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.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. */
51enum 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.*/
65enum 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
78struct 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
87static 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 */
112static 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
128static 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
145static 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
158static 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
173static 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
191static 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
206static 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
222static 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 �� 192.4��V/LSB */
234	regval *= 1924;
235	regval *= ltc4162l_get_cell_count(info);
236	regval /= 10;
237	val->intval = regval;
238
239	return 0;
240}
241
242static 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, 1.466��V / 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
260static 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
276static 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, 1.466��V / 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
297static 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
317static 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
335static 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
361static 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
384static 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) �� 500��V / RSNSI */
397	++regval;
398	regval *= 5000000u;
399	regval /= info->rsnsi;
400	val->intval = 100u * regval;
401
402	return 0;
403}
404
405static 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
420static 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
440static 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	/* 1.466��V / RSNSB amperes/LSB */
461	regval *= 14660u;
462	regval /= info->rsnsb;
463	val->intval = 100 * regval;
464
465	return 0;
466}
467
468static 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 */
494static 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
504static 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 sysfs_emit(buf, "%s\n", result);
529}
530static DEVICE_ATTR_RO(charge_status);
531
532static 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 sysfs_emit(buf, "%d\n", val.intval);
545}
546static DEVICE_ATTR_RO(vbat);
547
548static 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 sysfs_emit(buf, "%d\n", val.intval);
561}
562static DEVICE_ATTR_RO(vbat_avg);
563
564static 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 sysfs_emit(buf, "%d\n", val.intval);
577}
578static DEVICE_ATTR_RO(ibat);
579
580static 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 sysfs_emit(buf, "%u\n", regval & BIT(2) ? 1 : 0);
593}
594
595static 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
617static DEVICE_ATTR_RW(force_telemetry);
618
619static 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 sysfs_emit(buf, "%u\n",
632		regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);
633}
634
635static 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
657static DEVICE_ATTR_RW(arm_ship_mode);
658
659static 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
669static const struct attribute_group ltc4162l_attr_group = {
670	.name	= NULL,	/* put in device directory */
671	.attrs	= ltc4162l_sysfs_entries,
672};
673
674static const struct attribute_group *ltc4162l_attr_groups[] = {
675	&ltc4162l_attr_group,
676	NULL,
677};
678
679static 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
721static 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
743static 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 */
758static 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
774static 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
784static 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
798static 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
804static 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
814static 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
822static int ltc4162l_probe(struct i2c_client *client)
823{
824	struct i2c_adapter *adapter = client->adapter;
825	struct device *dev = &client->dev;
826	struct ltc4162l_info *info;
827	struct power_supply_config ltc4162l_config = {};
828	u32 value;
829	int ret;
830
831	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
832		dev_err(dev, "No support for SMBUS_WORD_DATA\n");
833		return -ENODEV;
834	}
835	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
836	if (!info)
837		return -ENOMEM;
838
839	info->client = client;
840	i2c_set_clientdata(client, info);
841
842	info->regmap = devm_regmap_init_i2c(client, &ltc4162l_regmap_config);
843	if (IS_ERR(info->regmap)) {
844		dev_err(dev, "Failed to initialize register map\n");
845		return PTR_ERR(info->regmap);
846	}
847
848	ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",
849				       &info->rsnsb);
850	if (ret) {
851		dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");
852		return ret;
853	}
854	if (!info->rsnsb)
855		return -EINVAL;
856
857	ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",
858				       &info->rsnsi);
859	if (ret) {
860		dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");
861		return ret;
862	}
863	if (!info->rsnsi)
864		return -EINVAL;
865
866	if (!device_property_read_u32(dev, "lltc,cell-count", &value))
867		info->cell_count = value;
868
869	ltc4162l_config.of_node = dev->of_node;
870	ltc4162l_config.drv_data = info;
871	ltc4162l_config.attr_grp = ltc4162l_attr_groups;
872
873	info->charger = devm_power_supply_register(dev, &ltc4162l_desc,
874						   &ltc4162l_config);
875	if (IS_ERR(info->charger)) {
876		dev_err(dev, "Failed to register charger\n");
877		return PTR_ERR(info->charger);
878	}
879
880	/* Disable the threshold alerts, we're not using them */
881	regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);
882
883	/* Enable interrupts on all status changes */
884	regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,
885		     0x1fff);
886	regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);
887
888	ltc4162l_clear_interrupts(info);
889
890	return 0;
891}
892
893static void ltc4162l_alert(struct i2c_client *client,
894			   enum i2c_alert_protocol type, unsigned int flag)
895{
896	struct ltc4162l_info *info = i2c_get_clientdata(client);
897
898	if (type != I2C_PROTOCOL_SMBUS_ALERT)
899		return;
900
901	ltc4162l_clear_interrupts(info);
902	power_supply_changed(info->charger);
903}
904
905static const struct i2c_device_id ltc4162l_i2c_id_table[] = {
906	{ "ltc4162-l", 0 },
907	{ },
908};
909MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);
910
911static const struct of_device_id ltc4162l_of_match[] __maybe_unused = {
912	{ .compatible = "lltc,ltc4162-l", },
913	{ },
914};
915MODULE_DEVICE_TABLE(of, ltc4162l_of_match);
916
917static struct i2c_driver ltc4162l_driver = {
918	.probe		= ltc4162l_probe,
919	.alert		= ltc4162l_alert,
920	.id_table	= ltc4162l_i2c_id_table,
921	.driver = {
922		.name		= "ltc4162-l-charger",
923		.of_match_table	= of_match_ptr(ltc4162l_of_match),
924	},
925};
926module_i2c_driver(ltc4162l_driver);
927
928MODULE_LICENSE("GPL");
929MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
930MODULE_DESCRIPTION("LTC4162-L charger driver");
931