xref: /linux/drivers/power/supply/max77693_charger.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // max77693_charger.c - Battery charger driver for the Maxim 77693
4 //
5 // Copyright (C) 2014 Samsung Electronics
6 // Krzysztof Kozlowski <krzk@kernel.org>
7 
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/power_supply.h>
11 #include <linux/regmap.h>
12 #include <linux/mfd/max77693.h>
13 #include <linux/mfd/max77693-common.h>
14 #include <linux/mfd/max77693-private.h>
15 
16 #define MAX77693_CHARGER_NAME				"max77693-charger"
17 static const char *max77693_charger_model		= "MAX77693";
18 static const char *max77693_charger_manufacturer	= "Maxim Integrated";
19 
20 struct max77693_charger {
21 	struct device		*dev;
22 	struct max77693_dev	*max77693;
23 	struct power_supply	*charger;
24 
25 	u32 constant_volt;
26 	u32 min_system_volt;
27 	u32 thermal_regulation_temp;
28 	u32 batttery_overcurrent;
29 	u32 charge_input_threshold_volt;
30 };
31 
32 static int max77693_get_charger_state(struct regmap *regmap, int *val)
33 {
34 	int ret;
35 	unsigned int data;
36 
37 	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data);
38 	if (ret < 0)
39 		return ret;
40 
41 	data &= CHG_DETAILS_01_CHG_MASK;
42 	data >>= CHG_DETAILS_01_CHG_SHIFT;
43 
44 	switch (data) {
45 	case MAX77693_CHARGING_PREQUALIFICATION:
46 	case MAX77693_CHARGING_FAST_CONST_CURRENT:
47 	case MAX77693_CHARGING_FAST_CONST_VOLTAGE:
48 	case MAX77693_CHARGING_TOP_OFF:
49 	/* In high temp the charging current is reduced, but still charging */
50 	case MAX77693_CHARGING_HIGH_TEMP:
51 		*val = POWER_SUPPLY_STATUS_CHARGING;
52 		break;
53 	case MAX77693_CHARGING_DONE:
54 		*val = POWER_SUPPLY_STATUS_FULL;
55 		break;
56 	case MAX77693_CHARGING_TIMER_EXPIRED:
57 	case MAX77693_CHARGING_THERMISTOR_SUSPEND:
58 		*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
59 		break;
60 	case MAX77693_CHARGING_OFF:
61 	case MAX77693_CHARGING_OVER_TEMP:
62 	case MAX77693_CHARGING_WATCHDOG_EXPIRED:
63 		*val = POWER_SUPPLY_STATUS_DISCHARGING;
64 		break;
65 	case MAX77693_CHARGING_RESERVED:
66 	default:
67 		*val = POWER_SUPPLY_STATUS_UNKNOWN;
68 	}
69 
70 	return 0;
71 }
72 
73 static int max77693_get_charge_type(struct regmap *regmap, int *val)
74 {
75 	int ret;
76 	unsigned int data;
77 
78 	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data);
79 	if (ret < 0)
80 		return ret;
81 
82 	data &= CHG_DETAILS_01_CHG_MASK;
83 	data >>= CHG_DETAILS_01_CHG_SHIFT;
84 
85 	switch (data) {
86 	case MAX77693_CHARGING_PREQUALIFICATION:
87 	/*
88 	 * Top-off: trickle or fast? In top-off the current varies between
89 	 * 100 and 250 mA. It is higher than prequalification current.
