Commit 479b6d04 authored by Dimitri Fedrau's avatar Dimitri Fedrau Committed by Sebastian Reichel
Browse files

power: supply: add support for MAX1720x standalone fuel gauge 



The MAX17201 monitors a single cell pack. The MAX17205 monitors and
balances a 2S or 3S pack or monitors a multiple-series cell pack. Both
devices use a I2C interface.

Signed-off-by: default avatarDimitri Fedrau <dima.fedrau@gmail.com>
Link: https://lore.kernel.org/r/20240702090308.8848-3-dima.fedrau@gmail.com


Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent ad0aa236

drivers/power/supply/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -411,6 +411,18 @@ config BATTERY_MAX17042 


	  Driver can be build as a module (max17042_battery).



config BATTERY_MAX1720X

	tristate "Maxim MAX17201/MAX17205 Fuel Gauge"

	depends on I2C

	select REGMAP_I2C

	help

	  MAX1720x is a family of fuel-gauge systems for lithium-ion (Li+)

	  batteries in handheld and portable equipment. MAX17201 are

	  configured to operate with a single lithium cell, the MAX17205

	  can operate with multiple cells.



	  Say Y to include support for the MAX17201/MAX17205 Fuel Gauges.



config BATTERY_MAX1721X

	tristate "MAX17211/MAX17215 standalone gas-gauge"

	depends on W1

drivers/power/supply/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ obj-$(CONFIG_CHARGER_DA9150) += da9150-charger.o 
obj-$(CONFIG_BATTERY_DA9150)	+= da9150-fg.o

obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o

obj-$(CONFIG_BATTERY_MAX17042)	+= max17042_battery.o

obj-$(CONFIG_BATTERY_MAX1720X)	+= max1720x_battery.o

obj-$(CONFIG_BATTERY_MAX1721X)	+= max1721x_battery.o

obj-$(CONFIG_BATTERY_RT5033)	+= rt5033_battery.o

obj-$(CONFIG_CHARGER_RT5033)	+= rt5033_charger.o

drivers/power/supply/max1720x_battery.c

0 → 100644
+337 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * Fuel gauge driver for Maxim 17201/17205

 *

 * based on max1721x_battery.c

 *

 * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH

 */



#include <linux/bitfield.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/power_supply.h>

#include <linux/regmap.h>



#include <asm/unaligned.h>



/* Nonvolatile registers */

#define MAX1720X_NRSENSE		0xCF	/* RSense in 10^-5 Ohm */



/* ModelGauge m5 */

#define MAX172XX_STATUS			0x00	/* Status */

#define MAX172XX_STATUS_BAT_ABSENT	BIT(3)	/* Battery absent */

#define MAX172XX_REPCAP			0x05	/* Average capacity */

#define MAX172XX_REPSOC			0x06	/* Percentage of charge */

#define MAX172XX_TEMP			0x08	/* Temperature */

#define MAX172XX_CURRENT		0x0A	/* Actual current */

#define MAX172XX_AVG_CURRENT		0x0B	/* Average current */

#define MAX172XX_TTE			0x11	/* Time to empty */

#define MAX172XX_AVG_TA			0x16	/* Average temperature */

#define MAX172XX_CYCLES			0x17

#define MAX172XX_DESIGN_CAP		0x18	/* Design capacity */

#define MAX172XX_AVG_VCELL		0x19

#define MAX172XX_TTF			0x20	/* Time to full */

#define MAX172XX_DEV_NAME		0x21	/* Device name */

#define MAX172XX_DEV_NAME_TYPE_MASK	GENMASK(3, 0)

#define MAX172XX_DEV_NAME_TYPE_MAX17201	BIT(0)

#define MAX172XX_DEV_NAME_TYPE_MAX17205	(BIT(0) | BIT(2))

#define MAX172XX_QR_TABLE10		0x22

#define MAX172XX_BATT			0xDA	/* Battery voltage */

#define MAX172XX_ATAVCAP		0xDF



static const char *const max1720x_manufacturer = "Maxim Integrated";

static const char *const max17201_model = "MAX17201";

static const char *const max17205_model = "MAX17205";



struct max1720x_device_info {

	struct regmap *regmap;

	int rsense;

