1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Fuel gauge driver for Maxim 17201/17205
4  *
5  * based on max1721x_battery.c
6  *
7  * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/i2c.h>
12 #include <linux/module.h>
13 #include <linux/nvmem-provider.h>
14 #include <linux/power_supply.h>
15 #include <linux/regmap.h>
16 
17 #include <linux/unaligned.h>
18 
19 /* SBS compliant registers */
20 #define MAX172XX_TEMP1			0x34
21 #define MAX172XX_INT_TEMP		0x35
22 #define MAX172XX_TEMP2			0x3B
23 
24 /* Nonvolatile registers */
25 #define MAX1720X_NXTABLE0		0x80
26 #define MAX1720X_NRSENSE		0xCF	/* RSense in 10^-5 Ohm */
27 #define MAX1720X_NDEVICE_NAME4		0xDF
28 
29 /* ModelGauge m5 */
30 #define MAX172XX_STATUS			0x00	/* Status */
31 #define MAX172XX_STATUS_BAT_ABSENT	BIT(3)	/* Battery absent */
32 #define MAX172XX_STATUS_IMX		BIT(6)	/* Maximum Current Alert Threshold Exceeded */
33 #define MAX172XX_STATUS_VMN		BIT(8)	/* Minimum Voltage Alert Threshold Exceeded */
34 #define MAX172XX_STATUS_TMN		BIT(9)	/* Minimum Temperature Alert Threshold Exceeded */
35 #define MAX172XX_STATUS_VMX		BIT(12)	/* Maximum Voltage Alert Threshold Exceeded */
36 #define MAX172XX_STATUS_TMX		BIT(13)	/* Maximum Temperature Alert Threshold Exceeded */
37 #define MAX172XX_REPCAP			0x05	/* Average capacity */
38 #define MAX172XX_REPSOC			0x06	/* Percentage of charge */
39 #define MAX172XX_TEMP			0x08	/* Temperature */
40 #define MAX172XX_CURRENT		0x0A	/* Actual current */
41 #define MAX172XX_AVG_CURRENT		0x0B	/* Average current */
42 #define MAX172XX_FULL_CAP		0x10	/* Calculated full capacity */
43 #define MAX172XX_TTE			0x11	/* Time to empty */
44 #define MAX172XX_AVG_TA			0x16	/* Average temperature */
45 #define MAX172XX_CYCLES			0x17
46 #define MAX172XX_DESIGN_CAP		0x18	/* Design capacity */
47 #define MAX172XX_AVG_VCELL		0x19
48 #define MAX172XX_TTF			0x20	/* Time to full */
49 #define MAX172XX_DEV_NAME		0x21	/* Device name */
50 #define MAX172XX_DEV_NAME_TYPE_MASK	GENMASK(3, 0)
51 #define MAX172XX_DEV_NAME_TYPE_MAX17201	BIT(0)
52 #define MAX172XX_DEV_NAME_TYPE_MAX17205	(BIT(0) | BIT(2))
53 #define MAX172XX_QR_TABLE10		0x22
54 #define MAX172XX_BATT			0xDA	/* Battery voltage */
55 #define MAX172XX_ATAVCAP		0xDF
56 
57 static const char *const max1720x_manufacturer = "Maxim Integrated";
58 static const char *const max17201_model = "MAX17201";
59 static const char *const max17205_model = "MAX17205";
60 
61 struct max1720x_device_info {
62 	struct regmap *regmap;
63 	struct regmap *regmap_nv;
64 	struct i2c_client *ancillary;
65 	int rsense;
66 };
67 
68 /*
69  * Model Gauge M5 Algorithm output register
70  * Volatile data (must not be cached)
71  */
72 static const struct regmap_range max1720x_volatile_allow[] = {
73 	regmap_reg_range(MAX172XX_STATUS, MAX172XX_CYCLES),
74 	regmap_reg_range(MAX172XX_AVG_VCELL, MAX172XX_TTF),
75 	regmap_reg_range(MAX172XX_QR_TABLE10, MAX172XX_ATAVCAP),
76 };
77 
78 static const struct regmap_range max1720x_readable_allow[] = {
79 	regmap_reg_range(MAX172XX_STATUS, MAX172XX_ATAVCAP),
80 };
81 
82 static const struct regmap_range max1720x_readable_deny[] = {
