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
50 static const unsigned int input_max_code[EV_CNT] = {
51 [EV_KEY] = KEY_MAX,
52 [EV_REL] = REL_MAX,
53 [EV_ABS] = ABS_MAX,
54 [EV_MSC] = MSC_MAX,
55 [EV_SW] = SW_MAX,
56 [EV_LED] = LED_MAX,
57 [EV_SND] = SND_MAX,
58 [EV_FF] = FF_MAX,
59 };
60
is_event_supported(unsigned int code,unsigned long * bm,unsigned int max)61 static inline int is_event_supported(unsigned int code,
62 unsigned long *bm, unsigned int max)
63 {
64 return code <= max && test_bit(code, bm);
65 }
66
input_defuzz_abs_event(int value,int old_val,int fuzz)67 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
68 {
69 if (fuzz) {
70 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
71 return old_val;
72
73 if (value > old_val - fuzz && value < old_val + fuzz)
74 return (old_val * 3 + value) / 4;
75
76 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
77 return (old_val + value) / 2;
78 }
79
80 return value;
81 }
82
input_start_autorepeat(struct input_dev * dev,int code)83 static void input_start_autorepeat(struct input_dev *dev, int code)
84 {
85 if (test_bit(EV_REP, dev->evbit) &&
86 dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
87 dev->timer.function) {
88 dev->repeat_key = code;
89 mod_timer(&dev->timer,
90 jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
91 }
92 }
93
input_stop_autorepeat(struct input_dev * dev)94 static void input_stop_autorepeat(struct input_dev *dev)
95 {
96 del_timer(&dev->timer);
97 }
98
99 /*
100 * Pass event first through all filters and then, if event has not been
101 * filtered out, through all open handles. This function is called with
102 * dev->event_lock held and interrupts disabled.
103 */
input_to_handler(struct input_handle * handle,struct input_value * vals,unsigned int count)104 static unsigned int input_to_handler(struct input_handle *handle,
105 struct input_value *vals, unsigned int count)
106 {
107 struct input_handler *handler = handle->handler;
108 struct input_value *end = vals;
109 struct input_value *v;
110
111 if (handler->filter) {
112 for (v = vals; v != vals + count; v++) {
113 if (handler->filter(handle, v->type, v->code, v->value))
114 continue;
115 if (end != v)
116 *end = *v;
117 end++;
118 }
119 count = end - vals;
120 }
121
122 if (!count)
123 return 0;
124
125 if (handler->events)
126 handler->events(handle, vals, count);
127 else if (handler->event)
128 for (v = vals; v != vals + count; v++)
129 handler->event(handle, v->type, v->code, v->value);
130
131 return count;
132 }
133
134 /*
135 * Pass values first through all filters and then, if event has not been
136 * filtered out, through all open handles. This function is called with
137 * dev->event_lock held and interrupts disabled.
138 */
input_pass_values(struct input_dev * dev,struct input_value * vals,unsigned int count)139 static void input_pass_values(struct input_dev *dev,
140 struct input_value *vals, unsigned int count)
141 {
142 struct input_handle *handle;
143 struct input_value *v;
144
145 if (!count)
146 return;
147
148 rcu_read_lock();
149
150 handle = rcu_dereference(dev->grab);
151 if (handle) {
152 count = input_to_handler(handle, vals, count);
153 } else {
154 list_for_each_entry_rcu(handle, &dev->h_list, d_node)
155 if (handle->open) {
156 count = input_to_handler(handle, vals, count);
157 if (!count)
158 break;
159 }
160 }
161
162 rcu_read_unlock();
163
164 /* trigger auto repeat for key events */
165 if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
166 for (v = vals; v != vals + count; v++) {
167 if (v->type == EV_KEY && v->value != 2) {
168 if (v->value)
169 input_start_autorepeat(dev, v->code);
170 else
171 input_stop_autorepeat(dev);
172 }
173 }
174 }
175 }
176
input_pass_event(struct input_dev * dev,unsigned int type,unsigned int code,int value)177 static void input_pass_event(struct input_dev *dev,
178 unsigned int type, unsigned int code, int value)
179 {
180 struct input_value vals[] = { { type, code, value } };
181
182 input_pass_values(dev, vals, ARRAY_SIZE(vals));
183 }
184
185 /*
186 * Generate software autorepeat event. Note that we take
187 * dev->event_lock here to avoid racing with input_event
188 * which may cause keys get "stuck".
189 */
input_repeat_key(struct timer_list * t)190 static void input_repeat_key(struct timer_list *t)
191 {
192 struct input_dev *dev = from_timer(dev, t, timer);
193 unsigned long flags;
194
195 spin_lock_irqsave(&dev->event_lock, flags);
196
197 if (test_bit(dev->repeat_key, dev->key) &&
198 is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
199 struct input_value vals[] = {
200 { EV_KEY, dev->repeat_key, 2 },
201 input_value_sync
202 };
203
204 input_set_timestamp(dev, ktime_get());
205 input_pass_values(dev, vals, ARRAY_SIZE(vals));
206
207 if (dev->rep[REP_PERIOD])
208 mod_timer(&dev->timer, jiffies +
209 msecs_to_jiffies(dev->rep[REP_PERIOD]));
210 }
211
212 spin_unlock_irqrestore(&dev->event_lock, flags);
213 }
214
215 #define INPUT_IGNORE_EVENT 0
216 #define INPUT_PASS_TO_HANDLERS 1
217 #define INPUT_PASS_TO_DEVICE 2
218 #define INPUT_SLOT 4
219 #define INPUT_FLUSH 8
220 #define INPUT_PASS_TO_ALL (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
221
input_handle_abs_event(struct input_dev * dev,unsigned int code,int * pval)222 static int input_handle_abs_event(struct input_dev *dev,
223 unsigned int code, int *pval)
224 {
225 struct input_mt *mt = dev->mt;
226 bool is_mt_event;
227 int *pold;
228
229 if (code == ABS_MT_SLOT) {
230 /*
231 * "Stage" the event; we'll flush it later, when we
232 * get actual touch data.
233 */
234 if (mt && *pval >= 0 && *pval < mt->num_slots)
235 mt->slot = *pval;
236
237 return INPUT_IGNORE_EVENT;
238 }
239
240 is_mt_event = input_is_mt_value(code);
241
242 if (!is_mt_event) {
243 pold = &dev->absinfo[code].value;
244 } else if (mt) {
245 pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
246 } else {
247 /*
248 * Bypass filtering for multi-touch events when
249 * not employing slots.
250 */
251 pold = NULL;
252 }
253
254 if (pold) {
255 *pval = input_defuzz_abs_event(*pval, *pold,
256 dev->absinfo[code].fuzz);
257 if (*pold == *pval)
258 return INPUT_IGNORE_EVENT;
259
260 *pold = *pval;
261 }
262
263 /* Flush pending "slot" event */
264 if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
265 input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
266 return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
267 }
268
269 return INPUT_PASS_TO_HANDLERS;
270 }
271
input_get_disposition(struct input_dev * dev,unsigned int type,unsigned int code,int * pval)272 static int input_get_disposition(struct input_dev *dev,
273 unsigned int type, unsigned int code, int *pval)
274 {
275 int disposition = INPUT_IGNORE_EVENT;
276 int value = *pval;
277
278 switch (type) {
279
280 case EV_SYN:
281 switch (code) {
282 case SYN_CONFIG:
283 disposition = INPUT_PASS_TO_ALL;
284 break;
285
286 case SYN_REPORT:
287 disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
288 break;
289 case SYN_MT_REPORT:
290 disposition = INPUT_PASS_TO_HANDLERS;
291 break;
292 }
293 break;
294
295 case EV_KEY:
296 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
297
298 /* auto-repeat bypasses state updates */
299 if (value == 2) {
300 disposition = INPUT_PASS_TO_HANDLERS;
301 break;
302 }
303
304 if (!!test_bit(code, dev->key) != !!value) {
305
306 __change_bit(code, dev->key);
307 disposition = INPUT_PASS_TO_HANDLERS;
308 }
309 }
310 break;
311
312 case EV_SW:
313 if (is_event_supported(code, dev->swbit, SW_MAX) &&
314 !!test_bit(code, dev->sw) != !!value) {
315
316 __change_bit(code, dev->sw);
317 disposition = INPUT_PASS_TO_HANDLERS;
318 }
319 break;
320
321 case EV_ABS:
322 if (is_event_supported(code, dev->absbit, ABS_MAX))
323 disposition = input_handle_abs_event(dev, code, &value);
324
325 break;
326
327 case EV_REL:
328 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
329 disposition = INPUT_PASS_TO_HANDLERS;
330
331 break;
332
333 case EV_MSC:
334 if (is_event_supported(code, dev->mscbit, MSC_MAX))
335 disposition = INPUT_PASS_TO_ALL;
336
337 break;
338
339 case EV_LED:
340 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
341 !!test_bit(code, dev->led) != !!value) {
342
343 __change_bit(code, dev->led);
344 disposition = INPUT_PASS_TO_ALL;
345 }
346 break;
347
348 case EV_SND:
349 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
350
351 if (!!test_bit(code, dev->snd) != !!value)
352 __change_bit(code, dev->snd);
353 disposition = INPUT_PASS_TO_ALL;
354 }
355 break;
356
357 case EV_REP:
358 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
359 dev->rep[code] = value;
360 disposition = INPUT_PASS_TO_ALL;
361 }
362 break;
363
364 case EV_FF:
365 if (value >= 0)
366 disposition = INPUT_PASS_TO_ALL;
367 break;
368
369 case EV_PWR:
370 disposition = INPUT_PASS_TO_ALL;
371 break;
372 }
373
374 *pval = value;
375 return disposition;
376 }
377
input_handle_event(struct input_dev * dev,unsigned int type,unsigned int code,int value)378 static void input_handle_event(struct input_dev *dev,
379 unsigned int type, unsigned int code, int value)
380 {
381 int disposition;
382
383 /* filter-out events from inhibited devices */
384 if (dev->inhibited)
385 return;
386
387 disposition = input_get_disposition(dev, type, code, &value);
388 if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
389 add_input_randomness(type, code, value);
390
391 if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
392 dev->event(dev, type, code, value);
393
394 if (!dev->vals)
395 return;
396
397 if (disposition & INPUT_PASS_TO_HANDLERS) {
398 struct input_value *v;
399
400 if (disposition & INPUT_SLOT) {
401 v = &dev->vals[dev->num_vals++];
402 v->type = EV_ABS;
403 v->code = ABS_MT_SLOT;
404 v->value = dev->mt->slot;
405 }
406
407 v = &dev->vals[dev->num_vals++];
408 v->type = type;
409 v->code = code;
410 v->value = value;
411 }
412
413 if (disposition & INPUT_FLUSH) {
414 if (dev->num_vals >= 2)
415 input_pass_values(dev, dev->vals, dev->num_vals);
416 dev->num_vals = 0;
417 /*
418 * Reset the timestamp on flush so we won't end up
419 * with a stale one. Note we only need to reset the
420 * monolithic one as we use its presence when deciding
421 * whether to generate a synthetic timestamp.
