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(timer: &dev->timer,
94 expires: jiffies + msecs_to_jiffies(m: dev->rep[REP_DELAY]));
95 }
96}
97
98static void input_stop_autorepeat(struct input_dev *dev)
99{
100 timer_delete(timer: &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, code: 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(axis: 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(value: *pval, old_val: *pold,
192 fuzz: 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, bm: 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, bm: 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, bm: dev->absbit, ABS_MAX))
263 disposition = input_handle_abs_event(dev, code, pval: &value);
264
265 break;
266
267 case EV_REL:
268 if (is_event_supported(code, bm: 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, bm: dev->mscbit, MSC_MAX))
275 disposition = INPUT_PASS_TO_ALL;
276
277 break;
278
279 case EV_LED:
280 if (is_event_supported(code, bm: 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, bm: 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, vals: dev->vals, count: 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(secs: 0, nsecs: 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, vals: dev->vals, count: 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, pval: &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(code: type, bm: dev->evbit, EV_MAX)) {
395 guard(spinlock_irqsave)(l: &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(code: type, bm: dev->evbit, EV_MAX)) {
419 guard(spinlock_irqsave)(l: &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 = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
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(dev: dst, EV_ABS, code: 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)(T: &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(poller: 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)(T: &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(poller: 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, bm: dev->evbit, EV_MAX)) {
682 for_each_set_bit(code, dev->key, KEY_CNT) {
683 input_handle_event(dev, EV_KEY, code, value: 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)(l: &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, value: 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(to: ke->scancode, from: &index, len: sizeof(index));
799
800 return 0;
801}
802
803static int input_default_setkeycode(struct input_dev *dev,
804 const struct input_keymap_entry *ke,
805 unsigned int *old_keycode)
806{
807 unsigned int index;
808 int error;
809 int i;
810
811 if (!dev->keycodesize)
812 return -EINVAL;
813
814 if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
815 index = ke->index;
816 } else {
817 error = input_scancode_to_scalar(ke, &index);
818 if (error)
819 return error;
820 }
821
822 if (index >= dev->keycodemax)
823 return -EINVAL;
824
825 if (dev->keycodesize < sizeof(ke->keycode) &&
826 (ke->keycode >> (dev->keycodesize * 8)))
827 return -EINVAL;
828
829 switch (dev->keycodesize) {
830 case 1: {
831 u8 *k = (u8 *)dev->keycode;
832 *old_keycode = k[index];
833 k[index] = ke->keycode;
834 break;
835 }
836 case 2: {
837 u16 *k = (u16 *)dev->keycode;
838 *old_keycode = k[index];
839 k[index] = ke->keycode;
840 break;
841 }
842 default: {
843 u32 *k = (u32 *)dev->keycode;
844 *old_keycode = k[index];
845 k[index] = ke->keycode;
846 break;
847 }
848 }
849
850 if (*old_keycode <= KEY_MAX) {
851 __clear_bit(*old_keycode, dev->keybit);
852 for (i = 0; i < dev->keycodemax; i++) {
853 if (input_fetch_keycode(dev, index: i) == *old_keycode) {
854 __set_bit(*old_keycode, dev->keybit);
855 /* Setting the bit twice is useless, so break */
856 break;
857 }
858 }
859 }
860
861 __set_bit(ke->keycode, dev->keybit);
862 return 0;
863}
864
865/**
866 * input_get_keycode - retrieve keycode currently mapped to a given scancode
867 * @dev: input device which keymap is being queried
868 * @ke: keymap entry
869 *
870 * This function should be called by anyone interested in retrieving current
871 * keymap. Presently evdev handlers use it.
872 */
873int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
874{
875 guard(spinlock_irqsave)(l: &dev->event_lock);
876
877 return dev->getkeycode(dev, ke);
878}
879EXPORT_SYMBOL(input_get_keycode);
880
881/**
882 * input_set_keycode - attribute a keycode to a given scancode
883 * @dev: input device which keymap is being updated
884 * @ke: new keymap entry
885 *
886 * This function should be called by anyone needing to update current
887 * keymap. Presently keyboard and evdev handlers use it.
888 */
889int input_set_keycode(struct input_dev *dev,
890 const struct input_keymap_entry *ke)
891{
892 unsigned int old_keycode;
893 int error;
894
895 if (ke->keycode > KEY_MAX)
896 return -EINVAL;
897
898 guard(spinlock_irqsave)(l: &dev->event_lock);
899
900 error = dev->setkeycode(dev, ke, &old_keycode);
901 if (error)
902 return error;
903
904 /* Make sure KEY_RESERVED did not get enabled. */
905 __clear_bit(KEY_RESERVED, dev->keybit);
906
907 /*
908 * Simulate keyup event if keycode is not present
909 * in the keymap anymore
910 */
911 if (old_keycode > KEY_MAX) {
912 dev_warn(dev->dev.parent ?: &dev->dev,
913 "%s: got too big old keycode %#x\n",
914 __func__, old_keycode);
915 } else if (test_bit(EV_KEY, dev->evbit) &&
916 !is_event_supported(code: old_keycode, bm: dev->keybit, KEY_MAX) &&
917 __test_and_clear_bit(old_keycode, dev->key)) {
918 /*
919 * We have to use input_event_dispose() here directly instead
920 * of input_handle_event() because the key we want to release
921 * here is considered no longer supported by the device and
922 * input_handle_event() will ignore it.
923 */
924 input_event_dispose(dev, INPUT_PASS_TO_HANDLERS,
925 EV_KEY, code: old_keycode, value: 0);
926 input_event_dispose(dev, INPUT_PASS_TO_HANDLERS | INPUT_FLUSH,
927 EV_SYN, SYN_REPORT, value: 1);
928 }
929
930 return 0;
931}
932EXPORT_SYMBOL(input_set_keycode);
933
934bool input_match_device_id(const struct input_dev *dev,
935 const struct input_device_id *id)
936{
937 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
938 if (id->bustype != dev->id.bustype)
939 return false;
940
941 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
942 if (id->vendor != dev->id.vendor)
943 return false;
944
945 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
946 if (id->product != dev->id.product)
947 return false;
948
949 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
950 if (id->version != dev->id.version)
951 return false;
952
953 if (!bitmap_subset(src1: id->evbit, src2: dev->evbit, EV_MAX) ||
954 !bitmap_subset(src1: id->keybit, src2: dev->keybit, KEY_MAX) ||
955 !bitmap_subset(src1: id->relbit, src2: dev->relbit, REL_MAX) ||
956 !bitmap_subset(src1: id->absbit, src2: dev->absbit, ABS_MAX) ||
957 !bitmap_subset(src1: id->mscbit, src2: dev->mscbit, MSC_MAX) ||
958 !bitmap_subset(src1: id->ledbit, src2: dev->ledbit, LED_MAX) ||
959 !bitmap_subset(src1: id->sndbit, src2: dev->sndbit, SND_MAX) ||
960 !bitmap_subset(src1: id->ffbit, src2: dev->ffbit, FF_MAX) ||
961 !bitmap_subset(src1: id->swbit, src2: dev->swbit, SW_MAX) ||
962 !bitmap_subset(src1: id->propbit, src2: dev->propbit, INPUT_PROP_MAX)) {
963 return false;
964 }
965
966 return true;
967}
968EXPORT_SYMBOL(input_match_device_id);
969
970static const struct input_device_id *input_match_device(struct input_handler *handler,
971 struct input_dev *dev)
972{
973 const struct input_device_id *id;
974
975 for (id = handler->id_table; id->flags; id++) {
976 if (input_match_device_id(dev, id) &&
977 (!handler->match || handler->match(handler, dev))) {
978 return id;
979 }
980 }
981
982 return NULL;
983}
984
985static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
986{
987 const struct input_device_id *id;
988 int error;
989
990 id = input_match_device(handler, dev);
991 if (!id)
992 return -ENODEV;
993
994 error = handler->connect(handler, dev, id);
995 if (error && error != -ENODEV)
996 pr_err("failed to attach handler %s to device %s, error: %d\n",
997 handler->name, kobject_name(&dev->dev.kobj), error);
998
999 return error;
1000}
1001
1002#ifdef CONFIG_PROC_FS
1003
1004static struct proc_dir_entry *proc_bus_input_dir;
1005static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1006static int input_devices_state;
1007
1008static inline void input_wakeup_procfs_readers(void)
1009{
1010 input_devices_state++;
1011 wake_up(&input_devices_poll_wait);
1012}
1013
1014struct input_seq_state {
1015 unsigned short pos;
1016 bool mutex_acquired;
1017 int input_devices_state;
1018};
1019
1020static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1021{
1022 struct seq_file *seq = file->private_data;
1023 struct input_seq_state *state = seq->private;
1024
1025 poll_wait(filp: file, wait_address: &input_devices_poll_wait, p: wait);
1026 if (state->input_devices_state != input_devices_state) {
1027 state->input_devices_state = input_devices_state;
1028 return EPOLLIN | EPOLLRDNORM;
1029 }
1030
1031 return 0;
1032}
1033
1034static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1035{
1036 struct input_seq_state *state = seq->private;
1037 int error;
1038
1039 error = mutex_lock_interruptible(lock: &input_mutex);
1040 if (error) {
1041 state->mutex_acquired = false;
1042 return ERR_PTR(error);
1043 }
1044
1045 state->mutex_acquired = true;
1046
1047 return seq_list_start(head: &input_dev_list, pos: *pos);
1048}
1049
1050static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1051{
1052 return seq_list_next(v, head: &input_dev_list, ppos: pos);
1053}
1054
1055static void input_seq_stop(struct seq_file *seq, void *v)
1056{
1057 struct input_seq_state *state = seq->private;
1058
1059 if (state->mutex_acquired)
1060 mutex_unlock(lock: &input_mutex);
1061}
1062
1063static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1064 unsigned long *bitmap, int max)
1065{
1066 int i;
1067 bool skip_empty = true;
1068 char buf[18];
1069
1070 seq_printf(m: seq, fmt: "B: %s=", name);
1071
1072 for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1073 if (input_bits_to_string(buf, buf_size: sizeof(buf),
1074 bits: bitmap[i], skip_empty)) {
1075 skip_empty = false;
1076 seq_printf(m: seq, fmt: "%s%s", buf, i > 0 ? " " : "");
1077 }
1078 }
1079
1080 /*
1081 * If no output was produced print a single 0.
