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1/*2 * 1-Wire implementation for Maxim Semiconductor3 * MAX7211/MAX17215 standalone fuel gauge chip4 *5 * Copyright (C) 2017 Radioavionica Corporation6 * Author: Alex A. Mihaylov <minimumlaw@rambler.ru>7 *8 * Use consistent with the GNU GPL is permitted,9 * provided that this copyright notice is10 * preserved in its entirety in all copies and derived works.11 *12 */13 14#include <linux/module.h>15#include <linux/slab.h>16#include <linux/w1.h>17#include <linux/regmap.h>18#include <linux/power_supply.h>19 20#define W1_MAX1721X_FAMILY_ID 0x2621#define DEF_DEV_NAME_MAX17211 "MAX17211"22#define DEF_DEV_NAME_MAX17215 "MAX17215"23#define DEF_DEV_NAME_UNKNOWN "UNKNOWN"24#define DEF_MFG_NAME "MAXIM"25 26#define PSY_MAX_NAME_LEN 3227 28/* Number of valid register addresses in W1 mode */29#define MAX1721X_MAX_REG_NR 0x1EF30 31/* Factory settings (nonvolatile registers) (W1 specific) */32#define MAX1721X_REG_NRSENSE 0x1CF /* RSense in 10^-5 Ohm */33/* Strings */34#define MAX1721X_REG_MFG_STR 0x1CC35#define MAX1721X_REG_MFG_NUMB 336#define MAX1721X_REG_DEV_STR 0x1DB37#define MAX1721X_REG_DEV_NUMB 538/* HEX Strings */39#define MAX1721X_REG_SER_HEX 0x1D840 41/* MAX172XX Output Registers for W1 chips */42#define MAX172XX_REG_STATUS 0x000 /* status reg */43#define MAX172XX_BAT_PRESENT (1<<4) /* battery connected bit */44#define MAX172XX_REG_DEVNAME 0x021 /* chip config */45#define MAX172XX_DEV_MASK 0x000F /* chip type mask */46#define MAX172X1_DEV 0x000147#define MAX172X5_DEV 0x000548#define MAX172XX_REG_TEMP 0x008 /* Temperature */49#define MAX172XX_REG_BATT 0x0DA /* Battery voltage */50#define MAX172XX_REG_CURRENT 0x00A /* Actual current */51#define MAX172XX_REG_AVGCURRENT 0x00B /* Average current */52#define MAX172XX_REG_REPSOC 0x006 /* Percentage of charge */53#define MAX172XX_REG_DESIGNCAP 0x018 /* Design capacity */54#define MAX172XX_REG_REPCAP 0x005 /* Average capacity */55#define MAX172XX_REG_TTE 0x011 /* Time to empty */56#define MAX172XX_REG_TTF 0x020 /* Time to full */57 58struct max17211_device_info {59 char name[PSY_MAX_NAME_LEN];60 struct power_supply *bat;61 struct power_supply_desc bat_desc;62 struct device *w1_dev;63 struct regmap *regmap;64 /* battery design format */65 unsigned int rsense; /* in tenths uOhm */66 char DeviceName[2 * MAX1721X_REG_DEV_NUMB + 1];67 char ManufacturerName[2 * MAX1721X_REG_MFG_NUMB + 1];68 char SerialNumber[13]; /* see get_sn_str() later for comment */69};70 71/* Convert regs value to power_supply units */72 73static inline int max172xx_time_to_ps(unsigned int reg)74{75 return reg * 5625 / 1000; /* in sec. */76}77 78static inline int max172xx_percent_to_ps(unsigned int reg)79{80 return reg / 256; /* in percent from 0 to 100 */81}82 83static inline int max172xx_voltage_to_ps(unsigned int reg)84{85 return reg * 1250; /* in uV */86}87 88static inline int max172xx_capacity_to_ps(unsigned int reg)89{90 return reg * 500; /* in uAh */91}92 93/*94 * Current and temperature is signed values, so unsigned regs95 * value must be converted to signed type96 */97 98static inline int max172xx_temperature_to_ps(unsigned int reg)99{100 int val = (int16_t)(reg);101 102 return val * 10 / 256; /* in tenths of deg. C */103}104 105/*106 * Calculating current registers resolution:107 *108 * RSense stored in 10^-5 Ohm, so measurement voltage must be109 * in 10^-11 Volts for get current in uA.110 * 16 bit current reg fullscale +/-51.2mV is 102400 uV.111 * So: 102400 / 65535 * 10^5 = 156252112 */113static inline int max172xx_current_to_voltage(unsigned int reg)114{115 int val = (int16_t)(reg);116 117 return val * 156252;118}119 120 121static inline struct max17211_device_info *122to_device_info(struct power_supply *psy)123{124 return power_supply_get_drvdata(psy);125}126 127static int max1721x_battery_get_property(struct power_supply *psy,128 enum power_supply_property psp,129 union power_supply_propval *val)130{131 struct max17211_device_info *info = to_device_info(psy);132 unsigned int reg = 0;133 int ret = 0;134 135 switch (psp) {136 case POWER_SUPPLY_PROP_PRESENT:137 /*138 * POWER_SUPPLY_PROP_PRESENT will always readable via139 * sysfs interface. Value return 0 if battery not140 * present or unaccessible via W1.141 */142 val->intval =143 regmap_read(info->regmap, MAX172XX_REG_STATUS,144 ®) ? 0 : !(reg & MAX172XX_BAT_PRESENT);145 break;146 case POWER_SUPPLY_PROP_CAPACITY:147 ret = regmap_read(info->regmap, MAX172XX_REG_REPSOC, ®);148 val->intval = max172xx_percent_to_ps(reg);149 break;150 case POWER_SUPPLY_PROP_VOLTAGE_NOW:151 ret = regmap_read(info->regmap, MAX172XX_REG_BATT, ®);152 val->intval = max172xx_voltage_to_ps(reg);153 break;154 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:155 ret = regmap_read(info->regmap, MAX172XX_REG_DESIGNCAP, ®);156 val->intval = max172xx_capacity_to_ps(reg);157 break;158 case POWER_SUPPLY_PROP_CHARGE_AVG:159 ret = regmap_read(info->regmap, MAX172XX_REG_REPCAP, ®);160 val->intval = max172xx_capacity_to_ps(reg);161 break;162 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:163 ret = regmap_read(info->regmap, MAX172XX_REG_TTE, ®);164 val->intval = max172xx_time_to_ps(reg);165 break;166 case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:167 ret = regmap_read(info->regmap, MAX172XX_REG_TTF, ®);168 val->intval = max172xx_time_to_ps(reg);169 break;170 case POWER_SUPPLY_PROP_TEMP:171 ret = regmap_read(info->regmap, MAX172XX_REG_TEMP, ®);172 val->intval = max172xx_temperature_to_ps(reg);173 break;174 /* We need signed current, so must cast info->rsense to signed type */175 case POWER_SUPPLY_PROP_CURRENT_NOW:176 ret = regmap_read(info->regmap, MAX172XX_REG_CURRENT, ®);177 val->intval =178 max172xx_current_to_voltage(reg) / (int)info->rsense;179 break;180 case POWER_SUPPLY_PROP_CURRENT_AVG:181 ret = regmap_read(info->regmap, MAX172XX_REG_AVGCURRENT, ®);182 val->intval =183 max172xx_current_to_voltage(reg) / (int)info->rsense;184 break;185 /*186 * Strings already received and inited by probe.187 * We do dummy read for check battery still available.188 */189 case POWER_SUPPLY_PROP_MODEL_NAME:190 ret = regmap_read(info->regmap, MAX1721X_REG_DEV_STR, ®);191 val->strval = info->DeviceName;192 break;193 case POWER_SUPPLY_PROP_MANUFACTURER:194 ret = regmap_read(info->regmap, MAX1721X_REG_MFG_STR, ®);195 val->strval = info->ManufacturerName;196 break;197 case POWER_SUPPLY_PROP_SERIAL_NUMBER:198 ret = regmap_read(info->regmap, MAX1721X_REG_SER_HEX, ®);199 val->strval = info->SerialNumber;200 break;201 default:202 ret = -EINVAL;203 }204 205 return ret;206}207 208static enum power_supply_property max1721x_battery_props[] = {209 /* int */210 POWER_SUPPLY_PROP_PRESENT,211 POWER_SUPPLY_PROP_CAPACITY,212 POWER_SUPPLY_PROP_VOLTAGE_NOW,213 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,214 POWER_SUPPLY_PROP_CHARGE_AVG,215 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,216 POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,217 POWER_SUPPLY_PROP_TEMP,218 POWER_SUPPLY_PROP_CURRENT_NOW,219 POWER_SUPPLY_PROP_CURRENT_AVG,220 /* strings */221 POWER_SUPPLY_PROP_MODEL_NAME,222 POWER_SUPPLY_PROP_MANUFACTURER,223 POWER_SUPPLY_PROP_SERIAL_NUMBER,224};225 226static int get_string(struct max17211_device_info *info,227 uint16_t reg, uint8_t nr, char *str)228{229 unsigned int val;230 231 if (!str || !