summaryrefslogtreecommitdiff
path: root/drivers/hwmon/lm75.c
blob: bcc3adcb3af1a5574b0f0ac1d2095b5e52cf117d (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lm75.c - Part of lm_sensors, Linux kernel modules for hardware
 *	 monitoring
 * Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>
#include <linux/regulator/consumer.h>
#include "lm75.h"

/*
 * This driver handles the LM75 and compatible digital temperature sensors.
 */

enum lm75_type {		/* keep sorted in alphabetical order */
	adt75,
	at30ts74,
	ds1775,
	ds75,
	ds7505,
	g751,
	lm75,
	lm75a,
	lm75b,
	max6625,
	max6626,
	max31725,
	mcp980x,
	pct2075,
	stds75,
	stlm75,
	tcn75,
	tmp100,
	tmp101,
	tmp105,
	tmp112,
	tmp175,
	tmp275,
	tmp75,
	tmp75b,
	tmp75c,
	tmp1075,
};

/**
 * struct lm75_params - lm75 configuration parameters.
 * @set_mask:		Bits to set in configuration register when configuring
 *			the chip.
 * @clr_mask:		Bits to clear in configuration register when configuring
 *			the chip.
 * @default_resolution:	Default number of bits to represent the temperature
 *			value.
 * @resolution_limits:	Limit register resolution. Optional. Should be set if
 *			the resolution of limit registers does not match the
 *			resolution of the temperature register.
 * @resolutions:	List of resolutions associated with sample times.
 *			Optional. Should be set if num_sample_times is larger
 *			than 1, and if the resolution changes with sample times.
 *			If set, number of entries must match num_sample_times.
 * @default_sample_time:Sample time to be set by default.
 * @num_sample_times:	Number of possible sample times to be set. Optional.
 *			Should be set if the number of sample times is larger
 *			than one.
 * @sample_times:	All the possible sample times to be set. Mandatory if
 *			num_sample_times is larger than 1. If set, number of
 *			entries must match num_sample_times.
 */

struct lm75_params {
	u8			set_mask;
	u8			clr_mask;
	u8			default_resolution;
	u8			resolution_limits;
	const u8		*resolutions;
	unsigned int		default_sample_time;
	u8			num_sample_times;
	const unsigned int	*sample_times;
};

/* Addresses scanned */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
					0x4d, 0x4e, 0x4f, I2C_CLIENT_END };

/* The LM75 registers */
#define LM75_REG_TEMP		0x00
#define LM75_REG_CONF		0x01
#define LM75_REG_HYST		0x02
#define LM75_REG_MAX		0x03
#define PCT2075_REG_IDLE	0x04

/* Each client has this additional data */
struct lm75_data {
	struct i2c_client		*client;
	struct regmap			*regmap;
	struct regulator		*vs;
	u8				orig_conf;
	u8				current_conf;
	u8				resolution;	/* In bits, 9 to 16 */
	unsigned int			sample_time;	/* In ms */
	enum lm75_type			kind;
	const struct lm75_params	*params;
};

/*-----------------------------------------------------------------------*/

static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 };

#define LM75_SAMPLE_CLEAR_MASK	(3 << 5)

