summaryrefslogtreecommitdiffstats
path: root/drivers/input/input.c
blob: efa1b1f75393f747ea8864377518b44b12bb1f82 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
/*
 * The input core
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/major.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/mutex.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION("Input core");
MODULE_LICENSE("GPL");

#define INPUT_DEVICES	256

static LIST_HEAD(input_dev_list);
static LIST_HEAD(input_handler_list);

static struct input_handler *input_table[8];

/**
 * input_event() - report new input event
 * @dev: device that generated the event
 * @type: type of the event
 * @code: event code
 * @value: value of the event
 *
 * This function should be used by drivers implementing various input devices
 * See also input_inject_event()
 */
void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
{
	struct input_handle *handle;

	if (type > EV_MAX || !test_bit(type, dev->evbit))
		return;

	add_input_randomness(type, code, value);

	switch (type) {

		case EV_SYN:
			switch (code) {
				case SYN_CONFIG:
					if (dev->event)
						dev->event(dev, type, code, value);
					break;

				case SYN_REPORT:
					if (dev->sync)
						return;
					dev->sync = 1;
					break;
			}
			break;

		case EV_KEY:

			if (code > KEY_MAX || !test_bit(code, dev->keybit) || !!test_bit(code, dev->key) == value)
				return;

			if (value == 2)
				break;

			change_bit(code, dev->key);

			if (test_bit(EV_REP, dev->evbit) && dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] && dev->timer.data && value) {
				dev->repeat_key = code;
				mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
			}

			break;

		case EV_SW:

			if (code > SW_MAX || !test_bit(code, dev->swbit) || !!test_bit(code, dev->sw) == value)
				return;

			change_bit(code, dev->sw);

			break;

		case EV_ABS:

			if (code > ABS_MAX || !test_bit(code, dev->absbit))
				return;

			if (dev->absfuzz[code]) {
				if ((value > dev->abs[code] - (dev->absfuzz[code] >> 1)) &&
				    (value < dev->abs[code] + (dev->absfuzz[code] >> 1)))
					return;

				if ((value > dev->abs[code] - dev->absfuzz[code]) &&
				    (value < dev->abs[code] + dev->absfuzz[code]))
					value = (dev->abs[code] * 3 + value) >> 2;

				if ((value > dev->abs[code] - (dev->absfuzz[code] << 1)) &&
				    (value < dev->abs[code] + (dev->absfuzz[code] << 1)))
					value = (dev->abs[code] + value) >> 1;
			}

			if (dev->abs[code] == value)
				return;

			dev->abs[code] = value;
			break;

		case EV_REL:

			if (code > REL_MAX || !test_bit(code, dev->relbit) || (value == 0))
				return;

			break;

		case EV_MSC:

			if (code > MSC_MAX || !test_bit(code, dev->mscbit))
				return;

			if (dev->event)
				dev->event(dev, type, code, value);

			break;

		case EV_LED:

			if (code > LED_MAX || !test_bit(code, dev->ledbit) || !!test_bit(code, dev->led) == value)
				return;

			change_bit(code, dev->led);

			if (dev->event)
				dev->event(dev, type, code, value);

			break;

		case EV_SND:

			if (code > SND_MAX || !test_bit(code, dev->sndbit))
				return;

			if (!!test_bit(code, dev->snd) != !!value)
				change_bit(code, dev->snd);

			if (dev->event)
				dev->event(dev, type, code, value);

			break;

		case EV_REP:

			if (code > REP_MAX || value < 0 || dev->rep[code] == value)
				return;

			dev->rep[code] = value;
			if (dev->event)
				dev->event(dev, type, code, value);

			break;

		case EV_FF:

			if (value < 0)
				return;

			if (dev->event)
				dev->event(dev, type, code, value);
			break;
	}

	if (type != EV_SYN)
		dev->sync = 0;

	if (dev->grab)
		dev->grab->handler->event(dev->grab, type, code, value);
	else
		list_for_each_entry(handle, &dev->h_list, d_node)
			if (handle->open)
				handle->handler->event(handle, type, code, value);
}
EXPORT_SYMBOL(input_event);

