summaryrefslogtreecommitdiffstats
path: root/drivers/power/max77693_charger.c
blob: 754879eb59f67b878fc70b6b19dc10935c15d257 (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
/*
 * max77693_charger.c - Battery charger driver for the Maxim 77693
 *
 * Copyright (C) 2014 Samsung Electronics
 * Krzysztof Kozlowski <k.kozlowski@samsung.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; 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/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>
#include <linux/mfd/max77693.h>
#include <linux/mfd/max77693-private.h>

#define MAX77693_CHARGER_NAME				"max77693-charger"
static const char *max77693_charger_model		= "MAX77693";
static const char *max77693_charger_manufacturer	= "Maxim Integrated";

struct max77693_charger {
	struct device		*dev;
	struct max77693_dev	*max77693;
	struct power_supply	*charger;

	u32 constant_volt;
	u32 min_system_volt;
	u32 thermal_regulation_temp;
	u32 batttery_overcurrent;
	u32 charge_input_threshold_volt;
};

static int max77693_get_charger_state(struct regmap *regmap, int *val)
{
	int ret;
	unsigned int data;

	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data);
	if (ret < 0)
		return ret;

	data &= CHG_DETAILS_01_CHG_MASK;
	data >>= CHG_DETAILS_01_CHG_SHIFT;

	switch (data) {
	case MAX77693_CHARGING_PREQUALIFICATION:
	case MAX77693_CHARGING_FAST_CONST_CURRENT:
	case MAX77693_CHARGING_FAST_CONST_VOLTAGE:
	case MAX77693_CHARGING_TOP_OFF:
	/* In high temp the charging current is reduced, but still charging */
	case MAX77693_CHARGING_HIGH_TEMP:
		*val = POWER_SUPPLY_STATUS_CHARGING;
		break;
	case MAX77693_CHARGING_DONE:
		*val = POWER_SUPPLY_STATUS_FULL;
		break;
	case MAX77693_CHARGING_TIMER_EXPIRED:
	case MAX77693_CHARGING_THERMISTOR_SUSPEND:
		*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
		break;
	case MAX77693_CHARGING_OFF:
	case MAX77693_CHARGING_OVER_TEMP:
	case MAX77693_CHARGING_WATCHDOG_EXPIRED:
		*val = POWER_SUPPLY_STATUS_DISCHARGING;
		break;
	case MAX77693_CHARGING_RESERVED:
	default:
		*val = POWER_SUPPLY_STATUS_UNKNOWN;
	}

	return 0;
}

static int max77693_get_charge_type(struct regmap *regmap, int *val)
{
	int ret;
	unsigned int data;

	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data);
	if (ret < 0)
		return ret;

	data &= CHG_DETAILS_01_CHG_MASK;
	data >>= CHG_DETAILS_01_CHG_SHIFT;

	switch (data) {
	case MAX77693_CHARGING_PREQUALIFICATION:
	/*
	 * Top-off: trickle or fast? In top-off the current varies between
	 * 100 and 250 mA. It is higher than prequalification current.
	 */
	case MAX77693_CHARGING_TOP_OFF:
		*val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
		break;
	case MAX77693_CHARGING_FAST_CONST_CURRENT:
	case MAX77693_CHARGING_FAST_CONST_VOLTAGE:
	/* In high temp the charging current is reduced, but still charging */
	case MAX77693_CHARGING_HIGH_TEMP:
		*val = POWER_SUPPLY_CHARGE_TYPE_FAST;
		break;
	case MAX77693_CHARGING_DONE:
	case MAX77693_CHARGING_TIMER_EXPIRED:
	case MAX77693_CHARGING_THERMISTOR_SUSPEND:
	case MAX77693_CHARGING_OFF:
	case MAX77693_CHARGING_OVER_TEMP:
	case MAX77693_CHARGING_WATCHDOG_EXPIRED:
		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
		break;
	case MAX77693_CHARGING_RESERVED:
	default:
		*val = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
	}

	return 0;
}

/*
 * Supported health statuses:
 *  - POWER_SUPPLY_HEALTH_DEAD
 *  - POWER_SUPPLY_HEALTH_GOOD
 *  - POWER_SUPPLY_HEALTH_OVERVOLTAGE
 *  - POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE
 *  - POWER_SUPPLY_HEALTH_UNKNOWN
 *  - POWER_SUPPLY_HEALTH_UNSPEC_FAILURE
 */
static int max77693_get_battery_health(struct regmap *regmap, int *val)
{
	int ret;
	unsigned int data;

