summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/lm90.c
blob: 22efae34c2f62d40a0c93a3279337da0848b68be (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
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
/*
 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2010  Jean Delvare <khali@linux-fr.org>
 *
 * Based on the lm83 driver. The LM90 is a sensor chip made by National
 * Semiconductor. It reports up to two temperatures (its own plus up to
 * one external one) with a 0.125 deg resolution (1 deg for local
 * temperature) and a 3-4 deg accuracy.
 *
 * This driver also supports the LM89 and LM99, two other sensor chips
 * made by National Semiconductor. Both have an increased remote
 * temperature measurement accuracy (1 degree), and the LM99
 * additionally shifts remote temperatures (measured and limits) by 16
 * degrees, which allows for higher temperatures measurement.
 * Note that there is no way to differentiate between both chips.
 * When device is auto-detected, the driver will assume an LM99.
 *
 * This driver also supports the LM86, another sensor chip made by
 * National Semiconductor. It is exactly similar to the LM90 except it
 * has a higher accuracy.
 *
 * This driver also supports the ADM1032, a sensor chip made by Analog
 * Devices. That chip is similar to the LM90, with a few differences
 * that are not handled by this driver. Among others, it has a higher
 * accuracy than the LM90, much like the LM86 does.
 *
 * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
 * chips made by Maxim. These chips are similar to the LM86.
 * Note that there is no easy way to differentiate between the three
 * variants. We use the device address to detect MAX6659, which will result
 * in a detection as max6657 if it is on address 0x4c. The extra address
 * and features of the MAX6659 are only supported if the chip is configured
 * explicitly as max6659, or if its address is not 0x4c.
 * These chips lack the remote temperature offset feature.
 *
 * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
 * MAX6692 chips made by Maxim.  These are again similar to the LM86,
 * but they use unsigned temperature values and can report temperatures
 * from 0 to 145 degrees.
 *
 * This driver also supports the MAX6680 and MAX6681, two other sensor
 * chips made by Maxim. These are quite similar to the other Maxim
 * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
 * be treated identically.
 *
 * This driver also supports the MAX6695 and MAX6696, two other sensor
 * chips made by Maxim. These are also quite similar to other Maxim
 * chips, but support three temperature sensors instead of two. MAX6695
 * and MAX6696 only differ in the pinout so they can be treated identically.
 *
 * This driver also supports ADT7461 and ADT7461A from Analog Devices as well as
 * NCT1008 from ON Semiconductor. The chips are supported in both compatibility
 * and extended mode. They are mostly compatible with LM90 except for a data
 * format difference for the temperature value registers.
 *
 * This driver also supports the SA56004 from Philips. This device is
 * pin-compatible with the LM86, the ED/EDP parts are also address-compatible.
 *
 * Since the LM90 was the first chipset supported by this driver, most
 * comments will refer to this chipset, but are actually general and
 * concern all supported chipsets, unless mentioned otherwise.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>

/*
 * Addresses to scan
 * Address is fully defined internally and cannot be changed except for
 * MAX6659, MAX6680 and MAX6681.
 * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
 * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
 * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
 * have address 0x4d.
 * MAX6647 has address 0x4e.
 * MAX6659 can have address 0x4c, 0x4d or 0x4e.
 * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
 * 0x4c, 0x4d or 0x4e.
 * SA56004 can have address 0x48 through 0x4F.
 */

static const unsigned short normal_i2c[] = {
	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };

enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
	max6646, w83l771, max6696, sa56004 };

/*
 * The LM90 registers
 */

#define LM90_REG_R_MAN_ID		0xFE
#define LM90_REG_R_CHIP_ID		0xFF
#define LM90_REG_R_CONFIG1		0x03
#define LM90_REG_W_CONFIG1		0x09
#define LM90_REG_R_CONFIG2		0xBF
#define LM90_REG_W_CONFIG2		0xBF
#define LM90_REG_R_CONVRATE		0x04
#define LM90_REG_W_CONVRATE		0x0A
#define LM90_REG_R_STATUS		0x02
#define LM90_REG_R_LOCAL_TEMP		0x00
#define LM90_REG_R_LOCAL_HIGH		0x05
#define LM90_REG_W_LOCAL_HIGH		0x0B
#define LM90_REG_R_LOCAL_LOW		0x06
#define LM90_REG_W_LOCAL_LOW		0x0C
#define LM90_REG_R_LOCAL_CRIT		0x20
#define LM90_REG_W_LOCAL_CRIT		0x20
#define LM90_REG_R_REMOTE_TEMPH		0x01
#define LM90_REG_R_REMOTE_TEMPL		0x10
#define LM90_REG_R_REMOTE_OFFSH		0x11
#define LM90_REG_W_REMOTE_OFFSH		0x11
#define LM90_REG_R_REMOTE_OFFSL		0x12
#define LM90_REG_W_REMOTE_OFFSL		0x12
#define LM90_REG_R_REMOTE_HIGHH		0x07
#define LM90_REG_W_REMOTE_HIGHH		0x0D
#define LM90_REG_R_REMOTE_HIGHL		0x13
#define LM90_REG_W_REMOTE_HIGHL		0x13
#define LM90_REG_R_REMOTE_LOWH		0x08
#define LM90_REG_W_REMOTE_LOWH		0x0E
#define LM90_REG_R_REMOTE_LOWL		0x14
#define LM90_REG_W_REMOTE_LOWL		0x14
#define LM90_REG_R_REMOTE_CRIT		0x19
#define LM90_REG_W_REMOTE_CRIT		0x19
#define LM90_REG_R_TCRIT_HYST		0x21
#define LM90_REG_W_TCRIT_HYST		0x21

/* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */

#define MAX6657_REG_R_LOCAL_TEMPL	0x11
#define MAX6696_REG_R_STATUS2		0x12
#define MAX6659_REG_R_REMOTE_EMERG	0x16
#define MAX6659_REG_W_REMOTE_EMERG	0x16
#define MAX6659_REG_R_LOCAL_EMERG	0x17
#define MAX6659_REG_W_LOCAL_EMERG	0x17

/*  SA56004 registers */

#define SA56004_REG_R_LOCAL_TEMPL 0x22

#define LM90_DEF_CONVRATE_RVAL	6	/* Def conversion rate register value */
#define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */

/*
 * Device flags
 */
#define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
/* Device features */
#define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
#define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
#define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
#define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
#define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
#define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id lm90_id[] = {
	{ "adm1032", adm1032 },
	{ "adt7461", adt7461 },
	{ "adt7461a", adt7461 },
	{ "lm90", lm90 },
	{ "lm86", lm86 },
	{ "lm89", lm86 },
	{ "lm99", lm99 },
	{ "max6646", max6646 },
	{ "max6647", max6646 },
	{ "max6649", max6646 },
	{ "max6657", max6657 },
	{ "max6658", max6657 },
	{ "max6659", max6659 },
	{ "max6680", max6680 },
	{ "max6681", max6680 },
	{ "max6695", max6696 },
	{ "max6696", max6696 },
	{ "nct1008", adt7461 },
	{ "w83l771", w83l771 },
	{ "sa56004", sa56004 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm90_id);

/*
 * chip type specific parameters
 */
struct lm90_params {
	u32 flags;		/* Capabilities */
	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
				/* Upper 8 bits for max6695/96 */
	u8 max_convrate;	/* Maximum conversion rate register value */
	u8 reg_local_ext;	/* Extended local temp register (optional) */
};

static const struct lm90_params lm90_params[] = {
	[adm1032] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
		  | LM90_HAVE_BROKEN_ALERT,
		.alert_alarms = 0x7c,
		.max_convrate = 10,
	},
	[adt7461] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
		  | LM90_HAVE_BROKEN_ALERT,
		.alert_alarms = 0x7c,
		.max_convrate = 10,
	},
	[lm86] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
		.alert_alarms = 0x7b,
		.max_convrate = 9,
	},
	[lm90] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
		.alert_alarms = 0x7b,
		.max_convrate = 9,
	},
	[lm99] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
		.alert_alarms = 0x7b,
		.max_convrate = 9,
	},
	[max6646] = {
		.alert_alarms = 0x7c,
		.max_convrate = 6,
		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
	},
	[max6657] = {
		.alert_alarms = 0x7c,
		.max_convrate = 8,
		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
	},
	[max6659] = {
		.flags = LM90_HAVE_EMERGENCY,
		.alert_alarms = 0x7c,
		.max_convrate = 8,
		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
	},
	[max6680] = {
		.flags = LM90_HAVE_OFFSET,
		.alert_alarms = 0x7c,
		.max_convrate = 7,
	},
	[max6696] = {
		.flags = LM90_HAVE_EMERGENCY
		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
		.alert_alarms = 0x187c,
		.max_convrate = 6,
		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
	},
	[w83l771] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
		.alert_alarms = 0x7c,
		.max_convrate = 8,
	},
	[sa56004] = {
		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
		.alert_alarms = 0x7b,
		.max_convrate = 9,
		.reg_local_ext = SA56004_REG_R_LOCAL_TEMPL,
	},
};

/*
 * Client data (each client gets its own)
 */

struct lm90_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */
	int kind;
	u32 flags;

	int update_interval;	/* in milliseconds */

	u8 config_orig;		/* Original configuration register value */
	u8 convrate_orig;	/* Original conversion rate register value */
	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
				/* Upper 8 bits for max6695/96 */
	u8 max_convrate;	/* Maximum conversion rate */
	u8 reg_local_ext;	/* local extension register offset */