/* The structure below stores the configuration values of the supported devices.
 * In case of being supported multiple configurations, the default one must
 * always be the first element of the array
 */
static const struct lm75_params device_params[] = {
	[adt75] = {
		.clr_mask = 1 << 5,	/* not one-shot mode */
		.default_resolution = 12,
		.default_sample_time = MSEC_PER_SEC / 10,
	},
	[at30ts74] = {
		.set_mask = 3 << 5,	/* 12-bit mode*/
		.default_resolution = 12,
		.default_sample_time = 200,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 25, 50, 100, 200 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[ds1775] = {
		.clr_mask = 3 << 5,
		.set_mask = 2 << 5,	/* 11-bit mode */
		.default_resolution = 11,
		.default_sample_time = 500,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 125, 250, 500, 1000 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[ds75] = {
		.clr_mask = 3 << 5,
		.set_mask = 2 << 5,	/* 11-bit mode */
		.default_resolution = 11,
		.default_sample_time = 600,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 150, 300, 600, 1200 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[stds75] = {
		.clr_mask = 3 << 5,
		.set_mask = 2 << 5,	/* 11-bit mode */
		.default_resolution = 11,
		.default_sample_time = 600,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 150, 300, 600, 1200 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[stlm75] = {
		.default_resolution = 9,
		.default_sample_time = MSEC_PER_SEC / 6,
	},
	[ds7505] = {
		.set_mask = 3 << 5,	/* 12-bit mode*/
		.default_resolution = 12,
		.default_sample_time = 200,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 25, 50, 100, 200 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[g751] = {
		.default_resolution = 9,
		.default_sample_time = MSEC_PER_SEC / 10,
	},
	[lm75] = {
		.default_resolution = 9,
		.default_sample_time = MSEC_PER_SEC / 10,
	},
	[lm75a] = {
		.default_resolution = 9,
		.default_sample_time = MSEC_PER_SEC / 10,
	},
	[lm75b] = {
		.default_resolution = 11,
		.default_sample_time = MSEC_PER_SEC / 10,
	},
	[max6625] = {
		.default_resolution = 9,
		.default_sample_time = MSEC_PER_SEC / 7,
	},
	[max6626] = {
		.default_resolution = 12,
		.default_sample_time = MSEC_PER_SEC / 7,
		.resolution_limits = 9,
	},
	[max31725] = {
		.default_resolution = 16,
		.default_sample_time = MSEC_PER_SEC / 20,
	},
	[tcn75] = {
		.default_resolution = 9,
		.default_sample_time = MSEC_PER_SEC / 18,
	},
	[pct2075] = {
		.default_resolution = 11,
		.default_sample_time = MSEC_PER_SEC / 10,
		.num_sample_times = 31,
		.sample_times = (unsigned int []){ 100, 200, 300, 400, 500, 600,
		700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700,
		1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700,
		2800, 2900, 3000, 3100 },
	},
	[mcp980x] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode */
		.default_resolution = 12,
		.resolution_limits = 9,
		.default_sample_time = 240,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 30, 60, 120, 240 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp100] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode */
		.default_resolution = 12,
		.default_sample_time = 320,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 40, 80, 160, 320 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp101] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode */
		.default_resolution = 12,
		.default_sample_time = 320,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 40, 80, 160, 320 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp105] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode*/
		.default_resolution = 12,
		.default_sample_time = 220,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 28, 55, 110, 220 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp112] = {
		.set_mask = 3 << 5,	/* 8 samples / second */
		.clr_mask = 1 << 7,	/* no one-shot mode*/
		.default_resolution = 12,
		.default_sample_time = 125,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 125, 250, 1000, 4000 },
	},
	[tmp175] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode*/
		.default_resolution = 12,
		.default_sample_time = 220,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 28, 55, 110, 220 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp275] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode*/
		.default_resolution = 12,
		.default_sample_time = 220,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 28, 55, 110, 220 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp75] = {
		.set_mask = 3 << 5,	/* 12-bit mode */
		.clr_mask = 1 << 7,	/* not one-shot mode*/
		.default_resolution = 12,
		.default_sample_time = 220,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 28, 55, 110, 220 },
		.resolutions = (u8 []) {9, 10, 11, 12 },
	},
	[tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */
		.clr_mask = 1 << 7 | 3 << 5,
		.default_resolution = 12,
		.default_sample_time = MSEC_PER_SEC / 37,
		.sample_times = (unsigned int []){ MSEC_PER_SEC / 37,
			MSEC_PER_SEC / 18,
			MSEC_PER_SEC / 9, MSEC_PER_SEC / 4 },
		.num_sample_times = 4,
	},
	[tmp75c] = {
		.clr_mask = 1 << 5,	/*not one-shot mode*/
		.default_resolution = 12,
		.default_sample_time = MSEC_PER_SEC / 12,
	},
	[tmp1075] = { /* not one-shot mode, 27.5 ms sample rate */
		.clr_mask = 1 << 5 | 1 << 6 | 1 << 7,
		.default_resolution = 12,
		.default_sample_time = 28,
		.num_sample_times = 4,
		.sample_times = (unsigned int []){ 28, 55, 110, 220 },
	}
};

