1 /*
2 * The input core
3 *
4 * Copyright (c) 1999-2002 Vojtech Pavlik
5 */
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 */
13 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
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"
32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
33 MODULE_DESCRIPTION("Input core");
34 MODULE_LICENSE("GPL");
36 #define INPUT_MAX_CHAR_DEVICES 1024
37 #define INPUT_FIRST_DYNAMIC_DEV 256
38 static DEFINE_IDA(input_ida);
40 static LIST_HEAD(input_dev_list);
41 static LIST_HEAD(input_handler_list);
43 /*
44 * input_mutex protects access to both input_dev_list and input_handler_list.
45 * This also causes input_[un]register_device and input_[un]register_handler
46 * be mutually exclusive which simplifies locking in drivers implementing
47 * input handlers.
48 */
49 static DEFINE_MUTEX(input_mutex);
51 static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
53 static 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 }
59 static 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;
65 if (value > old_val - fuzz && value < old_val + fuzz)
66 return (old_val * 3 + value) / 4;
68 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
69 return (old_val + value) / 2;
70 }
72 return value;
73 }
75 static 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 }
86 static void input_stop_autorepeat(struct input_dev *dev)
87 {
88 del_timer(&dev->timer);
89 }
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 */
96 static 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;
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 }
112 count = end - vals;
113 if (!count)
114 return 0;
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);
122 return count;
123 }
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 */
130 static 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;
136 if (!count)
137 return;
139 rcu_read_lock();
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 }
150 rcu_read_unlock();
152 add_input_randomness(vals->type, vals->code, vals->value);
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 }
165 static 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 } };
170 input_pass_values(dev, vals, ARRAY_SIZE(vals));
171 }
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 */
178 static void input_repeat_key(unsigned long data)
179 {
180 struct input_dev *dev = (void *) data;
181 unsigned long flags;
183 spin_lock_irqsave(&dev->event_lock, flags);
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 };
192 input_pass_values(dev, vals, ARRAY_SIZE(vals));
194 if (dev->rep[REP_PERIOD])
195 mod_timer(&dev->timer, jiffies +
196 msecs_to_jiffies(dev->rep[REP_PERIOD]));
197 }
199 spin_unlock_irqrestore(&dev->event_lock, flags);
200 }
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)
209 static 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;
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;
224 return INPUT_IGNORE_EVENT;
225 }
227 is_mt_event = input_is_mt_value(code);
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 }
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;
247 *pold = *pval;
248 }
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 }
256 return INPUT_PASS_TO_HANDLERS;
257 }
259 static int input_get_disposition(struct input_dev *dev,
260 unsigned int type, unsigned int code, int value)
261 {
262 int disposition = INPUT_IGNORE_EVENT;
264 switch (type) {
266 case EV_SYN:
267 switch (code) {
268 case SYN_CONFIG:
269 disposition = INPUT_PASS_TO_ALL;
270 break;
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;
281 case EV_KEY:
282 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
284 /* auto-repeat bypasses state updates */
285 if (value == 2) {
286 disposition = INPUT_PASS_TO_HANDLERS;
287 break;
288 }
290 if (!!test_bit(code, dev->key) != !!value) {
292 __change_bit(code, dev->key);
293 disposition = INPUT_PASS_TO_HANDLERS;
294 }
295 }
296 break;
298 case EV_SW:
299 if (is_event_supported(code, dev->swbit, SW_MAX) &&
300 !!test_bit(code, dev->sw) != !!value) {
302 __change_bit(code, dev->sw);
303 disposition = INPUT_PASS_TO_HANDLERS;
304 }
305 break;
307 case EV_ABS:
308 if (is_event_supported(code, dev->absbit, ABS_MAX))
309 disposition = input_handle_abs_event(dev, code, &value);
311 break;
313 case EV_REL:
314 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
315 disposition = INPUT_PASS_TO_HANDLERS;
317 break;
319 case EV_MSC:
320 if (is_event_supported(code, dev->mscbit, MSC_MAX))
321 disposition = INPUT_PASS_TO_ALL;
323 break;
325 case EV_LED:
326 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
327 !!test_bit(code, dev->led) != !!value) {
329 __change_bit(code, dev->led);
330 disposition = INPUT_PASS_TO_ALL;
331 }
332 break;
334 case EV_SND:
335 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
337 if (!!test_bit(code, dev->snd) != !!value)
338 __change_bit(code, dev->snd);
339 disposition = INPUT_PASS_TO_ALL;
340 }
341 break;
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;
350 case EV_FF:
351 if (value >= 0)
352 disposition = INPUT_PASS_TO_ALL;
353 break;
355 case EV_PWR:
356 disposition = INPUT_PASS_TO_ALL;
357 break;
358 }
360 return disposition;
361 }
363 static void input_handle_event(struct input_dev *dev,
364 unsigned int type, unsigned int code, int value)
365 {
366 int disposition;
368 disposition = input_get_disposition(dev, type, code, value);
370 if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
371 dev->event(dev, type, code, value);
373 if (!dev->vals)
374 return;
376 if (disposition & INPUT_PASS_TO_HANDLERS) {
377 struct input_value *v;
