1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* The input core
4	*
5	* Copyright (c) 1999-2002 Vojtech Pavlik
6	*/
7
8
9	#define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
10
11	#include <linux/init.h>
12	#include <linux/types.h>
13	#include <linux/idr.h>
14	#include <linux/input/mt.h>
15	#include <linux/module.h>
16	#include <linux/slab.h>
17	#include <linux/random.h>
18	#include <linux/major.h>
19	#include <linux/proc_fs.h>
20	#include <linux/sched.h>
21	#include <linux/seq_file.h>
22	#include <linux/pm.h>
23	#include <linux/poll.h>
24	#include <linux/device.h>
25	#include <linux/kstrtox.h>
26	#include <linux/mutex.h>
27	#include <linux/rcupdate.h>
28	#include "input-compat.h"
29	#include "input-core-private.h"
30	#include "input-poller.h"
31
32	MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
33	MODULE_DESCRIPTION("Input core");
34	MODULE_LICENSE("GPL");
35
36	#define INPUT_MAX_CHAR_DEVICES 1024
37	#define INPUT_FIRST_DYNAMIC_DEV 256
38	static DEFINE_IDA(input_ida);
39
40	static LIST_HEAD(input_dev_list);
41	static LIST_HEAD(input_handler_list);
42
43	/*
44	* input_mutex protects access to both input_dev_list and input_handler_list.
45	* This also causes input_[un]register_device and input_[un]register_handler
46	* be mutually exclusive which simplifies locking in drivers implementing
47	* input handlers.
48	*/
49	static DEFINE_MUTEX(input_mutex);
50
51	static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
52
53	static const unsigned int input_max_code[EV_CNT] = {
54	[EV_KEY] = KEY_MAX,
55	[EV_REL] = REL_MAX,
56	[EV_ABS] = ABS_MAX,
57	[EV_MSC] = MSC_MAX,
58	[EV_SW] = SW_MAX,
59	[EV_LED] = LED_MAX,
60	[EV_SND] = SND_MAX,
61	[EV_FF] = FF_MAX,
62	};
63
64	static inline int is_event_supported(unsigned int code,
65	unsigned long *bm, unsigned int max)
66	{
67	return code <= max && test_bit(code, bm);
68	}
69
70	static int input_defuzz_abs_event(int value, int old_val, int fuzz)
71	{
72	if (fuzz) {
73	if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
74	return old_val;
75
76	if (value > old_val - fuzz && value < old_val + fuzz)
77	return (old_val * 3 + value) / 4;
78
79	if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
80	return (old_val + value) / 2;
81	}
82
83	return value;
84	}
85
86	static void input_start_autorepeat(struct input_dev *dev, int code)
87	{
88	if (test_bit(EV_REP, dev->evbit) &&
89	dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
90	dev->timer.function) {
91	dev->repeat_key = code;
92	mod_timer(timer: &dev->timer,
93	expires: jiffies + msecs_to_jiffies(m: dev->rep[REP_DELAY]));
94	}
95	}
96
97	static void input_stop_autorepeat(struct input_dev *dev)
98	{
99	timer_delete(timer: &dev->timer);
100	}
101
102	/*
103	* Pass values first through all filters and then, if event has not been
104	* filtered out, through all open handles. This order is achieved by placing
105	* filters at the head of the list of handles attached to the device, and
106	* placing regular handles at the tail of the list.
107	*
108	* This function is called with dev->event_lock held and interrupts disabled.
109	*/
110	static void input_pass_values(struct input_dev *dev,
111	struct input_value *vals, unsigned int count)
112	{
113	struct input_handle *handle;
114	struct input_value *v;
115
116	lockdep_assert_held(&dev->event_lock);
117
118	scoped_guard(rcu) {
119	handle = rcu_dereference(dev->grab);
120	if (handle) {
121	count = handle->handle_events(handle, vals, count);
122	break;
123	}
124
125	list_for_each_entry_rcu(handle, &dev->h_list, d_node) {
126	if (handle->open) {
127	count = handle->handle_events(handle, vals,
128	count);
129	if (!count)
130	break;
131	}
132	}
133	}
134
135	/* trigger auto repeat for key events */
136	if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
137	for (v = vals; v != vals + count; v++) {
138	if (v->type == EV_KEY && v->value != 2) {
139	if (v->value)
140	input_start_autorepeat(dev, code: v->code);
141	else
142	input_stop_autorepeat(dev);
143	}
144	}
145	}
146	}
147
148	#define INPUT_IGNORE_EVENT 0
149	#define INPUT_PASS_TO_HANDLERS 1
150	#define INPUT_PASS_TO_DEVICE 2
151	#define INPUT_SLOT 4
152	#define INPUT_FLUSH 8
153	#define INPUT_PASS_TO_ALL (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
154
155	static int input_handle_abs_event(struct input_dev *dev,
156	unsigned int code, int *pval)
157	{
158	struct input_mt *mt = dev->mt;
159	bool is_new_slot = false;
160	bool is_mt_event;
161	int *pold;
162
163	if (code == ABS_MT_SLOT) {
164	/*
165	* "Stage" the event; we'll flush it later, when we
166	* get actual touch data.
167	*/
168	if (mt && *pval >= 0 && *pval < mt->num_slots)
169	mt->slot = *pval;
170
171	return INPUT_IGNORE_EVENT;
172	}
173
174	is_mt_event = input_is_mt_value(axis: code);
175
176	if (!is_mt_event) {
177	pold = &dev->absinfo[code].value;
178	} else if (mt) {
179	pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
180	is_new_slot = mt->slot != dev->absinfo[ABS_MT_SLOT].value;
181	} else {
182	/*
183	* Bypass filtering for multi-touch events when
184	* not employing slots.
185	*/
186	pold = NULL;
187	}
188
189	if (pold) {
190	*pval = input_defuzz_abs_event(value: *pval, old_val: *pold,
191	fuzz: dev->absinfo[code].fuzz);
192	if (*pold == *pval)
193	return INPUT_IGNORE_EVENT;
194
195	*pold = *pval;
196	}
197
198	/* Flush pending "slot" event */
199	if (is_new_slot) {
200	dev->absinfo[ABS_MT_SLOT].value = mt->slot;
201	return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
202	}
203
204	return INPUT_PASS_TO_HANDLERS;
205	}
206
207	static int input_get_disposition(struct input_dev *dev,
208	unsigned int type, unsigned int code, int *pval)
209	{
210	int disposition = INPUT_IGNORE_EVENT;
211	int value = *pval;
212
213	/* filter-out events from inhibited devices */
214	if (dev->inhibited)
215	return INPUT_IGNORE_EVENT;
216
217	switch (type) {
218
219	case EV_SYN:
220	switch (code) {
221	case SYN_CONFIG:
222	disposition = INPUT_PASS_TO_ALL;
223	break;
224
225	case SYN_REPORT:
226	disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
227	break;
228	case SYN_MT_REPORT:
229	disposition = INPUT_PASS_TO_HANDLERS;
230	break;
231	}
232	break;
233
234	case EV_KEY:
235	if (is_event_supported(code, bm: dev->keybit, KEY_MAX)) {
236
237	/* auto-repeat bypasses state updates */
238	if (value == 2) {
239	disposition = INPUT_PASS_TO_HANDLERS;
240	break;
241	}
242
243	if (!!test_bit(code, dev->key) != !!value) {
244
245	__change_bit(code, dev->key);
246	disposition = INPUT_PASS_TO_HANDLERS;
247	}
248	}
249	break;
250
251	case EV_SW:
252	if (is_event_supported(code, bm: dev->swbit, SW_MAX) &&
253	!!test_bit(code, dev->sw) != !!value) {
254
255	__change_bit(code, dev->sw);
256	disposition = INPUT_PASS_TO_HANDLERS;
257	}
258	break;
259
260	case EV_ABS:
261	if (is_event_supported(code, bm: dev->absbit, ABS_MAX))
262	disposition = input_handle_abs_event(dev, code, pval: &value);
263
264	break;
265
266	case EV_REL:
267	if (is_event_supported(code, bm: dev->relbit, REL_MAX) && value)
268	disposition = INPUT_PASS_TO_HANDLERS;
269
270	break;
271
272	case EV_MSC:
273	if (is_event_supported(code, bm: dev->mscbit, MSC_MAX))
274	disposition = INPUT_PASS_TO_ALL;
275
276	break;
277
278	case EV_LED:
279	if (is_event_supported(code, bm: dev->ledbit, LED_MAX) &&
280	!!test_bit(code, dev->led) != !!value) {
281
282	__change_bit(code, dev->led);
283	disposition = INPUT_PASS_TO_ALL;
284	}
285	break;
286
287	case EV_SND:
288	if (is_event_supported(code, bm: dev->sndbit, SND_MAX)) {
289
290	if (!!test_bit(code, dev->snd) != !!value)
291	__change_bit(code, dev->snd);
292	disposition = INPUT_PASS_TO_ALL;
293	}
294	break;
295
296	case EV_REP:
297	if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
298	dev->rep[code] = value;
299	disposition = INPUT_PASS_TO_ALL;
300	}
301	break;
302
303	case EV_FF:
304	if (value >= 0)
305	disposition = INPUT_PASS_TO_ALL;
306	break;
307
308	case EV_PWR:
309	disposition = INPUT_PASS_TO_ALL;
310	break;
311	}
312
313	*pval = value;
314	return disposition;
315	}
316
317	static void input_event_dispose(struct input_dev *dev, int disposition,
318	unsigned int type, unsigned int code, int value)
319	{
320	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
321	dev->event(dev, type, code, value);
322
323	if (disposition & INPUT_PASS_TO_HANDLERS) {
324	struct input_value *v;
325
326	if (disposition & INPUT_SLOT) {
327	v = &dev->vals[dev->num_vals++];
328	v->type = EV_ABS;
329	v->code = ABS_MT_SLOT;
330	v->value = dev->mt->slot;
331	}
332
333	v = &dev->vals[dev->num_vals++];
334	v->type = type;
335	v->code = code;
336	v->value = value;
337	}
338
339	if (disposition & INPUT_FLUSH) {
340	if (dev->num_vals >= 2)
341	input_pass_values(dev, vals: dev->vals, count: dev->num_vals);
342	dev->num_vals = 0;
343	/*
344	* Reset the timestamp on flush so we won't end up
345	* with a stale one. Note we only need to reset the
346	* monolithic one as we use its presence when deciding
347	* whether to generate a synthetic timestamp.
348	*/
349	dev->timestamp[INPUT_CLK_MONO] = ktime_set(secs: 0, nsecs: 0);
350	} else if (dev->num_vals >= dev->max_vals - 2) {
351	dev->vals[dev->num_vals++] = input_value_sync;
352	input_pass_values(dev, vals: dev->vals, count: dev->num_vals);
353	dev->num_vals = 0;
354	}
355	}
356
357	void input_handle_event(struct input_dev *dev,
358	unsigned int type, unsigned int code, int value)
359	{
360	int disposition;
361
362	lockdep_assert_held(&dev->event_lock);
363
364	disposition = input_get_disposition(dev, type, code, pval: &value);
365	if (disposition != INPUT_IGNORE_EVENT) {
366	if (type != EV_SYN)
367	add_input_randomness(type, code, value);
368
369	input_event_dispose(dev, disposition, type, code, value);
370	}
371	}
372
373	/**
374	* input_event() - report new input event
375	* @dev: device that generated the event
376	* @type: type of the event
377	* @code: event code
378	* @value: value of the event
379	*
380	* This function should be used by drivers implementing various input
381	* devices to report input events. See also input_inject_event().
