summaryrefslogtreecommitdiffstats
path: root/drivers/extcon/extcon.c
blob: 0e40418ad287d5f0f893f3d95edd778adc41206c (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
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/extcon/extcon.c - External Connector (extcon) framework.
 *
 * Copyright (C) 2015 Samsung Electronics
 * Author: Chanwoo Choi <cw00.choi@samsung.com>
 *
 * Copyright (C) 2012 Samsung Electronics
 * Author: Donggeun Kim <dg77.kim@samsung.com>
 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * based on android/drivers/switch/switch_class.c
 * Copyright (C) 2008 Google, Inc.
 * Author: Mike Lockwood <lockwood@android.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/sysfs.h>

#include "extcon.h"

#define SUPPORTED_CABLE_MAX	32

static const struct __extcon_info {
	unsigned int type;
	unsigned int id;
	const char *name;

} extcon_info[] = {
	[EXTCON_NONE] = {
		.type = EXTCON_TYPE_MISC,
		.id = EXTCON_NONE,
		.name = "NONE",
	},

	/* USB external connector */
	[EXTCON_USB] = {
		.type = EXTCON_TYPE_USB,
		.id = EXTCON_USB,
		.name = "USB",
	},
	[EXTCON_USB_HOST] = {
		.type = EXTCON_TYPE_USB,
		.id = EXTCON_USB_HOST,
		.name = "USB-HOST",
	},

	/* Charging external connector */
	[EXTCON_CHG_USB_SDP] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_SDP,
		.name = "SDP",
	},
	[EXTCON_CHG_USB_DCP] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_DCP,
		.name = "DCP",
	},
	[EXTCON_CHG_USB_CDP] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_CDP,
		.name = "CDP",
	},
	[EXTCON_CHG_USB_ACA] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_ACA,
		.name = "ACA",
	},
	[EXTCON_CHG_USB_FAST] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_FAST,
		.name = "FAST-CHARGER",
	},
	[EXTCON_CHG_USB_SLOW] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_SLOW,
		.name = "SLOW-CHARGER",
	},
	[EXTCON_CHG_WPT] = {
		.type = EXTCON_TYPE_CHG,
		.id = EXTCON_CHG_WPT,
		.name = "WPT",
	},
	[EXTCON_CHG_USB_PD] = {
		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
		.id = EXTCON_CHG_USB_PD,
		.name = "PD",
	},

	/* Jack external connector */
	[EXTCON_JACK_MICROPHONE] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_MICROPHONE,
		.name = "MICROPHONE",
	},
	[EXTCON_JACK_HEADPHONE] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_HEADPHONE,
		.name = "HEADPHONE",
	},
	[EXTCON_JACK_LINE_IN] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_LINE_IN,
		.name = "LINE-IN",
	},
	[EXTCON_JACK_LINE_OUT] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_LINE_OUT,
		.name = "LINE-OUT",
	},
	[EXTCON_JACK_VIDEO_IN] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_VIDEO_IN,
		.name = "VIDEO-IN",
	},
	[EXTCON_JACK_VIDEO_OUT] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_VIDEO_OUT,
		.name = "VIDEO-OUT",
	},
	[EXTCON_JACK_SPDIF_IN] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_SPDIF_IN,
		.name = "SPDIF-IN",
	},
	[EXTCON_JACK_SPDIF_OUT] = {
		.type = EXTCON_TYPE_JACK,
		.id = EXTCON_JACK_SPDIF_OUT,
		.name = "SPDIF-OUT",
	},

	/* Display external connector */
	[EXTCON_DISP_HDMI] = {
		.type = EXTCON_TYPE_DISP,
		.id = EXTCON_DISP_HDMI,
		.name = "HDMI",
	},
	[EXTCON_DISP_MHL] = {
		.type = EXTCON_TYPE_DISP,
		.id = EXTCON_DISP_MHL,
		.name = "MHL",
	},
	[EXTCON_DISP_DVI] = {
		.type = EXTCON_TYPE_DISP,
		.id = EXTCON_DISP_DVI,
		.name = "DVI",
	},
	[EXTCON_DISP_VGA] = {
		.type = EXTCON_TYPE_DISP,
		.id = EXTCON_DISP_VGA,
		.name = "VGA",
	},
	[EXTCON_DISP_DP] = {
		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
		.id = EXTCON_DISP_DP,
		.name = "DP",
	},
	[EXTCON_DISP_HMD] = {
		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
		.id = EXTCON_DISP_HMD,
		.name = "HMD",
	},

