Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * The input core
4 *
5 * Copyright (c) 1999-2002 Vojtech Pavlik
6 */
7
8
9#define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
10
11#include <linux/export.h>
12#include <linux/init.h>
13#include <linux/types.h>
14#include <linux/idr.h>
15#include <linux/input/mt.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/random.h>
19#include <linux/major.h>
20#include <linux/proc_fs.h>
21#include <linux/sched.h>
22#include <linux/seq_file.h>
23#include <linux/pm.h>
24#include <linux/poll.h>
25#include <linux/device.h>
26#include <linux/kstrtox.h>
27#include <linux/mutex.h>
28#include <linux/rcupdate.h>
29#include "input-compat.h"
30#include "input-core-private.h"
31#include "input-poller.h"
32
33MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
34MODULE_DESCRIPTION("Input core");
35MODULE_LICENSE("GPL");
36
37#define INPUT_MAX_CHAR_DEVICES 1024
38#define INPUT_FIRST_DYNAMIC_DEV 256
39static DEFINE_IDA(input_ida);
40
41static LIST_HEAD(input_dev_list);
42static LIST_HEAD(input_handler_list);
43
44/*
45 * input_mutex protects access to both input_dev_list and input_handler_list.
46 * This also causes input_[un]register_device and input_[un]register_handler
47 * be mutually exclusive which simplifies locking in drivers implementing
48 * input handlers.
49 */
50static DEFINE_MUTEX(input_mutex);
51
52static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
53
54static const unsigned int input_max_code[EV_CNT] = {
55 [EV_KEY] = KEY_MAX,
56 [EV_REL] = REL_MAX,
57 [EV_ABS] = ABS_MAX,
58 [EV_MSC] = MSC_MAX,
59 [EV_SW] = SW_MAX,
60 [EV_LED] = LED_MAX,
61 [EV_SND] = SND_MAX,
62 [EV_FF] = FF_MAX,
63};
64
65static inline int is_event_supported(unsigned int code,
66 unsigned long *bm, unsigned int max)
67{
68 return code <= max && test_bit(code, bm);
69}
70
71static int input_defuzz_abs_event(int value, int old_val, int fuzz)
72{
73 if (fuzz) {
74 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
75 return old_val;
76
77 if (value > old_val - fuzz && value < old_val + fuzz)
78 return (old_val * 3 + value) / 4;
79
80 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
81 return (old_val + value) / 2;
82 }
83
84 return value;
85}
86
87static void input_start_autorepeat(struct input_dev *dev, int code)
88{
89 if (test_bit(EV_REP, dev->evbit) &&
90 dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
91 dev->timer.function) {
92 dev->repeat_key = code;
93 mod_timer(&dev->timer,
94 jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
95 }
96}
97
98static void input_stop_autorepeat(struct input_dev *dev)
99{
100 timer_delete(&dev->timer);
101}
102
103/*
104 * Pass values first through all filters and then, if event has not been
105 * filtered out, through all open handles. This order is achieved by placing
106 * filters at the head of the list of handles attached to the device, and
107 * placing regular handles at the tail of the list.
108 *
109 * This function is called with dev->event_lock held and interrupts disabled.
110 */
111static void input_pass_values(struct input_dev *dev,
112 struct input_value *vals, unsigned int count)
113{
114 struct input_handle *handle;
115 struct input_value *v;
116
117 lockdep_assert_held(&dev->event_lock);
118
119 scoped_guard(rcu) {
120 handle = rcu_dereference(dev->grab);
121 if (handle) {
122 count = handle->handle_events(handle, vals, count);
123 break;
124 }
125
126 list_for_each_entry_rcu(handle, &dev->h_list, d_node) {
127 if (handle->open) {
128 count = handle->handle_events(handle, vals,
129 count);
130 if (!count)
131 break;
132 }
133 }
134 }
135
136 /* trigger auto repeat for key events */
137 if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
138 for (v = vals; v != vals + count; v++) {
139 if (v->type == EV_KEY && v->value != 2) {
140 if (v->value)
141 input_start_autorepeat(dev, v->code);
142 else
143 input_stop_autorepeat(dev);
144 }
145 }
146 }
147}
148
149#define INPUT_IGNORE_EVENT 0
150#define INPUT_PASS_TO_HANDLERS 1
151#define INPUT_PASS_TO_DEVICE 2
152#define INPUT_SLOT 4
153#define INPUT_FLUSH 8
154#define INPUT_PASS_TO_ALL (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
155
156static int input_handle_abs_event(struct input_dev *dev,
157 unsigned int code, int *pval)
158{
159 struct input_mt *mt = dev->mt;
160 bool is_new_slot = false;
161 bool is_mt_event;
162 int *pold;
163
164 if (code == ABS_MT_SLOT) {
165 /*
166 * "Stage" the event; we'll flush it later, when we
167 * get actual touch data.
168 */
169 if (mt && *pval >= 0 && *pval < mt->num_slots)
170 mt->slot = *pval;
171
172 return INPUT_IGNORE_EVENT;
173 }
174
175 is_mt_event = input_is_mt_value(code);
176
177 if (!is_mt_event) {
178 pold = &dev->absinfo[code].value;
179 } else if (mt) {
180 pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
181 is_new_slot = mt->slot != dev->absinfo[ABS_MT_SLOT].value;
182 } else {
183 /*
184 * Bypass filtering for multi-touch events when
185 * not employing slots.
186 */
187 pold = NULL;
188 }
189
190 if (pold) {
191 *pval = input_defuzz_abs_event(*pval, *pold,
192 dev->absinfo[code].fuzz);
193 if (*pold == *pval)
194 return INPUT_IGNORE_EVENT;
195
196 *pold = *pval;
197 }
198
199 /* Flush pending "slot" event */
200 if (is_new_slot) {
201 dev->absinfo[ABS_MT_SLOT].value = mt->slot;
202 return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
203 }
204
205 return INPUT_PASS_TO_HANDLERS;
206}
207
208static int input_get_disposition(struct input_dev *dev,
209 unsigned int type, unsigned int code, int *pval)
210{
211 int disposition = INPUT_IGNORE_EVENT;
212 int value = *pval;
213
214 /* filter-out events from inhibited devices */
215 if (dev->inhibited)
216 return INPUT_IGNORE_EVENT;
217
218 switch (type) {
219
220 case EV_SYN:
221 switch (code) {
222 case SYN_CONFIG:
223 disposition = INPUT_PASS_TO_ALL;
224 break;
225
226 case SYN_REPORT:
227 disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
228 break;
229 case SYN_MT_REPORT:
230 disposition = INPUT_PASS_TO_HANDLERS;
231 break;
232 }
233 break;
234
235 case EV_KEY:
236 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
237
238 /* auto-repeat bypasses state updates */
239 if (value == 2) {
240 disposition = INPUT_PASS_TO_HANDLERS;
241 break;
242 }
243
244 if (!!test_bit(code, dev->key) != !!value) {
245
246 __change_bit(code, dev->key);
247 disposition = INPUT_PASS_TO_HANDLERS;
248 }
249 }
250 break;
251
252 case EV_SW:
253 if (is_event_supported(code, dev->swbit, SW_MAX) &&
254 !!test_bit(code, dev->sw) != !!value) {
255
256 __change_bit(code, dev->sw);
257 disposition = INPUT_PASS_TO_HANDLERS;
258 }
259 break;
260
261 case EV_ABS:
262 if (is_event_supported(code, dev->absbit, ABS_MAX))
263 disposition = input_handle_abs_event(dev, code, &value);
264
265 break;
266
267 case EV_REL:
268 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
269 disposition = INPUT_PASS_TO_HANDLERS;
270
271 break;
272
273 case EV_MSC:
274 if (is_event_supported(code, dev->mscbit, MSC_MAX))
275 disposition = INPUT_PASS_TO_ALL;
276
277 break;
278
279 case EV_LED:
280 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
281 !!test_bit(code, dev->led) != !!value) {
282
283 __change_bit(code, dev->led);
284 disposition = INPUT_PASS_TO_ALL;
285 }
286 break;
287
288 case EV_SND:
289 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
290
291 if (!!test_bit(code, dev->snd) != !!value)
292 __change_bit(code, dev->snd);
293 disposition = INPUT_PASS_TO_ALL;
294 }
295 break;
296
297 case EV_REP:
298 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
299 dev->rep[code] = value;
300 disposition = INPUT_PASS_TO_ALL;
301 }
302 break;
303
304 case EV_FF:
305 if (value >= 0)
306 disposition = INPUT_PASS_TO_ALL;
307 break;
308
309 case EV_PWR:
310 disposition = INPUT_PASS_TO_ALL;
311 break;
312 }
313
314 *pval = value;
315 return disposition;
316}
317
318static void input_event_dispose(struct input_dev *dev, int disposition,
319 unsigned int type, unsigned int code, int value)
320{
321 if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
322 dev->event(dev, type, code, value);
323
324 if (disposition & INPUT_PASS_TO_HANDLERS) {
325 struct input_value *v;
326
327 if (disposition & INPUT_SLOT) {
328 v = &dev->vals[dev->num_vals++];
329 v->type = EV_ABS;
330 v->code = ABS_MT_SLOT;
331 v->value = dev->mt->slot;
332 }
333
334 v = &dev->vals[dev->num_vals++];
335 v->type = type;
336 v->code = code;
337 v->value = value;
338 }
339
340 if (disposition & INPUT_FLUSH) {
341 if (dev->num_vals >= 2)
342 input_pass_values(dev, dev->vals, dev->num_vals);
343 dev->num_vals = 0;
344 /*
345 * Reset the timestamp on flush so we won't end up
346 * with a stale one. Note we only need to reset the
347 * monolithic one as we use its presence when deciding
348 * whether to generate a synthetic timestamp.
349 */
350 dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
351 } else if (dev->num_vals >= dev->max_vals - 2) {
352 dev->vals[dev->num_vals++] = input_value_sync;
353 input_pass_values(dev, dev->vals, dev->num_vals);
354 dev->num_vals = 0;
355 }
356}
357
358void input_handle_event(struct input_dev *dev,
359 unsigned int type, unsigned int code, int value)
360{
361 int disposition;
362
363 lockdep_assert_held(&dev->event_lock);
364
365 disposition = input_get_disposition(dev, type, code, &value);
366 if (disposition != INPUT_IGNORE_EVENT) {
367 if (type != EV_SYN)
368 add_input_randomness(type, code, value);
369
370 input_event_dispose(dev, disposition, type, code, value);
371 }
372}
373
374/**
375 * input_event() - report new input event
376 * @dev: device that generated the event
377 * @type: type of the event
378 * @code: event code
379 * @value: value of the event
380 *
381 * This function should be used by drivers implementing various input
382 * devices to report input events. See also input_inject_event().