382	*
383	* NOTE: input_event() may be safely used right after input device was
384	* allocated with input_allocate_device(), even before it is registered
385	* with input_register_device(), but the event will not reach any of the
386	* input handlers. Such early invocation of input_event() may be used
387	* to 'seed' initial state of a switch or initial position of absolute
388	* axis, etc.
389	*/
390	void input_event(struct input_dev *dev,
391	unsigned int type, unsigned int code, int value)
392	{
393	if (is_event_supported(code: type, bm: dev->evbit, EV_MAX)) {
394	guard(spinlock_irqsave)(l: &dev->event_lock);
395	input_handle_event(dev, type, code, value);
396	}
397	}
398	EXPORT_SYMBOL(input_event);
399
400	/**
401	* input_inject_event() - send input event from input handler
402	* @handle: input handle to send event through
403	* @type: type of the event
404	* @code: event code
405	* @value: value of the event
406	*
407	* Similar to input_event() but will ignore event if device is
408	* "grabbed" and handle injecting event is not the one that owns
409	* the device.
410	*/
411	void input_inject_event(struct input_handle *handle,
412	unsigned int type, unsigned int code, int value)
413	{
414	struct input_dev *dev = handle->dev;
415	struct input_handle *grab;
416
417	if (is_event_supported(code: type, bm: dev->evbit, EV_MAX)) {
418	guard(spinlock_irqsave)(l: &dev->event_lock);
419	guard(rcu)();
420
421	grab = rcu_dereference(dev->grab);
422	if (!grab || grab == handle)
423	input_handle_event(dev, type, code, value);
424
425	}
426	}
427	EXPORT_SYMBOL(input_inject_event);
428
429	/**
430	* input_alloc_absinfo - allocates array of input_absinfo structs
431	* @dev: the input device emitting absolute events
432	*
433	* If the absinfo struct the caller asked for is already allocated, this
434	* functions will not do anything.
435	*/
436	void input_alloc_absinfo(struct input_dev *dev)
437	{
438	if (dev->absinfo)
439	return;
440
441	dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
442	if (!dev->absinfo) {
443	dev_err(dev->dev.parent ?: &dev->dev,
444	"%s: unable to allocate memory\n", __func__);
445	/*
446	* We will handle this allocation failure in
447	* input_register_device() when we refuse to register input
448	* device with ABS bits but without absinfo.
449	*/
450	}
451	}
452	EXPORT_SYMBOL(input_alloc_absinfo);
453
454	void input_set_abs_params(struct input_dev *dev, unsigned int axis,
455	int min, int max, int fuzz, int flat)
456	{
457	struct input_absinfo *absinfo;
458
459	__set_bit(EV_ABS, dev->evbit);
460	__set_bit(axis, dev->absbit);
461
462	input_alloc_absinfo(dev);
463	if (!dev->absinfo)
464	return;
465
466	absinfo = &dev->absinfo[axis];
467	absinfo->minimum = min;
468	absinfo->maximum = max;
469	absinfo->fuzz = fuzz;
470	absinfo->flat = flat;
471	}
472	EXPORT_SYMBOL(input_set_abs_params);
473
474	/**
475	* input_copy_abs - Copy absinfo from one input_dev to another
476	* @dst: Destination input device to copy the abs settings to
477	* @dst_axis: ABS_* value selecting the destination axis
478	* @src: Source input device to copy the abs settings from
479	* @src_axis: ABS_* value selecting the source axis
480	*
481	* Set absinfo for the selected destination axis by copying it from
482	* the specified source input device's source axis.
483	* This is useful to e.g. setup a pen/stylus input-device for combined
484	* touchscreen/pen hardware where the pen uses the same coordinates as
485	* the touchscreen.
486	*/
487	void input_copy_abs(struct input_dev *dst, unsigned int dst_axis,
488	const struct input_dev *src, unsigned int src_axis)
489	{
490	/* src must have EV_ABS and src_axis set */
491	if (WARN_ON(!(test_bit(EV_ABS, src->evbit) &&
492	test_bit(src_axis, src->absbit))))
493	return;
494
495	/*
496	* input_alloc_absinfo() may have failed for the source. Our caller is
497	* expected to catch this when registering the input devices, which may
498	* happen after the input_copy_abs() call.
499	*/
500	if (!src->absinfo)
501	return;
502
503	input_set_capability(dev: dst, EV_ABS, code: dst_axis);
504	if (!dst->absinfo)
505	return;
506
507	dst->absinfo[dst_axis] = src->absinfo[src_axis];
508	}
509	EXPORT_SYMBOL(input_copy_abs);
510
511	/**
512	* input_grab_device - grabs device for exclusive use
513	* @handle: input handle that wants to own the device
514	*
515	* When a device is grabbed by an input handle all events generated by
516	* the device are delivered only to this handle. Also events injected
517	* by other input handles are ignored while device is grabbed.
518	*/
519	int input_grab_device(struct input_handle *handle)
520	{
521	struct input_dev *dev = handle->dev;
522
523	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
524	if (dev->grab)
525	return -EBUSY;
526
527	rcu_assign_pointer(dev->grab, handle);
528	}
529
530	return 0;
531	}
532	EXPORT_SYMBOL(input_grab_device);
533
534	static void __input_release_device(struct input_handle *handle)
535	{
536	struct input_dev *dev = handle->dev;
537	struct input_handle *grabber;
538
539	grabber = rcu_dereference_protected(dev->grab,
540	lockdep_is_held(&dev->mutex));
541	if (grabber == handle) {
542	rcu_assign_pointer(dev->grab, NULL);
543	/* Make sure input_pass_values() notices that grab is gone */
544	synchronize_rcu();
545
546	list_for_each_entry(handle, &dev->h_list, d_node)
547	if (handle->open && handle->handler->start)
548	handle->handler->start(handle);
549	}
550	}
551
552	/**
553	* input_release_device - release previously grabbed device
554	* @handle: input handle that owns the device
555	*
556	* Releases previously grabbed device so that other input handles can
557	* start receiving input events. Upon release all handlers attached
558	* to the device have their start() method called so they have a change
559	* to synchronize device state with the rest of the system.
560	*/
561	void input_release_device(struct input_handle *handle)
562	{
563	struct input_dev *dev = handle->dev;
564
565	guard(mutex)(T: &dev->mutex);
566	__input_release_device(handle);
567	}
568	EXPORT_SYMBOL(input_release_device);
569
570	/**
571	* input_open_device - open input device
572	* @handle: handle through which device is being accessed
573	*
574	* This function should be called by input handlers when they
575	* want to start receive events from given input device.
576	*/
577	int input_open_device(struct input_handle *handle)
578	{
579	struct input_dev *dev = handle->dev;
580	int error;
581
582	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
583	if (dev->going_away)
584	return -ENODEV;
585
586	handle->open++;
587
588	if (handle->handler->passive_observer)
589	return 0;
590
591	if (dev->users++ || dev->inhibited) {
592	/*
593	* Device is already opened and/or inhibited,
594	* so we can exit immediately and report success.
595	*/
596	return 0;
597	}
598
599	if (dev->open) {
600	error = dev->open(dev);
601	if (error) {
602	dev->users--;
603	handle->open--;
604	/*
605	* Make sure we are not delivering any more
606	* events through this handle.
607	*/
608	synchronize_rcu();
609	return error;
610	}
611	}
612
613	if (dev->poller)
614	input_dev_poller_start(poller: dev->poller);
615	}
616
617	return 0;
618	}
619	EXPORT_SYMBOL(input_open_device);
620
621	int input_flush_device(struct input_handle *handle, struct file *file)
622	{
623	struct input_dev *dev = handle->dev;
624
625	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
626	if (dev->flush)
627	return dev->flush(dev, file);
628	}
629
630	return 0;
631	}
632	EXPORT_SYMBOL(input_flush_device);
633
634	/**
635	* input_close_device - close input device
636	* @handle: handle through which device is being accessed
637	*
638	* This function should be called by input handlers when they
639	* want to stop receive events from given input device.
640	*/
641	void input_close_device(struct input_handle *handle)
642	{
643	struct input_dev *dev = handle->dev;
644
645	guard(mutex)(T: &dev->mutex);
646
647	__input_release_device(handle);
648
649	if (!handle->handler->passive_observer) {
650	if (!--dev->users && !dev->inhibited) {
651	if (dev->poller)
652	input_dev_poller_stop(poller: dev->poller);
653	if (dev->close)
654	dev->close(dev);
655	}
656	}
657
658	if (!--handle->open) {
659	/*
660	* synchronize_rcu() makes sure that input_pass_values()
661	* completed and that no more input events are delivered
662	* through this handle
663	*/
664	synchronize_rcu();
665	}
666	}
667	EXPORT_SYMBOL(input_close_device);
668
669	/*
670	* Simulate keyup events for all keys that are marked as pressed.
671	* The function must be called with dev->event_lock held.
672	*/
673	static bool input_dev_release_keys(struct input_dev *dev)
674	{
675	bool need_sync = false;
676	int code;
677
678	lockdep_assert_held(&dev->event_lock);
679
680	if (is_event_supported(EV_KEY, bm: dev->evbit, EV_MAX)) {
681	for_each_set_bit(code, dev->key, KEY_CNT) {
682	input_handle_event(dev, EV_KEY, code, value: 0);
683	need_sync = true;
684	}
685	}
686
687	return need_sync;
688	}
689
690	/*
691	* Prepare device for unregistering
692	*/
693	static void input_disconnect_device(struct input_dev *dev)
694	{
695	struct input_handle *handle;
696
697	/*
698	* Mark device as going away. Note that we take dev->mutex here
699	* not to protect access to dev->going_away but rather to ensure
700	* that there are no threads in the middle of input_open_device()
701	*/
702	scoped_guard(mutex, &dev->mutex)
703	dev->going_away = true;
704
705	guard(spinlock_irq)(l: &dev->event_lock);
706
707	/*
708	* Simulate keyup events for all pressed keys so that handlers
709	* are not left with "stuck" keys. The driver may continue
710	* generate events even after we done here but they will not
711	* reach any handlers.
712	*/
713	if (input_dev_release_keys(dev))
714	input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
715
716	list_for_each_entry(handle, &dev->h_list, d_node)
717	handle->open = 0;
718	}
719
720	/**
721	* input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
722	* @ke: keymap entry containing scancode to be converted.
723	* @scancode: pointer to the location where converted scancode should
724	* be stored.
725	*
726	* This function is used to convert scancode stored in &struct keymap_entry
727	* into scalar form understood by legacy keymap handling methods. These
728	* methods expect scancodes to be represented as 'unsigned int'.
729	*/
730	int input_scancode_to_scalar(const struct input_keymap_entry *ke,
731	unsigned int *scancode)
732	{
733	switch (ke->len) {
734	case 1:
735	*scancode = *((u8 *)ke->scancode);
736	break;
737
738	case 2:
739	*scancode = *((u16 *)ke->scancode);
740	break;
741
742	case 4:
743	*scancode = *((u32 *)ke->scancode);
744	break;
745
746	default:
747	return -EINVAL;
748	}
749
750	return 0;
751	}
752	EXPORT_SYMBOL(input_scancode_to_scalar);
753
754	/*
755	* Those routines handle the default case where no [gs]etkeycode() is
756	* defined. In this case, an array indexed by the scancode is used.
