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