summaryrefslogtreecommitdiff
path: root/drivers/hwmon/adt7470.c
blob: c4b3a4a18670c1a62edef572468c45466551c0f1 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * A hwmon driver for the Analog Devices ADT7470
 * Copyright (C) 2007 IBM
 *
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/kthread.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/util_macros.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x2C, 0x2E, 0x2F, I2C_CLIENT_END };

/* ADT7470 registers */
#define ADT7470_REG_BASE_ADDR			0x20
#define ADT7470_REG_TEMP_BASE_ADDR		0x20
#define ADT7470_REG_TEMP_MAX_ADDR		0x29
#define ADT7470_REG_FAN_BASE_ADDR		0x2A
#define ADT7470_REG_FAN_MAX_ADDR		0x31
#define ADT7470_REG_PWM_BASE_ADDR		0x32
#define ADT7470_REG_PWM_MAX_ADDR		0x35
#define ADT7470_REG_PWM_MAX_BASE_ADDR		0x38
#define ADT7470_REG_PWM_MAX_MAX_ADDR		0x3B
#define ADT7470_REG_CFG				0x40
#define		ADT7470_STRT_MASK		0x01
#define		ADT7470_TEST_MASK		0x02
#define		ADT7470_FSPD_MASK		0x04
#define		ADT7470_T05_STB_MASK		0x80
#define ADT7470_REG_ALARM1			0x41
#define		ADT7470_R1T_ALARM		0x01
#define		ADT7470_R2T_ALARM		0x02
#define		ADT7470_R3T_ALARM		0x04
#define		ADT7470_R4T_ALARM		0x08
#define		ADT7470_R5T_ALARM		0x10
#define		ADT7470_R6T_ALARM		0x20
#define		ADT7470_R7T_ALARM		0x40
#define		ADT7470_OOL_ALARM		0x80
#define ADT7470_REG_ALARM2			0x42
#define		ADT7470_R8T_ALARM		0x01
#define		ADT7470_R9T_ALARM		0x02
#define		ADT7470_R10T_ALARM		0x04
#define		ADT7470_FAN1_ALARM		0x10
#define		ADT7470_FAN2_ALARM		0x20
#define		ADT7470_FAN3_ALARM		0x40
#define		ADT7470_FAN4_ALARM		0x80
#define ADT7470_REG_TEMP_LIMITS_BASE_ADDR	0x44
#define ADT7470_REG_TEMP_LIMITS_MAX_ADDR	0x57
#define ADT7470_REG_FAN_MIN_BASE_ADDR		0x58
#define ADT7470_REG_FAN_MIN_MAX_ADDR		0x5F
#define ADT7470_REG_FAN_MAX_BASE_ADDR		0x60
#define ADT7470_REG_FAN_MAX_MAX_ADDR		0x67
#define ADT7470_REG_PWM_CFG_BASE_ADDR		0x68
#define ADT7470_REG_PWM12_CFG			0x68
#define		ADT7470_PWM2_AUTO_MASK		0x40
#define		ADT7470_PWM1_AUTO_MASK		0x80
#define		ADT7470_PWM_AUTO_MASK		0xC0
#define ADT7470_REG_PWM34_CFG			0x69
#define		ADT7470_PWM3_AUTO_MASK		0x40
#define		ADT7470_PWM4_AUTO_MASK		0x80
#define	ADT7470_REG_PWM_MIN_BASE_ADDR		0x6A
#define ADT7470_REG_PWM_MIN_MAX_ADDR		0x6D
#define ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR	0x6E
#define ADT7470_REG_PWM_TEMP_MIN_MAX_ADDR	0x71
#define ADT7470_REG_CFG_2			0x74
#define ADT7470_REG_ACOUSTICS12			0x75
#define ADT7470_REG_ACOUSTICS34			0x76
#define ADT7470_REG_DEVICE			0x3D
#define ADT7470_REG_VENDOR			0x3E
#define ADT7470_REG_REVISION			0x3F
#define ADT7470_REG_ALARM1_MASK			0x72
#define ADT7470_REG_ALARM2_MASK			0x73
#define ADT7470_REG_PWM_AUTO_TEMP_BASE_ADDR	0x7C
#define ADT7470_REG_PWM_AUTO_TEMP_MAX_ADDR	0x7D
#define ADT7470_REG_MAX_ADDR			0x81

#define ADT7470_TEMP_COUNT	10
#define ADT7470_TEMP_REG(x)	(ADT7470_REG_TEMP_BASE_ADDR + (x))
#define ADT7470_TEMP_MIN_REG(x) (ADT7470_REG_TEMP_LIMITS_BASE_ADDR + ((x) * 2))
#define ADT7470_TEMP_MAX_REG(x) (ADT7470_REG_TEMP_LIMITS_BASE_ADDR + \
				((x) * 2) + 1)