90 	 */
91 	case MAX77693_CHARGING_TOP_OFF:
92 		*val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
93 		break;
94 	case MAX77693_CHARGING_FAST_CONST_CURRENT:
95 	case MAX77693_CHARGING_FAST_CONST_VOLTAGE:
96 	/* In high temp the charging current is reduced, but still charging */
97 	case MAX77693_CHARGING_HIGH_TEMP:
98 		*val = POWER_SUPPLY_CHARGE_TYPE_FAST;
99 		break;
100 	case MAX77693_CHARGING_DONE:
101 	case MAX77693_CHARGING_TIMER_EXPIRED:
102 	case MAX77693_CHARGING_THERMISTOR_SUSPEND:
103 	case MAX77693_CHARGING_OFF:
104 	case MAX77693_CHARGING_OVER_TEMP:
105 	case MAX77693_CHARGING_WATCHDOG_EXPIRED:
106 		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
107 		break;
108 	case MAX77693_CHARGING_RESERVED:
109 	default:
110 		*val = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
111 	}
112 
113 	return 0;
114 }
115 
116 /*
117  * Supported health statuses:
118  *  - POWER_SUPPLY_HEALTH_DEAD
119  *  - POWER_SUPPLY_HEALTH_GOOD
120  *  - POWER_SUPPLY_HEALTH_OVERVOLTAGE
121  *  - POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE
122  *  - POWER_SUPPLY_HEALTH_UNKNOWN
123  *  - POWER_SUPPLY_HEALTH_UNSPEC_FAILURE
124  */
125 static int max77693_get_battery_health(struct regmap *regmap, int *val)
126 {
127 	int ret;
128 	unsigned int data;
129 
130 	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data);
131 	if (ret < 0)
132 		return ret;
133 
134 	data &= CHG_DETAILS_01_BAT_MASK;
135 	data >>= CHG_DETAILS_01_BAT_SHIFT;
136 
137 	switch (data) {
138 	case MAX77693_BATTERY_NOBAT:
139 		*val = POWER_SUPPLY_HEALTH_DEAD;
140 		break;
141 	case MAX77693_BATTERY_PREQUALIFICATION:
142 	case MAX77693_BATTERY_GOOD:
143 	case MAX77693_BATTERY_LOWVOLTAGE:
144 		*val = POWER_SUPPLY_HEALTH_GOOD;
145 		break;
146 	case MAX77693_BATTERY_TIMER_EXPIRED:
147 		/*
148 		 * Took longer to charge than expected, charging suspended.
149 		 * Damaged battery?
150 		 */
151 		*val = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
152 		break;
153 	case MAX77693_BATTERY_OVERVOLTAGE:
154 		*val = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
155 		break;
156 	case MAX77693_BATTERY_OVERCURRENT:
157 		*val = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
158 		break;
159 	case MAX77693_BATTERY_RESERVED:
160 	default:
161 		*val = POWER_SUPPLY_HEALTH_UNKNOWN;
162 		break;
163 	}
164 
165 	return 0;
166 }
167 
168 static int max77693_get_present(struct regmap *regmap, int *val)
169 {
170 	unsigned int data;
171 	int ret;
172 
173 	/*
174 	 * Read CHG_INT_OK register. High DETBAT bit here should be
175 	 * equal to value 0x0 in CHG_DETAILS_01/BAT field.
