drivers/power/supply/max1721x_battery.c - linux - Git at Google

 /*
  * 1-Wire implementation for Maxim Semiconductor
  * MAX7211/MAX17215 standalone fuel gauge chip
  *
  * Copyright (C) 2017 Radioavionica Corporation
  * Author: Alex A. Mihaylov <minimumlaw@rambler.ru>
  *
  * Use consistent with the GNU GPL is permitted,
  * provided that this copyright notice is
  * preserved in its entirety in all copies and derived works.
  *
  */

 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/w1.h>
 #include <linux/regmap.h>
 #include <linux/power_supply.h>

 #define W1_MAX1721X_FAMILY_ID		0x26
 #define DEF_DEV_NAME_MAX17211		"MAX17211"
 #define DEF_DEV_NAME_MAX17215		"MAX17215"
 #define DEF_DEV_NAME_UNKNOWN		"UNKNOWN"
 #define DEF_MFG_NAME			"MAXIM"

 #define PSY_MAX_NAME_LEN	32

 /* Number of valid register addresses in W1 mode */
 #define MAX1721X_MAX_REG_NR	0x1EF

 /* Factory settings (nonvolatile registers) (W1 specific) */
 #define MAX1721X_REG_NRSENSE	0x1CF	/* RSense in 10^-5 Ohm */
 /* Strings */
 #define MAX1721X_REG_MFG_STR	0x1CC
 #define MAX1721X_REG_MFG_NUMB	3
 #define MAX1721X_REG_DEV_STR	0x1DB
 #define MAX1721X_REG_DEV_NUMB	5
 /* HEX Strings */
 #define MAX1721X_REG_SER_HEX	0x1D8

 /* MAX172XX Output Registers for W1 chips */
 #define MAX172XX_REG_STATUS	0x000	/* status reg */
 #define MAX172XX_BAT_PRESENT	(1<<4)	/* battery connected bit */
 #define MAX172XX_REG_DEVNAME	0x021	/* chip config */
 #define MAX172XX_DEV_MASK	0x000F	/* chip type mask */
 #define MAX172X1_DEV		0x0001
 #define MAX172X5_DEV		0x0005
 #define MAX172XX_REG_TEMP	0x008	/* Temperature */
 #define MAX172XX_REG_BATT	0x0DA	/* Battery voltage */
 #define MAX172XX_REG_CURRENT	0x00A	/* Actual current */
 #define MAX172XX_REG_AVGCURRENT	0x00B	/* Average current */
 #define MAX172XX_REG_REPSOC	0x006	/* Percentage of charge */
 #define MAX172XX_REG_DESIGNCAP	0x018	/* Design capacity */
 #define MAX172XX_REG_REPCAP	0x005	/* Average capacity */
 #define MAX172XX_REG_TTE	0x011	/* Time to empty */
 #define MAX172XX_REG_TTF	0x020	/* Time to full */

 struct max17211_device_info {
 	char name[PSY_MAX_NAME_LEN];
 	struct power_supply *bat;
 	struct power_supply_desc bat_desc;
 	struct device *w1_dev;
 	struct regmap *regmap;
 	/* battery design format */
 	unsigned int rsense; /* in tenths uOhm */
 	char DeviceName[2 * MAX1721X_REG_DEV_NUMB + 1];
 	char ManufacturerName[2 * MAX1721X_REG_MFG_NUMB + 1];
 	char SerialNumber[13]; /* see get_sn_str() later for comment */
 };

 /* Convert regs value to power_supply units */

 static inline int max172xx_time_to_ps(unsigned int reg)
 {
 	return reg * 5625 / 1000;	/* in sec. */
 }

 static inline int max172xx_percent_to_ps(unsigned int reg)
 {
 	return reg / 256;	/* in percent from 0 to 100 */
 }

 static inline int max172xx_voltage_to_ps(unsigned int reg)
 {
 	return reg * 1250;	/* in uV */
 }

 static inline int max172xx_capacity_to_ps(unsigned int reg)
 {
 	return reg * 500;	/* in uAh */
 }

