1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Driver for Analog Devices (Linear Technology) LTC4162-L charger IC.
4  *  Copyright (C) 2020, Topic Embedded Products
5  */
6 
7 #include <linux/module.h>
8 #include <linux/delay.h>
9 #include <linux/of_device.h>
10 #include <linux/pm_runtime.h>
11 #include <linux/power_supply.h>
12 #include <linux/i2c.h>
13 #include <linux/regmap.h>
14 
15 /* Registers (names based on what datasheet uses) */
16 #define LTC4162L_EN_LIMIT_ALERTS_REG		0x0D
17 #define LTC4162L_EN_CHARGER_STATE_ALERTS_REG	0x0E
18 #define LTC4162L_EN_CHARGE_STATUS_ALERTS_REG	0x0F
19 #define LTC4162L_CONFIG_BITS_REG		0x14
20 #define LTC4162L_IIN_LIMIT_TARGET		0x15
21 #define LTC4162L_ARM_SHIP_MODE			0x19
22 #define LTC4162L_CHARGE_CURRENT_SETTING		0X1A
23 #define LTC4162L_VCHARGE_SETTING		0X1B
24 #define LTC4162L_C_OVER_X_THRESHOLD		0x1C
25 #define LTC4162L_MAX_CV_TIME			0X1D
26 #define LTC4162L_MAX_CHARGE_TIME		0X1E
27 #define LTC4162L_CHARGER_CONFIG_BITS		0x29
28 #define LTC4162L_CHARGER_STATE			0x34
29 #define LTC4162L_CHARGE_STATUS			0x35
30 #define LTC4162L_LIMIT_ALERTS_REG		0x36
31 #define LTC4162L_CHARGER_STATE_ALERTS_REG	0x37
32 #define LTC4162L_CHARGE_STATUS_ALERTS_REG	0x38
33 #define LTC4162L_SYSTEM_STATUS_REG		0x39
34 #define LTC4162L_VBAT				0x3A
35 #define LTC4162L_VIN				0x3B
36 #define LTC4162L_VOUT				0x3C
37 #define LTC4162L_IBAT				0x3D
38 #define LTC4162L_IIN				0x3E
39 #define LTC4162L_DIE_TEMPERATURE		0x3F
40 #define LTC4162L_THERMISTOR_VOLTAGE		0x40
41 #define LTC4162L_BSR				0x41
42 #define LTC4162L_JEITA_REGION			0x42
43 #define LTC4162L_CHEM_CELLS_REG			0x43
44 #define LTC4162L_ICHARGE_DAC			0x44
45 #define LTC4162L_VCHARGE_DAC			0x45
46 #define LTC4162L_IIN_LIMIT_DAC			0x46
47 #define LTC4162L_VBAT_FILT			0x47
48 #define LTC4162L_INPUT_UNDERVOLTAGE_DAC		0x4B
49 
50 /* Enumeration as in datasheet. Individual bits are mutually exclusive. */
51 enum ltc4162l_state {
52 	battery_detection = 2048,
53 	charger_suspended = 256,
54 	precharge = 128,   /* trickle on low bat voltage */
55 	cc_cv_charge = 64, /* normal charge */
56 	ntc_pause = 32,
57 	timer_term = 16,
58 	c_over_x_term = 8, /* battery is full */
59 	max_charge_time_fault = 4,
60 	bat_missing_fault = 2,
61 	bat_short_fault = 1
62 };
63 
64 /* Individual bits are mutually exclusive. Only active in charging states.*/
65 enum ltc4162l_charge_status {
66 	ilim_reg_active = 32,
67 	thermal_reg_active = 16,
68 	vin_uvcl_active = 8,
69 	iin_limit_active = 4,
70 	constant_current = 2,
71 	constant_voltage = 1,
72 	charger_off = 0
73 };
74 
75 /* Magic number to write to ARM_SHIP_MODE register */
76 #define LTC4162L_ARM_SHIP_MODE_MAGIC 21325
77 
78 struct ltc4162l_info {
79 	struct i2c_client	*client;
80 	struct regmap		*regmap;
81 	struct power_supply	*charger;
82 	u32 rsnsb;	/* Series resistor that sets charge current, microOhm */
83 	u32 rsnsi;	/* Series resistor to measure input current, microOhm */
84 	u8 cell_count;	/* Number of connected cells, 0 while unknown */
85 };
86 
87 static u8 ltc4162l_get_cell_count(struct ltc4162l_info *info)
88 {
89 	int ret;
90 	unsigned int val;
91 
92 	/* Once read successfully */
93 	if (info->cell_count)
94 		return info->cell_count;
95 
96 	ret = regmap_read(info->regmap, LTC4162L_CHEM_CELLS_REG, &val);