#define ADT7470_FAN_COUNT	4
#define ADT7470_REG_FAN(x)	(ADT7470_REG_FAN_BASE_ADDR + ((x) * 2))
#define ADT7470_REG_FAN_MIN(x)	(ADT7470_REG_FAN_MIN_BASE_ADDR + ((x) * 2))
#define ADT7470_REG_FAN_MAX(x)	(ADT7470_REG_FAN_MAX_BASE_ADDR + ((x) * 2))

#define ADT7470_PWM_COUNT	4
#define ADT7470_REG_PWM(x)	(ADT7470_REG_PWM_BASE_ADDR + (x))
#define ADT7470_REG_PWM_MAX(x)	(ADT7470_REG_PWM_MAX_BASE_ADDR + (x))
#define ADT7470_REG_PWM_MIN(x)	(ADT7470_REG_PWM_MIN_BASE_ADDR + (x))
#define ADT7470_REG_PWM_TMIN(x)	(ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR + (x))
#define ADT7470_REG_PWM_CFG(x)	(ADT7470_REG_PWM_CFG_BASE_ADDR + ((x) / 2))
#define ADT7470_REG_PWM_AUTO_TEMP(x)	(ADT7470_REG_PWM_AUTO_TEMP_BASE_ADDR + \
					((x) / 2))

#define ALARM2(x)		((x) << 8)

#define ADT7470_VENDOR		0x41
#define ADT7470_DEVICE		0x70
/* datasheet only mentions a revision 2 */
#define ADT7470_REVISION	0x02

/* "all temps" according to hwmon sysfs interface spec */
#define ADT7470_PWM_ALL_TEMPS	0x3FF

/* How often do we reread sensors values? (In jiffies) */
#define SENSOR_REFRESH_INTERVAL	(5 * HZ)

/* How often do we reread sensor limit values? (In jiffies) */
#define LIMIT_REFRESH_INTERVAL	(60 * HZ)

/* Wait at least 200ms per sensor for 10 sensors */
#define TEMP_COLLECTION_TIME	2000

/* auto update thing won't fire more than every 2s */
#define AUTO_UPDATE_INTERVAL	2000

/* datasheet says to divide this number by the fan reading to get fan rpm */
#define FAN_PERIOD_TO_RPM(x)	((90000 * 60) / (x))
#define FAN_RPM_TO_PERIOD	FAN_PERIOD_TO_RPM
#define FAN_PERIOD_INVALID	65535
#define FAN_DATA_VALID(x)	((x) && (x) != FAN_PERIOD_INVALID)

/* Config registers 1 and 2 include fields for selecting the PWM frequency */
#define ADT7470_CFG_LF		0x40
#define ADT7470_FREQ_MASK	0x70
#define ADT7470_FREQ_SHIFT	4

struct adt7470_data {
	struct regmap		*regmap;
	struct mutex		lock;
	char			sensors_valid;
	char			limits_valid;
	unsigned long		sensors_last_updated;	/* In jiffies */
	unsigned long		limits_last_updated;	/* In jiffies */

	int			num_temp_sensors;	/* -1 = probe */
	int			temperatures_probed;

	s8			temp[ADT7470_TEMP_COUNT];
	s8			temp_min[ADT7470_TEMP_COUNT];
	s8			temp_max[ADT7470_TEMP_COUNT];
	u16			fan[ADT7470_FAN_COUNT];
	u16			fan_min[ADT7470_FAN_COUNT];
	u16			fan_max[ADT7470_FAN_COUNT];
	u16			alarm;
	u16			alarms_mask;
	u8			force_pwm_max;
	u8			pwm[ADT7470_PWM_COUNT];
	u8			pwm_max[ADT7470_PWM_COUNT];
	u8			pwm_automatic[ADT7470_PWM_COUNT];
	u8			pwm_min[ADT7470_PWM_COUNT];
	s8			pwm_tmin[ADT7470_PWM_COUNT];
	u8			pwm_auto_temp[ADT7470_PWM_COUNT];

	struct task_struct	*auto_update;
	unsigned int		auto_update_interval;
};

/*
 * 16-bit registers on the ADT7470 are low-byte first.  The data sheet says
 * that the low byte must be read before the high byte.
 */
static inline int adt7470_read_word_data(struct adt7470_data *data, unsigned int reg,
					 unsigned int *val)
{
	u8 regval[2];
	int err;

	err = regmap_bulk_read(data->regmap, reg, &regval, 2);
	if (err < 0)
		return err;