	/* registers values */
	s8 temp8[8];	/* 0: local low limit
			 * 1: local high limit
			 * 2: local critical limit
			 * 3: remote critical limit
			 * 4: local emergency limit (max6659 and max6695/96)
			 * 5: remote emergency limit (max6659 and max6695/96)
			 * 6: remote 2 critical limit (max6695/96 only)
			 * 7: remote 2 emergency limit (max6695/96 only)
			 */
	s16 temp11[8];	/* 0: remote input
			 * 1: remote low limit
			 * 2: remote high limit
			 * 3: remote offset (except max6646, max6657/58/59,
			 *		     and max6695/96)
			 * 4: local input
			 * 5: remote 2 input (max6695/96 only)
			 * 6: remote 2 low limit (max6695/96 only)
			 * 7: remote 2 high limit (max6695/96 only)
			 */
	u8 temp_hyst;
	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
};

/*
 * Support functions
 */

/*
 * The ADM1032 supports PEC but not on write byte transactions, so we need
 * to explicitly ask for a transaction without PEC.
 */
static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
{
	return i2c_smbus_xfer(client->adapter, client->addr,
			      client->flags & ~I2C_CLIENT_PEC,
			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
}

/*
 * It is assumed that client->update_lock is held (unless we are in
 * detection or initialization steps). This matters when PEC is enabled,
 * because we don't want the address pointer to change between the write
 * byte and the read byte transactions.
 */
static int lm90_read_reg(struct i2c_client *client, u8 reg, u8 *value)
{
	int err;

	if (client->flags & I2C_CLIENT_PEC) {
		err = adm1032_write_byte(client, reg);
		if (err >= 0)
			err = i2c_smbus_read_byte(client);
	} else
		err = i2c_smbus_read_byte_data(client, reg);

	if (err < 0) {
		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
			 reg, err);
		return err;
	}
	*value = err;

	return 0;
}

static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
{
	int err;
	u8 oldh, newh, l;

	/*
	 * There is a trick here. We have to read two registers to have the
	 * sensor temperature, but we have to beware a conversion could occur
	 * between the readings. The datasheet says we should either use
	 * the one-shot conversion register, which we don't want to do
	 * (disables hardware monitoring) or monitor the busy bit, which is
	 * impossible (we can't read the values and monitor that bit at the
	 * exact same time). So the solution used here is to read the high
	 * byte once, then the low byte, then the high byte again. If the new
	 * high byte matches the old one, then we have a valid reading. Else
	 * we have to read the low byte again, and now we believe we have a
	 * correct reading.
	 */
	if ((err = lm90_read_reg(client, regh, &oldh))
	 || (err = lm90_read_reg(client, regl, &l))
	 || (err = lm90_read_reg(client, regh, &newh)))
		return err;
	if (oldh != newh) {
		err = lm90_read_reg(client, regl, &l);
		if (err)
			return err;
	}
	*value = (newh << 8) | l;

	return 0;
}

/*
 * client->update_lock must be held when calling this function (unless we are
 * in detection or initialization steps), and while a remote channel other
 * than channel 0 is selected. Also, calling code must make sure to re-select
 * external channel 0 before releasing the lock. This is necessary because
 * various registers have different meanings as a result of selecting a
 * non-default remote channel.
 */
static inline void lm90_select_remote_channel(struct i2c_client *client,
					      struct lm90_data *data,
					      int channel)
{
	u8 config;

	if (data->kind == max6696) {
		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
		config &= ~0x08;
		if (channel)
			config |= 0x08;
		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
					  config);
	}
}

/*
 * Set conversion rate.
 * client->update_lock must be held when calling this function (unless we are
 * in detection or initialization steps).
 */
static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
			      unsigned int interval)
{
	int i;
	unsigned int update_interval;

	/* Shift calculations to avoid rounding errors */
	interval <<= 6;

	/* find the nearest update rate */
	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
	     i < data->max_convrate; i++, update_interval >>= 1)
		if (interval >= update_interval * 3 / 4)
			break;

	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
}

static struct lm90_data *lm90_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	unsigned long next_update;

	mutex_lock(&data->update_lock);

	next_update = data->last_updated
	  + msecs_to_jiffies(data->update_interval) + 1;
	if (time_after(jiffies, next_update) || !data->valid) {
		u8 h, l;
		u8 alarms;

		dev_dbg(&client->dev, "Updating lm90 data.\n");
		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);

		if (data->reg_local_ext) {
			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
				    data->reg_local_ext,
				    &data->temp11[4]);
		} else {
			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
					  &h) == 0)
				data->temp11[4] = h << 8;
		}
		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
			    LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);