1082 */
1083 if (skip_empty)
1084 seq_putc(m: seq, c: '0');
1085
1086 seq_putc(m: seq, c: '\n');
1087}
1088
1089static int input_devices_seq_show(struct seq_file *seq, void *v)
1090{
1091 struct input_dev *dev = container_of(v, struct input_dev, node);
1092 const char *path = kobject_get_path(kobj: &dev->dev.kobj, GFP_KERNEL);
1093 struct input_handle *handle;
1094
1095 seq_printf(m: seq, fmt: "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1096 dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1097
1098 seq_printf(m: seq, fmt: "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1099 seq_printf(m: seq, fmt: "P: Phys=%s\n", dev->phys ? dev->phys : "");
1100 seq_printf(m: seq, fmt: "S: Sysfs=%s\n", path ? path : "");
1101 seq_printf(m: seq, fmt: "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1102 seq_puts(m: seq, s: "H: Handlers=");
1103
1104 list_for_each_entry(handle, &dev->h_list, d_node)
1105 seq_printf(m: seq, fmt: "%s ", handle->name);
1106 seq_putc(m: seq, c: '\n');
1107
1108 input_seq_print_bitmap(seq, name: "PROP", bitmap: dev->propbit, INPUT_PROP_MAX);
1109
1110 input_seq_print_bitmap(seq, name: "EV", bitmap: dev->evbit, EV_MAX);
1111 if (test_bit(EV_KEY, dev->evbit))
1112 input_seq_print_bitmap(seq, name: "KEY", bitmap: dev->keybit, KEY_MAX);
1113 if (test_bit(EV_REL, dev->evbit))
1114 input_seq_print_bitmap(seq, name: "REL", bitmap: dev->relbit, REL_MAX);
1115 if (test_bit(EV_ABS, dev->evbit))
1116 input_seq_print_bitmap(seq, name: "ABS", bitmap: dev->absbit, ABS_MAX);
1117 if (test_bit(EV_MSC, dev->evbit))
1118 input_seq_print_bitmap(seq, name: "MSC", bitmap: dev->mscbit, MSC_MAX);
1119 if (test_bit(EV_LED, dev->evbit))
1120 input_seq_print_bitmap(seq, name: "LED", bitmap: dev->ledbit, LED_MAX);
1121 if (test_bit(EV_SND, dev->evbit))
1122 input_seq_print_bitmap(seq, name: "SND", bitmap: dev->sndbit, SND_MAX);
1123 if (test_bit(EV_FF, dev->evbit))
1124 input_seq_print_bitmap(seq, name: "FF", bitmap: dev->ffbit, FF_MAX);
1125 if (test_bit(EV_SW, dev->evbit))
1126 input_seq_print_bitmap(seq, name: "SW", bitmap: dev->swbit, SW_MAX);
1127
1128 seq_putc(m: seq, c: '\n');
1129
1130 kfree(objp: path);
1131 return 0;
1132}
1133
1134static const struct seq_operations input_devices_seq_ops = {
1135 .start = input_devices_seq_start,
1136 .next = input_devices_seq_next,
1137 .stop = input_seq_stop,
1138 .show = input_devices_seq_show,
1139};
1140
1141static int input_proc_devices_open(struct inode *inode, struct file *file)
1142{
1143 return seq_open_private(file, &input_devices_seq_ops,
1144 sizeof(struct input_seq_state));
1145}
1146
1147static const struct proc_ops input_devices_proc_ops = {
1148 .proc_open = input_proc_devices_open,
1149 .proc_poll = input_proc_devices_poll,
1150 .proc_read = seq_read,
1151 .proc_lseek = seq_lseek,
1152 .proc_release = seq_release_private,
1153};
1154
1155static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1156{
1157 struct input_seq_state *state = seq->private;
1158 int error;
1159
1160 error = mutex_lock_interruptible(lock: &input_mutex);
1161 if (error) {
1162 state->mutex_acquired = false;
1163 return ERR_PTR(error);
1164 }
1165
1166 state->mutex_acquired = true;
1167 state->pos = *pos;
1168
1169 return seq_list_start(head: &input_handler_list, pos: *pos);
1170}
1171
1172static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1173{
1174 struct input_seq_state *state = seq->private;
1175
1176 state->pos = *pos + 1;
1177 return seq_list_next(v, head: &input_handler_list, ppos: pos);
1178}
1179
1180static int input_handlers_seq_show(struct seq_file *seq, void *v)
1181{
1182 struct input_handler *handler = container_of(v, struct input_handler, node);
1183 struct input_seq_state *state = seq->private;
1184
1185 seq_printf(m: seq, fmt: "N: Number=%u Name=%s", state->pos, handler->name);
1186 if (handler->filter)
1187 seq_puts(m: seq, s: " (filter)");
1188 if (handler->legacy_minors)
1189 seq_printf(m: seq, fmt: " Minor=%d", handler->minor);
1190 seq_putc(m: seq, c: '\n');
1191
1192 return 0;
1193}
1194
1195static const struct seq_operations input_handlers_seq_ops = {
1196 .start = input_handlers_seq_start,
1197 .next = input_handlers_seq_next,
1198 .stop = input_seq_stop,
1199 .show = input_handlers_seq_show,
1200};
1201
1202static int input_proc_handlers_open(struct inode *inode, struct file *file)
1203{
1204 return seq_open_private(file, &input_handlers_seq_ops,
1205 sizeof(struct input_seq_state));
1206}
1207
1208static const struct proc_ops input_handlers_proc_ops = {
1209 .proc_open = input_proc_handlers_open,
1210 .proc_read = seq_read,
1211 .proc_lseek = seq_lseek,
1212 .proc_release = seq_release_private,
1213};
1214
1215static int __init input_proc_init(void)
1216{
1217 struct proc_dir_entry *entry;
1218
1219 proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1220 if (!proc_bus_input_dir)
1221 return -ENOMEM;
1222
1223 entry = proc_create(name: "devices", mode: 0, parent: proc_bus_input_dir,
1224 proc_ops: &input_devices_proc_ops);
1225 if (!entry)
1226 goto fail1;
1227
1228 entry = proc_create(name: "handlers", mode: 0, parent: proc_bus_input_dir,
1229 proc_ops: &input_handlers_proc_ops);
1230 if (!entry)
1231 goto fail2;
1232
1233 return 0;
1234
1235 fail2: remove_proc_entry("devices", proc_bus_input_dir);
1236 fail1: remove_proc_entry("bus/input", NULL);
1237 return -ENOMEM;
1238}
1239
1240static void input_proc_exit(void)
1241{
1242 remove_proc_entry("devices", proc_bus_input_dir);
1243 remove_proc_entry("handlers", proc_bus_input_dir);
1244 remove_proc_entry("bus/input", NULL);
1245}
1246
1247#else /* !CONFIG_PROC_FS */
1248static inline void input_wakeup_procfs_readers(void) { }
1249static inline int input_proc_init(void) { return 0; }
1250static inline void input_proc_exit(void) { }
1251#endif
1252
1253#define INPUT_DEV_STRING_ATTR_SHOW(name) \
1254static ssize_t input_dev_show_##name(struct device *dev, \
1255 struct device_attribute *attr, \
1256 char *buf) \
1257{ \
1258 struct input_dev *input_dev = to_input_dev(dev); \
1259 \
1260 return sysfs_emit(buf, "%s\n", \
1261 input_dev->name ? input_dev->name : ""); \
1262} \
1263static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1264
1265INPUT_DEV_STRING_ATTR_SHOW(name);
1266INPUT_DEV_STRING_ATTR_SHOW(phys);
1267INPUT_DEV_STRING_ATTR_SHOW(uniq);
1268
1269static int input_print_modalias_bits(char *buf, int size,
1270 char name, const unsigned long *bm,
1271 unsigned int min_bit, unsigned int max_bit)
1272{
1273 int bit = min_bit;
1274 int len = 0;
1275
1276 len += snprintf(buf, max(size, 0), fmt: "%c", name);
1277 for_each_set_bit_from(bit, bm, max_bit)
1278 len += snprintf(buf: buf + len, max(size - len, 0), fmt: "%X,", bit);
1279 return len;
1280}
1281
1282static int input_print_modalias_parts(char *buf, int size, int full_len,
1283 const struct input_dev *id)
1284{
1285 int len, klen, remainder, space;
1286
1287 len = snprintf(buf, max(size, 0),
1288 fmt: "input:b%04Xv%04Xp%04Xe%04X-",
1289 id->id.bustype, id->id.vendor,
1290 id->id.product, id->id.version);
1291
1292 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1293 name: 'e', bm: id->evbit, min_bit: 0, EV_MAX);
1294
1295 /*
1296 * Calculate the remaining space in the buffer making sure we
1297 * have place for the terminating 0.