};



/*

 * Model Gauge M5 Algorithm output register

 * Volatile data (must not be cached)

 */

static const struct regmap_range max1720x_volatile_allow[] = {

	regmap_reg_range(MAX172XX_STATUS, MAX172XX_CYCLES),

	regmap_reg_range(MAX172XX_AVG_VCELL, MAX172XX_TTF),

	regmap_reg_range(MAX172XX_QR_TABLE10, MAX172XX_ATAVCAP),

};



static const struct regmap_range max1720x_readable_allow[] = {

	regmap_reg_range(MAX172XX_STATUS, MAX172XX_ATAVCAP),

};



static const struct regmap_range max1720x_readable_deny[] = {

	/* 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),

	regmap_reg_range(0xE0, 0xFF),

};



static const struct regmap_access_table max1720x_readable_regs = {

	.yes_ranges	= max1720x_readable_allow,

	.n_yes_ranges	= ARRAY_SIZE(max1720x_readable_allow),

	.no_ranges	= max1720x_readable_deny,

	.n_no_ranges	= ARRAY_SIZE(max1720x_readable_deny),

};



static const struct regmap_access_table max1720x_volatile_regs = {

	.yes_ranges	= max1720x_volatile_allow,

	.n_yes_ranges	= ARRAY_SIZE(max1720x_volatile_allow),

	.no_ranges	= max1720x_readable_deny,

	.n_no_ranges	= ARRAY_SIZE(max1720x_readable_deny),

};



static const struct regmap_config max1720x_regmap_cfg = {

	.reg_bits = 8,

	.val_bits = 16,

	.max_register = MAX172XX_ATAVCAP,

	.val_format_endian = REGMAP_ENDIAN_LITTLE,

	.rd_table = &max1720x_readable_regs,

	.volatile_table = &max1720x_volatile_regs,

	.cache_type = REGCACHE_RBTREE,

};



static const enum power_supply_property max1720x_battery_props[] = {

	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,

	POWER_SUPPLY_PROP_MODEL_NAME,

	POWER_SUPPLY_PROP_MANUFACTURER,

};



/* Convert regs value to power_supply units */



static int max172xx_time_to_ps(unsigned int reg)

{

	return reg * 5625 / 1000;	/* in sec. */

}



static int max172xx_percent_to_ps(unsigned int reg)

{

	return reg / 256;	/* in percent from 0 to 100 */

}



static int max172xx_voltage_to_ps(unsigned int reg)

{

	return reg * 1250;	/* in uV */

}



static 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 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 mesaurment 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 int max172xx_current_to_voltage(unsigned int reg)

{

	int val = (int16_t)reg;



	return val * 156252;

}



static int max1720x_battery_get_property(struct power_supply *psy,

					 enum power_supply_property psp,

					 union power_supply_propval *val)

{

	struct max1720x_device_info *info = power_supply_get_drvdata(psy);

	unsigned int reg_val;

	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 unaccesable via I2c.

		 */

		ret = regmap_read(info->regmap, MAX172XX_STATUS, &reg_val);

		if (ret < 0) {

			val->intval = 0;

			return 0;

		}



		val->intval = !FIELD_GET(MAX172XX_STATUS_BAT_ABSENT, reg_val);

		break;

	case POWER_SUPPLY_PROP_CAPACITY:

		ret = regmap_read(info->regmap, MAX172XX_REPSOC, &reg_val);

		val->intval = max172xx_percent_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_VOLTAGE_NOW:

		ret = regmap_read(info->regmap, MAX172XX_BATT, &reg_val);

		val->intval = max172xx_voltage_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:

		ret = regmap_read(info->regmap, MAX172XX_DESIGN_CAP, &reg_val);

		val->intval = max172xx_capacity_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_CHARGE_AVG:

		ret = regmap_read(info->regmap, MAX172XX_REPCAP, &reg_val);

		val->intval = max172xx_capacity_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:

		ret = regmap_read(info->regmap, MAX172XX_TTE, &reg_val);

		val->intval = max172xx_time_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:

		ret = regmap_read(info->regmap, MAX172XX_TTF, &reg_val);

		val->intval = max172xx_time_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_TEMP:

		ret = regmap_read(info->regmap, MAX172XX_TEMP, &reg_val);

		val->intval = max172xx_temperature_to_ps(reg_val);

		break;

	case POWER_SUPPLY_PROP_CURRENT_NOW:

		ret = regmap_read(info->regmap, MAX172XX_CURRENT, &reg_val);

		val->intval = max172xx_current_to_voltage(reg_val) / info->rsense;

		break;

	case POWER_SUPPLY_PROP_CURRENT_AVG:

		ret = regmap_read(info->regmap, MAX172XX_AVG_CURRENT, &reg_val);

		val->intval = max172xx_current_to_voltage(reg_val) / info->rsense;

		break;

	case POWER_SUPPLY_PROP_MODEL_NAME:

		ret = regmap_read(info->regmap, MAX172XX_DEV_NAME, &reg_val);

		reg_val = FIELD_GET(MAX172XX_DEV_NAME_TYPE_MASK, reg_val);

		if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17201)

			val->strval = max17201_model;

		else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205)

			val->strval = max17205_model;

		else

			return -ENODEV;

		break;

	case POWER_SUPPLY_PROP_MANUFACTURER:

		val->strval = max1720x_manufacturer;

		break;

	default:

		return -EINVAL;

	}



	return ret;

}



static int max1720x_probe_sense_resistor(struct i2c_client *client,

					 struct max1720x_device_info *info)

{

	struct device *dev = &client->dev;

	struct i2c_client *ancillary;

	int ret;



	ancillary = i2c_new_ancillary_device(client, "nvmem", 0xb);

	if (IS_ERR(ancillary)) {

		dev_err(dev, "Failed to initialize ancillary i2c device\n");

		return PTR_ERR(ancillary);

	}



	ret = i2c_smbus_read_word_data(ancillary, MAX1720X_NRSENSE);

	i2c_unregister_device(ancillary);

	if (ret < 0)

		return ret;



	info->rsense = ret;

	if (!info->rsense) {

		dev_warn(dev, "RSense not calibrated, set 10 mOhms!\n");

		info->rsense = 1000; /* in regs in 10^-5 */

	}



	return 0;

}



static const struct power_supply_desc max1720x_bat_desc = {

	.name = "max1720x",

	.no_thermal = true,

	.type = POWER_SUPPLY_TYPE_BATTERY,

	.properties = max1720x_battery_props,

	.num_properties = ARRAY_SIZE(max1720x_battery_props),

	.get_property = max1720x_battery_get_property,

};



static int max1720x_probe(struct i2c_client *client)

{

	struct power_supply_config psy_cfg = {};

	struct device *dev = &client->dev;

	struct max1720x_device_info *info;

	struct power_supply *bat;

	int ret;



	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);

	if (!info)

		return -ENOMEM;



	psy_cfg.drv_data = info;

	psy_cfg.fwnode = dev_fwnode(dev);

	info->regmap = devm_regmap_init_i2c(client, &max1720x_regmap_cfg);

	if (IS_ERR(info->regmap))

		return dev_err_probe(dev, PTR_ERR(info->regmap),

				     "regmap initialization failed\n");



	ret = max1720x_probe_sense_resistor(client, info);

	if (ret)

		return dev_err_probe(dev, ret,

				     "Failed to read sense resistor value\n");



	bat = devm_power_supply_register(dev, &max1720x_bat_desc, &psy_cfg);

	if (IS_ERR(bat))

		return dev_err_probe(dev, PTR_ERR(bat),

				     "Failed to register power supply\n");



	return 0;

}



static const struct of_device_id max1720x_of_match[] = {

	{ .compatible = "maxim,max17201" },

	{}

};

MODULE_DEVICE_TABLE(of, max1720x_of_match);



static struct i2c_driver max1720x_i2c_driver = {

	.driver = {

		.name = "max1720x",

		.of_match_table = max1720x_of_match,

	},

	.probe = max1720x_probe,

};

module_i2c_driver(max1720x_i2c_driver);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Dimitri Fedrau <dima.fedrau@gmail.com>");

MODULE_DESCRIPTION("Maxim MAX17201/MAX17205 Fuel Gauge IC driver");