/**
 * input_inject_event() - send input event from input handler
 * @handle: input handle to send event through
 * @type: type of the event
 * @code: event code
 * @value: value of the event
 *
 * Similar to input_event() but will ignore event if device is "grabbed" and handle
 * injecting event is not the one that owns the device.
 */
void input_inject_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
{
	if (!handle->dev->grab || handle->dev->grab == handle)
		input_event(handle->dev, type, code, value);
}
EXPORT_SYMBOL(input_inject_event);

static void input_repeat_key(unsigned long data)
{
	struct input_dev *dev = (void *) data;

	if (!test_bit(dev->repeat_key, dev->key))
		return;

	input_event(dev, EV_KEY, dev->repeat_key, 2);
	input_sync(dev);

	if (dev->rep[REP_PERIOD])
		mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_PERIOD]));
}

int input_grab_device(struct input_handle *handle)
{
	if (handle->dev->grab)
		return -EBUSY;

	handle->dev->grab = handle;
	return 0;
}
EXPORT_SYMBOL(input_grab_device);

void input_release_device(struct input_handle *handle)
{
	struct input_dev *dev = handle->dev;

	if (dev->grab == handle) {
		dev->grab = NULL;

		list_for_each_entry(handle, &dev->h_list, d_node)
			if (handle->handler->start)
				handle->handler->start(handle);
	}
}
EXPORT_SYMBOL(input_release_device);

int input_open_device(struct input_handle *handle)
{
	struct input_dev *dev = handle->dev;
	int err;

	err = mutex_lock_interruptible(&dev->mutex);
	if (err)
		return err;

	handle->open++;

	if (!dev->users++ && dev->open)
		err = dev->open(dev);

	if (err)
		handle->open--;

	mutex_unlock(&dev->mutex);

	return err;
}
EXPORT_SYMBOL(input_open_device);

int input_flush_device(struct input_handle* handle, struct file* file)
{
	if (handle->dev->flush)
		return handle->dev->flush(handle->dev, file);

	return 0;
}
EXPORT_SYMBOL(input_flush_device);

void input_close_device(struct input_handle *handle)
{
	struct input_dev *dev = handle->dev;

	input_release_device(handle);

	mutex_lock(&dev->mutex);

	if (!--dev->users && dev->close)
		dev->close(dev);
	handle->open--;

	mutex_unlock(&dev->mutex);
}
EXPORT_SYMBOL(input_close_device);

static void input_link_handle(struct input_handle *handle)
{
	list_add_tail(&handle->d_node, &handle->dev->h_list);
	list_add_tail(&handle->h_node, &handle->handler->h_list);
}

#define MATCH_BIT(bit, max) \
		for (i = 0; i < NBITS(max); i++) \
			if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
				break; \
		if (i != NBITS(max)) \
			continue;

static const struct input_device_id *input_match_device(const struct input_device_id *id,
							struct input_dev *dev)
{
	int i;

	for (; id->flags || id->driver_info; id++) {

		if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
			if (id->bustype != dev->id.bustype)
				continue;

		if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
			if (id->vendor != dev->id.vendor)
				continue;

		if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
			if (id->product != dev->id.product)
				continue;

		if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
			if (id->version != dev->id.version)
				continue;