 /*
  * Current and temperature is signed values, so unsigned regs
  * value must be converted to signed type
  */

 static inline int max172xx_temperature_to_ps(unsigned int reg)
 {
 	int val = (int16_t)(reg);

 	return val * 10 / 256; /* in tenths of deg. C */
 }

 /*
  * Calculating current registers resolution:
  *
  * RSense stored in 10^-5 Ohm, so measurement voltage must be
  * in 10^-11 Volts for get current in uA.
  * 16 bit current reg fullscale +/-51.2mV is 102400 uV.
  * So: 102400 / 65535 * 10^5 = 156252
  */
 static inline int max172xx_current_to_voltage(unsigned int reg)
 {
 	int val = (int16_t)(reg);

 	return val * 156252;
 }


 static inline struct max17211_device_info *
 to_device_info(struct power_supply *psy)
 {
 	return power_supply_get_drvdata(psy);
 }

 static int max1721x_battery_get_property(struct power_supply *psy,
 	enum power_supply_property psp,
 	union power_supply_propval *val)
 {
 	struct max17211_device_info *info = to_device_info(psy);
 	unsigned int reg = 0;
 	int ret = 0;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_PRESENT:
 		/*
 		 * POWER_SUPPLY_PROP_PRESENT will always readable via
 		 * sysfs interface. Value return 0 if battery not
 		 * present or unaccessible via W1.
 		 */
 		val->intval =
 			regmap_read(info->regmap, MAX172XX_REG_STATUS,
 			&reg) ? 0 : !(reg & MAX172XX_BAT_PRESENT);
 		break;
 	case POWER_SUPPLY_PROP_CAPACITY:
 		ret = regmap_read(info->regmap, MAX172XX_REG_REPSOC, &reg);
 		val->intval = max172xx_percent_to_ps(reg);
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		ret = regmap_read(info->regmap, MAX172XX_REG_BATT, &reg);
 		val->intval = max172xx_voltage_to_ps(reg);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 		ret = regmap_read(info->regmap, MAX172XX_REG_DESIGNCAP, &reg);
 		val->intval = max172xx_capacity_to_ps(reg);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_AVG:
 		ret = regmap_read(info->regmap, MAX172XX_REG_REPCAP, &reg);
 		val->intval = max172xx_capacity_to_ps(reg);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 		ret = regmap_read(info->regmap, MAX172XX_REG_TTE, &reg);
 		val->intval = max172xx_time_to_ps(reg);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 		ret = regmap_read(info->regmap, MAX172XX_REG_TTF, &reg);
 		val->intval = max172xx_time_to_ps(reg);
 		break;
 	case POWER_SUPPLY_PROP_TEMP:
 		ret = regmap_read(info->regmap, MAX172XX_REG_TEMP, &reg);
 		val->intval = max172xx_temperature_to_ps(reg);
 		break;
 	/* We need signed current, so must cast info->rsense to signed type */
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		ret = regmap_read(info->regmap, MAX172XX_REG_CURRENT, &reg);
 		val->intval =
 			max172xx_current_to_voltage(reg) / (int)info->rsense;
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_AVG:
 		ret = regmap_read(info->regmap, MAX172XX_REG_AVGCURRENT, &reg);
 		val->intval =
 			max172xx_current_to_voltage(reg) / (int)info->rsense;
 		break;
 	/*
 	 * Strings already received and inited by probe.
 	 * We do dummy read for check battery still available.
 	 */
 	case POWER_SUPPLY_PROP_MODEL_NAME:
 		ret = regmap_read(info->regmap, MAX1721X_REG_DEV_STR, &reg);
 		val->strval = info->DeviceName;
 		break;
 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		ret = regmap_read(info->regmap, MAX1721X_REG_MFG_STR, &reg);
 		val->strval = info->ManufacturerName;
 		break;
 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 		ret = regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &reg);
 		val->strval = info->SerialNumber;
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static enum power_supply_property max1721x_battery_props[] = {
 	/* int */
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CHARGE_AVG,
 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_CURRENT_AVG,
 	/* strings */
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 };

 static int get_string(struct max17211_device_info *info,
 			uint16_t reg, uint8_t nr, char *str)
 {
 	unsigned int val;

 	if (!str || !(reg == MAX1721X_REG_MFG_STR ||
 			reg == MAX1721X_REG_DEV_STR))
 		return -EFAULT;

 	while (nr--) {
 		if (regmap_read(info->regmap, reg++, &val))
 			return -EFAULT;
 		*str++ = val>>8 & 0x00FF;
 		*str++ = val & 0x00FF;
 	}
 	return 0;
 }