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 }
386 v = &dev->vals[dev->num_vals++];
387 v->type = type;
388 v->code = code;
389 v->value = value;
390 }
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 }
402 }
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 */
421 void input_event(struct input_dev *dev,
422 unsigned int type, unsigned int code, int value)
423 {
424 unsigned long flags;
426 if (is_event_supported(type, dev->evbit, EV_MAX)) {
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 }
433 EXPORT_SYMBOL(input_event);
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 */
446 void 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;
453 if (is_event_supported(type, dev->evbit, EV_MAX)) {
454 spin_lock_irqsave(&dev->event_lock, flags);
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();
462 spin_unlock_irqrestore(&dev->event_lock, flags);
463 }
464 }
465 EXPORT_SYMBOL(input_inject_event);
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 */
474 void 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);
480 WARN(!dev->absinfo, "%s(): kcalloc() failed?\n", __func__);
481 }
482 EXPORT_SYMBOL(input_alloc_absinfo);
484 void 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;
489 input_alloc_absinfo(dev);
490 if (!dev->absinfo)
491 return;
493 absinfo = &dev->absinfo[axis];
494 absinfo->minimum = min;
495 absinfo->maximum = max;
496 absinfo->fuzz = fuzz;
497 absinfo->flat = flat;
499 dev->absbit[BIT_WORD(axis)] |= BIT_MASK(axis);
500 }
501 EXPORT_SYMBOL(input_set_abs_params);
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 */
512 int input_grab_device(struct input_handle *handle)
513 {
514 struct input_dev *dev = handle->dev;
515 int retval;
517 retval = mutex_lock_interruptible(&dev->mutex);
518 if (retval)
519 return retval;
521 if (dev->grab) {
522 retval = -EBUSY;
523 goto out;
524 }
526 rcu_assign_pointer(dev->grab, handle);
528 out:
529 mutex_unlock(&dev->mutex);
530 return retval;
531 }
532 EXPORT_SYMBOL(input_grab_device);
534 static void __input_release_device(struct input_handle *handle)
535 {
536 struct input_dev *dev = handle->dev;
537 struct input_handle *grabber;
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();
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 }
552 /**
553 * input_release_device - release previously grabbed device
554 * @handle: input handle that owns the device
555 *
556 * Releases previously grabbed device so that other input handles can
557 * start receiving input events. Upon release all handlers attached
558 * to the device have their start() method called so they have a change
559 * to synchronize device state with the rest of the system.
560 */
561 void input_release_device(struct input_handle *handle)
562 {
563 struct input_dev *dev = handle->dev;
565 mutex_lock(&dev->mutex);
566 __input_release_device(handle);
567 mutex_unlock(&dev->mutex);
568 }
569 EXPORT_SYMBOL(input_release_device);
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 */
578 int input_open_device(struct input_handle *handle)
579 {
580 struct input_dev *dev = handle->dev;
581 int retval;
583 retval = mutex_lock_interruptible(&dev->mutex);
584 if (retval)
585 return retval;
587 if (dev->going_away) {
588 retval = -ENODEV;
589 goto out;
590 }
592 handle->open++;
594 if (!dev->users++ && dev->open)
595 retval = dev->open(dev);
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 }
608 out:
609 mutex_unlock(&dev->mutex);
610 return retval;
611 }
612 EXPORT_SYMBOL(input_open_device);
614 int input_flush_device(struct input_handle *handle, struct file *file)
615 {
616 struct input_dev *dev = handle->dev;
617 int retval;
619 retval = mutex_lock_interruptible(&dev->mutex);
620 if (retval)
621 return retval;
623 if (dev->flush)
624 retval = dev->flush(dev, file);
626 mutex_unlock(&dev->mutex);
627 return retval;
628 }
629 EXPORT_SYMBOL(input_flush_device);
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 */
638 void input_close_device(struct input_handle *handle)
639 {
640 struct input_dev *dev = handle->dev;
642 mutex_lock(&dev->mutex);
644 __input_release_device(handle);
646 if (!--dev->users && dev->close)
647 dev->close(dev);
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 }
658 mutex_unlock(&dev->mutex);
659 }
660 EXPORT_SYMBOL(input_close_device);
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 */
666 static void input_dev_release_keys(struct input_dev *dev)
667 {
668 int code;
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 }
681 /*
682 * Prepare device for unregistering
683 */
684 static void input_disconnect_device(struct input_dev *dev)
685 {
686 struct input_handle *handle;
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);
697 spin_lock_irq(&dev->event_lock);
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);
707 list_for_each_entry(handle, &dev->h_list, d_node)
708 handle->open = 0;
710 spin_unlock_irq(&dev->event_lock);
711 }
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 */
723 int 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;
731 case 2:
732 *scancode = *((u16 *)ke->scancode);
733 break;
735 case 4:
736 *scancode = *((u32 *)ke->scancode);
737 break;
739 default:
740 return -EINVAL;
741 }
743 return 0;
744 }
745 EXPORT_SYMBOL(input_scancode_to_scalar);
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 */
752 static 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];
759 case 2:
760 return ((u16 *)dev->keycode)[index];
762 default:
763 return ((u32 *)dev->keycode)[index];
764 }
765 }
767 static int input_default_getkeycode(struct input_dev *dev,