176 	 */
177 	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_INT_OK, &data);
178 	if (ret < 0)
179 		return ret;
180 
181 	*val = (data & CHG_INT_OK_DETBAT_MASK) ? 0 : 1;
182 
183 	return 0;
184 }
185 
186 static int max77693_get_online(struct regmap *regmap, int *val)
187 {
188 	unsigned int data;
189 	int ret;
190 
191 	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_INT_OK, &data);
192 	if (ret < 0)
193 		return ret;
194 
195 	*val = (data & CHG_INT_OK_CHGIN_MASK) ? 1 : 0;
196 
197 	return 0;
198 }
199 
200 static enum power_supply_property max77693_charger_props[] = {
201 	POWER_SUPPLY_PROP_STATUS,
202 	POWER_SUPPLY_PROP_CHARGE_TYPE,
203 	POWER_SUPPLY_PROP_HEALTH,
204 	POWER_SUPPLY_PROP_PRESENT,
205 	POWER_SUPPLY_PROP_ONLINE,
206 	POWER_SUPPLY_PROP_MODEL_NAME,
207 	POWER_SUPPLY_PROP_MANUFACTURER,
208 };
209 
210 static int max77693_charger_get_property(struct power_supply *psy,
211 			    enum power_supply_property psp,
212 			    union power_supply_propval *val)
213 {
214 	struct max77693_charger *chg = power_supply_get_drvdata(psy);
215 	struct regmap *regmap = chg->max77693->regmap;
216 	int ret = 0;
217 
218 	switch (psp) {
219 	case POWER_SUPPLY_PROP_STATUS:
220 		ret = max77693_get_charger_state(regmap, &val->intval);
221 		break;
222 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
223 		ret = max77693_get_charge_type(regmap, &val->intval);
224 		break;
225 	case POWER_SUPPLY_PROP_HEALTH:
226 		ret = max77693_get_battery_health(regmap, &val->intval);
227 		break;
228 	case POWER_SUPPLY_PROP_PRESENT:
229 		ret = max77693_get_present(regmap, &val->intval);
230 		break;
231 	case POWER_SUPPLY_PROP_ONLINE:
232 		ret = max77693_get_online(regmap, &val->intval);
233 		break;
234 	case POWER_SUPPLY_PROP_MODEL_NAME:
235 		val->strval = max77693_charger_model;
236 		break;
237 	case POWER_SUPPLY_PROP_MANUFACTURER:
238 		val->strval = max77693_charger_manufacturer;
239 		break;
240 	default:
241 		return -EINVAL;
242 	}
243 
244 	return ret;
245 }
246 
247 static const struct power_supply_desc max77693_charger_desc = {
248 	.name		= MAX77693_CHARGER_NAME,
249 	.type		= POWER_SUPPLY_TYPE_BATTERY,
250 	.properties	= max77693_charger_props,
251 	.num_properties	= ARRAY_SIZE(max77693_charger_props),
252 	.get_property	= max77693_charger_get_property,
253 };
254 
255 static ssize_t device_attr_store(struct device *dev,
256 		struct device_attribute *attr, const char *buf, size_t count,
257 		int (*fn)(struct max77693_charger *, unsigned long))
258 {
259 	struct max77693_charger *chg = dev_get_drvdata(dev);
260 	unsigned long val;
261 	int ret;
262 
263 	ret = kstrtoul(buf, 10, &val);
264 	if (ret)
265 		return ret;
266 
267 	ret = fn(chg, val);
268 	if (ret)
269 		return ret;
270 
271 	return count;
272 }
273 
274 static ssize_t fast_charge_timer_show(struct device *dev,
275 		struct device_attribute *attr, char *buf)
276 {
277 	struct max77693_charger *chg = dev_get_drvdata(dev);
278 	unsigned int data, val;
279 	int ret;
280 
281 	ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_01,
282 			&data);
283 	if (ret < 0)
284 		return ret;
285 
286 	data &= CHG_CNFG_01_FCHGTIME_MASK;
287 	data >>= CHG_CNFG_01_FCHGTIME_SHIFT;
288 	switch (data) {
289 	case 0x1 ... 0x7:
290 		/* Starting from 4 hours, step by 2 hours */
291 		val = 4 + (data - 1) * 2;
292 		break;
293 	case 0x0:
294 	default:
295 		val = 0;
296 		break;
297 	}
298 
299 	return sysfs_emit(buf, "%u\n", val);
300 }
301 
302 static int max77693_set_fast_charge_timer(struct max77693_charger *chg,
303 		unsigned long hours)
304 {
305 	unsigned int data;
306 
307 	/*
308 	 * 0x00 - disable
309 	 * 0x01 - 4h
310 	 * 0x02 - 6h
311 	 * ...
312 	 * 0x07 - 16h
313 	 * Round down odd values.