		MATCH_BIT(evbit,  EV_MAX);
		MATCH_BIT(keybit, KEY_MAX);
		MATCH_BIT(relbit, REL_MAX);
		MATCH_BIT(absbit, ABS_MAX);
		MATCH_BIT(mscbit, MSC_MAX);
		MATCH_BIT(ledbit, LED_MAX);
		MATCH_BIT(sndbit, SND_MAX);
		MATCH_BIT(ffbit,  FF_MAX);
		MATCH_BIT(swbit,  SW_MAX);

		return id;
	}

	return NULL;
}

#ifdef CONFIG_PROC_FS

static struct proc_dir_entry *proc_bus_input_dir;
static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
static int input_devices_state;

static inline void input_wakeup_procfs_readers(void)
{
	input_devices_state++;
	wake_up(&input_devices_poll_wait);
}

static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
{
	int state = input_devices_state;

	poll_wait(file, &input_devices_poll_wait, wait);
	if (state != input_devices_state)
		return POLLIN | POLLRDNORM;

	return 0;
}

static struct list_head *list_get_nth_element(struct list_head *list, loff_t *pos)
{
	struct list_head *node;
	loff_t i = 0;

	list_for_each(node, list)
		if (i++ == *pos)
			return node;

	return NULL;
}

static struct list_head *list_get_next_element(struct list_head *list, struct list_head *element, loff_t *pos)
{
	if (element->next == list)
		return NULL;

	++(*pos);
	return element->next;
}

static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
{
	/* acquire lock here ... Yes, we do need locking, I knowi, I know... */

	return list_get_nth_element(&input_dev_list, pos);
}

static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return list_get_next_element(&input_dev_list, v, pos);
}

static void input_devices_seq_stop(struct seq_file *seq, void *v)
{
	/* release lock here */
}

static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
				   unsigned long *bitmap, int max)
{
	int i;

	for (i = NBITS(max) - 1; i > 0; i--)
		if (bitmap[i])
			break;

	seq_printf(seq, "B: %s=", name);
	for (; i >= 0; i--)
		seq_printf(seq, "%lx%s", bitmap[i], i > 0 ? " " : "");
	seq_putc(seq, '\n');
}

static int input_devices_seq_show(struct seq_file *seq, void *v)
{
	struct input_dev *dev = container_of(v, struct input_dev, node);
	const char *path = kobject_get_path(&dev->cdev.kobj, GFP_KERNEL);
	struct input_handle *handle;

	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);

	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
	seq_printf(seq, "H: Handlers=");

	list_for_each_entry(handle, &dev->h_list, d_node)
		seq_printf(seq, "%s ", handle->name);
	seq_putc(seq, '\n');

	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
	if (test_bit(EV_KEY, dev->evbit))
		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
	if (test_bit(EV_REL, dev->evbit))
		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
	if (test_bit(EV_ABS, dev->evbit))
		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
	if (test_bit(EV_MSC, dev->evbit))
		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
	if (test_bit(EV_LED, dev->evbit))
		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
	if (test_bit(EV_SND, dev->evbit))
		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
	if (test_bit(EV_FF, dev->evbit))
		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
	if (test_bit(EV_SW, dev->evbit))
		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);

	seq_putc(seq, '\n');

	kfree(path);
	return 0;
}

static struct seq_operations input_devices_seq_ops = {
	.start	= input_devices_seq_start,
	.next	= input_devices_seq_next,
	.stop	= input_devices_seq_stop,
	.show	= input_devices_seq_show,
};

static int input_proc_devices_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &input_devices_seq_ops);
}

static const struct file_operations input_devices_fileops = {
	.owner		= THIS_MODULE,
	.open		= input_proc_devices_open,
	.poll		= input_proc_devices_poll,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
{
	/* acquire lock here ... Yes, we do need locking, I knowi, I know... */
	seq->private = (void *)(unsigned long)*pos;
	return list_get_nth_element(&input_handler_list, pos);
}

static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	seq->private = (void *)(unsigned long)(*pos + 1);
	return list_get_next_element(&input_handler_list, v, pos);
}

static void input_handlers_seq_stop(struct seq_file *seq, void *v)
{
	/* release lock here */
}

static int input_handlers_seq_show(struct seq_file *seq, void *v)
{
	struct input_handler *handler = container_of(v, struct input_handler, node);