83 	/* unused registers */
84 	regmap_reg_range(0x24, 0x26),
85 	regmap_reg_range(0x30, 0x31),
86 	regmap_reg_range(0x33, 0x34),
87 	regmap_reg_range(0x37, 0x37),
88 	regmap_reg_range(0x3B, 0x3C),
89 	regmap_reg_range(0x40, 0x41),
90 	regmap_reg_range(0x43, 0x44),
91 	regmap_reg_range(0x47, 0x49),
92 	regmap_reg_range(0x4B, 0x4C),
93 	regmap_reg_range(0x4E, 0xAF),
94 	regmap_reg_range(0xB1, 0xB3),
95 	regmap_reg_range(0xB5, 0xB7),
96 	regmap_reg_range(0xBF, 0xD0),
97 	regmap_reg_range(0xDB, 0xDB),
98 	regmap_reg_range(0xE0, 0xFF),
99 };
100 
101 static const struct regmap_access_table max1720x_readable_regs = {
102 	.yes_ranges	= max1720x_readable_allow,
103 	.n_yes_ranges	= ARRAY_SIZE(max1720x_readable_allow),
104 	.no_ranges	= max1720x_readable_deny,
105 	.n_no_ranges	= ARRAY_SIZE(max1720x_readable_deny),
106 };
107 
108 static const struct regmap_access_table max1720x_volatile_regs = {
109 	.yes_ranges	= max1720x_volatile_allow,
110 	.n_yes_ranges	= ARRAY_SIZE(max1720x_volatile_allow),
111 	.no_ranges	= max1720x_readable_deny,
112 	.n_no_ranges	= ARRAY_SIZE(max1720x_readable_deny),
113 };
114 
115 static const struct regmap_config max1720x_regmap_cfg = {
116 	.reg_bits = 8,
117 	.val_bits = 16,
118 	.max_register = MAX172XX_ATAVCAP,
119 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
120 	.rd_table = &max1720x_readable_regs,
121 	.volatile_table = &max1720x_volatile_regs,
122 	.cache_type = REGCACHE_MAPLE,
123 };
124 
125 static const struct regmap_range max1720x_nvmem_allow[] = {
126 	regmap_reg_range(MAX172XX_TEMP1, MAX172XX_INT_TEMP),
127 	regmap_reg_range(MAX172XX_TEMP2, MAX172XX_TEMP2),
128 	regmap_reg_range(MAX1720X_NXTABLE0, MAX1720X_NDEVICE_NAME4),
129 };
130 
131 static const struct regmap_range max1720x_nvmem_deny[] = {
132 	regmap_reg_range(0x00, 0x33),
133 	regmap_reg_range(0x36, 0x3A),
134 	regmap_reg_range(0x3C, 0x7F),
135 	regmap_reg_range(0xE0, 0xFF),
136 };
137 
138 static const struct regmap_access_table max1720x_nvmem_regs = {
139 	.yes_ranges	= max1720x_nvmem_allow,
140 	.n_yes_ranges	= ARRAY_SIZE(max1720x_nvmem_allow),
141 	.no_ranges	= max1720x_nvmem_deny,
142 	.n_no_ranges	= ARRAY_SIZE(max1720x_nvmem_deny),
143 };
144 
145 static const struct regmap_config max1720x_nvmem_regmap_cfg = {
146 	.reg_bits = 8,
147 	.val_bits = 16,
148 	.max_register = MAX1720X_NDEVICE_NAME4,
149 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
150 	.rd_table = &max1720x_nvmem_regs,
151 };
152 
153 static const struct nvmem_cell_info max1720x_nvmem_cells[] = {
154 	{ .name = "nXTable0",  .offset = 0,  .bytes = 2, },
155 	{ .name = "nXTable1",  .offset = 2,  .bytes = 2, },
156 	{ .name = "nXTable2",  .offset = 4,  .bytes = 2, },
157 	{ .name = "nXTable3",  .offset = 6,  .bytes = 2, },
158 	{ .name = "nXTable4",  .offset = 8,  .bytes = 2, },
159 	{ .name = "nXTable5",  .offset = 10, .bytes = 2, },
160 	{ .name = "nXTable6",  .offset = 12, .bytes = 2, },
161 	{ .name = "nXTable7",  .offset = 14, .bytes = 2, },
162 	{ .name = "nXTable8",  .offset = 16, .bytes = 2, },
163 	{ .name = "nXTable9",  .offset = 18, .bytes = 2, },