314 	 */
315 	switch (hours) {
316 	case 4 ... 16:
317 		data = (hours - 4) / 2 + 1;
318 		break;
319 	case 0:
320 		/* Disable */
321 		data = 0;
322 		break;
323 	default:
324 		return -EINVAL;
325 	}
326 	data <<= CHG_CNFG_01_FCHGTIME_SHIFT;
327 
328 	return regmap_update_bits(chg->max77693->regmap,
329 			MAX77693_CHG_REG_CHG_CNFG_01,
330 			CHG_CNFG_01_FCHGTIME_MASK, data);
331 }
332 
333 static ssize_t fast_charge_timer_store(struct device *dev,
334 		struct device_attribute *attr, const char *buf, size_t count)
335 {
336 	return device_attr_store(dev, attr, buf, count,
337 			max77693_set_fast_charge_timer);
338 }
339 
340 static ssize_t top_off_threshold_current_show(struct device *dev,
341 		struct device_attribute *attr, char *buf)
342 {
343 	struct max77693_charger *chg = dev_get_drvdata(dev);
344 	unsigned int data, val;
345 	int ret;
346 
347 	ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_03,
348 			&data);
349 	if (ret < 0)
350 		return ret;
351 
352 	data &= CHG_CNFG_03_TOITH_MASK;
353 	data >>= CHG_CNFG_03_TOITH_SHIFT;
354 
355 	if (data <= 0x04)
356 		val = 100000 + data * 25000;
357 	else
358 		val = data * 50000;
359 
360 	return sysfs_emit(buf, "%u\n", val);
361 }
362 
363 static int max77693_set_top_off_threshold_current(struct max77693_charger *chg,
364 		unsigned long uamp)
365 {
366 	unsigned int data;
367 
368 	if (uamp < 100000 || uamp > 350000)
369 		return -EINVAL;
370 
371 	if (uamp <= 200000)
372 		data = (uamp - 100000) / 25000;
373 	else
374 		/* (200000, 350000> */
375 		data = uamp / 50000;
376 
377 	data <<= CHG_CNFG_03_TOITH_SHIFT;
378 
379 	return regmap_update_bits(chg->max77693->regmap,
380 			MAX77693_CHG_REG_CHG_CNFG_03,
381 			CHG_CNFG_03_TOITH_MASK, data);
382 }
383 
384 static ssize_t top_off_threshold_current_store(struct device *dev,
385 		struct device_attribute *attr, const char *buf, size_t count)
386 {
387 	return device_attr_store(dev, attr, buf, count,
388 			max77693_set_top_off_threshold_current);
389 }
390 
391 static ssize_t top_off_timer_show(struct device *dev,
392 		struct device_attribute *attr, char *buf)
393 {
394 	struct max77693_charger *chg = dev_get_drvdata(dev);
395 	unsigned int data, val;
396 	int ret;
397 
398 	ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_03,
399 			&data);
400 	if (ret < 0)
401 		return ret;
402 
403 	data &= CHG_CNFG_03_TOTIME_MASK;
404 	data >>= CHG_CNFG_03_TOTIME_SHIFT;
405 
406 	val = data * 10;
407 
408 	return sysfs_emit(buf, "%u\n", val);
409 }
410 
411 static int max77693_set_top_off_timer(struct max77693_charger *chg,
412 		unsigned long minutes)
413 {
414 	unsigned int data;
415 
416 	if (minutes > 70)
417 		return -EINVAL;
418 
419 	data = minutes / 10;
420 	data <<= CHG_CNFG_03_TOTIME_SHIFT;
421 
422 	return regmap_update_bits(chg->max77693->regmap,
423 			MAX77693_CHG_REG_CHG_CNFG_03,
424 			CHG_CNFG_03_TOTIME_MASK, data);
425 }
426 
427 static ssize_t top_off_timer_store(struct device *dev,
428 		struct device_attribute *attr, const char *buf, size_t count)
429 {
430 	return device_attr_store(dev, attr, buf, count,
431 			max77693_set_top_off_timer);
432 }
433 
434 static DEVICE_ATTR_RW(fast_charge_timer);
435 static DEVICE_ATTR_RW(top_off_threshold_current);
436 static DEVICE_ATTR_RW(top_off_timer);
437 
438 static int max77693_set_constant_volt(struct max77693_charger *chg,
439 		unsigned int uvolt)
440 {
441 	unsigned int data;
442 
443 	/*
444 	 * 0x00 - 3.650 V
445 	 * 0x01 - 3.675 V
446 	 * ...
