summaryrefslogtreecommitdiff
path: root/drivers/hwmon/pmbus/ltc2978.c
blob: 58b789c28b483f062b17822a32487be6bdba14ee (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
/*
 * Hardware monitoring driver for LTC2978 and compatible chips.
 *
 * Copyright (c) 2011 Ericsson AB.
 * Copyright (c) 2013, 2014, 2015 Guenter Roeck
 * Copyright (c) 2015 Linear Technology
 *
 * 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.
 */

#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/regulator/driver.h>
#include "pmbus.h"

enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc2980, ltc3880, ltc3882,
	ltc3883, ltc3886, ltc3887, ltm2987, ltm4675, ltm4676 };

/* Common for all chips */
#define LTC2978_MFR_VOUT_PEAK		0xdd
#define LTC2978_MFR_VIN_PEAK		0xde
#define LTC2978_MFR_TEMPERATURE_PEAK	0xdf
#define LTC2978_MFR_SPECIAL_ID		0xe7	/* Undocumented on LTC3882 */
#define LTC2978_MFR_COMMON		0xef

/* LTC2974, LTC2975, LCT2977, LTC2980, LTC2978, and LTM2987 */
#define LTC2978_MFR_VOUT_MIN		0xfb
#define LTC2978_MFR_VIN_MIN		0xfc
#define LTC2978_MFR_TEMPERATURE_MIN	0xfd

/* LTC2974, LTC2975 */
#define LTC2974_MFR_IOUT_PEAK		0xd7
#define LTC2974_MFR_IOUT_MIN		0xd8

/* LTC3880, LTC3882, LTC3883, LTC3887, LTM4675, and LTM4676 */
#define LTC3880_MFR_IOUT_PEAK		0xd7
#define LTC3880_MFR_CLEAR_PEAKS		0xe3
#define LTC3880_MFR_TEMPERATURE2_PEAK	0xf4

/* LTC3883 and LTC3886 only */
#define LTC3883_MFR_IIN_PEAK		0xe1

/* LTC2975 only */
#define LTC2975_MFR_IIN_PEAK		0xc4
#define LTC2975_MFR_IIN_MIN		0xc5
#define LTC2975_MFR_PIN_PEAK		0xc6
#define LTC2975_MFR_PIN_MIN		0xc7

#define LTC2978_ID_MASK			0xfff0

#define LTC2974_ID			0x0210
#define LTC2975_ID			0x0220
#define LTC2977_ID			0x0130
#define LTC2978_ID_REV1			0x0110	/* Early revision */
#define LTC2978_ID_REV2			0x0120
#define LTC2980_ID_A			0x8030	/* A/B for two die IDs */
#define LTC2980_ID_B			0x8040
#define LTC3880_ID			0x4020
#define LTC3882_ID			0x4200
#define LTC3882_ID_D1			0x4240	/* Dash 1 */
#define LTC3883_ID			0x4300
#define LTC3886_ID			0x4600
#define LTC3887_ID			0x4700
#define LTM2987_ID_A			0x8010	/* A/B for two die IDs */
#define LTM2987_ID_B			0x8020
#define LTM4675_ID			0x47a0
#define LTM4676_ID_REV1			0x4400
#define LTM4676_ID_REV2			0x4480
#define LTM4676A_ID			0x47e0

#define LTC2974_NUM_PAGES		4
#define LTC2978_NUM_PAGES		8
#define LTC3880_NUM_PAGES		2
#define LTC3883_NUM_PAGES		1

#define LTC_POLL_TIMEOUT		100	/* in milli-seconds */

#define LTC_NOT_BUSY			BIT(5)
#define LTC_NOT_PENDING			BIT(4)

/*
 * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
 * happens pretty much each time chip data is updated. Raw peak data therefore
 * does not provide much value. To be able to provide useful peak data, keep an
 * internal cache of measured peak data, which is only cleared if an explicit
 * "clear peak" command is executed for the sensor in question.
 */

struct ltc2978_data {
	enum chips id;
	u16 vin_min, vin_max;
	u16 temp_min[LTC2974_NUM_PAGES], temp_max[LTC2974_NUM_PAGES];
	u16 vout_min[LTC2978_NUM_PAGES], vout_max[LTC2978_NUM_PAGES];
	u16 iout_min[LTC2974_NUM_PAGES], iout_max[LTC2974_NUM_PAGES];
	u16 iin_min, iin_max;
	u16 pin_min, pin_max;
	u16 temp2_max;
	struct pmbus_driver_info info;
	u32 features;
};
#define to_ltc2978_data(x)  container_of(x, struct ltc2978_data, info)