	*val = regval[0] | (regval[1] << 8);

	return 0;
}

static inline int adt7470_write_word_data(struct adt7470_data *data, unsigned int reg,
					  unsigned int val)
{
	u8 regval[2];

	regval[0] = val & 0xFF;
	regval[1] = val >> 8;

	return regmap_bulk_write(data->regmap, reg, &regval, 2);
}

/* Probe for temperature sensors.  Assumes lock is held */
static int adt7470_read_temperatures(struct adt7470_data *data)
{
	unsigned long res;
	unsigned int pwm_cfg[2];
	int err;
	int i;
	u8 pwm[ADT7470_FAN_COUNT];

	/* save pwm[1-4] config register */
	err = regmap_read(data->regmap, ADT7470_REG_PWM_CFG(0), &pwm_cfg[0]);
	if (err < 0)
		return err;
	err = regmap_read(data->regmap, ADT7470_REG_PWM_CFG(2), &pwm_cfg[1]);
	if (err < 0)
		return err;

	/* set manual pwm to whatever it is set to now */
	err = regmap_bulk_read(data->regmap, ADT7470_REG_PWM(0), &pwm[0],
			       ADT7470_PWM_COUNT);
	if (err < 0)
		return err;

	/* put pwm in manual mode */
	err = regmap_update_bits(data->regmap, ADT7470_REG_PWM_CFG(0),
				 ADT7470_PWM_AUTO_MASK, 0);
	if (err < 0)
		return err;
	err = regmap_update_bits(data->regmap, ADT7470_REG_PWM_CFG(2),
				 ADT7470_PWM_AUTO_MASK, 0);
	if (err < 0)
		return err;

	/* write pwm control to whatever it was */
	err = regmap_bulk_write(data->regmap, ADT7470_REG_PWM(0), &pwm[0],
				ADT7470_PWM_COUNT);
	if (err < 0)
		return err;

	/* start reading temperature sensors */
	err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
				 ADT7470_T05_STB_MASK, ADT7470_T05_STB_MASK);
	if (err < 0)
		return err;

	/* Delay is 200ms * number of temp sensors. */
	res = msleep_interruptible((data->num_temp_sensors >= 0 ?
				    data->num_temp_sensors * 200 :
				    TEMP_COLLECTION_TIME));

	/* done reading temperature sensors */
	err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
				 ADT7470_T05_STB_MASK, 0);
	if (err < 0)
		return err;

	/* restore pwm[1-4] config registers */
	err = regmap_write(data->regmap, ADT7470_REG_PWM_CFG(0), pwm_cfg[0]);
	if (err < 0)
		return err;
	err = regmap_write(data->regmap, ADT7470_REG_PWM_CFG(2), pwm_cfg[1]);
	if (err < 0)
		return err;

	if (res)
		return -EAGAIN;

	/* Only count fans if we have to */
	if (data->num_temp_sensors >= 0)
		return 0;

	err = regmap_bulk_read(data->regmap, ADT7470_TEMP_REG(0), &data->temp[0],
			       ADT7470_TEMP_COUNT);
	if (err < 0)
		return err;
	for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
		if (data->temp[i])
			data->num_temp_sensors = i + 1;
	}
	data->temperatures_probed = 1;
	return 0;
}

static int adt7470_update_thread(void *p)
{
	struct i2c_client *client = p;
	struct adt7470_data *data = i2c_get_clientdata(client);

	while (!kthread_should_stop()) {
		mutex_lock(&data->lock);
		adt7470_read_temperatures(data);
		mutex_unlock(&data->lock);

		if (kthread_should_stop())
			break;

		schedule_timeout_interruptible(msecs_to_jiffies(data->auto_update_interval));
	}

	return 0;
}

static int adt7470_update_sensors(struct adt7470_data *data)
{
	unsigned int val;
	int err;
	int i;

	if (!data->temperatures_probed)
		err = adt7470_read_temperatures(data);
	else
		err = regmap_bulk_read(data->regmap, ADT7470_TEMP_REG(0), &data->temp[0],
				       ADT7470_TEMP_COUNT);
	if (err < 0)
		return err;

	for (i = 0; i < ADT7470_FAN_COUNT; i++) {
		err = adt7470_read_word_data(data, ADT7470_REG_FAN(i), &val);
		if (err < 0)
			return err;
		data->fan[i] =	val;
	}

	err = regmap_bulk_read(data->regmap, ADT7470_REG_PWM(0), &data->pwm[0], ADT7470_PWM_COUNT);
	if (err < 0)
		return err;

	for (i = 0; i < ADT7470_PWM_COUNT; i++) {
		unsigned int mask;

		if (i % 2)
			mask = ADT7470_PWM2_AUTO_MASK;
		else
			mask = ADT7470_PWM1_AUTO_MASK;

		err = regmap_read(data->regmap, ADT7470_REG_PWM_CFG(i), &val);
		if (err < 0)
			return err;
		data->pwm_automatic[i] = !!(val & mask);