757	*/
758
759	static unsigned int input_fetch_keycode(struct input_dev *dev,
760	unsigned int index)
761	{
762	switch (dev->keycodesize) {
763	case 1:
764	return ((u8 *)dev->keycode)[index];
765
766	case 2:
767	return ((u16 *)dev->keycode)[index];
768
769	default:
770	return ((u32 *)dev->keycode)[index];
771	}
772	}
773
774	static int input_default_getkeycode(struct input_dev *dev,
775	struct input_keymap_entry *ke)
776	{
777	unsigned int index;
778	int error;
779
780	if (!dev->keycodesize)
781	return -EINVAL;
782
783	if (ke->flags & INPUT_KEYMAP_BY_INDEX)
784	index = ke->index;
785	else {
786	error = input_scancode_to_scalar(ke, &index);
787	if (error)
788	return error;
789	}
790
791	if (index >= dev->keycodemax)
792	return -EINVAL;
793
794	ke->keycode = input_fetch_keycode(dev, index);
795	ke->index = index;
796	ke->len = sizeof(index);
797	memcpy(ke->scancode, &index, sizeof(index));
798
799	return 0;
800	}
801
802	static int input_default_setkeycode(struct input_dev *dev,
803	const struct input_keymap_entry *ke,
804	unsigned int *old_keycode)
805	{
806	unsigned int index;
807	int error;
808	int i;
809
810	if (!dev->keycodesize)
811	return -EINVAL;
812
813	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
814	index = ke->index;
815	} else {
816	error = input_scancode_to_scalar(ke, &index);
817	if (error)
818	return error;
819	}
820
821	if (index >= dev->keycodemax)
822	return -EINVAL;
823
824	if (dev->keycodesize < sizeof(ke->keycode) &&
825	(ke->keycode >> (dev->keycodesize * 8)))
826	return -EINVAL;
827
828	switch (dev->keycodesize) {
829	case 1: {
830	u8 *k = (u8 *)dev->keycode;
831	*old_keycode = k[index];
832	k[index] = ke->keycode;
833	break;
834	}
835	case 2: {
836	u16 *k = (u16 *)dev->keycode;
837	*old_keycode = k[index];
838	k[index] = ke->keycode;
839	break;
840	}
841	default: {
842	u32 *k = (u32 *)dev->keycode;
843	*old_keycode = k[index];
844	k[index] = ke->keycode;
845	break;
846	}
847	}
848
849	if (*old_keycode <= KEY_MAX) {
850	__clear_bit(*old_keycode, dev->keybit);
851	for (i = 0; i < dev->keycodemax; i++) {
852	if (input_fetch_keycode(dev, index: i) == *old_keycode) {
853	__set_bit(*old_keycode, dev->keybit);
854	/* Setting the bit twice is useless, so break */
855	break;
856	}
857	}
858	}
859
860	__set_bit(ke->keycode, dev->keybit);
861	return 0;
862	}
863
864	/**
865	* input_get_keycode - retrieve keycode currently mapped to a given scancode
866	* @dev: input device which keymap is being queried
867	* @ke: keymap entry
868	*
869	* This function should be called by anyone interested in retrieving current
870	* keymap. Presently evdev handlers use it.
871	*/
872	int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
873	{
874	guard(spinlock_irqsave)(l: &dev->event_lock);
875
876	return dev->getkeycode(dev, ke);
877	}
878	EXPORT_SYMBOL(input_get_keycode);
879
880	/**
881	* input_set_keycode - attribute a keycode to a given scancode
882	* @dev: input device which keymap is being updated
883	* @ke: new keymap entry
884	*
885	* This function should be called by anyone needing to update current
886	* keymap. Presently keyboard and evdev handlers use it.
887	*/
888	int input_set_keycode(struct input_dev *dev,
889	const struct input_keymap_entry *ke)
890	{
891	unsigned int old_keycode;
892	int error;
893
894	if (ke->keycode > KEY_MAX)
895	return -EINVAL;
896
897	guard(spinlock_irqsave)(l: &dev->event_lock);
898
899	error = dev->setkeycode(dev, ke, &old_keycode);
900	if (error)
901	return error;
902
903	/* Make sure KEY_RESERVED did not get enabled. */
904	__clear_bit(KEY_RESERVED, dev->keybit);
905
906	/*
907	* Simulate keyup event if keycode is not present
908	* in the keymap anymore
909	*/
910	if (old_keycode > KEY_MAX) {
911	dev_warn(dev->dev.parent ?: &dev->dev,
912	"%s: got too big old keycode %#x\n",
913	__func__, old_keycode);
914	} else if (test_bit(EV_KEY, dev->evbit) &&
915	!is_event_supported(code: old_keycode, bm: dev->keybit, KEY_MAX) &&
916	__test_and_clear_bit(old_keycode, dev->key)) {
917	/*
918	* We have to use input_event_dispose() here directly instead
919	* of input_handle_event() because the key we want to release
920	* here is considered no longer supported by the device and
921	* input_handle_event() will ignore it.
922	*/
923	input_event_dispose(dev, INPUT_PASS_TO_HANDLERS,
924	EV_KEY, code: old_keycode, value: 0);
925	input_event_dispose(dev, INPUT_PASS_TO_HANDLERS | INPUT_FLUSH,
926	EV_SYN, SYN_REPORT, value: 1);
927	}
928
929	return 0;
930	}
931	EXPORT_SYMBOL(input_set_keycode);
932
933	bool input_match_device_id(const struct input_dev *dev,
934	const struct input_device_id *id)
935	{
936	if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
937	if (id->bustype != dev->id.bustype)
938	return false;
939
940	if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
941	if (id->vendor != dev->id.vendor)
942	return false;
943
944	if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
945	if (id->product != dev->id.product)
946	return false;
947
948	if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
949	if (id->version != dev->id.version)
950	return false;
951
952	if (!bitmap_subset(src1: id->evbit, src2: dev->evbit, EV_MAX) ||
953	!bitmap_subset(src1: id->keybit, src2: dev->keybit, KEY_MAX) ||
954	!bitmap_subset(src1: id->relbit, src2: dev->relbit, REL_MAX) ||
955	!bitmap_subset(src1: id->absbit, src2: dev->absbit, ABS_MAX) ||
956	!bitmap_subset(src1: id->mscbit, src2: dev->mscbit, MSC_MAX) ||
957	!bitmap_subset(src1: id->ledbit, src2: dev->ledbit, LED_MAX) ||
958	!bitmap_subset(src1: id->sndbit, src2: dev->sndbit, SND_MAX) ||
959	!bitmap_subset(src1: id->ffbit, src2: dev->ffbit, FF_MAX) ||
960	!bitmap_subset(src1: id->swbit, src2: dev->swbit, SW_MAX) ||
961	!bitmap_subset(src1: id->propbit, src2: dev->propbit, INPUT_PROP_MAX)) {
962	return false;
963	}
964
965	return true;
966	}
967	EXPORT_SYMBOL(input_match_device_id);
968
969	static const struct input_device_id *input_match_device(struct input_handler *handler,
970	struct input_dev *dev)
971	{
972	const struct input_device_id *id;
973
974	for (id = handler->id_table; id->flags || id->driver_info; id++) {
975	if (input_match_device_id(dev, id) &&
976	(!handler->match || handler->match(handler, dev))) {
977	return id;
978	}
979	}
980
981	return NULL;
982	}
983
984	static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
985	{
986	const struct input_device_id *id;
987	int error;
988
989	id = input_match_device(handler, dev);
990	if (!id)
991	return -ENODEV;
992
993	error = handler->connect(handler, dev, id);
994	if (error && error != -ENODEV)
995	pr_err("failed to attach handler %s to device %s, error: %d\n",
996	handler->name, kobject_name(&dev->dev.kobj), error);
997
998	return error;
999	}
1000
1001	#ifdef CONFIG_COMPAT
1002
1003	static int input_bits_to_string(char *buf, int buf_size,
1004	unsigned long bits, bool skip_empty)
1005	{
1006	int len = 0;
1007
1008	if (in_compat_syscall()) {
1009	u32 dword = bits >> 32;
1010	if (dword || !skip_empty)
1011	len += snprintf(buf, size: buf_size, fmt: "%x ", dword);
1012
1013	dword = bits & 0xffffffffUL;
1014	if (dword || !skip_empty || len)
1015	len += snprintf(buf: buf + len, max(buf_size - len, 0),
1016	fmt: "%x", dword);
1017	} else {
1018	if (bits || !skip_empty)
1019	len += snprintf(buf, size: buf_size, fmt: "%lx", bits);
1020	}
1021
1022	return len;
1023	}
1024
1025	#else /* !CONFIG_COMPAT */
1026
1027	static int input_bits_to_string(char *buf, int buf_size,
1028	unsigned long bits, bool skip_empty)
1029	{
1030	return bits || !skip_empty ?
1031	snprintf(buf, buf_size, "%lx", bits) : 0;
1032	}
1033
1034	#endif
1035
1036	#ifdef CONFIG_PROC_FS
1037
1038	static struct proc_dir_entry *proc_bus_input_dir;
1039	static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1040	static int input_devices_state;
1041
1042	static inline void input_wakeup_procfs_readers(void)
1043	{
1044	input_devices_state++;
1045	wake_up(&input_devices_poll_wait);
1046	}
1047
1048	struct input_seq_state {
1049	unsigned short pos;
1050	bool mutex_acquired;
1051	int input_devices_state;
1052	};
1053
1054	static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1055	{
1056	struct seq_file *seq = file->private_data;
1057	struct input_seq_state *state = seq->private;
1058
1059	poll_wait(filp: file, wait_address: &input_devices_poll_wait, p: wait);
1060	if (state->input_devices_state != input_devices_state) {
1061	state->input_devices_state = input_devices_state;
1062	return EPOLLIN | EPOLLRDNORM;
1063	}
1064
1065	return 0;
1066	}
1067
1068	static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1069	{
1070	struct input_seq_state *state = seq->private;
1071	int error;
1072
1073	error = mutex_lock_interruptible(&input_mutex);
1074	if (error) {
1075	state->mutex_acquired = false;
1076	return ERR_PTR(error);
1077	}
1078
1079	state->mutex_acquired = true;
1080
1081	return seq_list_start(head: &input_dev_list, pos: *pos);
1082	}
1083
1084	static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1085	{
1086	return seq_list_next(v, head: &input_dev_list, ppos: pos);
1087	}
1088
1089	static void input_seq_stop(struct seq_file *seq, void *v)
1090	{
1091	struct input_seq_state *state = seq->private;
1092
1093	if (state->mutex_acquired)
1094	mutex_unlock(lock: &input_mutex);
1095	}
1096
1097	static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1098	unsigned long *bitmap, int max)
1099	{
1100	int i;
1101	bool skip_empty = true;
1102	char buf[18];
1103
1104	seq_printf(m: seq, fmt: "B: %s=", name);
1105
1106	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1107	if (input_bits_to_string(buf, buf_size: sizeof(buf),
1108	bits: bitmap[i], skip_empty)) {
1109	skip_empty = false;
1110	seq_printf(m: seq, fmt: "%s%s", buf, i > 0 ? " " : "");
1111	}
1112	}
1113
1114	/*
1115	* If no output was produced print a single 0.