768 struct input_keymap_entry *ke)
769 {
770 unsigned int index;
771 int error;
773 if (!dev->keycodesize)
774 return -EINVAL;
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 }
784 if (index >= dev->keycodemax)
785 return -EINVAL;
787 ke->keycode = input_fetch_keycode(dev, index);
788 ke->index = index;
789 ke->len = sizeof(index);
790 memcpy(ke->scancode, &index, sizeof(index));
792 return 0;
793 }
795 static 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;
803 if (!dev->keycodesize)
804 return -EINVAL;
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 }
814 if (index >= dev->keycodemax)
815 return -EINVAL;
817 if (dev->keycodesize < sizeof(ke->keycode) &&
818 (ke->keycode >> (dev->keycodesize * 8)))
819 return -EINVAL;
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 }
842 __clear_bit(*old_keycode, dev->keybit);
843 __set_bit(ke->keycode, dev->keybit);
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 }
852 return 0;
853 }
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 */
863 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
864 {
865 unsigned long flags;
866 int retval;
868 spin_lock_irqsave(&dev->event_lock, flags);
869 retval = dev->getkeycode(dev, ke);
870 spin_unlock_irqrestore(&dev->event_lock, flags);
872 return retval;
873 }
874 EXPORT_SYMBOL(input_get_keycode);
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 */
884 int 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;
891 if (ke->keycode > KEY_MAX)
892 return -EINVAL;
894 spin_lock_irqsave(&dev->event_lock, flags);
896 retval = dev->setkeycode(dev, ke, &old_keycode);
897 if (retval)
898 goto out;
900 /* Make sure KEY_RESERVED did not get enabled. */
901 __clear_bit(KEY_RESERVED, dev->keybit);
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 };
915 input_pass_values(dev, vals, ARRAY_SIZE(vals));
916 }
918 out:
919 spin_unlock_irqrestore(&dev->event_lock, flags);
921 return retval;
922 }
923 EXPORT_SYMBOL(input_set_keycode);
925 static 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;
930 for (id = handler->id_table; id->flags || id->driver_info; id++) {
932 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
933 if (id->bustype != dev->id.bustype)
934 continue;
936 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
937 if (id->vendor != dev->id.vendor)
938 continue;
940 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
941 if (id->product != dev->id.product)
942 continue;
944 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
945 if (id->version != dev->id.version)
946 continue;
948 if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX))
949 continue;
951 if (!bitmap_subset(id->keybit, dev->keybit, KEY_MAX))
952 continue;
954 if (!bitmap_subset(id->relbit, dev->relbit, REL_MAX))
955 continue;
957 if (!bitmap_subset(id->absbit, dev->absbit, ABS_MAX))
958 continue;
960 if (!bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX))
961 continue;
963 if (!bitmap_subset(id->ledbit, dev->ledbit, LED_MAX))
964 continue;
966 if (!bitmap_subset(id->sndbit, dev->sndbit, SND_MAX))
967 continue;
969 if (!bitmap_subset(id->ffbit, dev->ffbit, FF_MAX))
970 continue;
972 if (!bitmap_subset(id->swbit, dev->swbit, SW_MAX))
973 continue;
975 if (!handler->match || handler->match(handler, dev))
976 return id;
977 }
979 return NULL;
980 }
982 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
983 {
984 const struct input_device_id *id;
985 int error;
987 id = input_match_device(handler, dev);
988 if (!id)
989 return -ENODEV;
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);
996 return error;
997 }
999 #ifdef CONFIG_COMPAT
1001 static int input_bits_to_string(char *buf, int buf_size,
1002 unsigned long bits, bool skip_empty)
1003 {
1004 int len = 0;
1006 if (INPUT_COMPAT_TEST) {
1007 u32 dword = bits >> 32;
1008 if (dword || !skip_empty)
1009 len += snprintf(buf, buf_size, "%x ", dword);
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 }
1020 return len;
1021 }
1023 #else /* !CONFIG_COMPAT */
1025 static 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 }
1032 #endif
1034 #ifdef CONFIG_PROC_FS
1036 static struct proc_dir_entry *proc_bus_input_dir;
1037 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1038 static int input_devices_state;
1040 static inline void input_wakeup_procfs_readers(void)
1041 {
1042 input_devices_state++;
1043 wake_up(&input_devices_poll_wait);
1044 }
1046 static 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 }
1054 return 0;
1055 }
1057 union input_seq_state {
1058 struct {
1059 unsigned short pos;
1060 bool mutex_acquired;
1061 };
1062 void *p;
1063 };
1065 static 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;
1070 /* We need to fit into seq->private pointer */
1071 BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1073 error = mutex_lock_interruptible(&input_mutex);
1074 if (error) {
1075 state->mutex_acquired = false;
1076 return ERR_PTR(error);
1077 }
1079 state->mutex_acquired = true;
1081 return seq_list_start(&input_dev_list, *pos);
1082 }
1084 static 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 }
1089 static void input_seq_stop(struct seq_file *seq, void *v)
1090 {
1091 union input_seq_state *state = (union input_seq_state *)&seq->private;
1093 if (state->mutex_acquired)
1094 mutex_unlock(&input_mutex);
1095 }
1097 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1098 unsigned long *bitmap, int max)
1099 {
1100 int i;
1101 bool skip_empty = true;
1102 char buf[18];
1104 seq_printf(seq, "B: %s=", name);
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 }
1114 /*
1115 * If no output was produced print a single 0.