97 	if (ret)
98 		return 0;
99 
100 	/* Lower 4 bits is the cell count, or 0 if the chip doesn't know yet */
101 	val &= 0x0f;
102 	if (!val)
103 		return 0;
104 
105 	/* Once determined, keep the value */
106 	info->cell_count = val;
107 
108 	return val;
109 };
110 
111 /* Convert enum value to POWER_SUPPLY_STATUS value */
112 static int ltc4162l_state_decode(enum ltc4162l_state value)
113 {
114 	switch (value) {
115 	case precharge:
116 	case cc_cv_charge:
117 		return POWER_SUPPLY_STATUS_CHARGING;
118 	case c_over_x_term:
119 		return POWER_SUPPLY_STATUS_FULL;
120 	case bat_missing_fault:
121 	case bat_short_fault:
122 		return POWER_SUPPLY_STATUS_UNKNOWN;
123 	default:
124 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
125 	}
126 };
127 
128 static int ltc4162l_get_status(struct ltc4162l_info *info,
129 			       union power_supply_propval *val)
130 {
131 	unsigned int regval;
132 	int ret;
133 
134 	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);
135 	if (ret) {
136 		dev_err(&info->client->dev, "Failed to read CHARGER_STATE\n");
137 		return ret;
138 	}
139 
140 	val->intval = ltc4162l_state_decode(regval);
141 
142 	return 0;
143 }
144 
145 static int ltc4162l_charge_status_decode(enum ltc4162l_charge_status value)
146 {
147 	if (!value)
148 		return POWER_SUPPLY_CHARGE_TYPE_NONE;
149 
150 	/* constant voltage/current and input_current limit are "fast" modes */
151 	if (value <= iin_limit_active)
152 		return POWER_SUPPLY_CHARGE_TYPE_FAST;
153 
154 	/* Anything that's not fast we'll return as trickle */
155 	return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
156 }
157 
158 static int ltc4162l_get_charge_type(struct ltc4162l_info *info,
159 				    union power_supply_propval *val)
160 {
161 	unsigned int regval;
162 	int ret;
163 
164 	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);
165 	if (ret)
166 		return ret;
167 
168 	val->intval = ltc4162l_charge_status_decode(regval);
169 
170 	return 0;
171 }
172 
173 static int ltc4162l_state_to_health(enum ltc4162l_state value)
174 {
175 	switch (value) {
176 	case ntc_pause:
177 		return POWER_SUPPLY_HEALTH_OVERHEAT;
178 	case timer_term:
179 		return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
180 	case max_charge_time_fault:
181 		return POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE;
182 	case bat_missing_fault:
183 		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
184 	case bat_short_fault:
185 		return POWER_SUPPLY_HEALTH_DEAD;
186 	default:
187 		return POWER_SUPPLY_HEALTH_GOOD;
188 	}
189 }
190 
191 static int ltc4162l_get_health(struct ltc4162l_info *info,
192 			       union power_supply_propval *val)
193 {
194 	unsigned int regval;
195 	int ret;
196 
197 	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);
198 	if (ret)
199 		return ret;
200 
201 	val->intval = ltc4162l_state_to_health(regval);
202 
203 	return 0;
204 }
205 
206 static int ltc4162l_get_online(struct ltc4162l_info *info,
207 			       union power_supply_propval *val)
208 {
209 	unsigned int regval;
210 	int ret;
211 
212 	ret = regmap_read(info->regmap, LTC4162L_SYSTEM_STATUS_REG, &regval);
213 	if (ret)
214 		return ret;
215 
216 	/* BIT(2) indicates if input voltage is sufficient to charge */