422 */
423 dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
424 } else if (dev->num_vals >= dev->max_vals - 2) {
425 dev->vals[dev->num_vals++] = input_value_sync;
426 input_pass_values(dev, dev->vals, dev->num_vals);
427 dev->num_vals = 0;
428 }
429
430 }
431
432 /**
433 * input_event() - report new input event
434 * @dev: device that generated the event
435 * @type: type of the event
436 * @code: event code
437 * @value: value of the event
438 *
439 * This function should be used by drivers implementing various input
440 * devices to report input events. See also input_inject_event().
441 *
442 * NOTE: input_event() may be safely used right after input device was
443 * allocated with input_allocate_device(), even before it is registered
444 * with input_register_device(), but the event will not reach any of the
445 * input handlers. Such early invocation of input_event() may be used
446 * to 'seed' initial state of a switch or initial position of absolute
447 * axis, etc.
448 */
input_event(struct input_dev * dev,unsigned int type,unsigned int code,int value)449 void input_event(struct input_dev *dev,
450 unsigned int type, unsigned int code, int value)
451 {
452 unsigned long flags;
453
454 if (is_event_supported(type, dev->evbit, EV_MAX)) {
455
456 spin_lock_irqsave(&dev->event_lock, flags);
457 input_handle_event(dev, type, code, value);
458 spin_unlock_irqrestore(&dev->event_lock, flags);
459 }
460 }
461 EXPORT_SYMBOL(input_event);
462
463 /**
464 * input_inject_event() - send input event from input handler
465 * @handle: input handle to send event through
466 * @type: type of the event
467 * @code: event code
468 * @value: value of the event
469 *
470 * Similar to input_event() but will ignore event if device is
471 * "grabbed" and handle injecting event is not the one that owns
472 * the device.
473 */
input_inject_event(struct input_handle * handle,unsigned int type,unsigned int code,int value)474 void input_inject_event(struct input_handle *handle,
475 unsigned int type, unsigned int code, int value)
476 {
477 struct input_dev *dev = handle->dev;
478 struct input_handle *grab;
479 unsigned long flags;
480
481 if (is_event_supported(type, dev->evbit, EV_MAX)) {
482 spin_lock_irqsave(&dev->event_lock, flags);
483
484 rcu_read_lock();
485 grab = rcu_dereference(dev->grab);
486 if (!grab || grab == handle)
487 input_handle_event(dev, type, code, value);
488 rcu_read_unlock();
489
490 spin_unlock_irqrestore(&dev->event_lock, flags);
491 }
492 }
493 EXPORT_SYMBOL(input_inject_event);
494
495 /**
496 * input_alloc_absinfo - allocates array of input_absinfo structs
497 * @dev: the input device emitting absolute events
498 *
499 * If the absinfo struct the caller asked for is already allocated, this
500 * functions will not do anything.
501 */
input_alloc_absinfo(struct input_dev * dev)502 void input_alloc_absinfo(struct input_dev *dev)
503 {
504 if (dev->absinfo)
505 return;
506
507 dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
508 if (!dev->absinfo) {
509 dev_err(dev->dev.parent ?: &dev->dev,
510 "%s: unable to allocate memory\n", __func__);
511 /*
512 * We will handle this allocation failure in
513 * input_register_device() when we refuse to register input
514 * device with ABS bits but without absinfo.
515 */
516 }
517 }
518 EXPORT_SYMBOL(input_alloc_absinfo);
519
input_set_abs_params(struct input_dev * dev,unsigned int axis,int min,int max,int fuzz,int flat)520 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
521 int min, int max, int fuzz, int flat)
522 {
523 struct input_absinfo *absinfo;
524
525 input_alloc_absinfo(dev);
526 if (!dev->absinfo)
527 return;
528
529 absinfo = &dev->absinfo[axis];
530 absinfo->minimum = min;
531 absinfo->maximum = max;
532 absinfo->fuzz = fuzz;
533 absinfo->flat = flat;
534
535 __set_bit(EV_ABS, dev->evbit);
536 __set_bit(axis, dev->absbit);
537 }
538 EXPORT_SYMBOL(input_set_abs_params);
539
540
541 /**
542 * input_grab_device - grabs device for exclusive use
543 * @handle: input handle that wants to own the device
544 *
545 * When a device is grabbed by an input handle all events generated by
546 * the device are delivered only to this handle. Also events injected
547 * by other input handles are ignored while device is grabbed.
548 */
input_grab_device(struct input_handle * handle)549 int input_grab_device(struct input_handle *handle)
550 {
551 struct input_dev *dev = handle->dev;
552 int retval;
553
554 retval = mutex_lock_interruptible(&dev->mutex);
555 if (retval)
556 return retval;
557
558 if (dev->grab) {
559 retval = -EBUSY;
560 goto out;
561 }
562
563 rcu_assign_pointer(dev->grab, handle);
564
565 out:
566 mutex_unlock(&dev->mutex);
567 return retval;
568 }
569 EXPORT_SYMBOL(input_grab_device);
570
__input_release_device(struct input_handle * handle)571 static void __input_release_device(struct input_handle *handle)
572 {
573 struct input_dev *dev = handle->dev;
574 struct input_handle *grabber;
575
576 grabber = rcu_dereference_protected(dev->grab,
577 lockdep_is_held(&dev->mutex));
578 if (grabber == handle) {
579 rcu_assign_pointer(dev->grab, NULL);
580 /* Make sure input_pass_event() notices that grab is gone */
581 synchronize_rcu();
582
583 list_for_each_entry(handle, &dev->h_list, d_node)
584 if (handle->open && handle->handler->start)
585 handle->handler->start(handle);
586 }
587 }
588
589 /**
590 * input_release_device - release previously grabbed device
591 * @handle: input handle that owns the device
592 *
593 * Releases previously grabbed device so that other input handles can
594 * start receiving input events. Upon release all handlers attached
595 * to the device have their start() method called so they have a change
596 * to synchronize device state with the rest of the system.
597 */
input_release_device(struct input_handle * handle)598 void input_release_device(struct input_handle *handle)
599 {
600 struct input_dev *dev = handle->dev;
601
602 mutex_lock(&dev->mutex);
603 __input_release_device(handle);
604 mutex_unlock(&dev->mutex);
605 }
606 EXPORT_SYMBOL(input_release_device);
607
608 /**
609 * input_open_device - open input device
610 * @handle: handle through which device is being accessed
611 *
612 * This function should be called by input handlers when they
613 * want to start receive events from given input device.
614 */
input_open_device(struct input_handle * handle)615 int input_open_device(struct input_handle *handle)
616 {
617 struct input_dev *dev = handle->dev;
618 int retval;
619
620 retval = mutex_lock_interruptible(&dev->mutex);
621 if (retval)
622 return retval;
623
624 if (dev->going_away) {
625 retval = -ENODEV;
626 goto out;
627 }
628
629 handle->open++;
630
631 if (dev->users++ || dev->inhibited) {
632 /*
633 * Device is already opened and/or inhibited,
634 * so we can exit immediately and report success.
635 */
636 goto out;
637 }
638
639 if (dev->open) {
640 retval = dev->open(dev);
641 if (retval) {
642 dev->users--;
643 handle->open--;
644 /*
645 * Make sure we are not delivering any more events
646 * through this handle
647 */
648 synchronize_rcu();
649 goto out;
650 }
651 }
652
653 if (dev->poller)
654 input_dev_poller_start(dev->poller);
655
656 out:
657 mutex_unlock(&dev->mutex);
658 return retval;
659 }
660 EXPORT_SYMBOL(input_open_device);
661
input_flush_device(struct input_handle * handle,struct file * file)662 int input_flush_device(struct input_handle *handle, struct file *file)
663 {
664 struct input_dev *dev = handle->dev;
665 int retval;
666
667 retval = mutex_lock_interruptible(&dev->mutex);
668 if (retval)
669 return retval;
670
671 if (dev->flush)
672 retval = dev->flush(dev, file);
673
674 mutex_unlock(&dev->mutex);
675 return retval;
676 }
677 EXPORT_SYMBOL(input_flush_device);
678
679 /**
680 * input_close_device - close input device
681 * @handle: handle through which device is being accessed
682 *
683 * This function should be called by input handlers when they
684 * want to stop receive events from given input device.
685 */
input_close_device(struct input_handle * handle)686 void input_close_device(struct input_handle *handle)
687 {
688 struct input_dev *dev = handle->dev;
689
690 mutex_lock(&dev->mutex);
691
692 __input_release_device(handle);
693
694 if (!--dev->users && !dev->inhibited) {
695 if (dev->poller)
696 input_dev_poller_stop(dev->poller);
697 if (dev->close)
698 dev->close(dev);
699 }
700
701 if (!--handle->open) {
702 /*
703 * synchronize_rcu() makes sure that input_pass_event()
704 * completed and that no more input events are delivered
705 * through this handle
706 */
707 synchronize_rcu();
708 }
709
710 mutex_unlock(&dev->mutex);
711 }
712 EXPORT_SYMBOL(input_close_device);
713
714 /*
715 * Simulate keyup events for all keys that are marked as pressed.
716 * The function must be called with dev->event_lock held.
717 */
input_dev_release_keys(struct input_dev * dev)718 static void input_dev_release_keys(struct input_dev *dev)
719 {
720 bool need_sync = false;
721 int code;
722
723 if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
724 for_each_set_bit(code, dev->key, KEY_CNT) {
725 input_pass_event(dev, EV_KEY, code, 0);
726 need_sync = true;
727 }
728
729 if (need_sync)
730 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
731
732 memset(dev->key, 0, sizeof(dev->key));
733 }
734 }
735
736 /*
737 * Prepare device for unregistering
738 */
input_disconnect_device(struct input_dev * dev)739 static void input_disconnect_device(struct input_dev *dev)
740 {
741 struct input_handle *handle;
742
743 /*
744 * Mark device as going away. Note that we take dev->mutex here
745 * not to protect access to dev->going_away but rather to ensure
746 * that there are no threads in the middle of input_open_device()
747 */
748 mutex_lock(&dev->mutex);
749 dev->going_away = true;
750 mutex_unlock(&dev->mutex);
751
752 spin_lock_irq(&dev->event_lock);
753
754 /*
755 * Simulate keyup events for all pressed keys so that handlers
756 * are not left with "stuck" keys. The driver may continue
757 * generate events even after we done here but they will not
758 * reach any handlers.