		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
			data->temp11[1] = h << 8;
			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
					  &l) == 0)
				data->temp11[1] |= l;
		}
		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
			data->temp11[2] = h << 8;
			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
					  &l) == 0)
				data->temp11[2] |= l;
		}

		if (data->flags & LM90_HAVE_OFFSET) {
			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
					  &h) == 0
			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
					  &l) == 0)
				data->temp11[3] = (h << 8) | l;
		}
		if (data->flags & LM90_HAVE_EMERGENCY) {
			lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
				      &data->temp8[4]);
			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
				      &data->temp8[5]);
		}
		lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
		data->alarms = alarms;	/* save as 16 bit value */

		if (data->kind == max6696) {
			lm90_select_remote_channel(client, data, 1);
			lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
				      &data->temp8[6]);
			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
				      &data->temp8[7]);
			lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
				    LM90_REG_R_REMOTE_TEMPL, &data->temp11[5]);
			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h))
				data->temp11[6] = h << 8;
			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h))
				data->temp11[7] = h << 8;
			lm90_select_remote_channel(client, data, 0);

			if (!lm90_read_reg(client, MAX6696_REG_R_STATUS2,
					   &alarms))
				data->alarms |= alarms << 8;
		}

		/*
		 * Re-enable ALERT# output if it was originally enabled and
		 * relevant alarms are all clear
		 */
		if ((data->config_orig & 0x80) == 0
		 && (data->alarms & data->alert_alarms) == 0) {
			u8 config;

			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
			if (config & 0x80) {
				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
				i2c_smbus_write_byte_data(client,
							  LM90_REG_W_CONFIG1,
							  config & ~0x80);
			}
		}

		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

/*
 * Conversions
 * For local temperatures and limits, critical limits and the hysteresis
 * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
 * For remote temperatures and limits, it uses signed 11-bit values with
 * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
 * Maxim chips use unsigned values.
 */

static inline int temp_from_s8(s8 val)
{
	return val * 1000;
}

static inline int temp_from_u8(u8 val)
{
	return val * 1000;
}

static inline int temp_from_s16(s16 val)
{
	return val / 32 * 125;
}

static inline int temp_from_u16(u16 val)
{
	return val / 32 * 125;
}

static s8 temp_to_s8(long val)
{
	if (val <= -128000)
		return -128;
	if (val >= 127000)
		return 127;
	if (val < 0)
		return (val - 500) / 1000;
	return (val + 500) / 1000;
}

static u8 temp_to_u8(long val)
{
	if (val <= 0)
		return 0;
	if (val >= 255000)
		return 255;
	return (val + 500) / 1000;
}

static s16 temp_to_s16(long val)
{
	if (val <= -128000)
		return 0x8000;
	if (val >= 127875)
		return 0x7FE0;
	if (val < 0)
		return (val - 62) / 125 * 32;
	return (val + 62) / 125 * 32;
}

static u8 hyst_to_reg(long val)
{
	if (val <= 0)
		return 0;
	if (val >= 30500)
		return 31;
	return (val + 500) / 1000;
}

/*
 * ADT7461 in compatibility mode is almost identical to LM90 except that
 * attempts to write values that are outside the range 0 < temp < 127 are
 * treated as the boundary value.
 *
 * ADT7461 in "extended mode" operation uses unsigned integers offset by
 * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
 */
static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
{
	if (data->flags & LM90_FLAG_ADT7461_EXT)
		return (val - 64) * 1000;
	else
		return temp_from_s8(val);
}

static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
{
	if (data->flags & LM90_FLAG_ADT7461_EXT)
		return (val - 0x4000) / 64 * 250;
	else
		return temp_from_s16(val);
}

static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
{
	if (data->flags & LM90_FLAG_ADT7461_EXT) {
		if (val <= -64000)
			return 0;
		if (val >= 191000)
			return 0xFF;
		return (val + 500 + 64000) / 1000;
	} else {
		if (val <= 0)
			return 0;
		if (val >= 127000)
			return 127;
		return (val + 500) / 1000;
	}
}

static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
{
	if (data->flags & LM90_FLAG_ADT7461_EXT) {
		if (val <= -64000)
			return 0;
		if (val >= 191750)
			return 0xFFC0;
		return (val + 64000 + 125) / 250 * 64;
	} else {
		if (val <= 0)
			return 0;
		if (val >= 127750)
			return 0x7FC0;
		return (val + 125) / 250 * 64;
	}
}

/*
 * Sysfs stuff
 */

static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
			  char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	int temp;

	if (data->kind == adt7461)
		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
	else if (data->kind == max6646)
		temp = temp_from_u8(data->temp8[attr->index]);
	else
		temp = temp_from_s8(data->temp8[attr->index]);

	/* +16 degrees offset for temp2 for the LM99 */
	if (data->kind == lm99 && attr->index == 3)
		temp += 16000;

	return sprintf(buf, "%d\n", temp);
}

static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
			 const char *buf, size_t count)
{
	static const u8 reg[8] = {
		LM90_REG_W_LOCAL_LOW,
		LM90_REG_W_LOCAL_HIGH,
		LM90_REG_W_LOCAL_CRIT,
		LM90_REG_W_REMOTE_CRIT,
		MAX6659_REG_W_LOCAL_EMERG,
		MAX6659_REG_W_REMOTE_EMERG,
		LM90_REG_W_REMOTE_CRIT,
		MAX6659_REG_W_REMOTE_EMERG,
	};