1116 */
1117 if (skip_empty)
1118 seq_puts(seq, "0");
1120 seq_putc(seq, '\n');
1121 }
1123 static int input_devices_seq_show(struct seq_file *seq, void *v)
1124 {
1125 struct input_dev *dev = container_of(v, struct input_dev, node);
1126 const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1127 struct input_handle *handle;
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);
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=");
1138 list_for_each_entry(handle, &dev->h_list, d_node)
1139 seq_printf(seq, "%s ", handle->name);
1140 seq_putc(seq, '\n');
1142 input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
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);
1162 seq_putc(seq, '\n');
1164 kfree(path);
1165 return 0;
1166 }
1168 static const struct seq_operations input_devices_seq_ops = {
1169 .start = input_devices_seq_start,
1170 .next = input_devices_seq_next,
1171 .stop = input_seq_stop,
1172 .show = input_devices_seq_show,
1173 };
1175 static int input_proc_devices_open(struct inode *inode, struct file *file)
1176 {
1177 return seq_open(file, &input_devices_seq_ops);
1178 }
1180 static 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 };
1189 static 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;
1194 /* We need to fit into seq->private pointer */
1195 BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1197 error = mutex_lock_interruptible(&input_mutex);
1198 if (error) {
1199 state->mutex_acquired = false;
1200 return ERR_PTR(error);
1201 }
1203 state->mutex_acquired = true;
1204 state->pos = *pos;
1206 return seq_list_start(&input_handler_list, *pos);
1207 }
1209 static 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;
1213 state->pos = *pos + 1;
1214 return seq_list_next(v, &input_handler_list, pos);
1215 }
1217 static 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;
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');
1229 return 0;
1230 }
1232 static 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 };
1239 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1240 {
1241 return seq_open(file, &input_handlers_seq_ops);
1242 }
1244 static 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 };
1252 static int __init input_proc_init(void)
1253 {
1254 struct proc_dir_entry *entry;
1256 proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1257 if (!proc_bus_input_dir)
1258 return -ENOMEM;
1260 entry = proc_create("devices", 0, proc_bus_input_dir,
1261 &input_devices_fileops);
1262 if (!entry)
1263 goto fail1;
1265 entry = proc_create("handlers", 0, proc_bus_input_dir,
1266 &input_handlers_fileops);
1267 if (!entry)
1268 goto fail2;
1270 return 0;
1272 fail2: remove_proc_entry("devices", proc_bus_input_dir);
1273 fail1: remove_proc_entry("bus/input", NULL);
1274 return -ENOMEM;
1275 }
1277 static 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 }
1284 #else /* !CONFIG_PROC_FS */
1285 static inline void input_wakeup_procfs_readers(void) { }
1286 static inline int input_proc_init(void) { return 0; }
1287 static inline void input_proc_exit(void) { }
1288 #endif
1290 #define INPUT_DEV_STRING_ATTR_SHOW(name) \
1291 static 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 } \
1300 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1302 INPUT_DEV_STRING_ATTR_SHOW(name);
1303 INPUT_DEV_STRING_ATTR_SHOW(phys);
1304 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1306 static 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;
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 }
1319 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1320 int add_cr)
1321 {
1322 int len;
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);
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);
1348 if (add_cr)
1349 len += snprintf(buf + len, max(size - len, 0), "\n");
1351 return len;
1352 }
1354 static 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;
1361 len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1363 return min_t(int, len, PAGE_SIZE);
1364 }
1365 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1367 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1368 int max, int add_cr);
1370 static 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 }
1379 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1381 static 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 };
1390 static struct attribute_group input_dev_attr_group = {
1391 .attrs = input_dev_attrs,
1392 };
1394 #define INPUT_DEV_ID_ATTR(name) \
1395 static 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 } \
1402 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1404 INPUT_DEV_ID_ATTR(bustype);
1405 INPUT_DEV_ID_ATTR(vendor);
1406 INPUT_DEV_ID_ATTR(product);
1407 INPUT_DEV_ID_ATTR(version);
1409 static 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 };
1417 static struct attribute_group input_dev_id_attr_group = {
1418 .name = "id",
1419 .attrs = input_dev_id_attrs,
1420 };
1422 static 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;
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 }
1439 /*
1440 * If no output was produced print a single 0.
1441 */
1442 if (len == 0)
1443 len = snprintf(buf, buf_size, "%d", 0);
1445 if (add_cr)
1446 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1448 return len;
1449 }
1451 #define INPUT_DEV_CAP_ATTR(ev, bm) \
1452 static 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 } \
1462 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1464 INPUT_DEV_CAP_ATTR(EV, ev);
1465 INPUT_DEV_CAP_ATTR(KEY, key);
1466 INPUT_DEV_CAP_ATTR(REL, rel);
1467 INPUT_DEV_CAP_ATTR(ABS, abs);
1468 INPUT_DEV_CAP_ATTR(MSC, msc);
1469 INPUT_DEV_CAP_ATTR(LED, led);
1470 INPUT_DEV_CAP_ATTR(SND, snd);
1471 INPUT_DEV_CAP_ATTR(FF, ff);
1472 INPUT_DEV_CAP_ATTR(SW, sw);
1474 static 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 };
1487 static struct attribute_group input_dev_caps_attr_group = {
1488 .name = "capabilities",
1489 .attrs = input_dev_caps_attrs,
1490 };
1492 static 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 };
1499 static void input_dev_release(struct device *device)
1500 {
1501 struct input_dev *dev = to_input_dev(device);
1503 input_ff_destroy(dev);
1504 input_mt_destroy_slots(dev);
1505 kfree(dev->absinfo);
1506 kfree(dev->vals);
1507 kfree(dev);
1509 module_put(THIS_MODULE);
1510 }
1512 /*
1513 * Input uevent interface - loading event handlers based on
1514 * device bitfields.
1515 */
1516 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1517 const char *name, unsigned long *bitmap, int max)
1518 {
1519 int len;
1521 if (add_uevent_var(env, "%s", name))
1522 return -ENOMEM;
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;
1530 env->buflen += len;
1531 return 0;
1532 }
1534 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1535 struct input_dev *dev)
1536 {
1537 int len;
1539 if (add_uevent_var(env, "MODALIAS="))
1540 return -ENOMEM;
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;
1548 env->buflen += len;
1549 return 0;
1550 }
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)
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)
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)
1573 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1574 {
1575 struct input_dev *dev = to_input_dev(device);
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);
1587 INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
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);
1607 INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1609 return 0;
1610 }
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)
1632 static void input_dev_toggle(struct input_dev *dev, bool activate)
1633 {
1634 if (!dev->event)
1635 return;
1637 INPUT_DO_TOGGLE(dev, LED, led, activate);
1638 INPUT_DO_TOGGLE(dev, SND, snd, activate);
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 }
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 */
1654 void input_reset_device(struct input_dev *dev)
1655 {
1656 mutex_lock(&dev->mutex);
1658 if (dev->users) {
1659 input_dev_toggle(dev, true);
1661 /*
1662 * Keys that have been pressed at suspend time are unlikely
1663 * to be still pressed when we resume.
