aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/tmp513.c
blob: df66e0bc1253967919b41a0022f3d594300a0b3f (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for Texas Instruments TMP512, TMP513 power monitor chips
 *
 * TMP513:
 * Thermal/Power Management with Triple Remote and
 * Local Temperature Sensor and Current Shunt Monitor
 * Datasheet: http://www.ti.com/lit/gpn/tmp513
 *
 * TMP512:
 * Thermal/Power Management with Dual Remote
 *	and Local Temperature Sensor and Current Shunt Monitor
 * Datasheet: http://www.ti.com/lit/gpn/tmp512
 *
 * Copyright (C) 2019 Eric Tremblay <etremblay@distech-controls.com>
 *
 * 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; version 2 of the License.
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/util_macros.h>

// Common register definition
#define TMP51X_SHUNT_CONFIG		0x00
#define TMP51X_TEMP_CONFIG		0x01
#define TMP51X_STATUS			0x02
#define TMP51X_SMBUS_ALERT		0x03
#define TMP51X_SHUNT_CURRENT_RESULT	0x04
#define TMP51X_BUS_VOLTAGE_RESULT	0x05
#define TMP51X_POWER_RESULT		0x06
#define TMP51X_BUS_CURRENT_RESULT	0x07
#define TMP51X_LOCAL_TEMP_RESULT	0x08
#define TMP51X_REMOTE_TEMP_RESULT_1	0x09
#define TMP51X_REMOTE_TEMP_RESULT_2	0x0A
#define TMP51X_SHUNT_CURRENT_H_LIMIT	0x0C
#define TMP51X_SHUNT_CURRENT_L_LIMIT	0x0D
#define TMP51X_BUS_VOLTAGE_H_LIMIT	0x0E
#define TMP51X_BUS_VOLTAGE_L_LIMIT	0x0F
#define TMP51X_POWER_LIMIT		0x10
#define TMP51X_LOCAL_TEMP_LIMIT	0x11
#define TMP51X_REMOTE_TEMP_LIMIT_1	0x12
#define TMP51X_REMOTE_TEMP_LIMIT_2	0x13
#define TMP51X_SHUNT_CALIBRATION	0x15
#define TMP51X_N_FACTOR_AND_HYST_1	0x16
#define TMP51X_N_FACTOR_2		0x17
#define TMP51X_MAN_ID_REG		0xFE
#define TMP51X_DEVICE_ID_REG		0xFF

// TMP513 specific register definition
#define TMP513_REMOTE_TEMP_RESULT_3	0x0B
#define TMP513_REMOTE_TEMP_LIMIT_3	0x14
#define TMP513_N_FACTOR_3		0x18

// Common attrs, and NULL
#define TMP51X_MANUFACTURER_ID		0x55FF

#define TMP512_DEVICE_ID		0x22FF
#define TMP513_DEVICE_ID		0x23FF

// Default config
#define TMP51X_SHUNT_CONFIG_DEFAULT	0x399F
#define TMP51X_SHUNT_VALUE_DEFAULT	1000
#define TMP51X_VBUS_RANGE_DEFAULT	TMP51X_VBUS_RANGE_32V
#define TMP51X_PGA_DEFAULT		8
#define TMP51X_MAX_REGISTER_ADDR	0xFF

#define TMP512_TEMP_CONFIG_DEFAULT	0xBF80
#define TMP513_TEMP_CONFIG_DEFAULT	0xFF80

// Mask and shift
#define CURRENT_SENSE_VOLTAGE_320_MASK	0x1800
#define CURRENT_SENSE_VOLTAGE_160_MASK	0x1000
#define CURRENT_SENSE_VOLTAGE_80_MASK	0x0800
#define CURRENT_SENSE_VOLTAGE_40_MASK	0

#define TMP51X_BUS_VOLTAGE_MASK		0x2000
#define TMP51X_NFACTOR_MASK		0xFF00
#define TMP51X_HYST_MASK		0x00FF