	seq_printf(seq, "N: Number=%ld Name=%s",
		   (unsigned long)seq->private, handler->name);
	if (handler->fops)
		seq_printf(seq, " Minor=%d", handler->minor);
	seq_putc(seq, '\n');

	return 0;
}
static struct seq_operations input_handlers_seq_ops = {
	.start	= input_handlers_seq_start,
	.next	= input_handlers_seq_next,
	.stop	= input_handlers_seq_stop,
	.show	= input_handlers_seq_show,
};

static int input_proc_handlers_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &input_handlers_seq_ops);
}

static const struct file_operations input_handlers_fileops = {
	.owner		= THIS_MODULE,
	.open		= input_proc_handlers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int __init input_proc_init(void)
{
	struct proc_dir_entry *entry;

	proc_bus_input_dir = proc_mkdir("input", proc_bus);
	if (!proc_bus_input_dir)
		return -ENOMEM;

	proc_bus_input_dir->owner = THIS_MODULE;

	entry = create_proc_entry("devices", 0, proc_bus_input_dir);
	if (!entry)
		goto fail1;

	entry->owner = THIS_MODULE;
	entry->proc_fops = &input_devices_fileops;

	entry = create_proc_entry("handlers", 0, proc_bus_input_dir);
	if (!entry)
		goto fail2;

	entry->owner = THIS_MODULE;
	entry->proc_fops = &input_handlers_fileops;

	return 0;

 fail2:	remove_proc_entry("devices", proc_bus_input_dir);
 fail1: remove_proc_entry("input", proc_bus);
	return -ENOMEM;
}

static void input_proc_exit(void)
{
	remove_proc_entry("devices", proc_bus_input_dir);
	remove_proc_entry("handlers", proc_bus_input_dir);
	remove_proc_entry("input", proc_bus);
}

#else /* !CONFIG_PROC_FS */
static inline void input_wakeup_procfs_readers(void) { }
static inline int input_proc_init(void) { return 0; }
static inline void input_proc_exit(void) { }
#endif

#define INPUT_DEV_STRING_ATTR_SHOW(name)					\
static ssize_t input_dev_show_##name(struct class_device *dev, char *buf)	\
{										\
	struct input_dev *input_dev = to_input_dev(dev);			\
	int retval;								\
										\
	retval = mutex_lock_interruptible(&input_dev->mutex);			\
	if (retval)								\
		return retval;							\
										\
	retval = scnprintf(buf, PAGE_SIZE,					\
			   "%s\n", input_dev->name ? input_dev->name : "");	\
										\
	mutex_unlock(&input_dev->mutex);					\
										\
	return retval;								\
}										\
static CLASS_DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL);

INPUT_DEV_STRING_ATTR_SHOW(name);
INPUT_DEV_STRING_ATTR_SHOW(phys);
INPUT_DEV_STRING_ATTR_SHOW(uniq);

static int input_print_modalias_bits(char *buf, int size,
				     char name, unsigned long *bm,
				     unsigned int min_bit, unsigned int max_bit)
{
	int len = 0, i;

	len += snprintf(buf, max(size, 0), "%c", name);
	for (i = min_bit; i < max_bit; i++)
		if (bm[LONG(i)] & BIT(i))
			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
	return len;
}

static int input_print_modalias(char *buf, int size, struct input_dev *id,
				int add_cr)
{
	int len;

	len = snprintf(buf, max(size, 0),
		       "input:b%04Xv%04Xp%04Xe%04X-",
		       id->id.bustype, id->id.vendor,
		       id->id.product, id->id.version);

	len += input_print_modalias_bits(buf + len, size - len,
				'e', id->evbit, 0, EV_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'r', id->relbit, 0, REL_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'a', id->absbit, 0, ABS_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'm', id->mscbit, 0, MSC_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'l', id->ledbit, 0, LED_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				's', id->sndbit, 0, SND_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'f', id->ffbit, 0, FF_MAX);
	len += input_print_modalias_bits(buf + len, size - len,
				'w', id->swbit, 0, SW_MAX);