1298 */
1299 space = max(size - (len + 1), 0);
1300
1301 klen = input_print_modalias_bits(buf: buf + len, size: size - len,
1302 name: 'k', bm: id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1303 len += klen;
1304
1305 /*
1306 * If we have more data than we can fit in the buffer, check
1307 * if we can trim key data to fit in the rest. We will indicate
1308 * that key data is incomplete by adding "+" sign at the end, like
1309 * this: * "k1,2,3,45,+,".
1310 *
1311 * Note that we shortest key info (if present) is "k+," so we
1312 * can only try to trim if key data is longer than that.
1313 */
1314 if (full_len && size < full_len + 1 && klen > 3) {
1315 remainder = full_len - len;
1316 /*
1317 * We can only trim if we have space for the remainder
1318 * and also for at least "k+," which is 3 more characters.
1319 */
1320 if (remainder <= space - 3) {
1321 /*
1322 * We are guaranteed to have 'k' in the buffer, so
1323 * we need at least 3 additional bytes for storing
1324 * "+," in addition to the remainder.
1325 */
1326 for (int i = size - 1 - remainder - 3; i >= 0; i--) {
1327 if (buf[i] == 'k' || buf[i] == ',') {
1328 strcpy(buf + i + 1, "+,");
1329 len = i + 3; /* Not counting '\0' */
1330 break;
1331 }
1332 }
1333 }
1334 }
1335
1336 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1337 name: 'r', bm: id->relbit, min_bit: 0, REL_MAX);
1338 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1339 name: 'a', bm: id->absbit, min_bit: 0, ABS_MAX);
1340 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1341 name: 'm', bm: id->mscbit, min_bit: 0, MSC_MAX);
1342 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1343 name: 'l', bm: id->ledbit, min_bit: 0, LED_MAX);
1344 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1345 name: 's', bm: id->sndbit, min_bit: 0, SND_MAX);
1346 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1347 name: 'f', bm: id->ffbit, min_bit: 0, FF_MAX);
1348 len += input_print_modalias_bits(buf: buf + len, size: size - len,
1349 name: 'w', bm: id->swbit, min_bit: 0, SW_MAX);
1350
1351 return len;
1352}
1353
1354static int input_print_modalias(char *buf, int size, const struct input_dev *id)
1355{
1356 int full_len;
1357
1358 /*
1359 * Printing is done in 2 passes: first one figures out total length
1360 * needed for the modalias string, second one will try to trim key
1361 * data in case when buffer is too small for the entire modalias.
1362 * If the buffer is too small regardless, it will fill as much as it
1363 * can (without trimming key data) into the buffer and leave it to
1364 * the caller to figure out what to do with the result.
1365 */
1366 full_len = input_print_modalias_parts(NULL, size: 0, full_len: 0, id);
1367 return input_print_modalias_parts(buf, size, full_len, id);
1368}
1369
1370static ssize_t input_dev_show_modalias(struct device *dev,
1371 struct device_attribute *attr,
1372 char *buf)
1373{
1374 struct input_dev *id = to_input_dev(dev);
1375 ssize_t len;
1376
1377 len = input_print_modalias(buf, PAGE_SIZE, id);
1378 if (len < PAGE_SIZE - 2)
1379 len += snprintf(buf: buf + len, PAGE_SIZE - len, fmt: "\n");
1380
1381 return min_t(int, len, PAGE_SIZE);
1382}
1383static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1384
1385static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1386 int max, int add_cr);
1387
1388static ssize_t input_dev_show_properties(struct device *dev,
1389 struct device_attribute *attr,
1390 char *buf)
1391{
1392 struct input_dev *input_dev = to_input_dev(dev);
1393 int len = input_print_bitmap(buf, PAGE_SIZE, bitmap: input_dev->propbit,
1394 INPUT_PROP_MAX, add_cr: true);
1395 return min_t(int, len, PAGE_SIZE);
1396}
1397static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1398
1399static int input_inhibit_device(struct input_dev *dev);
1400static int input_uninhibit_device(struct input_dev *dev);
1401
1402static ssize_t inhibited_show(struct device *dev,
1403 struct device_attribute *attr,
1404 char *buf)
1405{
1406 struct input_dev *input_dev = to_input_dev(dev);
1407
1408 return sysfs_emit(buf, fmt: "%d\n", input_dev->inhibited);
1409}
1410
1411static ssize_t inhibited_store(struct device *dev,
1412 struct device_attribute *attr, const char *buf,
1413 size_t len)
1414{
1415 struct input_dev *input_dev = to_input_dev(dev);
1416 ssize_t rv;
1417 bool inhibited;
1418
1419 if (kstrtobool(s: buf, res: &inhibited))
1420 return -EINVAL;
1421
1422 if (inhibited)
1423 rv = input_inhibit_device(dev: input_dev);
1424 else
1425 rv = input_uninhibit_device(dev: input_dev);
1426
1427 if (rv != 0)
1428 return rv;
1429
1430 return len;
1431}
1432
1433static DEVICE_ATTR_RW(inhibited);
1434
1435static struct attribute *input_dev_attrs[] = {
1436 &dev_attr_name.attr,
1437 &dev_attr_phys.attr,
1438 &dev_attr_uniq.attr,
1439 &dev_attr_modalias.attr,
1440 &dev_attr_properties.attr,
1441 &dev_attr_inhibited.attr,
1442 NULL
1443};
1444
1445static const struct attribute_group input_dev_attr_group = {
1446 .attrs = input_dev_attrs,
1447};
1448
1449#define INPUT_DEV_ID_ATTR(name) \
1450static ssize_t input_dev_show_id_##name(struct device *dev, \
1451 struct device_attribute *attr, \
1452 char *buf) \
1453{ \
1454 struct input_dev *input_dev = to_input_dev(dev); \
1455 return sysfs_emit(buf, "%04x\n", input_dev->id.name); \
1456} \
1457static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1458
1459INPUT_DEV_ID_ATTR(bustype);
1460INPUT_DEV_ID_ATTR(vendor);
1461INPUT_DEV_ID_ATTR(product);
1462INPUT_DEV_ID_ATTR(version);
1463
1464static struct attribute *input_dev_id_attrs[] = {
1465 &dev_attr_bustype.attr,
1466 &dev_attr_vendor.attr,
1467 &dev_attr_product.attr,
1468 &dev_attr_version.attr,
1469 NULL
1470};
1471
1472static const struct attribute_group input_dev_id_attr_group = {
1473 .name = "id",
1474 .attrs = input_dev_id_attrs,
1475};
1476
1477static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1478 int max, int add_cr)
1479{
1480 int i;
1481 int len = 0;
1482 bool skip_empty = true;
1483
1484 for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1485 len += input_bits_to_string(buf: buf + len, max(buf_size - len, 0),
1486 bits: bitmap[i], skip_empty);
1487 if (len) {
1488 skip_empty = false;
1489 if (i > 0)
1490 len += snprintf(buf: buf + len, max(buf_size - len, 0), fmt: " ");
1491 }
1492 }
1493
1494 /*
1495 * If no output was produced print a single 0.