217 	val->intval = !!(regval & BIT(2));
218 
219 	return 0;
220 }
221 
222 static int ltc4162l_get_vbat(struct ltc4162l_info *info,
223 				  unsigned int reg,
224 				  union power_supply_propval *val)
225 {
226 	unsigned int regval;
227 	int ret;
228 
229 	ret = regmap_read(info->regmap, reg, &regval);
230 	if (ret)
231 		return ret;
232 
233 	/* cell_count × 192.4μV/LSB */
234 	regval *= 1924;
235 	regval *= ltc4162l_get_cell_count(info);
236 	regval /= 10;
237 	val->intval = regval;
238 
239 	return 0;
240 }
241 
242 static int ltc4162l_get_ibat(struct ltc4162l_info *info,
243 			     union power_supply_propval *val)
244 {
245 	unsigned int regval;
246 	int ret;
247 
248 	ret = regmap_read(info->regmap, LTC4162L_IBAT, &regval);
249 	if (ret)
250 		return ret;
251 
252 	/* Signed 16-bit number, 1.466μV / RSNSB amperes/LSB. */
253 	ret = (s16)(regval & 0xFFFF);
254 	val->intval = 100 * mult_frac(ret, 14660, (int)info->rsnsb);
255 
256 	return 0;
257 }
258 
259 
260 static int ltc4162l_get_input_voltage(struct ltc4162l_info *info,
261 				      union power_supply_propval *val)
262 {
263 	unsigned int regval;
264 	int ret;
265 
266 	ret = regmap_read(info->regmap, LTC4162L_VIN, &regval);
267 	if (ret)
268 		return ret;
269 
270 	/* 1.649mV/LSB */
271 	val->intval =  regval * 1694;
272 
273 	return 0;
274 }
275 
276 static int ltc4162l_get_input_current(struct ltc4162l_info *info,
277 				      union power_supply_propval *val)
278 {
279 	unsigned int regval;
280 	int ret;
281 
282 	ret = regmap_read(info->regmap, LTC4162L_IIN, &regval);
283 	if (ret)
284 		return ret;
285 
286 	/* Signed 16-bit number, 1.466μV / RSNSI amperes/LSB. */
287 	ret = (s16)(regval & 0xFFFF);
288 	ret *= 14660;
289 	ret /= info->rsnsi;
290 	ret *= 100;
291 
292 	val->intval = ret;
293 
294 	return 0;
295 }
296 
297 static int ltc4162l_get_icharge(struct ltc4162l_info *info,
298 				unsigned int reg,
299 				union power_supply_propval *val)
300 {
301 	unsigned int regval;
302 	int ret;
303 
304 	ret = regmap_read(info->regmap, reg, &regval);
305 	if (ret)
306 		return ret;
307 
308 	regval &= BIT(6) - 1; /* Only the lower 5 bits */
309 
310 	/* The charge current servo level: (icharge_dac + 1) × 1mV/RSNSB */
311 	++regval;
312 	val->intval = 10000u * mult_frac(regval, 100000u, info->rsnsb);
313 
314 	return 0;
315 }
316 
317 static int ltc4162l_set_icharge(struct ltc4162l_info *info,
318 				unsigned int reg,
319 				unsigned int value)
320 {
321 	value = mult_frac(value, info->rsnsb, 100000u);
322 	value /= 10000u;
323 
324 	/* Round to lowest possible */
325 	if (value)
326 		--value;
327 
328 	if (value > 31)
329 		return -EINVAL;
330 
331 	return regmap_write(info->regmap, reg, value);
332 }
333 
334 
335 static int ltc4162l_get_vcharge(struct ltc4162l_info *info,
336 				unsigned int reg,
337 				union power_supply_propval *val)
338 {
339 	unsigned int regval;
340 	int ret;
341 	u32 voltage;
342 
343 	ret = regmap_read(info->regmap, reg, &regval);
344 	if (ret)
345 		return ret;
346 
347 	regval &= BIT(6) - 1; /* Only the lower 5 bits */
348 
349 	/*
350 	 * charge voltage setting can be computed from
351 	 * cell_count × (vcharge_setting × 12.5mV + 3.8125V)
352 	 * where vcharge_setting ranges from 0 to 31 (4.2V max).