383 *
384 * NOTE: input_event() may be safely used right after input device was
385 * allocated with input_allocate_device(), even before it is registered
386 * with input_register_device(), but the event will not reach any of the
387 * input handlers. Such early invocation of input_event() may be used
388 * to 'seed' initial state of a switch or initial position of absolute
389 * axis, etc.
390 */
391void input_event(struct input_dev *dev,
392 unsigned int type, unsigned int code, int value)
393{
394 if (is_event_supported(type, dev->evbit, EV_MAX)) {
395 guard(spinlock_irqsave)(&dev->event_lock);
396 input_handle_event(dev, type, code, value);
397 }
398}
399EXPORT_SYMBOL(input_event);
400
401/**
402 * input_inject_event() - send input event from input handler
403 * @handle: input handle to send event through
404 * @type: type of the event
405 * @code: event code
406 * @value: value of the event
407 *
408 * Similar to input_event() but will ignore event if device is
409 * "grabbed" and handle injecting event is not the one that owns
410 * the device.
411 */
412void input_inject_event(struct input_handle *handle,
413 unsigned int type, unsigned int code, int value)
414{
415 struct input_dev *dev = handle->dev;
416 struct input_handle *grab;
417
418 if (is_event_supported(type, dev->evbit, EV_MAX)) {
419 guard(spinlock_irqsave)(&dev->event_lock);
420 guard(rcu)();
421
422 grab = rcu_dereference(dev->grab);
423 if (!grab || grab == handle)
424 input_handle_event(dev, type, code, value);
425
426 }
427}
428EXPORT_SYMBOL(input_inject_event);
429
430/**
431 * input_alloc_absinfo - allocates array of input_absinfo structs
432 * @dev: the input device emitting absolute events
433 *
434 * If the absinfo struct the caller asked for is already allocated, this
435 * functions will not do anything.
436 */
437void input_alloc_absinfo(struct input_dev *dev)
438{
439 if (dev->absinfo)
440 return;
441
442 dev->absinfo = kzalloc_objs(*dev->absinfo, ABS_CNT);
443 if (!dev->absinfo) {
444 dev_err(dev->dev.parent ?: &dev->dev,
445 "%s: unable to allocate memory\n", __func__);
446 /*
447 * We will handle this allocation failure in
448 * input_register_device() when we refuse to register input
449 * device with ABS bits but without absinfo.
450 */
451 }
452}
453EXPORT_SYMBOL(input_alloc_absinfo);
454
455void input_set_abs_params(struct input_dev *dev, unsigned int axis,
456 int min, int max, int fuzz, int flat)
457{
458 struct input_absinfo *absinfo;
459
460 __set_bit(EV_ABS, dev->evbit);
461 __set_bit(axis, dev->absbit);
462
463 input_alloc_absinfo(dev);
464 if (!dev->absinfo)
465 return;
466
467 absinfo = &dev->absinfo[axis];
468 absinfo->minimum = min;
469 absinfo->maximum = max;
470 absinfo->fuzz = fuzz;
471 absinfo->flat = flat;
472}
473EXPORT_SYMBOL(input_set_abs_params);
474
475/**
476 * input_copy_abs - Copy absinfo from one input_dev to another
477 * @dst: Destination input device to copy the abs settings to
478 * @dst_axis: ABS_* value selecting the destination axis
479 * @src: Source input device to copy the abs settings from
480 * @src_axis: ABS_* value selecting the source axis
481 *
482 * Set absinfo for the selected destination axis by copying it from
483 * the specified source input device's source axis.
484 * This is useful to e.g. setup a pen/stylus input-device for combined
485 * touchscreen/pen hardware where the pen uses the same coordinates as
486 * the touchscreen.
487 */
488void input_copy_abs(struct input_dev *dst, unsigned int dst_axis,
489 const struct input_dev *src, unsigned int src_axis)
490{
491 /* src must have EV_ABS and src_axis set */
492 if (WARN_ON(!(test_bit(EV_ABS, src->evbit) &&
493 test_bit(src_axis, src->absbit))))
494 return;
495
496 /*
497 * input_alloc_absinfo() may have failed for the source. Our caller is
498 * expected to catch this when registering the input devices, which may
499 * happen after the input_copy_abs() call.
500 */
501 if (!src->absinfo)
502 return;
503
504 input_set_capability(dst, EV_ABS, dst_axis);
505 if (!dst->absinfo)
506 return;
507
508 dst->absinfo[dst_axis] = src->absinfo[src_axis];
509}
510EXPORT_SYMBOL(input_copy_abs);
511
512/**
513 * input_grab_device - grabs device for exclusive use
514 * @handle: input handle that wants to own the device
515 *
516 * When a device is grabbed by an input handle all events generated by
517 * the device are delivered only to this handle. Also events injected
518 * by other input handles are ignored while device is grabbed.
519 */
520int input_grab_device(struct input_handle *handle)
521{
522 struct input_dev *dev = handle->dev;
523
524 scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
525 if (dev->grab)
526 return -EBUSY;
527
528 rcu_assign_pointer(dev->grab, handle);
529 }
530
531 return 0;
532}
533EXPORT_SYMBOL(input_grab_device);
534
535static void __input_release_device(struct input_handle *handle)
536{
537 struct input_dev *dev = handle->dev;
538 struct input_handle *grabber;
539
540 grabber = rcu_dereference_protected(dev->grab,
541 lockdep_is_held(&dev->mutex));
542 if (grabber == handle) {
543 rcu_assign_pointer(dev->grab, NULL);
544 /* Make sure input_pass_values() notices that grab is gone */
545 synchronize_rcu();
546
547 list_for_each_entry(handle, &dev->h_list, d_node)
548 if (handle->open && handle->handler->start)
549 handle->handler->start(handle);
550 }
551}
552
553/**
554 * input_release_device - release previously grabbed device
555 * @handle: input handle that owns the device
556 *
557 * Releases previously grabbed device so that other input handles can
558 * start receiving input events. Upon release all handlers attached
559 * to the device have their start() method called so they have a change
560 * to synchronize device state with the rest of the system.
561 */
562void input_release_device(struct input_handle *handle)
563{
564 struct input_dev *dev = handle->dev;
565
566 guard(mutex)(&dev->mutex);
567 __input_release_device(handle);
568}
569EXPORT_SYMBOL(input_release_device);
570
571/**
572 * input_open_device - open input device
573 * @handle: handle through which device is being accessed
574 *
575 * This function should be called by input handlers when they
576 * want to start receive events from given input device.
577 */
578int input_open_device(struct input_handle *handle)
579{
580 struct input_dev *dev = handle->dev;
581 int error;
582
583 scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
584 if (dev->going_away)
585 return -ENODEV;
586
587 handle->open++;
588
589 if (handle->handler->passive_observer)
590 return 0;
591
592 if (dev->users++ || dev->inhibited) {
593 /*
594 * Device is already opened and/or inhibited,
595 * so we can exit immediately and report success.
596 */
597 return 0;
598 }
599
600 if (dev->open) {
601 error = dev->open(dev);
602 if (error) {
603 dev->users--;
604 handle->open--;
605 /*
606 * Make sure we are not delivering any more
607 * events through this handle.
608 */
609 synchronize_rcu();
610 return error;
611 }
612 }
613
614 if (dev->poller)
615 input_dev_poller_start(dev->poller);
616 }
617
618 return 0;
619}
620EXPORT_SYMBOL(input_open_device);
621
622int input_flush_device(struct input_handle *handle, struct file *file)
623{
624 struct input_dev *dev = handle->dev;
625
626 scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
627 if (dev->flush)
628 return dev->flush(dev, file);
629 }
630
631 return 0;
632}
633EXPORT_SYMBOL(input_flush_device);
634
635/**
636 * input_close_device - close input device
637 * @handle: handle through which device is being accessed
638 *
639 * This function should be called by input handlers when they
640 * want to stop receive events from given input device.
641 */
642void input_close_device(struct input_handle *handle)
643{
644 struct input_dev *dev = handle->dev;
645
646 guard(mutex)(&dev->mutex);
647
648 __input_release_device(handle);
649
650 if (!handle->handler->passive_observer) {
651 if (!--dev->users && !dev->inhibited) {
652 if (dev->poller)
653 input_dev_poller_stop(dev->poller);
654 if (dev->close)
655 dev->close(dev);
656 }
657 }
658
659 if (!--handle->open) {
660 /*
661 * synchronize_rcu() makes sure that input_pass_values()
662 * completed and that no more input events are delivered
663 * through this handle
664 */
665 synchronize_rcu();
666 }
667}
668EXPORT_SYMBOL(input_close_device);
669
670/*
671 * Simulate keyup events for all keys that are marked as pressed.
672 * The function must be called with dev->event_lock held.
673 */
674static bool input_dev_release_keys(struct input_dev *dev)
675{
676 bool need_sync = false;
677 int code;
678
679 lockdep_assert_held(&dev->event_lock);
680
681 if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
682 for_each_set_bit(code, dev->key, KEY_CNT) {
683 input_handle_event(dev, EV_KEY, code, 0);
684 need_sync = true;
685 }
686 }
687
688 return need_sync;
689}
690
691/*
692 * Prepare device for unregistering
693 */
694static void input_disconnect_device(struct input_dev *dev)
695{
696 struct input_handle *handle;
697
698 /*
699 * Mark device as going away. Note that we take dev->mutex here
700 * not to protect access to dev->going_away but rather to ensure
701 * that there are no threads in the middle of input_open_device()
702 */
703 scoped_guard(mutex, &dev->mutex)
704 dev->going_away = true;
705
706 guard(spinlock_irq)(&dev->event_lock);
707
708 /*
709 * Simulate keyup events for all pressed keys so that handlers
710 * are not left with "stuck" keys. The driver may continue
711 * generate events even after we done here but they will not
712 * reach any handlers.
713 */
714 if (input_dev_release_keys(dev))
715 input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
716
717 list_for_each_entry(handle, &dev->h_list, d_node)
718 handle->open = 0;
719}
720
721/**
722 * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
723 * @ke: keymap entry containing scancode to be converted.
724 * @scancode: pointer to the location where converted scancode should
725 * be stored.
726 *
727 * This function is used to convert scancode stored in &struct keymap_entry
728 * into scalar form understood by legacy keymap handling methods. These
729 * methods expect scancodes to be represented as 'unsigned int'.