447 	 * 0x1b - 4.325 V
448 	 * 0x1c - 4.340 V
449 	 * 0x1d - 4.350 V
450 	 * 0x1e - 4.375 V
451 	 * 0x1f - 4.400 V
452 	 */
453 	if (uvolt >= 3650000 && uvolt < 4340000)
454 		data = (uvolt - 3650000) / 25000;
455 	else if (uvolt >= 4340000 && uvolt < 4350000)
456 		data = 0x1c;
457 	else if (uvolt >= 4350000 && uvolt <= 4400000)
458 		data = 0x1d + (uvolt - 4350000) / 25000;
459 	else {
460 		dev_err(chg->dev, "Wrong value for charging constant voltage\n");
461 		return -EINVAL;
462 	}
463 
464 	data <<= CHG_CNFG_04_CHGCVPRM_SHIFT;
465 
466 	dev_dbg(chg->dev, "Charging constant voltage: %u (0x%x)\n", uvolt,
467 			data);
468 
469 	return regmap_update_bits(chg->max77693->regmap,
470 			MAX77693_CHG_REG_CHG_CNFG_04,
471 			CHG_CNFG_04_CHGCVPRM_MASK, data);
472 }
473 
474 static int max77693_set_min_system_volt(struct max77693_charger *chg,
475 		unsigned int uvolt)
476 {
477 	unsigned int data;
478 
479 	if (uvolt < 3000000 || uvolt > 3700000) {
480 		dev_err(chg->dev, "Wrong value for minimum system regulation voltage\n");
481 		return -EINVAL;
482 	}
483 
484 	data = (uvolt - 3000000) / 100000;
485 
486 	data <<= CHG_CNFG_04_MINVSYS_SHIFT;
487 
488 	dev_dbg(chg->dev, "Minimum system regulation voltage: %u (0x%x)\n",
489 			uvolt, data);
490 
491 	return regmap_update_bits(chg->max77693->regmap,
492 			MAX77693_CHG_REG_CHG_CNFG_04,
493 			CHG_CNFG_04_MINVSYS_MASK, data);
494 }
495 
496 static int max77693_set_thermal_regulation_temp(struct max77693_charger *chg,
497 		unsigned int cels)
498 {
499 	unsigned int data;
500 
501 	switch (cels) {
502 	case 70:
503 	case 85:
504 	case 100:
505 	case 115:
506 		data = (cels - 70) / 15;
507 		break;
508 	default:
509 		dev_err(chg->dev, "Wrong value for thermal regulation loop temperature\n");
510 		return -EINVAL;
511 	}
512 
513 	data <<= CHG_CNFG_07_REGTEMP_SHIFT;
514 
515 	dev_dbg(chg->dev, "Thermal regulation loop temperature: %u (0x%x)\n",
516 			cels, data);
517 
518 	return regmap_update_bits(chg->max77693->regmap,
519 			MAX77693_CHG_REG_CHG_CNFG_07,
520 			CHG_CNFG_07_REGTEMP_MASK, data);
521 }
522 
523 static int max77693_set_batttery_overcurrent(struct max77693_charger *chg,
524 		unsigned int uamp)
525 {
526 	unsigned int data;
527 
528 	if (uamp && (uamp < 2000000 || uamp > 3500000)) {
529 		dev_err(chg->dev, "Wrong value for battery overcurrent\n");
530 		return -EINVAL;
531 	}
532 
533 	if (uamp)
534 		data = ((uamp - 2000000) / 250000) + 1;
535 	else
536 		data = 0; /* disable */
537 
538 	data <<= CHG_CNFG_12_B2SOVRC_SHIFT;
539 
540 	dev_dbg(chg->dev, "Battery overcurrent: %u (0x%x)\n", uamp, data);
541 
542 	return regmap_update_bits(chg->max77693->regmap,
543 			MAX77693_CHG_REG_CHG_CNFG_12,
544 			CHG_CNFG_12_B2SOVRC_MASK, data);
545 }
546 
547 static int max77693_set_charge_input_threshold_volt(struct max77693_charger *chg,
548 		unsigned int uvolt)
549 {
550 	unsigned int data;
551 
552 	switch (uvolt) {
553 	case 4300000:
554 		data = 0x0;
555 		break;