		err = regmap_read(data->regmap, ADT7470_REG_PWM_AUTO_TEMP(i), &val);
		if (err < 0)
			return err;
		if (!(i % 2))
			data->pwm_auto_temp[i] = val >> 4;
		else
			data->pwm_auto_temp[i] = val & 0xF;
	}

	err = regmap_read(data->regmap, ADT7470_REG_CFG, &val);
	if (err < 0)
		return err;
	data->force_pwm_max = !!(val & ADT7470_FSPD_MASK);

	err = regmap_read(data->regmap, ADT7470_REG_ALARM1, &val);
	if (err < 0)
		return err;
	data->alarm = val;
	if (data->alarm & ADT7470_OOL_ALARM) {
		err = regmap_read(data->regmap, ADT7470_REG_ALARM2, &val);
		if (err < 0)
			return err;
		data->alarm |= ALARM2(val);
	}

	err = adt7470_read_word_data(data, ADT7470_REG_ALARM1_MASK, &val);
	if (err < 0)
		return err;
	data->alarms_mask = val;

	return 0;
}

static int adt7470_update_limits(struct adt7470_data *data)
{
	unsigned int val;
	int err;
	int i;

	for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
		err = regmap_read(data->regmap, ADT7470_TEMP_MIN_REG(i), &val);
		if (err < 0)
			return err;
		data->temp_min[i] = (s8)val;
		err = regmap_read(data->regmap, ADT7470_TEMP_MAX_REG(i), &val);
		if (err < 0)
			return err;
		data->temp_max[i] = (s8)val;
	}

	for (i = 0; i < ADT7470_FAN_COUNT; i++) {
		err = adt7470_read_word_data(data, ADT7470_REG_FAN_MIN(i), &val);
		if (err < 0)
			return err;
		data->fan_min[i] = val;
		err = adt7470_read_word_data(data, ADT7470_REG_FAN_MAX(i), &val);
		if (err < 0)
			return err;
		data->fan_max[i] = val;
	}

	for (i = 0; i < ADT7470_PWM_COUNT; i++) {
		err = regmap_read(data->regmap, ADT7470_REG_PWM_MAX(i), &val);
		if (err < 0)
			return err;
		data->pwm_max[i] = val;
		err = regmap_read(data->regmap, ADT7470_REG_PWM_MIN(i), &val);
		if (err < 0)
			return err;
		data->pwm_min[i] = val;
		err = regmap_read(data->regmap, ADT7470_REG_PWM_TMIN(i), &val);
		if (err < 0)
			return err;
		data->pwm_tmin[i] = (s8)val;
	}

	return 0;
}

static struct adt7470_data *adt7470_update_device(struct device *dev)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	unsigned long local_jiffies = jiffies;
	int need_sensors = 1;
	int need_limits = 1;
	int err;

	/*
	 * Figure out if we need to update the shadow registers.
	 * Lockless means that we may occasionally report out of
	 * date data.
	 */
	if (time_before(local_jiffies, data->sensors_last_updated +
			SENSOR_REFRESH_INTERVAL) &&
	    data->sensors_valid)
		need_sensors = 0;

	if (time_before(local_jiffies, data->limits_last_updated +
			LIMIT_REFRESH_INTERVAL) &&
	    data->limits_valid)
		need_limits = 0;

	if (!need_sensors && !need_limits)
		return data;

	mutex_lock(&data->lock);
	if (need_sensors) {
		err = adt7470_update_sensors(data);
		if (err < 0)
			goto out;
		data->sensors_last_updated = local_jiffies;
		data->sensors_valid = 1;
	}

	if (need_limits) {
		err = adt7470_update_limits(data);
		if (err < 0)
			goto out;
		data->limits_last_updated = local_jiffies;
		data->limits_valid = 1;
	}
out:
	mutex_unlock(&data->lock);

	return err < 0 ? ERR_PTR(err) : data;
}

static ssize_t auto_update_interval_show(struct device *dev,
					 struct device_attribute *devattr,
					 char *buf)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", data->auto_update_interval);
}

static ssize_t auto_update_interval_store(struct device *dev,
					  struct device_attribute *devattr,
					  const char *buf, size_t count)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	long temp;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	temp = clamp_val(temp, 0, 60000);

	mutex_lock(&data->lock);
	data->auto_update_interval = temp;
	mutex_unlock(&data->lock);

	return count;
}

static ssize_t num_temp_sensors_show(struct device *dev,
				     struct device_attribute *devattr,
				     char *buf)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", data->num_temp_sensors);
}

static ssize_t num_temp_sensors_store(struct device *dev,
				      struct device_attribute *devattr,
				      const char *buf, size_t count)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	long temp;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	temp = clamp_val(temp, -1, 10);