	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data);
	if (ret < 0)
		return ret;

	data &= CHG_DETAILS_01_BAT_MASK;
	data >>= CHG_DETAILS_01_BAT_SHIFT;

	switch (data) {
	case MAX77693_BATTERY_NOBAT:
		*val = POWER_SUPPLY_HEALTH_DEAD;
		break;
	case MAX77693_BATTERY_PREQUALIFICATION:
	case MAX77693_BATTERY_GOOD:
	case MAX77693_BATTERY_LOWVOLTAGE:
		*val = POWER_SUPPLY_HEALTH_GOOD;
		break;
	case MAX77693_BATTERY_TIMER_EXPIRED:
		/*
		 * Took longer to charge than expected, charging suspended.
		 * Damaged battery?
		 */
		*val = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
		break;
	case MAX77693_BATTERY_OVERVOLTAGE:
		*val = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
		break;
	case MAX77693_BATTERY_OVERCURRENT:
		*val = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
		break;
	case MAX77693_BATTERY_RESERVED:
	default:
		*val = POWER_SUPPLY_HEALTH_UNKNOWN;
		break;
	}

	return 0;
}

static int max77693_get_present(struct regmap *regmap, int *val)
{
	unsigned int data;
	int ret;

	/*
	 * Read CHG_INT_OK register. High DETBAT bit here should be
	 * equal to value 0x0 in CHG_DETAILS_01/BAT field.
	 */
	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_INT_OK, &data);
	if (ret < 0)
		return ret;

	*val = (data & CHG_INT_OK_DETBAT_MASK) ? 0 : 1;

	return 0;
}

static int max77693_get_online(struct regmap *regmap, int *val)
{
	unsigned int data;
	int ret;

	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_INT_OK, &data);
	if (ret < 0)
		return ret;

	*val = (data & CHG_INT_OK_CHGIN_MASK) ? 1 : 0;

	return 0;
}

static enum power_supply_property max77693_charger_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_MODEL_NAME,
	POWER_SUPPLY_PROP_MANUFACTURER,
};

static int max77693_charger_get_property(struct power_supply *psy,
			    enum power_supply_property psp,
			    union power_supply_propval *val)
{
	struct max77693_charger *chg = power_supply_get_drvdata(psy);
	struct regmap *regmap = chg->max77693->regmap;
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
		ret = max77693_get_charger_state(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
		ret = max77693_get_charge_type(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_HEALTH:
		ret = max77693_get_battery_health(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_PRESENT:
		ret = max77693_get_present(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_ONLINE:
		ret = max77693_get_online(regmap, &val->intval);
		break;
	case POWER_SUPPLY_PROP_MODEL_NAME:
		val->strval = max77693_charger_model;
		break;
	case POWER_SUPPLY_PROP_MANUFACTURER:
		val->strval = max77693_charger_manufacturer;
		break;
	default:
		return -EINVAL;
	}

	return ret;
}

static const struct power_supply_desc max77693_charger_desc = {
	.name		= MAX77693_CHARGER_NAME,
	.type		= POWER_SUPPLY_TYPE_BATTERY,
	.properties	= max77693_charger_props,
	.num_properties	= ARRAY_SIZE(max77693_charger_props),
	.get_property	= max77693_charger_get_property,
};

static ssize_t device_attr_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count,
		int (*fn)(struct max77693_charger *, unsigned long))
{
	struct max77693_charger *chg = dev_get_drvdata(dev);
	unsigned long val;
	int ret;

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

	ret = fn(chg, val);
	if (ret)
		return ret;

	return count;
}

static ssize_t fast_charge_timer_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct max77693_charger *chg = dev_get_drvdata(dev);
	unsigned int data, val;
	int ret;

	ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_01,
			&data);
	if (ret < 0)
		return ret;

	data &= CHG_CNFG_01_FCHGTIME_MASK;
	data >>= CHG_CNFG_01_FCHGTIME_SHIFT;
	switch (data) {
	case 0x1 ... 0x7:
		/* Starting from 4 hours, step by 2 hours */
		val = 4 + (data - 1) * 2;
		break;
	case 0x0:
	default:
		val = 0;
		break;
	}