	/* Miscellaneous external connector */
	[EXTCON_DOCK] = {
		.type = EXTCON_TYPE_MISC,
		.id = EXTCON_DOCK,
		.name = "DOCK",
	},
	[EXTCON_JIG] = {
		.type = EXTCON_TYPE_MISC,
		.id = EXTCON_JIG,
		.name = "JIG",
	},
	[EXTCON_MECHANICAL] = {
		.type = EXTCON_TYPE_MISC,
		.id = EXTCON_MECHANICAL,
		.name = "MECHANICAL",
	},

	{ /* sentinel */ }
};

/**
 * struct extcon_cable - An internal data for an external connector.
 * @edev:		the extcon device
 * @cable_index:	the index of this cable in the edev
 * @attr_g:		the attribute group for the cable
 * @attr_name:		"name" sysfs entry
 * @attr_state:		"state" sysfs entry
 * @attrs:		the array pointing to attr_name and attr_state for attr_g
 */
struct extcon_cable {
	struct extcon_dev *edev;
	int cable_index;

	struct attribute_group attr_g;
	struct device_attribute attr_name;
	struct device_attribute attr_state;

	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */

	union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
	union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
	union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
	union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];

	unsigned long usb_bits[BITS_TO_LONGS(EXTCON_PROP_USB_CNT)];
	unsigned long chg_bits[BITS_TO_LONGS(EXTCON_PROP_CHG_CNT)];
	unsigned long jack_bits[BITS_TO_LONGS(EXTCON_PROP_JACK_CNT)];
	unsigned long disp_bits[BITS_TO_LONGS(EXTCON_PROP_DISP_CNT)];
};

static struct class *extcon_class;

static LIST_HEAD(extcon_dev_list);
static DEFINE_MUTEX(extcon_dev_list_lock);

static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
{
	int i = 0;

	if (!edev->mutually_exclusive)
		return 0;

	for (i = 0; edev->mutually_exclusive[i]; i++) {
		int weight;
		u32 correspondants = new_state & edev->mutually_exclusive[i];

		/* calculate the total number of bits set */
		weight = hweight32(correspondants);
		if (weight > 1)
			return i + 1;
	}

	return 0;
}

static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
{
	int i;

	/* Find the index of extcon cable in edev->supported_cable */
	for (i = 0; i < edev->max_supported; i++) {
		if (edev->supported_cable[i] == id)
			return i;
	}

	return -EINVAL;
}

static int get_extcon_type(unsigned int prop)
{
	switch (prop) {
	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
		return EXTCON_TYPE_USB;
	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
		return EXTCON_TYPE_CHG;
	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
		return EXTCON_TYPE_JACK;
	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
		return EXTCON_TYPE_DISP;
	default:
		return -EINVAL;
	}
}

static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
{
	return !!(edev->state & BIT(index));
}

static bool is_extcon_changed(struct extcon_dev *edev, int index,
				bool new_state)
{
	int state = !!(edev->state & BIT(index));
	return (state != new_state);
}

static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
{
	int type;

	/* Check whether the property is supported or not. */
	type = get_extcon_type(prop);
	if (type < 0)
		return false;

	/* Check whether a specific extcon id supports the property or not. */
	return !!(extcon_info[id].type & type);
}

static int is_extcon_property_capability(struct extcon_dev *edev,
				unsigned int id, int index,unsigned int prop)
{
	struct extcon_cable *cable;
	int type, ret;

	/* Check whether the property is supported or not. */
	type = get_extcon_type(prop);
	if (type < 0)
		return type;

	cable = &edev->cables[index];

	switch (type) {
	case EXTCON_TYPE_USB:
		ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
		break;
	case EXTCON_TYPE_CHG:
		ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
		break;
	case EXTCON_TYPE_JACK:
		ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
		break;
	case EXTCON_TYPE_DISP:
		ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}

static void init_property(struct extcon_dev *edev, unsigned int id, int index)
{
	unsigned int type = extcon_info[id].type;
	struct extcon_cable *cable = &edev->cables[index];