(reg == MAX1721X_REG_MFG_STR ||232 reg == MAX1721X_REG_DEV_STR))233 return -EFAULT;234 235 while (nr--) {236 if (regmap_read(info->regmap, reg++, &val))237 return -EFAULT;238 *str++ = val>>8 & 0x00FF;239 *str++ = val & 0x00FF;240 }241 return 0;242}243 244/* Maxim say: Serial number is a hex string up to 12 hex characters */245static int get_sn_string(struct max17211_device_info *info, char *str)246{247 unsigned int val[3];248 249 if (!str)250 return -EFAULT;251 252 if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &val[0]))253 return -EFAULT;254 if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 1, &val[1]))255 return -EFAULT;256 if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 2, &val[2]))257 return -EFAULT;258 259 snprintf(str, 13, "%04X%04X%04X", val[0], val[1], val[2]);260 return 0;261}262 263/*264 * MAX1721x registers description for w1-regmap265 */266static const struct regmap_range max1721x_allow_range[] = {267 regmap_reg_range(0, 0xDF), /* volatile data */268 regmap_reg_range(0x180, 0x1DF), /* non-volatile memory */269 regmap_reg_range(0x1E0, 0x1EF), /* non-volatile history (unused) */270};271 272static const struct regmap_range max1721x_deny_range[] = {273 /* volatile data unused registers */274 regmap_reg_range(0x24, 0x26),275 regmap_reg_range(0x30, 0x31),276 regmap_reg_range(0x33, 0x34),277 regmap_reg_range(0x37, 0x37),278 regmap_reg_range(0x3B, 0x3C),279 regmap_reg_range(0x40, 0x41),280 regmap_reg_range(0x43, 0x44),281 regmap_reg_range(0x47, 0x49),282 regmap_reg_range(0x4B, 0x4C),283 regmap_reg_range(0x4E, 0xAF),284 regmap_reg_range(0xB1, 0xB3),285 regmap_reg_range(0xB5, 0xB7),286 regmap_reg_range(0xBF, 0xD0),287 regmap_reg_range(0xDB, 0xDB),288 /* hole between volatile and non-volatile registers */289 regmap_reg_range(0xE0, 0x17F),290};291 292static const struct regmap_access_table max1721x_regs = {293 .yes_ranges = max1721x_allow_range,294 .n_yes_ranges = ARRAY_SIZE(max1721x_allow_range),295 .no_ranges = max1721x_deny_range,296 .n_no_ranges = ARRAY_SIZE(max1721x_deny_range),297};298 299/*300 * Model Gauge M5 Algorithm output register301 * Volatile data (must not be cached)302 */303static const struct regmap_range max1721x_volatile_allow[] = {304 regmap_reg_range(0, 0xDF),305};306 307static const struct regmap_access_table max1721x_volatile_regs = {308 .yes_ranges = max1721x_volatile_allow,309 .n_yes_ranges = ARRAY_SIZE(max1721x_volatile_allow),310};311 312/*313 * W1-regmap config314 */315static const struct regmap_config max1721x_regmap_w1_config = {316 .reg_bits = 16,317 .val_bits = 16,318 .rd_table = &max1721x_regs,319 .volatile_table = &max1721x_volatile_regs,320 .max_register = MAX1721X_MAX_REG_NR,321};322 323static int devm_w1_max1721x_add_device(struct w1_slave *sl)324{325 struct power_supply_config psy_cfg = {};326 struct max17211_device_info *info;327 328 info = devm_kzalloc(&sl->dev, sizeof(*info), GFP_KERNEL);329 if (!info)330 return -ENOMEM;331 332 sl->family_data = (void *)info;333 info->w1_dev = &sl->dev;334 335 /*336 * power_supply class battery name translated from W1 slave device337 * unique