759 */
760 input_dev_release_keys(dev);
761
762 list_for_each_entry(handle, &dev->h_list, d_node)
763 handle->open = 0;
764
765 spin_unlock_irq(&dev->event_lock);
766 }
767
768 /**
769 * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
770 * @ke: keymap entry containing scancode to be converted.
771 * @scancode: pointer to the location where converted scancode should
772 * be stored.
773 *
774 * This function is used to convert scancode stored in &struct keymap_entry
775 * into scalar form understood by legacy keymap handling methods. These
776 * methods expect scancodes to be represented as 'unsigned int'.
777 */
input_scancode_to_scalar(const struct input_keymap_entry * ke,unsigned int * scancode)778 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
779 unsigned int *scancode)
780 {
781 switch (ke->len) {
782 case 1:
783 *scancode = *((u8 *)ke->scancode);
784 break;
785
786 case 2:
787 *scancode = *((u16 *)ke->scancode);
788 break;
789
790 case 4:
791 *scancode = *((u32 *)ke->scancode);
792 break;
793
794 default:
795 return -EINVAL;
796 }
797
798 return 0;
799 }
800 EXPORT_SYMBOL(input_scancode_to_scalar);
801
802 /*
803 * Those routines handle the default case where no [gs]etkeycode() is
804 * defined. In this case, an array indexed by the scancode is used.
805 */
806
input_fetch_keycode(struct input_dev * dev,unsigned int index)807 static unsigned int input_fetch_keycode(struct input_dev *dev,
808 unsigned int index)
809 {
810 switch (dev->keycodesize) {
811 case 1:
812 return ((u8 *)dev->keycode)[index];
813
814 case 2:
815 return ((u16 *)dev->keycode)[index];
816
817 default:
818 return ((u32 *)dev->keycode)[index];
819 }
820 }
821
input_default_getkeycode(struct input_dev * dev,struct input_keymap_entry * ke)822 static int input_default_getkeycode(struct input_dev *dev,
823 struct input_keymap_entry *ke)
824 {
825 unsigned int index;
826 int error;
827
828 if (!dev->keycodesize)
829 return -EINVAL;
830
831 if (ke->flags & INPUT_KEYMAP_BY_INDEX)
832 index = ke->index;
833 else {
834 error = input_scancode_to_scalar(ke, &index);
835 if (error)
836 return error;
837 }
838
839 if (index >= dev->keycodemax)
840 return -EINVAL;
841
842 ke->keycode = input_fetch_keycode(dev, index);
843 ke->index = index;
844 ke->len = sizeof(index);
845 memcpy(ke->scancode, &index, sizeof(index));
846
847 return 0;
848 }
849
input_default_setkeycode(struct input_dev * dev,const struct input_keymap_entry * ke,unsigned int * old_keycode)850 static int input_default_setkeycode(struct input_dev *dev,
851 const struct input_keymap_entry *ke,
852 unsigned int *old_keycode)
853 {
854 unsigned int index;
855 int error;
856 int i;
857
858 if (!dev->keycodesize)
859 return -EINVAL;
860
861 if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
862 index = ke->index;
863 } else {
864 error = input_scancode_to_scalar(ke, &index);
865 if (error)
866 return error;
867 }
868
869 if (index >= dev->keycodemax)
870 return -EINVAL;
871
872 if (dev->keycodesize < sizeof(ke->keycode) &&
873 (ke->keycode >> (dev->keycodesize * 8)))
874 return -EINVAL;
875
876 switch (dev->keycodesize) {
877 case 1: {
878 u8 *k = (u8 *)dev->keycode;
879 *old_keycode = k[index];
880 k[index] = ke->keycode;
881 break;
882 }
883 case 2: {
884 u16 *k = (u16 *)dev->keycode;
885 *old_keycode = k[index];
886 k[index] = ke->keycode;
887 break;
888 }
889 default: {
890 u32 *k = (u32 *)dev->keycode;
891 *old_keycode = k[index];
892 k[index] = ke->keycode;
893 break;
894 }
895 }
896
897 if (*old_keycode <= KEY_MAX) {
898 __clear_bit(*old_keycode, dev->keybit);
899 for (i = 0; i < dev->keycodemax; i++) {
900 if (input_fetch_keycode(dev, i) == *old_keycode) {
901 __set_bit(*old_keycode, dev->keybit);
902 /* Setting the bit twice is useless, so break */
903 break;
904 }
905 }
906 }
907
908 __set_bit(ke->keycode, dev->keybit);
909 return 0;
910 }
911
912 /**
913 * input_get_keycode - retrieve keycode currently mapped to a given scancode
914 * @dev: input device which keymap is being queried
915 * @ke: keymap entry
916 *
917 * This function should be called by anyone interested in retrieving current
918 * keymap. Presently evdev handlers use it.
919 */
input_get_keycode(struct input_dev * dev,struct input_keymap_entry * ke)920 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
921 {
922 unsigned long flags;
923 int retval;
924
925 spin_lock_irqsave(&dev->event_lock, flags);
926 retval = dev->getkeycode(dev, ke);
927 spin_unlock_irqrestore(&dev->event_lock, flags);
928
929 return retval;
930 }
931 EXPORT_SYMBOL(input_get_keycode);
932
933 /**
934 * input_set_keycode - attribute a keycode to a given scancode
935 * @dev: input device which keymap is being updated
936 * @ke: new keymap entry
937 *
938 * This function should be called by anyone needing to update current
939 * keymap. Presently keyboard and evdev handlers use it.
940 */
input_set_keycode(struct input_dev * dev,const struct input_keymap_entry * ke)941 int input_set_keycode(struct input_dev *dev,
942 const struct input_keymap_entry *ke)
943 {
944 unsigned long flags;
945 unsigned int old_keycode;
946 int retval;
947
948 if (ke->keycode > KEY_MAX)
949 return -EINVAL;
950
951 spin_lock_irqsave(&dev->event_lock, flags);
952
953 retval = dev->setkeycode(dev, ke, &old_keycode);
954 if (retval)
955 goto out;
956
957 /* Make sure KEY_RESERVED did not get enabled. */
958 __clear_bit(KEY_RESERVED, dev->keybit);
959
960 /*
961 * Simulate keyup event if keycode is not present
962 * in the keymap anymore
963 */
964 if (old_keycode > KEY_MAX) {
965 dev_warn(dev->dev.parent ?: &dev->dev,
966 "%s: got too big old keycode %#x\n",
967 __func__, old_keycode);
968 } else if (test_bit(EV_KEY, dev->evbit) &&
969 !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
970 __test_and_clear_bit(old_keycode, dev->key)) {
971 struct input_value vals[] = {
972 { EV_KEY, old_keycode, 0 },
973 input_value_sync
974 };
975
976 input_pass_values(dev, vals, ARRAY_SIZE(vals));
977 }
978
979 out:
980 spin_unlock_irqrestore(&dev->event_lock, flags);
981
982 return retval;
983 }
984 EXPORT_SYMBOL(input_set_keycode);
985
input_match_device_id(const struct input_dev * dev,const struct input_device_id * id)986 bool input_match_device_id(const struct input_dev *dev,
987 const struct input_device_id *id)
988 {
989 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
990 if (id->bustype != dev->id.bustype)
991 return false;
992
993 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
994 if (id->vendor != dev->id.vendor)
995 return false;
996
997 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
998 if (id->product != dev->id.product)
999 return false;
1000
1001 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
1002 if (id->version != dev->id.version)
1003 return false;
1004
1005 if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
1006 !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
1007 !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
1008 !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
1009 !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
1010 !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
1011 !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
1012 !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
1013 !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
1014 !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
1015 return false;
1016 }
1017
1018 return true;
1019 }
1020 EXPORT_SYMBOL(input_match_device_id);
1021
input_match_device(struct input_handler * handler,struct input_dev * dev)1022 static const struct input_device_id *input_match_device(struct input_handler *handler,
1023 struct input_dev *dev)
1024 {
1025 const struct input_device_id *id;
1026
1027 for (id = handler->id_table; id->flags || id->driver_info; id++) {
1028 if (input_match_device_id(dev, id) &&
1029 (!handler->match || handler->match(handler, dev))) {
1030 return id;
1031 }
1032 }
1033
1034 return NULL;
1035 }
1036
input_attach_handler(struct input_dev * dev,struct input_handler * handler)1037 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1038 {
1039 const struct input_device_id *id;
1040 int error;
1041
1042 id = input_match_device(handler, dev);
1043 if (!id)
1044 return -ENODEV;
1045
1046 error = handler->connect(handler, dev, id);
1047 if (error && error != -ENODEV)
1048 pr_err("failed to attach handler %s to device %s, error: %d\n",
1049 handler->name, kobject_name(&dev->dev.kobj), error);
1050
1051 return error;
1052 }
1053
1054 #ifdef CONFIG_COMPAT
1055
input_bits_to_string(char * buf,int buf_size,unsigned long bits,bool skip_empty)1056 static int input_bits_to_string(char *buf, int buf_size,
1057 unsigned long bits, bool skip_empty)
1058 {
1059 int len = 0;
1060
1061 if (in_compat_syscall()) {
1062 u32 dword = bits >> 32;
1063 if (dword || !skip_empty)
1064 len += snprintf(buf, buf_size, "%x ", dword);
1065
1066 dword = bits & 0xffffffffUL;
1067 if (dword || !skip_empty || len)
1068 len += snprintf(buf + len, max(buf_size - len, 0),
1069 "%x", dword);
1070 } else {
1071 if (bits || !skip_empty)
1072 len += snprintf(buf, buf_size, "%lx", bits);
1073 }
1074
1075 return len;
1076 }
1077
1078 #else /* !CONFIG_COMPAT */
1079
input_bits_to_string(char * buf,int buf_size,unsigned long bits,bool skip_empty)1080 static int input_bits_to_string(char *buf, int buf_size,
1081 unsigned long bits, bool skip_empty)
1082 {
1083 return bits || !skip_empty ?