353 	 */
354 	voltage = 3812500 + (regval * 12500);
355 	voltage *= ltc4162l_get_cell_count(info);
356 	val->intval = voltage;
357 
358 	return 0;
359 }
360 
361 static int ltc4162l_set_vcharge(struct ltc4162l_info *info,
362 				unsigned int reg,
363 				unsigned int value)
364 {
365 	u8 cell_count = ltc4162l_get_cell_count(info);
366 
367 	if (!cell_count)
368 		return -EBUSY; /* Not available yet, try again later */
369 
370 	value /= cell_count;
371 
372 	if (value < 3812500)
373 		return -EINVAL;
374 
375 	value -= 3812500;
376 	value /= 12500;
377 
378 	if (value > 31)
379 		return -EINVAL;
380 
381 	return regmap_write(info->regmap, reg, value);
382 }
383 
384 static int ltc4162l_get_iin_limit_dac(struct ltc4162l_info *info,
385 				     union power_supply_propval *val)
386 {
387 	unsigned int regval;
388 	int ret;
389 
390 	ret = regmap_read(info->regmap, LTC4162L_IIN_LIMIT_DAC, &regval);
391 	if (ret)
392 		return ret;
393 
394 	regval &= BIT(6) - 1; /* Only 6 bits */
395 
396 	/* (iin_limit_dac + 1) × 500μV / RSNSI */
397 	++regval;
398 	regval *= 5000000u;
399 	regval /= info->rsnsi;
400 	val->intval = 100u * regval;
401 
402 	return 0;
403 }
404 
405 static int ltc4162l_set_iin_limit(struct ltc4162l_info *info,
406 				  unsigned int value)
407 {
408 	unsigned int regval;
409 
410 	regval = mult_frac(value, info->rsnsi, 50000u);
411 	regval /= 10000u;
412 	if (regval)
413 		--regval;
414 	if (regval > 63)
415 		regval = 63;
416 
417 	return regmap_write(info->regmap, LTC4162L_IIN_LIMIT_TARGET, regval);
418 }
419 
420 static int ltc4162l_get_die_temp(struct ltc4162l_info *info,
421 				 union power_supply_propval *val)
422 {
423 	unsigned int regval;
424 	int ret;
425 
426 	ret = regmap_read(info->regmap, LTC4162L_DIE_TEMPERATURE, &regval);
427 	if (ret)
428 		return ret;
429 
430 	/* die_temp × 0.0215°C/LSB - 264.4°C */
431 	ret = (s16)(regval & 0xFFFF);
432 	ret *= 215;
433 	ret /= 100; /* Centidegrees scale */
434 	ret -= 26440;
435 	val->intval = ret;
436 
437 	return 0;
438 }
439 
440 static int ltc4162l_get_term_current(struct ltc4162l_info *info,
441 				     union power_supply_propval *val)
442 {
443 	unsigned int regval;
444 	int ret;
445 
446 	ret = regmap_read(info->regmap, LTC4162L_CHARGER_CONFIG_BITS, &regval);
447 	if (ret)
448 		return ret;
449 
450 	/* Check if C_OVER_X_THRESHOLD is enabled */
451 	if (!(regval & BIT(2))) {
452 		val->intval = 0;
453 		return 0;
454 	}
455 
456 	ret = regmap_read(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, &regval);
457 	if (ret)
458 		return ret;
459 
460 	/* 1.466μV / RSNSB amperes/LSB */
461 	regval *= 14660u;
462 	regval /= info->rsnsb;
463 	val->intval = 100 * regval;
464 
465 	return 0;
466 }
467 
468 static int ltc4162l_set_term_current(struct ltc4162l_info *info,
469 				     unsigned int value)
470 {
471 	int ret;
472 	unsigned int regval;
473 
474 	if (!value) {
475 		/* Disable en_c_over_x_term when set to zero */
476 		return regmap_update_bits(info->regmap,
477 					  LTC4162L_CHARGER_CONFIG_BITS,
478 					  BIT(2), 0);
479 	}
480 
481 	regval = mult_frac(value, info->rsnsb, 14660u);
482 	regval /= 100u;
483 
484 	ret =  regmap_write(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, regval);
485 	if (ret)
486 		return ret;
487 
488 	/* Set en_c_over_x_term after changing the threshold value */
489 	return regmap_update_bits(info->regmap, LTC4162L_CHARGER_CONFIG_BITS,
490 				  BIT(2), BIT(2));
491 }
492 
493 /* Custom properties */