1664 */
1665 spin_lock_irq(&dev->event_lock);
1666 input_dev_release_keys(dev);
1667 spin_unlock_irq(&dev->event_lock);
1668 }
1670 mutex_unlock(&dev->mutex);
1671 }
1672 EXPORT_SYMBOL(input_reset_device);
1674 #ifdef CONFIG_PM
1675 static int input_dev_suspend(struct device *dev)
1676 {
1677 struct input_dev *input_dev = to_input_dev(dev);
1679 mutex_lock(&input_dev->mutex);
1681 if (input_dev->users)
1682 input_dev_toggle(input_dev, false);
1684 mutex_unlock(&input_dev->mutex);
1686 return 0;
1687 }
1689 static int input_dev_resume(struct device *dev)
1690 {
1691 struct input_dev *input_dev = to_input_dev(dev);
1693 input_reset_device(input_dev);
1695 return 0;
1696 }
1698 static const struct dev_pm_ops input_dev_pm_ops = {
1699 .suspend = input_dev_suspend,
1700 .resume = input_dev_resume,
1701 .poweroff = input_dev_suspend,
1702 .restore = input_dev_resume,
1703 };
1704 #endif /* CONFIG_PM */
1706 static struct device_type input_dev_type = {
1707 .groups = input_dev_attr_groups,
1708 .release = input_dev_release,
1709 .uevent = input_dev_uevent,
1710 #ifdef CONFIG_PM
1711 .pm = &input_dev_pm_ops,
1712 #endif
1713 };
1715 static char *input_devnode(struct device *dev, umode_t *mode)
1716 {
1717 return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1718 }
1720 struct class input_class = {
1721 .name = "input",
1722 .devnode = input_devnode,
1723 };
1724 EXPORT_SYMBOL_GPL(input_class);
1726 /**
1727 * input_allocate_device - allocate memory for new input device
1728 *
1729 * Returns prepared struct input_dev or %NULL.
1730 *
1731 * NOTE: Use input_free_device() to free devices that have not been
1732 * registered; input_unregister_device() should be used for already
1733 * registered devices.
1734 */
1735 struct input_dev *input_allocate_device(void)
1736 {
1737 struct input_dev *dev;
1739 dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
1740 if (dev) {
1741 dev->dev.type = &input_dev_type;
1742 dev->dev.class = &input_class;
1743 device_initialize(&dev->dev);
1744 mutex_init(&dev->mutex);
1745 spin_lock_init(&dev->event_lock);
1746 INIT_LIST_HEAD(&dev->h_list);
1747 INIT_LIST_HEAD(&dev->node);
1749 __module_get(THIS_MODULE);
1750 }
1752 return dev;
1753 }
1754 EXPORT_SYMBOL(input_allocate_device);
1756 struct input_devres {
1757 struct input_dev *input;
1758 };
1760 static int devm_input_device_match(struct device *dev, void *res, void *data)
1761 {
1762 struct input_devres *devres = res;
1764 return devres->input == data;
1765 }
1767 static void devm_input_device_release(struct device *dev, void *res)
1768 {
1769 struct input_devres *devres = res;
1770 struct input_dev *input = devres->input;
1772 dev_dbg(dev, "%s: dropping reference to %s\n",
1773 __func__, dev_name(&input->dev));
1774 input_put_device(input);
1775 }
1777 /**
1778 * devm_input_allocate_device - allocate managed input device
1779 * @dev: device owning the input device being created
1780 *
1781 * Returns prepared struct input_dev or %NULL.
1782 *
1783 * Managed input devices do not need to be explicitly unregistered or
1784 * freed as it will be done automatically when owner device unbinds from
1785 * its driver (or binding fails). Once managed input device is allocated,
1786 * it is ready to be set up and registered in the same fashion as regular
1787 * input device. There are no special devm_input_device_[un]register()
1788 * variants, regular ones work with both managed and unmanaged devices,
1789 * should you need them. In most cases however, managed input device need
1790 * not be explicitly unregistered or freed.
1791 *
1792 * NOTE: the owner device is set up as parent of input device and users
1793 * should not override it.
1794 */
1795 struct input_dev *devm_input_allocate_device(struct device *dev)
1796 {
1797 struct input_dev *input;
1798 struct input_devres *devres;
1800 devres = devres_alloc(devm_input_device_release,
1801 sizeof(struct input_devres), GFP_KERNEL);
1802 if (!devres)
1803 return NULL;
1805 input = input_allocate_device();
1806 if (!input) {
1807 devres_free(devres);
1808 return NULL;
1809 }
1811 input->dev.parent = dev;
1812 input->devres_managed = true;
1814 devres->input = input;
1815 devres_add(dev, devres);
1817 return input;
1818 }
1819 EXPORT_SYMBOL(devm_input_allocate_device);
1821 /**
1822 * input_free_device - free memory occupied by input_dev structure
1823 * @dev: input device to free
1824 *
1825 * This function should only be used if input_register_device()
1826 * was not called yet or if it failed. Once device was registered
1827 * use input_unregister_device() and memory will be freed once last
1828 * reference to the device is dropped.
1829 *
1830 * Device should be allocated by input_allocate_device().
1831 *
1832 * NOTE: If there are references to the input device then memory
1833 * will not be freed until last reference is dropped.