	if (add_cr)
		len += snprintf(buf + len, max(size - len, 0), "\n");

	return len;
}

static ssize_t input_dev_show_modalias(struct class_device *dev, char *buf)
{
	struct input_dev *id = to_input_dev(dev);
	ssize_t len;

	len = input_print_modalias(buf, PAGE_SIZE, id, 1);

	return min_t(int, len, PAGE_SIZE);
}
static CLASS_DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);

static struct attribute *input_dev_attrs[] = {
	&class_device_attr_name.attr,
	&class_device_attr_phys.attr,
	&class_device_attr_uniq.attr,
	&class_device_attr_modalias.attr,
	NULL
};

static struct attribute_group input_dev_attr_group = {
	.attrs	= input_dev_attrs,
};

#define INPUT_DEV_ID_ATTR(name)							\
static ssize_t input_dev_show_id_##name(struct class_device *dev, char *buf)	\
{										\
	struct input_dev *input_dev = to_input_dev(dev);			\
	return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name);		\
}										\
static CLASS_DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL);

INPUT_DEV_ID_ATTR(bustype);
INPUT_DEV_ID_ATTR(vendor);
INPUT_DEV_ID_ATTR(product);
INPUT_DEV_ID_ATTR(version);

static struct attribute *input_dev_id_attrs[] = {
	&class_device_attr_bustype.attr,
	&class_device_attr_vendor.attr,
	&class_device_attr_product.attr,
	&class_device_attr_version.attr,
	NULL
};

static struct attribute_group input_dev_id_attr_group = {
	.name	= "id",
	.attrs	= input_dev_id_attrs,
};

static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
			      int max, int add_cr)
{
	int i;
	int len = 0;

	for (i = NBITS(max) - 1; i > 0; i--)
		if (bitmap[i])
			break;

	for (; i >= 0; i--)
		len += snprintf(buf + len, max(buf_size - len, 0),
				"%lx%s", bitmap[i], i > 0 ? " " : "");

	if (add_cr)
		len += snprintf(buf + len, max(buf_size - len, 0), "\n");

	return len;
}

#define INPUT_DEV_CAP_ATTR(ev, bm)						\
static ssize_t input_dev_show_cap_##bm(struct class_device *dev, char *buf)	\
{										\
	struct input_dev *input_dev = to_input_dev(dev);			\
	int len = input_print_bitmap(buf, PAGE_SIZE,				\
				     input_dev->bm##bit, ev##_MAX, 1);		\
	return min_t(int, len, PAGE_SIZE);					\
}										\
static CLASS_DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL);

INPUT_DEV_CAP_ATTR(EV, ev);
INPUT_DEV_CAP_ATTR(KEY, key);
INPUT_DEV_CAP_ATTR(REL, rel);
INPUT_DEV_CAP_ATTR(ABS, abs);
INPUT_DEV_CAP_ATTR(MSC, msc);
INPUT_DEV_CAP_ATTR(LED, led);
INPUT_DEV_CAP_ATTR(SND, snd);
INPUT_DEV_CAP_ATTR(FF, ff);
INPUT_DEV_CAP_ATTR(SW, sw);

static struct attribute *input_dev_caps_attrs[] = {
	&class_device_attr_ev.attr,
	&class_device_attr_key.attr,
	&class_device_attr_rel.attr,
	&class_device_attr_abs.attr,
	&class_device_attr_msc.attr,
	&class_device_attr_led.attr,
	&class_device_attr_snd.attr,
	&class_device_attr_ff.attr,
	&class_device_attr_sw.attr,
	NULL
};

static struct attribute_group input_dev_caps_attr_group = {
	.name	= "capabilities",
	.attrs	= input_dev_caps_attrs,
};