	if (EXTCON_TYPE_USB & type)
		memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
	if (EXTCON_TYPE_CHG & type)
		memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
	if (EXTCON_TYPE_JACK & type)
		memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
	if (EXTCON_TYPE_DISP & type)
		memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
}

static ssize_t state_show(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	int i, count = 0;
	struct extcon_dev *edev = dev_get_drvdata(dev);

	if (edev->max_supported == 0)
		return sprintf(buf, "%u\n", edev->state);

	for (i = 0; i < edev->max_supported; i++) {
		count += sprintf(buf + count, "%s=%d\n",
				extcon_info[edev->supported_cable[i]].name,
				 !!(edev->state & BIT(i)));
	}

	return count;
}
static DEVICE_ATTR_RO(state);

static ssize_t name_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct extcon_dev *edev = dev_get_drvdata(dev);

	return sprintf(buf, "%s\n", edev->name);
}
static DEVICE_ATTR_RO(name);

static ssize_t cable_name_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
						  attr_name);
	int i = cable->cable_index;

	return sprintf(buf, "%s\n",
			extcon_info[cable->edev->supported_cable[i]].name);
}

static ssize_t cable_state_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
						  attr_state);

	int i = cable->cable_index;

	return sprintf(buf, "%d\n",
		extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
}

/**
 * extcon_sync() - Synchronize the state for an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 *
 * Note that this function send a notification in order to synchronize
 * the state and property of an external connector.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_sync(struct extcon_dev *edev, unsigned int id)
{
	char name_buf[120];
	char state_buf[120];
	char *prop_buf;
	char *envp[3];
	int env_offset = 0;
	int length;
	int index;
	int state;
	unsigned long flags;

	if (!edev)
		return -EINVAL;

	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	spin_lock_irqsave(&edev->lock, flags);
	state = !!(edev->state & BIT(index));
	spin_unlock_irqrestore(&edev->lock, flags);

	/*
	 * Call functions in a raw notifier chain for the specific one
	 * external connector.
	 */
	raw_notifier_call_chain(&edev->nh[index], state, edev);

	/*
	 * Call functions in a raw notifier chain for the all supported
	 * external connectors.
	 */
	raw_notifier_call_chain(&edev->nh_all, state, edev);

	spin_lock_irqsave(&edev->lock, flags);
	/* This could be in interrupt handler */
	prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
	if (!prop_buf) {
		/* Unlock early before uevent */
		spin_unlock_irqrestore(&edev->lock, flags);

		dev_err(&edev->dev, "out of memory in extcon_set_state\n");
		kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);

		return -ENOMEM;
	}

	length = name_show(&edev->dev, NULL, prop_buf);
	if (length > 0) {
		if (prop_buf[length - 1] == '\n')
			prop_buf[length - 1] = 0;
		snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
		envp[env_offset++] = name_buf;
	}

	length = state_show(&edev->dev, NULL, prop_buf);
	if (length > 0) {
		if (prop_buf[length - 1] == '\n')
			prop_buf[length - 1] = 0;
		snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
		envp[env_offset++] = state_buf;
	}
	envp[env_offset] = NULL;

	/* Unlock early before uevent */
	spin_unlock_irqrestore(&edev->lock, flags);
	kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
	free_page((unsigned long)prop_buf);

	return 0;
}
EXPORT_SYMBOL_GPL(extcon_sync);

/**
 * extcon_get_state() - Get the state of an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
{
	int index, state;
	unsigned long flags;

	if (!edev)
		return -EINVAL;

	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	spin_lock_irqsave(&edev->lock, flags);
	state = is_extcon_attached(edev, index);
	spin_unlock_irqrestore(&edev->lock, flags);

	return state;
}
EXPORT_SYMBOL_GPL(extcon_get_state);

/**
 * extcon_set_state() - Set the state of an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @state:	the new state of an external connector.
 *		the default semantics is true: attached / false: detached.
 *
 * Note that this function set the state of an external connector without
 * a notification. To synchronize the state of an external connector,
 * have to use extcon_set_state_sync() and extcon_sync().
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_set_state(struct extcon_dev *edev, unsigned int id, bool state)
{
	unsigned long flags;
	int index, ret = 0;

	if (!edev)
		return -EINVAL;

	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	spin_lock_irqsave(&edev->lock, flags);