1496 */
1497 if (len == 0)
1498 len = snprintf(buf, size: buf_size, fmt: "%d", 0);
1499
1500 if (add_cr)
1501 len += snprintf(buf: buf + len, max(buf_size - len, 0), fmt: "\n");
1502
1503 return len;
1504}
1505
1506#define INPUT_DEV_CAP_ATTR(ev, bm) \
1507static ssize_t input_dev_show_cap_##bm(struct device *dev, \
1508 struct device_attribute *attr, \
1509 char *buf) \
1510{ \
1511 struct input_dev *input_dev = to_input_dev(dev); \
1512 int len = input_print_bitmap(buf, PAGE_SIZE, \
1513 input_dev->bm##bit, ev##_MAX, \
1514 true); \
1515 return min_t(int, len, PAGE_SIZE); \
1516} \
1517static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1518
1519INPUT_DEV_CAP_ATTR(EV, ev);
1520INPUT_DEV_CAP_ATTR(KEY, key);
1521INPUT_DEV_CAP_ATTR(REL, rel);
1522INPUT_DEV_CAP_ATTR(ABS, abs);
1523INPUT_DEV_CAP_ATTR(MSC, msc);
1524INPUT_DEV_CAP_ATTR(LED, led);
1525INPUT_DEV_CAP_ATTR(SND, snd);
1526INPUT_DEV_CAP_ATTR(FF, ff);
1527INPUT_DEV_CAP_ATTR(SW, sw);
1528
1529static struct attribute *input_dev_caps_attrs[] = {
1530 &dev_attr_ev.attr,
1531 &dev_attr_key.attr,
1532 &dev_attr_rel.attr,
1533 &dev_attr_abs.attr,
1534 &dev_attr_msc.attr,
1535 &dev_attr_led.attr,
1536 &dev_attr_snd.attr,
1537 &dev_attr_ff.attr,
1538 &dev_attr_sw.attr,
1539 NULL
1540};
1541
1542static const struct attribute_group input_dev_caps_attr_group = {
1543 .name = "capabilities",
1544 .attrs = input_dev_caps_attrs,
1545};
1546
1547static const struct attribute_group *input_dev_attr_groups[] = {
1548 &input_dev_attr_group,
1549 &input_dev_id_attr_group,
1550 &input_dev_caps_attr_group,
1551 &input_poller_attribute_group,
1552 NULL
1553};
1554
1555static void input_dev_release(struct device *device)
1556{
1557 struct input_dev *dev = to_input_dev(device);
1558
1559 input_ff_destroy(dev);
1560 input_mt_destroy_slots(dev);
1561 kfree(objp: dev->poller);
1562 kfree(objp: dev->absinfo);
1563 kfree(objp: dev->vals);
1564 kfree(objp: dev);
1565
1566 module_put(THIS_MODULE);
1567}
1568
1569/*
1570 * Input uevent interface - loading event handlers based on
1571 * device bitfields.
1572 */
1573static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1574 const char *name, const unsigned long *bitmap, int max)
1575{
1576 int len;
1577
1578 if (add_uevent_var(env, format: "%s", name))
1579 return -ENOMEM;
1580
1581 len = input_print_bitmap(buf: &env->buf[env->buflen - 1],
1582 buf_size: sizeof(env->buf) - env->buflen,
1583 bitmap, max, add_cr: false);
1584 if (len >= (sizeof(env->buf) - env->buflen))
1585 return -ENOMEM;
1586
1587 env->buflen += len;
1588 return 0;
1589}
1590
1591/*
1592 * This is a pretty gross hack. When building uevent data the driver core
1593 * may try adding more environment variables to kobj_uevent_env without
1594 * telling us, so we have no idea how much of the buffer we can use to
1595 * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially
1596 * reduce amount of memory we will use for the modalias environment variable.
1597 *
1598 * The potential additions are:
1599 *
1600 * SEQNUM=18446744073709551615 - (%llu - 28 bytes)
1601 * HOME=/ (6 bytes)
1602 * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes)
1603 *
1604 * 68 bytes total. Allow extra buffer - 96 bytes
1605 */
1606#define UEVENT_ENV_EXTRA_LEN 96
1607
1608static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1609 const struct input_dev *dev)
1610{
1611 int len;
1612
1613 if (add_uevent_var(env, format: "MODALIAS="))
1614 return -ENOMEM;
1615
1616 len = input_print_modalias(buf: &env->buf[env->buflen - 1],
1617 size: (int)sizeof(env->buf) - env->buflen -
1618 UEVENT_ENV_EXTRA_LEN,
1619 id: dev);
1620 if (len >= ((int)sizeof(env->buf) - env->buflen -
1621 UEVENT_ENV_EXTRA_LEN))
1622 return -ENOMEM;
1623
1624 env->buflen += len;
1625 return 0;
1626}
1627
1628#define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \
1629 do { \
1630 int err = add_uevent_var(env, fmt, val); \
1631 if (err) \
1632 return err; \
1633 } while (0)
1634
1635#define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \
1636 do { \
1637 int err = input_add_uevent_bm_var(env, name, bm, max); \
1638 if (err) \
1639 return err; \
1640 } while (0)
1641
1642#define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \
1643 do { \
1644 int err = input_add_uevent_modalias_var(env, dev); \
1645 if (err) \
1646 return err; \
1647 } while (0)
1648
1649static int input_dev_uevent(const struct device *device, struct kobj_uevent_env *env)
1650{
1651 const struct input_dev *dev = to_input_dev(device);
1652
1653 INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1654 dev->id.bustype, dev->id.vendor,
1655 dev->id.product, dev->id.version);
1656 if (dev->name)
1657 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1658 if (dev->phys)
1659 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1660 if (dev->uniq)
1661 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1662
1663 INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1664
1665 INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1666 if (test_bit(EV_KEY, dev->evbit))
1667 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1668 if (test_bit(EV_REL, dev->evbit))
1669 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1670 if (test_bit(EV_ABS, dev->evbit))
1671 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1672 if (test_bit(EV_MSC, dev->evbit))
1673 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1674 if (test_bit(EV_LED, dev->evbit))
1675 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1676 if (test_bit(EV_SND, dev->evbit))
1677 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1678 if (test_bit(EV_FF, dev->evbit))
1679 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1680 if (test_bit(EV_SW, dev->evbit))
1681 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1682
1683 INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1684
1685 return 0;
1686}
1687
1688#define INPUT_DO_TOGGLE(dev, type, bits, on) \
1689 do { \
1690 int i; \
1691 bool active; \
1692 \
1693 if (!test_bit(EV_##type, dev->evbit)) \
1694 break; \
1695 \
1696 for_each_set_bit(i, dev->bits##bit, type##_CNT) { \
1697 active = test_bit(i, dev->bits); \
1698 if (!active && !on) \
1699 continue; \
1700 \
1701 dev->event(dev, EV_##type, i, on ? active : 0); \
1702 } \
1703 } while (0)
1704
1705static void input_dev_toggle(struct input_dev *dev, bool activate)
1706{
1707 if (!dev->event)
1708 return;
1709
1710 INPUT_DO_TOGGLE(dev, LED, led, activate);
1711 INPUT_DO_TOGGLE(dev, SND, snd, activate);
1712
1713 if (activate && test_bit(EV_REP, dev->evbit)) {
1714 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1715 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1716 }
1717}
1718
1719/**
1720 * input_reset_device() - reset/restore the state of input device
1721 * @dev: input device whose state needs to be reset
1722 *
1723 * This function tries to reset the state of an opened input device and
1724 * bring internal state and state if the hardware in sync with each other.