 /* Maxim say: Serial number is a hex string up to 12 hex characters */
 static int get_sn_string(struct max17211_device_info *info, char *str)
 {
 	unsigned int val[3];

 	if (!str)
 		return -EFAULT;

 	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &val[0]))
 		return -EFAULT;
 	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 1, &val[1]))
 		return -EFAULT;
 	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 2, &val[2]))
 		return -EFAULT;

 	snprintf(str, 13, "%04X%04X%04X", val[0], val[1], val[2]);
 	return 0;
 }

 /*
  * MAX1721x registers description for w1-regmap
  */
 static const struct regmap_range max1721x_allow_range[] = {
 	regmap_reg_range(0, 0xDF),	/* volatile data */
 	regmap_reg_range(0x180, 0x1DF),	/* non-volatile memory */
 	regmap_reg_range(0x1E0, 0x1EF),	/* non-volatile history (unused) */
 };

 static const struct regmap_range max1721x_deny_range[] = {
 	/* volatile data unused registers */
 	regmap_reg_range(0x24, 0x26),
 	regmap_reg_range(0x30, 0x31),
 	regmap_reg_range(0x33, 0x34),
 	regmap_reg_range(0x37, 0x37),
 	regmap_reg_range(0x3B, 0x3C),
 	regmap_reg_range(0x40, 0x41),
 	regmap_reg_range(0x43, 0x44),
 	regmap_reg_range(0x47, 0x49),
 	regmap_reg_range(0x4B, 0x4C),
 	regmap_reg_range(0x4E, 0xAF),
 	regmap_reg_range(0xB1, 0xB3),
 	regmap_reg_range(0xB5, 0xB7),
 	regmap_reg_range(0xBF, 0xD0),
 	regmap_reg_range(0xDB, 0xDB),
 	/* hole between volatile and non-volatile registers */
 	regmap_reg_range(0xE0, 0x17F),
 };

 static const struct regmap_access_table max1721x_regs = {
 	.yes_ranges	= max1721x_allow_range,
 	.n_yes_ranges	= ARRAY_SIZE(max1721x_allow_range),
 	.no_ranges	= max1721x_deny_range,
 	.n_no_ranges	= ARRAY_SIZE(max1721x_deny_range),
 };

 /*
  * Model Gauge M5 Algorithm output register
  * Volatile data (must not be cached)
  */
 static const struct regmap_range max1721x_volatile_allow[] = {
 	regmap_reg_range(0, 0xDF),
 };

 static const struct regmap_access_table max1721x_volatile_regs = {
 	.yes_ranges	= max1721x_volatile_allow,
 	.n_yes_ranges	= ARRAY_SIZE(max1721x_volatile_allow),
 };

 /*
  * W1-regmap config
  */
 static const struct regmap_config max1721x_regmap_w1_config = {
 	.reg_bits = 16,
 	.val_bits = 16,
 	.rd_table = &max1721x_regs,
 	.volatile_table = &max1721x_volatile_regs,
 	.max_register = MAX1721X_MAX_REG_NR,
 };

 static int devm_w1_max1721x_add_device(struct w1_slave *sl)
 {
 	struct power_supply_config psy_cfg = {};
 	struct max17211_device_info *info;

 	info = devm_kzalloc(&sl->dev, sizeof(*info), GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;

 	sl->family_data = (void *)info;
 	info->w1_dev = &sl->dev;

 	/*
 	 * power_supply class battery name translated from W1 slave device
 	 * unique ID (look like 26-0123456789AB) to "max1721x-0123456789AB\0"
 	 * so, 26 (device family) correspond to max1721x devices.
 	 * Device name still unique for any number of connected devices.
 	 */
 	snprintf(info->name, sizeof(info->name),
 		"max1721x-%012X", (unsigned int)sl->reg_num.id);
 	info->bat_desc.name = info->name;