	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	int nr = attr->index;
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
		return err;

	/* +16 degrees offset for temp2 for the LM99 */
	if (data->kind == lm99 && attr->index == 3)
		val -= 16000;

	mutex_lock(&data->update_lock);
	if (data->kind == adt7461)
		data->temp8[nr] = temp_to_u8_adt7461(data, val);
	else if (data->kind == max6646)
		data->temp8[nr] = temp_to_u8(val);
	else
		data->temp8[nr] = temp_to_s8(val);

	lm90_select_remote_channel(client, data, nr >= 6);
	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
	lm90_select_remote_channel(client, data, 0);

	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
			   char *buf)
{
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	int temp;

	if (data->kind == adt7461)
		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
	else if (data->kind == max6646)
		temp = temp_from_u16(data->temp11[attr->index]);
	else
		temp = temp_from_s16(data->temp11[attr->index]);

	/* +16 degrees offset for temp2 for the LM99 */
	if (data->kind == lm99 &&  attr->index <= 2)
		temp += 16000;

	return sprintf(buf, "%d\n", temp);
}

static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
			  const char *buf, size_t count)
{
	struct {
		u8 high;
		u8 low;
		int channel;
	} reg[5] = {
		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 0 },
		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 0 },
		{ LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL, 0 },
		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 1 },
		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
	};

	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	int nr = attr->nr;
	int index = attr->index;
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
		return err;

	/* +16 degrees offset for temp2 for the LM99 */
	if (data->kind == lm99 && index <= 2)
		val -= 16000;

	mutex_lock(&data->update_lock);
	if (data->kind == adt7461)
		data->temp11[index] = temp_to_u16_adt7461(data, val);
	else if (data->kind == max6646)
		data->temp11[index] = temp_to_u8(val) << 8;
	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
		data->temp11[index] = temp_to_s16(val);
	else
		data->temp11[index] = temp_to_s8(val) << 8;

	lm90_select_remote_channel(client, data, reg[nr].channel);
	i2c_smbus_write_byte_data(client, reg[nr].high,
				  data->temp11[index] >> 8);
	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
		i2c_smbus_write_byte_data(client, reg[nr].low,
					  data->temp11[index] & 0xff);
	lm90_select_remote_channel(client, data, 0);

	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temphyst(struct device *dev,
			     struct device_attribute *devattr,
			     char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	int temp;

	if (data->kind == adt7461)
		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
	else if (data->kind == max6646)
		temp = temp_from_u8(data->temp8[attr->index]);
	else
		temp = temp_from_s8(data->temp8[attr->index]);

	/* +16 degrees offset for temp2 for the LM99 */
	if (data->kind == lm99 && attr->index == 3)
		temp += 16000;

	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
}

static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
			    const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	long val;
	int err;
	int temp;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
		return err;

	mutex_lock(&data->update_lock);
	if (data->kind == adt7461)
		temp = temp_from_u8_adt7461(data, data->temp8[2]);
	else if (data->kind == max6646)
		temp = temp_from_u8(data->temp8[2]);
	else
		temp = temp_from_s8(data->temp8[2]);

	data->temp_hyst = hyst_to_reg(temp - val);
	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
				  data->temp_hyst);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
			   char *buf)
{
	struct lm90_data *data = lm90_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
}

static ssize_t show_alarm(struct device *dev, struct device_attribute
			  *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm90_data *data = lm90_update_device(dev);
	int bitnr = attr->index;

	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
}

static ssize_t show_update_interval(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	struct lm90_data *data = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", data->update_interval);
}

static ssize_t set_update_interval(struct device *dev,
				   struct device_attribute *attr,
				   const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	unsigned long val;
	int err;

	err = kstrtoul(buf, 10, &val);
	if (err)
		return err;

	mutex_lock(&data->update_lock);
	lm90_set_convrate(client, data, SENSORS_LIMIT(val, 0, 100000));
	mutex_unlock(&data->update_lock);

	return count;
}

static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 4);
static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 0, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 0);
static SENSOR_DEVICE_ATTR_2(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 0, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 1);
static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 1, 2);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 2);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 3);
static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
	set_temphyst, 2);
static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
static SENSOR_DEVICE_ATTR_2(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 2, 3);

/* Individual alarm files */
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
/* Raw alarm file for compatibility */
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
		   set_update_interval);

static struct attribute *lm90_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,

	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&dev_attr_alarms.attr,
	&dev_attr_update_interval.attr,
	NULL
};

static const struct attribute_group lm90_group = {
	.attrs = lm90_attributes,
};