#define TMP51X_BUS_VOLTAGE_SHIFT	3
#define TMP51X_TEMP_SHIFT		3

// Alarms
#define TMP51X_SHUNT_CURRENT_H_LIMIT_POS	15
#define TMP51X_SHUNT_CURRENT_L_LIMIT_POS	14
#define TMP51X_BUS_VOLTAGE_H_LIMIT_POS		13
#define TMP51X_BUS_VOLTAGE_L_LIMIT_POS		12
#define TMP51X_POWER_LIMIT_POS			11
#define TMP51X_LOCAL_TEMP_LIMIT_POS		10
#define TMP51X_REMOTE_TEMP_LIMIT_1_POS		9
#define TMP51X_REMOTE_TEMP_LIMIT_2_POS		8
#define TMP513_REMOTE_TEMP_LIMIT_3_POS		7

#define TMP51X_VBUS_RANGE_32V		32000000
#define TMP51X_VBUS_RANGE_16V		16000000

// Max and Min value
#define MAX_BUS_VOLTAGE_32_LIMIT	32764
#define MAX_BUS_VOLTAGE_16_LIMIT	16382

// Max possible value is -256 to +256 but datasheet indicated -40 to 125.
#define MAX_TEMP_LIMIT			125000
#define MIN_TEMP_LIMIT			-40000

#define MAX_TEMP_HYST			127500

static const u8 TMP51X_TEMP_INPUT[4] = {
	TMP51X_LOCAL_TEMP_RESULT,
	TMP51X_REMOTE_TEMP_RESULT_1,
	TMP51X_REMOTE_TEMP_RESULT_2,
	TMP513_REMOTE_TEMP_RESULT_3
};

static const u8 TMP51X_TEMP_CRIT[4] = {
	TMP51X_LOCAL_TEMP_LIMIT,
	TMP51X_REMOTE_TEMP_LIMIT_1,
	TMP51X_REMOTE_TEMP_LIMIT_2,
	TMP513_REMOTE_TEMP_LIMIT_3
};

static const u8 TMP51X_TEMP_CRIT_ALARM[4] = {
	TMP51X_LOCAL_TEMP_LIMIT_POS,
	TMP51X_REMOTE_TEMP_LIMIT_1_POS,
	TMP51X_REMOTE_TEMP_LIMIT_2_POS,
	TMP513_REMOTE_TEMP_LIMIT_3_POS
};

static const u8 TMP51X_TEMP_CRIT_HYST[4] = {
	TMP51X_N_FACTOR_AND_HYST_1,
	TMP51X_N_FACTOR_AND_HYST_1,
	TMP51X_N_FACTOR_AND_HYST_1,
	TMP51X_N_FACTOR_AND_HYST_1
};

static const u8 TMP51X_CURR_INPUT[2] = {
	TMP51X_SHUNT_CURRENT_RESULT,
	TMP51X_BUS_CURRENT_RESULT
};

static struct regmap_config tmp51x_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = TMP51X_MAX_REGISTER_ADDR,
};

enum tmp51x_ids {
	tmp512, tmp513
};

struct tmp51x_data {
	u16 shunt_config;
	u16 pga_gain;
	u32 vbus_range_uvolt;

	u16 temp_config;
	u32 nfactor[3];

	u32 shunt_uohms;

	u32 curr_lsb_ua;
	u32 pwr_lsb_uw;

	enum tmp51x_ids id;
	struct regmap *regmap;
};

// Set the shift based on the gain 8=4, 4=3, 2=2, 1=1
static inline u8 tmp51x_get_pga_shift(struct tmp51x_data *data)
{
	return 5 - ffs(data->pga_gain);
}