1084 snprintf(buf, buf_size, "%lx", bits) : 0;
1085 }
1086
1087 #endif
1088
1089 #ifdef CONFIG_PROC_FS
1090
1091 static struct proc_dir_entry *proc_bus_input_dir;
1092 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1093 static int input_devices_state;
1094
input_wakeup_procfs_readers(void)1095 static inline void input_wakeup_procfs_readers(void)
1096 {
1097 input_devices_state++;
1098 wake_up(&input_devices_poll_wait);
1099 }
1100
input_proc_devices_poll(struct file * file,poll_table * wait)1101 static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1102 {
1103 poll_wait(file, &input_devices_poll_wait, wait);
1104 if (file->f_version != input_devices_state) {
1105 file->f_version = input_devices_state;
1106 return EPOLLIN | EPOLLRDNORM;
1107 }
1108
1109 return 0;
1110 }
1111
1112 union input_seq_state {
1113 struct {
1114 unsigned short pos;
1115 bool mutex_acquired;
1116 };
1117 void *p;
1118 };
1119
input_devices_seq_start(struct seq_file * seq,loff_t * pos)1120 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1121 {
1122 union input_seq_state *state = (union input_seq_state *)&seq->private;
1123 int error;
1124
1125 /* We need to fit into seq->private pointer */
1126 BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1127
1128 error = mutex_lock_interruptible(&input_mutex);
1129 if (error) {
1130 state->mutex_acquired = false;
1131 return ERR_PTR(error);
1132 }
1133
1134 state->mutex_acquired = true;
1135
1136 return seq_list_start(&input_dev_list, *pos);
1137 }
1138
input_devices_seq_next(struct seq_file * seq,void * v,loff_t * pos)1139 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1140 {
1141 return seq_list_next(v, &input_dev_list, pos);
1142 }
1143
input_seq_stop(struct seq_file * seq,void * v)1144 static void input_seq_stop(struct seq_file *seq, void *v)
1145 {
1146 union input_seq_state *state = (union input_seq_state *)&seq->private;
1147
1148 if (state->mutex_acquired)
1149 mutex_unlock(&input_mutex);
1150 }
1151
input_seq_print_bitmap(struct seq_file * seq,const char * name,unsigned long * bitmap,int max)1152 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1153 unsigned long *bitmap, int max)
1154 {
1155 int i;
1156 bool skip_empty = true;
1157 char buf[18];
1158
1159 seq_printf(seq, "B: %s=", name);
1160
1161 for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1162 if (input_bits_to_string(buf, sizeof(buf),
1163 bitmap[i], skip_empty)) {
1164 skip_empty = false;
1165 seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1166 }
1167 }
1168
1169 /*
1170 * If no output was produced print a single 0.
1171 */
1172 if (skip_empty)
1173 seq_putc(seq, '0');
1174
1175 seq_putc(seq, '\n');
1176 }
1177
input_devices_seq_show(struct seq_file * seq,void * v)1178 static int input_devices_seq_show(struct seq_file *seq, void *v)
1179 {
1180 struct input_dev *dev = container_of(v, struct input_dev, node);
1181 const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1182 struct input_handle *handle;
1183
1184 seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1185 dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1186
1187 seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1188 seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1189 seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1190 seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1191 seq_puts(seq, "H: Handlers=");
1192
1193 list_for_each_entry(handle, &dev->h_list, d_node)
1194 seq_printf(seq, "%s ", handle->name);
1195 seq_putc(seq, '\n');
1196
1197 input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1198
1199 input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1200 if (test_bit(EV_KEY, dev->evbit))
1201 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1202 if (test_bit(EV_REL, dev->evbit))
1203 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1204 if (test_bit(EV_ABS, dev->evbit))
1205 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1206 if (test_bit(EV_MSC, dev->evbit))
1207 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1208 if (test_bit(EV_LED, dev->evbit))
1209 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1210 if (test_bit(EV_SND, dev->evbit))
1211 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1212 if (test_bit(EV_FF, dev->evbit))
1213 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1214 if (test_bit(EV_SW, dev->evbit))
1215 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1216
1217 seq_putc(seq, '\n');
1218
1219 kfree(path);
1220 return 0;
1221 }
1222
1223 static const struct seq_operations input_devices_seq_ops = {
1224 .start = input_devices_seq_start,
1225 .next = input_devices_seq_next,
1226 .stop = input_seq_stop,
1227 .show = input_devices_seq_show,
1228 };
1229
input_proc_devices_open(struct inode * inode,struct file * file)1230 static int input_proc_devices_open(struct inode *inode, struct file *file)
1231 {
1232 return seq_open(file, &input_devices_seq_ops);
1233 }
1234
1235 static const struct proc_ops input_devices_proc_ops = {
1236 .proc_open = input_proc_devices_open,
1237 .proc_poll = input_proc_devices_poll,
1238 .proc_read = seq_read,
1239 .proc_lseek = seq_lseek,
1240 .proc_release = seq_release,
1241 };
1242
input_handlers_seq_start(struct seq_file * seq,loff_t * pos)1243 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1244 {
1245 union input_seq_state *state = (union input_seq_state *)&seq->private;
1246 int error;
1247
1248 /* We need to fit into seq->private pointer */
1249 BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1250
1251 error = mutex_lock_interruptible(&input_mutex);
1252 if (error) {
1253 state->mutex_acquired = false;
1254 return ERR_PTR(error);
1255 }
1256
1257 state->mutex_acquired = true;
1258 state->pos = *pos;
1259
1260 return seq_list_start(&input_handler_list, *pos);
1261 }
1262
input_handlers_seq_next(struct seq_file * seq,void * v,loff_t * pos)1263 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1264 {
1265 union input_seq_state *state = (union input_seq_state *)&seq->private;
1266
1267 state->pos = *pos + 1;
1268 return seq_list_next(v, &input_handler_list, pos);
1269 }
1270
input_handlers_seq_show(struct seq_file * seq,void * v)1271 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1272 {
1273 struct input_handler *handler = container_of(v, struct input_handler, node);
1274 union input_seq_state *state = (union input_seq_state *)&seq->private;
1275
1276 seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1277 if (handler->filter)
1278 seq_puts(seq, " (filter)");
1279 if (handler->legacy_minors)
1280 seq_printf(seq, " Minor=%d", handler->minor);
1281 seq_putc(seq, '\n');
1282
1283 return 0;
1284 }
1285
1286 static const struct seq_operations input_handlers_seq_ops = {
1287 .start = input_handlers_seq_start,
1288 .next = input_handlers_seq_next,
1289 .stop = input_seq_stop,
1290 .show = input_handlers_seq_show,
1291 };
1292
input_proc_handlers_open(struct inode * inode,struct file * file)1293 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1294 {
1295 return seq_open(file, &input_handlers_seq_ops);
1296 }
1297
1298 static const struct proc_ops input_handlers_proc_ops = {
1299 .proc_open = input_proc_handlers_open,
1300 .proc_read = seq_read,
1301 .proc_lseek = seq_lseek,
1302 .proc_release = seq_release,
1303 };
1304
input_proc_init(void)1305 static int __init input_proc_init(void)
1306 {
1307 struct proc_dir_entry *entry;
1308
1309 proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1310 if (!proc_bus_input_dir)
1311 return -ENOMEM;
1312
1313 entry = proc_create("devices", 0, proc_bus_input_dir,
1314 &input_devices_proc_ops);
1315 if (!entry)
1316 goto fail1;
1317
1318 entry = proc_create("handlers", 0, proc_bus_input_dir,
1319 &input_handlers_proc_ops);
1320 if (!entry)
1321 goto fail2;
1322
1323 return 0;
1324
1325 fail2: remove_proc_entry("devices", proc_bus_input_dir);
1326 fail1: remove_proc_entry("bus/input", NULL);
1327 return -ENOMEM;
1328 }
1329
input_proc_exit(void)1330 static void input_proc_exit(void)
1331 {
1332 remove_proc_entry("devices", proc_bus_input_dir);
1333 remove_proc_entry("handlers", proc_bus_input_dir);
1334 remove_proc_entry("bus/input", NULL);
1335 }
1336
1337 #else /* !CONFIG_PROC_FS */
input_wakeup_procfs_readers(void)1338 static inline void input_wakeup_procfs_readers(void) { }
input_proc_init(void)1339 static inline int input_proc_init(void) { return 0; }
input_proc_exit(void)1340 static inline void input_proc_exit(void) { }
1341 #endif
1342
1343 #define INPUT_DEV_STRING_ATTR_SHOW(name) \
1344 static ssize_t input_dev_show_##name(struct device *dev, \
1345 struct device_attribute *attr, \
1346 char *buf) \
1347 { \
1348 struct input_dev *input_dev = to_input_dev(dev); \
1349 \
1350 return scnprintf(buf, PAGE_SIZE, "%s\n", \
1351 input_dev->name ? input_dev->name : ""); \
1352 } \
1353 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1354
1355 INPUT_DEV_STRING_ATTR_SHOW(name);
1356 INPUT_DEV_STRING_ATTR_SHOW(phys);
1357 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1358
input_print_modalias_bits(char * buf,int size,char name,unsigned long * bm,unsigned int min_bit,unsigned int max_bit)1359 static int input_print_modalias_bits(char *buf, int size,
1360 char name, unsigned long *bm,
1361 unsigned int min_bit, unsigned int max_bit)
1362 {
1363 int len = 0, i;
1364
1365 len += snprintf(buf, max(size, 0), "%c", name);
1366 for (i = min_bit; i < max_bit; i++)
1367 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1368 len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1369 return len;
1370 }
1371
input_print_modalias(char * buf,int size,struct input_dev * id,int add_cr)1372 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1373 int add_cr)
1374 {
1375 int len;
1376
1377 len = snprintf(buf, max(size, 0),
1378 "input:b%04Xv%04Xp%04Xe%04X-",
1379 id->id.bustype, id->id.vendor,
1380 id->id.product, id->id.version);
1381
1382 len += input_print_modalias_bits(buf + len, size - len,
1383 'e', id->evbit, 0, EV_MAX);
1384 len += input_print_modalias_bits(buf + len, size - len,
1385 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1386 len += input_print_modalias_bits(buf + len, size - len,
1387 'r', id->relbit, 0, REL_MAX);
1388 len += input_print_modalias_bits(buf + len, size - len,
1389 'a', id->absbit, 0, ABS_MAX);
1390 len += input_print_modalias_bits(buf + len, size - len,
1391 'm', id->mscbit, 0, MSC_MAX);
1392 len += input_print_modalias_bits(buf + len, size - len,
1393 'l', id->ledbit, 0, LED_MAX);
1394 len += input_print_modalias_bits(buf + len, size - len,