/*
 * Additional attributes for devices with emergency sensors
 */
static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 4);
static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 5);
static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
			  NULL, 4);
static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
			  NULL, 5);

static struct attribute *lm90_emergency_attributes[] = {
	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
	NULL
};

static const struct attribute_group lm90_emergency_group = {
	.attrs = lm90_emergency_attributes,
};

static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 15);
static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 13);

static struct attribute *lm90_emergency_alarm_attributes[] = {
	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group lm90_emergency_alarm_group = {
	.attrs = lm90_emergency_alarm_attributes,
};

/*
 * Additional attributes for devices with 3 temperature sensors
 */
static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL, 0, 5);
static SENSOR_DEVICE_ATTR_2(temp3_min, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 3, 6);
static SENSOR_DEVICE_ATTR_2(temp3_max, S_IWUSR | S_IRUGO, show_temp11,
	set_temp11, 4, 7);
static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 6);
static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_temphyst, NULL, 6);
static SENSOR_DEVICE_ATTR(temp3_emergency, S_IWUSR | S_IRUGO, show_temp8,
	set_temp8, 7);
static SENSOR_DEVICE_ATTR(temp3_emergency_hyst, S_IRUGO, show_temphyst,
			  NULL, 7);

static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 10);
static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 11);
static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 12);
static SENSOR_DEVICE_ATTR(temp3_emergency_alarm, S_IRUGO, show_alarm, NULL, 14);

static struct attribute *lm90_temp3_attributes[] = {
	&sensor_dev_attr_temp3_input.dev_attr.attr,
	&sensor_dev_attr_temp3_min.dev_attr.attr,
	&sensor_dev_attr_temp3_max.dev_attr.attr,
	&sensor_dev_attr_temp3_crit.dev_attr.attr,
	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
	&sensor_dev_attr_temp3_emergency.dev_attr.attr,
	&sensor_dev_attr_temp3_emergency_hyst.dev_attr.attr,

	&sensor_dev_attr_temp3_fault.dev_attr.attr,
	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_emergency_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group lm90_temp3_group = {
	.attrs = lm90_temp3_attributes,
};

/* pec used for ADM1032 only */
static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
			char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
}

static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
		       const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
		return err;

	switch (val) {
	case 0:
		client->flags &= ~I2C_CLIENT_PEC;
		break;
	case 1:
		client->flags |= I2C_CLIENT_PEC;
		break;
	default:
		return -EINVAL;
	}

	return count;
}

static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);

/*
 * Real code
 */

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm90_detect(struct i2c_client *client,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	int address = client->addr;
	const char *name = NULL;
	int man_id, chip_id, config1, config2, convrate;

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

	/* detection and identification */
	man_id = i2c_smbus_read_byte_data(client, LM90_REG_R_MAN_ID);
	chip_id = i2c_smbus_read_byte_data(client, LM90_REG_R_CHIP_ID);
	config1 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
	convrate = i2c_smbus_read_byte_data(client, LM90_REG_R_CONVRATE);
	if (man_id < 0 || chip_id < 0 || config1 < 0 || convrate < 0)
		return -ENODEV;

	if (man_id == 0x01 || man_id == 0x5C || man_id == 0x41) {
		config2 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG2);
		if (config2 < 0)
			return -ENODEV;
	} else
		config2 = 0;		/* Make compiler happy */

	if ((address == 0x4C || address == 0x4D)
	 && man_id == 0x01) { /* National Semiconductor */
		if ((config1 & 0x2A) == 0x00
		 && (config2 & 0xF8) == 0x00
		 && convrate <= 0x09) {
			if (address == 0x4C
			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
				name = "lm90";
			} else
			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
				name = "lm99";
				dev_info(&adapter->dev,
					 "Assuming LM99 chip at 0x%02x\n",
					 address);
				dev_info(&adapter->dev,
					 "If it is an LM89, instantiate it "
					 "with the new_device sysfs "
					 "interface\n");
			} else
			if (address == 0x4C
			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
				name = "lm86";
			}
		}
	} else
	if ((address == 0x4C || address == 0x4D)
	 && man_id == 0x41) { /* Analog Devices */
		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
		 && (config1 & 0x3F) == 0x00
		 && convrate <= 0x0A) {
			name = "adm1032";
			/*
			 * The ADM1032 supports PEC, but only if combined
			 * transactions are not used.
			 */
			if (i2c_check_functionality(adapter,
						    I2C_FUNC_SMBUS_BYTE))
				info->flags |= I2C_CLIENT_PEC;
		} else
		if (chip_id == 0x51 /* ADT7461 */
		 && (config1 & 0x1B) == 0x00
		 && convrate <= 0x0A) {
			name = "adt7461";
		} else
		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
		 && (config1 & 0x1B) == 0x00
		 && convrate <= 0x0A) {
			name = "adt7461a";
		}
	} else
	if (man_id == 0x4D) { /* Maxim */
		int emerg, emerg2, status2;