#define FEAT_CLEAR_PEAKS	BIT(0)
#define FEAT_NEEDS_POLLING	BIT(1)

#define has_clear_peaks(d)	((d)->features & FEAT_CLEAR_PEAKS)
#define needs_polling(d)	((d)->features & FEAT_NEEDS_POLLING)

static int ltc_wait_ready(struct i2c_client *client)
{
	unsigned long timeout = jiffies + msecs_to_jiffies(LTC_POLL_TIMEOUT);
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int status;
	u8 mask;

	if (!needs_polling(data))
		return 0;

	/*
	 * LTC3883 does not support LTC_NOT_PENDING, even though
	 * the datasheet claims that it does.
	 */
	mask = LTC_NOT_BUSY;
	if (data->id != ltc3883)
		mask |= LTC_NOT_PENDING;

	do {
		status = pmbus_read_byte_data(client, 0, LTC2978_MFR_COMMON);
		if (status == -EBADMSG || status == -ENXIO) {
			/* PEC error or NACK: chip may be busy, try again */
			usleep_range(50, 100);
			continue;
		}
		if (status < 0)
			return status;

		if ((status & mask) == mask)
			return 0;

		usleep_range(50, 100);
	} while (time_before(jiffies, timeout));

	return -ETIMEDOUT;
}

static int ltc_read_word_data(struct i2c_client *client, int page, int reg)
{
	int ret;

	ret = ltc_wait_ready(client);
	if (ret < 0)
		return ret;

	return pmbus_read_word_data(client, page, reg);
}

static int ltc_read_byte_data(struct i2c_client *client, int page, int reg)
{
	int ret;

	ret = ltc_wait_ready(client);
	if (ret < 0)
		return ret;

	return pmbus_read_byte_data(client, page, reg);
}

static int ltc_write_byte(struct i2c_client *client, int page, u8 byte)
{
	int ret;

	ret = ltc_wait_ready(client);
	if (ret < 0)
		return ret;

	return pmbus_write_byte(client, page, byte);
}

static inline int lin11_to_val(int data)
{
	s16 e = ((s16)data) >> 11;
	s32 m = (((s16)(data << 5)) >> 5);

	/*
	 * mantissa is 10 bit + sign, exponent adds up to 15 bit.
	 * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
	 */
	e += 6;
	return (e < 0 ? m >> -e : m << e);
}

static int ltc_get_max(struct ltc2978_data *data, struct i2c_client *client,
		       int page, int reg, u16 *pmax)
{
	int ret;

	ret = ltc_read_word_data(client, page, reg);
	if (ret >= 0) {
		if (lin11_to_val(ret) > lin11_to_val(*pmax))
			*pmax = ret;
		ret = *pmax;
	}
	return ret;
}

static int ltc_get_min(struct ltc2978_data *data, struct i2c_client *client,
		       int page, int reg, u16 *pmin)
{
	int ret;

	ret = ltc_read_word_data(client, page, reg);
	if (ret >= 0) {
		if (lin11_to_val(ret) < lin11_to_val(*pmin))
			*pmin = ret;
		ret = *pmin;
	}
	return ret;
}

static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
					 int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_VIN_MAX:
		ret = ltc_get_max(data, client, page, LTC2978_MFR_VIN_PEAK,
				  &data->vin_max);
		break;
	case PMBUS_VIRT_READ_VOUT_MAX:
		ret = ltc_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK);
		if (ret >= 0) {
			/*
			 * VOUT is 16 bit unsigned with fixed exponent,
			 * so we can compare it directly
			 */
			if (ret > data->vout_max[page])
				data->vout_max[page] = ret;
			ret = data->vout_max[page];
		}
		break;
	case PMBUS_VIRT_READ_TEMP_MAX:
		ret = ltc_get_max(data, client, page,
				  LTC2978_MFR_TEMPERATURE_PEAK,
				  &data->temp_max[page]);
		break;
	case PMBUS_VIRT_RESET_VOUT_HISTORY:
	case PMBUS_VIRT_RESET_VIN_HISTORY:
	case PMBUS_VIRT_RESET_TEMP_HISTORY:
		ret = 0;
		break;
	default:
		ret = ltc_wait_ready(client);
		if (ret < 0)
			return ret;
		ret = -ENODATA;
		break;
	}
	return ret;
}