164 	{ .name = "nXTable10", .offset = 20, .bytes = 2, },
165 	{ .name = "nXTable11", .offset = 22, .bytes = 2, },
166 	{ .name = "nUser18C",  .offset = 24, .bytes = 2, },
167 	{ .name = "nUser18D",  .offset = 26, .bytes = 2, },
168 	{ .name = "nODSCTh",   .offset = 28, .bytes = 2, },
169 	{ .name = "nODSCCfg",  .offset = 30, .bytes = 2, },
170 
171 	{ .name = "nOCVTable0",  .offset = 32, .bytes = 2, },
172 	{ .name = "nOCVTable1",  .offset = 34, .bytes = 2, },
173 	{ .name = "nOCVTable2",  .offset = 36, .bytes = 2, },
174 	{ .name = "nOCVTable3",  .offset = 38, .bytes = 2, },
175 	{ .name = "nOCVTable4",  .offset = 40, .bytes = 2, },
176 	{ .name = "nOCVTable5",  .offset = 42, .bytes = 2, },
177 	{ .name = "nOCVTable6",  .offset = 44, .bytes = 2, },
178 	{ .name = "nOCVTable7",  .offset = 46, .bytes = 2, },
179 	{ .name = "nOCVTable8",  .offset = 48, .bytes = 2, },
180 	{ .name = "nOCVTable9",  .offset = 50, .bytes = 2, },
181 	{ .name = "nOCVTable10", .offset = 52, .bytes = 2, },
182 	{ .name = "nOCVTable11", .offset = 54, .bytes = 2, },
183 	{ .name = "nIChgTerm",   .offset = 56, .bytes = 2, },
184 	{ .name = "nFilterCfg",  .offset = 58, .bytes = 2, },
185 	{ .name = "nVEmpty",     .offset = 60, .bytes = 2, },
186 	{ .name = "nLearnCfg",   .offset = 62, .bytes = 2, },
187 
188 	{ .name = "nQRTable00",  .offset = 64, .bytes = 2, },
189 	{ .name = "nQRTable10",  .offset = 66, .bytes = 2, },
190 	{ .name = "nQRTable20",  .offset = 68, .bytes = 2, },
191 	{ .name = "nQRTable30",  .offset = 70, .bytes = 2, },
192 	{ .name = "nCycles",     .offset = 72, .bytes = 2, },
193 	{ .name = "nFullCapNom", .offset = 74, .bytes = 2, },
194 	{ .name = "nRComp0",     .offset = 76, .bytes = 2, },
195 	{ .name = "nTempCo",     .offset = 78, .bytes = 2, },
196 	{ .name = "nIAvgEmpty",  .offset = 80, .bytes = 2, },
197 	{ .name = "nFullCapRep", .offset = 82, .bytes = 2, },
198 	{ .name = "nVoltTemp",   .offset = 84, .bytes = 2, },
199 	{ .name = "nMaxMinCurr", .offset = 86, .bytes = 2, },
200 	{ .name = "nMaxMinVolt", .offset = 88, .bytes = 2, },
201 	{ .name = "nMaxMinTemp", .offset = 90, .bytes = 2, },
202 	{ .name = "nSOC",        .offset = 92, .bytes = 2, },
203 	{ .name = "nTimerH",     .offset = 94, .bytes = 2, },
204 
205 	{ .name = "nConfig",    .offset = 96,  .bytes = 2, },
206 	{ .name = "nRippleCfg", .offset = 98,  .bytes = 2, },
207 	{ .name = "nMiscCfg",   .offset = 100, .bytes = 2, },
208 	{ .name = "nDesignCap", .offset = 102, .bytes = 2, },
209 	{ .name = "nHibCfg",    .offset = 104, .bytes = 2, },
210 	{ .name = "nPackCfg",   .offset = 106, .bytes = 2, },
211 	{ .name = "nRelaxCfg",  .offset = 108, .bytes = 2, },
212 	{ .name = "nConvgCfg",  .offset = 110, .bytes = 2, },
213 	{ .name = "nNVCfg0",    .offset = 112, .bytes = 2, },
214 	{ .name = "nNVCfg1",    .offset = 114, .bytes = 2, },
215 	{ .name = "nNVCfg2",    .offset = 116, .bytes = 2, },
216 	{ .name = "nSBSCfg",    .offset = 118, .bytes = 2, },
217 	{ .name = "nROMID0",    .offset = 120, .bytes = 2, },
218 	{ .name = "nROMID1",    .offset = 122, .bytes = 2, },
219 	{ .name = "nROMID2",    .offset = 124, .bytes = 2, },