		/*
		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
		 * exists, both readings will reflect the same value. Otherwise,
		 * the readings will be different.
		 */
		emerg = i2c_smbus_read_byte_data(client,
						 MAX6659_REG_R_REMOTE_EMERG);
		man_id = i2c_smbus_read_byte_data(client,
						  LM90_REG_R_MAN_ID);
		emerg2 = i2c_smbus_read_byte_data(client,
						  MAX6659_REG_R_REMOTE_EMERG);
		status2 = i2c_smbus_read_byte_data(client,
						   MAX6696_REG_R_STATUS2);
		if (emerg < 0 || man_id < 0 || emerg2 < 0 || status2 < 0)
			return -ENODEV;

		/*
		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
		 * register. Reading from that address will return the last
		 * read value, which in our case is those of the man_id
		 * register. Likewise, the config1 register seems to lack a
		 * low nibble, so the value will be those of the previous
		 * read, so in our case those of the man_id register.
		 * MAX6659 has a third set of upper temperature limit registers.
		 * Those registers also return values on MAX6657 and MAX6658,
		 * thus the only way to detect MAX6659 is by its address.
		 * For this reason it will be mis-detected as MAX6657 if its
		 * address is 0x4C.
		 */
		if (chip_id == man_id
		 && (address == 0x4C || address == 0x4D || address == 0x4E)
		 && (config1 & 0x1F) == (man_id & 0x0F)
		 && convrate <= 0x09) {
			if (address == 0x4C)
				name = "max6657";
			else
				name = "max6659";
		} else
		/*
		 * Even though MAX6695 and MAX6696 do not have a chip ID
		 * register, reading it returns 0x01. Bit 4 of the config1
		 * register is unused and should return zero when read. Bit 0 of
		 * the status2 register is unused and should return zero when
		 * read.
		 *
		 * MAX6695 and MAX6696 have an additional set of temperature
		 * limit registers. We can detect those chips by checking if
		 * one of those registers exists.
		 */
		if (chip_id == 0x01
		 && (config1 & 0x10) == 0x00
		 && (status2 & 0x01) == 0x00
		 && emerg == emerg2
		 && convrate <= 0x07) {
			name = "max6696";
		} else
		/*
		 * The chip_id register of the MAX6680 and MAX6681 holds the
		 * revision of the chip. The lowest bit of the config1 register
		 * is unused and should return zero when read, so should the
		 * second to last bit of config1 (software reset).
		 */
		if (chip_id == 0x01
		 && (config1 & 0x03) == 0x00
		 && convrate <= 0x07) {
			name = "max6680";
		} else
		/*
		 * The chip_id register of the MAX6646/6647/6649 holds the
		 * revision of the chip. The lowest 6 bits of the config1
		 * register are unused and should return zero when read.
		 */
		if (chip_id == 0x59
		 && (config1 & 0x3f) == 0x00
		 && convrate <= 0x07) {
			name = "max6646";
		}
	} else
	if (address == 0x4C
	 && man_id == 0x5C) { /* Winbond/Nuvoton */
		if ((config1 & 0x2A) == 0x00
		 && (config2 & 0xF8) == 0x00) {
			if (chip_id == 0x01 /* W83L771W/G */
			 && convrate <= 0x09) {
				name = "w83l771";
			} else
			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
			 && convrate <= 0x08) {
				name = "w83l771";
			}
		}
	} else
	if (address >= 0x48 && address <= 0x4F
	 && man_id == 0xA1) { /*  NXP Semiconductor/Philips */
		if (chip_id == 0x00
		 && (config1 & 0x2A) == 0x00
		 && (config2 & 0xFE) == 0x00
		 && convrate <= 0x09) {
			name = "sa56004";
		}
	}

	if (!name) { /* identification failed */
		dev_dbg(&adapter->dev,
			"Unsupported chip at 0x%02x (man_id=0x%02X, "
			"chip_id=0x%02X)\n", address, man_id, chip_id);
		return -ENODEV;
	}

	strlcpy(info->type, name, I2C_NAME_SIZE);

	return 0;
}

static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
{
	struct device *dev = &client->dev;

	if (data->flags & LM90_HAVE_TEMP3)
		sysfs_remove_group(&dev->kobj, &lm90_temp3_group);
	if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
		sysfs_remove_group(&dev->kobj, &lm90_emergency_alarm_group);
	if (data->flags & LM90_HAVE_EMERGENCY)
		sysfs_remove_group(&dev->kobj, &lm90_emergency_group);
	if (data->flags & LM90_HAVE_OFFSET)
		device_remove_file(dev, &sensor_dev_attr_temp2_offset.dev_attr);
	device_remove_file(dev, &dev_attr_pec);
	sysfs_remove_group(&dev->kobj, &lm90_group);
}

static void lm90_init_client(struct i2c_client *client)
{
	u8 config, convrate;
	struct lm90_data *data = i2c_get_clientdata(client);

	if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) {
		dev_warn(&client->dev, "Failed to read convrate register!\n");
		convrate = LM90_DEF_CONVRATE_RVAL;
	}
	data->convrate_orig = convrate;