 	/*
 	 * FixMe: battery device name exceed max len for thermal_zone device
 	 * name and translation to thermal_zone must be disabled.
 	 */
 	info->bat_desc.no_thermal = true;
 	info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 	info->bat_desc.properties = max1721x_battery_props;
 	info->bat_desc.num_properties = ARRAY_SIZE(max1721x_battery_props);
 	info->bat_desc.get_property = max1721x_battery_get_property;
 	psy_cfg.drv_data = info;

 	/* regmap init */
 	info->regmap = devm_regmap_init_w1(info->w1_dev,
 					&max1721x_regmap_w1_config);
 	if (IS_ERR(info->regmap)) {
 		int err = PTR_ERR(info->regmap);

 		dev_err(info->w1_dev, "Failed to allocate register map: %d\n",
 			err);
 		return err;
 	}

 	/* rsense init */
 	info->rsense = 0;
 	if (regmap_read(info->regmap, MAX1721X_REG_NRSENSE, &info->rsense)) {
 		dev_err(info->w1_dev, "Can't read RSense. Hardware error.\n");
 		return -ENODEV;
 	}

 	if (!info->rsense) {
 		dev_warn(info->w1_dev, "RSense not calibrated, set 10 mOhms!\n");
 		info->rsense = 1000; /* in regs in 10^-5 */
 	}
 	dev_info(info->w1_dev, "RSense: %d mOhms.\n", info->rsense / 100);

 	if (get_string(info, MAX1721X_REG_MFG_STR,
 			MAX1721X_REG_MFG_NUMB, info->ManufacturerName)) {
 		dev_err(info->w1_dev, "Can't read manufacturer. Hardware error.\n");
 		return -ENODEV;
 	}

 	if (!info->ManufacturerName[0])
 		strncpy(info->ManufacturerName, DEF_MFG_NAME,
 			2 * MAX1721X_REG_MFG_NUMB);

 	if (get_string(info, MAX1721X_REG_DEV_STR,
 			MAX1721X_REG_DEV_NUMB, info->DeviceName)) {
 		dev_err(info->w1_dev, "Can't read device. Hardware error.\n");
 		return -ENODEV;
 	}
 	if (!info->DeviceName[0]) {
 		unsigned int dev_name;

 		if (regmap_read(info->regmap,
 				MAX172XX_REG_DEVNAME, &dev_name)) {
 			dev_err(info->w1_dev, "Can't read device name reg.\n");
 			return -ENODEV;
 		}

 		switch (dev_name & MAX172XX_DEV_MASK) {
 		case MAX172X1_DEV:
 			strncpy(info->DeviceName, DEF_DEV_NAME_MAX17211,
 				2 * MAX1721X_REG_DEV_NUMB);
 			break;
 		case MAX172X5_DEV:
 			strncpy(info->DeviceName, DEF_DEV_NAME_MAX17215,
 				2 * MAX1721X_REG_DEV_NUMB);
 			break;
 		default:
 			strncpy(info->DeviceName, DEF_DEV_NAME_UNKNOWN,
 				2 * MAX1721X_REG_DEV_NUMB);
 		}
 	}

 	if (get_sn_string(info, info->SerialNumber)) {
 		dev_err(info->w1_dev, "Can't read serial. Hardware error.\n");
 		return -ENODEV;
 	}

 	info->bat = devm_power_supply_register(&sl->dev, &info->bat_desc,
 						&psy_cfg);
 	if (IS_ERR(info->bat)) {
 		dev_err(info->w1_dev, "failed to register battery\n");
 		return PTR_ERR(info->bat);
 	}

 	return 0;
 }

 static const struct w1_family_ops w1_max1721x_fops = {
 	.add_slave = devm_w1_max1721x_add_device,
 };

 static struct w1_family w1_max1721x_family = {
 	.fid = W1_MAX1721X_FAMILY_ID,
 	.fops = &w1_max1721x_fops,
 };