static int tmp51x_get_value(struct tmp51x_data *data, u8 reg, u8 pos,
			    unsigned int regval, long *val)
{
	switch (reg) {
	case TMP51X_STATUS:
		*val = (regval >> pos) & 1;
		break;
	case TMP51X_SHUNT_CURRENT_RESULT:
	case TMP51X_SHUNT_CURRENT_H_LIMIT:
	case TMP51X_SHUNT_CURRENT_L_LIMIT:
		/*
		 * The valus is read in voltage in the chip but reported as
		 * current to the user.
		 * 2's compliment number shifted by one to four depending
		 * on the pga gain setting. 1lsb = 10uV
		 */
		*val = sign_extend32(regval, 17 - tmp51x_get_pga_shift(data));
		*val = DIV_ROUND_CLOSEST(*val * 10000, data->shunt_uohms);
		break;
	case TMP51X_BUS_VOLTAGE_RESULT:
	case TMP51X_BUS_VOLTAGE_H_LIMIT:
	case TMP51X_BUS_VOLTAGE_L_LIMIT:
		// 1lsb = 4mV
		*val = (regval >> TMP51X_BUS_VOLTAGE_SHIFT) * 4;
		break;
	case TMP51X_POWER_RESULT:
	case TMP51X_POWER_LIMIT:
		// Power = (current * BusVoltage) / 5000
		*val = regval * data->pwr_lsb_uw;
		break;
	case TMP51X_BUS_CURRENT_RESULT:
		// Current = (ShuntVoltage * CalibrationRegister) / 4096
		*val = sign_extend32(regval, 16) * data->curr_lsb_ua;
		*val = DIV_ROUND_CLOSEST(*val, 1000);
		break;
	case TMP51X_LOCAL_TEMP_RESULT:
	case TMP51X_REMOTE_TEMP_RESULT_1:
	case TMP51X_REMOTE_TEMP_RESULT_2:
	case TMP513_REMOTE_TEMP_RESULT_3:
	case TMP51X_LOCAL_TEMP_LIMIT:
	case TMP51X_REMOTE_TEMP_LIMIT_1:
	case TMP51X_REMOTE_TEMP_LIMIT_2:
	case TMP513_REMOTE_TEMP_LIMIT_3:
		// 1lsb = 0.0625 degrees centigrade
		*val = sign_extend32(regval, 16) >> TMP51X_TEMP_SHIFT;
		*val = DIV_ROUND_CLOSEST(*val * 625, 10);
		break;
	case TMP51X_N_FACTOR_AND_HYST_1:
		// 1lsb = 0.5 degrees centigrade
		*val = (regval & TMP51X_HYST_MASK) * 500;
		break;
	default:
		// Programmer goofed
		WARN_ON_ONCE(1);
		*val = 0;
		return -EOPNOTSUPP;
	}

	return 0;
}

static int tmp51x_set_value(struct tmp51x_data *data, u8 reg, long val)
{
	int regval, max_val;
	u32 mask = 0;

	switch (reg) {
	case TMP51X_SHUNT_CURRENT_H_LIMIT:
	case TMP51X_SHUNT_CURRENT_L_LIMIT:
		/*
		 * The user enter current value and we convert it to
		 * voltage. 1lsb = 10uV
		 */
		val = DIV_ROUND_CLOSEST(val * data->shunt_uohms, 10000);
		max_val = U16_MAX >> tmp51x_get_pga_shift(data);
		regval = clamp_val(val, -max_val, max_val);
		break;
	case TMP51X_BUS_VOLTAGE_H_LIMIT:
	case TMP51X_BUS_VOLTAGE_L_LIMIT:
		// 1lsb = 4mV
		max_val = (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_32V) ?
			MAX_BUS_VOLTAGE_32_LIMIT : MAX_BUS_VOLTAGE_16_LIMIT;