220 	{ .name = "nROMID3",    .offset = 126, .bytes = 2, },
221 
222 	{ .name = "nVAlrtTh",      .offset = 128, .bytes = 2, },
223 	{ .name = "nTAlrtTh",      .offset = 130, .bytes = 2, },
224 	{ .name = "nSAlrtTh",      .offset = 132, .bytes = 2, },
225 	{ .name = "nIAlrtTh",      .offset = 134, .bytes = 2, },
226 	{ .name = "nUser1C4",      .offset = 136, .bytes = 2, },
227 	{ .name = "nUser1C5",      .offset = 138, .bytes = 2, },
228 	{ .name = "nFullSOCThr",   .offset = 140, .bytes = 2, },
229 	{ .name = "nTTFCfg",       .offset = 142, .bytes = 2, },
230 	{ .name = "nCGain",        .offset = 144, .bytes = 2, },
231 	{ .name = "nTCurve",       .offset = 146, .bytes = 2, },
232 	{ .name = "nTGain",        .offset = 148, .bytes = 2, },
233 	{ .name = "nTOff",         .offset = 150, .bytes = 2, },
234 	{ .name = "nManfctrName0", .offset = 152, .bytes = 2, },
235 	{ .name = "nManfctrName1", .offset = 154, .bytes = 2, },
236 	{ .name = "nManfctrName2", .offset = 156, .bytes = 2, },
237 	{ .name = "nRSense",       .offset = 158, .bytes = 2, },
238 
239 	{ .name = "nUser1D0",       .offset = 160, .bytes = 2, },
240 	{ .name = "nUser1D1",       .offset = 162, .bytes = 2, },
241 	{ .name = "nAgeFcCfg",      .offset = 164, .bytes = 2, },
242 	{ .name = "nDesignVoltage", .offset = 166, .bytes = 2, },
243 	{ .name = "nUser1D4",       .offset = 168, .bytes = 2, },
244 	{ .name = "nRFastVShdn",    .offset = 170, .bytes = 2, },
245 	{ .name = "nManfctrDate",   .offset = 172, .bytes = 2, },
246 	{ .name = "nFirstUsed",     .offset = 174, .bytes = 2, },
247 	{ .name = "nSerialNumber0", .offset = 176, .bytes = 2, },
248 	{ .name = "nSerialNumber1", .offset = 178, .bytes = 2, },
249 	{ .name = "nSerialNumber2", .offset = 180, .bytes = 2, },
250 	{ .name = "nDeviceName0",   .offset = 182, .bytes = 2, },
251 	{ .name = "nDeviceName1",   .offset = 184, .bytes = 2, },
252 	{ .name = "nDeviceName2",   .offset = 186, .bytes = 2, },
253 	{ .name = "nDeviceName3",   .offset = 188, .bytes = 2, },
254 	{ .name = "nDeviceName4",   .offset = 190, .bytes = 2, },
255 };
256 
257 static const enum power_supply_property max1720x_battery_props[] = {
258 	POWER_SUPPLY_PROP_HEALTH,
259 	POWER_SUPPLY_PROP_PRESENT,
260 	POWER_SUPPLY_PROP_CAPACITY,
261 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
262 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
263 	POWER_SUPPLY_PROP_CHARGE_AVG,
264 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
265 	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
266 	POWER_SUPPLY_PROP_TEMP,
267 	POWER_SUPPLY_PROP_CURRENT_NOW,
268 	POWER_SUPPLY_PROP_CURRENT_AVG,
269 	POWER_SUPPLY_PROP_CHARGE_FULL,
270 	POWER_SUPPLY_PROP_MODEL_NAME,
271 	POWER_SUPPLY_PROP_MANUFACTURER,
272 };
273 
274 /* Convert regs value to power_supply units */
275 
max172xx_time_to_ps(unsigned int reg)276 static int max172xx_time_to_ps(unsigned int reg)
277 {
278 	return reg * 5625 / 1000;	/* in sec. */
279 }
280 
max172xx_percent_to_ps(unsigned int reg)281 static int max172xx_percent_to_ps(unsigned int reg)
282 {
283 	return reg / 256;	/* in percent from 0 to 100 */