494 static const char * const ltc4162l_charge_status_name[] = {
495 	"ilim_reg_active", /* 32 */
496 	"thermal_reg_active",
497 	"vin_uvcl_active",
498 	"iin_limit_active",
499 	"constant_current",
500 	"constant_voltage",
501 	"charger_off" /* 0 */
502 };
503 
504 static ssize_t charge_status_show(struct device *dev,
505 				  struct device_attribute *attr, char *buf)
506 {
507 	struct power_supply *psy = to_power_supply(dev);
508 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
509 	const char *result = ltc4162l_charge_status_name[
510 				ARRAY_SIZE(ltc4162l_charge_status_name) - 1];
511 	unsigned int regval;
512 	unsigned int mask;
513 	unsigned int index;
514 	int ret;
515 
516 	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);
517 	if (ret)
518 		return ret;
519 
520 	/* Only one bit is set according to datasheet, let's be safe here */
521 	for (mask = 32, index = 0; mask != 0; mask >>= 1, ++index) {
522 		if (regval & mask) {
523 			result = ltc4162l_charge_status_name[index];
524 			break;
525 		}
526 	}
527 
528 	return sprintf(buf, "%s\n", result);
529 }
530 static DEVICE_ATTR_RO(charge_status);
531 
532 static ssize_t vbat_show(struct device *dev,
533 				  struct device_attribute *attr, char *buf)
534 {
535 	struct power_supply *psy = to_power_supply(dev);
536 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
537 	union power_supply_propval val;
538 	int ret;
539 
540 	ret = ltc4162l_get_vbat(info, LTC4162L_VBAT, &val);
541 	if (ret)
542 		return ret;
543 
544 	return sprintf(buf, "%d\n", val.intval);
545 }
546 static DEVICE_ATTR_RO(vbat);
547 
548 static ssize_t vbat_avg_show(struct device *dev,
549 				  struct device_attribute *attr, char *buf)
550 {
551 	struct power_supply *psy = to_power_supply(dev);
552 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
553 	union power_supply_propval val;
554 	int ret;
555 
556 	ret = ltc4162l_get_vbat(info, LTC4162L_VBAT_FILT, &val);
557 	if (ret)
558 		return ret;
559 
560 	return sprintf(buf, "%d\n", val.intval);
561 }
562 static DEVICE_ATTR_RO(vbat_avg);
563 
564 static ssize_t ibat_show(struct device *dev,
565 				  struct device_attribute *attr, char *buf)
566 {
567 	struct power_supply *psy = to_power_supply(dev);
568 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
569 	union power_supply_propval val;
570 	int ret;
571 
572 	ret = ltc4162l_get_ibat(info, &val);
573 	if (ret)
574 		return ret;
575 
576 	return sprintf(buf, "%d\n", val.intval);
577 }
578 static DEVICE_ATTR_RO(ibat);
579 
580 static ssize_t force_telemetry_show(struct device *dev,
581 				    struct device_attribute *attr, char *buf)
582 {
583 	struct power_supply *psy = to_power_supply(dev);
584 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
585 	unsigned int regval;
586 	int ret;
587 
588 	ret = regmap_read(info->regmap, LTC4162L_CONFIG_BITS_REG, &regval);
589 	if (ret)
590 		return ret;
591 
592 	return sprintf(buf, "%u\n", regval & BIT(2) ? 1 : 0);
593 }
594 
595 static ssize_t force_telemetry_store(struct device *dev,
596 	struct device_attribute *attr,
597 	const char *buf,
598 	size_t count)
599 {
600 	struct power_supply *psy = to_power_supply(dev);
601 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
602 	int ret;
603 	unsigned int value;
604 
605 	ret = kstrtouint(buf, 0, &value);
606 	if (ret < 0)
607 		return ret;
608 
609 	ret = regmap_update_bits(info->regmap, LTC4162L_CONFIG_BITS_REG,
610 				 BIT(2), value ? BIT(2) : 0);
611 	if (ret < 0)
612 		return ret;
613 
614 	return count;
615 }