static void input_dev_release(struct class_device *class_dev)
{
	struct input_dev *dev = to_input_dev(class_dev);

	input_ff_destroy(dev);
	kfree(dev);

	module_put(THIS_MODULE);
}

/*
 * Input uevent interface - loading event handlers based on
 * device bitfields.
 */
static int input_add_uevent_bm_var(char **envp, int num_envp, int *cur_index,
				   char *buffer, int buffer_size, int *cur_len,
				   const char *name, unsigned long *bitmap, int max)
{
	if (*cur_index >= num_envp - 1)
		return -ENOMEM;

	envp[*cur_index] = buffer + *cur_len;

	*cur_len += snprintf(buffer + *cur_len, max(buffer_size - *cur_len, 0), name);
	if (*cur_len >= buffer_size)
		return -ENOMEM;

	*cur_len += input_print_bitmap(buffer + *cur_len,
					max(buffer_size - *cur_len, 0),
					bitmap, max, 0) + 1;
	if (*cur_len > buffer_size)
		return -ENOMEM;

	(*cur_index)++;
	return 0;
}

static int input_add_uevent_modalias_var(char **envp, int num_envp, int *cur_index,
					 char *buffer, int buffer_size, int *cur_len,
					 struct input_dev *dev)
{
	if (*cur_index >= num_envp - 1)
		return -ENOMEM;

	envp[*cur_index] = buffer + *cur_len;

	*cur_len += snprintf(buffer + *cur_len, max(buffer_size - *cur_len, 0),
			     "MODALIAS=");
	if (*cur_len >= buffer_size)
		return -ENOMEM;

	*cur_len += input_print_modalias(buffer + *cur_len,
					 max(buffer_size - *cur_len, 0),
					 dev, 0) + 1;
	if (*cur_len > buffer_size)
		return -ENOMEM;

	(*cur_index)++;
	return 0;
}

#define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
	do {								\
		int err = add_uevent_var(envp, num_envp, &i,		\
					buffer, buffer_size, &len,	\
					fmt, val);			\
		if (err)						\
			return err;					\
	} while (0)

#define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
	do {								\
		int err = input_add_uevent_bm_var(envp, num_envp, &i,	\
					buffer, buffer_size, &len,	\
					name, bm, max);			\
		if (err)						\
			return err;					\
	} while (0)

#define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
	do {								\
		int err = input_add_uevent_modalias_var(envp,		\
					num_envp, &i,			\
					buffer, buffer_size, &len,	\
					dev);				\
		if (err)						\
			return err;					\
	} while (0)

static int input_dev_uevent(struct class_device *cdev, char **envp,
			    int num_envp, char *buffer, int buffer_size)
{
	struct input_dev *dev = to_input_dev(cdev);
	int i = 0;
	int len = 0;

	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
				dev->id.bustype, dev->id.vendor,
				dev->id.product, dev->id.version);
	if (dev->name)
		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
	if (dev->phys)
		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
	if (dev->uniq)
		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);

	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
	if (test_bit(EV_KEY, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
	if (test_bit(EV_REL, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
	if (test_bit(EV_ABS, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
	if (test_bit(EV_MSC, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
	if (test_bit(EV_LED, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
	if (test_bit(EV_SND, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
	if (test_bit(EV_FF, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
	if (test_bit(EV_SW, dev->evbit))
		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);

	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);

	envp[i] = NULL;
	return 0;
}

struct class input_class = {
	.name			= "input",
	.release		= input_dev_release,
	.uevent			= input_dev_uevent,
};
EXPORT_SYMBOL_GPL(input_class);