1725 * We mark all keys as released, restore LED state, repeat rate, etc.
1726 */
1727void input_reset_device(struct input_dev *dev)
1728{
1729 guard(mutex)(T: &dev->mutex);
1730 guard(spinlock_irqsave)(l: &dev->event_lock);
1731
1732 input_dev_toggle(dev, activate: true);
1733 if (input_dev_release_keys(dev))
1734 input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
1735}
1736EXPORT_SYMBOL(input_reset_device);
1737
1738static int input_inhibit_device(struct input_dev *dev)
1739{
1740 guard(mutex)(T: &dev->mutex);
1741
1742 if (dev->inhibited)
1743 return 0;
1744
1745 if (dev->users) {
1746 if (dev->close)
1747 dev->close(dev);
1748 if (dev->poller)
1749 input_dev_poller_stop(poller: dev->poller);
1750 }
1751
1752 scoped_guard(spinlock_irq, &dev->event_lock) {
1753 input_mt_release_slots(dev);
1754 input_dev_release_keys(dev);
1755 input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
1756 input_dev_toggle(dev, activate: false);
1757 }
1758
1759 dev->inhibited = true;
1760
1761 return 0;
1762}
1763
1764static int input_uninhibit_device(struct input_dev *dev)
1765{
1766 int error;
1767
1768 guard(mutex)(T: &dev->mutex);
1769
1770 if (!dev->inhibited)
1771 return 0;
1772
1773 if (dev->users) {
1774 if (dev->open) {
1775 error = dev->open(dev);
1776 if (error)
1777 return error;
1778 }
1779 if (dev->poller)
1780 input_dev_poller_start(poller: dev->poller);
1781 }
1782
1783 dev->inhibited = false;
1784
1785 scoped_guard(spinlock_irq, &dev->event_lock)
1786 input_dev_toggle(dev, activate: true);
1787
1788 return 0;
1789}
1790
1791static int input_dev_suspend(struct device *dev)
1792{
1793 struct input_dev *input_dev = to_input_dev(dev);
1794
1795 guard(spinlock_irq)(l: &input_dev->event_lock);
1796
1797 /*
1798 * Keys that are pressed now are unlikely to be
1799 * still pressed when we resume.
1800 */
1801 if (input_dev_release_keys(dev: input_dev))
1802 input_handle_event(dev: input_dev, EV_SYN, SYN_REPORT, value: 1);
1803
1804 /* Turn off LEDs and sounds, if any are active. */
1805 input_dev_toggle(dev: input_dev, activate: false);
1806
1807 return 0;
1808}
1809
1810static int input_dev_resume(struct device *dev)
1811{
1812 struct input_dev *input_dev = to_input_dev(dev);
1813
1814 guard(spinlock_irq)(l: &input_dev->event_lock);
1815
1816 /* Restore state of LEDs and sounds, if any were active. */
1817 input_dev_toggle(dev: input_dev, activate: true);
1818
1819 return 0;
1820}
1821
1822static int input_dev_freeze(struct device *dev)
1823{
1824 struct input_dev *input_dev = to_input_dev(dev);
1825
1826 guard(spinlock_irq)(l: &input_dev->event_lock);
1827
1828 /*
1829 * Keys that are pressed now are unlikely to be
1830 * still pressed when we resume.
1831 */
1832 if (input_dev_release_keys(dev: input_dev))
1833 input_handle_event(dev: input_dev, EV_SYN, SYN_REPORT, value: 1);
1834
1835 return 0;
1836}
1837
1838static int input_dev_poweroff(struct device *dev)
1839{
1840 struct input_dev *input_dev = to_input_dev(dev);
1841
1842 guard(spinlock_irq)(l: &input_dev->event_lock);
1843
1844 /* Turn off LEDs and sounds, if any are active. */
1845 input_dev_toggle(dev: input_dev, activate: false);
1846
1847 return 0;
1848}
1849
1850static const struct dev_pm_ops input_dev_pm_ops = {
1851 .suspend = input_dev_suspend,
1852 .resume = input_dev_resume,
1853 .freeze = input_dev_freeze,
1854 .poweroff = input_dev_poweroff,
1855 .restore = input_dev_resume,
1856};
1857
1858static const struct device_type input_dev_type = {
1859 .groups = input_dev_attr_groups,
1860 .release = input_dev_release,
1861 .uevent = input_dev_uevent,
1862 .pm = pm_sleep_ptr(&input_dev_pm_ops),
1863};
1864
1865static char *input_devnode(const struct device *dev, umode_t *mode)
1866{
1867 return kasprintf(GFP_KERNEL, fmt: "input/%s", dev_name(dev));
1868}
1869
1870const struct class input_class = {
1871 .name = "input",
1872 .devnode = input_devnode,
1873};
1874EXPORT_SYMBOL_GPL(input_class);
1875
1876/**
1877 * input_allocate_device - allocate memory for new input device
1878 *
1879 * Returns prepared struct input_dev or %NULL.
1880 *
1881 * NOTE: Use input_free_device() to free devices that have not been
1882 * registered; input_unregister_device() should be used for already
1883 * registered devices.
1884 */
1885struct input_dev *input_allocate_device(void)
1886{
1887 static atomic_t input_no = ATOMIC_INIT(-1);
1888 struct input_dev *dev;
1889
1890 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1891 if (!dev)
1892 return NULL;
1893
1894 /*
1895 * Start with space for SYN_REPORT + 7 EV_KEY/EV_MSC events + 2 spare,
1896 * see input_estimate_events_per_packet(). We will tune the number
1897 * when we register the device.
1898 */
1899 dev->max_vals = 10;
1900 dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
1901 if (!dev->vals) {
1902 kfree(objp: dev);
1903 return NULL;
1904 }
1905
1906 mutex_init(&dev->mutex);
1907 spin_lock_init(&dev->event_lock);
1908 timer_setup(&dev->timer, NULL, 0);
1909 INIT_LIST_HEAD(list: &dev->h_list);
1910 INIT_LIST_HEAD(list: &dev->node);
1911
1912 dev->dev.type = &input_dev_type;
1913 dev->dev.class = &input_class;
1914 device_initialize(dev: &dev->dev);
1915 /*
1916 * From this point on we can no longer simply "kfree(dev)", we need
1917 * to use input_free_device() so that device core properly frees its
1918 * resources associated with the input device.
1919 */
1920
1921 dev_set_name(dev: &dev->dev, name: "input%lu",
1922 (unsigned long)atomic_inc_return(v: &input_no));
1923
1924 __module_get(THIS_MODULE);
1925
1926 return dev;
1927}
1928EXPORT_SYMBOL(input_allocate_device);
1929
1930struct input_devres {
1931 struct input_dev *input;
1932};
1933
1934static int devm_input_device_match(struct device *dev, void *res, void *data)
1935{
1936 struct input_devres *devres = res;
1937
1938 return devres->input == data;
1939}
1940
1941static void devm_input_device_release(struct device *dev, void *res)
1942{
1943 struct input_devres *devres = res;
1944 struct input_dev *input = devres->input;
1945
1946 dev_dbg(dev, "%s: dropping reference to %s\n",
1947 __func__, dev_name(&input->dev));
1948 input_put_device(dev: input);
1949}
1950
1951/**
1952 * devm_input_allocate_device - allocate managed input device
1953 * @dev: device owning the input device being created
1954 *
1955 * Returns prepared struct input_dev or %NULL.
1956 *
1957 * Managed input devices do not need to be explicitly unregistered or
1958 * freed as it will be done automatically when owner device unbinds from
1959 * its driver (or binding fails). Once managed input device is allocated,
1960 * it is ready to be set up and registered in the same fashion as regular
1961 * input device. There are no special devm_input_device_[un]register()
1962 * variants, regular ones work with both managed and unmanaged devices,
1963 * should you need them. In most cases however, managed input device need
1964 * not be explicitly unregistered or freed.
1965 *
1966 * NOTE: the owner device is set up as parent of input device and users
1967 * should not override it.