1395 's', id->sndbit, 0, SND_MAX);
1396 len += input_print_modalias_bits(buf + len, size - len,
1397 'f', id->ffbit, 0, FF_MAX);
1398 len += input_print_modalias_bits(buf + len, size - len,
1399 'w', id->swbit, 0, SW_MAX);
1400
1401 if (add_cr)
1402 len += snprintf(buf + len, max(size - len, 0), "\n");
1403
1404 return len;
1405 }
1406
input_dev_show_modalias(struct device * dev,struct device_attribute * attr,char * buf)1407 static ssize_t input_dev_show_modalias(struct device *dev,
1408 struct device_attribute *attr,
1409 char *buf)
1410 {
1411 struct input_dev *id = to_input_dev(dev);
1412 ssize_t len;
1413
1414 len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1415
1416 return min_t(int, len, PAGE_SIZE);
1417 }
1418 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1419
1420 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1421 int max, int add_cr);
1422
input_dev_show_properties(struct device * dev,struct device_attribute * attr,char * buf)1423 static ssize_t input_dev_show_properties(struct device *dev,
1424 struct device_attribute *attr,
1425 char *buf)
1426 {
1427 struct input_dev *input_dev = to_input_dev(dev);
1428 int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1429 INPUT_PROP_MAX, true);
1430 return min_t(int, len, PAGE_SIZE);
1431 }
1432 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1433
1434 static int input_inhibit_device(struct input_dev *dev);
1435 static int input_uninhibit_device(struct input_dev *dev);
1436
inhibited_show(struct device * dev,struct device_attribute * attr,char * buf)1437 static ssize_t inhibited_show(struct device *dev,
1438 struct device_attribute *attr,
1439 char *buf)
1440 {
1441 struct input_dev *input_dev = to_input_dev(dev);
1442
1443 return scnprintf(buf, PAGE_SIZE, "%d\n", input_dev->inhibited);
1444 }
1445
inhibited_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)1446 static ssize_t inhibited_store(struct device *dev,
1447 struct device_attribute *attr, const char *buf,
1448 size_t len)
1449 {
1450 struct input_dev *input_dev = to_input_dev(dev);
1451 ssize_t rv;
1452 bool inhibited;
1453
1454 if (strtobool(buf, &inhibited))
1455 return -EINVAL;
1456
1457 if (inhibited)
1458 rv = input_inhibit_device(input_dev);
1459 else
1460 rv = input_uninhibit_device(input_dev);
1461
1462 if (rv != 0)
1463 return rv;
1464
1465 return len;
1466 }
1467
1468 static DEVICE_ATTR_RW(inhibited);
1469
1470 static struct attribute *input_dev_attrs[] = {
1471 &dev_attr_name.attr,
1472 &dev_attr_phys.attr,
1473 &dev_attr_uniq.attr,
1474 &dev_attr_modalias.attr,
1475 &dev_attr_properties.attr,
1476 &dev_attr_inhibited.attr,
1477 NULL
1478 };
1479
1480 static const struct attribute_group input_dev_attr_group = {
1481 .attrs = input_dev_attrs,
1482 };
1483
1484 #define INPUT_DEV_ID_ATTR(name) \
1485 static ssize_t input_dev_show_id_##name(struct device *dev, \
1486 struct device_attribute *attr, \
1487 char *buf) \
1488 { \
1489 struct input_dev *input_dev = to_input_dev(dev); \
1490 return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1491 } \
1492 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1493
1494 INPUT_DEV_ID_ATTR(bustype);
1495 INPUT_DEV_ID_ATTR(vendor);
1496 INPUT_DEV_ID_ATTR(product);
1497 INPUT_DEV_ID_ATTR(version);
1498
1499 static struct attribute *input_dev_id_attrs[] = {
1500 &dev_attr_bustype.attr,
1501 &dev_attr_vendor.attr,
1502 &dev_attr_product.attr,
1503 &dev_attr_version.attr,
1504 NULL
1505 };
1506
1507 static const struct attribute_group input_dev_id_attr_group = {
1508 .name = "id",
1509 .attrs = input_dev_id_attrs,
1510 };
1511
input_print_bitmap(char * buf,int buf_size,unsigned long * bitmap,int max,int add_cr)1512 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1513 int max, int add_cr)
1514 {
1515 int i;
1516 int len = 0;
1517 bool skip_empty = true;
1518
1519 for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1520 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1521 bitmap[i], skip_empty);
1522 if (len) {
1523 skip_empty = false;
1524 if (i > 0)
1525 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1526 }
1527 }
1528
1529 /*
1530 * If no output was produced print a single 0.
1531 */
1532 if (len == 0)
1533 len = snprintf(buf, buf_size, "%d", 0);
1534
1535 if (add_cr)
1536 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1537
1538 return len;
1539 }
1540
1541 #define INPUT_DEV_CAP_ATTR(ev, bm) \
1542 static ssize_t input_dev_show_cap_##bm(struct device *dev, \
1543 struct device_attribute *attr, \
1544 char *buf) \
1545 { \
1546 struct input_dev *input_dev = to_input_dev(dev); \
1547 int len = input_print_bitmap(buf, PAGE_SIZE, \
1548 input_dev->bm##bit, ev##_MAX, \
1549 true); \
1550 return min_t(int, len, PAGE_SIZE); \
1551 } \
1552 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1553
1554 INPUT_DEV_CAP_ATTR(EV, ev);
1555 INPUT_DEV_CAP_ATTR(KEY, key);
1556 INPUT_DEV_CAP_ATTR(REL, rel);
1557 INPUT_DEV_CAP_ATTR(ABS, abs);
1558 INPUT_DEV_CAP_ATTR(MSC, msc);
1559 INPUT_DEV_CAP_ATTR(LED, led);
1560 INPUT_DEV_CAP_ATTR(SND, snd);
1561 INPUT_DEV_CAP_ATTR(FF, ff);
1562 INPUT_DEV_CAP_ATTR(SW, sw);
1563
1564 static struct attribute *input_dev_caps_attrs[] = {
1565 &dev_attr_ev.attr,
1566 &dev_attr_key.attr,
1567 &dev_attr_rel.attr,
1568 &dev_attr_abs.attr,
1569 &dev_attr_msc.attr,
1570 &dev_attr_led.attr,
1571 &dev_attr_snd.attr,
1572 &dev_attr_ff.attr,
1573 &dev_attr_sw.attr,
1574 NULL
1575 };
1576
1577 static const struct attribute_group input_dev_caps_attr_group = {
1578 .name = "capabilities",
1579 .attrs = input_dev_caps_attrs,
1580 };
1581
1582 static const struct attribute_group *input_dev_attr_groups[] = {
1583 &input_dev_attr_group,
1584 &input_dev_id_attr_group,
1585 &input_dev_caps_attr_group,
1586 &input_poller_attribute_group,
1587 NULL
1588 };
1589
input_dev_release(struct device * device)1590 static void input_dev_release(struct device *device)
1591 {
1592 struct input_dev *dev = to_input_dev(device);
1593
1594 input_ff_destroy(dev);
1595 input_mt_destroy_slots(dev);
1596 kfree(dev->poller);
1597 kfree(dev->absinfo);
1598 kfree(dev->vals);
1599 kfree(dev);
1600
1601 module_put(THIS_MODULE);
1602 }
1603
1604 /*
1605 * Input uevent interface - loading event handlers based on
1606 * device bitfields.
1607 */
input_add_uevent_bm_var(struct kobj_uevent_env * env,const char * name,unsigned long * bitmap,int max)1608 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1609 const char *name, unsigned long *bitmap, int max)
1610 {
1611 int len;
1612
1613 if (add_uevent_var(env, "%s", name))
1614 return -ENOMEM;
1615
1616 len = input_print_bitmap(&env->buf[env->buflen - 1],
1617 sizeof(env->buf) - env->buflen,
1618 bitmap, max, false);
1619 if (len >= (sizeof(env->buf) - env->buflen))
1620 return -ENOMEM;
1621
1622 env->buflen += len;
1623 return 0;
1624 }
1625
input_add_uevent_modalias_var(struct kobj_uevent_env * env,struct input_dev * dev)1626 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1627 struct input_dev *dev)
1628 {
1629 int len;
1630
1631 if (add_uevent_var(env, "MODALIAS="))
1632 return -ENOMEM;
1633
1634 len = input_print_modalias(&env->buf[env->buflen - 1],
1635 sizeof(env->buf) - env->buflen,
1636 dev, 0);
1637 if (len >= (sizeof(env->buf) - env->buflen))
1638 return -ENOMEM;
1639
1640 env->buflen += len;
1641 return 0;
1642 }
1643
1644 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \
1645 do { \
1646 int err = add_uevent_var(env, fmt, val); \
1647 if (err) \
1648 return err; \
1649 } while (0)
1650
1651 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \
1652 do { \
1653 int err = input_add_uevent_bm_var(env, name, bm, max); \
1654 if (err) \
1655 return err; \
1656 } while (0)
1657
1658 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \
1659 do { \
1660 int err = input_add_uevent_modalias_var(env, dev); \
1661 if (err) \
1662 return err; \
1663 } while (0)
1664
input_dev_uevent(struct device * device,struct kobj_uevent_env * env)1665 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1666 {
1667 struct input_dev *dev = to_input_dev(device);
1668
1669 INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1670 dev->id.bustype, dev->id.vendor,
1671 dev->id.product, dev->id.version);
1672 if (dev->name)
1673 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1674 if (dev->phys)
1675 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1676 if (dev->uniq)
1677 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1678
1679 INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1680
1681 INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1682 if (test_bit(EV_KEY, dev->evbit))
1683 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1684 if (test_bit(EV_REL, dev->evbit))
1685 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1686 if (test_bit(EV_ABS, dev->evbit))
1687 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1688 if (test_bit(EV_MSC, dev->evbit))
1689 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1690 if (test_bit(EV_LED, dev->evbit))
1691 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1692 if (test_bit(EV_SND, dev->evbit))
1693 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1694 if (test_bit(EV_FF, dev->evbit))
1695 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1696 if (test_bit(EV_SW, dev->evbit))
1697 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1698
1699 INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1700
1701 return 0;
1702 }
1703
1704 #define INPUT_DO_TOGGLE(dev, type, bits, on) \
1705 do { \
1706 int i; \
1707 bool active; \
1708 \
1709 if (!test_bit(EV_##type, dev->evbit)) \
1710 break; \
1711 \
1712 for_each_set_bit(i, dev->bits##bit, type##_CNT) { \
1713 active = test_bit(i, dev->bits); \
1714 if (!active && !on) \
1715 continue; \
1716 \
1717 dev->event(dev, EV_##type, i, on ? active : 0); \
1718 } \
1719 } while (0)
1720
input_dev_toggle(struct input_dev * dev,bool activate)1721 static void input_dev_toggle(struct input_dev *dev, bool activate)
1722 {
1723 if (!dev->event)
1724 return;
1725
1726 INPUT_DO_TOGGLE(dev, LED, led, activate);
1727 INPUT_DO_TOGGLE(dev, SND, snd, activate);
1728
1729 if (activate && test_bit(EV_REP, dev->evbit)) {
1730 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1731 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1732 }
1733 }
1734
1735 /**
1736 * input_reset_device() - reset/restore the state of input device
1737 * @dev: input device whose state needs to be reset
1738 *
1739 * This function tries to reset the state of an opened input device and
1740 * bring internal state and state if the hardware in sync with each other.