static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
{
	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
}

static int lm75_write_config(struct lm75_data *data, u8 set_mask,
			     u8 clr_mask)
{
	u8 value;

	clr_mask |= LM75_SHUTDOWN;
	value = data->current_conf & ~clr_mask;
	value |= set_mask;

	if (data->current_conf != value) {
		s32 err;

		err = i2c_smbus_write_byte_data(data->client, LM75_REG_CONF,
						value);
		if (err)
			return err;
		data->current_conf = value;
	}
	return 0;
}

static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
		     u32 attr, int channel, long *val)
{
	struct lm75_data *data = dev_get_drvdata(dev);
	unsigned int regval;
	int err, reg;

	switch (type) {
	case hwmon_chip:
		switch (attr) {
		case hwmon_chip_update_interval:
			*val = data->sample_time;
			break;
		default:
			return -EINVAL;
		}
		break;
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_input:
			reg = LM75_REG_TEMP;
			break;
		case hwmon_temp_max:
			reg = LM75_REG_MAX;
			break;
		case hwmon_temp_max_hyst:
			reg = LM75_REG_HYST;
			break;
		default:
			return -EINVAL;
		}
		err = regmap_read(data->regmap, reg, &regval);
		if (err < 0)
			return err;

		*val = lm75_reg_to_mc(regval, data->resolution);
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int lm75_write_temp(struct device *dev, u32 attr, long temp)
{
	struct lm75_data *data = dev_get_drvdata(dev);
	u8 resolution;
	int reg;

	switch (attr) {
	case hwmon_temp_max:
		reg = LM75_REG_MAX;
		break;
	case hwmon_temp_max_hyst:
		reg = LM75_REG_HYST;
		break;
	default:
		return -EINVAL;
	}

	/*
	 * Resolution of limit registers is assumed to be the same as the
	 * temperature input register resolution unless given explicitly.
	 */
	if (data->params->resolution_limits)
		resolution = data->params->resolution_limits;
	else
		resolution = data->resolution;

	temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
	temp = DIV_ROUND_CLOSEST(temp  << (resolution - 8),
				 1000) << (16 - resolution);

	return regmap_write(data->regmap, reg, (u16)temp);
}

static int lm75_update_interval(struct device *dev, long val)
{
	struct lm75_data *data = dev_get_drvdata(dev);
	unsigned int reg;
	u8 index;
	s32 err;

	index = find_closest(val, data->params->sample_times,
			     (int)data->params->num_sample_times);

	switch (data->kind) {
	default:
		err = lm75_write_config(data, lm75_sample_set_masks[index],
					LM75_SAMPLE_CLEAR_MASK);
		if (err)
			return err;

		data->sample_time = data->params->sample_times[index];
		if (data->params->resolutions)
			data->resolution = data->params->resolutions[index];
		break;
	case tmp112:
		err = regmap_read(data->regmap, LM75_REG_CONF, &reg);
		if (err < 0)
			return err;
		reg &= ~0x00c0;
		reg |= (3 - index) << 6;
		err = regmap_write(data->regmap, LM75_REG_CONF, reg);
		if (err < 0)
			return err;
		data->sample_time = data->params->sample_times[index];
		break;
	case pct2075:
		err = i2c_smbus_write_byte_data(data->client, PCT2075_REG_IDLE,
						index + 1);
		if (err)
			return err;
		data->sample_time = data->params->sample_times[index];
		break;
	}
	return 0;
}

static int lm75_write_chip(struct device *dev, u32 attr, long val)
{
	switch (attr) {
	case hwmon_chip_update_interval:
		return lm75_update_interval(dev, val);
	default:
		return -EINVAL;
	}
	return 0;
}