1968 */
1969struct input_dev *devm_input_allocate_device(struct device *dev)
1970{
1971 struct input_dev *input;
1972 struct input_devres *devres;
1973
1974 devres = devres_alloc(devm_input_device_release,
1975 sizeof(*devres), GFP_KERNEL);
1976 if (!devres)
1977 return NULL;
1978
1979 input = input_allocate_device();
1980 if (!input) {
1981 devres_free(res: devres);
1982 return NULL;
1983 }
1984
1985 input->dev.parent = dev;
1986 input->devres_managed = true;
1987
1988 devres->input = input;
1989 devres_add(dev, res: devres);
1990
1991 return input;
1992}
1993EXPORT_SYMBOL(devm_input_allocate_device);
1994
1995/**
1996 * input_free_device - free memory occupied by input_dev structure
1997 * @dev: input device to free
1998 *
1999 * This function should only be used if input_register_device()
2000 * was not called yet or if it failed. Once device was registered
2001 * use input_unregister_device() and memory will be freed once last
2002 * reference to the device is dropped.
2003 *
2004 * Device should be allocated by input_allocate_device().
2005 *
2006 * NOTE: If there are references to the input device then memory
2007 * will not be freed until last reference is dropped.
2008 */
2009void input_free_device(struct input_dev *dev)
2010{
2011 if (dev) {
2012 if (dev->devres_managed)
2013 WARN_ON(devres_destroy(dev->dev.parent,
2014 devm_input_device_release,
2015 devm_input_device_match,
2016 dev));
2017 input_put_device(dev);
2018 }
2019}
2020EXPORT_SYMBOL(input_free_device);
2021
2022/**
2023 * input_set_timestamp - set timestamp for input events
2024 * @dev: input device to set timestamp for
2025 * @timestamp: the time at which the event has occurred
2026 * in CLOCK_MONOTONIC
2027 *
2028 * This function is intended to provide to the input system a more
2029 * accurate time of when an event actually occurred. The driver should
2030 * call this function as soon as a timestamp is acquired ensuring
2031 * clock conversions in input_set_timestamp are done correctly.
2032 *
2033 * The system entering suspend state between timestamp acquisition and
2034 * calling input_set_timestamp can result in inaccurate conversions.
2035 */
2036void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
2037{
2038 dev->timestamp[INPUT_CLK_MONO] = timestamp;
2039 dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(mono: timestamp);
2040 dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(tmono: timestamp,
2041 offs: TK_OFFS_BOOT);
2042}
2043EXPORT_SYMBOL(input_set_timestamp);
2044
2045/**
2046 * input_get_timestamp - get timestamp for input events
2047 * @dev: input device to get timestamp from
2048 *
2049 * A valid timestamp is a timestamp of non-zero value.
2050 */
2051ktime_t *input_get_timestamp(struct input_dev *dev)
2052{
2053 const ktime_t invalid_timestamp = ktime_set(secs: 0, nsecs: 0);
2054
2055 if (!ktime_compare(cmp1: dev->timestamp[INPUT_CLK_MONO], cmp2: invalid_timestamp))
2056 input_set_timestamp(dev, ktime_get());
2057
2058 return dev->timestamp;
2059}
2060EXPORT_SYMBOL(input_get_timestamp);
2061
2062/**
2063 * input_set_capability - mark device as capable of a certain event
2064 * @dev: device that is capable of emitting or accepting event
2065 * @type: type of the event (EV_KEY, EV_REL, etc...)
2066 * @code: event code
2067 *
2068 * In addition to setting up corresponding bit in appropriate capability
2069 * bitmap the function also adjusts dev->evbit.
2070 */
2071void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
2072{
2073 if (type < EV_CNT && input_max_code[type] &&
2074 code > input_max_code[type]) {
2075 pr_err("%s: invalid code %u for type %u\n", __func__, code,
2076 type);
2077 dump_stack();
2078 return;
2079 }
2080
2081 switch (type) {
2082 case EV_KEY:
2083 __set_bit(code, dev->keybit);
2084 break;
2085
2086 case EV_REL:
2087 __set_bit(code, dev->relbit);
2088 break;
2089
2090 case EV_ABS:
2091 input_alloc_absinfo(dev);
2092 __set_bit(code, dev->absbit);
2093 break;
2094
2095 case EV_MSC:
2096 __set_bit(code, dev->mscbit);
2097 break;
2098
2099 case EV_SW:
2100 __set_bit(code, dev->swbit);
2101 break;
2102
2103 case EV_LED:
2104 __set_bit(code, dev->ledbit);
2105 break;
2106
2107 case EV_SND:
2108 __set_bit(code, dev->sndbit);
2109 break;
2110
2111 case EV_FF:
2112 __set_bit(code, dev->ffbit);
2113 break;
2114
2115 case EV_PWR:
2116 /* do nothing */
2117 break;
2118
2119 default:
2120 pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2121 dump_stack();
2122 return;
2123 }
2124
2125 __set_bit(type, dev->evbit);
2126}
2127EXPORT_SYMBOL(input_set_capability);
2128
2129static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2130{
2131 int mt_slots;
2132 int i;
2133 unsigned int events;
2134
2135 if (dev->mt) {
2136 mt_slots = dev->mt->num_slots;
2137 } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2138 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2139 dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1;
2140 mt_slots = clamp(mt_slots, 2, 32);
2141 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2142 mt_slots = 2;
2143 } else {
2144 mt_slots = 0;
2145 }
2146
2147 events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2148
2149 if (test_bit(EV_ABS, dev->evbit))
2150 for_each_set_bit(i, dev->absbit, ABS_CNT)
2151 events += input_is_mt_axis(axis: i) ? mt_slots : 1;
2152
2153 if (test_bit(EV_REL, dev->evbit))
2154 events += bitmap_weight(src: dev->relbit, REL_CNT);
2155
2156 /* Make room for KEY and MSC events */
2157 events += 7;
2158
2159 return events;
2160}
2161
2162#define INPUT_CLEANSE_BITMASK(dev, type, bits) \
2163 do { \
2164 if (!test_bit(EV_##type, dev->evbit)) \
2165 memset(dev->bits##bit, 0, \
2166 sizeof(dev->bits##bit)); \
2167 } while (0)
2168
2169static void input_cleanse_bitmasks(struct input_dev *dev)
2170{
2171 INPUT_CLEANSE_BITMASK(dev, KEY, key);
2172 INPUT_CLEANSE_BITMASK(dev, REL, rel);
2173 INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2174 INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2175 INPUT_CLEANSE_BITMASK(dev, LED, led);
2176 INPUT_CLEANSE_BITMASK(dev, SND, snd);
2177 INPUT_CLEANSE_BITMASK(dev, FF, ff);
2178 INPUT_CLEANSE_BITMASK(dev, SW, sw);
2179}
2180
2181static void __input_unregister_device(struct input_dev *dev)
2182{
2183 struct input_handle *handle, *next;
2184
2185 input_disconnect_device(dev);
2186
2187 scoped_guard(mutex, &input_mutex) {
2188 list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2189 handle->handler->disconnect(handle);
2190 WARN_ON(!list_empty(&dev->h_list));
2191
2192 timer_delete_sync(timer: &dev->timer);
2193 list_del_init(entry: &dev->node);
2194
2195 input_wakeup_procfs_readers();
2196 }
2197
2198 device_del(dev: &dev->dev);
2199}
2200
2201static void devm_input_device_unregister(struct device *dev, void *res)
2202{
2203 struct input_devres *devres = res;
2204 struct input_dev *input = devres->input;
2205
2206 dev_dbg(dev, "%s: unregistering device %s\n",
2207 __func__, dev_name(&input->dev));
2208 __input_unregister_device(dev: input);
2209}
2210
2211/*
2212 * Generate software autorepeat event. Note that we take
2213 * dev->event_lock here to avoid racing with input_event
2214 * which may cause keys get "stuck".
2215 */
2216static void input_repeat_key(struct timer_list *t)
2217{
2218 struct input_dev *dev = timer_container_of(dev, t, timer);
2219
2220 guard(spinlock_irqsave)(l: &dev->event_lock);
2221
2222 if (!dev->inhibited &&
2223 test_bit(dev->repeat_key, dev->key) &&
2224 is_event_supported(code: dev->repeat_key, bm: dev->keybit, KEY_MAX)) {
2225
2226 input_set_timestamp(dev, ktime_get());
2227 input_handle_event(dev, EV_KEY, code: dev->repeat_key, value: 2);
2228 input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
2229
2230 if (dev->rep[REP_PERIOD])
2231 mod_timer(timer: &dev->timer, expires: jiffies +
2232 msecs_to_jiffies(m: dev->rep[REP_PERIOD]));
2233 }
2234}
2235
2236/**
2237 * input_enable_softrepeat - enable software autorepeat
2238 * @dev: input device
2239 * @delay: repeat delay
2240 * @period: repeat period
2241 *
2242 * Enable software autorepeat on the input device.