1741 * We mark all keys as released, restore LED state, repeat rate, etc.
1742 */
input_reset_device(struct input_dev * dev)1743 void input_reset_device(struct input_dev *dev)
1744 {
1745 unsigned long flags;
1746
1747 mutex_lock(&dev->mutex);
1748 spin_lock_irqsave(&dev->event_lock, flags);
1749
1750 input_dev_toggle(dev, true);
1751 input_dev_release_keys(dev);
1752
1753 spin_unlock_irqrestore(&dev->event_lock, flags);
1754 mutex_unlock(&dev->mutex);
1755 }
1756 EXPORT_SYMBOL(input_reset_device);
1757
input_inhibit_device(struct input_dev * dev)1758 static int input_inhibit_device(struct input_dev *dev)
1759 {
1760 int ret = 0;
1761
1762 mutex_lock(&dev->mutex);
1763
1764 if (dev->inhibited)
1765 goto out;
1766
1767 if (dev->users) {
1768 if (dev->close)
1769 dev->close(dev);
1770 if (dev->poller)
1771 input_dev_poller_stop(dev->poller);
1772 }
1773
1774 spin_lock_irq(&dev->event_lock);
1775 input_dev_release_keys(dev);
1776 input_dev_toggle(dev, false);
1777 spin_unlock_irq(&dev->event_lock);
1778
1779 dev->inhibited = true;
1780
1781 out:
1782 mutex_unlock(&dev->mutex);
1783 return ret;
1784 }
1785
input_uninhibit_device(struct input_dev * dev)1786 static int input_uninhibit_device(struct input_dev *dev)
1787 {
1788 int ret = 0;
1789
1790 mutex_lock(&dev->mutex);
1791
1792 if (!dev->inhibited)
1793 goto out;
1794
1795 if (dev->users) {
1796 if (dev->open) {
1797 ret = dev->open(dev);
1798 if (ret)
1799 goto out;
1800 }
1801 if (dev->poller)
1802 input_dev_poller_start(dev->poller);
1803 }
1804
1805 dev->inhibited = false;
1806 spin_lock_irq(&dev->event_lock);
1807 input_dev_toggle(dev, true);
1808 spin_unlock_irq(&dev->event_lock);
1809
1810 out:
1811 mutex_unlock(&dev->mutex);
1812 return ret;
1813 }
1814
1815 #ifdef CONFIG_PM_SLEEP
input_dev_suspend(struct device * dev)1816 static int input_dev_suspend(struct device *dev)
1817 {
1818 struct input_dev *input_dev = to_input_dev(dev);
1819
1820 spin_lock_irq(&input_dev->event_lock);
1821
1822 /*
1823 * Keys that are pressed now are unlikely to be
1824 * still pressed when we resume.
1825 */
1826 input_dev_release_keys(input_dev);
1827
1828 /* Turn off LEDs and sounds, if any are active. */
1829 input_dev_toggle(input_dev, false);
1830
1831 spin_unlock_irq(&input_dev->event_lock);
1832
1833 return 0;
1834 }
1835
input_dev_resume(struct device * dev)1836 static int input_dev_resume(struct device *dev)
1837 {
1838 struct input_dev *input_dev = to_input_dev(dev);
1839
1840 spin_lock_irq(&input_dev->event_lock);
1841
1842 /* Restore state of LEDs and sounds, if any were active. */
1843 input_dev_toggle(input_dev, true);
1844
1845 spin_unlock_irq(&input_dev->event_lock);
1846
1847 return 0;
1848 }
1849
input_dev_freeze(struct device * dev)1850 static int input_dev_freeze(struct device *dev)
1851 {
1852 struct input_dev *input_dev = to_input_dev(dev);
1853
1854 spin_lock_irq(&input_dev->event_lock);
1855
1856 /*
1857 * Keys that are pressed now are unlikely to be
1858 * still pressed when we resume.
1859 */
1860 input_dev_release_keys(input_dev);
1861
1862 spin_unlock_irq(&input_dev->event_lock);
1863
1864 return 0;
1865 }
1866
input_dev_poweroff(struct device * dev)1867 static int input_dev_poweroff(struct device *dev)
1868 {
1869 struct input_dev *input_dev = to_input_dev(dev);
1870
1871 spin_lock_irq(&input_dev->event_lock);
1872
1873 /* Turn off LEDs and sounds, if any are active. */
1874 input_dev_toggle(input_dev, false);
1875
1876 spin_unlock_irq(&input_dev->event_lock);
1877
1878 return 0;
1879 }
1880
1881 static const struct dev_pm_ops input_dev_pm_ops = {
1882 .suspend = input_dev_suspend,
1883 .resume = input_dev_resume,
1884 .freeze = input_dev_freeze,
1885 .poweroff = input_dev_poweroff,
1886 .restore = input_dev_resume,
1887 };
1888 #endif /* CONFIG_PM */
1889
1890 static const struct device_type input_dev_type = {
1891 .groups = input_dev_attr_groups,
1892 .release = input_dev_release,
1893 .uevent = input_dev_uevent,
1894 #ifdef CONFIG_PM_SLEEP
1895 .pm = &input_dev_pm_ops,
1896 #endif
1897 };
1898
input_devnode(struct device * dev,umode_t * mode)1899 static char *input_devnode(struct device *dev, umode_t *mode)
1900 {
1901 return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1902 }
1903
1904 struct class input_class = {
1905 .name = "input",
1906 .devnode = input_devnode,
1907 };
1908 EXPORT_SYMBOL_GPL(input_class);
1909
1910 /**
1911 * input_allocate_device - allocate memory for new input device
1912 *
1913 * Returns prepared struct input_dev or %NULL.
1914 *
1915 * NOTE: Use input_free_device() to free devices that have not been
1916 * registered; input_unregister_device() should be used for already
1917 * registered devices.
1918 */
input_allocate_device(void)1919 struct input_dev *input_allocate_device(void)
1920 {
1921 static atomic_t input_no = ATOMIC_INIT(-1);
1922 struct input_dev *dev;
1923
1924 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1925 if (dev) {
1926 dev->dev.type = &input_dev_type;
1927 dev->dev.class = &input_class;
1928 device_initialize(&dev->dev);
1929 mutex_init(&dev->mutex);
1930 spin_lock_init(&dev->event_lock);
1931 timer_setup(&dev->timer, NULL, 0);
1932 INIT_LIST_HEAD(&dev->h_list);
1933 INIT_LIST_HEAD(&dev->node);
1934
1935 dev_set_name(&dev->dev, "input%lu",
1936 (unsigned long)atomic_inc_return(&input_no));
1937
1938 __module_get(THIS_MODULE);
1939 }
1940
1941 return dev;
1942 }
1943 EXPORT_SYMBOL(input_allocate_device);
1944
1945 struct input_devres {
1946 struct input_dev *input;
1947 };
1948
devm_input_device_match(struct device * dev,void * res,void * data)1949 static int devm_input_device_match(struct device *dev, void *res, void *data)
1950 {
1951 struct input_devres *devres = res;
1952
1953 return devres->input == data;
1954 }
1955
devm_input_device_release(struct device * dev,void * res)1956 static void devm_input_device_release(struct device *dev, void *res)
1957 {
1958 struct input_devres *devres = res;
1959 struct input_dev *input = devres->input;
1960
1961 dev_dbg(dev, "%s: dropping reference to %s\n",
1962 __func__, dev_name(&input->dev));
1963 input_put_device(input);
1964 }
1965
1966 /**
1967 * devm_input_allocate_device - allocate managed input device
1968 * @dev: device owning the input device being created
1969 *
1970 * Returns prepared struct input_dev or %NULL.
1971 *
1972 * Managed input devices do not need to be explicitly unregistered or
1973 * freed as it will be done automatically when owner device unbinds from
1974 * its driver (or binding fails). Once managed input device is allocated,
1975 * it is ready to be set up and registered in the same fashion as regular
1976 * input device. There are no special devm_input_device_[un]register()
1977 * variants, regular ones work with both managed and unmanaged devices,
1978 * should you need them. In most cases however, managed input device need
1979 * not be explicitly unregistered or freed.
1980 *
1981 * NOTE: the owner device is set up as parent of input device and users
1982 * should not override it.
1983 */
devm_input_allocate_device(struct device * dev)1984 struct input_dev *devm_input_allocate_device(struct device *dev)
1985 {
1986 struct input_dev *input;
1987 struct input_devres *devres;
1988
1989 devres = devres_alloc(devm_input_device_release,
1990 sizeof(*devres), GFP_KERNEL);
1991 if (!devres)
1992 return NULL;
1993
1994 input = input_allocate_device();
1995 if (!input) {
1996 devres_free(devres);
1997 return NULL;
1998 }
1999
2000 input->dev.parent = dev;
2001 input->devres_managed = true;
2002
2003 devres->input = input;
2004 devres_add(dev, devres);
2005
2006 return input;
2007 }
2008 EXPORT_SYMBOL(devm_input_allocate_device);
2009
2010 /**
2011 * input_free_device - free memory occupied by input_dev structure
2012 * @dev: input device to free
2013 *
2014 * This function should only be used if input_register_device()
2015 * was not called yet or if it failed. Once device was registered
2016 * use input_unregister_device() and memory will be freed once last
2017 * reference to the device is dropped.