	/* Check whether the external connector's state is changed. */
	if (!is_extcon_changed(edev, index, state))
		goto out;

	if (check_mutually_exclusive(edev,
		(edev->state & ~BIT(index)) | (state & BIT(index)))) {
		ret = -EPERM;
		goto out;
	}

	/*
	 * Initialize the value of extcon property before setting
	 * the detached state for an external connector.
	 */
	if (!state)
		init_property(edev, id, index);

	/* Update the state for an external connector. */
	if (state)
		edev->state |= BIT(index);
	else
		edev->state &= ~(BIT(index));
out:
	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_set_state);

/**
 * extcon_set_state_sync() - Set the state of an external connector with sync.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @state:	the new state of external connector.
 *		the default semantics is true: attached / false: detached.
 *
 * Note that this function set the state of external connector
 * and synchronize the state by sending a notification.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id, bool state)
{
	int ret;

	ret = extcon_set_state(edev, id, state);
	if (ret < 0)
		return ret;

	return extcon_sync(edev, id);
}
EXPORT_SYMBOL_GPL(extcon_set_state_sync);

/**
 * extcon_get_property() - Get the property value of an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @prop:	the property id indicating an extcon property
 * @prop_val:	the pointer which store the value of extcon property
 *
 * Note that when getting the property value of external connector,
 * the external connector should be attached. If detached state, function
 * return 0 without property value. Also, the each property should be
 * included in the list of supported properties according to extcon type.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_get_property(struct extcon_dev *edev, unsigned int id,
				unsigned int prop,
				union extcon_property_value *prop_val)
{
	struct extcon_cable *cable;
	unsigned long flags;
	int index, ret = 0;

	*prop_val = (union extcon_property_value){0};

	if (!edev)
		return -EINVAL;

	/* Check whether the property is supported or not */
	if (!is_extcon_property_supported(id, prop))
		return -EINVAL;

	/* Find the cable index of external connector by using id */
	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	spin_lock_irqsave(&edev->lock, flags);

	/* Check whether the property is available or not. */
	if (!is_extcon_property_capability(edev, id, index, prop)) {
		spin_unlock_irqrestore(&edev->lock, flags);
		return -EPERM;
	}

	/*
	 * Check whether the external connector is attached.
	 * If external connector is detached, the user can not
	 * get the property value.
	 */
	if (!is_extcon_attached(edev, index)) {
		spin_unlock_irqrestore(&edev->lock, flags);
		return 0;
	}

	cable = &edev->cables[index];

	/* Get the property value according to extcon type */
	switch (prop) {
	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
		*prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
		break;
	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
		*prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
		break;
	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
		*prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
		break;
	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
		*prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
		break;
	default:
		ret = -EINVAL;
		break;
	}

	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_get_property);

/**
 * extcon_set_property() - Set the property value of an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @prop:	the property id indicating an extcon property
 * @prop_val:	the pointer including the new value of extcon property
 *
 * Note that each property should be included in the list of supported
 * properties according to the extcon type.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_set_property(struct extcon_dev *edev, unsigned int id,
				unsigned int prop,
				union extcon_property_value prop_val)
{
	struct extcon_cable *cable;
	unsigned long flags;
	int index, ret = 0;

	if (!edev)
		return -EINVAL;

	/* Check whether the property is supported or not */
	if (!is_extcon_property_supported(id, prop))
		return -EINVAL;

	/* Find the cable index of external connector by using id */
	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	spin_lock_irqsave(&edev->lock, flags);

	/* Check whether the property is available or not. */
	if (!is_extcon_property_capability(edev, id, index, prop)) {
		spin_unlock_irqrestore(&edev->lock, flags);
		return -EPERM;
	}

	cable = &edev->cables[index];

	/* Set the property value according to extcon type */
	switch (prop) {
	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
		cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
		break;
	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
		cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
		break;
	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
		cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
		break;
	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
		cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
		break;
	default:
		ret = -EINVAL;
		break;
	}

	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_set_property);

/**
 * extcon_set_property_sync() - Set property of an external connector with sync.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @prop:	the property id indicating an extcon property
 * @prop_val:	the pointer including the new value of extcon property
 *
 * Note that when setting the property value of external connector,
 * the external connector should be attached. The each property should
 * be included in the list of supported properties according to extcon type.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
				unsigned int prop,
				union extcon_property_value prop_val)
{
	int ret;

	ret = extcon_set_property(edev, id, prop, prop_val);
	if (ret < 0)
		return ret;

	return extcon_sync(edev, id);
}
EXPORT_SYMBOL_GPL(extcon_set_property_sync);