284 }
285 
max172xx_voltage_to_ps(unsigned int reg)286 static int max172xx_voltage_to_ps(unsigned int reg)
287 {
288 	return reg * 1250;	/* in uV */
289 }
290 
max172xx_capacity_to_ps(unsigned int reg)291 static int max172xx_capacity_to_ps(unsigned int reg)
292 {
293 	return reg * 500;	/* in uAh */
294 }
295 
296 /*
297  * Current and temperature is signed values, so unsigned regs
298  * value must be converted to signed type
299  */
300 
max172xx_temperature_to_ps(unsigned int reg)301 static int max172xx_temperature_to_ps(unsigned int reg)
302 {
303 	int val = (int16_t)reg;
304 
305 	return val * 10 / 256; /* in tenths of deg. C */
306 }
307 
308 /*
309  * Calculating current registers resolution:
310  *
311  * RSense stored in 10^-5 Ohm, so measurement voltage must be
312  * in 10^-11 Volts for get current in uA.
313  * 16 bit current reg fullscale +/-51.2mV is 102400 uV.
314  * So: 102400 / 65535 * 10^5 = 156252
315  */
max172xx_current_to_voltage(unsigned int reg)316 static int max172xx_current_to_voltage(unsigned int reg)
317 {
318 	int val = (int16_t)reg;
319 
320 	return val * 156252;
321 }
322 
max172xx_battery_health(struct max1720x_device_info * info,unsigned int * health)323 static int max172xx_battery_health(struct max1720x_device_info *info,
324 				   unsigned int *health)
325 {
326 	unsigned int status;
327 	int ret;
328 
329 	ret = regmap_read(info->regmap, MAX172XX_STATUS, &status);
330 	if (ret < 0)
331 		return ret;
332 
333 	if (status & MAX172XX_STATUS_VMN)
334 		*health = POWER_SUPPLY_HEALTH_DEAD;
335 	else if (status & MAX172XX_STATUS_VMX)
336 		*health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
337 	else if (status & MAX172XX_STATUS_TMN)
338 		*health = POWER_SUPPLY_HEALTH_COLD;
339 	else if (status & MAX172XX_STATUS_TMX)
340 		*health = POWER_SUPPLY_HEALTH_OVERHEAT;
341 	else if (status & MAX172XX_STATUS_IMX)
342 		*health = POWER_SUPPLY_HEALTH_OVERCURRENT;
343 	else
344 		*health = POWER_SUPPLY_HEALTH_GOOD;
345 
346 	/* Clear events which are not self-clearing to detect next events */
347 	if (status > 0 && status != MAX172XX_STATUS_IMX) {
348 		ret = regmap_set_bits(info->regmap, MAX172XX_STATUS,
349 				      MAX172XX_STATUS_VMN |
350 				      MAX172XX_STATUS_VMX |
351 				      MAX172XX_STATUS_TMN |
352 				      MAX172XX_STATUS_TMX);
353 		if (ret < 0)
354 			return ret;
355 	}
356 
357 	return 0;
358 }
359 
max1720x_battery_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)360 static int max1720x_battery_get_property(struct power_supply *psy,
361 					 enum power_supply_property psp,
362 					 union power_supply_propval *val)
363 {
364 	struct max1720x_device_info *info = power_supply_get_drvdata(psy);
365 	unsigned int reg_val;
366 	int ret = 0;
367 
368 	switch (psp) {
369 	case POWER_SUPPLY_PROP_HEALTH:
370 		ret = max172xx_battery_health(info, &reg_val);
371 		val->intval = reg_val;
372 		break;
373 	case POWER_SUPPLY_PROP_PRESENT:
374 		/*
375 		 * POWER_SUPPLY_PROP_PRESENT will always readable via
376 		 * sysfs interface. Value return 0 if battery not
377 		 * present or unaccesable via I2c.