	mutex_lock(&data->lock);
	data->num_temp_sensors = temp;
	if (temp < 0)
		data->temperatures_probed = 0;
	mutex_unlock(&data->lock);

	return count;
}

static int adt7470_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	switch (attr) {
	case hwmon_temp_input:
		*val = 1000 * data->temp[channel];
		break;
	case hwmon_temp_min:
		*val = 1000 * data->temp_min[channel];
		break;
	case hwmon_temp_max:
		*val = 1000 * data->temp_max[channel];
		break;
	case hwmon_temp_alarm:
		*val = !!(data->alarm & channel);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int adt7470_temp_write(struct device *dev, u32 attr, int channel, long val)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	int err;

	val = clamp_val(val, -128000, 127000);
	val = DIV_ROUND_CLOSEST(val, 1000);

	switch (attr) {
	case hwmon_temp_min:
		mutex_lock(&data->lock);
		data->temp_min[channel] = val;
		err = regmap_write(data->regmap, ADT7470_TEMP_MIN_REG(channel), val);
		mutex_unlock(&data->lock);
		break;
	case hwmon_temp_max:
		mutex_lock(&data->lock);
		data->temp_max[channel] = val;
		err = regmap_write(data->regmap, ADT7470_TEMP_MAX_REG(channel), val);
		mutex_unlock(&data->lock);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return err;
}

static ssize_t alarm_mask_show(struct device *dev,
			       struct device_attribute *devattr, char *buf)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%x\n", data->alarms_mask);
}

static ssize_t alarm_mask_store(struct device *dev,
				struct device_attribute *devattr,
				const char *buf, size_t count)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	long mask;
	int err;

	if (kstrtoul(buf, 0, &mask))
		return -EINVAL;

	if (mask & ~0xffff)
		return -EINVAL;

	mutex_lock(&data->lock);
	data->alarms_mask = mask;
	err = adt7470_write_word_data(data, ADT7470_REG_ALARM1_MASK, mask);
	mutex_unlock(&data->lock);

	return err < 0 ? err : count;
}

static int adt7470_fan_read(struct device *dev, u32 attr, int channel, long *val)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	switch (attr) {
	case hwmon_fan_input:
		if (FAN_DATA_VALID(data->fan[channel]))
			*val = FAN_PERIOD_TO_RPM(data->fan[channel]);
		else
			*val = 0;
		break;
	case hwmon_fan_min:
		if (FAN_DATA_VALID(data->fan_min[channel]))
			*val = FAN_PERIOD_TO_RPM(data->fan_min[channel]);
		else
			*val = 0;
		break;
	case hwmon_fan_max:
		if (FAN_DATA_VALID(data->fan_max[channel]))
			*val = FAN_PERIOD_TO_RPM(data->fan_max[channel]);
		else
			*val = 0;
		break;
	case hwmon_fan_alarm:
		*val = !!(data->alarm & (1 << (12 + channel)));
		break;
	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	int err;

	if (val <= 0)
		return -EINVAL;

	val = FAN_RPM_TO_PERIOD(val);
	val = clamp_val(val, 1, 65534);

	switch (attr) {
	case hwmon_fan_min:
		mutex_lock(&data->lock);
		data->fan_min[channel] = val;
		err = adt7470_write_word_data(data, ADT7470_REG_FAN_MIN(channel), val);
		mutex_unlock(&data->lock);
		break;
	case hwmon_fan_max:
		mutex_lock(&data->lock);
		data->fan_max[channel] = val;
		err = adt7470_write_word_data(data, ADT7470_REG_FAN_MAX(channel), val);
		mutex_unlock(&data->lock);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return err;
}

static ssize_t force_pwm_max_show(struct device *dev,
				  struct device_attribute *devattr, char *buf)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", data->force_pwm_max);
}

static ssize_t force_pwm_max_store(struct device *dev,
				   struct device_attribute *devattr,
				   const char *buf, size_t count)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	long temp;
	int err;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	mutex_lock(&data->lock);
	data->force_pwm_max = temp;
	err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
				 ADT7470_FSPD_MASK,
				 temp ? ADT7470_FSPD_MASK : 0);
	mutex_unlock(&data->lock);

	return err < 0 ? err : count;
}

/* These are the valid PWM frequencies to the nearest Hz */
static const int adt7470_freq_map[] = {
	11, 15, 22, 29, 35, 44, 59, 88, 1400, 22500
};

static int pwm1_freq_get(struct device *dev)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	unsigned int cfg_reg_1, cfg_reg_2;
	int index;
	int err;

