_per_packet + 2;
2191 	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2192 	if (!dev->vals) {
2193 		error = -ENOMEM;
2194 		goto err_devres_free;
2195 	}
2196 
2197 	/*
2198 	 * If delay and period are pre-set by the driver, then autorepeating
2199 	 * is handled by the driver itself and we don't do it in input.c.
2200 	 */
2201 	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2202 		input_enable_softrepeat(dev, 250, 33);
2203 
2204 	if (!dev->getkeycode)
2205 		dev->getkeycode = input_default_getkeycode;
2206 
2207 	if (!dev->setkeycode)
2208 		dev->setkeycode = input_default_setkeycode;
2209 
2210 	if (dev->poller)
2211 		input_dev_poller_finalize(dev->poller);
2212 
2213 	error = device_add(&dev->dev);
2214 	if (error)
2215 		goto err_free_vals;
2216 
2217 	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2218 	pr_info("%s as %s\n",
2219 		dev->name ? dev->name : "Unspecified device",
2220 		path ? path : "N/A");
2221 	kfree(path);
2222 
2223 	error = mutex_lock_interruptible(&input_mutex);
2224 	if (error)
2225 		goto err_device_del;
2226 
2227 	list_add_tail(&dev->node, &input_dev_list);
2228 
2229 	list_for_each_entry(handler, &input_handler_list, node)
2230 		input_attach_handler(dev, handler);
2231 
2232 	input_wakeup_procfs_readers();
2233 
2234 	mutex_unlock(&input_mutex);
2235 
2236 	if (dev->devres_managed) {
2237 		dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2238 			__func__, dev_name(&dev->dev));
2239 		devres_add(dev->dev.parent, devres);
2240 	}
2241 	return 0;
2242 
2243 err_device_del:
2244 	device_del(&dev->dev);
2245 err_free_vals:
2246 	kfree(dev->vals);
2247 	dev->vals = NULL;
2248 err_devres_free:
2249 	devres_free(devres);
2250 	return error;
2251 }
2252 EXPORT_SYMBOL(input_register_device);
2253 
2254 /**
2255  * input_unregister_device - unregister previously registered device
2256  * @dev: device to be unregistered
2257  *
2258  * This function unregisters an input device. Once device is unregistered
2259  * the caller should not try to access it as it may get freed at any moment.
2260  */
input_unregister_device(struct input_dev * dev)2261 void input_unregister_device(struct input_dev *dev)
2262 {
2263 	if (dev->devres_managed) {
2264 		WARN_ON(devres_destroy(dev->dev.parent,
2265 					devm_input_device_unregister,
2266 					devm_input_device_match,
2267 					dev));
2268 		__input_unregister_device(dev);
2269 		/*
2270 		 * We do not do input_put_device() here because it will be done
2271 		 * when 2nd devres fires up.
2272 		 */
2273 	} else {
2274 		__input_unregister_device(dev);
2275 		input_put_device(dev);
2276 	}
2277 }
2278 EXPORT_SYMBOL(input_unregister_device);
2279 
2280 /**
2281  * input_register_handler - register a new input handler
2282  * @handler: handler to be registered
2283  *
2284  * This function registers a new input handler (interface) for input
2285  * devices in the system and attaches it to all input devices that
2286  * are compatible with the handler.
2287  */
input_register_handler(struct input_handler * handler)2288 int input_register_handler(struct input_handler *handler)
2289 {
2290 	struct input_dev *dev;
2291 	int error;
2292 
2293 	error = mutex_lock_interruptible(&input_mutex);
2294 	if (error)
2295 		return error;
2296 
2297 	INIT_LIST_HEAD(&handler->h_list);
2298 
2299 	list_add_tail(&handler->node, &input_handler_list);
2300 
2301 	list_for_each_entry(dev, &input_dev_list, node)
2302 		input_attach_handler(dev, handler);
2303 
2304 	input_wakeup_procfs_readers();
2305 
2306 	mutex_unlock(&input_mutex);
2307 	return 0;
2308 }
2309 EXPORT_SYMBOL(input_register_handler);
2310 
2311 /**
2312  * input_unregister_handler - unregisters an input handler
2313  * @handler: handler to be unregistered
2314  *
2315  * This function disconnects a handler from its input devices and
2316  * removes it from lists of known handlers.
2317  */
input_unregister_handler(struct input_handler * handler)2318 void input_unregister_handler(struct input_handler *handler)
2319 {
2320 	struct input_handle *handle, *next;
2321 
2322 	mutex_lock(&input_mutex);
2323 
2324 	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2325 		handler->disconnect(handle);
2326 	WARN_ON(!list_empty(&handler->h_list));
2327 
2328 	list_del_init(&handler->node);
2329 
2330 	input_wakeup_procfs_readers();
2331 
2332 	mutex_unlock(&input_mutex);
2333 }
2334 EXPORT_SYMBOL(input_unregister_handler);
2335 
2336 /**
2337  * input_handler_for_each_handle - handle iterator
2338  * @handler: input handler to iterate
2339  * @data: data for the callback
2340  * @fn: function to be called for each handle
2341  *
2342  * Iterate over @bus's list of devices, and call @fn for each, passing
2343  * it @data and stop when @fn returns a non-zero value. The function is
2344  * using RCU to traverse the list and therefore may be using in atomic
2345  * contexts. The @fn callback is invoked from RCU critical section and
2346  * thus must not sleep.