378 		 */
379 		ret = regmap_read(info->regmap, MAX172XX_STATUS, &reg_val);
380 		if (ret < 0) {
381 			val->intval = 0;
382 			return 0;
383 		}
384 
385 		val->intval = !FIELD_GET(MAX172XX_STATUS_BAT_ABSENT, reg_val);
386 		break;
387 	case POWER_SUPPLY_PROP_CAPACITY:
388 		ret = regmap_read(info->regmap, MAX172XX_REPSOC, &reg_val);
389 		val->intval = max172xx_percent_to_ps(reg_val);
390 		break;
391 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
392 		ret = regmap_read(info->regmap, MAX172XX_BATT, &reg_val);
393 		val->intval = max172xx_voltage_to_ps(reg_val);
394 		break;
395 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
396 		ret = regmap_read(info->regmap, MAX172XX_DESIGN_CAP, &reg_val);
397 		val->intval = max172xx_capacity_to_ps(reg_val);
398 		break;
399 	case POWER_SUPPLY_PROP_CHARGE_AVG:
400 		ret = regmap_read(info->regmap, MAX172XX_REPCAP, &reg_val);
401 		val->intval = max172xx_capacity_to_ps(reg_val);
402 		break;
403 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
404 		ret = regmap_read(info->regmap, MAX172XX_TTE, &reg_val);
405 		val->intval = max172xx_time_to_ps(reg_val);
406 		break;
407 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
408 		ret = regmap_read(info->regmap, MAX172XX_TTF, &reg_val);
409 		val->intval = max172xx_time_to_ps(reg_val);
410 		break;
411 	case POWER_SUPPLY_PROP_TEMP:
412 		ret = regmap_read(info->regmap, MAX172XX_TEMP, &reg_val);
413 		val->intval = max172xx_temperature_to_ps(reg_val);
414 		break;
415 	case POWER_SUPPLY_PROP_CURRENT_NOW:
416 		ret = regmap_read(info->regmap, MAX172XX_CURRENT, &reg_val);
417 		val->intval = max172xx_current_to_voltage(reg_val) / info->rsense;
418 		break;
419 	case POWER_SUPPLY_PROP_CURRENT_AVG:
420 		ret = regmap_read(info->regmap, MAX172XX_AVG_CURRENT, &reg_val);
421 		val->intval = max172xx_current_to_voltage(reg_val) / info->rsense;
422 		break;
423 	case POWER_SUPPLY_PROP_CHARGE_FULL:
424 		ret = regmap_read(info->regmap, MAX172XX_FULL_CAP, &reg_val);
425 		val->intval = max172xx_capacity_to_ps(reg_val);
426 		break;
427 	case POWER_SUPPLY_PROP_MODEL_NAME:
428 		ret = regmap_read(info->regmap, MAX172XX_DEV_NAME, &reg_val);
429 		reg_val = FIELD_GET(MAX172XX_DEV_NAME_TYPE_MASK, reg_val);
430 		if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17201)
431 			val->strval = max17201_model;
432 		else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205)
433 			val->strval = max17205_model;
434 		else
435 			return -ENODEV;
436 		break;
437 	case POWER_SUPPLY_PROP_MANUFACTURER:
438 		val->strval = max1720x_manufacturer;
439 		break;
440 	default:
441 		return -EINVAL;
442 	}
443 
444 	return ret;
445 }
446 
max1720x_read_temp(struct device * dev,u8 reg,char * buf)447 static int max1720x_read_temp(struct device *dev, u8 reg, char *buf)
448 {
449 	struct power_supply *psy = dev_get_drvdata(dev);
450 	struct max1720x_device_info *info = power_supply_get_drvdata(psy);