	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
}

static int max77693_set_fast_charge_timer(struct max77693_charger *chg,
		unsigned long hours)
{
	unsigned int data;

	/*
	 * 0x00 - disable
	 * 0x01 - 4h
	 * 0x02 - 6h
	 * ...
	 * 0x07 - 16h
	 * Round down odd values.
	 */
	switch (hours) {
	case 4 ... 16:
		data = (hours - 4) / 2 + 1;
		break;
	case 0:
		/* Disable */
		data = 0;
		break;
	default:
		return -EINVAL;
	}
	data <<= CHG_CNFG_01_FCHGTIME_SHIFT;

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_01,
			CHG_CNFG_01_FCHGTIME_MASK, data);
}

static ssize_t fast_charge_timer_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return device_attr_store(dev, attr, buf, count,
			max77693_set_fast_charge_timer);
}

static ssize_t top_off_threshold_current_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct max77693_charger *chg = dev_get_drvdata(dev);
	unsigned int data, val;
	int ret;

	ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_03,
			&data);
	if (ret < 0)
		return ret;

	data &= CHG_CNFG_03_TOITH_MASK;
	data >>= CHG_CNFG_03_TOITH_SHIFT;

	if (data <= 0x04)
		val = 100000 + data * 25000;
	else
		val = data * 50000;

	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
}

static int max77693_set_top_off_threshold_current(struct max77693_charger *chg,
		unsigned long uamp)
{
	unsigned int data;

	if (uamp < 100000 || uamp > 350000)
		return -EINVAL;

	if (uamp <= 200000)
		data = (uamp - 100000) / 25000;
	else
		/* (200000, 350000> */
		data = uamp / 50000;

	data <<= CHG_CNFG_03_TOITH_SHIFT;

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_03,
			CHG_CNFG_03_TOITH_MASK, data);
}

static ssize_t top_off_threshold_current_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return device_attr_store(dev, attr, buf, count,
			max77693_set_top_off_threshold_current);
}

static ssize_t top_off_timer_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct max77693_charger *chg = dev_get_drvdata(dev);
	unsigned int data, val;
	int ret;

	ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_03,
			&data);
	if (ret < 0)
		return ret;

	data &= CHG_CNFG_03_TOTIME_MASK;
	data >>= CHG_CNFG_03_TOTIME_SHIFT;

	val = data * 10;

	return scnprintf(buf, PAGE_SIZE, "%u\n", val);
}

static int max77693_set_top_off_timer(struct max77693_charger *chg,
		unsigned long minutes)
{
	unsigned int data;

	if (minutes > 70)
		return -EINVAL;

	data = minutes / 10;
	data <<= CHG_CNFG_03_TOTIME_SHIFT;

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_03,
			CHG_CNFG_03_TOTIME_MASK, data);
}

static ssize_t top_off_timer_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return device_attr_store(dev, attr, buf, count,
			max77693_set_top_off_timer);
}

static DEVICE_ATTR_RW(fast_charge_timer);
static DEVICE_ATTR_RW(top_off_threshold_current);
static DEVICE_ATTR_RW(top_off_timer);

static int max77693_set_constant_volt(struct max77693_charger *chg,
		unsigned int uvolt)
{
	unsigned int data;

	/*
	 * 0x00 - 3.650 V
	 * 0x01 - 3.675 V
	 * ...
	 * 0x1b - 4.325 V
	 * 0x1c - 4.340 V
	 * 0x1d - 4.350 V
	 * 0x1e - 4.375 V
	 * 0x1f - 4.400 V
	 */
	if (uvolt >= 3650000 && uvolt < 4340000)
		data = (uvolt - 3650000) / 25000;
	else if (uvolt >= 4340000 && uvolt < 4350000)
		data = 0x1c;
	else if (uvolt >= 4350000 && uvolt <= 4400000)
		data = 0x1d + (uvolt - 4350000) / 25000;
	else {
		dev_err(chg->dev, "Wrong value for charging constant voltage\n");
		return -EINVAL;
	}

	data <<= CHG_CNFG_04_CHGCVPRM_SHIFT;

	dev_dbg(chg->dev, "Charging constant voltage: %u (0x%x)\n", uvolt,
			data);