1116	*/
1117	if (skip_empty)
1118	seq_putc(m: seq, c: '0');
1119
1120	seq_putc(m: seq, c: '\n');
1121	}
1122
1123	static int input_devices_seq_show(struct seq_file *seq, void *v)
1124	{
1125	struct input_dev *dev = container_of(v, struct input_dev, node);
1126	const char *path = kobject_get_path(kobj: &dev->dev.kobj, GFP_KERNEL);
1127	struct input_handle *handle;
1128
1129	seq_printf(m: seq, fmt: "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1130	dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1131
1132	seq_printf(m: seq, fmt: "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1133	seq_printf(m: seq, fmt: "P: Phys=%s\n", dev->phys ? dev->phys : "");
1134	seq_printf(m: seq, fmt: "S: Sysfs=%s\n", path ? path : "");
1135	seq_printf(m: seq, fmt: "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1136	seq_puts(m: seq, s: "H: Handlers=");
1137
1138	list_for_each_entry(handle, &dev->h_list, d_node)
1139	seq_printf(m: seq, fmt: "%s ", handle->name);
1140	seq_putc(m: seq, c: '\n');
1141
1142	input_seq_print_bitmap(seq, name: "PROP", bitmap: dev->propbit, INPUT_PROP_MAX);
1143
1144	input_seq_print_bitmap(seq, name: "EV", bitmap: dev->evbit, EV_MAX);
1145	if (test_bit(EV_KEY, dev->evbit))
1146	input_seq_print_bitmap(seq, name: "KEY", bitmap: dev->keybit, KEY_MAX);
1147	if (test_bit(EV_REL, dev->evbit))
1148	input_seq_print_bitmap(seq, name: "REL", bitmap: dev->relbit, REL_MAX);
1149	if (test_bit(EV_ABS, dev->evbit))
1150	input_seq_print_bitmap(seq, name: "ABS", bitmap: dev->absbit, ABS_MAX);
1151	if (test_bit(EV_MSC, dev->evbit))
1152	input_seq_print_bitmap(seq, name: "MSC", bitmap: dev->mscbit, MSC_MAX);
1153	if (test_bit(EV_LED, dev->evbit))
1154	input_seq_print_bitmap(seq, name: "LED", bitmap: dev->ledbit, LED_MAX);
1155	if (test_bit(EV_SND, dev->evbit))
1156	input_seq_print_bitmap(seq, name: "SND", bitmap: dev->sndbit, SND_MAX);
1157	if (test_bit(EV_FF, dev->evbit))
1158	input_seq_print_bitmap(seq, name: "FF", bitmap: dev->ffbit, FF_MAX);
1159	if (test_bit(EV_SW, dev->evbit))
1160	input_seq_print_bitmap(seq, name: "SW", bitmap: dev->swbit, SW_MAX);
1161
1162	seq_putc(m: seq, c: '\n');
1163
1164	kfree(objp: path);
1165	return 0;
1166	}
1167
1168	static const struct seq_operations input_devices_seq_ops = {
1169	.start = input_devices_seq_start,
1170	.next = input_devices_seq_next,
1171	.stop = input_seq_stop,
1172	.show = input_devices_seq_show,
1173	};
1174
1175	static int input_proc_devices_open(struct inode *inode, struct file *file)
1176	{
1177	return seq_open_private(file, &input_devices_seq_ops,
1178	sizeof(struct input_seq_state));
1179	}
1180
1181	static const struct proc_ops input_devices_proc_ops = {
1182	.proc_open = input_proc_devices_open,
1183	.proc_poll = input_proc_devices_poll,
1184	.proc_read = seq_read,
1185	.proc_lseek = seq_lseek,
1186	.proc_release = seq_release_private,
1187	};
1188
1189	static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1190	{
1191	struct input_seq_state *state = seq->private;
1192	int error;
1193
1194	error = mutex_lock_interruptible(&input_mutex);
1195	if (error) {
1196	state->mutex_acquired = false;
1197	return ERR_PTR(error);
1198	}
1199
1200	state->mutex_acquired = true;
1201	state->pos = *pos;
1202
1203	return seq_list_start(head: &input_handler_list, pos: *pos);
1204	}
1205
1206	static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1207	{
1208	struct input_seq_state *state = seq->private;
1209
1210	state->pos = *pos + 1;
1211	return seq_list_next(v, head: &input_handler_list, ppos: pos);
1212	}
1213
1214	static int input_handlers_seq_show(struct seq_file *seq, void *v)
1215	{
1216	struct input_handler *handler = container_of(v, struct input_handler, node);
1217	struct input_seq_state *state = seq->private;
1218
1219	seq_printf(m: seq, fmt: "N: Number=%u Name=%s", state->pos, handler->name);
1220	if (handler->filter)
1221	seq_puts(m: seq, s: " (filter)");
1222	if (handler->legacy_minors)
1223	seq_printf(m: seq, fmt: " Minor=%d", handler->minor);
1224	seq_putc(m: seq, c: '\n');
1225
1226	return 0;
1227	}
1228
1229	static const struct seq_operations input_handlers_seq_ops = {
1230	.start = input_handlers_seq_start,
1231	.next = input_handlers_seq_next,
1232	.stop = input_seq_stop,
1233	.show = input_handlers_seq_show,
1234	};
1235
1236	static int input_proc_handlers_open(struct inode *inode, struct file *file)
1237	{
1238	return seq_open_private(file, &input_handlers_seq_ops,
1239	sizeof(struct input_seq_state));
1240	}
1241
1242	static const struct proc_ops input_handlers_proc_ops = {
1243	.proc_open = input_proc_handlers_open,
1244	.proc_read = seq_read,
1245	.proc_lseek = seq_lseek,
1246	.proc_release = seq_release_private,
1247	};
1248
1249	static int __init input_proc_init(void)
1250	{
1251	struct proc_dir_entry *entry;
1252
1253	proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1254	if (!proc_bus_input_dir)
1255	return -ENOMEM;
1256
1257	entry = proc_create(name: "devices", mode: 0, parent: proc_bus_input_dir,
1258	proc_ops: &input_devices_proc_ops);
1259	if (!entry)
1260	goto fail1;
1261
1262	entry = proc_create(name: "handlers", mode: 0, parent: proc_bus_input_dir,
1263	proc_ops: &input_handlers_proc_ops);
1264	if (!entry)
1265	goto fail2;
1266
1267	return 0;
1268
1269	fail2: remove_proc_entry("devices", proc_bus_input_dir);
1270	fail1: remove_proc_entry("bus/input", NULL);
1271	return -ENOMEM;
1272	}
1273
1274	static void input_proc_exit(void)
1275	{
1276	remove_proc_entry("devices", proc_bus_input_dir);
1277	remove_proc_entry("handlers", proc_bus_input_dir);
1278	remove_proc_entry("bus/input", NULL);
1279	}
1280
1281	#else /* !CONFIG_PROC_FS */
1282	static inline void input_wakeup_procfs_readers(void) { }
1283	static inline int input_proc_init(void) { return 0; }
1284	static inline void input_proc_exit(void) { }
1285	#endif
1286
1287	#define INPUT_DEV_STRING_ATTR_SHOW(name) \
1288	static ssize_t input_dev_show_##name(struct device *dev, \
1289	struct device_attribute *attr, \
1290	char *buf) \
1291	{ \
1292	struct input_dev *input_dev = to_input_dev(dev); \
1293	\
1294	return sysfs_emit(buf, "%s\n", \
1295	input_dev->name ? input_dev->name : ""); \
1296	} \
1297	static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1298
1299	INPUT_DEV_STRING_ATTR_SHOW(name);
1300	INPUT_DEV_STRING_ATTR_SHOW(phys);
1301	INPUT_DEV_STRING_ATTR_SHOW(uniq);
1302
1303	static int input_print_modalias_bits(char *buf, int size,
1304	char name, const unsigned long *bm,
1305	unsigned int min_bit, unsigned int max_bit)
1306	{
1307	int bit = min_bit;
1308	int len = 0;
1309
1310	len += snprintf(buf, max(size, 0), fmt: "%c", name);
1311	for_each_set_bit_from(bit, bm, max_bit)
1312	len += snprintf(buf: buf + len, max(size - len, 0), fmt: "%X,", bit);
1313	return len;
1314	}
1315
1316	static int input_print_modalias_parts(char *buf, int size, int full_len,
1317	const struct input_dev *id)
1318	{
1319	int len, klen, remainder, space;
1320
1321	len = snprintf(buf, max(size, 0),
1322	fmt: "input:b%04Xv%04Xp%04Xe%04X-",
1323	id->id.bustype, id->id.vendor,
1324	id->id.product, id->id.version);
1325
1326	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1327	name: 'e', bm: id->evbit, min_bit: 0, EV_MAX);
1328
1329	/*
1330	* Calculate the remaining space in the buffer making sure we
1331	* have place for the terminating 0.
1332	*/
1333	space = max(size - (len + 1), 0);
1334
1335	klen = input_print_modalias_bits(buf: buf + len, size: size - len,
1336	name: 'k', bm: id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1337	len += klen;
1338
1339	/*
1340	* If we have more data than we can fit in the buffer, check
1341	* if we can trim key data to fit in the rest. We will indicate
1342	* that key data is incomplete by adding "+" sign at the end, like
1343	* this: * "k1,2,3,45,+,".
1344	*
1345	* Note that we shortest key info (if present) is "k+," so we
1346	* can only try to trim if key data is longer than that.
1347	*/
1348	if (full_len && size < full_len + 1 && klen > 3) {
1349	remainder = full_len - len;
1350	/*
1351	* We can only trim if we have space for the remainder
1352	* and also for at least "k+," which is 3 more characters.
1353	*/
1354	if (remainder <= space - 3) {
1355	/*
1356	* We are guaranteed to have 'k' in the buffer, so
1357	* we need at least 3 additional bytes for storing
1358	* "+," in addition to the remainder.
1359	*/
1360	for (int i = size - 1 - remainder - 3; i >= 0; i--) {
1361	if (buf[i] == 'k' || buf[i] == ',') {
1362	strcpy(p: buf + i + 1, q: "+,");
1363	len = i + 3; /* Not counting '\0' */
1364	break;
1365	}
1366	}
1367	}
1368	}
1369
1370	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1371	name: 'r', bm: id->relbit, min_bit: 0, REL_MAX);
1372	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1373	name: 'a', bm: id->absbit, min_bit: 0, ABS_MAX);
1374	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1375	name: 'm', bm: id->mscbit, min_bit: 0, MSC_MAX);
1376	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1377	name: 'l', bm: id->ledbit, min_bit: 0, LED_MAX);
1378	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1379	name: 's', bm: id->sndbit, min_bit: 0, SND_MAX);
1380	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1381	name: 'f', bm: id->ffbit, min_bit: 0, FF_MAX);
1382	len += input_print_modalias_bits(buf: buf + len, size: size - len,
1383	name: 'w', bm: id->swbit, min_bit: 0, SW_MAX);
1384
1385	return len;
1386	}
1387
1388	static int input_print_modalias(char *buf, int size, const struct input_dev *id)
1389	{
1390	int full_len;
1391
1392	/*
1393	* Printing is done in 2 passes: first one figures out total length
1394	* needed for the modalias string, second one will try to trim key
1395	* data in case when buffer is too small for the entire modalias.
1396	* If the buffer is too small regardless, it will fill as much as it
1397	* can (without trimming key data) into the buffer and leave it to
1398	* the caller to figure out what to do with the result.