556 	case 4700000:
557 	case 4800000:
558 	case 4900000:
559 		data = (uvolt - 4700000) / 100000;
560 		break;
561 	default:
562 		dev_err(chg->dev, "Wrong value for charge input voltage regulation threshold\n");
563 		return -EINVAL;
564 	}
565 
566 	data <<= CHG_CNFG_12_VCHGINREG_SHIFT;
567 
568 	dev_dbg(chg->dev, "Charge input voltage regulation threshold: %u (0x%x)\n",
569 			uvolt, data);
570 
571 	return regmap_update_bits(chg->max77693->regmap,
572 			MAX77693_CHG_REG_CHG_CNFG_12,
573 			CHG_CNFG_12_VCHGINREG_MASK, data);
574 }
575 
576 /*
577  * Sets charger registers to proper and safe default values.
578  */
579 static int max77693_reg_init(struct max77693_charger *chg)
580 {
581 	int ret;
582 	unsigned int data;
583 
584 	/* Unlock charger register protection */
585 	data = (0x3 << CHG_CNFG_06_CHGPROT_SHIFT);
586 	ret = regmap_update_bits(chg->max77693->regmap,
587 				MAX77693_CHG_REG_CHG_CNFG_06,
588 				CHG_CNFG_06_CHGPROT_MASK, data);
589 	if (ret) {
590 		dev_err(chg->dev, "Error unlocking registers: %d\n", ret);
591 		return ret;
592 	}
593 
594 	ret = max77693_set_fast_charge_timer(chg, DEFAULT_FAST_CHARGE_TIMER);
595 	if (ret)
596 		return ret;
597 
598 	ret = max77693_set_top_off_threshold_current(chg,
599 			DEFAULT_TOP_OFF_THRESHOLD_CURRENT);
600 	if (ret)
601 		return ret;
602 
603 	ret = max77693_set_top_off_timer(chg, DEFAULT_TOP_OFF_TIMER);
604 	if (ret)
605 		return ret;
606 
607 	ret = max77693_set_constant_volt(chg, chg->constant_volt);
608 	if (ret)
609 		return ret;
610 
611 	ret = max77693_set_min_system_volt(chg, chg->min_system_volt);
612 	if (ret)
613 		return ret;
614 
615 	ret = max77693_set_thermal_regulation_temp(chg,
616 			chg->thermal_regulation_temp);
617 	if (ret)
618 		return ret;
619 
620 	ret = max77693_set_batttery_overcurrent(chg, chg->batttery_overcurrent);
621 	if (ret)
622 		return ret;
623 
624 	return max77693_set_charge_input_threshold_volt(chg,
625 			chg->charge_input_threshold_volt);
626 }
627 
628 #ifdef CONFIG_OF
629 static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
630 {
631 	struct device_node *np = dev->of_node;
632 
633 	if (!np) {
634 		dev_err(dev, "no charger OF node\n");
635 		return -EINVAL;
636 	}
637 
638 	if (of_property_read_u32(np, "maxim,constant-microvolt",
639 			&chg->constant_volt))
640 		chg->constant_volt = DEFAULT_CONSTANT_VOLT;
641 
642 	if (of_property_read_u32(np, "maxim,min-system-microvolt",
643 			&chg->min_system_volt))
644 		chg->min_system_volt = DEFAULT_MIN_SYSTEM_VOLT;
645 
646 	if (of_property_read_u32(np, "maxim,thermal-regulation-celsius",
647 			&chg->thermal_regulation_temp))
648 		chg->thermal_regulation_temp = DEFAULT_THERMAL_REGULATION_TEMP;
649 
650 	if (of_property_read_u32(np, "maxim,battery-overcurrent-microamp",
651 			&chg->batttery_overcurrent))
652 		chg->batttery_overcurrent = DEFAULT_BATTERY_OVERCURRENT;
653 
654 	if (of_property_read_u32(np, "maxim,charge-input-threshold-microvolt",