616 
617 static DEVICE_ATTR_RW(force_telemetry);
618 
619 static ssize_t arm_ship_mode_show(struct device *dev,
620 				    struct device_attribute *attr, char *buf)
621 {
622 	struct power_supply *psy = to_power_supply(dev);
623 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
624 	unsigned int regval;
625 	int ret;
626 
627 	ret = regmap_read(info->regmap, LTC4162L_ARM_SHIP_MODE, &regval);
628 	if (ret)
629 		return ret;
630 
631 	return sprintf(buf, "%u\n",
632 		regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);
633 }
634 
635 static ssize_t arm_ship_mode_store(struct device *dev,
636 	struct device_attribute *attr,
637 	const char *buf,
638 	size_t count)
639 {
640 	struct power_supply *psy = to_power_supply(dev);
641 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
642 	int ret;
643 	unsigned int value;
644 
645 	ret = kstrtouint(buf, 0, &value);
646 	if (ret < 0)
647 		return ret;
648 
649 	ret = regmap_write(info->regmap, LTC4162L_ARM_SHIP_MODE,
650 				value ? LTC4162L_ARM_SHIP_MODE_MAGIC : 0);
651 	if (ret < 0)
652 		return ret;
653 
654 	return count;
655 }
656 
657 static DEVICE_ATTR_RW(arm_ship_mode);
658 
659 static struct attribute *ltc4162l_sysfs_entries[] = {
660 	&dev_attr_charge_status.attr,
661 	&dev_attr_ibat.attr,
662 	&dev_attr_vbat.attr,
663 	&dev_attr_vbat_avg.attr,
664 	&dev_attr_force_telemetry.attr,
665 	&dev_attr_arm_ship_mode.attr,
666 	NULL,
667 };
668 
669 static const struct attribute_group ltc4162l_attr_group = {
670 	.name	= NULL,	/* put in device directory */
671 	.attrs	= ltc4162l_sysfs_entries,
672 };
673 
674 static const struct attribute_group *ltc4162l_attr_groups[] = {
675 	&ltc4162l_attr_group,
676 	NULL,
677 };
678 
679 static int ltc4162l_get_property(struct power_supply *psy,
680 				 enum power_supply_property psp,
681 				 union power_supply_propval *val)
682 {
683 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
684 
685 	switch (psp) {
686 	case POWER_SUPPLY_PROP_STATUS:
687 		return ltc4162l_get_status(info, val);
688 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
689 		return ltc4162l_get_charge_type(info, val);
690 	case POWER_SUPPLY_PROP_HEALTH:
691 		return ltc4162l_get_health(info, val);
692 	case POWER_SUPPLY_PROP_ONLINE:
693 		return ltc4162l_get_online(info, val);
694 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
695 		return ltc4162l_get_input_voltage(info, val);
696 	case POWER_SUPPLY_PROP_CURRENT_NOW:
697 		return ltc4162l_get_input_current(info, val);
698 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
699 		return ltc4162l_get_icharge(info,
700 				LTC4162L_ICHARGE_DAC, val);
701 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
702 		return ltc4162l_get_icharge(info,
703 				LTC4162L_CHARGE_CURRENT_SETTING, val);
704 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
705 		return ltc4162l_get_vcharge(info,
706 				LTC4162L_VCHARGE_DAC, val);
707 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
708 		return ltc4162l_get_vcharge(info,
709 				LTC4162L_VCHARGE_SETTING, val);
710 	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
711 		return ltc4162l_get_iin_limit_dac(info, val);
712 	case POWER_SUPPLY_PROP_TEMP:
713 		return ltc4162l_get_die_temp(info, val);
714 	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
715 		return ltc4162l_get_term_current(info, val);
716 	default:
717 		return -EINVAL;
718 	}
719 }
720 
721 static int ltc4162l_set_property(struct power_supply *psy,
722 					 enum power_supply_property psp,