1834 */
1835 void input_free_device(struct input_dev *dev)
1836 {
1837 if (dev) {
1838 if (dev->devres_managed)
1839 WARN_ON(devres_destroy(dev->dev.parent,
1840 devm_input_device_release,
1841 devm_input_device_match,
1842 dev));
1843 input_put_device(dev);
1844 }
1845 }
1846 EXPORT_SYMBOL(input_free_device);
1848 /**
1849 * input_set_capability - mark device as capable of a certain event
1850 * @dev: device that is capable of emitting or accepting event
1851 * @type: type of the event (EV_KEY, EV_REL, etc...)
1852 * @code: event code
1853 *
1854 * In addition to setting up corresponding bit in appropriate capability
1855 * bitmap the function also adjusts dev->evbit.
1856 */
1857 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1858 {
1859 switch (type) {
1860 case EV_KEY:
1861 __set_bit(code, dev->keybit);
1862 break;
1864 case EV_REL:
1865 __set_bit(code, dev->relbit);
1866 break;
1868 case EV_ABS:
1869 __set_bit(code, dev->absbit);
1870 break;
1872 case EV_MSC:
1873 __set_bit(code, dev->mscbit);
1874 break;
1876 case EV_SW:
1877 __set_bit(code, dev->swbit);
1878 break;
1880 case EV_LED:
1881 __set_bit(code, dev->ledbit);
1882 break;
1884 case EV_SND:
1885 __set_bit(code, dev->sndbit);
1886 break;
1888 case EV_FF:
1889 __set_bit(code, dev->ffbit);
1890 break;
1892 case EV_PWR:
1893 /* do nothing */
1894 break;
1896 default:
1897 pr_err("input_set_capability: unknown type %u (code %u)\n",
1898 type, code);
1899 dump_stack();
1900 return;
1901 }
1903 __set_bit(type, dev->evbit);
1904 }
1905 EXPORT_SYMBOL(input_set_capability);
1907 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
1908 {
1909 int mt_slots;
1910 int i;
1911 unsigned int events;
1913 if (dev->mt) {
1914 mt_slots = dev->mt->num_slots;
1915 } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
1916 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
1917 dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
1918 mt_slots = clamp(mt_slots, 2, 32);
1919 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
1920 mt_slots = 2;
1921 } else {
1922 mt_slots = 0;
1923 }
1925 events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
1927 for (i = 0; i < ABS_CNT; i++) {
1928 if (test_bit(i, dev->absbit)) {
1929 if (input_is_mt_axis(i))
1930 events += mt_slots;
1931 else
1932 events++;
1933 }
1934 }
1936 for (i = 0; i < REL_CNT; i++)
1937 if (test_bit(i, dev->relbit))
1938 events++;
1940 /* Make room for KEY and MSC events */
1941 events += 7;
1943 return events;
1944 }
1946 #define INPUT_CLEANSE_BITMASK(dev, type, bits) \
1947 do { \
1948 if (!test_bit(EV_##type, dev->evbit)) \
1949 memset(dev->bits##bit, 0, \
1950 sizeof(dev->bits##bit)); \
1951 } while (0)
1953 static void input_cleanse_bitmasks(struct input_dev *dev)
1954 {
1955 INPUT_CLEANSE_BITMASK(dev, KEY, key);
1956 INPUT_CLEANSE_BITMASK(dev, REL, rel);
1957 INPUT_CLEANSE_BITMASK(dev, ABS, abs);
1958 INPUT_CLEANSE_BITMASK(dev, MSC, msc);
1959 INPUT_CLEANSE_BITMASK(dev, LED, led);
1960 INPUT_CLEANSE_BITMASK(dev, SND, snd);
1961 INPUT_CLEANSE_BITMASK(dev, FF, ff);
1962 INPUT_CLEANSE_BITMASK(dev, SW, sw);
1963 }
1965 static void __input_unregister_device(struct input_dev *dev)
1966 {
1967 struct input_handle *handle, *next;
1969 input_disconnect_device(dev);
1971 mutex_lock(&input_mutex);
1973 list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
1974 handle->handler->disconnect(handle);
1975 WARN_ON(!list_empty(&dev->h_list));
1977 del_timer_sync(&dev->timer);
1978 list_del_init(&dev->node);
1980 input_wakeup_procfs_readers();
1982 mutex_unlock(&input_mutex);
1984 device_del(&dev->dev);
1985 }
1987 static void devm_input_device_unregister(struct device *dev, void *res)
1988 {
1989 struct input_devres *devres = res;
1990 struct input_dev *input = devres->input;
1992 dev_dbg(dev, "%s: unregistering device %s\n",
1993 __func__, dev_name(&input->dev));
1994 __input_unregister_device(input);
1995 }
1997 /**
1998 * input_register_device - register device with input core
1999 * @dev: device to be registered
2000 *
2001 * This function registers device with input core. The device must be
2002 * allocated with input_allocate_device() and all it's capabilities
2003 * set up before registering.
2004 * If function fails the device must be freed with input_free_device().
2005 * Once device has been successfully registered it can be unregistered
2006 * with input_unregister_device(); input_free_device() should not be
2007 * called in this case.
2008 *
2009 * Note that this function is also used to register managed input devices
2010 * (ones allocated with devm_input_allocate_device()). Such managed input
2011 * devices need not be explicitly unregistered or freed, their tear down
2012 * is controlled by the devres infrastructure. It is also worth noting
2013 * that tear down of managed input devices is internally a 2-step process:
2014 * registered managed input device is first unregistered, but stays in
2015 * memory and can still handle input_event() calls (although events will
2016 * not be delivered anywhere). The freeing of managed input device will
2017 * happen later, when devres stack is unwound to the point where device
2018 * allocation was made.