ID (look like 26-0123456789AB) to "max1721x-0123456789AB\0"338 * so, 26 (device family) correspond to max1721x devices.339 * Device name still unique for any number of connected devices.340 */341 snprintf(info->name, sizeof(info->name),342 "max1721x-%012X", (unsigned int)sl->reg_num.id);343 info->bat_desc.name = info->name;344 345 /*346 * FixMe: battery device name exceed max len for thermal_zone device347 * name and translation to thermal_zone must be disabled.348 */349 info->bat_desc.no_thermal = true;350 info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;351 info->bat_desc.properties = max1721x_battery_props;352 info->bat_desc.num_properties = ARRAY_SIZE(max1721x_battery_props);353 info->bat_desc.get_property = max1721x_battery_get_property;354 psy_cfg.drv_data = info;355 356 /* regmap init */357 info->regmap = devm_regmap_init_w1(info->w1_dev,358 &max1721x_regmap_w1_config);359 if (IS_ERR(info->regmap)) {360 int err = PTR_ERR(info->regmap);361 362 dev_err(info->w1_dev, "Failed to allocate register map: %d\n",363 err);364 return err;365 }366 367 /* rsense init */368 info->rsense = 0;369 if (regmap_read(info->regmap, MAX1721X_REG_NRSENSE, &info->rsense)) {370 dev_err(info->w1_dev, "Can't read RSense. Hardware error.\n");371 return -ENODEV;372 }373 374 if (!info->rsense) {375 dev_warn(info->w1_dev, "RSense not calibrated, set 10 mOhms!\n");376 info->rsense = 1000; /* in regs in 10^-5 */377 }378 dev_info(info->w1_dev, "RSense: %d mOhms.\n", info->rsense / 100);379 380 if (get_string(info, MAX1721X_REG_MFG_STR,381 MAX1721X_REG_MFG_NUMB, info->ManufacturerName)) {382 dev_err(info->w1_dev, "Can't read manufacturer. Hardware error.\n");383 return -ENODEV;384 }385 386 if (!info->ManufacturerName[0])387 strscpy(info->ManufacturerName, DEF_MFG_NAME,388 2 * MAX1721X_REG_MFG_NUMB);389 390 if (get_string(info, MAX1721X_REG_DEV_STR,391 MAX1721X_REG_DEV_NUMB, info->DeviceName)) {392 dev_err(info->w1_dev, "Can't read device. Hardware error.\n");393 return -ENODEV;394 }395 if (!info->DeviceName[0]) {396 unsigned int dev_name;397 398 if (regmap_read(info->regmap,399 MAX172XX_REG_DEVNAME, &dev_name)) {400 dev_err(info->w1_dev, "Can't read device name reg.\n");401 return -ENODEV;402 }403 404 switch (dev_name & MAX172XX_DEV_MASK) {405 case MAX172X1_DEV:406 strscpy(info->DeviceName, DEF_DEV_NAME_MAX17211,407 2 * MAX1721X_REG_DEV_NUMB);408 break;409 case MAX172X5_DEV:410 strscpy(info->DeviceName, DEF_DEV_NAME_MAX17215,411 2 * MAX1721X_REG_DEV_NUMB);412 break;413 default:414 strscpy(info->DeviceName, DEF_DEV_NAME_UNKNOWN,415 2 * MAX1721X_REG_DEV_NUMB);416 }417 }418 419 if (get_sn_string(info, info->SerialNumber)) {420 dev_err(info->w1_dev, "Can't read serial. Hardware error.\n");421 return -ENODEV;422 }423 424 info->bat = devm_power_supply_register(&sl->dev, &info->bat_desc,425 &psy_cfg);426 if (IS_ERR(info->bat)) {427 dev_err(info->w1_dev, "failed to register battery\n");428 return PTR_ERR(info->bat);429 }430 431 return 0;432}433 434static const struct w1_family_ops w1_max1721x_fops = {435 .add_slave = devm_w1_max1721x_add_device,436};437 438static struct w1_family w1_max1721x_family = {439 .fid = W1_MAX1721X_FAMILY_ID,440 .fops = &w1_max1721x_fops,441};442 443module_w1_family(w1_max1721x_family);444 445MODULE_LICENSE("GPL");446MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>");447MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauge IC driver");448MODULE_ALIAS("w1-family-" __stringify(W1_MAX1721X_FAMILY_ID));449