static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
		      u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_chip:
		return lm75_write_chip(dev, attr, val);
	case hwmon_temp:
		return lm75_write_temp(dev, attr, val);
	default:
		return -EINVAL;
	}
	return 0;
}

static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
			       u32 attr, int channel)
{
	const struct lm75_data *config_data = data;

	switch (type) {
	case hwmon_chip:
		switch (attr) {
		case hwmon_chip_update_interval:
			if (config_data->params->num_sample_times > 1)
				return 0644;
			return 0444;
		}
		break;
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_input:
			return 0444;
		case hwmon_temp_max:
		case hwmon_temp_max_hyst:
			return 0644;
		}
		break;
	default:
		break;
	}
	return 0;
}

static const struct hwmon_channel_info *lm75_info[] = {
	HWMON_CHANNEL_INFO(chip,
			   HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
	NULL
};

static const struct hwmon_ops lm75_hwmon_ops = {
	.is_visible = lm75_is_visible,
	.read = lm75_read,
	.write = lm75_write,
};

static const struct hwmon_chip_info lm75_chip_info = {
	.ops = &lm75_hwmon_ops,
	.info = lm75_info,
};

static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
{
	return reg != LM75_REG_TEMP;
}

static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
{
	return reg == LM75_REG_TEMP || reg == LM75_REG_CONF;
}

static const struct regmap_config lm75_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = PCT2075_REG_IDLE,
	.writeable_reg = lm75_is_writeable_reg,
	.volatile_reg = lm75_is_volatile_reg,
	.val_format_endian = REGMAP_ENDIAN_BIG,
	.cache_type = REGCACHE_RBTREE,
	.use_single_read = true,
	.use_single_write = true,
};

static void lm75_disable_regulator(void *data)
{
	struct lm75_data *lm75 = data;

	regulator_disable(lm75->vs);
}

static void lm75_remove(void *data)
{
	struct lm75_data *lm75 = data;
	struct i2c_client *client = lm75->client;

	i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
}

static const struct i2c_device_id lm75_ids[];

static int lm75_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct lm75_data *data;
	int status, err;
	enum lm75_type kind;

	if (client->dev.of_node)
		kind = (enum lm75_type)of_device_get_match_data(&client->dev);
	else
		kind = i2c_match_id(lm75_ids, client)->driver_data;

	if (!i2c_check_functionality(client->adapter,
			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
		return -EIO;

	data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->client = client;
	data->kind = kind;

	data->vs = devm_regulator_get(dev, "vs");
	if (IS_ERR(data->vs))
		return PTR_ERR(data->vs);

	data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
	if (IS_ERR(data->regmap))
		return PTR_ERR(data->regmap);

	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
	 * Then tweak to be more precise when appropriate.
	 */

	data->params = &device_params[data->kind];

	/* Save default sample time and resolution*/
	data->sample_time = data->params->default_sample_time;
	data->resolution = data->params->default_resolution;

	/* Enable the power */
	err = regulator_enable(data->vs);
	if (err) {
		dev_err(dev, "failed to enable regulator: %d\n", err);
		return err;
	}

	err = devm_add_action_or_reset(dev, lm75_disable_regulator, data);
	if (err)
		return err;

	/* Cache original configuration */
	status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
	if (status < 0) {
		dev_dbg(dev, "Can't read config? %d\n", status);
		return status;
	}
	data->orig_conf = status;
	data->current_conf = status;

	err = lm75_write_config(data, data->params->set_mask,
				data->params->clr_mask);
	if (err)
		return err;

	err = devm_add_action_or_reset(dev, lm75_remove, data);
	if (err)
		return err;