2018 *
2019 * Device should be allocated by input_allocate_device().
2020 *
2021 * NOTE: If there are references to the input device then memory
2022 * will not be freed until last reference is dropped.
2023 */
input_free_device(struct input_dev * dev)2024 void input_free_device(struct input_dev *dev)
2025 {
2026 if (dev) {
2027 if (dev->devres_managed)
2028 WARN_ON(devres_destroy(dev->dev.parent,
2029 devm_input_device_release,
2030 devm_input_device_match,
2031 dev));
2032 input_put_device(dev);
2033 }
2034 }
2035 EXPORT_SYMBOL(input_free_device);
2036
2037 /**
2038 * input_set_timestamp - set timestamp for input events
2039 * @dev: input device to set timestamp for
2040 * @timestamp: the time at which the event has occurred
2041 * in CLOCK_MONOTONIC
2042 *
2043 * This function is intended to provide to the input system a more
2044 * accurate time of when an event actually occurred. The driver should
2045 * call this function as soon as a timestamp is acquired ensuring
2046 * clock conversions in input_set_timestamp are done correctly.
2047 *
2048 * The system entering suspend state between timestamp acquisition and
2049 * calling input_set_timestamp can result in inaccurate conversions.
2050 */
input_set_timestamp(struct input_dev * dev,ktime_t timestamp)2051 void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
2052 {
2053 dev->timestamp[INPUT_CLK_MONO] = timestamp;
2054 dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
2055 dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
2056 TK_OFFS_BOOT);
2057 }
2058 EXPORT_SYMBOL(input_set_timestamp);
2059
2060 /**
2061 * input_get_timestamp - get timestamp for input events
2062 * @dev: input device to get timestamp from
2063 *
2064 * A valid timestamp is a timestamp of non-zero value.
2065 */
input_get_timestamp(struct input_dev * dev)2066 ktime_t *input_get_timestamp(struct input_dev *dev)
2067 {
2068 const ktime_t invalid_timestamp = ktime_set(0, 0);
2069
2070 if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
2071 input_set_timestamp(dev, ktime_get());
2072
2073 return dev->timestamp;
2074 }
2075 EXPORT_SYMBOL(input_get_timestamp);
2076
2077 /**
2078 * input_set_capability - mark device as capable of a certain event
2079 * @dev: device that is capable of emitting or accepting event
2080 * @type: type of the event (EV_KEY, EV_REL, etc...)
2081 * @code: event code
2082 *
2083 * In addition to setting up corresponding bit in appropriate capability
2084 * bitmap the function also adjusts dev->evbit.
2085 */
input_set_capability(struct input_dev * dev,unsigned int type,unsigned int code)2086 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
2087 {
2088 if (type < EV_CNT && input_max_code[type] &&
2089 code > input_max_code[type]) {
2090 pr_err("%s: invalid code %u for type %u\n", __func__, code,
2091 type);
2092 dump_stack();
2093 return;
2094 }
2095
2096 switch (type) {
2097 case EV_KEY:
2098 __set_bit(code, dev->keybit);
2099 break;
2100
2101 case EV_REL:
2102 __set_bit(code, dev->relbit);
2103 break;
2104
2105 case EV_ABS:
2106 input_alloc_absinfo(dev);
2107 if (!dev->absinfo)
2108 return;
2109
2110 __set_bit(code, dev->absbit);
2111 break;
2112
2113 case EV_MSC:
2114 __set_bit(code, dev->mscbit);
2115 break;
2116
2117 case EV_SW:
2118 __set_bit(code, dev->swbit);
2119 break;
2120
2121 case EV_LED:
2122 __set_bit(code, dev->ledbit);
2123 break;
2124
2125 case EV_SND:
2126 __set_bit(code, dev->sndbit);
2127 break;
2128
2129 case EV_FF:
2130 __set_bit(code, dev->ffbit);
2131 break;
2132
2133 case EV_PWR:
2134 /* do nothing */
2135 break;
2136
2137 default:
2138 pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2139 dump_stack();
2140 return;
2141 }
2142
2143 __set_bit(type, dev->evbit);
2144 }
2145 EXPORT_SYMBOL(input_set_capability);
2146
input_estimate_events_per_packet(struct input_dev * dev)2147 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2148 {
2149 int mt_slots;
2150 int i;
2151 unsigned int events;
2152
2153 if (dev->mt) {
2154 mt_slots = dev->mt->num_slots;
2155 } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2156 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2157 dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
2158 mt_slots = clamp(mt_slots, 2, 32);
2159 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2160 mt_slots = 2;
2161 } else {
2162 mt_slots = 0;
2163 }
2164
2165 events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2166
2167 if (test_bit(EV_ABS, dev->evbit))
2168 for_each_set_bit(i, dev->absbit, ABS_CNT)
2169 events += input_is_mt_axis(i) ? mt_slots : 1;
2170
2171 if (test_bit(EV_REL, dev->evbit))
2172 events += bitmap_weight(dev->relbit, REL_CNT);
2173
2174 /* Make room for KEY and MSC events */
2175 events += 7;
2176
2177 return events;
2178 }
2179
2180 #define INPUT_CLEANSE_BITMASK(dev, type, bits) \
2181 do { \
2182 if (!test_bit(EV_##type, dev->evbit)) \
2183 memset(dev->bits##bit, 0, \
2184 sizeof(dev->bits##bit)); \
2185 } while (0)
2186
input_cleanse_bitmasks(struct input_dev * dev)2187 static void input_cleanse_bitmasks(struct input_dev *dev)
2188 {
2189 INPUT_CLEANSE_BITMASK(dev, KEY, key);
2190 INPUT_CLEANSE_BITMASK(dev, REL, rel);
2191 INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2192 INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2193 INPUT_CLEANSE_BITMASK(dev, LED, led);
2194 INPUT_CLEANSE_BITMASK(dev, SND, snd);
2195 INPUT_CLEANSE_BITMASK(dev, FF, ff);
2196 INPUT_CLEANSE_BITMASK(dev, SW, sw);
2197 }
2198
__input_unregister_device(struct input_dev * dev)2199 static void __input_unregister_device(struct input_dev *dev)
2200 {
2201 struct input_handle *handle, *next;
2202
2203 input_disconnect_device(dev);
2204
2205 mutex_lock(&input_mutex);
2206
2207 list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2208 handle->handler->disconnect(handle);
2209 WARN_ON(!list_empty(&dev->h_list));
2210
2211 del_timer_sync(&dev->timer);
2212 list_del_init(&dev->node);
2213
2214 input_wakeup_procfs_readers();
2215
2216 mutex_unlock(&input_mutex);
2217
2218 device_del(&dev->dev);
2219 }
2220
devm_input_device_unregister(struct device * dev,void * res)2221 static void devm_input_device_unregister(struct device *dev, void *res)
2222 {
2223 struct input_devres *devres = res;
2224 struct input_dev *input = devres->input;
2225
2226 dev_dbg(dev, "%s: unregistering device %s\n",
2227 __func__, dev_name(&input->dev));
2228 __input_unregister_device(input);
2229 }
2230
2231 /**
2232 * input_enable_softrepeat - enable software autorepeat
2233 * @dev: input device
2234 * @delay: repeat delay
2235 * @period: repeat period
2236 *
2237 * Enable software autorepeat on the input device.
2238 */
input_enable_softrepeat(struct input_dev * dev,int delay,int period)2239 void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2240 {
2241 dev->timer.function = input_repeat_key;
2242 dev->rep[REP_DELAY] = delay;
2243 dev->rep[REP_PERIOD] = period;
2244 }
2245 EXPORT_SYMBOL(input_enable_softrepeat);
2246
input_device_enabled(struct input_dev * dev)2247 bool input_device_enabled(struct input_dev *dev)
2248 {
2249 lockdep_assert_held(&dev->mutex);
2250
2251 return !dev->inhibited && dev->users > 0;
2252 }
2253 EXPORT_SYMBOL_GPL(input_device_enabled);
2254
2255 /**
2256 * input_register_device - register device with input core
2257 * @dev: device to be registered
2258 *
2259 * This function registers device with input core. The device must be
2260 * allocated with input_allocate_device() and all it's capabilities
2261 * set up before registering.
2262 * If function fails the device must be freed with input_free_device().
2263 * Once device has been successfully registered it can be unregistered
2264 * with input_unregister_device(); input_free_device() should not be
2265 * called in this case.
2266 *
2267 * Note that this function is also used to register managed input devices
2268 * (ones allocated with devm_input_allocate_device()). Such managed input
2269 * devices need not be explicitly unregistered or freed, their tear down
2270 * is controlled by the devres infrastructure. It is also worth noting
2271 * that tear down of managed input devices is internally a 2-step process:
2272 * registered managed input device is first unregistered, but stays in
2273 * memory and can still handle input_event() calls (although events will
2274 * not be delivered anywhere). The freeing of managed input device will
2275 * happen later, when devres stack is unwound to the point where device
2276 * allocation was made.
2277 */
input_register_device(struct input_dev * dev)2278 int input_register_device(struct input_dev *dev)
2279 {
2280 struct input_devres *devres = NULL;
2281 struct input_handler *handler;
2282 unsigned int packet_size;
2283 const char *path;
2284 int error;
2285
2286 if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2287 dev_err(&dev->dev,
2288 "Absolute device without dev->absinfo, refusing to register\n");
2289 return -EINVAL;
2290 }
2291
2292 if (dev->devres_managed) {
2293 devres = devres_alloc(devm_input_device_unregister,
2294 sizeof(*devres), GFP_KERNEL);
2295 if (!devres)
2296 return -ENOMEM;
2297
2298 devres->input = dev;
2299 }
2300
2301 /* Every input device generates EV_SYN/SYN_REPORT events. */
2302 __set_bit(EV_SYN, dev->evbit);
2303
2304 /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2305 __clear_bit(KEY_RESERVED, dev->keybit);
2306
2307 /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2308 input_cleanse_bitmasks(dev);
2309
2310 packet_size = input_estimate_events_per_packet(dev);
2311 if (dev->hint_events_per_packet < packet_size)
2312 dev->hint_events_per_packet = packet_size;
2313
2314 dev->max_vals = dev->hint_events_per_packet + 2;
2315 dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2316 if (!dev->vals) {
2317 error = -ENOMEM;
2318 goto err_devres_free;
2319 }
2320
2321 /*
2322 * If delay and period are pre-set by the driver, then autorepeating
2323 * is handled by the driver itself and we don't do it in input.c.
