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