 module_w1_family(w1_max1721x_family);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>");
 MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauge IC driver");
 MODULE_ALIAS("w1-family-" __stringify(W1_MAX1721X_FAMILY_ID));
	/*
	* 1-Wire implementation for Maxim Semiconductor
	* MAX7211/MAX17215 standalone fuel gauge chip
	*
	* Copyright (C) 2017 Radioavionica Corporation
	* Author: Alex A. Mihaylov <minimumlaw@rambler.ru>
	*
	* Use consistent with the GNU GPL is permitted,
	* provided that this copyright notice is
	* preserved in its entirety in all copies and derived works.
	*
	*/

	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/w1.h>
	#include <linux/regmap.h>
	#include <linux/power_supply.h>

	#define W1_MAX1721X_FAMILY_ID 0x26
	#define DEF_DEV_NAME_MAX17211 "MAX17211"
	#define DEF_DEV_NAME_MAX17215 "MAX17215"
	#define DEF_DEV_NAME_UNKNOWN "UNKNOWN"
	#define DEF_MFG_NAME "MAXIM"

	#define PSY_MAX_NAME_LEN 32

	/* Number of valid register addresses in W1 mode */
	#define MAX1721X_MAX_REG_NR 0x1EF

	/* Factory settings (nonvolatile registers) (W1 specific) */
	#define MAX1721X_REG_NRSENSE 0x1CF /* RSense in 10^-5 Ohm */
	/* Strings */
	#define MAX1721X_REG_MFG_STR 0x1CC
	#define MAX1721X_REG_MFG_NUMB 3
	#define MAX1721X_REG_DEV_STR 0x1DB
	#define MAX1721X_REG_DEV_NUMB 5
	/* HEX Strings */
	#define MAX1721X_REG_SER_HEX 0x1D8

	/* MAX172XX Output Registers for W1 chips */
	#define MAX172XX_REG_STATUS 0x000 /* status reg */
	#define MAX172XX_BAT_PRESENT (1<<4) /* battery connected bit */
	#define MAX172XX_REG_DEVNAME 0x021 /* chip config */
	#define MAX172XX_DEV_MASK 0x000F /* chip type mask */
	#define MAX172X1_DEV 0x0001
	#define MAX172X5_DEV 0x0005
	#define MAX172XX_REG_TEMP 0x008 /* Temperature */
	#define MAX172XX_REG_BATT 0x0DA /* Battery voltage */
	#define MAX172XX_REG_CURRENT 0x00A /* Actual current */
	#define MAX172XX_REG_AVGCURRENT 0x00B /* Average current */
	#define MAX172XX_REG_REPSOC 0x006 /* Percentage of charge */
	#define MAX172XX_REG_DESIGNCAP 0x018 /* Design capacity */
	#define MAX172XX_REG_REPCAP 0x005 /* Average capacity */
	#define MAX172XX_REG_TTE 0x011 /* Time to empty */
	#define MAX172XX_REG_TTF 0x020 /* Time to full */

	struct max17211_device_info {
	char name[PSY_MAX_NAME_LEN];
	struct power_supply *bat;
	struct power_supply_desc bat_desc;
	struct device *w1_dev;
	struct regmap *regmap;
	/* battery design format */
	unsigned int rsense; /* in tenths uOhm */
	char DeviceName[2 * MAX1721X_REG_DEV_NUMB + 1];
	char ManufacturerName[2 * MAX1721X_REG_MFG_NUMB + 1];
	char SerialNumber[13]; /* see get_sn_str() later for comment */
	};

	/* Convert regs value to power_supply units */

	static inline int max172xx_time_to_ps(unsigned int reg)
	{
	return reg * 5625 / 1000; /* in sec. */
	}

	static inline int max172xx_percent_to_ps(unsigned int reg)
	{
	return reg / 256; /* in percent from 0 to 100 */
	}

	static inline int max172xx_voltage_to_ps(unsigned int reg)
	{
	return reg * 1250; /* in uV */
	}

	static inline int max172xx_capacity_to_ps(unsigned int reg)
	{
	return reg * 500; /* in uAh */
	}