2243 */
2244void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2245{
2246 dev->timer.function = input_repeat_key;
2247 dev->rep[REP_DELAY] = delay;
2248 dev->rep[REP_PERIOD] = period;
2249}
2250EXPORT_SYMBOL(input_enable_softrepeat);
2251
2252bool input_device_enabled(struct input_dev *dev)
2253{
2254 lockdep_assert_held(&dev->mutex);
2255
2256 return !dev->inhibited && dev->users > 0;
2257}
2258EXPORT_SYMBOL_GPL(input_device_enabled);
2259
2260static int input_device_tune_vals(struct input_dev *dev)
2261{
2262 struct input_value *vals;
2263 unsigned int packet_size;
2264 unsigned int max_vals;
2265
2266 packet_size = input_estimate_events_per_packet(dev);
2267 if (dev->hint_events_per_packet < packet_size)
2268 dev->hint_events_per_packet = packet_size;
2269
2270 max_vals = dev->hint_events_per_packet + 2;
2271 if (dev->max_vals >= max_vals)
2272 return 0;
2273
2274 vals = kcalloc(max_vals, sizeof(*vals), GFP_KERNEL);
2275 if (!vals)
2276 return -ENOMEM;
2277
2278 scoped_guard(spinlock_irq, &dev->event_lock) {
2279 dev->max_vals = max_vals;
2280 swap(dev->vals, vals);
2281 }
2282
2283 /* Because of swap() above, this frees the old vals memory */
2284 kfree(objp: vals);
2285
2286 return 0;
2287}
2288
2289/**
2290 * input_register_device - register device with input core
2291 * @dev: device to be registered
2292 *
2293 * This function registers device with input core. The device must be
2294 * allocated with input_allocate_device() and all it's capabilities
2295 * set up before registering.
2296 * If function fails the device must be freed with input_free_device().
2297 * Once device has been successfully registered it can be unregistered
2298 * with input_unregister_device(); input_free_device() should not be
2299 * called in this case.
2300 *
2301 * Note that this function is also used to register managed input devices
2302 * (ones allocated with devm_input_allocate_device()). Such managed input
2303 * devices need not be explicitly unregistered or freed, their tear down
2304 * is controlled by the devres infrastructure. It is also worth noting
2305 * that tear down of managed input devices is internally a 2-step process:
2306 * registered managed input device is first unregistered, but stays in
2307 * memory and can still handle input_event() calls (although events will
2308 * not be delivered anywhere). The freeing of managed input device will
2309 * happen later, when devres stack is unwound to the point where device
2310 * allocation was made.
2311 */
2312int input_register_device(struct input_dev *dev)
2313{
2314 struct input_devres *devres = NULL;
2315 struct input_handler *handler;
2316 const char *path;
2317 int error;
2318
2319 if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2320 dev_err(&dev->dev,
2321 "Absolute device without dev->absinfo, refusing to register\n");
2322 return -EINVAL;
2323 }
2324
2325 if (dev->devres_managed) {
2326 devres = devres_alloc(devm_input_device_unregister,
2327 sizeof(*devres), GFP_KERNEL);
2328 if (!devres)
2329 return -ENOMEM;
2330
2331 devres->input = dev;
2332 }
2333
2334 /* Every input device generates EV_SYN/SYN_REPORT events. */
2335 __set_bit(EV_SYN, dev->evbit);
2336
2337 /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2338 __clear_bit(KEY_RESERVED, dev->keybit);
2339
2340 /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2341 input_cleanse_bitmasks(dev);
2342
2343 error = input_device_tune_vals(dev);
2344 if (error)
2345 goto err_devres_free;
2346
2347 /*
2348 * If delay and period are pre-set by the driver, then autorepeating
2349 * is handled by the driver itself and we don't do it in input.c.
2350 */
2351 if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2352 input_enable_softrepeat(dev, 250, 33);
2353
2354 if (!dev->getkeycode)
2355 dev->getkeycode = input_default_getkeycode;
2356
2357 if (!dev->setkeycode)
2358 dev->setkeycode = input_default_setkeycode;
2359
2360 if (dev->poller)
2361 input_dev_poller_finalize(poller: dev->poller);
2362
2363 error = device_add(dev: &dev->dev);
2364 if (error)
2365 goto err_devres_free;
2366
2367 path = kobject_get_path(kobj: &dev->dev.kobj, GFP_KERNEL);
2368 pr_info("%s as %s\n",
2369 dev->name ? dev->name : "Unspecified device",
2370 path ? path : "N/A");
2371 kfree(objp: path);
2372
2373 error = -EINTR;
2374 scoped_cond_guard(mutex_intr, goto err_device_del, &input_mutex) {
2375 list_add_tail(new: &dev->node, head: &input_dev_list);
2376
2377 list_for_each_entry(handler, &input_handler_list, node)
2378 input_attach_handler(dev, handler);
2379
2380 input_wakeup_procfs_readers();
2381 }
2382
2383 if (dev->devres_managed) {
2384 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2385 __func__, dev_name(&dev->dev));
2386 devres_add(dev: dev->dev.parent, res: devres);
2387 }
2388 return 0;
2389
2390err_device_del:
2391 device_del(dev: &dev->dev);
2392err_devres_free:
2393 devres_free(res: devres);
2394 return error;
2395}
2396EXPORT_SYMBOL(input_register_device);
2397
2398/**
2399 * input_unregister_device - unregister previously registered device
2400 * @dev: device to be unregistered
2401 *
2402 * This function unregisters an input device. Once device is unregistered
2403 * the caller should not try to access it as it may get freed at any moment.
2404 */
2405void input_unregister_device(struct input_dev *dev)
2406{
2407 if (dev->devres_managed) {
2408 WARN_ON(devres_destroy(dev->dev.parent,
2409 devm_input_device_unregister,
2410 devm_input_device_match,
2411 dev));
2412 __input_unregister_device(dev);
2413 /*
2414 * We do not do input_put_device() here because it will be done
2415 * when 2nd devres fires up.
2416 */
2417 } else {
2418 __input_unregister_device(dev);
2419 input_put_device(dev);
2420 }
2421}
2422EXPORT_SYMBOL(input_unregister_device);
2423
2424static int input_handler_check_methods(const struct input_handler *handler)
2425{
2426 int count = 0;
2427
2428 if (handler->filter)
2429 count++;
2430 if (handler->events)
2431 count++;
2432 if (handler->event)
2433 count++;
2434
2435 if (count > 1) {
2436 pr_err("%s: only one event processing method can be defined (%s)\n",
2437 __func__, handler->name);
2438 return -EINVAL;
2439 }
2440
2441 return 0;
2442}
2443
2444/**
2445 * input_register_handler - register a new input handler
2446 * @handler: handler to be registered
2447 *
2448 * This function registers a new input handler (interface) for input
2449 * devices in the system and attaches it to all input devices that
2450 * are compatible with the handler.
2451 */
2452int input_register_handler(struct input_handler *handler)
2453{
2454 struct input_dev *dev;
2455 int error;
2456
2457 error = input_handler_check_methods(handler);
2458 if (error)
2459 return error;
2460
2461 scoped_cond_guard(mutex_intr, return -EINTR, &input_mutex) {
2462 INIT_LIST_HEAD(list: &handler->h_list);
2463
2464 list_add_tail(new: &handler->node, head: &input_handler_list);
2465
2466 list_for_each_entry(dev, &input_dev_list, node)
2467 input_attach_handler(dev, handler);
2468
2469 input_wakeup_procfs_readers();
2470 }
2471
2472 return 0;
2473}
2474EXPORT_SYMBOL(input_register_handler);
2475
2476/**
2477 * input_unregister_handler - unregisters an input handler
2478 * @handler: handler to be unregistered
2479 *
2480 * This function disconnects a handler from its input devices and
2481 * removes it from lists of known handlers.