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_04,
			CHG_CNFG_04_CHGCVPRM_MASK, data);
}

static int max77693_set_min_system_volt(struct max77693_charger *chg,
		unsigned int uvolt)
{
	unsigned int data;

	if (uvolt < 3000000 || uvolt > 3700000) {
		dev_err(chg->dev, "Wrong value for minimum system regulation voltage\n");
		return -EINVAL;
	}

	data = (uvolt - 3000000) / 100000;

	data <<= CHG_CNFG_04_MINVSYS_SHIFT;

	dev_dbg(chg->dev, "Minimum system regulation voltage: %u (0x%x)\n",
			uvolt, data);

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_04,
			CHG_CNFG_04_MINVSYS_MASK, data);
}

static int max77693_set_thermal_regulation_temp(struct max77693_charger *chg,
		unsigned int cels)
{
	unsigned int data;

	switch (cels) {
	case 70:
	case 85:
	case 100:
	case 115:
		data = (cels - 70) / 15;
		break;
	default:
		dev_err(chg->dev, "Wrong value for thermal regulation loop temperature\n");
		return -EINVAL;
	}

	data <<= CHG_CNFG_07_REGTEMP_SHIFT;

	dev_dbg(chg->dev, "Thermal regulation loop temperature: %u (0x%x)\n",
			cels, data);

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_07,
			CHG_CNFG_07_REGTEMP_MASK, data);
}

static int max77693_set_batttery_overcurrent(struct max77693_charger *chg,
		unsigned int uamp)
{
	unsigned int data;

	if (uamp && (uamp < 2000000 || uamp > 3500000)) {
		dev_err(chg->dev, "Wrong value for battery overcurrent\n");
		return -EINVAL;
	}

	if (uamp)
		data = ((uamp - 2000000) / 250000) + 1;
	else
		data = 0; /* disable */

	data <<= CHG_CNFG_12_B2SOVRC_SHIFT;

	dev_dbg(chg->dev, "Battery overcurrent: %u (0x%x)\n", uamp, data);

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_12,
			CHG_CNFG_12_B2SOVRC_MASK, data);
}

static int max77693_set_charge_input_threshold_volt(struct max77693_charger *chg,
		unsigned int uvolt)
{
	unsigned int data;

	switch (uvolt) {
	case 4300000:
		data = 0x0;
		break;
	case 4700000:
	case 4800000:
	case 4900000:
		data = (uvolt - 4700000) / 100000;
	default:
		dev_err(chg->dev, "Wrong value for charge input voltage regulation threshold\n");
		return -EINVAL;
	}

	data <<= CHG_CNFG_12_VCHGINREG_SHIFT;

	dev_dbg(chg->dev, "Charge input voltage regulation threshold: %u (0x%x)\n",
			uvolt, data);

	return regmap_update_bits(chg->max77693->regmap,
			MAX77693_CHG_REG_CHG_CNFG_12,
			CHG_CNFG_12_VCHGINREG_MASK, data);
}

/*
 * Sets charger registers to proper and safe default values.
 */
static int max77693_reg_init(struct max77693_charger *chg)
{
	int ret;
	unsigned int data;

	/* Unlock charger register protection */
	data = (0x3 << CHG_CNFG_06_CHGPROT_SHIFT);
	ret = regmap_update_bits(chg->max77693->regmap,
				MAX77693_CHG_REG_CHG_CNFG_06,
				CHG_CNFG_06_CHGPROT_MASK, data);
	if (ret) {
		dev_err(chg->dev, "Error unlocking registers: %d\n", ret);
		return ret;
	}

	ret = max77693_set_fast_charge_timer(chg, DEFAULT_FAST_CHARGE_TIMER);
	if (ret)
		return ret;

	ret = max77693_set_top_off_threshold_current(chg,
			DEFAULT_TOP_OFF_THRESHOLD_CURRENT);
	if (ret)
		return ret;

	ret = max77693_set_top_off_timer(chg, DEFAULT_TOP_OFF_TIMER);
	if (ret)
		return ret;

	ret = max77693_set_constant_volt(chg, chg->constant_volt);
	if (ret)
		return ret;

	ret = max77693_set_min_system_volt(chg, chg->min_system_volt);
	if (ret)
		return ret;

	ret = max77693_set_thermal_regulation_temp(chg,
			chg->thermal_regulation_temp);
	if (ret)
		return ret;

	ret = max77693_set_batttery_overcurrent(chg, chg->batttery_overcurrent);
	if (ret)
		return ret;

	return max77693_set_charge_input_threshold_volt(chg,
			chg->charge_input_threshold_volt);
}