	mutex_lock(&data->lock);
	err = regmap_read(data->regmap, ADT7470_REG_CFG, &cfg_reg_1);
	if (err < 0)
		goto out;
	err = regmap_read(data->regmap, ADT7470_REG_CFG_2, &cfg_reg_2);
	if (err < 0)
		goto out;
	mutex_unlock(&data->lock);

	index = (cfg_reg_2 & ADT7470_FREQ_MASK) >> ADT7470_FREQ_SHIFT;
	if (!(cfg_reg_1 & ADT7470_CFG_LF))
		index += 8;
	if (index >= ARRAY_SIZE(adt7470_freq_map))
		index = ARRAY_SIZE(adt7470_freq_map) - 1;

	return adt7470_freq_map[index];

out:
	mutex_unlock(&data->lock);
	return err;
}

static int adt7470_pwm_read(struct device *dev, u32 attr, int channel, long *val)
{
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	switch (attr) {
	case hwmon_pwm_input:
		*val = data->pwm[channel];
		break;
	case hwmon_pwm_enable:
		*val = 1 + data->pwm_automatic[channel];
		break;
	case hwmon_pwm_freq:
		*val = pwm1_freq_get(dev);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int pwm1_freq_set(struct device *dev, long freq)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	unsigned int low_freq = ADT7470_CFG_LF;
	int index;
	int err;

	/* Round the user value given to the closest available frequency */
	index = find_closest(freq, adt7470_freq_map,
			     ARRAY_SIZE(adt7470_freq_map));

	if (index >= 8) {
		index -= 8;
		low_freq = 0;
	}

	mutex_lock(&data->lock);
	/* Configuration Register 1 */
	err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
				 ADT7470_CFG_LF, low_freq);
	if (err < 0)
		goto out;

	/* Configuration Register 2 */
	err = regmap_update_bits(data->regmap, ADT7470_REG_CFG_2,
				 ADT7470_FREQ_MASK,
				 index << ADT7470_FREQ_SHIFT);
out:
	mutex_unlock(&data->lock);

	return err;
}

static int adt7470_pwm_write(struct device *dev, u32 attr, int channel, long val)
{
	struct adt7470_data *data = dev_get_drvdata(dev);
	unsigned int pwm_auto_reg_mask;
	int err;

	switch (attr) {
	case hwmon_pwm_input:
		val = clamp_val(val, 0, 255);
		mutex_lock(&data->lock);
		data->pwm[channel] = val;
		err = regmap_write(data->regmap, ADT7470_REG_PWM(channel),
				   data->pwm[channel]);
		mutex_unlock(&data->lock);
		break;
	case hwmon_pwm_enable:
		if (channel % 2)
			pwm_auto_reg_mask = ADT7470_PWM2_AUTO_MASK;
		else
			pwm_auto_reg_mask = ADT7470_PWM1_AUTO_MASK;

		if (val != 2 && val != 1)
			return -EINVAL;
		val--;

		mutex_lock(&data->lock);
		data->pwm_automatic[channel] = val;
		err = regmap_update_bits(data->regmap, ADT7470_REG_PWM_CFG(channel),
					 pwm_auto_reg_mask,
					 val ? pwm_auto_reg_mask : 0);
		mutex_unlock(&data->lock);
		break;
	case hwmon_pwm_freq:
		err = pwm1_freq_set(dev, val);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return err;
}

static ssize_t pwm_max_show(struct device *dev,
			    struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", data->pwm_max[attr->index]);
}

static ssize_t pwm_max_store(struct device *dev,
			     struct device_attribute *devattr,
			     const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = dev_get_drvdata(dev);
	long temp;
	int err;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	temp = clamp_val(temp, 0, 255);

	mutex_lock(&data->lock);
	data->pwm_max[attr->index] = temp;
	err = regmap_write(data->regmap, ADT7470_REG_PWM_MAX(attr->index),
			   temp);
	mutex_unlock(&data->lock);

	return err < 0 ? err : count;
}

static ssize_t pwm_min_show(struct device *dev,
			    struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", data->pwm_min[attr->index]);
}

static ssize_t pwm_min_store(struct device *dev,
			     struct device_attribute *devattr,
			     const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = dev_get_drvdata(dev);
	long temp;
	int err;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	temp = clamp_val(temp, 0, 255);

	mutex_lock(&data->lock);
	data->pwm_min[attr->index] = temp;
	err = regmap_write(data->regmap, ADT7470_REG_PWM_MIN(attr->index),
			   temp);
	mutex_unlock(&data->lock);

	return err < 0 ? err : count;
}

static ssize_t pwm_tmax_show(struct device *dev,
			     struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	/* the datasheet says that tmax = tmin + 20C */
	return sprintf(buf, "%d\n", 1000 * (20 + data->pwm_tmin[attr->index]));
}