730 */
731int input_scancode_to_scalar(const struct input_keymap_entry *ke,
732 unsigned int *scancode)
733{
734 switch (ke->len) {
735 case 1:
736 *scancode = *((u8 *)ke->scancode);
737 break;
738
739 case 2:
740 *scancode = *((u16 *)ke->scancode);
741 break;
742
743 case 4:
744 *scancode = *((u32 *)ke->scancode);
745 break;
746
747 default:
748 return -EINVAL;
749 }
750
751 return 0;
752}
753EXPORT_SYMBOL(input_scancode_to_scalar);
754
755/*
756 * Those routines handle the default case where no [gs]etkeycode() is
757 * defined. In this case, an array indexed by the scancode is used.
758 */
759
760static unsigned int input_fetch_keycode(struct input_dev *dev,
761 unsigned int index)
762{
763 switch (dev->keycodesize) {
764 case 1:
765 return ((u8 *)dev->keycode)[index];
766
767 case 2:
768 return ((u16 *)dev->keycode)[index];
769
770 default:
771 return ((u32 *)dev->keycode)[index];
772 }
773}
774
775static int input_default_getkeycode(struct input_dev *dev,
776 struct input_keymap_entry *ke)
777{
778 unsigned int index;
779 int error;
780
781 if (!dev->keycodesize)
782 return -EINVAL;
783
784 if (ke->flags & INPUT_KEYMAP_BY_INDEX)
785 index = ke->index;
786 else {
787 error = input_scancode_to_scalar(ke, &index);
788 if (error)
789 return error;
790 }
791
792 if (index >= dev->keycodemax)
793 return -EINVAL;
794
795 ke->keycode = input_fetch_keycode(dev, index);
796 ke->index = index;
797 ke->len = sizeof(index);
798 memcpy(ke->scancode, &index, sizeof(index));
799
800 return 0;
801}
802
803/**
804 * input_default_setkeycode - default setkeycode method
805 * @dev: input device which keymap is being updated.
806 * @ke: new keymap entry.
807 * @old_keycode: pointer to the location where old keycode should be stored.
808 *
809 * This function is the default implementation of &input_dev.setkeycode()
810 * method. It is typically used when a driver does not provide its own
811 * implementation, but it is also exported so drivers can extend it.
812 *
813 * The function must be called with &input_dev.event_lock held.
814 *
815 * Return: 0 on success, or a negative error code on failure.
816 */
817int input_default_setkeycode(struct input_dev *dev,
818 const struct input_keymap_entry *ke,
819 unsigned int *old_keycode)
820{
821 unsigned int index;
822 int error;
823 int i;
824
825 lockdep_assert_held(&dev->event_lock);
826
827 if (!dev->keycodesize)
828 return -EINVAL;
829
830 if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
831 index = ke->index;
832 } else {
833 error = input_scancode_to_scalar(ke, &index);
834 if (error)
835 return error;
836 }
837
838 if (index >= dev->keycodemax)
839 return -EINVAL;
840
841 if (dev->keycodesize < sizeof(ke->keycode) &&
842 (ke->keycode >> (dev->keycodesize * 8)))
843 return -EINVAL;
844
845 switch (dev->keycodesize) {
846 case 1: {
847 u8 *k = (u8 *)dev->keycode;
848 *old_keycode = k[index];
849 k[index] = ke->keycode;
850 break;
851 }
852 case 2: {
853 u16 *k = (u16 *)dev->keycode;
854 *old_keycode = k[index];
855 k[index] = ke->keycode;
856 break;
857 }
858 default: {
859 u32 *k = (u32 *)dev->keycode;
860 *old_keycode = k[index];
861 k[index] = ke->keycode;
862 break;
863 }
864 }
865
866 if (*old_keycode <= KEY_MAX) {
867 __clear_bit(*old_keycode, dev->keybit);
868 for (i = 0; i < dev->keycodemax; i++) {
869 if (input_fetch_keycode(dev, i) == *old_keycode) {
870 __set_bit(*old_keycode, dev->keybit);
871 /* Setting the bit twice is useless, so break */
872 break;
873 }
874 }
875 }
876
877 __set_bit(ke->keycode, dev->keybit);
878 return 0;
879}
880EXPORT_SYMBOL(input_default_setkeycode);
881
882/**
883 * input_get_keycode - retrieve keycode currently mapped to a given scancode
884 * @dev: input device which keymap is being queried
885 * @ke: keymap entry
886 *
887 * This function should be called by anyone interested in retrieving current
888 * keymap. Presently evdev handlers use it.
889 */
890int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
891{
892 guard(spinlock_irqsave)(&dev->event_lock);
893
894 return dev->getkeycode(dev, ke);
895}
896EXPORT_SYMBOL(input_get_keycode);
897
898/**
899 * input_set_keycode - attribute a keycode to a given scancode
900 * @dev: input device which keymap is being updated
901 * @ke: new keymap entry
902 *
903 * This function should be called by anyone needing to update current
904 * keymap. Presently keyboard and evdev handlers use it.
905 */
906int input_set_keycode(struct input_dev *dev,
907 const struct input_keymap_entry *ke)
908{
909 unsigned int old_keycode;
910 int error;
911
912 if (ke->keycode > KEY_MAX)
913 return -EINVAL;
914
915 guard(spinlock_irqsave)(&dev->event_lock);
916
917 error = dev->setkeycode(dev, ke, &old_keycode);
918 if (error)
919 return error;
920
921 /* Make sure KEY_RESERVED did not get enabled. */
922 __clear_bit(KEY_RESERVED, dev->keybit);
923
924 /*
925 * Simulate keyup event if keycode is not present
926 * in the keymap anymore
927 */
928 if (old_keycode > KEY_MAX) {
929 dev_warn(dev->dev.parent ?: &dev->dev,
930 "%s: got too big old keycode %#x\n",
931 __func__, old_keycode);
932 } else if (test_bit(EV_KEY, dev->evbit) &&
933 !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
934 __test_and_clear_bit(old_keycode, dev->key)) {
935 /*
936 * We have to use input_event_dispose() here directly instead
937 * of input_handle_event() because the key we want to release
938 * here is considered no longer supported by the device and
939 * input_handle_event() will ignore it.
940 */
941 input_event_dispose(dev, INPUT_PASS_TO_HANDLERS,
942 EV_KEY, old_keycode, 0);
943 input_event_dispose(dev, INPUT_PASS_TO_HANDLERS | INPUT_FLUSH,
944 EV_SYN, SYN_REPORT, 1);
945 }
946
947 return 0;
948}
949EXPORT_SYMBOL(input_set_keycode);
950
951bool input_match_device_id(const struct input_dev *dev,
952 const struct input_device_id *id)
953{
954 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
955 if (id->bustype != dev->id.bustype)
956 return false;
957
958 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
959 if (id->vendor != dev->id.vendor)
960 return false;
961
962 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
963 if (id->product != dev->id.product)
964 return false;
965
966 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
967 if (id->version != dev->id.version)
968 return false;
969
970 if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
971 !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
972 !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
973 !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
974 !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
975 !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
976 !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
977 !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
978 !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
979 !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
980 return false;
981 }
982
983 return true;
984}
985EXPORT_SYMBOL(input_match_device_id);
986
987static const struct input_device_id *input_match_device(struct input_handler *handler,
988 struct input_dev *dev)
989{
990 const struct input_device_id *id;
991
992 for (id = handler->id_table; id->flags; id++) {
993 if (input_match_device_id(dev, id) &&
994 (!handler->match || handler->match(handler, dev))) {
995 return id;
996 }
997 }
998
999 return NULL;
1000}
1001
1002static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1003{
1004 const struct input_device_id *id;
1005 int error;
1006
1007 id = input_match_device(handler, dev);
1008 if (!id)
1009 return -ENODEV;
1010
1011 error = handler->connect(handler, dev, id);
1012 if (error && error != -ENODEV)
1013 pr_err("failed to attach handler %s to device %s, error: %d\n",
1014 handler->name, kobject_name(&dev->dev.kobj), error);
1015
1016 return error;
1017}
1018
1019#ifdef CONFIG_PROC_FS
1020
1021static struct proc_dir_entry *proc_bus_input_dir;
1022static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1023static int input_devices_state;
1024
1025static inline void input_wakeup_procfs_readers(void)
1026{
1027 input_devices_state++;
1028 wake_up(&input_devices_poll_wait);
1029}
1030
1031struct input_seq_state {
1032 unsigned short pos;
1033 bool mutex_acquired;
1034 int input_devices_state;
1035};
1036
1037static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1038{
1039 struct seq_file *seq = file->private_data;
1040 struct input_seq_state *state = seq->private;
1041
1042 poll_wait(file, &input_devices_poll_wait, wait);
1043 if (state->input_devices_state != input_devices_state) {
1044 state->input_devices_state = input_devices_state;
1045 return EPOLLIN | EPOLLRDNORM;
1046 }
1047
1048 return 0;
1049}
1050
1051static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1052{
1053 struct input_seq_state *state = seq->private;
1054 int error;
1055
1056 error = mutex_lock_interruptible(&input_mutex);
1057 if (error) {
1058 state->mutex_acquired = false;
1059 return ERR_PTR(error);
1060 }
1061
1062 state->mutex_acquired = true;
1063
1064 return seq_list_start(&input_dev_list, *pos);
1065}
1066
1067static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1068{
1069 return seq_list_next(v, &input_dev_list, pos);
1070}
1071
1072static void input_seq_stop(struct seq_file *seq, void *v)
1073{
1074 struct input_seq_state *state = seq->private;
1075
1076 if (state->mutex_acquired)
1077 mutex_unlock(&input_mutex);
1078}
1079
1080static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1081 unsigned long *bitmap, int max)
1082{
1083 int i;
1084 bool skip_empty = true;
1085 char buf[18];
1086
1087 seq_printf(seq, "B: %s=", name);
1088
1089 for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1090 if (input_bits_to_string(buf, sizeof(buf),
1091 bitmap[i], skip_empty)) {
1092 skip_empty = false;
1093 seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1094 }
1095 }
1096
1097 /*
1098 * If no output was produced print a single 0.