2324 */
2325 if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2326 input_enable_softrepeat(dev, 250, 33);
2327
2328 if (!dev->getkeycode)
2329 dev->getkeycode = input_default_getkeycode;
2330
2331 if (!dev->setkeycode)
2332 dev->setkeycode = input_default_setkeycode;
2333
2334 if (dev->poller)
2335 input_dev_poller_finalize(dev->poller);
2336
2337 error = device_add(&dev->dev);
2338 if (error)
2339 goto err_free_vals;
2340
2341 path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2342 pr_info("%s as %s\n",
2343 dev->name ? dev->name : "Unspecified device",
2344 path ? path : "N/A");
2345 kfree(path);
2346
2347 error = mutex_lock_interruptible(&input_mutex);
2348 if (error)
2349 goto err_device_del;
2350
2351 list_add_tail(&dev->node, &input_dev_list);
2352
2353 list_for_each_entry(handler, &input_handler_list, node)
2354 input_attach_handler(dev, handler);
2355
2356 input_wakeup_procfs_readers();
2357
2358 mutex_unlock(&input_mutex);
2359
2360 if (dev->devres_managed) {
2361 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2362 __func__, dev_name(&dev->dev));
2363 devres_add(dev->dev.parent, devres);
2364 }
2365 return 0;
2366
2367 err_device_del:
2368 device_del(&dev->dev);
2369 err_free_vals:
2370 kfree(dev->vals);
2371 dev->vals = NULL;
2372 err_devres_free:
2373 devres_free(devres);
2374 return error;
2375 }
2376 EXPORT_SYMBOL(input_register_device);
2377
2378 /**
2379 * input_unregister_device - unregister previously registered device
2380 * @dev: device to be unregistered
2381 *
2382 * This function unregisters an input device. Once device is unregistered
2383 * the caller should not try to access it as it may get freed at any moment.
2384 */
input_unregister_device(struct input_dev * dev)2385 void input_unregister_device(struct input_dev *dev)
2386 {
2387 if (dev->devres_managed) {
2388 WARN_ON(devres_destroy(dev->dev.parent,
2389 devm_input_device_unregister,
2390 devm_input_device_match,
2391 dev));
2392 __input_unregister_device(dev);
2393 /*
2394 * We do not do input_put_device() here because it will be done
2395 * when 2nd devres fires up.
2396 */
2397 } else {
2398 __input_unregister_device(dev);
2399 input_put_device(dev);
2400 }
2401 }
2402 EXPORT_SYMBOL(input_unregister_device);
2403
2404 /**
2405 * input_register_handler - register a new input handler
2406 * @handler: handler to be registered
2407 *
2408 * This function registers a new input handler (interface) for input
2409 * devices in the system and attaches it to all input devices that
2410 * are compatible with the handler.
2411 */
input_register_handler(struct input_handler * handler)2412 int input_register_handler(struct input_handler *handler)
2413 {
2414 struct input_dev *dev;
2415 int error;
2416
2417 error = mutex_lock_interruptible(&input_mutex);
2418 if (error)
2419 return error;
2420
2421 INIT_LIST_HEAD(&handler->h_list);
2422
2423 list_add_tail(&handler->node, &input_handler_list);
2424
2425 list_for_each_entry(dev, &input_dev_list, node)
2426 input_attach_handler(dev, handler);
2427
2428 input_wakeup_procfs_readers();
2429
2430 mutex_unlock(&input_mutex);
2431 return 0;
2432 }
2433 EXPORT_SYMBOL(input_register_handler);
2434
2435 /**
2436 * input_unregister_handler - unregisters an input handler
2437 * @handler: handler to be unregistered
2438 *
2439 * This function disconnects a handler from its input devices and
2440 * removes it from lists of known handlers.
2441 */
input_unregister_handler(struct input_handler * handler)2442 void input_unregister_handler(struct input_handler *handler)
2443 {
2444 struct input_handle *handle, *next;
2445
2446 mutex_lock(&input_mutex);
2447
2448 list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2449 handler->disconnect(handle);
2450 WARN_ON(!list_empty(&handler->h_list));
2451
2452 list_del_init(&handler->node);
2453
2454 input_wakeup_procfs_readers();
2455
2456 mutex_unlock(&input_mutex);
2457 }
2458 EXPORT_SYMBOL(input_unregister_handler);
2459
2460 /**
2461 * input_handler_for_each_handle - handle iterator
2462 * @handler: input handler to iterate
2463 * @data: data for the callback
2464 * @fn: function to be called for each handle
2465 *
2466 * Iterate over @bus's list of devices, and call @fn for each, passing
2467 * it @data and stop when @fn returns a non-zero value. The function is
2468 * using RCU to traverse the list and therefore may be using in atomic
2469 * contexts. The @fn callback is invoked from RCU critical section and
2470 * thus must not sleep.
2471 */
input_handler_for_each_handle(struct input_handler * handler,void * data,int (* fn)(struct input_handle *,void *))2472 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2473 int (*fn)(struct input_handle *, void *))
2474 {
2475 struct input_handle *handle;
2476 int retval = 0;
2477
2478 rcu_read_lock();
2479
2480 list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2481 retval = fn(handle, data);
2482 if (retval)
2483 break;
2484 }
2485
2486 rcu_read_unlock();
2487
2488 return retval;
2489 }
2490 EXPORT_SYMBOL(input_handler_for_each_handle);
2491
2492 /**
2493 * input_register_handle - register a new input handle
2494 * @handle: handle to register
2495 *
2496 * This function puts a new input handle onto device's
2497 * and handler's lists so that events can flow through
2498 * it once it is opened using input_open_device().
2499 *
2500 * This function is supposed to be called from handler's
2501 * connect() method.
2502 */
input_register_handle(struct input_handle * handle)2503 int input_register_handle(struct input_handle *handle)
2504 {
2505 struct input_handler *handler = handle->handler;
2506 struct input_dev *dev = handle->dev;
2507 int error;
2508
2509 /*
2510 * We take dev->mutex here to prevent race with
2511 * input_release_device().
2512 */
2513 error = mutex_lock_interruptible(&dev->mutex);
2514 if (error)
2515 return error;
2516
2517 /*
2518 * Filters go to the head of the list, normal handlers
2519 * to the tail.
2520 */
2521 if (handler->filter)
2522 list_add_rcu(&handle->d_node, &dev->h_list);
2523 else
2524 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2525
2526 mutex_unlock(&dev->mutex);
2527
2528 /*
2529 * Since we are supposed to be called from ->connect()
2530 * which is mutually exclusive with ->disconnect()
2531 * we can't be racing with input_unregister_handle()
2532 * and so separate lock is not needed here.
2533 */
2534 list_add_tail_rcu(&handle->h_node, &handler->h_list);
2535
2536 if (handler->start)
2537 handler->start(handle);
2538
2539 return 0;
2540 }
2541 EXPORT_SYMBOL(input_register_handle);
2542
2543 /**
2544 * input_unregister_handle - unregister an input handle
2545 * @handle: handle to unregister
2546 *
2547 * This function removes input handle from device's
2548 * and handler's lists.
2549 *
2550 * This function is supposed to be called from handler's
2551 * disconnect() method.
2552 */
input_unregister_handle(struct input_handle * handle)2553 void input_unregister_handle(struct input_handle *handle)
2554 {
2555 struct input_dev *dev = handle->dev;
2556
2557 list_del_rcu(&handle->h_node);
2558
2559 /*
2560 * Take dev->mutex to prevent race with input_release_device().
2561 */
2562 mutex_lock(&dev->mutex);
2563 list_del_rcu(&handle->d_node);
2564 mutex_unlock(&dev->mutex);
2565
2566 synchronize_rcu();
2567 }
2568 EXPORT_SYMBOL(input_unregister_handle);
2569
2570 /**
2571 * input_get_new_minor - allocates a new input minor number
2572 * @legacy_base: beginning or the legacy range to be searched
2573 * @legacy_num: size of legacy range
2574 * @allow_dynamic: whether we can also take ID from the dynamic range
2575 *
2576 * This function allocates a new device minor for from input major namespace.
2577 * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2578 * parameters and whether ID can be allocated from dynamic range if there are
2579 * no free IDs in legacy range.
2580 */
input_get_new_minor(int legacy_base,unsigned int legacy_num,bool allow_dynamic)2581 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2582 bool allow_dynamic)
2583 {
2584 /*
2585 * This function should be called from input handler's ->connect()
2586 * methods, which are serialized with input_mutex, so no additional
2587 * locking is needed here.
2588 */
2589 if (legacy_base >= 0) {
2590 int minor = ida_simple_get(&input_ida,
2591 legacy_base,
2592 legacy_base + legacy_num,
2593 GFP_KERNEL);
2594 if (minor >= 0 || !allow_dynamic)
2595 return minor;
2596 }
2597
2598 return ida_simple_get(&input_ida,
2599 INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2600 GFP_KERNEL);
2601 }
2602 EXPORT_SYMBOL(input_get_new_minor);
2603
2604 /**
2605 * input_free_minor - release previously allocated minor
2606 * @minor: minor to be released
2607 *
2608 * This function releases previously allocated input minor so that it can be
2609 * reused later.
2610 */
input_free_minor(unsigned int minor)2611 void input_free_minor(unsigned int minor)
2612 {
2613 ida_simple_remove(&input_ida, minor);
2614 }
2615 EXPORT_SYMBOL(input_free_minor);
2616
input_init(void)2617 static int __init input_init(void)
2618 {
2619 int err;
2620
2621 err = class_register(&input_class);
2622 if (err) {
2623 pr_err("unable to register input_dev class\n");
2624 return err;
2625 }
2626
2627 err = input_proc_init();
2628 if (err)
2629 goto fail1;
2630
2631 err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2632 INPUT_MAX_CHAR_DEVICES, "input");
2633 if (err) {
2634 pr_err("unable to register char major %d", INPUT_MAJOR);
2635 goto fail2;
2636 }
2637
2638 return 0;
2639
2640 fail2: input_proc_exit();
2641 fail1: class_unregister(&input_class);
2642 return err;
2643 }
2644
input_exit(void)2645 static void __exit input_exit(void)
2646 {
2647 input_proc_exit();
2648 unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2649 INPUT_MAX_CHAR_DEVICES);
2650 class_unregister(&input_class);
2651 }
2652
2653 subsys_initcall(input_init);
2654 module_exit(input_exit);
2655