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 data, &lm75_chip_info,
							 NULL);
	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

	dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);

	return 0;
}

static const struct i2c_device_id lm75_ids[] = {
	{ "adt75", adt75, },
	{ "at30ts74", at30ts74, },
	{ "ds1775", ds1775, },
	{ "ds75", ds75, },
	{ "ds7505", ds7505, },
	{ "g751", g751, },
	{ "lm75", lm75, },
	{ "lm75a", lm75a, },
	{ "lm75b", lm75b, },
	{ "max6625", max6625, },
	{ "max6626", max6626, },
	{ "max31725", max31725, },
	{ "max31726", max31725, },
	{ "mcp980x", mcp980x, },
	{ "pct2075", pct2075, },
	{ "stds75", stds75, },
	{ "stlm75", stlm75, },
	{ "tcn75", tcn75, },
	{ "tmp100", tmp100, },
	{ "tmp101", tmp101, },
	{ "tmp105", tmp105, },
	{ "tmp112", tmp112, },
	{ "tmp175", tmp175, },
	{ "tmp275", tmp275, },
	{ "tmp75", tmp75, },
	{ "tmp75b", tmp75b, },
	{ "tmp75c", tmp75c, },
	{ "tmp1075", tmp1075, },
	{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, lm75_ids);

static const struct of_device_id __maybe_unused lm75_of_match[] = {
	{
		.compatible = "adi,adt75",
		.data = (void *)adt75
	},
	{
		.compatible = "atmel,at30ts74",
		.data = (void *)at30ts74
	},
	{
		.compatible = "dallas,ds1775",
		.data = (void *)ds1775
	},
	{
		.compatible = "dallas,ds75",
		.data = (void *)ds75
	},
	{
		.compatible = "dallas,ds7505",
		.data = (void *)ds7505
	},
	{
		.compatible = "gmt,g751",
		.data = (void *)g751
	},
	{
		.compatible = "national,lm75",
		.data = (void *)lm75
	},
	{
		.compatible = "national,lm75a",
		.data = (void *)lm75a
	},
	{
		.compatible = "national,lm75b",
		.data = (void *)lm75b
	},
	{
		.compatible = "maxim,max6625",
		.data = (void *)max6625
	},
	{
		.compatible = "maxim,max6626",
		.data = (void *)max6626
	},
	{
		.compatible = "maxim,max31725",
		.data = (void *)max31725
	},
	{
		.compatible = "maxim,max31726",
		.data = (void *)max31725
	},
	{
		.compatible = "maxim,mcp980x",
		.data = (void *)mcp980x
	},
	{
		.compatible = "nxp,pct2075",
		.data = (void *)pct2075
	},
	{
		.compatible = "st,stds75",
		.data = (void *)stds75
	},
	{
		.compatible = "st,stlm75",
		.data = (void *)stlm75
	},
	{
		.compatible = "microchip,tcn75",
		.data = (void *)tcn75
	},
	{
		.compatible = "ti,tmp100",
		.data = (void *)tmp100
	},
	{
		.compatible = "ti,tmp101",
		.data = (void *)tmp101
	},
	{
		.compatible = "ti,tmp105",
		.data = (void *)tmp105
	},
	{
		.compatible = "ti,tmp112",
		.data = (void *)tmp112
	},
	{
		.compatible = "ti,tmp175",
		.data = (void *)tmp175
	},
	{
		.compatible = "ti,tmp275",
		.data = (void *)tmp275
	},
	{
		.compatible = "ti,tmp75",
		.data = (void *)tmp75
	},
	{
		.compatible = "ti,tmp75b",
		.data = (void *)tmp75b
	},
	{
		.compatible = "ti,tmp75c",
		.data = (void *)tmp75c
	},
	{
		.compatible = "ti,tmp1075",
		.data = (void *)tmp1075
	},
	{ },
};
MODULE_DEVICE_TABLE(of, lm75_of_match);