1099 */
1100 if (skip_empty)
1101 seq_putc(seq, '0');
1102
1103 seq_putc(seq, '\n');
1104}
1105
1106static int input_devices_seq_show(struct seq_file *seq, void *v)
1107{
1108 struct input_dev *dev = container_of(v, struct input_dev, node);
1109 const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1110 struct input_handle *handle;
1111
1112 seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1113 dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1114
1115 seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1116 seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1117 seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1118 seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1119 seq_puts(seq, "H: Handlers=");
1120
1121 list_for_each_entry(handle, &dev->h_list, d_node)
1122 seq_printf(seq, "%s ", handle->name);
1123 seq_putc(seq, '\n');
1124
1125 input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1126
1127 input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1128 if (test_bit(EV_KEY, dev->evbit))
1129 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1130 if (test_bit(EV_REL, dev->evbit))
1131 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1132 if (test_bit(EV_ABS, dev->evbit))
1133 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1134 if (test_bit(EV_MSC, dev->evbit))
1135 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1136 if (test_bit(EV_LED, dev->evbit))
1137 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1138 if (test_bit(EV_SND, dev->evbit))
1139 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1140 if (test_bit(EV_FF, dev->evbit))
1141 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1142 if (test_bit(EV_SW, dev->evbit))
1143 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1144
1145 seq_putc(seq, '\n');
1146
1147 kfree(path);
1148 return 0;
1149}
1150
1151static const struct seq_operations input_devices_seq_ops = {
1152 .start = input_devices_seq_start,
1153 .next = input_devices_seq_next,
1154 .stop = input_seq_stop,
1155 .show = input_devices_seq_show,
1156};
1157
1158static int input_proc_devices_open(struct inode *inode, struct file *file)
1159{
1160 return seq_open_private(file, &input_devices_seq_ops,
1161 sizeof(struct input_seq_state));
1162}
1163
1164static const struct proc_ops input_devices_proc_ops = {
1165 .proc_open = input_proc_devices_open,
1166 .proc_poll = input_proc_devices_poll,
1167 .proc_read = seq_read,
1168 .proc_lseek = seq_lseek,
1169 .proc_release = seq_release_private,
1170};
1171
1172static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1173{
1174 struct input_seq_state *state = seq->private;
1175 int error;
1176
1177 error = mutex_lock_interruptible(&input_mutex);
1178 if (error) {
1179 state->mutex_acquired = false;
1180 return ERR_PTR(error);
1181 }
1182
1183 state->mutex_acquired = true;
1184 state->pos = *pos;
1185
1186 return seq_list_start(&input_handler_list, *pos);
1187}
1188
1189static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1190{
1191 struct input_seq_state *state = seq->private;
1192
1193 state->pos = *pos + 1;
1194 return seq_list_next(v, &input_handler_list, pos);
1195}
1196
1197static int input_handlers_seq_show(struct seq_file *seq, void *v)
1198{
1199 struct input_handler *handler = container_of(v, struct input_handler, node);
1200 struct input_seq_state *state = seq->private;
1201
1202 seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1203 if (handler->filter)
1204 seq_puts(seq, " (filter)");
1205 if (handler->legacy_minors)
1206 seq_printf(seq, " Minor=%d", handler->minor);
1207 seq_putc(seq, '\n');
1208
1209 return 0;
1210}
1211
1212static const struct seq_operations input_handlers_seq_ops = {
1213 .start = input_handlers_seq_start,
1214 .next = input_handlers_seq_next,
1215 .stop = input_seq_stop,
1216 .show = input_handlers_seq_show,
1217};
1218
1219static int input_proc_handlers_open(struct inode *inode, struct file *file)
1220{
1221 return seq_open_private(file, &input_handlers_seq_ops,
1222 sizeof(struct input_seq_state));
1223}
1224
1225static const struct proc_ops input_handlers_proc_ops = {
1226 .proc_open = input_proc_handlers_open,
1227 .proc_read = seq_read,
1228 .proc_lseek = seq_lseek,
1229 .proc_release = seq_release_private,
1230};
1231
1232static int __init input_proc_init(void)
1233{
1234 struct proc_dir_entry *entry;
1235
1236 proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1237 if (!proc_bus_input_dir)
1238 return -ENOMEM;
1239
1240 entry = proc_create("devices", 0, proc_bus_input_dir,
1241 &input_devices_proc_ops);
1242 if (!entry)
1243 goto fail1;
1244
1245 entry = proc_create("handlers", 0, proc_bus_input_dir,
1246 &input_handlers_proc_ops);
1247 if (!entry)
1248 goto fail2;
1249
1250 return 0;
1251
1252 fail2: remove_proc_entry("devices", proc_bus_input_dir);
1253 fail1: remove_proc_entry("bus/input", NULL);
1254 return -ENOMEM;
1255}
1256
1257static void input_proc_exit(void)
1258{
1259 remove_proc_entry("devices", proc_bus_input_dir);
1260 remove_proc_entry("handlers", proc_bus_input_dir);
1261 remove_proc_entry("bus/input", NULL);
1262}
1263
1264#else /* !CONFIG_PROC_FS */
1265static inline void input_wakeup_procfs_readers(void) { }
1266static inline int input_proc_init(void) { return 0; }
1267static inline void input_proc_exit(void) { }
1268#endif
1269
1270#define INPUT_DEV_STRING_ATTR_SHOW(name) \
1271static ssize_t input_dev_show_##name(struct device *dev, \
1272 struct device_attribute *attr, \
1273 char *buf) \
1274{ \
1275 struct input_dev *input_dev = to_input_dev(dev); \
1276 \
1277 return sysfs_emit(buf, "%s\n", \
1278 input_dev->name ? input_dev->name : ""); \
1279} \
1280static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1281
1282INPUT_DEV_STRING_ATTR_SHOW(name);
1283INPUT_DEV_STRING_ATTR_SHOW(phys);
1284INPUT_DEV_STRING_ATTR_SHOW(uniq);
1285
1286static int input_print_modalias_bits(char *buf, int size,
1287 char name, const unsigned long *bm,
1288 unsigned int min_bit, unsigned int max_bit)
1289{
1290 int bit = min_bit;
1291 int len = 0;
1292
1293 len += snprintf(buf, max(size, 0), "%c", name);
1294 for_each_set_bit_from(bit, bm, max_bit)
1295 len += snprintf(buf + len, max(size - len, 0), "%X,", bit);
1296 return len;
1297}
1298
1299static int input_print_modalias_parts(char *buf, int size, int full_len,
1300 const struct input_dev *id)
1301{
1302 int len, klen, remainder, space;
1303
1304 len = snprintf(buf, max(size, 0),
1305 "input:b%04Xv%04Xp%04Xe%04X-",
1306 id->id.bustype, id->id.vendor,
1307 id->id.product, id->id.version);
1308
1309 len += input_print_modalias_bits(buf + len, size - len,
1310 'e', id->evbit, 0, EV_MAX);
1311
1312 /*
1313 * Calculate the remaining space in the buffer making sure we
1314 * have place for the terminating 0.
1315 */
1316 space = max(size - (len + 1), 0);
1317
1318 klen = input_print_modalias_bits(buf + len, size - len,
1319 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1320 len += klen;
1321
1322 /*
1323 * If we have more data than we can fit in the buffer, check
1324 * if we can trim key data to fit in the rest. We will indicate
1325 * that key data is incomplete by adding "+" sign at the end, like
1326 * this: * "k1,2,3,45,+,".
1327 *
1328 * Note that we shortest key info (if present) is "k+," so we
1329 * can only try to trim if key data is longer than that.
1330 */
1331 if (full_len && size < full_len + 1 && klen > 3) {
1332 remainder = full_len - len;
1333 /*
1334 * We can only trim if we have space for the remainder
1335 * and also for at least "k+," which is 3 more characters.
1336 */
1337 if (remainder <= space - 3) {
1338 /*
1339 * We are guaranteed to have 'k' in the buffer, so
1340 * we need at least 3 additional bytes for storing
1341 * "+," in addition to the remainder.
1342 */
1343 for (int i = size - 1 - remainder - 3; i >= 0; i--) {
1344 if (buf[i] == 'k' || buf[i] == ',') {
1345 strcpy(buf + i + 1, "+,");
1346 len = i + 3; /* Not counting '\0' */
1347 break;
1348 }
1349 }
1350 }
1351 }
1352
1353 len += input_print_modalias_bits(buf + len, size - len,
1354 'r', id->relbit, 0, REL_MAX);
1355 len += input_print_modalias_bits(buf + len, size - len,
1356 'a', id->absbit, 0, ABS_MAX);
1357 len += input_print_modalias_bits(buf + len, size - len,
1358 'm', id->mscbit, 0, MSC_MAX);
1359 len += input_print_modalias_bits(buf + len, size - len,
1360 'l', id->ledbit, 0, LED_MAX);
1361 len += input_print_modalias_bits(buf + len, size - len,
1362 's', id->sndbit, 0, SND_MAX);
1363 len += input_print_modalias_bits(buf + len, size - len,
1364 'f', id->ffbit, 0, FF_MAX);
1365 len += input_print_modalias_bits(buf + len, size - len,
1366 'w', id->swbit, 0, SW_MAX);
1367
1368 return len;
1369}
1370
1371static int input_print_modalias(char *buf, int size, const struct input_dev *id)
1372{
1373 int full_len;
1374
1375 /*
1376 * Printing is done in 2 passes: first one figures out total length
1377 * needed for the modalias string, second one will try to trim key
1378 * data in case when buffer is too small for the entire modalias.
1379 * If the buffer is too small regardless, it will fill as much as it
1380 * can (without trimming key data) into the buffer and leave it to
1381 * the caller to figure out what to do with the result.