1399	*/
1400	full_len = input_print_modalias_parts(NULL, size: 0, full_len: 0, id);
1401	return input_print_modalias_parts(buf, size, full_len, id);
1402	}
1403
1404	static ssize_t input_dev_show_modalias(struct device *dev,
1405	struct device_attribute *attr,
1406	char *buf)
1407	{
1408	struct input_dev *id = to_input_dev(dev);
1409	ssize_t len;
1410
1411	len = input_print_modalias(buf, PAGE_SIZE, id);
1412	if (len < PAGE_SIZE - 2)
1413	len += snprintf(buf: buf + len, PAGE_SIZE - len, fmt: "\n");
1414
1415	return min_t(int, len, PAGE_SIZE);
1416	}
1417	static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1418
1419	static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1420	int max, int add_cr);
1421
1422	static ssize_t input_dev_show_properties(struct device *dev,
1423	struct device_attribute *attr,
1424	char *buf)
1425	{
1426	struct input_dev *input_dev = to_input_dev(dev);
1427	int len = input_print_bitmap(buf, PAGE_SIZE, bitmap: input_dev->propbit,
1428	INPUT_PROP_MAX, add_cr: true);
1429	return min_t(int, len, PAGE_SIZE);
1430	}
1431	static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1432
1433	static int input_inhibit_device(struct input_dev *dev);
1434	static int input_uninhibit_device(struct input_dev *dev);
1435
1436	static ssize_t inhibited_show(struct device *dev,
1437	struct device_attribute *attr,
1438	char *buf)
1439	{
1440	struct input_dev *input_dev = to_input_dev(dev);
1441
1442	return sysfs_emit(buf, fmt: "%d\n", input_dev->inhibited);
1443	}
1444
1445	static ssize_t inhibited_store(struct device *dev,
1446	struct device_attribute *attr, const char *buf,
1447	size_t len)
1448	{
1449	struct input_dev *input_dev = to_input_dev(dev);
1450	ssize_t rv;
1451	bool inhibited;
1452
1453	if (kstrtobool(s: buf, res: &inhibited))
1454	return -EINVAL;
1455
1456	if (inhibited)
1457	rv = input_inhibit_device(dev: input_dev);
1458	else
1459	rv = input_uninhibit_device(dev: input_dev);
1460
1461	if (rv != 0)
1462	return rv;
1463
1464	return len;
1465	}
1466
1467	static DEVICE_ATTR_RW(inhibited);
1468
1469	static struct attribute *input_dev_attrs[] = {
1470	&dev_attr_name.attr,
1471	&dev_attr_phys.attr,
1472	&dev_attr_uniq.attr,
1473	&dev_attr_modalias.attr,
1474	&dev_attr_properties.attr,
1475	&dev_attr_inhibited.attr,
1476	NULL
1477	};
1478
1479	static const struct attribute_group input_dev_attr_group = {
1480	.attrs = input_dev_attrs,
1481	};
1482
1483	#define INPUT_DEV_ID_ATTR(name) \
1484	static ssize_t input_dev_show_id_##name(struct device *dev, \
1485	struct device_attribute *attr, \
1486	char *buf) \
1487	{ \
1488	struct input_dev *input_dev = to_input_dev(dev); \
1489	return sysfs_emit(buf, "%04x\n", input_dev->id.name); \
1490	} \
1491	static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1492
1493	INPUT_DEV_ID_ATTR(bustype);
1494	INPUT_DEV_ID_ATTR(vendor);
1495	INPUT_DEV_ID_ATTR(product);
1496	INPUT_DEV_ID_ATTR(version);
1497
1498	static struct attribute *input_dev_id_attrs[] = {
1499	&dev_attr_bustype.attr,
1500	&dev_attr_vendor.attr,
1501	&dev_attr_product.attr,
1502	&dev_attr_version.attr,
1503	NULL
1504	};
1505
1506	static const struct attribute_group input_dev_id_attr_group = {
1507	.name = "id",
1508	.attrs = input_dev_id_attrs,
1509	};
1510
1511	static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1512	int max, int add_cr)
1513	{
1514	int i;
1515	int len = 0;
1516	bool skip_empty = true;
1517
1518	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1519	len += input_bits_to_string(buf: buf + len, max(buf_size - len, 0),
1520	bits: bitmap[i], skip_empty);
1521	if (len) {
1522	skip_empty = false;
1523	if (i > 0)
1524	len += snprintf(buf: buf + len, max(buf_size - len, 0), fmt: " ");
1525	}
1526	}
1527
1528	/*
1529	* If no output was produced print a single 0.
1530	*/
1531	if (len == 0)
1532	len = snprintf(buf, size: buf_size, fmt: "%d", 0);
1533
1534	if (add_cr)
1535	len += snprintf(buf: buf + len, max(buf_size - len, 0), fmt: "\n");
1536
1537	return len;
1538	}
1539
1540	#define INPUT_DEV_CAP_ATTR(ev, bm) \
1541	static ssize_t input_dev_show_cap_##bm(struct device *dev, \
1542	struct device_attribute *attr, \
1543	char *buf) \
1544	{ \
1545	struct input_dev *input_dev = to_input_dev(dev); \
1546	int len = input_print_bitmap(buf, PAGE_SIZE, \
1547	input_dev->bm##bit, ev##_MAX, \
1548	true); \
1549	return min_t(int, len, PAGE_SIZE); \
1550	} \
1551	static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1552
1553	INPUT_DEV_CAP_ATTR(EV, ev);
1554	INPUT_DEV_CAP_ATTR(KEY, key);
1555	INPUT_DEV_CAP_ATTR(REL, rel);
1556	INPUT_DEV_CAP_ATTR(ABS, abs);
1557	INPUT_DEV_CAP_ATTR(MSC, msc);
1558	INPUT_DEV_CAP_ATTR(LED, led);
1559	INPUT_DEV_CAP_ATTR(SND, snd);
1560	INPUT_DEV_CAP_ATTR(FF, ff);
1561	INPUT_DEV_CAP_ATTR(SW, sw);
1562
1563	static struct attribute *input_dev_caps_attrs[] = {
1564	&dev_attr_ev.attr,
1565	&dev_attr_key.attr,
1566	&dev_attr_rel.attr,
1567	&dev_attr_abs.attr,
1568	&dev_attr_msc.attr,
1569	&dev_attr_led.attr,
1570	&dev_attr_snd.attr,
1571	&dev_attr_ff.attr,
1572	&dev_attr_sw.attr,
1573	NULL
1574	};
1575
1576	static const struct attribute_group input_dev_caps_attr_group = {
1577	.name = "capabilities",
1578	.attrs = input_dev_caps_attrs,
1579	};
1580
1581	static const struct attribute_group *input_dev_attr_groups[] = {
1582	&input_dev_attr_group,
1583	&input_dev_id_attr_group,
1584	&input_dev_caps_attr_group,
1585	&input_poller_attribute_group,
1586	NULL
1587	};
1588
1589	static void input_dev_release(struct device *device)
1590	{
1591	struct input_dev *dev = to_input_dev(device);
1592
1593	input_ff_destroy(dev);
1594	input_mt_destroy_slots(dev);
1595	kfree(objp: dev->poller);
1596	kfree(objp: dev->absinfo);
1597	kfree(objp: dev->vals);
1598	kfree(objp: dev);
1599
1600	module_put(THIS_MODULE);
1601	}
1602
1603	/*
1604	* Input uevent interface - loading event handlers based on
1605	* device bitfields.
1606	*/
1607	static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1608	const char *name, const unsigned long *bitmap, int max)
1609	{
1610	int len;
1611
1612	if (add_uevent_var(env, format: "%s", name))
1613	return -ENOMEM;
1614
1615	len = input_print_bitmap(buf: &env->buf[env->buflen - 1],
1616	buf_size: sizeof(env->buf) - env->buflen,
1617	bitmap, max, add_cr: false);
1618	if (len >= (sizeof(env->buf) - env->buflen))
1619	return -ENOMEM;
1620
1621	env->buflen += len;
1622	return 0;
1623	}
1624
1625	/*
1626	* This is a pretty gross hack. When building uevent data the driver core
1627	* may try adding more environment variables to kobj_uevent_env without
1628	* telling us, so we have no idea how much of the buffer we can use to
1629	* avoid overflows/-ENOMEM elsewhere. To work around this let's artificially
1630	* reduce amount of memory we will use for the modalias environment variable.
1631	*
1632	* The potential additions are:
1633	*
1634	* SEQNUM=18446744073709551615 - (%llu - 28 bytes)
1635	* HOME=/ (6 bytes)
1636	* PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes)
1637	*
1638	* 68 bytes total. Allow extra buffer - 96 bytes
1639	*/
1640	#define UEVENT_ENV_EXTRA_LEN 96
1641
1642	static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1643	const struct input_dev *dev)
1644	{
1645	int len;
1646
1647	if (add_uevent_var(env, format: "MODALIAS="))
1648	return -ENOMEM;
1649
1650	len = input_print_modalias(buf: &env->buf[env->buflen - 1],
1651	size: (int)sizeof(env->buf) - env->buflen -
1652	UEVENT_ENV_EXTRA_LEN,
1653	id: dev);
1654	if (len >= ((int)sizeof(env->buf) - env->buflen -
1655	UEVENT_ENV_EXTRA_LEN))
1656	return -ENOMEM;
1657
1658	env->buflen += len;
1659	return 0;
1660	}
1661
1662	#define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \
1663	do { \
1664	int err = add_uevent_var(env, fmt, val); \
1665	if (err) \
1666	return err; \
1667	} while (0)
1668
1669	#define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \
1670	do { \
1671	int err = input_add_uevent_bm_var(env, name, bm, max); \
1672	if (err) \
1673	return err; \
1674	} while (0)
1675
1676	#define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \
1677	do { \
1678	int err = input_add_uevent_modalias_var(env, dev); \
1679	if (err) \
1680	return err; \
1681	} while (0)
1682
1683	static int input_dev_uevent(const struct device *device, struct kobj_uevent_env *env)
1684	{
1685	const struct input_dev *dev = to_input_dev(device);
1686
1687	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1688	dev->id.bustype, dev->id.vendor,
1689	dev->id.product, dev->id.version);
1690	if (dev->name)
1691	INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1692	if (dev->phys)
1693	INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1694	if (dev->uniq)
1695	INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1696
1697	INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1698
1699	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1700	if (test_bit(EV_KEY, dev->evbit))
1701	INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1702	if (test_bit(EV_REL, dev->evbit))
1703	INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1704	if (test_bit(EV_ABS, dev->evbit))
1705	INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1706	if (test_bit(EV_MSC, dev->evbit))
1707	INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1708	if (test_bit(EV_LED, dev->evbit))
1709	INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1710	if (test_bit(EV_SND, dev->evbit))
1711	INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1712	if (test_bit(EV_FF, dev->evbit))
1713	INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1714	if (test_bit(EV_SW, dev->evbit))
1715	INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1716
1717	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1718
1719	return 0;
1720	}
1721
1722	#define INPUT_DO_TOGGLE(dev, type, bits, on) \
1723	do { \
1724	int i; \
1725	bool active; \
1726	\
1727	if (!test_bit(EV_##type, dev->evbit)) \
1728	break; \
1729	\
1730	for_each_set_bit(i, dev->bits##bit, type##_CNT) { \
1731	active = test_bit(i, dev->bits); \
1732	if (!active && !on) \
1733	continue; \
1734	\
1735	dev->event(dev, EV_##type, i, on ? active : 0); \
1736	} \
1737	} while (0)
1738
1739	static void input_dev_toggle(struct input_dev *dev, bool activate)
1740	{
1741	if (!dev->event)
1742	return;
1743
1744	INPUT_DO_TOGGLE(dev, LED, led, activate);
1745	INPUT_DO_TOGGLE(dev, SND, snd, activate);
1746
1747	if (activate && test_bit(EV_REP, dev->evbit)) {
1748	dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1749	dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1750	}
1751	}
1752
1753	/**
1754	* input_reset_device() - reset/restore the state of input device
1755	* @dev: input device whose state needs to be reset
1756	*
1757	* This function tries to reset the state of an opened input device and
1758	* bring internal state and state if the hardware in sync with each other.