		val = clamp_val(DIV_ROUND_CLOSEST(val, 4), 0, max_val);
		regval = val << TMP51X_BUS_VOLTAGE_SHIFT;
		break;
	case TMP51X_POWER_LIMIT:
		regval = clamp_val(DIV_ROUND_CLOSEST(val, data->pwr_lsb_uw), 0,
				   U16_MAX);
		break;
	case TMP51X_LOCAL_TEMP_LIMIT:
	case TMP51X_REMOTE_TEMP_LIMIT_1:
	case TMP51X_REMOTE_TEMP_LIMIT_2:
	case TMP513_REMOTE_TEMP_LIMIT_3:
		// 1lsb = 0.0625 degrees centigrade
		val = clamp_val(val, MIN_TEMP_LIMIT, MAX_TEMP_LIMIT);
		regval = DIV_ROUND_CLOSEST(val * 10, 625) << TMP51X_TEMP_SHIFT;
		break;
	case TMP51X_N_FACTOR_AND_HYST_1:
		// 1lsb = 0.5 degrees centigrade
		val = clamp_val(val, 0, MAX_TEMP_HYST);
		regval = DIV_ROUND_CLOSEST(val, 500);
		mask = TMP51X_HYST_MASK;
		break;
	default:
		// Programmer goofed
		WARN_ON_ONCE(1);
		return -EOPNOTSUPP;
	}

	if (mask == 0)
		return regmap_write(data->regmap, reg, regval);
	else
		return regmap_update_bits(data->regmap, reg, mask, regval);
}

static u8 tmp51x_get_reg(enum hwmon_sensor_types type, u32 attr, int channel)
{
	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_input:
			return TMP51X_TEMP_INPUT[channel];
		case hwmon_temp_crit_alarm:
			return TMP51X_STATUS;
		case hwmon_temp_crit:
			return TMP51X_TEMP_CRIT[channel];
		case hwmon_temp_crit_hyst:
			return TMP51X_TEMP_CRIT_HYST[channel];
		}
		break;
	case hwmon_in:
		switch (attr) {
		case hwmon_in_input:
			return TMP51X_BUS_VOLTAGE_RESULT;
		case hwmon_in_lcrit_alarm:
		case hwmon_in_crit_alarm:
			return TMP51X_STATUS;
		case hwmon_in_lcrit:
			return TMP51X_BUS_VOLTAGE_L_LIMIT;
		case hwmon_in_crit:
			return TMP51X_BUS_VOLTAGE_H_LIMIT;
		}
		break;
	case hwmon_curr:
		switch (attr) {
		case hwmon_curr_input:
			return TMP51X_CURR_INPUT[channel];
		case hwmon_curr_lcrit_alarm:
		case hwmon_curr_crit_alarm:
			return TMP51X_STATUS;
		case hwmon_curr_lcrit:
			return TMP51X_SHUNT_CURRENT_L_LIMIT;
		case hwmon_curr_crit:
			return TMP51X_SHUNT_CURRENT_H_LIMIT;
		}
		break;
	case hwmon_power:
		switch (attr) {
		case hwmon_power_input:
			return TMP51X_POWER_RESULT;
		case hwmon_power_crit_alarm:
			return TMP51X_STATUS;
		case hwmon_power_crit:
			return TMP51X_POWER_LIMIT;
		}
		break;
	default:
		break;
	}

	return 0;
}

static u8 tmp51x_get_status_pos(enum hwmon_sensor_types type, u32 attr,
				int channel)
{
	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_crit_alarm:
			return TMP51X_TEMP_CRIT_ALARM[channel];
		}
		break;
	case hwmon_in:
		switch (attr) {
		case hwmon_in_lcrit_alarm:
			return TMP51X_BUS_VOLTAGE_L_LIMIT_POS;
		case hwmon_in_crit_alarm:
			return TMP51X_BUS_VOLTAGE_H_LIMIT_POS;
		}
		break;
	case hwmon_curr:
		switch (attr) {
		case hwmon_curr_lcrit_alarm:
			return TMP51X_SHUNT_CURRENT_L_LIMIT_POS;
		case hwmon_curr_crit_alarm:
			return TMP51X_SHUNT_CURRENT_H_LIMIT_POS;
		}
		break;
	case hwmon_power:
		switch (attr) {
		case hwmon_power_crit_alarm:
			return TMP51X_POWER_LIMIT_POS;
		}
		break;
	default:
		break;
	}