#ifdef CONFIG_OF
static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
{
	struct device_node *np = dev->of_node;

	if (!np) {
		dev_err(dev, "no charger OF node\n");
		return -EINVAL;
	}

	if (of_property_read_u32(np, "maxim,constant-microvolt",
			&chg->constant_volt))
		chg->constant_volt = DEFAULT_CONSTANT_VOLT;

	if (of_property_read_u32(np, "maxim,min-system-microvolt",
			&chg->min_system_volt))
		chg->min_system_volt = DEFAULT_MIN_SYSTEM_VOLT;

	if (of_property_read_u32(np, "maxim,thermal-regulation-celsius",
			&chg->thermal_regulation_temp))
		chg->thermal_regulation_temp = DEFAULT_THERMAL_REGULATION_TEMP;

	if (of_property_read_u32(np, "maxim,battery-overcurrent-microamp",
			&chg->batttery_overcurrent))
		chg->batttery_overcurrent = DEFAULT_BATTERY_OVERCURRENT;

	if (of_property_read_u32(np, "maxim,charge-input-threshold-microvolt",
			&chg->charge_input_threshold_volt))
		chg->charge_input_threshold_volt =
			DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT;

	return 0;
}
#else /* CONFIG_OF */
static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
{
	return 0;
}
#endif /* CONFIG_OF */

static int max77693_charger_probe(struct platform_device *pdev)
{
	struct max77693_charger *chg;
	struct power_supply_config psy_cfg = {};
	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
	int ret;

	chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
	if (!chg)
		return -ENOMEM;

	platform_set_drvdata(pdev, chg);
	chg->dev = &pdev->dev;
	chg->max77693 = max77693;

	ret = max77693_dt_init(&pdev->dev, chg);
	if (ret)
		return ret;

	ret = max77693_reg_init(chg);
	if (ret)
		return ret;

	psy_cfg.drv_data = chg;

	ret = device_create_file(&pdev->dev, &dev_attr_fast_charge_timer);
	if (ret) {
		dev_err(&pdev->dev, "failed: create fast charge timer sysfs entry\n");
		goto err;
	}

	ret = device_create_file(&pdev->dev,
			&dev_attr_top_off_threshold_current);
	if (ret) {
		dev_err(&pdev->dev, "failed: create top off current sysfs entry\n");
		goto err;
	}

	ret = device_create_file(&pdev->dev, &dev_attr_top_off_timer);
	if (ret) {
		dev_err(&pdev->dev, "failed: create top off timer sysfs entry\n");
		goto err;
	}

	chg->charger = power_supply_register(&pdev->dev,
						&max77693_charger_desc,
						&psy_cfg);
	if (IS_ERR(chg->charger)) {
		dev_err(&pdev->dev, "failed: power supply register\n");
		ret = PTR_ERR(chg->charger);
		goto err;
	}

	return 0;

err:
	device_remove_file(&pdev->dev, &dev_attr_top_off_timer);
	device_remove_file(&pdev->dev, &dev_attr_top_off_threshold_current);
	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);

	return ret;
}

static int max77693_charger_remove(struct platform_device *pdev)
{
	struct max77693_charger *chg = platform_get_drvdata(pdev);

	device_remove_file(&pdev->dev, &dev_attr_top_off_timer);
	device_remove_file(&pdev->dev, &dev_attr_top_off_threshold_current);
	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);

	power_supply_unregister(chg->charger);

	return 0;
}

static const struct platform_device_id max77693_charger_id[] = {
	{ "max77693-charger", 0, },
	{ }
};
MODULE_DEVICE_TABLE(platform, max77693_charger_id);

static struct platform_driver max77693_charger_driver = {
	.driver = {
		.name	= "max77693-charger",
	},
	.probe		= max77693_charger_probe,
	.remove		= max77693_charger_remove,
	.id_table	= max77693_charger_id,
};
module_platform_driver(max77693_charger_driver);

MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
MODULE_DESCRIPTION("Maxim 77693 charger driver");
MODULE_LICENSE("GPL");