723 					 const union power_supply_propval *val)
724 {
725 	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
726 
727 	switch (psp) {
728 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
729 		return ltc4162l_set_icharge(info,
730 				LTC4162L_CHARGE_CURRENT_SETTING, val->intval);
731 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
732 		return ltc4162l_set_vcharge(info,
733 				LTC4162L_VCHARGE_SETTING, val->intval);
734 	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
735 		return ltc4162l_set_iin_limit(info, val->intval);
736 	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
737 		return ltc4162l_set_term_current(info, val->intval);
738 	default:
739 		return -EINVAL;
740 	}
741 }
742 
743 static int ltc4162l_property_is_writeable(struct power_supply *psy,
744 						enum power_supply_property psp)
745 {
746 	switch (psp) {
747 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
748 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
749 	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
750 	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
751 		return 1;
752 	default:
753 		return 0;
754 	}
755 }
756 
757 /* Charger power supply property routines */
758 static enum power_supply_property ltc4162l_properties[] = {
759 	POWER_SUPPLY_PROP_STATUS,
760 	POWER_SUPPLY_PROP_CHARGE_TYPE,
761 	POWER_SUPPLY_PROP_HEALTH,
762 	POWER_SUPPLY_PROP_ONLINE,
763 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
764 	POWER_SUPPLY_PROP_CURRENT_NOW,
765 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
766 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
767 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
768 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
769 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
770 	POWER_SUPPLY_PROP_TEMP,
771 	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
772 };
773 
774 static const struct power_supply_desc ltc4162l_desc = {
775 	.name		= "ltc4162-l",
776 	.type		= POWER_SUPPLY_TYPE_MAINS,
777 	.properties	= ltc4162l_properties,
778 	.num_properties	= ARRAY_SIZE(ltc4162l_properties),
779 	.get_property	= ltc4162l_get_property,
780 	.set_property	= ltc4162l_set_property,
781 	.property_is_writeable = ltc4162l_property_is_writeable,
782 };
783 
784 static bool ltc4162l_is_writeable_reg(struct device *dev, unsigned int reg)
785 {
786 	/* all registers up to this one are writeable */
787 	if (reg <= LTC4162L_CHARGER_CONFIG_BITS)
788 		return true;
789 
790 	/* The ALERTS registers can be written to clear alerts */
791 	if (reg >= LTC4162L_LIMIT_ALERTS_REG &&
792 	    reg <= LTC4162L_CHARGE_STATUS_ALERTS_REG)
793 		return true;
794 
795 	return false;
796 }
797 
798 static bool ltc4162l_is_volatile_reg(struct device *dev, unsigned int reg)
799 {
800 	/* all registers after this one are read-only status registers */
801 	return reg > LTC4162L_CHARGER_CONFIG_BITS;
802 }
803 
804 static const struct regmap_config ltc4162l_regmap_config = {
805 	.reg_bits	= 8,
806 	.val_bits	= 16,
807 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
808 	.writeable_reg	= ltc4162l_is_writeable_reg,
809 	.volatile_reg	= ltc4162l_is_volatile_reg,
810 	.max_register	= LTC4162L_INPUT_UNDERVOLTAGE_DAC,
811 	.cache_type	= REGCACHE_RBTREE,
812 };
813 
814 static void ltc4162l_clear_interrupts(struct ltc4162l_info *info)
815 {
816 	/* Acknowledge interrupt to chip by clearing all events */
817 	regmap_write(info->regmap, LTC4162L_LIMIT_ALERTS_REG, 0);