	return 0;
}

static int tmp51x_read(struct device *dev, enum hwmon_sensor_types type,
		       u32 attr, int channel, long *val)
{
	struct tmp51x_data *data = dev_get_drvdata(dev);
	int ret;
	u32 regval;
	u8 pos = 0, reg = 0;

	reg = tmp51x_get_reg(type, attr, channel);
	if (reg == 0)
		return -EOPNOTSUPP;

	if (reg == TMP51X_STATUS)
		pos = tmp51x_get_status_pos(type, attr, channel);

	ret = regmap_read(data->regmap, reg, &regval);
	if (ret < 0)
		return ret;

	return tmp51x_get_value(data, reg, pos, regval, val);
}

static int tmp51x_write(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long val)
{
	u8 reg = 0;

	reg = tmp51x_get_reg(type, attr, channel);
	if (reg == 0)
		return -EOPNOTSUPP;

	return tmp51x_set_value(dev_get_drvdata(dev), reg, val);
}

static umode_t tmp51x_is_visible(const void *_data,
				 enum hwmon_sensor_types type, u32 attr,
				 int channel)
{
	const struct tmp51x_data *data = _data;

	switch (type) {
	case hwmon_temp:
		if (data->id == tmp512 && channel == 4)
			return 0;
		switch (attr) {
		case hwmon_temp_input:
		case hwmon_temp_crit_alarm:
			return 0444;
		case hwmon_temp_crit:
			return 0644;
		case hwmon_temp_crit_hyst:
			if (channel == 0)
				return 0644;
			return 0444;
		}
		break;
	case hwmon_in:
		switch (attr) {
		case hwmon_in_input:
		case hwmon_in_lcrit_alarm:
		case hwmon_in_crit_alarm:
			return 0444;
		case hwmon_in_lcrit:
		case hwmon_in_crit:
			return 0644;
		}
		break;
	case hwmon_curr:
		if (!data->shunt_uohms)
			return 0;

		switch (attr) {
		case hwmon_curr_input:
		case hwmon_curr_lcrit_alarm:
		case hwmon_curr_crit_alarm:
			return 0444;
		case hwmon_curr_lcrit:
		case hwmon_curr_crit:
			return 0644;
		}
		break;
	case hwmon_power:
		if (!data->shunt_uohms)
			return 0;

		switch (attr) {
		case hwmon_power_input:
		case hwmon_power_crit_alarm:
			return 0444;
		case hwmon_power_crit:
			return 0644;
		}
		break;
	default:
		break;
	}
	return 0;
}

static const struct hwmon_channel_info *tmp51x_info[] = {
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
			   HWMON_T_CRIT_HYST,
			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
			   HWMON_T_CRIT_HYST,
			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
			   HWMON_T_CRIT_HYST,
			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
			   HWMON_T_CRIT_HYST),
	HWMON_CHANNEL_INFO(in,
			   HWMON_I_INPUT | HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM |
			   HWMON_I_CRIT | HWMON_I_CRIT_ALARM),
	HWMON_CHANNEL_INFO(curr,
			   HWMON_C_INPUT | HWMON_C_LCRIT | HWMON_C_LCRIT_ALARM |
			   HWMON_C_CRIT | HWMON_C_CRIT_ALARM,
			   HWMON_C_INPUT),
	HWMON_CHANNEL_INFO(power,
			   HWMON_P_INPUT | HWMON_P_CRIT | HWMON_P_CRIT_ALARM),
	NULL
};

static const struct hwmon_ops tmp51x_hwmon_ops = {
	.is_visible = tmp51x_is_visible,
	.read = tmp51x_read,
	.write = tmp51x_write,
};

static const struct hwmon_chip_info tmp51x_chip_info = {
	.ops = &tmp51x_hwmon_ops,
	.info = tmp51x_info,
};

/*
 * Calibrate the tmp51x following the datasheet method
 */
static int tmp51x_calibrate(struct tmp51x_data *data)
{
	int vshunt_max = data->pga_gain * 40;
	u64 max_curr_ma;
	u32 div;