static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_VIN_MIN:
		ret = ltc_get_min(data, client, page, LTC2978_MFR_VIN_MIN,
				  &data->vin_min);
		break;
	case PMBUS_VIRT_READ_VOUT_MIN:
		ret = ltc_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
		if (ret >= 0) {
			/*
			 * VOUT_MIN is known to not be supported on some lots
			 * of LTC2978 revision 1, and will return the maximum
			 * possible voltage if read. If VOUT_MAX is valid and
			 * lower than the reading of VOUT_MIN, use it instead.
			 */
			if (data->vout_max[page] && ret > data->vout_max[page])
				ret = data->vout_max[page];
			if (ret < data->vout_min[page])
				data->vout_min[page] = ret;
			ret = data->vout_min[page];
		}
		break;
	case PMBUS_VIRT_READ_TEMP_MIN:
		ret = ltc_get_min(data, client, page,
				  LTC2978_MFR_TEMPERATURE_MIN,
				  &data->temp_min[page]);
		break;
	case PMBUS_VIRT_READ_IOUT_MAX:
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
	case PMBUS_VIRT_READ_TEMP2_MAX:
	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
		ret = -ENXIO;
		break;
	default:
		ret = ltc2978_read_word_data_common(client, page, reg);
		break;
	}
	return ret;
}

static int ltc2974_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_IOUT_MAX:
		ret = ltc_get_max(data, client, page, LTC2974_MFR_IOUT_PEAK,
				  &data->iout_max[page]);
		break;
	case PMBUS_VIRT_READ_IOUT_MIN:
		ret = ltc_get_min(data, client, page, LTC2974_MFR_IOUT_MIN,
				  &data->iout_min[page]);
		break;
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
		ret = 0;
		break;
	default:
		ret = ltc2978_read_word_data(client, page, reg);
		break;
	}
	return ret;
}

static int ltc2975_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_IIN_MAX:
		ret = ltc_get_max(data, client, page, LTC2975_MFR_IIN_PEAK,
				  &data->iin_max);
		break;
	case PMBUS_VIRT_READ_IIN_MIN:
		ret = ltc_get_min(data, client, page, LTC2975_MFR_IIN_MIN,
				  &data->iin_min);
		break;
	case PMBUS_VIRT_READ_PIN_MAX:
		ret = ltc_get_max(data, client, page, LTC2975_MFR_PIN_PEAK,
				  &data->pin_max);
		break;
	case PMBUS_VIRT_READ_PIN_MIN:
		ret = ltc_get_min(data, client, page, LTC2975_MFR_PIN_MIN,
				  &data->pin_min);
		break;
	case PMBUS_VIRT_RESET_IIN_HISTORY:
	case PMBUS_VIRT_RESET_PIN_HISTORY:
		ret = 0;
		break;
	default:
		ret = ltc2978_read_word_data(client, page, reg);
		break;
	}
	return ret;
}

static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_IOUT_MAX:
		ret = ltc_get_max(data, client, page, LTC3880_MFR_IOUT_PEAK,
				  &data->iout_max[page]);
		break;
	case PMBUS_VIRT_READ_TEMP2_MAX:
		ret = ltc_get_max(data, client, page,
				  LTC3880_MFR_TEMPERATURE2_PEAK,
				  &data->temp2_max);
		break;
	case PMBUS_VIRT_READ_VIN_MIN:
	case PMBUS_VIRT_READ_VOUT_MIN:
	case PMBUS_VIRT_READ_TEMP_MIN:
		ret = -ENXIO;
		break;
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
		ret = 0;
		break;
	default:
		ret = ltc2978_read_word_data_common(client, page, reg);
		break;
	}
	return ret;
}

static int ltc3883_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_IIN_MAX:
		ret = ltc_get_max(data, client, page, LTC3883_MFR_IIN_PEAK,
				  &data->iin_max);
		break;
	case PMBUS_VIRT_RESET_IIN_HISTORY:
		ret = 0;
		break;
	default:
		ret = ltc3880_read_word_data(client, page, reg);
		break;
	}
	return ret;
}

static int ltc2978_clear_peaks(struct ltc2978_data *data,
			       struct i2c_client *client, int page)
{
	int ret;

	if (has_clear_peaks(data))
		ret = ltc_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
	else
		ret = ltc_write_byte(client, page, PMBUS_CLEAR_FAULTS);