static ssize_t pwm_tmin_show(struct device *dev,
			     struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = adt7470_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", 1000 * data->pwm_tmin[attr->index]);
}

static ssize_t pwm_tmin_store(struct device *dev,
			      struct device_attribute *devattr,
			      const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = dev_get_drvdata(dev);
	long temp;
	int err;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	temp = clamp_val(temp, -128000, 127000);
	temp = DIV_ROUND_CLOSEST(temp, 1000);

	mutex_lock(&data->lock);
	data->pwm_tmin[attr->index] = temp;
	err = regmap_write(data->regmap, ADT7470_REG_PWM_TMIN(attr->index),
			   temp);
	mutex_unlock(&data->lock);

	return err < 0 ? err : count;
}

static ssize_t pwm_auto_temp_show(struct device *dev,
				  struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = adt7470_update_device(dev);
	u8 ctrl;

	if (IS_ERR(data))
		return PTR_ERR(data);

	ctrl = data->pwm_auto_temp[attr->index];
	if (ctrl)
		return sprintf(buf, "%d\n", 1 << (ctrl - 1));
	else
		return sprintf(buf, "%d\n", ADT7470_PWM_ALL_TEMPS);
}

static int cvt_auto_temp(int input)
{
	if (input == ADT7470_PWM_ALL_TEMPS)
		return 0;
	if (input < 1 || !is_power_of_2(input))
		return -EINVAL;
	return ilog2(input) + 1;
}

static ssize_t pwm_auto_temp_store(struct device *dev,
				   struct device_attribute *devattr,
				   const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adt7470_data *data = dev_get_drvdata(dev);
	int pwm_auto_reg = ADT7470_REG_PWM_AUTO_TEMP(attr->index);
	unsigned int mask, val;
	long temp;
	int err;

	if (kstrtol(buf, 10, &temp))
		return -EINVAL;

	temp = cvt_auto_temp(temp);
	if (temp < 0)
		return temp;

	mutex_lock(&data->lock);
	data->pwm_automatic[attr->index] = temp;

	if (!(attr->index % 2)) {
		mask = 0xF0;
		val = (temp << 4) & 0xF0;
	} else {
		mask = 0x0F;
		val = temp & 0x0F;
	}

	err = regmap_update_bits(data->regmap, pwm_auto_reg, mask, val);
	mutex_unlock(&data->lock);

	return err < 0 ? err : count;
}

static DEVICE_ATTR_RW(alarm_mask);
static DEVICE_ATTR_RW(num_temp_sensors);
static DEVICE_ATTR_RW(auto_update_interval);

static SENSOR_DEVICE_ATTR_RW(force_pwm_max, force_pwm_max, 0);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_pwm, pwm_min, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point1_pwm, pwm_min, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point1_pwm, pwm_min, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_point1_pwm, pwm_min, 3);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_pwm, pwm_max, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point2_pwm, pwm_max, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point2_pwm, pwm_max, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_point2_pwm, pwm_max, 3);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_temp, pwm_tmin, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point1_temp, pwm_tmin, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point1_temp, pwm_tmin, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_point1_temp, pwm_tmin, 3);

static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point2_temp, pwm_tmax, 0);
static SENSOR_DEVICE_ATTR_RO(pwm2_auto_point2_temp, pwm_tmax, 1);
static SENSOR_DEVICE_ATTR_RO(pwm3_auto_point2_temp, pwm_tmax, 2);
static SENSOR_DEVICE_ATTR_RO(pwm4_auto_point2_temp, pwm_tmax, 3);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_channels_temp, pwm_auto_temp, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_channels_temp, pwm_auto_temp, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_channels_temp, pwm_auto_temp, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_channels_temp, pwm_auto_temp, 3);

static struct attribute *adt7470_attrs[] = {
	&dev_attr_alarm_mask.attr,
	&dev_attr_num_temp_sensors.attr,
	&dev_attr_auto_update_interval.attr,
	&sensor_dev_attr_force_pwm_max.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm3_auto_point1_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm4_auto_point1_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm3_auto_point2_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm4_auto_point2_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
	&sensor_dev_attr_pwm2_auto_point1_temp.dev_attr.attr,
	&sensor_dev_attr_pwm3_auto_point1_temp.dev_attr.attr,
	&sensor_dev_attr_pwm4_auto_point1_temp.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
	&sensor_dev_attr_pwm2_auto_point2_temp.dev_attr.attr,
	&sensor_dev_attr_pwm3_auto_point2_temp.dev_attr.attr,
	&sensor_dev_attr_pwm4_auto_point2_temp.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
	&sensor_dev_attr_pwm3_auto_channels_temp.dev_attr.attr,
	&sensor_dev_attr_pwm4_auto_channels_temp.dev_attr.attr,
	NULL
};