	/*
	 * If shunt_uohms is equal to 0, the calibration should be set to 0.
	 * The consequence will be that the current and power measurement engine
	 * of the sensor will not work. Temperature and voltage sensing will
	 * continue to work.
	 */
	if (data->shunt_uohms == 0)
		return regmap_write(data->regmap, TMP51X_SHUNT_CALIBRATION, 0);

	max_curr_ma = DIV_ROUND_CLOSEST_ULL(vshunt_max * 1000 * 1000,
					    data->shunt_uohms);

	/*
	 * Calculate the minimal bit resolution for the current and the power.
	 * Those values will be used during register interpretation.
	 */
	data->curr_lsb_ua = DIV_ROUND_CLOSEST_ULL(max_curr_ma * 1000, 32767);
	data->pwr_lsb_uw = 20 * data->curr_lsb_ua;

	div = DIV_ROUND_CLOSEST_ULL(data->curr_lsb_ua * data->shunt_uohms,
				    1000 * 1000);

	return regmap_write(data->regmap, TMP51X_SHUNT_CALIBRATION,
			    DIV_ROUND_CLOSEST(40960, div));
}

/*
 * Initialize the configuration and calibration registers.
 */
static int tmp51x_init(struct tmp51x_data *data)
{
	unsigned int regval;
	int ret = regmap_write(data->regmap, TMP51X_SHUNT_CONFIG,
			       data->shunt_config);
	if (ret < 0)
		return ret;

	ret = regmap_write(data->regmap, TMP51X_TEMP_CONFIG, data->temp_config);
	if (ret < 0)
		return ret;

	// nFactor configuration
	ret = regmap_update_bits(data->regmap, TMP51X_N_FACTOR_AND_HYST_1,
				 TMP51X_NFACTOR_MASK, data->nfactor[0] << 8);
	if (ret < 0)
		return ret;

	ret = regmap_write(data->regmap, TMP51X_N_FACTOR_2,
			   data->nfactor[1] << 8);
	if (ret < 0)
		return ret;

	if (data->id == tmp513) {
		ret = regmap_write(data->regmap, TMP513_N_FACTOR_3,
				   data->nfactor[2] << 8);
		if (ret < 0)
			return ret;
	}

	ret = tmp51x_calibrate(data);
	if (ret < 0)
		return ret;

	// Read the status register before using as the datasheet propose
	return regmap_read(data->regmap, TMP51X_STATUS, &regval);
}

static const struct i2c_device_id tmp51x_id[] = {
	{ "tmp512", tmp512 },
	{ "tmp513", tmp513 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, tmp51x_id);

static const struct of_device_id tmp51x_of_match[] = {
	{
		.compatible = "ti,tmp512",
		.data = (void *)tmp512
	},
	{
		.compatible = "ti,tmp513",
		.data = (void *)tmp513
	},
	{ },
};
MODULE_DEVICE_TABLE(of, tmp51x_of_match);

static int tmp51x_vbus_range_to_reg(struct device *dev,
				    struct tmp51x_data *data)
{
	if (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_32V) {
		data->shunt_config |= TMP51X_BUS_VOLTAGE_MASK;
	} else if (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_16V) {
		data->shunt_config &= ~TMP51X_BUS_VOLTAGE_MASK;
	} else {
		dev_err(dev, "ti,bus-range-microvolt is invalid: %u\n",
			data->vbus_range_uvolt);
		return -EINVAL;
	}
	return 0;
}

static int tmp51x_pga_gain_to_reg(struct device *dev, struct tmp51x_data *data)
{
	if (data->pga_gain == 8) {
		data->shunt_config |= CURRENT_SENSE_VOLTAGE_320_MASK;
	} else if (data->pga_gain == 4) {
		data->shunt_config |= CURRENT_SENSE_VOLTAGE_160_MASK;
	} else if (data->pga_gain == 2) {
		data->shunt_config |= CURRENT_SENSE_VOLTAGE_80_MASK;
	} else if (data->pga_gain == 1) {
		data->shunt_config |= CURRENT_SENSE_VOLTAGE_40_MASK;
	} else {
		dev_err(dev, "ti,pga-gain is invalid: %u\n", data->pga_gain);
		return -EINVAL;
	}
	return 0;
}

static int tmp51x_read_properties(struct device *dev, struct tmp51x_data *data)
{
	int ret;
	u32 nfactor[3];
	u32 val;

	ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
	data->shunt_uohms = (ret >= 0) ? val : TMP51X_SHUNT_VALUE_DEFAULT;

	ret = device_property_read_u32(dev, "ti,bus-range-microvolt", &val);
	data->vbus_range_uvolt = (ret >= 0) ? val : TMP51X_VBUS_RANGE_DEFAULT;
	ret = tmp51x_vbus_range_to_reg(dev, data);
	if (ret < 0)
		return ret;

	ret = device_property_read_u32(dev, "ti,pga-gain", &val);
	data->pga_gain = (ret >= 0) ? val : TMP51X_PGA_DEFAULT;
	ret = tmp51x_pga_gain_to_reg(dev, data);
	if (ret < 0)
		return ret;

	ret = device_property_read_u32_array(dev, "ti,nfactor", nfactor,
					    (data->id == tmp513) ? 3 : 2);
	if (ret >= 0)
		memcpy(data->nfactor, nfactor, (data->id == tmp513) ? 3 : 2);

	// Check if shunt value is compatible with pga-gain
	if (data->shunt_uohms > data->pga_gain * 40 * 1000 * 1000) {
		dev_err(dev, "shunt-resistor: %u too big for pga_gain: %u\n",
			data->shunt_uohms, data->pga_gain);
		return -EINVAL;
	}

	return 0;
}

static void tmp51x_use_default(struct tmp51x_data *data)
{
	data->vbus_range_uvolt = TMP51X_VBUS_RANGE_DEFAULT;
	data->pga_gain = TMP51X_PGA_DEFAULT;
	data->shunt_uohms = TMP51X_SHUNT_VALUE_DEFAULT;
}

static int tmp51x_configure(struct device *dev, struct tmp51x_data *data)
{
	data->shunt_config = TMP51X_SHUNT_CONFIG_DEFAULT;
	data->temp_config = (data->id == tmp513) ?
			TMP513_TEMP_CONFIG_DEFAULT : TMP512_TEMP_CONFIG_DEFAULT;

	if (dev->of_node)
		return tmp51x_read_properties(dev, data);

	tmp51x_use_default(data);

	return 0;
}

static int tmp51x_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct tmp51x_data *data;
	struct device *hwmon_dev;
	int ret;

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

	if (client->dev.of_node)
		data->id = (enum tmp51x_ids)device_get_match_data(&client->dev);
	else
		data->id = id->driver_data;

	ret = tmp51x_configure(dev, data);
	if (ret < 0) {
		dev_err(dev, "error configuring the device: %d\n", ret);
		return ret;
	}

	data->regmap = devm_regmap_init_i2c(client, &tmp51x_regmap_config);
	if (IS_ERR(data->regmap)) {
		dev_err(dev, "failed to allocate register map\n");
		return PTR_ERR(data->regmap);
	}

	ret = tmp51x_init(data);
	if (ret < 0) {
		dev_err(dev, "error configuring the device: %d\n", ret);
		return -ENODEV;
	}

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 data,
							 &tmp51x_chip_info,
							 NULL);
	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

	dev_dbg(dev, "power monitor %s\n", id->name);

	return 0;
}

static struct i2c_driver tmp51x_driver = {
	.driver = {
		.name	= "tmp51x",
		.of_match_table = of_match_ptr(tmp51x_of_match),
	},
	.probe		= tmp51x_probe,
	.id_table	= tmp51x_id,
};

module_i2c_driver(tmp51x_driver);

MODULE_AUTHOR("Eric Tremblay <etremblay@distechcontrols.com>");
MODULE_DESCRIPTION("tmp51x driver");
MODULE_LICENSE("GPL");