1382 */
1383 full_len = input_print_modalias_parts(NULL, 0, 0, id);
1384 return input_print_modalias_parts(buf, size, full_len, id);
1385}
1386
1387static ssize_t input_dev_show_modalias(struct device *dev,
1388 struct device_attribute *attr,
1389 char *buf)
1390{
1391 struct input_dev *id = to_input_dev(dev);
1392 ssize_t len;
1393
1394 len = input_print_modalias(buf, PAGE_SIZE, id);
1395 if (len < PAGE_SIZE - 2)
1396 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1397
1398 return min_t(int, len, PAGE_SIZE);
1399}
1400static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1401
1402static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1403 int max, int add_cr);
1404
1405static ssize_t input_dev_show_properties(struct device *dev,
1406 struct device_attribute *attr,
1407 char *buf)
1408{
1409 struct input_dev *input_dev = to_input_dev(dev);
1410 int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1411 INPUT_PROP_MAX, true);
1412 return min_t(int, len, PAGE_SIZE);
1413}
1414static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1415
1416static int input_inhibit_device(struct input_dev *dev);
1417static int input_uninhibit_device(struct input_dev *dev);
1418
1419static ssize_t inhibited_show(struct device *dev,
1420 struct device_attribute *attr,
1421 char *buf)
1422{
1423 struct input_dev *input_dev = to_input_dev(dev);
1424
1425 return sysfs_emit(buf, "%d\n", input_dev->inhibited);
1426}
1427
1428static ssize_t inhibited_store(struct device *dev,
1429 struct device_attribute *attr, const char *buf,
1430 size_t len)
1431{
1432 struct input_dev *input_dev = to_input_dev(dev);
1433 ssize_t rv;
1434 bool inhibited;
1435
1436 if (kstrtobool(buf, &inhibited))
1437 return -EINVAL;
1438
1439 if (inhibited)
1440 rv = input_inhibit_device(input_dev);
1441 else
1442 rv = input_uninhibit_device(input_dev);
1443
1444 if (rv != 0)
1445 return rv;
1446
1447 return len;
1448}
1449
1450static DEVICE_ATTR_RW(inhibited);
1451
1452static struct attribute *input_dev_attrs[] = {
1453 &dev_attr_name.attr,
1454 &dev_attr_phys.attr,
1455 &dev_attr_uniq.attr,
1456 &dev_attr_modalias.attr,
1457 &dev_attr_properties.attr,
1458 &dev_attr_inhibited.attr,
1459 NULL
1460};
1461
1462static const struct attribute_group input_dev_attr_group = {
1463 .attrs = input_dev_attrs,
1464};
1465
1466#define INPUT_DEV_ID_ATTR(name) \
1467static ssize_t input_dev_show_id_##name(struct device *dev, \
1468 struct device_attribute *attr, \
1469 char *buf) \
1470{ \
1471 struct input_dev *input_dev = to_input_dev(dev); \
1472 return sysfs_emit(buf, "%04x\n", input_dev->id.name); \
1473} \
1474static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1475
1476INPUT_DEV_ID_ATTR(bustype);
1477INPUT_DEV_ID_ATTR(vendor);
1478INPUT_DEV_ID_ATTR(product);
1479INPUT_DEV_ID_ATTR(version);
1480
1481static struct attribute *input_dev_id_attrs[] = {
1482 &dev_attr_bustype.attr,
1483 &dev_attr_vendor.attr,
1484 &dev_attr_product.attr,
1485 &dev_attr_version.attr,
1486 NULL
1487};
1488
1489static const struct attribute_group input_dev_id_attr_group = {
1490 .name = "id",
1491 .attrs = input_dev_id_attrs,
1492};
1493
1494static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1495 int max, int add_cr)
1496{
1497 int i;
1498 int len = 0;
1499 bool skip_empty = true;
1500
1501 for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1502 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1503 bitmap[i], skip_empty);
1504 if (len) {
1505 skip_empty = false;
1506 if (i > 0)
1507 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1508 }
1509 }
1510
1511 /*
1512 * If no output was produced print a single 0.
1513 */
1514 if (len == 0)
1515 len = snprintf(buf, buf_size, "%d", 0);
1516
1517 if (add_cr)
1518 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1519
1520 return len;
1521}
1522
1523#define INPUT_DEV_CAP_ATTR(ev, bm) \
1524static ssize_t input_dev_show_cap_##bm(struct device *dev, \
1525 struct device_attribute *attr, \
1526 char *buf) \
1527{ \
1528 struct input_dev *input_dev = to_input_dev(dev); \
1529 int len = input_print_bitmap(buf, PAGE_SIZE, \
1530 input_dev->bm##bit, ev##_MAX, \
1531 true); \
1532 return min_t(int, len, PAGE_SIZE); \
1533} \
1534static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1535
1536INPUT_DEV_CAP_ATTR(EV, ev);
1537INPUT_DEV_CAP_ATTR(KEY, key);
1538INPUT_DEV_CAP_ATTR(REL, rel);
1539INPUT_DEV_CAP_ATTR(ABS, abs);
1540INPUT_DEV_CAP_ATTR(MSC, msc);
1541INPUT_DEV_CAP_ATTR(LED, led);
1542INPUT_DEV_CAP_ATTR(SND, snd);
1543INPUT_DEV_CAP_ATTR(FF, ff);
1544INPUT_DEV_CAP_ATTR(SW, sw);
1545
1546static struct attribute *input_dev_caps_attrs[] = {
1547 &dev_attr_ev.attr,
1548 &dev_attr_key.attr,
1549 &dev_attr_rel.attr,
1550 &dev_attr_abs.attr,
1551 &dev_attr_msc.attr,
1552 &dev_attr_led.attr,
1553 &dev_attr_snd.attr,
1554 &dev_attr_ff.attr,
1555 &dev_attr_sw.attr,
1556 NULL
1557};
1558
1559static const struct attribute_group input_dev_caps_attr_group = {
1560 .name = "capabilities",
1561 .attrs = input_dev_caps_attrs,
1562};
1563
1564static const struct attribute_group *input_dev_attr_groups[] = {
1565 &input_dev_attr_group,
1566 &input_dev_id_attr_group,
1567 &input_dev_caps_attr_group,
1568 &input_poller_attribute_group,
1569 NULL
1570};
1571
1572static void input_dev_release(struct device *device)
1573{
1574 struct input_dev *dev = to_input_dev(device);
1575
1576 input_ff_destroy(dev);
1577 input_mt_destroy_slots(dev);
1578 kfree(dev->poller);
1579 kfree(dev->absinfo);
1580 kfree(dev->vals);
1581 kfree(dev);
1582
1583 module_put(THIS_MODULE);
1584}
1585
1586/*
1587 * Input uevent interface - loading event handlers based on
1588 * device bitfields.
1589 */
1590static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1591 const char *name, const unsigned long *bitmap, int max)
1592{
1593 int len;
1594
1595 if (add_uevent_var(env, "%s", name))
1596 return -ENOMEM;
1597
1598 len = input_print_bitmap(&env->buf[env->buflen - 1],
1599 sizeof(env->buf) - env->buflen,
1600 bitmap, max, false);
1601 if (len >= (sizeof(env->buf) - env->buflen))
1602 return -ENOMEM;
1603
1604 env->buflen += len;
1605 return 0;
1606}
1607
1608/*
1609 * This is a pretty gross hack. When building uevent data the driver core
1610 * may try adding more environment variables to kobj_uevent_env without
1611 * telling us, so we have no idea how much of the buffer we can use to
1612 * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially
1613 * reduce amount of memory we will use for the modalias environment variable.
1614 *
1615 * The potential additions are:
1616 *
1617 * SEQNUM=18446744073709551615 - (%llu - 28 bytes)
1618 * HOME=/ (6 bytes)
1619 * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes)
1620 *
1621 * 68 bytes total. Allow extra buffer - 96 bytes
1622 */
1623#define UEVENT_ENV_EXTRA_LEN 96
1624
1625static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1626 const struct input_dev *dev)
1627{
1628 int len;
1629
1630 if (add_uevent_var(env, "MODALIAS="))
1631 return -ENOMEM;
1632
1633 len = input_print_modalias(&env->buf[env->buflen - 1],
1634 (int)sizeof(env->buf) - env->buflen -
1635 UEVENT_ENV_EXTRA_LEN,
1636 dev);
1637 if (len >= ((int)sizeof(env->buf) - env->buflen -
1638 UEVENT_ENV_EXTRA_LEN))
1639 return -ENOMEM;
1640
1641 env->buflen += len;
1642 return 0;
1643}
1644
1645#define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \
1646 do { \
1647 int err = add_uevent_var(env, fmt, val); \
1648 if (err) \
1649 return err; \
1650 } while (0)
1651
1652#define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \
1653 do { \
1654 int err = input_add_uevent_bm_var(env, name, bm, max); \
1655 if (err) \
1656 return err; \
1657 } while (0)
1658
1659#define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \
1660 do { \
1661 int err = input_add_uevent_modalias_var(env, dev); \
1662 if (err) \
1663 return err; \
1664 } while (0)
1665
1666static int input_dev_uevent(const struct device *device, struct kobj_uevent_env *env)
1667{
1668 const struct input_dev *dev = to_input_dev(device);
1669
1670 INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1671 dev->id.bustype, dev->id.vendor,
1672 dev->id.product, dev->id.version);
1673 if (dev->name)
1674 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1675 if (dev->phys)
1676 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1677 if (dev->uniq)
1678 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1679
1680 INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1681
1682 INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1683 if (test_bit(EV_KEY, dev->evbit))
1684 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1685 if (test_bit(EV_REL, dev->evbit))
1686 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1687 if (test_bit(EV_ABS, dev->evbit))
1688 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1689 if (test_bit(EV_MSC, dev->evbit))
1690 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1691 if (test_bit(EV_LED, dev->evbit))
1692 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1693 if (test_bit(EV_SND, dev->evbit))
1694 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1695 if (test_bit(EV_FF, dev->evbit))
1696 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1697 if (test_bit(EV_SW, dev->evbit))
1698 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1699
1700 INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1701
1702 return 0;
1703}
1704
1705#define INPUT_DO_TOGGLE(dev, type, bits, on) \
1706 do { \
1707 int i; \
1708 bool active; \
1709 \
1710 if (!test_bit(EV_##type, dev->evbit)) \
1711 break; \
1712 \
1713 for_each_set_bit(i, dev->bits##bit, type##_CNT) { \
1714 active = test_bit(i, dev->bits); \
1715 if (!active && !on) \
1716 continue; \
1717 \
1718 dev->event(dev, EV_##type, i, on ? active : 0); \
1719 } \
1720 } while (0)
1721
1722static void input_dev_toggle(struct input_dev *dev, bool activate)
1723{
1724 if (!dev->event)
1725 return;
1726
1727 INPUT_DO_TOGGLE(dev, LED, led, activate);
1728 INPUT_DO_TOGGLE(dev, SND, snd, activate);
1729
1730 if (activate && test_bit(EV_REP, dev->evbit)) {
1731 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1732 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1733 }
1734}
1735
1736/**
1737 * input_reset_device() - reset/restore the state of input device
1738 * @dev: input device whose state needs to be reset
1739 *
1740 * This function tries to reset the state of an opened input device and
1741 * bring internal state and state if the hardware in sync with each other.
1742 * We mark all keys as released, restore LED state, repeat rate, etc.