2347  */
input_handler_for_each_handle(struct input_handler * handler,void * data,int (* fn)(struct input_handle *,void *))2348 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2349 				  int (*fn)(struct input_handle *, void *))
2350 {
2351 	struct input_handle *handle;
2352 	int retval = 0;
2353 
2354 	rcu_read_lock();
2355 
2356 	list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2357 		retval = fn(handle, data);
2358 		if (retval)
2359 			break;
2360 	}
2361 
2362 	rcu_read_unlock();
2363 
2364 	return retval;
2365 }
2366 EXPORT_SYMBOL(input_handler_for_each_handle);
2367 
2368 /**
2369  * input_register_handle - register a new input handle
2370  * @handle: handle to register
2371  *
2372  * This function puts a new input handle onto device's
2373  * and handler's lists so that events can flow through
2374  * it once it is opened using input_open_device().
2375  *
2376  * This function is supposed to be called from handler's
2377  * connect() method.
2378  */
input_register_handle(struct input_handle * handle)2379 int input_register_handle(struct input_handle *handle)
2380 {
2381 	struct input_handler *handler = handle->handler;
2382 	struct input_dev *dev = handle->dev;
2383 	int error;
2384 
2385 	/*
2386 	 * We take dev->mutex here to prevent race with
2387 	 * input_release_device().
2388 	 */
2389 	error = mutex_lock_interruptible(&dev->mutex);
2390 	if (error)
2391 		return error;
2392 
2393 	/*
2394 	 * Filters go to the head of the list, normal handlers
2395 	 * to the tail.
2396 	 */
2397 	if (handler->filter)
2398 		list_add_rcu(&handle->d_node, &dev->h_list);
2399 	else
2400 		list_add_tail_rcu(&handle->d_node, &dev->h_list);
2401 
2402 	mutex_unlock(&dev->mutex);
2403 
2404 	/*
2405 	 * Since we are supposed to be called from ->connect()
2406 	 * which is mutually exclusive with ->disconnect()
2407 	 * we can't be racing with input_unregister_handle()
2408 	 * and so separate lock is not needed here.
2409 	 */
2410 	list_add_tail_rcu(&handle->h_node, &handler->h_list);
2411 
2412 	if (handler->start)
2413 		handler->start(handle);
2414 
2415 	return 0;
2416 }
2417 EXPORT_SYMBOL(input_register_handle);
2418 
2419 /**
2420  * input_unregister_handle - unregister an input handle
2421  * @handle: handle to unregister
2422  *
2423  * This function removes input handle from device's
2424  * and handler's lists.
2425  *
2426  * This function is supposed to be called from handler's
2427  * disconnect() method.
2428  */
input_unregister_handle(struct input_handle * handle)2429 void input_unregister_handle(struct input_handle *handle)
2430 {
2431 	struct input_dev *dev = handle->dev;
2432 
2433 	list_del_rcu(&handle->h_node);
2434 
2435 	/*
2436 	 * Take dev->mutex to prevent race with input_release_device().
2437 	 */
2438 	mutex_lock(&dev->mutex);
2439 	list_del_rcu(&handle->d_node);
2440 	mutex_unlock(&dev->mutex);
2441 
2442 	synchronize_rcu();
2443 }
2444 EXPORT_SYMBOL(input_unregister_handle);
2445 
2446 /**
2447  * input_get_new_minor - allocates a new input minor number
2448  * @legacy_base: beginning or the legacy range to be searched
2449  * @legacy_num: size of legacy range
2450  * @allow_dynamic: whether we can also take ID from the dynamic range
2451  *
2452  * This function allocates a new device minor for from input major namespace.
2453  * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2454  * parameters and whether ID can be allocated from dynamic range if there are
2455  * no free IDs in legacy range.
2456  */
input_get_new_minor(int legacy_base,unsigned int legacy_num,bool allow_dynamic)2457 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2458 			bool allow_dynamic)
2459 {
2460 	/*
2461 	 * This function should be called from input handler's ->connect()
2462 	 * methods, which are serialized with input_mutex, so no additional
2463 	 * locking is needed here.
2464 	 */
2465 	if (legacy_base >= 0) {
2466 		int minor = ida_simple_get(&input_ida,
2467 					   legacy_base,
2468 					   legacy_base + legacy_num,
2469 					   GFP_KERNEL);
2470 		if (minor >= 0 || !allow_dynamic)
2471 			return minor;
2472 	}
2473 
2474 	return ida_simple_get(&input_ida,
2475 			      INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2476 			      GFP_KERNEL);
2477 }
2478 EXPORT_SYMBOL(input_get_new_minor);
2479 
2480 /**
2481  * input_free_minor - release previously allocated minor
2482  * @minor: minor to be released
2483  *
2484  * This function releases previously allocated input minor so that it can be
2485  * reused later.
2486  */
input_free_minor(unsigned int minor)2487 void input_free_minor(unsigned int minor)
2488 {
2489 	ida_simple_remove(&input_ida, minor);
2490 }
2491 EXPORT_SYMBOL(input_free_minor);
2492 
input_init(void)2493 static int __init input_init(void)
2494 {
2495 	int err;
2496 
2497 	err = class_register(&input_class);
2498 	if (err) {
2499 		pr_err("unable to register input_dev class\n");
2500 		return err;
2501 	}
2502 
2503 	err = input_proc_init();
2504 	if (err)
2505 		goto fail1;
2506 
2507 	err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2508 				     INPUT_MAX_CHAR_DEVICES, "input");
2509 	if (err) {
2510 		pr_err("unable to register char major %d", INPUT_MAJOR);
2511 		goto fail2;
2512 	}
2513 
2514 	return 0;
2515 
2516  fail2:	input_proc_exit();
2517  fail1:	class_unregister(&input_class);
2518 	return err;
2519 }
2520 
input_exit(void)2521 static void __exit input_exit(void)
2522 {
2523 	input_proc_exit();
2524 	unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2525 				 INPUT_MAX_CHAR_DEVICES);
2526 	class_unregister(&input_class);
2527 }
2528 
2529 subsys_initcall(input_init);
2530 module_exit(input_exit);
2531