451 	unsigned int val;
452 	int ret;
453 
454 	ret = regmap_read(info->regmap_nv, reg, &val);
455 	if (ret < 0)
456 		return ret;
457 
458 	/*
459 	 * Temperature in degrees Celsius starting at absolute zero, -273C or
460 	 * 0K with an LSb of 0.1C
461 	 */
462 	return sysfs_emit(buf, "%d\n", val - 2730);
463 }
464 
temp_ain1_show(struct device * dev,struct device_attribute * attr,char * buf)465 static ssize_t temp_ain1_show(struct device *dev, struct device_attribute *attr,
466 			      char *buf)
467 {
468 	return max1720x_read_temp(dev, MAX172XX_TEMP1, buf);
469 }
470 
temp_ain2_show(struct device * dev,struct device_attribute * attr,char * buf)471 static ssize_t temp_ain2_show(struct device *dev, struct device_attribute *attr,
472 			      char *buf)
473 {
474 	return max1720x_read_temp(dev, MAX172XX_TEMP2, buf);
475 }
476 
temp_int_show(struct device * dev,struct device_attribute * attr,char * buf)477 static ssize_t temp_int_show(struct device *dev, struct device_attribute *attr,
478 			     char *buf)
479 {
480 	return max1720x_read_temp(dev, MAX172XX_INT_TEMP, buf);
481 }
482 
483 static DEVICE_ATTR_RO(temp_ain1);
484 static DEVICE_ATTR_RO(temp_ain2);
485 static DEVICE_ATTR_RO(temp_int);
486 
487 static struct attribute *max1720x_attrs[] = {
488 	&dev_attr_temp_ain1.attr,
489 	&dev_attr_temp_ain2.attr,
490 	&dev_attr_temp_int.attr,
491 	NULL
492 };
493 ATTRIBUTE_GROUPS(max1720x);
494 
495 static
max1720x_nvmem_reg_read(void * priv,unsigned int off,void * val,size_t len)496 int max1720x_nvmem_reg_read(void *priv, unsigned int off, void *val, size_t len)
497 {
498 	struct max1720x_device_info *info = priv;
499 	unsigned int reg = MAX1720X_NXTABLE0 + (off / 2);
500 
501 	return regmap_bulk_read(info->regmap_nv, reg, val, len / 2);
502 }
503 
max1720x_unregister_ancillary(void * data)504 static void max1720x_unregister_ancillary(void *data)
505 {
506 	struct max1720x_device_info *info = data;
507 
508 	i2c_unregister_device(info->ancillary);
509 }
510 
max1720x_probe_nvmem(struct i2c_client * client,struct max1720x_device_info * info)511 static int max1720x_probe_nvmem(struct i2c_client *client,
512 				struct max1720x_device_info *info)
513 {
514 	struct device *dev = &client->dev;
515 	struct nvmem_config nvmem_config = {
516 		.dev = dev,
517 		.name = "max1720x_nvmem",
518 		.cells = max1720x_nvmem_cells,
519 		.ncells = ARRAY_SIZE(max1720x_nvmem_cells),
520 		.read_only = true,
521 		.root_only = true,
522 		.reg_read = max1720x_nvmem_reg_read,
523 		.size = ARRAY_SIZE(max1720x_nvmem_cells) * 2,
524 		.word_size = 2,
525 		.stride = 2,
526 		.priv = info,
527 	};
528 	struct nvmem_device *nvmem;
529 	unsigned int val;
530 	int ret;
531 
532 	info->ancillary = i2c_new_ancillary_device(client, "nvmem", 0xb);
533 	if (IS_ERR(info->ancillary)) {
534 		dev_err(dev, "Failed to initialize ancillary i2c device\n");
535 		return PTR_ERR(info->ancillary);
536 	}
537 