1743 */
1744void input_reset_device(struct input_dev *dev)
1745{
1746 guard(mutex)(&dev->mutex);
1747 guard(spinlock_irqsave)(&dev->event_lock);
1748
1749 input_dev_toggle(dev, true);
1750 if (input_dev_release_keys(dev))
1751 input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
1752}
1753EXPORT_SYMBOL(input_reset_device);
1754
1755static int input_inhibit_device(struct input_dev *dev)
1756{
1757 guard(mutex)(&dev->mutex);
1758
1759 if (dev->inhibited)
1760 return 0;
1761
1762 if (dev->users) {
1763 if (dev->close)
1764 dev->close(dev);
1765 if (dev->poller)
1766 input_dev_poller_stop(dev->poller);
1767 }
1768
1769 scoped_guard(spinlock_irq, &dev->event_lock) {
1770 input_mt_release_slots(dev);
1771 input_dev_release_keys(dev);
1772 input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
1773 input_dev_toggle(dev, false);
1774 }
1775
1776 dev->inhibited = true;
1777
1778 return 0;
1779}
1780
1781static int input_uninhibit_device(struct input_dev *dev)
1782{
1783 int error;
1784
1785 guard(mutex)(&dev->mutex);
1786
1787 if (!dev->inhibited)
1788 return 0;
1789
1790 if (dev->users) {
1791 if (dev->open) {
1792 error = dev->open(dev);
1793 if (error)
1794 return error;
1795 }
1796 if (dev->poller)
1797 input_dev_poller_start(dev->poller);
1798 }
1799
1800 dev->inhibited = false;
1801
1802 scoped_guard(spinlock_irq, &dev->event_lock)
1803 input_dev_toggle(dev, true);
1804
1805 return 0;
1806}
1807
1808static int input_dev_suspend(struct device *dev)
1809{
1810 struct input_dev *input_dev = to_input_dev(dev);
1811
1812 guard(spinlock_irq)(&input_dev->event_lock);
1813
1814 /*
1815 * Keys that are pressed now are unlikely to be
1816 * still pressed when we resume.
1817 */
1818 if (input_dev_release_keys(input_dev))
1819 input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
1820
1821 /* Turn off LEDs and sounds, if any are active. */
1822 input_dev_toggle(input_dev, false);
1823
1824 return 0;
1825}
1826
1827static int input_dev_resume(struct device *dev)
1828{
1829 struct input_dev *input_dev = to_input_dev(dev);
1830
1831 guard(spinlock_irq)(&input_dev->event_lock);
1832
1833 /* Restore state of LEDs and sounds, if any were active. */
1834 input_dev_toggle(input_dev, true);
1835
1836 return 0;
1837}
1838
1839static int input_dev_freeze(struct device *dev)
1840{
1841 struct input_dev *input_dev = to_input_dev(dev);
1842
1843 guard(spinlock_irq)(&input_dev->event_lock);
1844
1845 /*
1846 * Keys that are pressed now are unlikely to be
1847 * still pressed when we resume.
1848 */
1849 if (input_dev_release_keys(input_dev))
1850 input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
1851
1852 return 0;
1853}
1854
1855static int input_dev_poweroff(struct device *dev)
1856{
1857 struct input_dev *input_dev = to_input_dev(dev);
1858
1859 guard(spinlock_irq)(&input_dev->event_lock);
1860
1861 /* Turn off LEDs and sounds, if any are active. */
1862 input_dev_toggle(input_dev, false);
1863
1864 return 0;
1865}
1866
1867static const struct dev_pm_ops input_dev_pm_ops = {
1868 .suspend = input_dev_suspend,
1869 .resume = input_dev_resume,
1870 .freeze = input_dev_freeze,
1871 .poweroff = input_dev_poweroff,
1872 .restore = input_dev_resume,
1873};
1874
1875static const struct device_type input_dev_type = {
1876 .groups = input_dev_attr_groups,
1877 .release = input_dev_release,
1878 .uevent = input_dev_uevent,
1879 .pm = pm_sleep_ptr(&input_dev_pm_ops),
1880};
1881
1882static char *input_devnode(const struct device *dev, umode_t *mode)
1883{
1884 return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1885}
1886
1887const struct class input_class = {
1888 .name = "input",
1889 .devnode = input_devnode,
1890};
1891EXPORT_SYMBOL_GPL(input_class);
1892
1893/**
1894 * input_allocate_device - allocate memory for new input device
1895 *
1896 * Returns prepared struct input_dev or %NULL.
1897 *
1898 * NOTE: Use input_free_device() to free devices that have not been
1899 * registered; input_unregister_device() should be used for already
1900 * registered devices.
1901 */
1902struct input_dev *input_allocate_device(void)
1903{
1904 static atomic_t input_no = ATOMIC_INIT(-1);
1905 struct input_dev *dev;
1906
1907 dev = kzalloc_obj(*dev);
1908 if (!dev)
1909 return NULL;
1910
1911 /*
1912 * Start with space for SYN_REPORT + 7 EV_KEY/EV_MSC events + 2 spare,
1913 * see input_estimate_events_per_packet(). We will tune the number
1914 * when we register the device.
1915 */
1916 dev->max_vals = 10;
1917 dev->vals = kzalloc_objs(*dev->vals, dev->max_vals);
1918 if (!dev->vals) {
1919 kfree(dev);
1920 return NULL;
1921 }
1922
1923 mutex_init(&dev->mutex);
1924 spin_lock_init(&dev->event_lock);
1925 timer_setup(&dev->timer, NULL, 0);
1926 INIT_LIST_HEAD(&dev->h_list);
1927 INIT_LIST_HEAD(&dev->node);
1928
1929 dev->dev.type = &input_dev_type;
1930 dev->dev.class = &input_class;
1931 device_initialize(&dev->dev);
1932 /*
1933 * From this point on we can no longer simply "kfree(dev)", we need
1934 * to use input_free_device() so that device core properly frees its
1935 * resources associated with the input device.
1936 */
1937
1938 dev_set_name(&dev->dev, "input%lu",
1939 (unsigned long)atomic_inc_return(&input_no));
1940
1941 __module_get(THIS_MODULE);
1942
1943 return dev;
1944}
1945EXPORT_SYMBOL(input_allocate_device);
1946
1947struct input_devres {
1948 struct input_dev *input;
1949};
1950
1951static int devm_input_device_match(struct device *dev, void *res, void *data)
1952{
1953 struct input_devres *devres = res;
1954
1955 return devres->input == data;
1956}
1957
1958static void devm_input_device_release(struct device *dev, void *res)
1959{
1960 struct input_devres *devres = res;
1961 struct input_dev *input = devres->input;
1962
1963 dev_dbg(dev, "%s: dropping reference to %s\n",
1964 __func__, dev_name(&input->dev));
1965 input_put_device(input);
1966}
1967
1968/**
1969 * devm_input_allocate_device - allocate managed input device
1970 * @dev: device owning the input device being created
1971 *
1972 * Returns prepared struct input_dev or %NULL.
1973 *
1974 * Managed input devices do not need to be explicitly unregistered or
1975 * freed as it will be done automatically when owner device unbinds from
1976 * its driver (or binding fails). Once managed input device is allocated,
1977 * it is ready to be set up and registered in the same fashion as regular
1978 * input device. There are no special devm_input_device_[un]register()
1979 * variants, regular ones work with both managed and unmanaged devices,
1980 * should you need them. In most cases however, managed input device need
1981 * not be explicitly unregistered or freed.
1982 *
1983 * NOTE: the owner device is set up as parent of input device and users
1984 * should not override it.
1985 */
1986struct input_dev *devm_input_allocate_device(struct device *dev)
1987{
1988 struct input_dev *input;
1989 struct input_devres *devres;
1990
1991 devres = devres_alloc(devm_input_device_release,
1992 sizeof(*devres), GFP_KERNEL);
1993 if (!devres)
1994 return NULL;
1995
1996 input = input_allocate_device();
1997 if (!input) {
1998 devres_free(devres);
1999 return NULL;
2000 }
2001
2002 input->dev.parent = dev;
2003 input->devres_managed = true;
2004
2005 devres->input = input;
2006 devres_add(dev, devres);
2007
2008 return input;
2009}
2010EXPORT_SYMBOL(devm_input_allocate_device);
2011
2012/**
2013 * input_free_device - free memory occupied by input_dev structure
2014 * @dev: input device to free
2015 *
2016 * This function should only be used if input_register_device()
2017 * was not called yet or if it failed. Once device was registered
2018 * use input_unregister_device() and memory will be freed once last
2019 * reference to the device is dropped.
2020 *
2021 * Device should be allocated by input_allocate_device().
2022 *
2023 * NOTE: If there are references to the input device then memory
2024 * will not be freed until last reference is dropped.
2025 */
2026void input_free_device(struct input_dev *dev)
2027{
2028 if (dev) {
2029 if (dev->devres_managed)
2030 WARN_ON(devres_destroy(dev->dev.parent,
2031 devm_input_device_release,
2032 devm_input_device_match,
2033 dev));
2034 input_put_device(dev);
2035 }
2036}
2037EXPORT_SYMBOL(input_free_device);
2038
2039/**
2040 * input_set_timestamp - set timestamp for input events
2041 * @dev: input device to set timestamp for
2042 * @timestamp: the time at which the event has occurred
2043 * in CLOCK_MONOTONIC
2044 *
2045 * This function is intended to provide to the input system a more
2046 * accurate time of when an event actually occurred. The driver should
2047 * call this function as soon as a timestamp is acquired ensuring
2048 * clock conversions in input_set_timestamp are done correctly.
2049 *
2050 * The system entering suspend state between timestamp acquisition and
2051 * calling input_set_timestamp can result in inaccurate conversions.
2052 */
2053void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
2054{
2055 dev->timestamp[INPUT_CLK_MONO] = timestamp;
2056 dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
2057 dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
2058 TK_OFFS_BOOT);
2059}
2060EXPORT_SYMBOL(input_set_timestamp);
2061
2062/**
2063 * input_get_timestamp - get timestamp for input events
2064 * @dev: input device to get timestamp from
2065 *
2066 * A valid timestamp is a timestamp of non-zero value.
2067 */
2068ktime_t *input_get_timestamp(struct input_dev *dev)
2069{
2070 const ktime_t invalid_timestamp = ktime_set(0, 0);
2071
2072 if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
2073 input_set_timestamp(dev, ktime_get());
2074
2075 return dev->timestamp;
2076}
2077EXPORT_SYMBOL(input_get_timestamp);
2078
2079/**
2080 * input_set_capability - mark device as capable of a certain event
2081 * @dev: device that is capable of emitting or accepting event
2082 * @type: type of the event (EV_KEY, EV_REL, etc...)
2083 * @code: event code
2084 *
2085 * In addition to setting up corresponding bit in appropriate capability
2086 * bitmap the function also adjusts dev->evbit.