ATTRIBUTE_GROUPS(adt7470);

static int adt7470_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
			int channel, long *val)
{
	switch (type) {
	case hwmon_temp:
		return adt7470_temp_read(dev, attr, channel, val);
	case hwmon_fan:
		return adt7470_fan_read(dev, attr, channel, val);
	case hwmon_pwm:
		return adt7470_pwm_read(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7470_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
			 int channel, long val)
{
	switch (type) {
	case hwmon_temp:
		return adt7470_temp_write(dev, attr, channel, val);
	case hwmon_fan:
		return adt7470_fan_write(dev, attr, channel, val);
	case hwmon_pwm:
		return adt7470_pwm_write(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static umode_t adt7470_is_visible(const void *_data, enum hwmon_sensor_types type,
				  u32 attr, int channel)
{
	umode_t mode = 0;

	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp:
		case hwmon_temp_alarm:
			mode = 0444;
			break;
		case hwmon_temp_min:
		case hwmon_temp_max:
			mode = 0644;
			break;
		default:
			break;
		}
		break;
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_input:
		case hwmon_fan_alarm:
			mode = 0444;
			break;
		case hwmon_fan_min:
		case hwmon_fan_max:
			mode = 0644;
			break;
		default:
			break;
		}
		break;
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
		case hwmon_pwm_enable:
			mode = 0644;
			break;
		case hwmon_pwm_freq:
			if (channel == 0)
				mode = 0644;
			else
				mode = 0;
			break;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return mode;
}

static const struct hwmon_ops adt7470_hwmon_ops = {
	.is_visible = adt7470_is_visible,
	.read = adt7470_read,
	.write = adt7470_write,
};

static const struct hwmon_channel_info * const adt7470_info[] = {
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM),
	HWMON_CHANNEL_INFO(fan,
			   HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM,
			   HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM,
			   HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM,
			   HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM),
	HWMON_CHANNEL_INFO(pwm,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE | HWMON_PWM_FREQ,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
	NULL
};

static const struct hwmon_chip_info adt7470_chip_info = {
	.ops = &adt7470_hwmon_ops,
	.info = adt7470_info,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int adt7470_detect(struct i2c_client *client,
			  struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	int vendor, device, revision;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -ENODEV;

	vendor = i2c_smbus_read_byte_data(client, ADT7470_REG_VENDOR);
	if (vendor != ADT7470_VENDOR)
		return -ENODEV;

	device = i2c_smbus_read_byte_data(client, ADT7470_REG_DEVICE);
	if (device != ADT7470_DEVICE)
		return -ENODEV;

	revision = i2c_smbus_read_byte_data(client, ADT7470_REG_REVISION);
	if (revision != ADT7470_REVISION)
		return -ENODEV;

	strscpy(info->type, "adt7470", I2C_NAME_SIZE);

	return 0;
}

static const struct regmap_config adt7470_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.use_single_read = true,
	.use_single_write = true,
};

static int adt7470_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct adt7470_data *data;
	struct device *hwmon_dev;
	int err;

	data = devm_kzalloc(dev, sizeof(struct adt7470_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->num_temp_sensors = -1;
	data->auto_update_interval = AUTO_UPDATE_INTERVAL;
	data->regmap = devm_regmap_init_i2c(client, &adt7470_regmap_config);
	if (IS_ERR(data->regmap))
		return PTR_ERR(data->regmap);

	i2c_set_clientdata(client, data);
	mutex_init(&data->lock);

	dev_info(&client->dev, "%s chip found\n", client->name);

	/* Initialize the ADT7470 chip */
	err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
				 ADT7470_STRT_MASK | ADT7470_TEST_MASK,
				 ADT7470_STRT_MASK | ADT7470_TEST_MASK);
	if (err < 0)
		return err;

	/* Register sysfs hooks */
	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
							 &adt7470_chip_info,
							 adt7470_groups);

	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

	data->auto_update = kthread_run(adt7470_update_thread, client, "%s",
					dev_name(hwmon_dev));
	if (IS_ERR(data->auto_update))
		return PTR_ERR(data->auto_update);

	return 0;
}

static void adt7470_remove(struct i2c_client *client)
{
	struct adt7470_data *data = i2c_get_clientdata(client);

	kthread_stop(data->auto_update);
}

static const struct i2c_device_id adt7470_id[] = {
	{ "adt7470", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, adt7470_id);

static struct i2c_driver adt7470_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "adt7470",
	},
	.probe		= adt7470_probe,
	.remove		= adt7470_remove,
	.id_table	= adt7470_id,
	.detect		= adt7470_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(adt7470_driver);

MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
MODULE_DESCRIPTION("ADT7470 driver");
MODULE_LICENSE("GPL");