538 	ret = devm_add_action_or_reset(dev, max1720x_unregister_ancillary, info);
539 	if (ret) {
540 		dev_err(dev, "Failed to add unregister callback\n");
541 		return ret;
542 	}
543 
544 	info->regmap_nv = devm_regmap_init_i2c(info->ancillary,
545 					       &max1720x_nvmem_regmap_cfg);
546 	if (IS_ERR(info->regmap_nv)) {
547 		dev_err(dev, "regmap initialization of nvmem failed\n");
548 		return PTR_ERR(info->regmap_nv);
549 	}
550 
551 	ret = regmap_read(info->regmap_nv, MAX1720X_NRSENSE, &val);
552 	if (ret < 0) {
553 		dev_err(dev, "Failed to read sense resistor value\n");
554 		return ret;
555 	}
556 
557 	info->rsense = val;
558 	if (!info->rsense) {
559 		dev_warn(dev, "RSense not calibrated, set 10 mOhms!\n");
560 		info->rsense = 1000; /* in regs in 10^-5 */
561 	}
562 
563 	nvmem = devm_nvmem_register(dev, &nvmem_config);
564 	if (IS_ERR(nvmem)) {
565 		dev_err(dev, "Could not register nvmem!");
566 		return PTR_ERR(nvmem);
567 	}
568 
569 	return 0;
570 }
571 
572 static const struct power_supply_desc max1720x_bat_desc = {
573 	.name = "max1720x",
574 	.no_thermal = true,
575 	.type = POWER_SUPPLY_TYPE_BATTERY,
576 	.properties = max1720x_battery_props,
577 	.num_properties = ARRAY_SIZE(max1720x_battery_props),
578 	.get_property = max1720x_battery_get_property,
579 };
580 
max1720x_probe(struct i2c_client * client)581 static int max1720x_probe(struct i2c_client *client)
582 {
583 	struct power_supply_config psy_cfg = {};
584 	struct device *dev = &client->dev;
585 	struct max1720x_device_info *info;
586 	struct power_supply *bat;
587 	int ret;
588 
589 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
590 	if (!info)
591 		return -ENOMEM;
592 
593 	psy_cfg.drv_data = info;
594 	psy_cfg.fwnode = dev_fwnode(dev);
595 	psy_cfg.attr_grp = max1720x_groups;
596 	i2c_set_clientdata(client, info);
597 	info->regmap = devm_regmap_init_i2c(client, &max1720x_regmap_cfg);
598 	if (IS_ERR(info->regmap))
599 		return dev_err_probe(dev, PTR_ERR(info->regmap),
600 				     "regmap initialization failed\n");
601 
602 	ret = max1720x_probe_nvmem(client, info);
603 	if (ret)
604 		return dev_err_probe(dev, ret, "Failed to probe nvmem\n");
605 
606 	bat = devm_power_supply_register(dev, &max1720x_bat_desc, &psy_cfg);
607 	if (IS_ERR(bat))
608 		return dev_err_probe(dev, PTR_ERR(bat),
609 				     "Failed to register power supply\n");
610 
611 	return 0;
612 }
613 
614 static const struct of_device_id max1720x_of_match[] = {
615 	{ .compatible = "maxim,max17201" },
616 	{}
617 };
618 MODULE_DEVICE_TABLE(of, max1720x_of_match);
619 
620 static struct i2c_driver max1720x_i2c_driver = {
621 	.driver = {
622 		.name = "max1720x",
623 		.of_match_table = max1720x_of_match,
624 	},
625 	.probe = max1720x_probe,
626 };
627 module_i2c_driver(max1720x_i2c_driver);
628 
629 MODULE_LICENSE("GPL");
630 MODULE_AUTHOR("Dimitri Fedrau <dima.fedrau@gmail.com>");
631 MODULE_DESCRIPTION("Maxim MAX17201/MAX17205 Fuel Gauge IC driver");
632