	/*
	 * Start the conversions.
	 */
	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
		dev_warn(&client->dev, "Initialization failed!\n");
		return;
	}
	data->config_orig = config;

	/* Check Temperature Range Select */
	if (data->kind == adt7461) {
		if (config & 0x04)
			data->flags |= LM90_FLAG_ADT7461_EXT;
	}

	/*
	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
	 * 0.125 degree resolution) and range (0x08, extend range
	 * to -64 degree) mode for the remote temperature sensor.
	 */
	if (data->kind == max6680)
		config |= 0x18;

	/*
	 * Select external channel 0 for max6695/96
	 */
	if (data->kind == max6696)
		config &= ~0x08;

	config &= 0xBF;	/* run */
	if (config != data->config_orig) /* Only write if changed */
		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
}

static int lm90_probe(struct i2c_client *client,
		      const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
	struct lm90_data *data;
	int err;

	data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}
	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* Set the device type */
	data->kind = id->driver_data;
	if (data->kind == adm1032) {
		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
			client->flags &= ~I2C_CLIENT_PEC;
	}

	/*
	 * Different devices have different alarm bits triggering the
	 * ALERT# output
	 */
	data->alert_alarms = lm90_params[data->kind].alert_alarms;

	/* Set chip capabilities */
	data->flags = lm90_params[data->kind].flags;
	data->reg_local_ext = lm90_params[data->kind].reg_local_ext;

	/* Set maximum conversion rate */
	data->max_convrate = lm90_params[data->kind].max_convrate;

	/* Initialize the LM90 chip */
	lm90_init_client(client);

	/* Register sysfs hooks */
	err = sysfs_create_group(&dev->kobj, &lm90_group);
	if (err)
		goto exit_free;
	if (client->flags & I2C_CLIENT_PEC) {
		err = device_create_file(dev, &dev_attr_pec);
		if (err)
			goto exit_remove_files;
	}
	if (data->flags & LM90_HAVE_OFFSET) {
		err = device_create_file(dev,
					&sensor_dev_attr_temp2_offset.dev_attr);
		if (err)
			goto exit_remove_files;
	}
	if (data->flags & LM90_HAVE_EMERGENCY) {
		err = sysfs_create_group(&dev->kobj, &lm90_emergency_group);
		if (err)
			goto exit_remove_files;
	}
	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
		err = sysfs_create_group(&dev->kobj,
					 &lm90_emergency_alarm_group);
		if (err)
			goto exit_remove_files;
	}
	if (data->flags & LM90_HAVE_TEMP3) {
		err = sysfs_create_group(&dev->kobj, &lm90_temp3_group);
		if (err)
			goto exit_remove_files;
	}

	data->hwmon_dev = hwmon_device_register(dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto exit_remove_files;
	}

	return 0;

exit_remove_files:
	lm90_remove_files(client, data);
exit_free:
	kfree(data);
exit:
	return err;
}

static int lm90_remove(struct i2c_client *client)
{
	struct lm90_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	lm90_remove_files(client, data);

	/* Restore initial configuration */
	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
				  data->convrate_orig);
	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
				  data->config_orig);

	kfree(data);
	return 0;
}

static void lm90_alert(struct i2c_client *client, unsigned int flag)
{
	struct lm90_data *data = i2c_get_clientdata(client);
	u8 config, alarms, alarms2 = 0;

	lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);

	if (data->kind == max6696)
		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms2);

	if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) {
		dev_info(&client->dev, "Everything OK\n");
	} else {
		if (alarms & 0x61)
			dev_warn(&client->dev,
				 "temp%d out of range, please check!\n", 1);
		if (alarms & 0x1a)
			dev_warn(&client->dev,
				 "temp%d out of range, please check!\n", 2);
		if (alarms & 0x04)
			dev_warn(&client->dev,
				 "temp%d diode open, please check!\n", 2);

		if (alarms2 & 0x18)
			dev_warn(&client->dev,
				 "temp%d out of range, please check!\n", 3);

		/*
		 * Disable ALERT# output, because these chips don't implement
		 * SMBus alert correctly; they should only hold the alert line
		 * low briefly.
		 */
		if ((data->flags & LM90_HAVE_BROKEN_ALERT)
		 && (alarms & data->alert_alarms)) {
			dev_dbg(&client->dev, "Disabling ALERT#\n");
			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
			i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
						  config | 0x80);
		}
	}
}

static struct i2c_driver lm90_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm90",
	},
	.probe		= lm90_probe,
	.remove		= lm90_remove,
	.alert		= lm90_alert,
	.id_table	= lm90_id,
	.detect		= lm90_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(lm90_driver);

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("LM90/ADM1032 driver");
MODULE_LICENSE("GPL");