#define LM75A_ID 0xA1

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm75_detect(struct i2c_client *new_client,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;
	int i;
	int conf, hyst, os;
	bool is_lm75a = 0;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	/*
	 * Now, we do the remaining detection. There is no identification-
	 * dedicated register so we have to rely on several tricks:
	 * unused bits, registers cycling over 8-address boundaries,
	 * addresses 0x04-0x07 returning the last read value.
	 * The cycling+unused addresses combination is not tested,
	 * since it would significantly slow the detection down and would
	 * hardly add any value.
	 *
	 * The National Semiconductor LM75A is different than earlier
	 * LM75s.  It has an ID byte of 0xaX (where X is the chip
	 * revision, with 1 being the only revision in existence) in
	 * register 7, and unused registers return 0xff rather than the
	 * last read value.
	 *
	 * Note that this function only detects the original National
	 * Semiconductor LM75 and the LM75A. Clones from other vendors
	 * aren't detected, on purpose, because they are typically never
	 * found on PC hardware. They are found on embedded designs where
	 * they can be instantiated explicitly so detection is not needed.
	 * The absence of identification registers on all these clones
	 * would make their exhaustive detection very difficult and weak,
	 * and odds are that the driver would bind to unsupported devices.
	 */

	/* Unused bits */
	conf = i2c_smbus_read_byte_data(new_client, 1);
	if (conf & 0xe0)
		return -ENODEV;

	/* First check for LM75A */
	if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
		/*
		 * LM75A returns 0xff on unused registers so
		 * just to be sure we check for that too.
		 */
		if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
		 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
		 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
			return -ENODEV;
		is_lm75a = 1;
		hyst = i2c_smbus_read_byte_data(new_client, 2);
		os = i2c_smbus_read_byte_data(new_client, 3);
	} else { /* Traditional style LM75 detection */
		/* Unused addresses */
		hyst = i2c_smbus_read_byte_data(new_client, 2);
		if (i2c_smbus_read_byte_data(new_client, 4) != hyst
		 || i2c_smbus_read_byte_data(new_client, 5) != hyst
		 || i2c_smbus_read_byte_data(new_client, 6) != hyst
		 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
			return -ENODEV;
		os = i2c_smbus_read_byte_data(new_client, 3);
		if (i2c_smbus_read_byte_data(new_client, 4) != os
		 || i2c_smbus_read_byte_data(new_client, 5) != os
		 || i2c_smbus_read_byte_data(new_client, 6) != os
		 || i2c_smbus_read_byte_data(new_client, 7) != os)
			return -ENODEV;
	}
	/*
	 * It is very unlikely that this is a LM75 if both
	 * hysteresis and temperature limit registers are 0.
	 */
	if (hyst == 0 && os == 0)
		return -ENODEV;

	/* Addresses cycling */
	for (i = 8; i <= 248; i += 40) {
		if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
		 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
		 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
			return -ENODEV;
		if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
				!= LM75A_ID)
			return -ENODEV;
	}

	strscpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);

	return 0;
}

#ifdef CONFIG_PM
static int lm75_suspend(struct device *dev)
{
	int status;
	struct i2c_client *client = to_i2c_client(dev);

	status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
	if (status < 0) {
		dev_dbg(&client->dev, "Can't read config? %d\n", status);
		return status;
	}
	status = status | LM75_SHUTDOWN;
	i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
	return 0;
}

static int lm75_resume(struct device *dev)
{
	int status;
	struct i2c_client *client = to_i2c_client(dev);

	status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
	if (status < 0) {
		dev_dbg(&client->dev, "Can't read config? %d\n", status);
		return status;
	}
	status = status & ~LM75_SHUTDOWN;
	i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
	return 0;
}

static const struct dev_pm_ops lm75_dev_pm_ops = {
	.suspend	= lm75_suspend,
	.resume		= lm75_resume,
};
#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
#else
#define LM75_DEV_PM_OPS NULL
#endif /* CONFIG_PM */

static struct i2c_driver lm75_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm75",
		.of_match_table = of_match_ptr(lm75_of_match),
		.pm	= LM75_DEV_PM_OPS,
	},
	.probe_new	= lm75_probe,
	.id_table	= lm75_ids,
	.detect		= lm75_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(lm75_driver);

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
MODULE_DESCRIPTION("LM75 driver");
MODULE_LICENSE("GPL");