2019 */
2020 int input_register_device(struct input_dev *dev)
2021 {
2022 static atomic_t input_no = ATOMIC_INIT(0);
2023 struct input_devres *devres = NULL;
2024 struct input_handler *handler;
2025 unsigned int packet_size;
2026 const char *path;
2027 int error;
2029 if (dev->devres_managed) {
2030 devres = devres_alloc(devm_input_device_unregister,
2031 sizeof(struct input_devres), GFP_KERNEL);
2032 if (!devres)
2033 return -ENOMEM;
2035 devres->input = dev;
2036 }
2038 /* Every input device generates EV_SYN/SYN_REPORT events. */
2039 __set_bit(EV_SYN, dev->evbit);
2041 /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2042 __clear_bit(KEY_RESERVED, dev->keybit);
2044 /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2045 input_cleanse_bitmasks(dev);
2047 packet_size = input_estimate_events_per_packet(dev);
2048 if (dev->hint_events_per_packet < packet_size)
2049 dev->hint_events_per_packet = packet_size;
2051 dev->max_vals = max(dev->hint_events_per_packet, packet_size) + 2;
2052 dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2053 if (!dev->vals) {
2054 error = -ENOMEM;
2055 goto err_devres_free;
2056 }
2058 /*
2059 * If delay and period are pre-set by the driver, then autorepeating
2060 * is handled by the driver itself and we don't do it in input.c.
2061 */
2062 init_timer(&dev->timer);
2063 if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
2064 dev->timer.data = (long) dev;
2065 dev->timer.function = input_repeat_key;
2066 dev->rep[REP_DELAY] = 250;
2067 dev->rep[REP_PERIOD] = 33;
2068 }
2070 if (!dev->getkeycode)
2071 dev->getkeycode = input_default_getkeycode;
2073 if (!dev->setkeycode)
2074 dev->setkeycode = input_default_setkeycode;
2076 dev_set_name(&dev->dev, "input%ld",
2077 (unsigned long) atomic_inc_return(&input_no) - 1);
2079 error = device_add(&dev->dev);
2080 if (error)
2081 goto err_free_vals;
2083 path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2084 pr_info("%s as %s\n",
2085 dev->name ? dev->name : "Unspecified device",
2086 path ? path : "N/A");
2087 kfree(path);
2089 error = mutex_lock_interruptible(&input_mutex);
2090 if (error)
2091 goto err_device_del;
2093 list_add_tail(&dev->node, &input_dev_list);
2095 list_for_each_entry(handler, &input_handler_list, node)
2096 input_attach_handler(dev, handler);
2098 input_wakeup_procfs_readers();
2100 mutex_unlock(&input_mutex);
2102 if (dev->devres_managed) {
2103 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2104 __func__, dev_name(&dev->dev));
2105 devres_add(dev->dev.parent, devres);
2106 }
2107 return 0;
2109 err_device_del:
2110 device_del(&dev->dev);
2111 err_free_vals:
2112 kfree(dev->vals);
2113 dev->vals = NULL;
2114 err_devres_free:
2115 devres_free(devres);
2116 return error;
2117 }
2118 EXPORT_SYMBOL(input_register_device);
2120 /**
2121 * input_unregister_device - unregister previously registered device
2122 * @dev: device to be unregistered
2123 *
2124 * This function unregisters an input device. Once device is unregistered
2125 * the caller should not try to access it as it may get freed at any moment.
2126 */
2127 void input_unregister_device(struct input_dev *dev)
2128 {
2129 if (dev->devres_managed) {
2130 WARN_ON(devres_destroy(dev->dev.parent,
2131 devm_input_device_unregister,
2132 devm_input_device_match,
2133 dev));
2134 __input_unregister_device(dev);
2135 /*
2136 * We do not do input_put_device() here because it will be done
2137 * when 2nd devres fires up.
2138 */
2139 } else {
2140 __input_unregister_device(dev);
2141 input_put_device(dev);
2142 }
2143 }
2144 EXPORT_SYMBOL(input_unregister_device);
2146 /**
2147 * input_register_handler - register a new input handler
2148 * @handler: handler to be registered
2149 *
2150 * This function registers a new input handler (interface) for input
2151 * devices in the system and attaches it to all input devices that
2152 * are compatible with the handler.
2153 */
2154 int input_register_handler(struct input_handler *handler)
2155 {
2156 struct input_dev *dev;
2157 int error;
2159 error = mutex_lock_interruptible(&input_mutex);
2160 if (error)
2161 return error;
2163 INIT_LIST_HEAD(&handler->h_list);
2165 list_add_tail(&handler->node, &input_handler_list);
2167 list_for_each_entry(dev, &input_dev_list, node)
2168 input_attach_handler(dev, handler);
2170 input_wakeup_procfs_readers();
2172 mutex_unlock(&input_mutex);
2173 return 0;
2174 }
2175 EXPORT_SYMBOL(input_register_handler);
2177 /**
2178 * input_unregister_handler - unregisters an input handler
2179 * @handler: handler to be unregistered
2180 *
2181 * This function disconnects a handler from its input devices and
2182 * removes it from lists of known handlers.