	return ret;
}

static int ltc2978_write_word_data(struct i2c_client *client, int page,
				    int reg, u16 word)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_RESET_IIN_HISTORY:
		data->iin_max = 0x7c00;
		data->iin_min = 0x7bff;
		ret = ltc2978_clear_peaks(data, client, 0);
		break;
	case PMBUS_VIRT_RESET_PIN_HISTORY:
		data->pin_max = 0x7c00;
		data->pin_min = 0x7bff;
		ret = ltc2978_clear_peaks(data, client, 0);
		break;
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
		data->iout_max[page] = 0x7c00;
		data->iout_min[page] = 0xfbff;
		ret = ltc2978_clear_peaks(data, client, page);
		break;
	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
		data->temp2_max = 0x7c00;
		ret = ltc2978_clear_peaks(data, client, page);
		break;
	case PMBUS_VIRT_RESET_VOUT_HISTORY:
		data->vout_min[page] = 0xffff;
		data->vout_max[page] = 0;
		ret = ltc2978_clear_peaks(data, client, page);
		break;
	case PMBUS_VIRT_RESET_VIN_HISTORY:
		data->vin_min = 0x7bff;
		data->vin_max = 0x7c00;
		ret = ltc2978_clear_peaks(data, client, page);
		break;
	case PMBUS_VIRT_RESET_TEMP_HISTORY:
		data->temp_min[page] = 0x7bff;
		data->temp_max[page] = 0x7c00;
		ret = ltc2978_clear_peaks(data, client, page);
		break;
	default:
		ret = ltc_wait_ready(client);
		if (ret < 0)
			return ret;
		ret = -ENODATA;
		break;
	}
	return ret;
}

static const struct i2c_device_id ltc2978_id[] = {
	{"ltc2974", ltc2974},
	{"ltc2975", ltc2975},
	{"ltc2977", ltc2977},
	{"ltc2978", ltc2978},
	{"ltc2980", ltc2980},
	{"ltc3880", ltc3880},
	{"ltc3882", ltc3882},
	{"ltc3883", ltc3883},
	{"ltc3886", ltc3886},
	{"ltc3887", ltc3887},
	{"ltm2987", ltm2987},
	{"ltm4675", ltm4675},
	{"ltm4676", ltm4676},
	{}
};
MODULE_DEVICE_TABLE(i2c, ltc2978_id);

#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
static const struct regulator_desc ltc2978_reg_desc[] = {
	PMBUS_REGULATOR("vout", 0),
	PMBUS_REGULATOR("vout", 1),
	PMBUS_REGULATOR("vout", 2),
	PMBUS_REGULATOR("vout", 3),
	PMBUS_REGULATOR("vout", 4),
	PMBUS_REGULATOR("vout", 5),
	PMBUS_REGULATOR("vout", 6),
	PMBUS_REGULATOR("vout", 7),
};
#endif /* CONFIG_SENSORS_LTC2978_REGULATOR */

static int ltc2978_get_id(struct i2c_client *client)
{
	int chip_id;

	chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
	if (chip_id < 0) {
		const struct i2c_device_id *id;
		u8 buf[I2C_SMBUS_BLOCK_MAX];
		int ret;

		if (!i2c_check_functionality(client->adapter,
					     I2C_FUNC_SMBUS_READ_BLOCK_DATA))
			return -ENODEV;

		ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
		if (ret < 0)
			return ret;
		if (ret < 3 || strncmp(buf, "LTC", 3))
			return -ENODEV;

		ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
		if (ret < 0)
			return ret;
		for (id = &ltc2978_id[0]; strlen(id->name); id++) {
			if (!strncasecmp(id->name, buf, strlen(id->name)))
				return (int)id->driver_data;
		}
		return -ENODEV;
	}

	chip_id &= LTC2978_ID_MASK;

	if (chip_id == LTC2974_ID)
		return ltc2974;
	else if (chip_id == LTC2975_ID)
		return ltc2975;
	else if (chip_id == LTC2977_ID)
		return ltc2977;
	else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2)
		return ltc2978;
	else if (chip_id == LTC2980_ID_A || chip_id == LTC2980_ID_B)
		return ltc2980;
	else if (chip_id == LTC3880_ID)
		return ltc3880;
	else if (chip_id == LTC3882_ID || chip_id == LTC3882_ID_D1)
		return ltc3882;
	else if (chip_id == LTC3883_ID)
		return ltc3883;
	else if (chip_id == LTC3886_ID)
		return ltc3886;
	else if (chip_id == LTC3887_ID)
		return ltc3887;
	else if (chip_id == LTM2987_ID_A || chip_id == LTM2987_ID_B)
		return ltm2987;
	else if (chip_id == LTM4675_ID)
		return ltm4675;
	else if (chip_id == LTM4676_ID_REV1 || chip_id == LTM4676_ID_REV2 ||
		 chip_id == LTM4676A_ID)
		return ltm4676;

	dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
	return -ENODEV;
}

static int ltc2978_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	int i, chip_id;
	struct ltc2978_data *data;
	struct pmbus_driver_info *info;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -ENODEV;