/**
 * input_allocate_device - allocate memory for new input device
 *
 * Returns prepared struct input_dev or NULL.
 *
 * NOTE: Use input_free_device() to free devices that have not been
 * registered; input_unregister_device() should be used for already
 * registered devices.
 */
struct input_dev *input_allocate_device(void)
{
	struct input_dev *dev;

	dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
	if (dev) {
		dev->cdev.class = &input_class;
		class_device_initialize(&dev->cdev);
		mutex_init(&dev->mutex);
		INIT_LIST_HEAD(&dev->h_list);
		INIT_LIST_HEAD(&dev->node);

		__module_get(THIS_MODULE);
	}

	return dev;
}
EXPORT_SYMBOL(input_allocate_device);

/**
 * input_free_device - free memory occupied by input_dev structure
 * @dev: input device to free
 *
 * This function should only be used if input_register_device()
 * was not called yet or if it failed. Once device was registered
 * use input_unregister_device() and memory will be freed once last
 * refrence to the device is dropped.
 *
 * Device should be allocated by input_allocate_device().
 *
 * NOTE: If there are references to the input device then memory
 * will not be freed until last reference is dropped.
 */
void input_free_device(struct input_dev *dev)
{
	if (dev) {

		mutex_lock(&dev->mutex);
		dev->name = dev->phys = dev->uniq = NULL;
		mutex_unlock(&dev->mutex);

		input_put_device(dev);
	}
}
EXPORT_SYMBOL(input_free_device);

int input_register_device(struct input_dev *dev)
{
	static atomic_t input_no = ATOMIC_INIT(0);
	struct input_handle *handle;
	struct input_handler *handler;
	const struct input_device_id *id;
	const char *path;
	int error;

	set_bit(EV_SYN, dev->evbit);

	/*
	 * If delay and period are pre-set by the driver, then autorepeating
	 * is handled by the driver itself and we don't do it in input.c.
	 */

	init_timer(&dev->timer);
	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
		dev->timer.data = (long) dev;
		dev->timer.function = input_repeat_key;
		dev->rep[REP_DELAY] = 250;
		dev->rep[REP_PERIOD] = 33;
	}

	list_add_tail(&dev->node, &input_dev_list);

	snprintf(dev->cdev.class_id, sizeof(dev->cdev.class_id),
		 "input%ld", (unsigned long) atomic_inc_return(&input_no) - 1);

	error = class_device_add(&dev->cdev);
	if (error)
		return error;

	error = sysfs_create_group(&dev->cdev.kobj, &input_dev_attr_group);
	if (error)
		goto fail1;

	error = sysfs_create_group(&dev->cdev.kobj, &input_dev_id_attr_group);
	if (error)
		goto fail2;

	error = sysfs_create_group(&dev->cdev.kobj, &input_dev_caps_attr_group);
	if (error)
		goto fail3;

	path = kobject_get_path(&dev->cdev.kobj, GFP_KERNEL);
	printk(KERN_INFO "input: %s as %s\n",
		dev->name ? dev->name : "Unspecified device", path ? path : "N/A");
	kfree(path);

	list_for_each_entry(handler, &input_handler_list, node)
		if (!handler->blacklist || !input_match_device(handler->blacklist, dev))
			if ((id = input_match_device(handler->id_table, dev)))
				if ((handle = handler->connect(handler, dev, id))) {
					input_link_handle(handle);
					if (handler->start)
						handler->start(handle);
				}

	input_wakeup_procfs_readers();

	return 0;

 fail3:	sysfs_remove_group(&dev->cdev.kobj, &input_dev_id_attr_group);
 fail2:	sysfs_remove_group(&dev->cdev.kobj, &input_dev_attr_group);
 fail1:	class_device_del(&dev->cdev);
	return error;
}
EXPORT_SYMBOL(input_register_device);

void input_unregister_device(struct input_dev *dev)
{
	struct list_head *node, *next;
	int code;

	for (code = 0; code <= KEY_MAX; code++)
		if (test_bit(code, dev->key))
			input_report_key(dev, code, 0);
	input_sync(dev);

	del_timer_sync(&dev->timer);