2482 */
2483void input_unregister_handler(struct input_handler *handler)
2484{
2485 struct input_handle *handle, *next;
2486
2487 guard(mutex)(T: &input_mutex);
2488
2489 list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2490 handler->disconnect(handle);
2491 WARN_ON(!list_empty(&handler->h_list));
2492
2493 list_del_init(entry: &handler->node);
2494
2495 input_wakeup_procfs_readers();
2496}
2497EXPORT_SYMBOL(input_unregister_handler);
2498
2499/**
2500 * input_handler_for_each_handle - handle iterator
2501 * @handler: input handler to iterate
2502 * @data: data for the callback
2503 * @fn: function to be called for each handle
2504 *
2505 * Iterate over @bus's list of devices, and call @fn for each, passing
2506 * it @data and stop when @fn returns a non-zero value. The function is
2507 * using RCU to traverse the list and therefore may be using in atomic
2508 * contexts. The @fn callback is invoked from RCU critical section and
2509 * thus must not sleep.
2510 */
2511int input_handler_for_each_handle(struct input_handler *handler, void *data,
2512 int (*fn)(struct input_handle *, void *))
2513{
2514 struct input_handle *handle;
2515 int retval;
2516
2517 guard(rcu)();
2518
2519 list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2520 retval = fn(handle, data);
2521 if (retval)
2522 return retval;
2523 }
2524
2525 return 0;
2526}
2527EXPORT_SYMBOL(input_handler_for_each_handle);
2528
2529/*
2530 * An implementation of input_handle's handle_events() method that simply
2531 * invokes handler->event() method for each event one by one.
2532 */
2533static unsigned int input_handle_events_default(struct input_handle *handle,
2534 struct input_value *vals,
2535 unsigned int count)
2536{
2537 struct input_handler *handler = handle->handler;
2538 struct input_value *v;
2539
2540 for (v = vals; v != vals + count; v++)
2541 handler->event(handle, v->type, v->code, v->value);
2542
2543 return count;
2544}
2545
2546/*
2547 * An implementation of input_handle's handle_events() method that invokes
2548 * handler->filter() method for each event one by one and removes events
2549 * that were filtered out from the "vals" array.
2550 */
2551static unsigned int input_handle_events_filter(struct input_handle *handle,
2552 struct input_value *vals,
2553 unsigned int count)
2554{
2555 struct input_handler *handler = handle->handler;
2556 struct input_value *end = vals;
2557 struct input_value *v;
2558
2559 for (v = vals; v != vals + count; v++) {
2560 if (handler->filter(handle, v->type, v->code, v->value))
2561 continue;
2562 if (end != v)
2563 *end = *v;
2564 end++;
2565 }
2566
2567 return end - vals;
2568}
2569
2570/*
2571 * An implementation of input_handle's handle_events() method that does nothing.
2572 */
2573static unsigned int input_handle_events_null(struct input_handle *handle,
2574 struct input_value *vals,
2575 unsigned int count)
2576{
2577 return count;
2578}
2579
2580/*
2581 * Sets up appropriate handle->event_handler based on the input_handler
2582 * associated with the handle.
2583 */
2584static void input_handle_setup_event_handler(struct input_handle *handle)
2585{
2586 struct input_handler *handler = handle->handler;
2587
2588 if (handler->filter)
2589 handle->handle_events = input_handle_events_filter;
2590 else if (handler->event)
2591 handle->handle_events = input_handle_events_default;
2592 else if (handler->events)
2593 handle->handle_events = handler->events;
2594 else
2595 handle->handle_events = input_handle_events_null;
2596}
2597
2598/**
2599 * input_register_handle - register a new input handle
2600 * @handle: handle to register
2601 *
2602 * This function puts a new input handle onto device's
2603 * and handler's lists so that events can flow through
2604 * it once it is opened using input_open_device().
2605 *
2606 * This function is supposed to be called from handler's
2607 * connect() method.
2608 */
2609int input_register_handle(struct input_handle *handle)
2610{
2611 struct input_handler *handler = handle->handler;
2612 struct input_dev *dev = handle->dev;
2613
2614 input_handle_setup_event_handler(handle);
2615 /*
2616 * We take dev->mutex here to prevent race with
2617 * input_release_device().
2618 */
2619 scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
2620 /*
2621 * Filters go to the head of the list, normal handlers
2622 * to the tail.
2623 */
2624 if (handler->filter)
2625 list_add_rcu(new: &handle->d_node, head: &dev->h_list);
2626 else
2627 list_add_tail_rcu(new: &handle->d_node, head: &dev->h_list);
2628 }
2629
2630 /*
2631 * Since we are supposed to be called from ->connect()
2632 * which is mutually exclusive with ->disconnect()
2633 * we can't be racing with input_unregister_handle()
2634 * and so separate lock is not needed here.
2635 */
2636 list_add_tail_rcu(new: &handle->h_node, head: &handler->h_list);
2637
2638 if (handler->start)
2639 handler->start(handle);
2640
2641 return 0;
2642}
2643EXPORT_SYMBOL(input_register_handle);
2644
2645/**
2646 * input_unregister_handle - unregister an input handle
2647 * @handle: handle to unregister
2648 *
2649 * This function removes input handle from device's
2650 * and handler's lists.
2651 *
2652 * This function is supposed to be called from handler's
2653 * disconnect() method.
2654 */
2655void input_unregister_handle(struct input_handle *handle)
2656{
2657 struct input_dev *dev = handle->dev;
2658
2659 list_del_rcu(entry: &handle->h_node);
2660
2661 /*
2662 * Take dev->mutex to prevent race with input_release_device().
2663 */
2664 scoped_guard(mutex, &dev->mutex)
2665 list_del_rcu(entry: &handle->d_node);
2666
2667 synchronize_rcu();
2668}
2669EXPORT_SYMBOL(input_unregister_handle);
2670
2671/**
2672 * input_get_new_minor - allocates a new input minor number
2673 * @legacy_base: beginning or the legacy range to be searched
2674 * @legacy_num: size of legacy range
2675 * @allow_dynamic: whether we can also take ID from the dynamic range
2676 *
2677 * This function allocates a new device minor for from input major namespace.
2678 * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2679 * parameters and whether ID can be allocated from dynamic range if there are
2680 * no free IDs in legacy range.
2681 */
2682int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2683 bool allow_dynamic)
2684{
2685 /*
2686 * This function should be called from input handler's ->connect()
2687 * methods, which are serialized with input_mutex, so no additional
2688 * locking is needed here.
2689 */
2690 if (legacy_base >= 0) {
2691 int minor = ida_alloc_range(&input_ida, min: legacy_base,
2692 max: legacy_base + legacy_num - 1,
2693 GFP_KERNEL);
2694 if (minor >= 0 || !allow_dynamic)
2695 return minor;
2696 }
2697
2698 return ida_alloc_range(&input_ida, INPUT_FIRST_DYNAMIC_DEV,
2699 INPUT_MAX_CHAR_DEVICES - 1, GFP_KERNEL);
2700}
2701EXPORT_SYMBOL(input_get_new_minor);
2702
2703/**
2704 * input_free_minor - release previously allocated minor
2705 * @minor: minor to be released
2706 *
2707 * This function releases previously allocated input minor so that it can be
2708 * reused later.
2709 */
2710void input_free_minor(unsigned int minor)
2711{
2712 ida_free(&input_ida, id: minor);
2713}
2714EXPORT_SYMBOL(input_free_minor);
2715
2716static int __init input_init(void)
2717{
2718 int err;
2719
2720 err = class_register(class: &input_class);
2721 if (err) {
2722 pr_err("unable to register input_dev class\n");
2723 return err;
2724 }
2725
2726 err = input_proc_init();
2727 if (err)
2728 goto fail1;
2729
2730 err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2731 INPUT_MAX_CHAR_DEVICES, "input");
2732 if (err) {
2733 pr_err("unable to register char major %d", INPUT_MAJOR);
2734 goto fail2;
2735 }
2736
2737 return 0;
2738
2739 fail2: input_proc_exit();
2740 fail1: class_unregister(class: &input_class);
2741 return err;
2742}
2743
2744static void __exit input_exit(void)
2745{
2746 input_proc_exit();
2747 unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2748 INPUT_MAX_CHAR_DEVICES);
2749 class_unregister(class: &input_class);
2750}
2751
2752subsys_initcall(input_init);
2753module_exit(input_exit);
2754