1759	* We mark all keys as released, restore LED state, repeat rate, etc.
1760	*/
1761	void input_reset_device(struct input_dev *dev)
1762	{
1763	guard(mutex)(T: &dev->mutex);
1764	guard(spinlock_irqsave)(l: &dev->event_lock);
1765
1766	input_dev_toggle(dev, activate: true);
1767	if (input_dev_release_keys(dev))
1768	input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
1769	}
1770	EXPORT_SYMBOL(input_reset_device);
1771
1772	static int input_inhibit_device(struct input_dev *dev)
1773	{
1774	guard(mutex)(T: &dev->mutex);
1775
1776	if (dev->inhibited)
1777	return 0;
1778
1779	if (dev->users) {
1780	if (dev->close)
1781	dev->close(dev);
1782	if (dev->poller)
1783	input_dev_poller_stop(poller: dev->poller);
1784	}
1785
1786	scoped_guard(spinlock_irq, &dev->event_lock) {
1787	input_mt_release_slots(dev);
1788	input_dev_release_keys(dev);
1789	input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
1790	input_dev_toggle(dev, activate: false);
1791	}
1792
1793	dev->inhibited = true;
1794
1795	return 0;
1796	}
1797
1798	static int input_uninhibit_device(struct input_dev *dev)
1799	{
1800	int error;
1801
1802	guard(mutex)(T: &dev->mutex);
1803
1804	if (!dev->inhibited)
1805	return 0;
1806
1807	if (dev->users) {
1808	if (dev->open) {
1809	error = dev->open(dev);
1810	if (error)
1811	return error;
1812	}
1813	if (dev->poller)
1814	input_dev_poller_start(poller: dev->poller);
1815	}
1816
1817	dev->inhibited = false;
1818
1819	scoped_guard(spinlock_irq, &dev->event_lock)
1820	input_dev_toggle(dev, activate: true);
1821
1822	return 0;
1823	}
1824
1825	static int input_dev_suspend(struct device *dev)
1826	{
1827	struct input_dev *input_dev = to_input_dev(dev);
1828
1829	guard(spinlock_irq)(l: &input_dev->event_lock);
1830
1831	/*
1832	* Keys that are pressed now are unlikely to be
1833	* still pressed when we resume.
1834	*/
1835	if (input_dev_release_keys(dev: input_dev))
1836	input_handle_event(dev: input_dev, EV_SYN, SYN_REPORT, value: 1);
1837
1838	/* Turn off LEDs and sounds, if any are active. */
1839	input_dev_toggle(dev: input_dev, activate: false);
1840
1841	return 0;
1842	}
1843
1844	static int input_dev_resume(struct device *dev)
1845	{
1846	struct input_dev *input_dev = to_input_dev(dev);
1847
1848	guard(spinlock_irq)(l: &input_dev->event_lock);
1849
1850	/* Restore state of LEDs and sounds, if any were active. */
1851	input_dev_toggle(dev: input_dev, activate: true);
1852
1853	return 0;
1854	}
1855
1856	static int input_dev_freeze(struct device *dev)
1857	{
1858	struct input_dev *input_dev = to_input_dev(dev);
1859
1860	guard(spinlock_irq)(l: &input_dev->event_lock);
1861
1862	/*
1863	* Keys that are pressed now are unlikely to be
1864	* still pressed when we resume.
1865	*/
1866	if (input_dev_release_keys(dev: input_dev))
1867	input_handle_event(dev: input_dev, EV_SYN, SYN_REPORT, value: 1);
1868
1869	return 0;
1870	}
1871
1872	static int input_dev_poweroff(struct device *dev)
1873	{
1874	struct input_dev *input_dev = to_input_dev(dev);
1875
1876	guard(spinlock_irq)(l: &input_dev->event_lock);
1877
1878	/* Turn off LEDs and sounds, if any are active. */
1879	input_dev_toggle(dev: input_dev, activate: false);
1880
1881	return 0;
1882	}
1883
1884	static const struct dev_pm_ops input_dev_pm_ops = {
1885	.suspend = input_dev_suspend,
1886	.resume = input_dev_resume,
1887	.freeze = input_dev_freeze,
1888	.poweroff = input_dev_poweroff,
1889	.restore = input_dev_resume,
1890	};
1891
1892	static const struct device_type input_dev_type = {
1893	.groups = input_dev_attr_groups,
1894	.release = input_dev_release,
1895	.uevent = input_dev_uevent,
1896	.pm = pm_sleep_ptr(&input_dev_pm_ops),
1897	};
1898
1899	static char *input_devnode(const struct device *dev, umode_t *mode)
1900	{
1901	return kasprintf(GFP_KERNEL, fmt: "input/%s", dev_name(dev));
1902	}
1903
1904	const struct class input_class = {
1905	.name = "input",
1906	.devnode = input_devnode,
1907	};
1908	EXPORT_SYMBOL_GPL(input_class);
1909
1910	/**
1911	* input_allocate_device - allocate memory for new input device
1912	*
1913	* Returns prepared struct input_dev or %NULL.
1914	*
1915	* NOTE: Use input_free_device() to free devices that have not been
1916	* registered; input_unregister_device() should be used for already
1917	* registered devices.
1918	*/
1919	struct input_dev *input_allocate_device(void)
1920	{
1921	static atomic_t input_no = ATOMIC_INIT(-1);
1922	struct input_dev *dev;
1923
1924	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1925	if (!dev)
1926	return NULL;
1927
1928	/*
1929	* Start with space for SYN_REPORT + 7 EV_KEY/EV_MSC events + 2 spare,
1930	* see input_estimate_events_per_packet(). We will tune the number
1931	* when we register the device.
1932	*/
1933	dev->max_vals = 10;
1934	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
1935	if (!dev->vals) {
1936	kfree(objp: dev);
1937	return NULL;
1938	}
1939
1940	mutex_init(&dev->mutex);
1941	spin_lock_init(&dev->event_lock);
1942	timer_setup(&dev->timer, NULL, 0);
1943	INIT_LIST_HEAD(list: &dev->h_list);
1944	INIT_LIST_HEAD(list: &dev->node);
1945
1946	dev->dev.type = &input_dev_type;
1947	dev->dev.class = &input_class;
1948	device_initialize(dev: &dev->dev);
1949	/*
1950	* From this point on we can no longer simply "kfree(dev)", we need
1951	* to use input_free_device() so that device core properly frees its
1952	* resources associated with the input device.
1953	*/
1954
1955	dev_set_name(dev: &dev->dev, name: "input%lu",
1956	(unsigned long)atomic_inc_return(v: &input_no));
1957
1958	__module_get(THIS_MODULE);
1959
1960	return dev;
1961	}
1962	EXPORT_SYMBOL(input_allocate_device);
1963
1964	struct input_devres {
1965	struct input_dev *input;
1966	};
1967
1968	static int devm_input_device_match(struct device *dev, void *res, void *data)
1969	{
1970	struct input_devres *devres = res;
1971
1972	return devres->input == data;
1973	}
1974
1975	static void devm_input_device_release(struct device *dev, void *res)
1976	{
1977	struct input_devres *devres = res;
1978	struct input_dev *input = devres->input;
1979
1980	dev_dbg(dev, "%s: dropping reference to %s\n",
1981	__func__, dev_name(&input->dev));
1982	input_put_device(dev: input);
1983	}
1984
1985	/**
1986	* devm_input_allocate_device - allocate managed input device
1987	* @dev: device owning the input device being created
1988	*
1989	* Returns prepared struct input_dev or %NULL.
1990	*
1991	* Managed input devices do not need to be explicitly unregistered or
1992	* freed as it will be done automatically when owner device unbinds from
1993	* its driver (or binding fails). Once managed input device is allocated,
1994	* it is ready to be set up and registered in the same fashion as regular
1995	* input device. There are no special devm_input_device_[un]register()
1996	* variants, regular ones work with both managed and unmanaged devices,
1997	* should you need them. In most cases however, managed input device need
1998	* not be explicitly unregistered or freed.
1999	*
2000	* NOTE: the owner device is set up as parent of input device and users
2001	* should not override it.
2002	*/
2003	struct input_dev *devm_input_allocate_device(struct device *dev)
2004	{
2005	struct input_dev *input;
2006	struct input_devres *devres;
2007
2008	devres = devres_alloc(devm_input_device_release,
2009	sizeof(*devres), GFP_KERNEL);
2010	if (!devres)
2011	return NULL;
2012
2013	input = input_allocate_device();
2014	if (!input) {
2015	devres_free(res: devres);
2016	return NULL;
2017	}
2018
2019	input->dev.parent = dev;
2020	input->devres_managed = true;
2021
2022	devres->input = input;
2023	devres_add(dev, res: devres);
2024
2025	return input;
2026	}
2027	EXPORT_SYMBOL(devm_input_allocate_device);
2028
2029	/**
2030	* input_free_device - free memory occupied by input_dev structure
2031	* @dev: input device to free
2032	*
2033	* This function should only be used if input_register_device()
2034	* was not called yet or if it failed. Once device was registered
2035	* use input_unregister_device() and memory will be freed once last
2036	* reference to the device is dropped.
2037	*
2038	* Device should be allocated by input_allocate_device().
2039	*
2040	* NOTE: If there are references to the input device then memory
2041	* will not be freed until last reference is dropped.
2042	*/
2043	void input_free_device(struct input_dev *dev)
2044	{
2045	if (dev) {
2046	if (dev->devres_managed)
2047	WARN_ON(devres_destroy(dev->dev.parent,
2048	devm_input_device_release,
2049	devm_input_device_match,
2050	dev));
2051	input_put_device(dev);
2052	}
2053	}
2054	EXPORT_SYMBOL(input_free_device);
2055
2056	/**
2057	* input_set_timestamp - set timestamp for input events
2058	* @dev: input device to set timestamp for
2059	* @timestamp: the time at which the event has occurred
2060	* in CLOCK_MONOTONIC
2061	*
2062	* This function is intended to provide to the input system a more
2063	* accurate time of when an event actually occurred. The driver should
2064	* call this function as soon as a timestamp is acquired ensuring
2065	* clock conversions in input_set_timestamp are done correctly.
2066	*
2067	* The system entering suspend state between timestamp acquisition and
2068	* calling input_set_timestamp can result in inaccurate conversions.
2069	*/
2070	void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
2071	{
2072	dev->timestamp[INPUT_CLK_MONO] = timestamp;
2073	dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(mono: timestamp);
2074	dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(tmono: timestamp,
2075	offs: TK_OFFS_BOOT);
2076	}
2077	EXPORT_SYMBOL(input_set_timestamp);
2078
2079	/**
2080	* input_get_timestamp - get timestamp for input events
2081	* @dev: input device to get timestamp from
2082	*
2083	* A valid timestamp is a timestamp of non-zero value.