	list_for_each_safe(node, next, &dev->h_list) {
		struct input_handle * handle = to_handle(node);
		list_del_init(&handle->d_node);
		list_del_init(&handle->h_node);
		handle->handler->disconnect(handle);
	}

	list_del_init(&dev->node);

	sysfs_remove_group(&dev->cdev.kobj, &input_dev_caps_attr_group);
	sysfs_remove_group(&dev->cdev.kobj, &input_dev_id_attr_group);
	sysfs_remove_group(&dev->cdev.kobj, &input_dev_attr_group);

	mutex_lock(&dev->mutex);
	dev->name = dev->phys = dev->uniq = NULL;
	mutex_unlock(&dev->mutex);

	class_device_unregister(&dev->cdev);

	input_wakeup_procfs_readers();
}
EXPORT_SYMBOL(input_unregister_device);

int input_register_handler(struct input_handler *handler)
{
	struct input_dev *dev;
	struct input_handle *handle;
	const struct input_device_id *id;

	INIT_LIST_HEAD(&handler->h_list);

	if (handler->fops != NULL) {
		if (input_table[handler->minor >> 5])
			return -EBUSY;

		input_table[handler->minor >> 5] = handler;
	}

	list_add_tail(&handler->node, &input_handler_list);

	list_for_each_entry(dev, &input_dev_list, node)
		if (!handler->blacklist || !input_match_device(handler->blacklist, dev))
			if ((id = input_match_device(handler->id_table, dev)))
				if ((handle = handler->connect(handler, dev, id))) {
					input_link_handle(handle);
					if (handler->start)
						handler->start(handle);
				}

	input_wakeup_procfs_readers();
	return 0;
}
EXPORT_SYMBOL(input_register_handler);

void input_unregister_handler(struct input_handler *handler)
{
	struct list_head *node, *next;

	list_for_each_safe(node, next, &handler->h_list) {
		struct input_handle * handle = to_handle_h(node);
		list_del_init(&handle->h_node);
		list_del_init(&handle->d_node);
		handler->disconnect(handle);
	}

	list_del_init(&handler->node);

	if (handler->fops != NULL)
		input_table[handler->minor >> 5] = NULL;

	input_wakeup_procfs_readers();
}
EXPORT_SYMBOL(input_unregister_handler);

static int input_open_file(struct inode *inode, struct file *file)
{
	struct input_handler *handler = input_table[iminor(inode) >> 5];
	const struct file_operations *old_fops, *new_fops = NULL;
	int err;

	/* No load-on-demand here? */
	if (!handler || !(new_fops = fops_get(handler->fops)))
		return -ENODEV;

	/*
	 * That's _really_ odd. Usually NULL ->open means "nothing special",
	 * not "no device". Oh, well...
	 */
	if (!new_fops->open) {
		fops_put(new_fops);
		return -ENODEV;
	}
	old_fops = file->f_op;
	file->f_op = new_fops;

	err = new_fops->open(inode, file);

	if (err) {
		fops_put(file->f_op);
		file->f_op = fops_get(old_fops);
	}
	fops_put(old_fops);
	return err;
}

static const struct file_operations input_fops = {
	.owner = THIS_MODULE,
	.open = input_open_file,
};

static int __init input_init(void)
{
	int err;

	err = class_register(&input_class);
	if (err) {
		printk(KERN_ERR "input: unable to register input_dev class\n");
		return err;
	}

	err = input_proc_init();
	if (err)
		goto fail1;

	err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
	if (err) {
		printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
		goto fail2;
	}

	return 0;

 fail2:	input_proc_exit();
 fail1:	class_unregister(&input_class);
	return err;
}

static void __exit input_exit(void)
{
	input_proc_exit();
	unregister_chrdev(INPUT_MAJOR, "input");
	class_unregister(&input_class);
}

subsys_initcall(input_init);
module_exit(input_exit);
OpenPOWER on IntegriCloud