655 			&chg->charge_input_threshold_volt))
656 		chg->charge_input_threshold_volt =
657 			DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT;
658 
659 	return 0;
660 }
661 #else /* CONFIG_OF */
662 static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
663 {
664 	return 0;
665 }
666 #endif /* CONFIG_OF */
667 
668 static int max77693_charger_probe(struct platform_device *pdev)
669 {
670 	struct max77693_charger *chg;
671 	struct power_supply_config psy_cfg = {};
672 	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
673 	int ret;
674 
675 	chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
676 	if (!chg)
677 		return -ENOMEM;
678 
679 	platform_set_drvdata(pdev, chg);
680 	chg->dev = &pdev->dev;
681 	chg->max77693 = max77693;
682 
683 	ret = max77693_dt_init(&pdev->dev, chg);
684 	if (ret)
685 		return ret;
686 
687 	ret = max77693_reg_init(chg);
688 	if (ret)
689 		return ret;
690 
691 	psy_cfg.drv_data = chg;
692 
693 	ret = device_create_file(&pdev->dev, &dev_attr_fast_charge_timer);
694 	if (ret) {
695 		dev_err(&pdev->dev, "failed: create fast charge timer sysfs entry\n");
696 		goto err;
697 	}
698 
699 	ret = device_create_file(&pdev->dev,
700 			&dev_attr_top_off_threshold_current);
701 	if (ret) {
702 		dev_err(&pdev->dev, "failed: create top off current sysfs entry\n");
703 		goto err;
704 	}
705 
706 	ret = device_create_file(&pdev->dev, &dev_attr_top_off_timer);
707 	if (ret) {
708 		dev_err(&pdev->dev, "failed: create top off timer sysfs entry\n");
709 		goto err;
710 	}
711 
712 	chg->charger = devm_power_supply_register(&pdev->dev,
713 						  &max77693_charger_desc,
714 						  &psy_cfg);
715 	if (IS_ERR(chg->charger)) {
716 		dev_err(&pdev->dev, "failed: power supply register\n");
717 		ret = PTR_ERR(chg->charger);
718 		goto err;
719 	}
720 
721 	return 0;
722 
723 err:
724 	device_remove_file(&pdev->dev, &dev_attr_top_off_timer);
725 	device_remove_file(&pdev->dev, &dev_attr_top_off_threshold_current);
726 	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);
727 
728 	return ret;
729 }
730 
731 static void max77693_charger_remove(struct platform_device *pdev)
732 {
733 	device_remove_file(&pdev->dev, &dev_attr_top_off_timer);
734 	device_remove_file(&pdev->dev, &dev_attr_top_off_threshold_current);
735 	device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);
736 }
737 
738 static const struct platform_device_id max77693_charger_id[] = {
739 	{ "max77693-charger", 0, },
740 	{ }
741 };
742 MODULE_DEVICE_TABLE(platform, max77693_charger_id);
743 
744 static struct platform_driver max77693_charger_driver = {
745 	.driver = {
746 		.name	= "max77693-charger",
747 	},
748 	.probe		= max77693_charger_probe,
749 	.remove_new	= max77693_charger_remove,
750 	.id_table	= max77693_charger_id,
751 };
752 module_platform_driver(max77693_charger_driver);
753 
754 MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>");
755 MODULE_DESCRIPTION("Maxim 77693 charger driver");
756 MODULE_LICENSE("GPL");
757