2084	*/
2085	ktime_t *input_get_timestamp(struct input_dev *dev)
2086	{
2087	const ktime_t invalid_timestamp = ktime_set(secs: 0, nsecs: 0);
2088
2089	if (!ktime_compare(cmp1: dev->timestamp[INPUT_CLK_MONO], cmp2: invalid_timestamp))
2090	input_set_timestamp(dev, ktime_get());
2091
2092	return dev->timestamp;
2093	}
2094	EXPORT_SYMBOL(input_get_timestamp);
2095
2096	/**
2097	* input_set_capability - mark device as capable of a certain event
2098	* @dev: device that is capable of emitting or accepting event
2099	* @type: type of the event (EV_KEY, EV_REL, etc...)
2100	* @code: event code
2101	*
2102	* In addition to setting up corresponding bit in appropriate capability
2103	* bitmap the function also adjusts dev->evbit.
2104	*/
2105	void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
2106	{
2107	if (type < EV_CNT && input_max_code[type] &&
2108	code > input_max_code[type]) {
2109	pr_err("%s: invalid code %u for type %u\n", __func__, code,
2110	type);
2111	dump_stack();
2112	return;
2113	}
2114
2115	switch (type) {
2116	case EV_KEY:
2117	__set_bit(code, dev->keybit);
2118	break;
2119
2120	case EV_REL:
2121	__set_bit(code, dev->relbit);
2122	break;
2123
2124	case EV_ABS:
2125	input_alloc_absinfo(dev);
2126	__set_bit(code, dev->absbit);
2127	break;
2128
2129	case EV_MSC:
2130	__set_bit(code, dev->mscbit);
2131	break;
2132
2133	case EV_SW:
2134	__set_bit(code, dev->swbit);
2135	break;
2136
2137	case EV_LED:
2138	__set_bit(code, dev->ledbit);
2139	break;
2140
2141	case EV_SND:
2142	__set_bit(code, dev->sndbit);
2143	break;
2144
2145	case EV_FF:
2146	__set_bit(code, dev->ffbit);
2147	break;
2148
2149	case EV_PWR:
2150	/* do nothing */
2151	break;
2152
2153	default:
2154	pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2155	dump_stack();
2156	return;
2157	}
2158
2159	__set_bit(type, dev->evbit);
2160	}
2161	EXPORT_SYMBOL(input_set_capability);
2162
2163	static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2164	{
2165	int mt_slots;
2166	int i;
2167	unsigned int events;
2168
2169	if (dev->mt) {
2170	mt_slots = dev->mt->num_slots;
2171	} else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2172	mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2173	dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1;
2174	mt_slots = clamp(mt_slots, 2, 32);
2175	} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2176	mt_slots = 2;
2177	} else {
2178	mt_slots = 0;
2179	}
2180
2181	events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2182
2183	if (test_bit(EV_ABS, dev->evbit))
2184	for_each_set_bit(i, dev->absbit, ABS_CNT)
2185	events += input_is_mt_axis(axis: i) ? mt_slots : 1;
2186
2187	if (test_bit(EV_REL, dev->evbit))
2188	events += bitmap_weight(src: dev->relbit, REL_CNT);
2189
2190	/* Make room for KEY and MSC events */
2191	events += 7;
2192
2193	return events;
2194	}
2195
2196	#define INPUT_CLEANSE_BITMASK(dev, type, bits) \
2197	do { \
2198	if (!test_bit(EV_##type, dev->evbit)) \
2199	memset(dev->bits##bit, 0, \
2200	sizeof(dev->bits##bit)); \
2201	} while (0)
2202
2203	static void input_cleanse_bitmasks(struct input_dev *dev)
2204	{
2205	INPUT_CLEANSE_BITMASK(dev, KEY, key);
2206	INPUT_CLEANSE_BITMASK(dev, REL, rel);
2207	INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2208	INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2209	INPUT_CLEANSE_BITMASK(dev, LED, led);
2210	INPUT_CLEANSE_BITMASK(dev, SND, snd);
2211	INPUT_CLEANSE_BITMASK(dev, FF, ff);
2212	INPUT_CLEANSE_BITMASK(dev, SW, sw);
2213	}
2214
2215	static void __input_unregister_device(struct input_dev *dev)
2216	{
2217	struct input_handle *handle, *next;
2218
2219	input_disconnect_device(dev);
2220
2221	scoped_guard(mutex, &input_mutex) {
2222	list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2223	handle->handler->disconnect(handle);
2224	WARN_ON(!list_empty(&dev->h_list));
2225
2226	timer_delete_sync(timer: &dev->timer);
2227	list_del_init(entry: &dev->node);
2228
2229	input_wakeup_procfs_readers();
2230	}
2231
2232	device_del(dev: &dev->dev);
2233	}
2234
2235	static void devm_input_device_unregister(struct device *dev, void *res)
2236	{
2237	struct input_devres *devres = res;
2238	struct input_dev *input = devres->input;
2239
2240	dev_dbg(dev, "%s: unregistering device %s\n",
2241	__func__, dev_name(&input->dev));
2242	__input_unregister_device(dev: input);
2243	}
2244
2245	/*
2246	* Generate software autorepeat event. Note that we take
2247	* dev->event_lock here to avoid racing with input_event
2248	* which may cause keys get "stuck".
2249	*/
2250	static void input_repeat_key(struct timer_list *t)
2251	{
2252	struct input_dev *dev = timer_container_of(dev, t, timer);
2253
2254	guard(spinlock_irqsave)(l: &dev->event_lock);
2255
2256	if (!dev->inhibited &&
2257	test_bit(dev->repeat_key, dev->key) &&
2258	is_event_supported(code: dev->repeat_key, bm: dev->keybit, KEY_MAX)) {
2259
2260	input_set_timestamp(dev, ktime_get());
2261	input_handle_event(dev, EV_KEY, code: dev->repeat_key, value: 2);
2262	input_handle_event(dev, EV_SYN, SYN_REPORT, value: 1);
2263
2264	if (dev->rep[REP_PERIOD])
2265	mod_timer(timer: &dev->timer, expires: jiffies +
2266	msecs_to_jiffies(m: dev->rep[REP_PERIOD]));
2267	}
2268	}
2269
2270	/**
2271	* input_enable_softrepeat - enable software autorepeat
2272	* @dev: input device
2273	* @delay: repeat delay
2274	* @period: repeat period
2275	*
2276	* Enable software autorepeat on the input device.
2277	*/
2278	void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2279	{
2280	dev->timer.function = input_repeat_key;
2281	dev->rep[REP_DELAY] = delay;
2282	dev->rep[REP_PERIOD] = period;
2283	}
2284	EXPORT_SYMBOL(input_enable_softrepeat);
2285
2286	bool input_device_enabled(struct input_dev *dev)
2287	{
2288	lockdep_assert_held(&dev->mutex);
2289
2290	return !dev->inhibited && dev->users > 0;
2291	}
2292	EXPORT_SYMBOL_GPL(input_device_enabled);
2293
2294	static int input_device_tune_vals(struct input_dev *dev)
2295	{
2296	struct input_value *vals;
2297	unsigned int packet_size;
2298	unsigned int max_vals;
2299
2300	packet_size = input_estimate_events_per_packet(dev);
2301	if (dev->hint_events_per_packet < packet_size)
2302	dev->hint_events_per_packet = packet_size;
2303
2304	max_vals = dev->hint_events_per_packet + 2;
2305	if (dev->max_vals >= max_vals)
2306	return 0;
2307
2308	vals = kcalloc(max_vals, sizeof(*vals), GFP_KERNEL);
2309	if (!vals)
2310	return -ENOMEM;
2311
2312	scoped_guard(spinlock_irq, &dev->event_lock) {
2313	dev->max_vals = max_vals;
2314	swap(dev->vals, vals);
2315	}
2316
2317	/* Because of swap() above, this frees the old vals memory */
2318	kfree(objp: vals);
2319
2320	return 0;
2321	}
2322
2323	/**
2324	* input_register_device - register device with input core
2325	* @dev: device to be registered
2326	*
2327	* This function registers device with input core. The device must be
2328	* allocated with input_allocate_device() and all it's capabilities
2329	* set up before registering.
2330	* If function fails the device must be freed with input_free_device().
2331	* Once device has been successfully registered it can be unregistered
2332	* with input_unregister_device(); input_free_device() should not be
2333	* called in this case.
2334	*
2335	* Note that this function is also used to register managed input devices
2336	* (ones allocated with devm_input_allocate_device()). Such managed input
2337	* devices need not be explicitly unregistered or freed, their tear down
2338	* is controlled by the devres infrastructure. It is also worth noting
2339	* that tear down of managed input devices is internally a 2-step process:
2340	* registered managed input device is first unregistered, but stays in
2341	* memory and can still handle input_event() calls (although events will
2342	* not be delivered anywhere). The freeing of managed input device will
2343	* happen later, when devres stack is unwound to the point where device
2344	* allocation was made.
2345	*/
2346	int input_register_device(struct input_dev *dev)
2347	{
2348	struct input_devres *devres = NULL;
2349	struct input_handler *handler;
2350	const char *path;
2351	int error;
2352
2353	if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2354	dev_err(&dev->dev,
2355	"Absolute device without dev->absinfo, refusing to register\n");
2356	return -EINVAL;
2357	}
2358
2359	if (dev->devres_managed) {
2360	devres = devres_alloc(devm_input_device_unregister,
2361	sizeof(*devres), GFP_KERNEL);
2362	if (!devres)
2363	return -ENOMEM;
2364
2365	devres->input = dev;
2366	}
2367
2368	/* Every input device generates EV_SYN/SYN_REPORT events. */
2369	__set_bit(EV_SYN, dev->evbit);
2370
2371	/* KEY_RESERVED is not supposed to be transmitted to userspace. */
2372	__clear_bit(KEY_RESERVED, dev->keybit);
2373
2374	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2375	input_cleanse_bitmasks(dev);
2376
2377	error = input_device_tune_vals(dev);
2378	if (error)
2379	goto err_devres_free;
2380
2381	/*
2382	* If delay and period are pre-set by the driver, then autorepeating
2383	* is handled by the driver itself and we don't do it in input.c.
2384	*/
2385	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2386	input_enable_softrepeat(dev, 250, 33);
2387
2388	if (!dev->getkeycode)
2389	dev->getkeycode = input_default_getkeycode;
2390
2391	if (!dev->setkeycode)
2392	dev->setkeycode = input_default_setkeycode;
2393
2394	if (dev->poller)
2395	input_dev_poller_finalize(poller: dev->poller);
2396
2397	error = device_add(dev: &dev->dev);
2398	if (error)
2399	goto err_devres_free;
2400
2401	path = kobject_get_path(kobj: &dev->dev.kobj, GFP_KERNEL);
2402	pr_info("%s as %s\n",
2403	dev->name ? dev->name : "Unspecified device",
2404	path ? path : "N/A");
2405	kfree(objp: path);
2406
2407	error = -EINTR;
2408	scoped_cond_guard(mutex_intr, goto err_device_del, &input_mutex) {
2409	list_add_tail(new: &dev->node, head: &input_dev_list);
2410
2411	list_for_each_entry(handler, &input_handler_list, node)
2412	input_attach_handler(dev, handler);
2413
2414	input_wakeup_procfs_readers();
2415	}
2416
2417	if (dev->devres_managed) {
2418	dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2419	__func__, dev_name(&dev->dev));
2420	devres_add(dev: dev->dev.parent, res: devres);
2421	}
2422	return 0;
2423
2424	err_device_del:
2425	device_del(dev: &dev->dev);
2426	err_devres_free:
2427	devres_free(res: devres);
2428	return error;
2429	}
2430	EXPORT_SYMBOL(input_register_device);
2431
2432	/**
2433	* input_unregister_device - unregister previously registered device
2434	* @dev: device to be unregistered
2435	*
2436	* This function unregisters an input device. Once device is unregistered
2437	* the caller should not try to access it as it may get freed at any moment.