2087 */
2088void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
2089{
2090 if (type < EV_CNT && input_max_code[type] &&
2091 code > input_max_code[type]) {
2092 pr_err("%s: invalid code %u for type %u\n", __func__, code,
2093 type);
2094 dump_stack();
2095 return;
2096 }
2097
2098 switch (type) {
2099 case EV_KEY:
2100 __set_bit(code, dev->keybit);
2101 break;
2102
2103 case EV_REL:
2104 __set_bit(code, dev->relbit);
2105 break;
2106
2107 case EV_ABS:
2108 input_alloc_absinfo(dev);
2109 __set_bit(code, dev->absbit);
2110 break;
2111
2112 case EV_MSC:
2113 __set_bit(code, dev->mscbit);
2114 break;
2115
2116 case EV_SW:
2117 __set_bit(code, dev->swbit);
2118 break;
2119
2120 case EV_LED:
2121 __set_bit(code, dev->ledbit);
2122 break;
2123
2124 case EV_SND:
2125 __set_bit(code, dev->sndbit);
2126 break;
2127
2128 case EV_FF:
2129 __set_bit(code, dev->ffbit);
2130 break;
2131
2132 case EV_PWR:
2133 /* do nothing */
2134 break;
2135
2136 default:
2137 pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2138 dump_stack();
2139 return;
2140 }
2141
2142 __set_bit(type, dev->evbit);
2143}
2144EXPORT_SYMBOL(input_set_capability);
2145
2146static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2147{
2148 int mt_slots;
2149 int i;
2150 unsigned int events;
2151
2152 if (dev->mt) {
2153 mt_slots = dev->mt->num_slots;
2154 } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2155 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2156 dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1;
2157 mt_slots = clamp(mt_slots, 2, 32);
2158 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2159 mt_slots = 2;
2160 } else {
2161 mt_slots = 0;
2162 }
2163
2164 events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2165
2166 if (test_bit(EV_ABS, dev->evbit))
2167 for_each_set_bit(i, dev->absbit, ABS_CNT)
2168 events += input_is_mt_axis(i) ? mt_slots : 1;
2169
2170 if (test_bit(EV_REL, dev->evbit))
2171 events += bitmap_weight(dev->relbit, REL_CNT);
2172
2173 /* Make room for KEY and MSC events */
2174 events += 7;
2175
2176 return events;
2177}
2178
2179#define INPUT_CLEANSE_BITMASK(dev, type, bits) \
2180 do { \
2181 if (!test_bit(EV_##type, dev->evbit)) \
2182 memset(dev->bits##bit, 0, \
2183 sizeof(dev->bits##bit)); \
2184 } while (0)
2185
2186static void input_cleanse_bitmasks(struct input_dev *dev)
2187{
2188 INPUT_CLEANSE_BITMASK(dev, KEY, key);
2189 INPUT_CLEANSE_BITMASK(dev, REL, rel);
2190 INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2191 INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2192 INPUT_CLEANSE_BITMASK(dev, LED, led);
2193 INPUT_CLEANSE_BITMASK(dev, SND, snd);
2194 INPUT_CLEANSE_BITMASK(dev, FF, ff);
2195 INPUT_CLEANSE_BITMASK(dev, SW, sw);
2196}
2197
2198static void __input_unregister_device(struct input_dev *dev)
2199{
2200 struct input_handle *handle, *next;
2201
2202 input_disconnect_device(dev);
2203
2204 scoped_guard(mutex, &input_mutex) {
2205 list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2206 handle->handler->disconnect(handle);
2207 WARN_ON(!list_empty(&dev->h_list));
2208
2209 timer_delete_sync(&dev->timer);
2210 list_del_init(&dev->node);
2211
2212 input_wakeup_procfs_readers();
2213 }
2214
2215 device_del(&dev->dev);
2216}
2217
2218static void devm_input_device_unregister(struct device *dev, void *res)
2219{
2220 struct input_devres *devres = res;
2221 struct input_dev *input = devres->input;
2222
2223 dev_dbg(dev, "%s: unregistering device %s\n",
2224 __func__, dev_name(&input->dev));
2225 __input_unregister_device(input);
2226}
2227
2228/*
2229 * Generate software autorepeat event. Note that we take
2230 * dev->event_lock here to avoid racing with input_event
2231 * which may cause keys get "stuck".
2232 */
2233static void input_repeat_key(struct timer_list *t)
2234{
2235 struct input_dev *dev = timer_container_of(dev, t, timer);
2236
2237 guard(spinlock_irqsave)(&dev->event_lock);
2238
2239 if (!dev->inhibited &&
2240 test_bit(dev->repeat_key, dev->key) &&
2241 is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
2242
2243 input_set_timestamp(dev, ktime_get());
2244 input_handle_event(dev, EV_KEY, dev->repeat_key, 2);
2245 input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
2246
2247 if (dev->rep[REP_PERIOD])
2248 mod_timer(&dev->timer, jiffies +
2249 msecs_to_jiffies(dev->rep[REP_PERIOD]));
2250 }
2251}
2252
2253/**
2254 * input_enable_softrepeat - enable software autorepeat
2255 * @dev: input device
2256 * @delay: repeat delay
2257 * @period: repeat period
2258 *
2259 * Enable software autorepeat on the input device.
2260 */
2261void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2262{
2263 dev->timer.function = input_repeat_key;
2264 dev->rep[REP_DELAY] = delay;
2265 dev->rep[REP_PERIOD] = period;
2266}
2267EXPORT_SYMBOL(input_enable_softrepeat);
2268
2269bool input_device_enabled(struct input_dev *dev)
2270{
2271 lockdep_assert_held(&dev->mutex);
2272
2273 return !dev->inhibited && dev->users > 0;
2274}
2275EXPORT_SYMBOL_GPL(input_device_enabled);
2276
2277static int input_device_tune_vals(struct input_dev *dev)
2278{
2279 struct input_value *vals;
2280 unsigned int packet_size;
2281 unsigned int max_vals;
2282
2283 packet_size = input_estimate_events_per_packet(dev);
2284 if (dev->hint_events_per_packet < packet_size)
2285 dev->hint_events_per_packet = packet_size;
2286
2287 max_vals = dev->hint_events_per_packet + 2;
2288 if (dev->max_vals >= max_vals)
2289 return 0;
2290
2291 vals = kcalloc(max_vals, sizeof(*vals), GFP_KERNEL);
2292 if (!vals)
2293 return -ENOMEM;
2294
2295 scoped_guard(spinlock_irq, &dev->event_lock) {
2296 dev->max_vals = max_vals;
2297 swap(dev->vals, vals);
2298 }
2299
2300 /* Because of swap() above, this frees the old vals memory */
2301 kfree(vals);
2302
2303 return 0;
2304}
2305
2306/**
2307 * input_register_device - register device with input core
2308 * @dev: device to be registered
2309 *
2310 * This function registers device with input core. The device must be
2311 * allocated with input_allocate_device() and all it's capabilities
2312 * set up before registering.
2313 * If function fails the device must be freed with input_free_device().
2314 * Once device has been successfully registered it can be unregistered
2315 * with input_unregister_device(); input_free_device() should not be
2316 * called in this case.
2317 *
2318 * Note that this function is also used to register managed input devices
2319 * (ones allocated with devm_input_allocate_device()). Such managed input
2320 * devices need not be explicitly unregistered or freed, their tear down
2321 * is controlled by the devres infrastructure. It is also worth noting
2322 * that tear down of managed input devices is internally a 2-step process:
2323 * registered managed input device is first unregistered, but stays in
2324 * memory and can still handle input_event() calls (although events will
2325 * not be delivered anywhere). The freeing of managed input device will
2326 * happen later, when devres stack is unwound to the point where device
2327 * allocation was made.
2328 */
2329int input_register_device(struct input_dev *dev)
2330{
2331 struct input_devres *devres = NULL;
2332 struct input_handler *handler;
2333 const char *path;
2334 int error;
2335
2336 if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2337 dev_err(&dev->dev,
2338 "Absolute device without dev->absinfo, refusing to register\n");
2339 return -EINVAL;
2340 }
2341
2342 if (dev->devres_managed) {
2343 devres = devres_alloc(devm_input_device_unregister,
2344 sizeof(*devres), GFP_KERNEL);
2345 if (!devres)
2346 return -ENOMEM;
2347
2348 devres->input = dev;
2349 }
2350
2351 /* Every input device generates EV_SYN/SYN_REPORT events. */
2352 __set_bit(EV_SYN, dev->evbit);
2353
2354 /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2355 __clear_bit(KEY_RESERVED, dev->keybit);
2356
2357 /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2358 input_cleanse_bitmasks(dev);
2359
2360 error = input_device_tune_vals(dev);
2361 if (error)
2362 goto err_devres_free;
2363
2364 /*
2365 * If delay and period are pre-set by the driver, then autorepeating
2366 * is handled by the driver itself and we don't do it in input.c.
2367 */
2368 if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2369 input_enable_softrepeat(dev, 250, 33);
2370
2371 if (!dev->getkeycode)
2372 dev->getkeycode = input_default_getkeycode;
2373
2374 if (!dev->setkeycode)
2375 dev->setkeycode = input_default_setkeycode;
2376
2377 if (dev->poller)
2378 input_dev_poller_finalize(dev->poller);
2379
2380 error = device_add(&dev->dev);
2381 if (error)
2382 goto err_devres_free;
2383
2384 path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2385 pr_info("%s as %s\n",
2386 dev->name ? dev->name : "Unspecified device",
2387 path ? path : "N/A");
2388 kfree(path);
2389
2390 error = -EINTR;
2391 scoped_cond_guard(mutex_intr, goto err_device_del, &input_mutex) {
2392 list_add_tail(&dev->node, &input_dev_list);
2393
2394 list_for_each_entry(handler, &input_handler_list, node)
2395 input_attach_handler(dev, handler);
2396
2397 input_wakeup_procfs_readers();
2398 }
2399
2400 if (dev->devres_managed) {
2401 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2402 __func__, dev_name(&dev->dev));
2403 devres_add(dev->dev.parent, devres);
2404 }
2405 return 0;
2406
2407err_device_del:
2408 device_del(&dev->dev);
2409err_devres_free:
2410 devres_free(devres);
2411 return error;
2412}
2413EXPORT_SYMBOL(input_register_device);
2414
2415/**
2416 * input_unregister_device - unregister previously registered device
2417 * @dev: device to be unregistered
2418 *
2419 * This function unregisters an input device. Once device is unregistered
2420 * the caller should not try to access it as it may get freed at any moment.