/**
 * extcon_get_property_capability() - Get the capability of the property
 *					for an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @prop:	the property id indicating an extcon property
 *
 * Returns 1 if the property is available or 0 if not available.
 */
int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
					unsigned int prop)
{
	int index;

	if (!edev)
		return -EINVAL;

	/* Check whether the property is supported or not */
	if (!is_extcon_property_supported(id, prop))
		return -EINVAL;

	/* Find the cable index of external connector by using id */
	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	return is_extcon_property_capability(edev, id, index, prop);
}
EXPORT_SYMBOL_GPL(extcon_get_property_capability);

/**
 * extcon_set_property_capability() - Set the capability of the property
 *					for an external connector.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @prop:	the property id indicating an extcon property
 *
 * Note that this function set the capability of the property
 * for an external connector in order to mark the bit in capability
 * bitmap which mean the available state of the property.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
					unsigned int prop)
{
	struct extcon_cable *cable;
	int index, type, ret = 0;

	if (!edev)
		return -EINVAL;

	/* Check whether the property is supported or not. */
	if (!is_extcon_property_supported(id, prop))
		return -EINVAL;

	/* Find the cable index of external connector by using id. */
	index = find_cable_index_by_id(edev, id);
	if (index < 0)
		return index;

	type = get_extcon_type(prop);
	if (type < 0)
		return type;

	cable = &edev->cables[index];

	switch (type) {
	case EXTCON_TYPE_USB:
		__set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
		break;
	case EXTCON_TYPE_CHG:
		__set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
		break;
	case EXTCON_TYPE_JACK:
		__set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
		break;
	case EXTCON_TYPE_DISP:
		__set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_set_property_capability);

/**
 * extcon_get_extcon_dev() - Get the extcon device instance from the name.
 * @extcon_name:	the extcon name provided with extcon_dev_register()
 *
 * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
 * NOTE: This function returns -EPROBE_DEFER so it may only be called from
 * probe() functions.
 */
struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
{
	struct extcon_dev *sd;

	if (!extcon_name)
		return ERR_PTR(-EINVAL);

	mutex_lock(&extcon_dev_list_lock);
	list_for_each_entry(sd, &extcon_dev_list, entry) {
		if (!strcmp(sd->name, extcon_name))
			goto out;
	}
	sd = ERR_PTR(-EPROBE_DEFER);
out:
	mutex_unlock(&extcon_dev_list_lock);
	return sd;
}
EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);

/**
 * extcon_register_notifier() - Register a notifier block to get notified by
 *				any state changes from the extcon.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @nb:		a notifier block to be registered
 *
 * Note that the second parameter given to the callback of nb (val) is
 * the current state of an external connector and the third pameter
 * is the pointer of extcon device.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
			     struct notifier_block *nb)
{
	unsigned long flags;
	int ret, idx;

	if (!edev || !nb)
		return -EINVAL;

	idx = find_cable_index_by_id(edev, id);
	if (idx < 0)
		return idx;

	spin_lock_irqsave(&edev->lock, flags);
	ret = raw_notifier_chain_register(&edev->nh[idx], nb);
	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_register_notifier);

/**
 * extcon_unregister_notifier() - Unregister a notifier block from the extcon.
 * @edev:	the extcon device
 * @id:		the unique id indicating an external connector
 * @nb:		a notifier block to be registered
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
				struct notifier_block *nb)
{
	unsigned long flags;
	int ret, idx;

	if (!edev || !nb)
		return -EINVAL;

	idx = find_cable_index_by_id(edev, id);
	if (idx < 0)
		return idx;

	spin_lock_irqsave(&edev->lock, flags);
	ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_unregister_notifier);

/**
 * extcon_register_notifier_all() - Register a notifier block for all connectors.
 * @edev:	the extcon device
 * @nb:		a notifier block to be registered
 *
 * Note that this function registers a notifier block in order to receive
 * the state change of all supported external connectors from extcon device.
 * And the second parameter given to the callback of nb (val) is
 * the current state and the third pameter is the pointer of extcon device.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_register_notifier_all(struct extcon_dev *edev,
				struct notifier_block *nb)
{
	unsigned long flags;
	int ret;

	if (!edev || !nb)
		return -EINVAL;

	spin_lock_irqsave(&edev->lock, flags);
	ret = raw_notifier_chain_register(&edev->nh_all, nb);
	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_register_notifier_all);

