Add driver for Maxim 77705 fuel gauge (part of max77705 PMIC) providing power supply class information to userspace. The driver is configured through DTS (battery and system related settings). Signed-off-by: Dzmitry Sankouski <dsankouski@xxxxxxxxx> --- Changes for v8: - join line where possible to fit in 100 chars - change comment style C++ -> C - fix kernel-doc comments Changes for v6: - add i2c init in driver - initialize unintialized ret value with 0 - remove unused CAPACITY_SCALE_* constants - max77705_*_convert: replace multiplication and divison with mult_frac helper to fix https://lore.kernel.org/oe-kbuild-all/202410111913.5ADtNHNM-lkp@xxxxxxxxx/ - max77705_battery_settings: move out battery settings gathering and rename function - probe: do regmap setup last, because if power_supply_get_battery_info fails, we're going to probe again and fail with i2c bus busy error - remove MFD from commit message Changes for v5: - fix license - use same hardware name in Kconfig and module descriptions - fix email, and module author Changes for v4: - rework driver from scratch - change word delimiters in filenames to "_" - remove debugfs code - cleanup header --- drivers/power/supply/Kconfig | 7 +++ drivers/power/supply/Makefile | 1 + drivers/power/supply/max77705_fuel_gauge.c | 363 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/power/max77705_fuelgauge.h | 71 +++++++++++++++++++++++++++ 4 files changed, 442 insertions(+) diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig index 66264036b65d..9a3b17036ddc 100644 --- a/drivers/power/supply/Kconfig +++ b/drivers/power/supply/Kconfig @@ -589,6 +589,13 @@ config CHARGER_MAX77705 help Say Y to enable support for the Maxim MAX77705 battery charger. +config FUEL_GAUGE_MAX77705 + tristate "Maxim MAX77705 fuel gauge driver" + depends on MFD_MAX77705 + default n + help + Say Y to enable support for MAXIM MAX77705 fuel gauge driver. + config CHARGER_MAX77976 tristate "Maxim MAX77976 battery charger driver" depends on I2C diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile index 85d65b7aee1c..997049fc1795 100644 --- a/drivers/power/supply/Makefile +++ b/drivers/power/supply/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_CHARGER_DETECTOR_MAX14656) += max14656_charger_detector.o obj-$(CONFIG_CHARGER_MAX77650) += max77650-charger.o obj-$(CONFIG_CHARGER_MAX77693) += max77693_charger.o obj-$(CONFIG_CHARGER_MAX77705) += max77705_charger.o +obj-$(CONFIG_FUEL_GAUGE_MAX77705) += max77705_fuel_gauge.o obj-$(CONFIG_CHARGER_MAX77976) += max77976_charger.o obj-$(CONFIG_CHARGER_MAX8997) += max8997_charger.o obj-$(CONFIG_CHARGER_MAX8998) += max8998_charger.o diff --git a/drivers/power/supply/max77705_fuel_gauge.c b/drivers/power/supply/max77705_fuel_gauge.c new file mode 100644 index 000000000000..43feeb77b47a --- /dev/null +++ b/drivers/power/supply/max77705_fuel_gauge.c @@ -0,0 +1,363 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2024 Dzmitry Sankouski <dsankouski@gmail> + * + * Fuel gauge driver for MAXIM 77705 charger/power-supply. + */ + +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/mfd/max77693-common.h> +#include <linux/mfd/max77705-private.h> +#include <linux/power/max77705_fuelgauge.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/power_supply.h> +#include <linux/regmap.h> + +#define I2C_ADDR_FG 0x36 + +static const char *max77705_fuelgauge_model = "max77705"; +static const char *max77705_fuelgauge_manufacturer = "Maxim Integrated"; + +static const struct regmap_config max77705_fg_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = MAX77705_FG_END, +}; + +static enum power_supply_property