	data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	chip_id = ltc2978_get_id(client);
	if (chip_id < 0)
		return chip_id;

	data->id = chip_id;
	if (data->id != id->driver_data)
		dev_warn(&client->dev,
			 "Device mismatch: Configured %s, detected %s\n",
			 id->name,
			 ltc2978_id[data->id].name);

	info = &data->info;
	info->write_word_data = ltc2978_write_word_data;
	info->write_byte = ltc_write_byte;
	info->read_word_data = ltc_read_word_data;
	info->read_byte_data = ltc_read_byte_data;

	data->vin_min = 0x7bff;
	data->vin_max = 0x7c00;
	for (i = 0; i < ARRAY_SIZE(data->vout_min); i++)
		data->vout_min[i] = 0xffff;
	for (i = 0; i < ARRAY_SIZE(data->iout_min); i++)
		data->iout_min[i] = 0xfbff;
	for (i = 0; i < ARRAY_SIZE(data->iout_max); i++)
		data->iout_max[i] = 0x7c00;
	for (i = 0; i < ARRAY_SIZE(data->temp_min); i++)
		data->temp_min[i] = 0x7bff;
	for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
		data->temp_max[i] = 0x7c00;
	data->temp2_max = 0x7c00;

	switch (data->id) {
	case ltc2974:
		info->read_word_data = ltc2974_read_word_data;
		info->pages = LTC2974_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_TEMP2;
		for (i = 0; i < info->pages; i++) {
			info->func[i] |= PMBUS_HAVE_VOUT
			  | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
			  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
			  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
		}
		break;
	case ltc2975:
		info->read_word_data = ltc2975_read_word_data;
		info->pages = LTC2974_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
		  | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_TEMP2;
		for (i = 0; i < info->pages; i++) {
			info->func[i] |= PMBUS_HAVE_VOUT
			  | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
			  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
			  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
		}
		break;
	case ltc2977:
	case ltc2978:
	case ltc2980:
	case ltm2987:
		info->read_word_data = ltc2978_read_word_data;
		info->pages = LTC2978_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
		for (i = 1; i < LTC2978_NUM_PAGES; i++) {
			info->func[i] = PMBUS_HAVE_VOUT
			  | PMBUS_HAVE_STATUS_VOUT;
		}
		break;
	case ltc3880:
	case ltc3887:
	case ltm4675:
	case ltm4676:
		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
		info->read_word_data = ltc3880_read_word_data;
		info->pages = LTC3880_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
		  | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_POUT
		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
		break;
	case ltc3882:
		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
		info->read_word_data = ltc3880_read_word_data;
		info->pages = LTC3880_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_VIN
		  | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_POUT
		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
		break;
	case ltc3883:
		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
		info->read_word_data = ltc3883_read_word_data;
		info->pages = LTC3883_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
		  | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
		break;
	case ltc3886:
		data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
		info->read_word_data = ltc3883_read_word_data;
		info->pages = LTC3880_NUM_PAGES;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
		  | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_POUT
		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
		break;
	default:
		return -ENODEV;
	}

#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
	info->num_regulators = info->pages;
	info->reg_desc = ltc2978_reg_desc;
	if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
		dev_err(&client->dev, "num_regulators too large!");
		info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
	}
#endif

	return pmbus_do_probe(client, id, info);
}

#ifdef CONFIG_OF
static const struct of_device_id ltc2978_of_match[] = {
	{ .compatible = "lltc,ltc2974" },
	{ .compatible = "lltc,ltc2975" },
	{ .compatible = "lltc,ltc2977" },
	{ .compatible = "lltc,ltc2978" },
	{ .compatible = "lltc,ltc2980" },
	{ .compatible = "lltc,ltc3880" },
	{ .compatible = "lltc,ltc3882" },
	{ .compatible = "lltc,ltc3883" },
	{ .compatible = "lltc,ltc3886" },
	{ .compatible = "lltc,ltc3887" },
	{ .compatible = "lltc,ltm2987" },
	{ .compatible = "lltc,ltm4675" },
	{ .compatible = "lltc,ltm4676" },
	{ }
};
MODULE_DEVICE_TABLE(of, ltc2978_of_match);
#endif

static struct i2c_driver ltc2978_driver = {
	.driver = {
		   .name = "ltc2978",
		   .of_match_table = of_match_ptr(ltc2978_of_match),
		   },
	.probe = ltc2978_probe,
	.remove = pmbus_do_remove,
	.id_table = ltc2978_id,
};

module_i2c_driver(ltc2978_driver);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for LTC2978 and comppatible chips");
MODULE_LICENSE("GPL");