818 	regmap_write(info->regmap, LTC4162L_CHARGER_STATE_ALERTS_REG, 0);
819 	regmap_write(info->regmap, LTC4162L_CHARGE_STATUS_ALERTS_REG, 0);
820 }
821 
822 static int ltc4162l_probe(struct i2c_client *client,
823 			const struct i2c_device_id *id)
824 {
825 	struct i2c_adapter *adapter = client->adapter;
826 	struct device *dev = &client->dev;
827 	struct ltc4162l_info *info;
828 	struct power_supply_config ltc4162l_config = {};
829 	u32 value;
830 	int ret;
831 
832 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
833 		dev_err(dev, "No support for SMBUS_WORD_DATA\n");
834 		return -ENODEV;
835 	}
836 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
837 	if (!info)
838 		return -ENOMEM;
839 
840 	info->client = client;
841 	i2c_set_clientdata(client, info);
842 
843 	info->regmap = devm_regmap_init_i2c(client, &ltc4162l_regmap_config);
844 	if (IS_ERR(info->regmap)) {
845 		dev_err(dev, "Failed to initialize register map\n");
846 		return PTR_ERR(info->regmap);
847 	}
848 
849 	ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",
850 				       &info->rsnsb);
851 	if (ret) {
852 		dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");
853 		return ret;
854 	}
855 	if (!info->rsnsb)
856 		return -EINVAL;
857 
858 	ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",
859 				       &info->rsnsi);
860 	if (ret) {
861 		dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");
862 		return ret;
863 	}
864 	if (!info->rsnsi)
865 		return -EINVAL;
866 
867 	if (!device_property_read_u32(dev, "lltc,cell-count", &value))
868 		info->cell_count = value;
869 
870 	ltc4162l_config.of_node = dev->of_node;
871 	ltc4162l_config.drv_data = info;
872 	ltc4162l_config.attr_grp = ltc4162l_attr_groups;
873 
874 	info->charger = devm_power_supply_register(dev, &ltc4162l_desc,
875 						   &ltc4162l_config);
876 	if (IS_ERR(info->charger)) {
877 		dev_err(dev, "Failed to register charger\n");
878 		return PTR_ERR(info->charger);
879 	}
880 
881 	/* Disable the threshold alerts, we're not using them */
882 	regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);
883 
884 	/* Enable interrupts on all status changes */
885 	regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,
886 		     0x1fff);
887 	regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);
888 
889 	ltc4162l_clear_interrupts(info);
890 
891 	return 0;
892 }
893 
894 static void ltc4162l_alert(struct i2c_client *client,
895 			   enum i2c_alert_protocol type, unsigned int flag)
896 {
897 	struct ltc4162l_info *info = i2c_get_clientdata(client);
898 
899 	if (type != I2C_PROTOCOL_SMBUS_ALERT)
900 		return;
901 
902 	ltc4162l_clear_interrupts(info);
903 	power_supply_changed(info->charger);
904 }
905 
906 static const struct i2c_device_id ltc4162l_i2c_id_table[] = {
907 	{ "ltc4162-l", 0 },
908 	{ },
909 };
910 MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);
911 
912 static const struct of_device_id ltc4162l_of_match[] = {
913 	{ .compatible = "lltc,ltc4162-l", },
914 	{ },
915 };
916 MODULE_DEVICE_TABLE(of, ltc4162l_of_match);
917 
918 static struct i2c_driver ltc4162l_driver = {
919 	.probe		= ltc4162l_probe,
920 	.alert		= ltc4162l_alert,
921 	.id_table	= ltc4162l_i2c_id_table,
922 	.driver = {
923 		.name		= "ltc4162-l-charger",
924 		.of_match_table	= of_match_ptr(ltc4162l_of_match),
925 	},
926 };
927 module_i2c_driver(ltc4162l_driver);
928 
929 MODULE_LICENSE("GPL");
930 MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
931 MODULE_DESCRIPTION("LTC4162-L charger driver");
932