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