2183 */
2184 void input_unregister_handler(struct input_handler *handler)
2185 {
2186 struct input_handle *handle, *next;
2188 mutex_lock(&input_mutex);
2190 list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2191 handler->disconnect(handle);
2192 WARN_ON(!list_empty(&handler->h_list));
2194 list_del_init(&handler->node);
2196 input_wakeup_procfs_readers();
2198 mutex_unlock(&input_mutex);
2199 }
2200 EXPORT_SYMBOL(input_unregister_handler);
2202 /**
2203 * input_handler_for_each_handle - handle iterator
2204 * @handler: input handler to iterate
2205 * @data: data for the callback
2206 * @fn: function to be called for each handle
2207 *
2208 * Iterate over @bus's list of devices, and call @fn for each, passing
2209 * it @data and stop when @fn returns a non-zero value. The function is
2210 * using RCU to traverse the list and therefore may be usind in atonic
2211 * contexts. The @fn callback is invoked from RCU critical section and
2212 * thus must not sleep.
2213 */
2214 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2215 int (*fn)(struct input_handle *, void *))
2216 {
2217 struct input_handle *handle;
2218 int retval = 0;
2220 rcu_read_lock();
2222 list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2223 retval = fn(handle, data);
2224 if (retval)
2225 break;
2226 }
2228 rcu_read_unlock();
2230 return retval;
2231 }
2232 EXPORT_SYMBOL(input_handler_for_each_handle);
2234 /**
2235 * input_register_handle - register a new input handle
2236 * @handle: handle to register
2237 *
2238 * This function puts a new input handle onto device's
2239 * and handler's lists so that events can flow through
2240 * it once it is opened using input_open_device().
2241 *
2242 * This function is supposed to be called from handler's
2243 * connect() method.
2244 */
2245 int input_register_handle(struct input_handle *handle)
2246 {
2247 struct input_handler *handler = handle->handler;
2248 struct input_dev *dev = handle->dev;
2249 int error;
2251 /*
2252 * We take dev->mutex here to prevent race with
2253 * input_release_device().
2254 */
2255 error = mutex_lock_interruptible(&dev->mutex);
2256 if (error)
2257 return error;
2259 /*
2260 * Filters go to the head of the list, normal handlers
2261 * to the tail.
2262 */
2263 if (handler->filter)
2264 list_add_rcu(&handle->d_node, &dev->h_list);
2265 else
2266 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2268 mutex_unlock(&dev->mutex);
2270 /*
2271 * Since we are supposed to be called from ->connect()
2272 * which is mutually exclusive with ->disconnect()
2273 * we can't be racing with input_unregister_handle()
2274 * and so separate lock is not needed here.
2275 */
2276 list_add_tail_rcu(&handle->h_node, &handler->h_list);
2278 if (handler->start)
2279 handler->start(handle);
2281 return 0;
2282 }
2283 EXPORT_SYMBOL(input_register_handle);
2285 /**
2286 * input_unregister_handle - unregister an input handle
2287 * @handle: handle to unregister
2288 *
2289 * This function removes input handle from device's
2290 * and handler's lists.
2291 *
2292 * This function is supposed to be called from handler's
2293 * disconnect() method.
2294 */
2295 void input_unregister_handle(struct input_handle *handle)
2296 {
2297 struct input_dev *dev = handle->dev;
2299 list_del_rcu(&handle->h_node);
2301 /*
2302 * Take dev->mutex to prevent race with input_release_device().
2303 */
2304 mutex_lock(&dev->mutex);
2305 list_del_rcu(&handle->d_node);
2306 mutex_unlock(&dev->mutex);
2308 synchronize_rcu();
2309 }
2310 EXPORT_SYMBOL(input_unregister_handle);
2312 /**
2313 * input_get_new_minor - allocates a new input minor number
2314 * @legacy_base: beginning or the legacy range to be searched
2315 * @legacy_num: size of legacy range
2316 * @allow_dynamic: whether we can also take ID from the dynamic range
2317 *
2318 * This function allocates a new device minor for from input major namespace.
2319 * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2320 * parameters and whether ID can be allocated from dynamic range if there are
2321 * no free IDs in legacy range.
2322 */
2323 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2324 bool allow_dynamic)
2325 {
2326 /*
2327 * This function should be called from input handler's ->connect()
2328 * methods, which are serialized with input_mutex, so no additional
2329 * locking is needed here.
2330 */
2331 if (legacy_base >= 0) {
2332 int minor = ida_simple_get(&input_ida,
2333 legacy_base,
2334 legacy_base + legacy_num,
2335 GFP_KERNEL);
2336 if (minor >= 0 || !allow_dynamic)
2337 return minor;
2338 }
2340 return ida_simple_get(&input_ida,
2341 INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2342 GFP_KERNEL);
2343 }
2344 EXPORT_SYMBOL(input_get_new_minor);
2346 /**
2347 * input_free_minor - release previously allocated minor
2348 * @minor: minor to be released
2349 *
2350 * This function releases previously allocated input minor so that it can be
2351 * reused later.
2352 */
2353 void input_free_minor(unsigned int minor)
2354 {
2355 ida_simple_remove(&input_ida, minor);
2356 }
2357 EXPORT_SYMBOL(input_free_minor);
2359 static int __init input_init(void)
2360 {
2361 int err;
2363 err = class_register(&input_class);
2364 if (err) {
2365 pr_err("unable to register input_dev class\n");
2366 return err;
2367 }
2369 err = input_proc_init();
2370 if (err)
2371 goto fail1;
2373 err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2374 INPUT_MAX_CHAR_DEVICES, "input");
2375 if (err) {
2376 pr_err("unable to register char major %d", INPUT_MAJOR);
2377 goto fail2;
2378 }
2380 return 0;
2382 fail2: input_proc_exit();
2383 fail1: class_unregister(&input_class);
2384 return err;
2385 }
2387 static void __exit input_exit(void)
2388 {
2389 input_proc_exit();
2390 unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2391 INPUT_MAX_CHAR_DEVICES);
2392 class_unregister(&input_class);
2393 }
2395 subsys_initcall(input_init);
2396 module_exit(input_exit);