	/*
	* Current and temperature is signed values, so unsigned regs
	* value must be converted to signed type
	*/

	static inline int max172xx_temperature_to_ps(unsigned int reg)
	{
	int val = (int16_t)(reg);

	return val * 10 / 256; /* in tenths of deg. C */
	}

	/*
	* Calculating current registers resolution:
	*
	* RSense stored in 10^-5 Ohm, so measurement voltage must be
	* in 10^-11 Volts for get current in uA.
	* 16 bit current reg fullscale +/-51.2mV is 102400 uV.
	* So: 102400 / 65535 * 10^5 = 156252
	*/
	static inline int max172xx_current_to_voltage(unsigned int reg)
	{
	int val = (int16_t)(reg);

	return val * 156252;
	}


	static inline struct max17211_device_info *
	to_device_info(struct power_supply *psy)
	{
	return power_supply_get_drvdata(psy);
	}

	static int max1721x_battery_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct max17211_device_info *info = to_device_info(psy);
	unsigned int reg = 0;
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_PRESENT:
	/*
	* POWER_SUPPLY_PROP_PRESENT will always readable via
	* sysfs interface. Value return 0 if battery not
	* present or unaccessible via W1.
	*/
	val->intval =
	regmap_read(info->regmap, MAX172XX_REG_STATUS,
	&reg) ? 0 : !(reg & MAX172XX_BAT_PRESENT);
	break;
	case POWER_SUPPLY_PROP_CAPACITY:
	ret = regmap_read(info->regmap, MAX172XX_REG_REPSOC, &reg);
	val->intval = max172xx_percent_to_ps(reg);
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	ret = regmap_read(info->regmap, MAX172XX_REG_BATT, &reg);
	val->intval = max172xx_voltage_to_ps(reg);
	break;
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
	ret = regmap_read(info->regmap, MAX172XX_REG_DESIGNCAP, &reg);
	val->intval = max172xx_capacity_to_ps(reg);
	break;
	case POWER_SUPPLY_PROP_CHARGE_AVG:
	ret = regmap_read(info->regmap, MAX172XX_REG_REPCAP, &reg);
	val->intval = max172xx_capacity_to_ps(reg);
	break;
	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
	ret = regmap_read(info->regmap, MAX172XX_REG_TTE, &reg);
	val->intval = max172xx_time_to_ps(reg);
	break;
	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
	ret = regmap_read(info->regmap, MAX172XX_REG_TTF, &reg);
	val->intval = max172xx_time_to_ps(reg);
	break;
	case POWER_SUPPLY_PROP_TEMP:
	ret = regmap_read(info->regmap, MAX172XX_REG_TEMP, &reg);
	val->intval = max172xx_temperature_to_ps(reg);
	break;
	/* We need signed current, so must cast info->rsense to signed type */
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	ret = regmap_read(info->regmap, MAX172XX_REG_CURRENT, &reg);
	val->intval =
	max172xx_current_to_voltage(reg) / (int)info->rsense;
	break;
	case POWER_SUPPLY_PROP_CURRENT_AVG:
	ret = regmap_read(info->regmap, MAX172XX_REG_AVGCURRENT, &reg);
	val->intval =
	max172xx_current_to_voltage(reg) / (int)info->rsense;
	break;
	/*
	* Strings already received and inited by probe.
	* We do dummy read for check battery still available.
	*/
	case POWER_SUPPLY_PROP_MODEL_NAME:
	ret = regmap_read(info->regmap, MAX1721X_REG_DEV_STR, &reg);
	val->strval = info->DeviceName;
	break;
	case POWER_SUPPLY_PROP_MANUFACTURER:
	ret = regmap_read(info->regmap, MAX1721X_REG_MFG_STR, &reg);
	val->strval = info->ManufacturerName;
	break;
	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
	ret = regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &reg);
	val->strval = info->SerialNumber;
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static enum power_supply_property max1721x_battery_props[] = {
	/* int */
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
	POWER_SUPPLY_PROP_CHARGE_AVG,
	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CURRENT_AVG,
	/* strings */
	POWER_SUPPLY_PROP_MODEL_NAME,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	};

	static int get_string(struct max17211_device_info *info,
	uint16_t reg, uint8_t nr, char *str)
	{
	unsigned int val;

	if (!str \|\| !(reg == MAX1721X_REG_MFG_STR \|\|
	reg == MAX1721X_REG_DEV_STR))
	return -EFAULT;

	while (nr--) {
	if (regmap_read(info->regmap, reg++, &val))
	return -EFAULT;
	*str++ = val>>8 & 0x00FF;
	*str++ = val & 0x00FF;
	}
	return 0;
	}