/**
 * extcon_unregister_notifier_all() - Unregister a notifier block from extcon.
 * @edev:	the extcon device
 * @nb:		a notifier block to be registered
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_unregister_notifier_all(struct extcon_dev *edev,
				struct notifier_block *nb)
{
	unsigned long flags;
	int ret;

	if (!edev || !nb)
		return -EINVAL;

	spin_lock_irqsave(&edev->lock, flags);
	ret = raw_notifier_chain_unregister(&edev->nh_all, nb);
	spin_unlock_irqrestore(&edev->lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(extcon_unregister_notifier_all);

static struct attribute *extcon_attrs[] = {
	&dev_attr_state.attr,
	&dev_attr_name.attr,
	NULL,
};
ATTRIBUTE_GROUPS(extcon);

static int create_extcon_class(void)
{
	if (!extcon_class) {
		extcon_class = class_create(THIS_MODULE, "extcon");
		if (IS_ERR(extcon_class))
			return PTR_ERR(extcon_class);
		extcon_class->dev_groups = extcon_groups;
	}

	return 0;
}

static void extcon_dev_release(struct device *dev)
{
}

static const char *muex_name = "mutually_exclusive";
static void dummy_sysfs_dev_release(struct device *dev)
{
}

/*
 * extcon_dev_allocate() - Allocate the memory of extcon device.
 * @supported_cable:	the array of the supported external connectors
 *			ending with EXTCON_NONE.
 *
 * Note that this function allocates the memory for extcon device 
 * and initialize default setting for the extcon device.
 *
 * Returns the pointer memory of allocated extcon_dev if success
 * or ERR_PTR(err) if fail.
 */
struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
{
	struct extcon_dev *edev;

	if (!supported_cable)
		return ERR_PTR(-EINVAL);

	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
	if (!edev)
		return ERR_PTR(-ENOMEM);

	edev->max_supported = 0;
	edev->supported_cable = supported_cable;

	return edev;
}

/*
 * extcon_dev_free() - Free the memory of extcon device.
 * @edev:	the extcon device
 */
void extcon_dev_free(struct extcon_dev *edev)
{
	kfree(edev);
}
EXPORT_SYMBOL_GPL(extcon_dev_free);

/**
 * extcon_dev_register() - Register an new extcon device
 * @edev:	the extcon device to be registered
 *
 * Among the members of edev struct, please set the "user initializing data"
 * do not set the values of "internal data", which are initialized by
 * this function.
 *
 * Note that before calling this funciton, have to allocate the memory
 * of an extcon device by using the extcon_dev_allocate(). And the extcon
 * dev should include the supported_cable information.
 *
 * Returns 0 if success or error number if fail.
 */
int extcon_dev_register(struct extcon_dev *edev)
{
	int ret, index = 0;
	static atomic_t edev_no = ATOMIC_INIT(-1);

	if (!extcon_class) {
		ret = create_extcon_class();
		if (ret < 0)
			return ret;
	}

	if (!edev || !edev->supported_cable)
		return -EINVAL;

	for (; edev->supported_cable[index] != EXTCON_NONE; index++);

	edev->max_supported = index;
	if (index > SUPPORTED_CABLE_MAX) {
		dev_err(&edev->dev,
			"exceed the maximum number of supported cables\n");
		return -EINVAL;
	}

	edev->dev.class = extcon_class;
	edev->dev.release = extcon_dev_release;

	edev->name = dev_name(edev->dev.parent);
	if (IS_ERR_OR_NULL(edev->name)) {
		dev_err(&edev->dev,
			"extcon device name is null\n");
		return -EINVAL;
	}
	dev_set_name(&edev->dev, "extcon%lu",
			(unsigned long)atomic_inc_return(&edev_no));

	if (edev->max_supported) {
		char *str;
		struct extcon_cable *cable;

		edev->cables = kcalloc(edev->max_supported,
				       sizeof(struct extcon_cable),
				       GFP_KERNEL);
		if (!edev->cables) {
			ret = -ENOMEM;
			goto err_sysfs_alloc;
		}
		for (index = 0; index < edev->max_supported; index++) {
			cable = &edev->cables[index];