2438	*/
2439	void input_unregister_device(struct input_dev *dev)
2440	{
2441	if (dev->devres_managed) {
2442	WARN_ON(devres_destroy(dev->dev.parent,
2443	devm_input_device_unregister,
2444	devm_input_device_match,
2445	dev));
2446	__input_unregister_device(dev);
2447	/*
2448	* We do not do input_put_device() here because it will be done
2449	* when 2nd devres fires up.
2450	*/
2451	} else {
2452	__input_unregister_device(dev);
2453	input_put_device(dev);
2454	}
2455	}
2456	EXPORT_SYMBOL(input_unregister_device);
2457
2458	static int input_handler_check_methods(const struct input_handler *handler)
2459	{
2460	int count = 0;
2461
2462	if (handler->filter)
2463	count++;
2464	if (handler->events)
2465	count++;
2466	if (handler->event)
2467	count++;
2468
2469	if (count > 1) {
2470	pr_err("%s: only one event processing method can be defined (%s)\n",
2471	__func__, handler->name);
2472	return -EINVAL;
2473	}
2474
2475	return 0;
2476	}
2477
2478	/**
2479	* input_register_handler - register a new input handler
2480	* @handler: handler to be registered
2481	*
2482	* This function registers a new input handler (interface) for input
2483	* devices in the system and attaches it to all input devices that
2484	* are compatible with the handler.
2485	*/
2486	int input_register_handler(struct input_handler *handler)
2487	{
2488	struct input_dev *dev;
2489	int error;
2490
2491	error = input_handler_check_methods(handler);
2492	if (error)
2493	return error;
2494
2495	scoped_cond_guard(mutex_intr, return -EINTR, &input_mutex) {
2496	INIT_LIST_HEAD(list: &handler->h_list);
2497
2498	list_add_tail(new: &handler->node, head: &input_handler_list);
2499
2500	list_for_each_entry(dev, &input_dev_list, node)
2501	input_attach_handler(dev, handler);
2502
2503	input_wakeup_procfs_readers();
2504	}
2505
2506	return 0;
2507	}
2508	EXPORT_SYMBOL(input_register_handler);
2509
2510	/**
2511	* input_unregister_handler - unregisters an input handler
2512	* @handler: handler to be unregistered
2513	*
2514	* This function disconnects a handler from its input devices and
2515	* removes it from lists of known handlers.
2516	*/
2517	void input_unregister_handler(struct input_handler *handler)
2518	{
2519	struct input_handle *handle, *next;
2520
2521	guard(mutex)(T: &input_mutex);
2522
2523	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2524	handler->disconnect(handle);
2525	WARN_ON(!list_empty(&handler->h_list));
2526
2527	list_del_init(entry: &handler->node);
2528
2529	input_wakeup_procfs_readers();
2530	}
2531	EXPORT_SYMBOL(input_unregister_handler);
2532
2533	/**
2534	* input_handler_for_each_handle - handle iterator
2535	* @handler: input handler to iterate
2536	* @data: data for the callback
2537	* @fn: function to be called for each handle
2538	*
2539	* Iterate over @bus's list of devices, and call @fn for each, passing
2540	* it @data and stop when @fn returns a non-zero value. The function is
2541	* using RCU to traverse the list and therefore may be using in atomic
2542	* contexts. The @fn callback is invoked from RCU critical section and
2543	* thus must not sleep.
2544	*/
2545	int input_handler_for_each_handle(struct input_handler *handler, void *data,
2546	int (*fn)(struct input_handle *, void *))
2547	{
2548	struct input_handle *handle;
2549	int retval;
2550
2551	guard(rcu)();
2552
2553	list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2554	retval = fn(handle, data);
2555	if (retval)
2556	return retval;
2557	}
2558
2559	return 0;
2560	}
2561	EXPORT_SYMBOL(input_handler_for_each_handle);
2562
2563	/*
2564	* An implementation of input_handle's handle_events() method that simply
2565	* invokes handler->event() method for each event one by one.
2566	*/
2567	static unsigned int input_handle_events_default(struct input_handle *handle,
2568	struct input_value *vals,
2569	unsigned int count)
2570	{
2571	struct input_handler *handler = handle->handler;
2572	struct input_value *v;
2573
2574	for (v = vals; v != vals + count; v++)
2575	handler->event(handle, v->type, v->code, v->value);
2576
2577	return count;
2578	}
2579
2580	/*
2581	* An implementation of input_handle's handle_events() method that invokes
2582	* handler->filter() method for each event one by one and removes events
2583	* that were filtered out from the "vals" array.
2584	*/
2585	static unsigned int input_handle_events_filter(struct input_handle *handle,
2586	struct input_value *vals,
2587	unsigned int count)
2588	{
2589	struct input_handler *handler = handle->handler;
2590	struct input_value *end = vals;
2591	struct input_value *v;
2592
2593	for (v = vals; v != vals + count; v++) {
2594	if (handler->filter(handle, v->type, v->code, v->value))
2595	continue;
2596	if (end != v)
2597	*end = *v;
2598	end++;
2599	}
2600
2601	return end - vals;
2602	}
2603
2604	/*
2605	* An implementation of input_handle's handle_events() method that does nothing.
2606	*/
2607	static unsigned int input_handle_events_null(struct input_handle *handle,
2608	struct input_value *vals,
2609	unsigned int count)
2610	{
2611	return count;
2612	}
2613
2614	/*
2615	* Sets up appropriate handle->event_handler based on the input_handler
2616	* associated with the handle.
2617	*/
2618	static void input_handle_setup_event_handler(struct input_handle *handle)
2619	{
2620	struct input_handler *handler = handle->handler;
2621
2622	if (handler->filter)
2623	handle->handle_events = input_handle_events_filter;
2624	else if (handler->event)
2625	handle->handle_events = input_handle_events_default;
2626	else if (handler->events)
2627	handle->handle_events = handler->events;
2628	else
2629	handle->handle_events = input_handle_events_null;
2630	}
2631
2632	/**
2633	* input_register_handle - register a new input handle
2634	* @handle: handle to register
2635	*
2636	* This function puts a new input handle onto device's
2637	* and handler's lists so that events can flow through
2638	* it once it is opened using input_open_device().
2639	*
2640	* This function is supposed to be called from handler's
2641	* connect() method.
2642	*/
2643	int input_register_handle(struct input_handle *handle)
2644	{
2645	struct input_handler *handler = handle->handler;
2646	struct input_dev *dev = handle->dev;
2647
2648	input_handle_setup_event_handler(handle);
2649	/*
2650	* We take dev->mutex here to prevent race with
2651	* input_release_device().
2652	*/
2653	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
2654	/*
2655	* Filters go to the head of the list, normal handlers
2656	* to the tail.
2657	*/
2658	if (handler->filter)
2659	list_add_rcu(new: &handle->d_node, head: &dev->h_list);
2660	else
2661	list_add_tail_rcu(new: &handle->d_node, head: &dev->h_list);
2662	}
2663
2664	/*
2665	* Since we are supposed to be called from ->connect()
2666	* which is mutually exclusive with ->disconnect()
2667	* we can't be racing with input_unregister_handle()
2668	* and so separate lock is not needed here.
2669	*/
2670	list_add_tail_rcu(new: &handle->h_node, head: &handler->h_list);
2671
2672	if (handler->start)
2673	handler->start(handle);
2674
2675	return 0;
2676	}
2677	EXPORT_SYMBOL(input_register_handle);
2678
2679	/**
2680	* input_unregister_handle - unregister an input handle
2681	* @handle: handle to unregister
2682	*
2683	* This function removes input handle from device's
2684	* and handler's lists.
2685	*
2686	* This function is supposed to be called from handler's
2687	* disconnect() method.
2688	*/
2689	void input_unregister_handle(struct input_handle *handle)
2690	{
2691	struct input_dev *dev = handle->dev;
2692
2693	list_del_rcu(entry: &handle->h_node);
2694
2695	/*
2696	* Take dev->mutex to prevent race with input_release_device().
2697	*/
2698	scoped_guard(mutex, &dev->mutex)
2699	list_del_rcu(entry: &handle->d_node);
2700
2701	synchronize_rcu();
2702	}
2703	EXPORT_SYMBOL(input_unregister_handle);
2704
2705	/**
2706	* input_get_new_minor - allocates a new input minor number
2707	* @legacy_base: beginning or the legacy range to be searched
2708	* @legacy_num: size of legacy range
2709	* @allow_dynamic: whether we can also take ID from the dynamic range
2710	*
2711	* This function allocates a new device minor for from input major namespace.
2712	* Caller can request legacy minor by specifying @legacy_base and @legacy_num
2713	* parameters and whether ID can be allocated from dynamic range if there are
2714	* no free IDs in legacy range.
2715	*/
2716	int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2717	bool allow_dynamic)
2718	{
2719	/*
2720	* This function should be called from input handler's ->connect()
2721	* methods, which are serialized with input_mutex, so no additional
2722	* locking is needed here.
2723	*/
2724	if (legacy_base >= 0) {
2725	int minor = ida_alloc_range(&input_ida, min: legacy_base,
2726	max: legacy_base + legacy_num - 1,
2727	GFP_KERNEL);
2728	if (minor >= 0 || !allow_dynamic)
2729	return minor;
2730	}
2731
2732	return ida_alloc_range(&input_ida, INPUT_FIRST_DYNAMIC_DEV,
2733	INPUT_MAX_CHAR_DEVICES - 1, GFP_KERNEL);
2734	}
2735	EXPORT_SYMBOL(input_get_new_minor);
2736
2737	/**
2738	* input_free_minor - release previously allocated minor
2739	* @minor: minor to be released
2740	*
2741	* This function releases previously allocated input minor so that it can be
2742	* reused later.
2743	*/
2744	void input_free_minor(unsigned int minor)
2745	{
2746	ida_free(&input_ida, id: minor);
2747	}
2748	EXPORT_SYMBOL(input_free_minor);
2749
2750	static int __init input_init(void)
2751	{
2752	int err;
2753
2754	err = class_register(class: &input_class);
2755	if (err) {
2756	pr_err("unable to register input_dev class\n");
2757	return err;
2758	}
2759
2760	err = input_proc_init();
2761	if (err)
2762	goto fail1;
2763
2764	err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2765	INPUT_MAX_CHAR_DEVICES, "input");
2766	if (err) {
2767	pr_err("unable to register char major %d", INPUT_MAJOR);
2768	goto fail2;
2769	}
2770
2771	return 0;
2772
2773	fail2: input_proc_exit();
2774	fail1: class_unregister(class: &input_class);
2775	return err;
2776	}
2777
2778	static void __exit input_exit(void)
2779	{
2780	input_proc_exit();
2781	unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2782	INPUT_MAX_CHAR_DEVICES);
2783	class_unregister(class: &input_class);
2784	}
2785
2786	subsys_initcall(input_init);
2787	module_exit(input_exit);
2788