	/* Maxim say: Serial number is a hex string up to 12 hex characters */
	static int get_sn_string(struct max17211_device_info info, char str)
	{
	unsigned int val[3];

	if (!str)
	return -EFAULT;

	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &val[0]))
	return -EFAULT;
	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 1, &val[1]))
	return -EFAULT;
	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 2, &val[2]))
	return -EFAULT;

	snprintf(str, 13, "%04X%04X%04X", val[0], val[1], val[2]);
	return 0;
	}

	/*
	* MAX1721x registers description for w1-regmap
	*/
	static const struct regmap_range max1721x_allow_range[] = {
	regmap_reg_range(0, 0xDF), /* volatile data */
	regmap_reg_range(0x180, 0x1DF), /* non-volatile memory */
	regmap_reg_range(0x1E0, 0x1EF), /* non-volatile history (unused) */
	};

	static const struct regmap_range max1721x_deny_range[] = {
	/* volatile data unused registers */
	regmap_reg_range(0x24, 0x26),
	regmap_reg_range(0x30, 0x31),
	regmap_reg_range(0x33, 0x34),
	regmap_reg_range(0x37, 0x37),
	regmap_reg_range(0x3B, 0x3C),
	regmap_reg_range(0x40, 0x41),
	regmap_reg_range(0x43, 0x44),
	regmap_reg_range(0x47, 0x49),
	regmap_reg_range(0x4B, 0x4C),
	regmap_reg_range(0x4E, 0xAF),
	regmap_reg_range(0xB1, 0xB3),
	regmap_reg_range(0xB5, 0xB7),
	regmap_reg_range(0xBF, 0xD0),
	regmap_reg_range(0xDB, 0xDB),
	/* hole between volatile and non-volatile registers */
	regmap_reg_range(0xE0, 0x17F),
	};

	static const struct regmap_access_table max1721x_regs = {
	.yes_ranges = max1721x_allow_range,
	.n_yes_ranges = ARRAY_SIZE(max1721x_allow_range),
	.no_ranges = max1721x_deny_range,
	.n_no_ranges = ARRAY_SIZE(max1721x_deny_range),
	};

	/*
	* Model Gauge M5 Algorithm output register
	* Volatile data (must not be cached)
	*/
	static const struct regmap_range max1721x_volatile_allow[] = {
	regmap_reg_range(0, 0xDF),
	};

	static const struct regmap_access_table max1721x_volatile_regs = {
	.yes_ranges = max1721x_volatile_allow,
	.n_yes_ranges = ARRAY_SIZE(max1721x_volatile_allow),
	};

	/*
	* W1-regmap config
	*/
	static const struct regmap_config max1721x_regmap_w1_config = {
	.reg_bits = 16,
	.val_bits = 16,
	.rd_table = &max1721x_regs,
	.volatile_table = &max1721x_volatile_regs,
	.max_register = MAX1721X_MAX_REG_NR,
	};

	static int devm_w1_max1721x_add_device(struct w1_slave *sl)
	{
	struct power_supply_config psy_cfg = {};
	struct max17211_device_info *info;

	info = devm_kzalloc(&sl->dev, sizeof(*info), GFP_KERNEL);
	if (!info)
	return -ENOMEM;

	sl->family_data = (void *)info;
	info->w1_dev = &sl->dev;

	/*
	* power_supply class battery name translated from W1 slave device
	* unique ID (look like 26-0123456789AB) to "max1721x-0123456789AB\0"
	* so, 26 (device family) correspond to max1721x devices.
	* Device name still unique for any number of connected devices.
	*/
	snprintf(info->name, sizeof(info->name),
	"max1721x-%012X", (unsigned int)sl->reg_num.id);
	info->bat_desc.name = info->name;