			str = kasprintf(GFP_KERNEL, "cable.%d", index);
			if (!str) {
				for (index--; index >= 0; index--) {
					cable = &edev->cables[index];
					kfree(cable->attr_g.name);
				}
				ret = -ENOMEM;

				goto err_alloc_cables;
			}

			cable->edev = edev;
			cable->cable_index = index;
			cable->attrs[0] = &cable->attr_name.attr;
			cable->attrs[1] = &cable->attr_state.attr;
			cable->attrs[2] = NULL;
			cable->attr_g.name = str;
			cable->attr_g.attrs = cable->attrs;

			sysfs_attr_init(&cable->attr_name.attr);
			cable->attr_name.attr.name = "name";
			cable->attr_name.attr.mode = 0444;
			cable->attr_name.show = cable_name_show;

			sysfs_attr_init(&cable->attr_state.attr);
			cable->attr_state.attr.name = "state";
			cable->attr_state.attr.mode = 0444;
			cable->attr_state.show = cable_state_show;
		}
	}

	if (edev->max_supported && edev->mutually_exclusive) {
		char *name;

		/* Count the size of mutually_exclusive array */
		for (index = 0; edev->mutually_exclusive[index]; index++)
			;

		edev->attrs_muex = kcalloc(index + 1,
					   sizeof(struct attribute *),
					   GFP_KERNEL);
		if (!edev->attrs_muex) {
			ret = -ENOMEM;
			goto err_muex;
		}

		edev->d_attrs_muex = kcalloc(index,
					     sizeof(struct device_attribute),
					     GFP_KERNEL);
		if (!edev->d_attrs_muex) {
			ret = -ENOMEM;
			kfree(edev->attrs_muex);
			goto err_muex;
		}

		for (index = 0; edev->mutually_exclusive[index]; index++) {
			name = kasprintf(GFP_KERNEL, "0x%x",
					 edev->mutually_exclusive[index]);
			if (!name) {
				for (index--; index >= 0; index--) {
					kfree(edev->d_attrs_muex[index].attr.
					      name);
				}
				kfree(edev->d_attrs_muex);
				kfree(edev->attrs_muex);
				ret = -ENOMEM;
				goto err_muex;
			}
			sysfs_attr_init(&edev->d_attrs_muex[index].attr);
			edev->d_attrs_muex[index].attr.name = name;
			edev->d_attrs_muex[index].attr.mode = 0000;
			edev->attrs_muex[index] = &edev->d_attrs_muex[index]
							.attr;
		}
		edev->attr_g_muex.name = muex_name;
		edev->attr_g_muex.attrs = edev->attrs_muex;

	}

	if (edev->max_supported) {
		edev->extcon_dev_type.groups =
			kcalloc(edev->max_supported + 2,
				sizeof(struct attribute_group *),
				GFP_KERNEL);
		if (!edev->extcon_dev_type.groups) {
			ret = -ENOMEM;
			goto err_alloc_groups;
		}

		edev->extcon_dev_type.name = dev_name(&edev->dev);
		edev->extcon_dev_type.release = dummy_sysfs_dev_release;

		for (index = 0; index < edev->max_supported; index++)
			edev->extcon_dev_type.groups[index] =
				&edev->cables[index].attr_g;
		if (edev->mutually_exclusive)
			edev->extcon_dev_type.groups[index] =
				&edev->attr_g_muex;

		edev->dev.type = &edev->extcon_dev_type;
	}

	spin_lock_init(&edev->lock);
	if (edev->max_supported) {
		edev->nh = kcalloc(edev->max_supported, sizeof(*edev->nh),
				GFP_KERNEL);
		if (!edev->nh) {
			ret = -ENOMEM;
			goto err_alloc_nh;
		}
	}

	for (index = 0; index < edev->max_supported; index++)
		RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);