2421 */
2422void input_unregister_device(struct input_dev *dev)
2423{
2424 if (dev->devres_managed) {
2425 WARN_ON(devres_destroy(dev->dev.parent,
2426 devm_input_device_unregister,
2427 devm_input_device_match,
2428 dev));
2429 __input_unregister_device(dev);
2430 /*
2431 * We do not do input_put_device() here because it will be done
2432 * when 2nd devres fires up.
2433 */
2434 } else {
2435 __input_unregister_device(dev);
2436 input_put_device(dev);
2437 }
2438}
2439EXPORT_SYMBOL(input_unregister_device);
2440
2441static int input_handler_check_methods(const struct input_handler *handler)
2442{
2443 int count = 0;
2444
2445 if (handler->filter)
2446 count++;
2447 if (handler->events)
2448 count++;
2449 if (handler->event)
2450 count++;
2451
2452 if (count > 1) {
2453 pr_err("%s: only one event processing method can be defined (%s)\n",
2454 __func__, handler->name);
2455 return -EINVAL;
2456 }
2457
2458 return 0;
2459}
2460
2461/**
2462 * input_register_handler - register a new input handler
2463 * @handler: handler to be registered
2464 *
2465 * This function registers a new input handler (interface) for input
2466 * devices in the system and attaches it to all input devices that
2467 * are compatible with the handler.
2468 */
2469int input_register_handler(struct input_handler *handler)
2470{
2471 struct input_dev *dev;
2472 int error;
2473
2474 error = input_handler_check_methods(handler);
2475 if (error)
2476 return error;
2477
2478 scoped_cond_guard(mutex_intr, return -EINTR, &input_mutex) {
2479 INIT_LIST_HEAD(&handler->h_list);
2480
2481 list_add_tail(&handler->node, &input_handler_list);
2482
2483 list_for_each_entry(dev, &input_dev_list, node)
2484 input_attach_handler(dev, handler);
2485
2486 input_wakeup_procfs_readers();
2487 }
2488
2489 return 0;
2490}
2491EXPORT_SYMBOL(input_register_handler);
2492
2493/**
2494 * input_unregister_handler - unregisters an input handler
2495 * @handler: handler to be unregistered
2496 *
2497 * This function disconnects a handler from its input devices and
2498 * removes it from lists of known handlers.
2499 */
2500void input_unregister_handler(struct input_handler *handler)
2501{
2502 struct input_handle *handle, *next;
2503
2504 guard(mutex)(&input_mutex);
2505
2506 list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2507 handler->disconnect(handle);
2508 WARN_ON(!list_empty(&handler->h_list));
2509
2510 list_del_init(&handler->node);
2511
2512 input_wakeup_procfs_readers();
2513}
2514EXPORT_SYMBOL(input_unregister_handler);
2515
2516/**
2517 * input_handler_for_each_handle - handle iterator
2518 * @handler: input handler to iterate
2519 * @data: data for the callback
2520 * @fn: function to be called for each handle
2521 *
2522 * Iterate over @bus's list of devices, and call @fn for each, passing
2523 * it @data and stop when @fn returns a non-zero value. The function is
2524 * using RCU to traverse the list and therefore may be using in atomic
2525 * contexts. The @fn callback is invoked from RCU critical section and
2526 * thus must not sleep.
2527 */
2528int input_handler_for_each_handle(struct input_handler *handler, void *data,
2529 int (*fn)(struct input_handle *, void *))
2530{
2531 struct input_handle *handle;
2532 int retval;
2533
2534 guard(rcu)();
2535
2536 list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2537 retval = fn(handle, data);
2538 if (retval)
2539 return retval;
2540 }
2541
2542 return 0;
2543}
2544EXPORT_SYMBOL(input_handler_for_each_handle);
2545
2546/*
2547 * An implementation of input_handle's handle_events() method that simply
2548 * invokes handler->event() method for each event one by one.
2549 */
2550static unsigned int input_handle_events_default(struct input_handle *handle,
2551 struct input_value *vals,
2552 unsigned int count)
2553{
2554 struct input_handler *handler = handle->handler;
2555 struct input_value *v;
2556
2557 for (v = vals; v != vals + count; v++)
2558 handler->event(handle, v->type, v->code, v->value);
2559
2560 return count;
2561}
2562
2563/*
2564 * An implementation of input_handle's handle_events() method that invokes
2565 * handler->filter() method for each event one by one and removes events
2566 * that were filtered out from the "vals" array.
2567 */
2568static unsigned int input_handle_events_filter(struct input_handle *handle,
2569 struct input_value *vals,
2570 unsigned int count)
2571{
2572 struct input_handler *handler = handle->handler;
2573 struct input_value *end = vals;
2574 struct input_value *v;
2575
2576 for (v = vals; v != vals + count; v++) {
2577 if (handler->filter(handle, v->type, v->code, v->value))
2578 continue;
2579 if (end != v)
2580 *end = *v;
2581 end++;
2582 }
2583
2584 return end - vals;
2585}
2586
2587/*
2588 * An implementation of input_handle's handle_events() method that does nothing.
2589 */
2590static unsigned int input_handle_events_null(struct input_handle *handle,
2591 struct input_value *vals,
2592 unsigned int count)
2593{
2594 return count;
2595}
2596
2597/*
2598 * Sets up appropriate handle->event_handler based on the input_handler
2599 * associated with the handle.
2600 */
2601static void input_handle_setup_event_handler(struct input_handle *handle)
2602{
2603 struct input_handler *handler = handle->handler;
2604
2605 if (handler->filter)
2606 handle->handle_events = input_handle_events_filter;
2607 else if (handler->event)
2608 handle->handle_events = input_handle_events_default;
2609 else if (handler->events)
2610 handle->handle_events = handler->events;
2611 else
2612 handle->handle_events = input_handle_events_null;
2613}
2614
2615/**
2616 * input_register_handle - register a new input handle
2617 * @handle: handle to register
2618 *
2619 * This function puts a new input handle onto device's
2620 * and handler's lists so that events can flow through
2621 * it once it is opened using input_open_device().
2622 *
2623 * This function is supposed to be called from handler's
2624 * connect() method.
2625 */
2626int input_register_handle(struct input_handle *handle)
2627{
2628 struct input_handler *handler = handle->handler;
2629 struct input_dev *dev = handle->dev;
2630
2631 input_handle_setup_event_handler(handle);
2632 /*
2633 * We take dev->mutex here to prevent race with
2634 * input_release_device().
2635 */
2636 scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
2637 /*
2638 * Filters go to the head of the list, normal handlers
2639 * to the tail.
2640 */
2641 if (handler->filter)
2642 list_add_rcu(&handle->d_node, &dev->h_list);
2643 else
2644 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2645 }
2646
2647 /*
2648 * Since we are supposed to be called from ->connect()
2649 * which is mutually exclusive with ->disconnect()
2650 * we can't be racing with input_unregister_handle()
2651 * and so separate lock is not needed here.
2652 */
2653 list_add_tail_rcu(&handle->h_node, &handler->h_list);
2654
2655 if (handler->start)
2656 handler->start(handle);
2657
2658 return 0;
2659}
2660EXPORT_SYMBOL(input_register_handle);
2661
2662/**
2663 * input_unregister_handle - unregister an input handle
2664 * @handle: handle to unregister
2665 *
2666 * This function removes input handle from device's
2667 * and handler's lists.
2668 *
2669 * This function is supposed to be called from handler's
2670 * disconnect() method.
2671 */
2672void input_unregister_handle(struct input_handle *handle)
2673{
2674 struct input_dev *dev = handle->dev;
2675
2676 list_del_rcu(&handle->h_node);
2677
2678 /*
2679 * Take dev->mutex to prevent race with input_release_device().
2680 */
2681 scoped_guard(mutex, &dev->mutex)
2682 list_del_rcu(&handle->d_node);
2683
2684 synchronize_rcu();
2685}
2686EXPORT_SYMBOL(input_unregister_handle);
2687
2688/**
2689 * input_get_new_minor - allocates a new input minor number
2690 * @legacy_base: beginning or the legacy range to be searched
2691 * @legacy_num: size of legacy range
2692 * @allow_dynamic: whether we can also take ID from the dynamic range
2693 *
2694 * This function allocates a new device minor for from input major namespace.
2695 * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2696 * parameters and whether ID can be allocated from dynamic range if there are
2697 * no free IDs in legacy range.
2698 */
2699int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2700 bool allow_dynamic)
2701{
2702 /*
2703 * This function should be called from input handler's ->connect()
2704 * methods, which are serialized with input_mutex, so no additional
2705 * locking is needed here.
2706 */
2707 if (legacy_base >= 0) {
2708 int minor = ida_alloc_range(&input_ida, legacy_base,
2709 legacy_base + legacy_num - 1,
2710 GFP_KERNEL);
2711 if (minor >= 0 || !allow_dynamic)
2712 return minor;
2713 }
2714
2715 return ida_alloc_range(&input_ida, INPUT_FIRST_DYNAMIC_DEV,
2716 INPUT_MAX_CHAR_DEVICES - 1, GFP_KERNEL);
2717}
2718EXPORT_SYMBOL(input_get_new_minor);
2719
2720/**
2721 * input_free_minor - release previously allocated minor
2722 * @minor: minor to be released
2723 *
2724 * This function releases previously allocated input minor so that it can be
2725 * reused later.
2726 */
2727void input_free_minor(unsigned int minor)
2728{
2729 ida_free(&input_ida, minor);
2730}
2731EXPORT_SYMBOL(input_free_minor);
2732
2733static int __init input_init(void)
2734{
2735 int err;
2736
2737 err = class_register(&input_class);
2738 if (err) {
2739 pr_err("unable to register input_dev class\n");
2740 return err;
2741 }
2742
2743 err = input_proc_init();
2744 if (err)
2745 goto fail1;
2746
2747 err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2748 INPUT_MAX_CHAR_DEVICES, "input");
2749 if (err) {
2750 pr_err("unable to register char major %d", INPUT_MAJOR);
2751 goto fail2;
2752 }
2753
2754 return 0;
2755
2756 fail2: input_proc_exit();
2757 fail1: class_unregister(&input_class);
2758 return err;
2759}
2760
2761static void __exit input_exit(void)
2762{
2763 input_proc_exit();
2764 unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2765 INPUT_MAX_CHAR_DEVICES);
2766 class_unregister(&input_class);
2767}
2768
2769subsys_initcall(input_init);
2770module_exit(input_exit);