	/*
	* FixMe: battery device name exceed max len for thermal_zone device
	* name and translation to thermal_zone must be disabled.
	*/
	info->bat_desc.no_thermal = true;
	info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
	info->bat_desc.properties = max1721x_battery_props;
	info->bat_desc.num_properties = ARRAY_SIZE(max1721x_battery_props);
	info->bat_desc.get_property = max1721x_battery_get_property;
	psy_cfg.drv_data = info;

	/* regmap init */
	info->regmap = devm_regmap_init_w1(info->w1_dev,
	&max1721x_regmap_w1_config);
	if (IS_ERR(info->regmap)) {
	int err = PTR_ERR(info->regmap);

	dev_err(info->w1_dev, "Failed to allocate register map: %d\n",
	err);
	return err;
	}

	/* rsense init */
	info->rsense = 0;
	if (regmap_read(info->regmap, MAX1721X_REG_NRSENSE, &info->rsense)) {
	dev_err(info->w1_dev, "Can't read RSense. Hardware error.\n");
	return -ENODEV;
	}

	if (!info->rsense) {
	dev_warn(info->w1_dev, "RSense not calibrated, set 10 mOhms!\n");
	info->rsense = 1000; /* in regs in 10^-5 */
	}
	dev_info(info->w1_dev, "RSense: %d mOhms.\n", info->rsense / 100);

	if (get_string(info, MAX1721X_REG_MFG_STR,
	MAX1721X_REG_MFG_NUMB, info->ManufacturerName)) {
	dev_err(info->w1_dev, "Can't read manufacturer. Hardware error.\n");
	return -ENODEV;
	}

	if (!info->ManufacturerName[0])
	strncpy(info->ManufacturerName, DEF_MFG_NAME,
	2 * MAX1721X_REG_MFG_NUMB);

	if (get_string(info, MAX1721X_REG_DEV_STR,
	MAX1721X_REG_DEV_NUMB, info->DeviceName)) {
	dev_err(info->w1_dev, "Can't read device. Hardware error.\n");
	return -ENODEV;
	}
	if (!info->DeviceName[0]) {
	unsigned int dev_name;

	if (regmap_read(info->regmap,
	MAX172XX_REG_DEVNAME, &dev_name)) {
	dev_err(info->w1_dev, "Can't read device name reg.\n");
	return -ENODEV;
	}

	switch (dev_name & MAX172XX_DEV_MASK) {
	case MAX172X1_DEV:
	strncpy(info->DeviceName, DEF_DEV_NAME_MAX17211,
	2 * MAX1721X_REG_DEV_NUMB);
	break;
	case MAX172X5_DEV:
	strncpy(info->DeviceName, DEF_DEV_NAME_MAX17215,
	2 * MAX1721X_REG_DEV_NUMB);
	break;
	default:
	strncpy(info->DeviceName, DEF_DEV_NAME_UNKNOWN,
	2 * MAX1721X_REG_DEV_NUMB);
	}
	}

	if (get_sn_string(info, info->SerialNumber)) {
	dev_err(info->w1_dev, "Can't read serial. Hardware error.\n");
	return -ENODEV;
	}

	info->bat = devm_power_supply_register(&sl->dev, &info->bat_desc,
	&psy_cfg);
	if (IS_ERR(info->bat)) {
	dev_err(info->w1_dev, "failed to register battery\n");
	return PTR_ERR(info->bat);
	}

	return 0;
	}

	static const struct w1_family_ops w1_max1721x_fops = {
	.add_slave = devm_w1_max1721x_add_device,
	};

	static struct w1_family w1_max1721x_family = {
	.fid = W1_MAX1721X_FAMILY_ID,
	.fops = &w1_max1721x_fops,
	};

	module_w1_family(w1_max1721x_family);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>");
	MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauge IC driver");
	MODULE_ALIAS("w1-family-" __stringify(W1_MAX1721X_FAMILY_ID));