	RAW_INIT_NOTIFIER_HEAD(&edev->nh_all);

	dev_set_drvdata(&edev->dev, edev);
	edev->state = 0;

	ret = device_register(&edev->dev);
	if (ret) {
		put_device(&edev->dev);
		goto err_dev;
	}

	mutex_lock(&extcon_dev_list_lock);
	list_add(&edev->entry, &extcon_dev_list);
	mutex_unlock(&extcon_dev_list_lock);

	return 0;

err_dev:
	if (edev->max_supported)
		kfree(edev->nh);
err_alloc_nh:
	if (edev->max_supported)
		kfree(edev->extcon_dev_type.groups);
err_alloc_groups:
	if (edev->max_supported && edev->mutually_exclusive) {
		for (index = 0; edev->mutually_exclusive[index]; index++)
			kfree(edev->d_attrs_muex[index].attr.name);
		kfree(edev->d_attrs_muex);
		kfree(edev->attrs_muex);
	}
err_muex:
	for (index = 0; index < edev->max_supported; index++)
		kfree(edev->cables[index].attr_g.name);
err_alloc_cables:
	if (edev->max_supported)
		kfree(edev->cables);
err_sysfs_alloc:
	return ret;
}
EXPORT_SYMBOL_GPL(extcon_dev_register);

/**
 * extcon_dev_unregister() - Unregister the extcon device.
 * @edev:	the extcon device to be unregistered.
 *
 * Note that this does not call kfree(edev) because edev was not allocated
 * by this class.
 */
void extcon_dev_unregister(struct extcon_dev *edev)
{
	int index;

	if (!edev)
		return;

	mutex_lock(&extcon_dev_list_lock);
	list_del(&edev->entry);
	mutex_unlock(&extcon_dev_list_lock);

	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
				dev_name(&edev->dev));
		return;
	}

	device_unregister(&edev->dev);

	if (edev->mutually_exclusive && edev->max_supported) {
		for (index = 0; edev->mutually_exclusive[index];
				index++)
			kfree(edev->d_attrs_muex[index].attr.name);
		kfree(edev->d_attrs_muex);
		kfree(edev->attrs_muex);
	}

	for (index = 0; index < edev->max_supported; index++)
		kfree(edev->cables[index].attr_g.name);

	if (edev->max_supported) {
		kfree(edev->extcon_dev_type.groups);
		kfree(edev->cables);
		kfree(edev->nh);
	}

	put_device(&edev->dev);
}
EXPORT_SYMBOL_GPL(extcon_dev_unregister);

#ifdef CONFIG_OF

/*
 * extcon_find_edev_by_node - Find the extcon device from devicetree.
 * @node	: OF node identifying edev
 *
 * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
 */
struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
{
	struct extcon_dev *edev;

	mutex_lock(&extcon_dev_list_lock);
	list_for_each_entry(edev, &extcon_dev_list, entry)
		if (edev->dev.parent && edev->dev.parent->of_node == node)
			goto out;
	edev = ERR_PTR(-EPROBE_DEFER);
out:
	mutex_unlock(&extcon_dev_list_lock);

	return edev;
}

/*
 * extcon_get_edev_by_phandle - Get the extcon device from devicetree.
 * @dev		: the instance to the given device
 * @index	: the index into list of extcon_dev
 *
 * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
 */
struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
{
	struct device_node *node;
	struct extcon_dev *edev;

	if (!dev)
		return ERR_PTR(-EINVAL);

	if (!dev->of_node) {
		dev_dbg(dev, "device does not have a device node entry\n");
		return ERR_PTR(-EINVAL);
	}

	node = of_parse_phandle(dev->of_node, "extcon", index);
	if (!node) {
		dev_dbg(dev, "failed to get phandle in %pOF node\n",
			dev->of_node);
		return ERR_PTR(-ENODEV);
	}

	edev = extcon_find_edev_by_node(node);
	of_node_put(node);

	return edev;
}

#else

struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
{
	return ERR_PTR(-ENOSYS);
}

struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
{
	return ERR_PTR(-ENOSYS);
}

#endif /* CONFIG_OF */

EXPORT_SYMBOL_GPL(extcon_find_edev_by_node);
EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);

/**
 * extcon_get_edev_name() - Get the name of the extcon device.
 * @edev:	the extcon device
 */
const char *extcon_get_edev_name(struct extcon_dev *edev)
{
	return !edev ? NULL : edev->name;
}
EXPORT_SYMBOL_GPL(extcon_get_edev_name);

static int __init extcon_class_init(void)
{
	return create_extcon_class();
}
module_init(extcon_class_init);

static void __exit extcon_class_exit(void)
{
	class_destroy(extcon_class);
}
module_exit(extcon_class_exit);

MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("External Connector (extcon) framework");
MODULE_LICENSE("GPL v2");