max77705_fuelgauge_props[] = { + POWER_SUPPLY_PROP_STATUS, + POWER_SUPPLY_PROP_PRESENT, + POWER_SUPPLY_PROP_VOLTAGE_NOW, + POWER_SUPPLY_PROP_VOLTAGE_OCV, + POWER_SUPPLY_PROP_VOLTAGE_AVG, + POWER_SUPPLY_PROP_CURRENT_NOW, + POWER_SUPPLY_PROP_CURRENT_AVG, + POWER_SUPPLY_PROP_CHARGE_NOW, + POWER_SUPPLY_PROP_CHARGE_FULL, + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, + POWER_SUPPLY_PROP_CAPACITY, + POWER_SUPPLY_PROP_TEMP, + POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW, + POWER_SUPPLY_PROP_TIME_TO_FULL_NOW, +}; + +static int max77705_fg_read_reg(struct max77705_fuelgauge_data *fuelgauge, + unsigned int reg, unsigned int *val) +{ + struct regmap *regmap = fuelgauge->regmap; + u8 data[2]; + int ret; + + ret = regmap_noinc_read(regmap, reg, data, sizeof(data)); + if (ret < 0) + return ret; + + *val = (data[1] << 8) + data[0]; + + return 0; +} + +static int max77705_fg_read_temp(struct max77705_fuelgauge_data *fuelgauge, + int *val) +{ + struct regmap *regmap = fuelgauge->regmap; + u8 data[2] = { 0, 0 }; + int ret, temperature = 0; + + ret = regmap_noinc_read(regmap, TEMPERATURE_REG, data, sizeof(data)); + if (ret < 0) + return ret; + + if (data[1] & BIT(7)) + temperature = ((~(data[1])) & 0xFF) + 1; + else + temperature = data[1] & 0x7f; + + temperature *= 10; + temperature += data[0] * 10 / 256; + *val = temperature; + + return 0; +} + +static int max77705_fg_check_battery_present(struct max77705_fuelgauge_data + *fuelgauge, int *val) +{ + struct regmap *regmap = fuelgauge->regmap; + u8 status_data[2]; + int ret; + + ret = regmap_noinc_read(regmap, STATUS_REG, status_data, sizeof(status_data)); + if (ret < 0) + return ret; + + *val = !(status_data[0] & MAX77705_BAT_ABSENT_MASK); + + return 0; +} + +static int max77705_battery_get_status(struct max77705_fuelgauge_data *fuelgauge, + int *val) +{ + int current_now; + int am_i_supplied; + int ret; + unsigned int soc_rep; + + am_i_supplied = power_supply_am_i_supplied(fuelgauge->psy_fg); + if (am_i_supplied) { + if (am_i_supplied == -ENODEV) { + dev_err(fuelgauge->dev, + "power supply not found, fall back to current-based method\n"); + } else { + *val = POWER_SUPPLY_STATUS_CHARGING; + return 0; + } + } + ret = max77705_fg_read_reg(fuelgauge, SOCREP_REG, &soc_rep); + if (ret) + return ret; + + if (soc_rep < 100) { + ret = max77705_fg_read_reg(fuelgauge, CURRENT_REG, ¤t_now); + if (ret) + return ret; + + if (current_now > 0) + *val = POWER_SUPPLY_STATUS_CHARGING; + else if (current_now < 0) + *val = POWER_SUPPLY_STATUS_DISCHARGING; + else + *val = POWER_SUPPLY_STATUS_NOT_CHARGING; + } else { + *val = POWER_SUPPLY_STATUS_FULL; + } + + return 0; +} + +static void max77705_unit_adjustment(struct max77705_fuelgauge_data *fuelgauge, + enum power_supply_property psp, + union power_supply_propval *val) +{ + const unsigned int base_unit_conversion = 1000; + + switch (psp) { + case POWER_SUPPLY_PROP_VOLTAGE_NOW: + case POWER_SUPPLY_PROP_VOLTAGE_OCV: + case POWER_SUPPLY_PROP_VOLTAGE_AVG: + val->intval = max77705_fg_vs_convert(val->intval); + break; + case POWER_SUPPLY_PROP_CURRENT_NOW: + case POWER_SUPPLY_PROP_CURRENT_AVG: + val->intval = max77705_fg_cs_convert(val->intval, + fuelgauge->rsense_conductance); + break; + case POWER_SUPPLY_PROP_CHARGE_NOW: + case POWER_SUPPLY_PROP_CHARGE_FULL: + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: + val->intval *= base_unit_conversion; + break; + case POWER_SUPPLY_PROP_CAPACITY: + val->intval = min(val->intval, 100); + break; + default: + dev_dbg(fuelgauge->dev, + "%s: no need for unit conversion %d\n", __func__, psp); + } +} + +static int max77705_fg_get_property(struct power_supply *psy, + enum power_supply_property psp, + union power_supply_propval *val) +{ + struct max77705_fuelgauge_data *fuelgauge = + power_supply_get_drvdata(psy); + int ret = 0; + + switch (psp) { + case POWER_SUPPLY_PROP_STATUS: + ret = max77705_battery_get_status(fuelgauge, &val->intval); + break; + case POWER_SUPPLY_PROP_PRESENT: + ret = max77705_fg_check_battery_present(fuelgauge, &val->intval); + break; + case POWER_SUPPLY_PROP_VOLTAGE_NOW: + ret = max77705_fg_read_reg(fuelgauge, VCELL_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_VOLTAGE_OCV: + ret = max77705_fg_read_reg(fuelgauge, VFOCV_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_VOLTAGE_AVG: + ret = max77705_fg_read_reg(fuelgauge, AVR_VCELL_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CURRENT_NOW: + ret = max77705_fg_read_reg(fuelgauge, CURRENT_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CURRENT_AVG: + ret = max77705_fg_read_reg(fuelgauge, AVG_CURRENT_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CHARGE_NOW: + ret = max77705_fg_read_reg(fuelgauge, REMCAP_REP_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CHARGE_FULL: + ret = max77705_fg_read_reg(fuelgauge, FULLCAP_REP_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: + ret = max77705_fg_read_reg(fuelgauge, DESIGNCAP_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CAPACITY: + ret = max77705_fg_read_reg(fuelgauge, SOCREP_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_TEMP: + ret = max77705_fg_read_temp(fuelgauge, &val->intval); + break; + case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: + ret = max77705_fg_read_reg(fuelgauge, TIME_TO_EMPTY_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW: + ret = max77705_fg_read_reg(fuelgauge, TIME_TO_FULL_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_CYCLE_COUNT: + ret = max77705_fg_read_reg(fuelgauge, CYCLES_REG, &val->intval); + break; + case POWER_SUPPLY_PROP_MODEL_NAME: + val->strval = max77705_fuelgauge_model; + break; + case POWER_SUPPLY_PROP_MANUFACTURER: + val->strval = max77705_fuelgauge_manufacturer; + break; + default: + return -EINVAL; + } + + if (ret) + return ret; + + max77705_unit_adjustment(fuelgauge, psp, val); + + return 0; +} + +static const struct power_supply_desc max77705_fg_desc = { + .name = "max77705-fuel-gauge", + .type = POWER_SUPPLY_TYPE_BATTERY, + .properties = max77705_fuelgauge_props, + .num_properties = ARRAY_SIZE(max77705_fuelgauge_props), + .get_property = max77705_fg_get_property, +}; + +static int max77705_fg_set_charge_design(struct regmap *regmap, int value) +{ + u8 data[2]; + int value_mah; + + value_mah = value / 1000; + data[0] = value_mah & 0xFF; + data[1] = (value_mah >> 8) & 0xFF; + + return regmap_noinc_write(regmap, DESIGNCAP_REG, data, sizeof(data)); +} + +static int max77705_write_bat_info(struct max77705_fuelgauge_data *fuelgauge) +{ + struct power_supply_battery_info *info = fuelgauge->bat_info; + + if (info->energy_full_design_uwh != info->charge_full_design_uah) { + if (info->charge_full_design_uah == -EINVAL) + dev_warn(fuelgauge->dev, "missing battery:charge-full-design-microamp-hours\n"); + return max77705_fg_set_charge_design(fuelgauge->regmap, + info->charge_full_design_uah); + } + + return 0; +} + +static int max77705_fuelgauge_parse_dt(struct max77705_fuelgauge_data + *fuelgauge) +{ + struct device *dev = fuelgauge->dev; + struct device_node *np = dev->of_node; + int ret; + unsigned int rsense; + + if (!np) { + dev_err(dev, "no fuelgauge OF node\n"); + return -EINVAL; + } + ret = of_property_read_u32(np, "shunt-resistor-micro-ohms", + &rsense); + if (ret < 0) { + dev_warn(dev, "No shunt-resistor-micro-ohms property, assume default\n"); + fuelgauge->rsense_conductance = 100; + } else + fuelgauge->rsense_conductance = 1000000 / rsense; /* rsense conductance in Ohm^-1 */ + + return 0; +} + +static int max77705_fuelgauge_probe(struct platform_device *pdev) +{ + struct i2c_client *i2c_fg; + struct max77693_dev *max77705 = dev_get_drvdata(pdev->dev.parent); + struct max77705_fuelgauge_data *fuelgauge; + struct power_supply_config fuelgauge_cfg = { }; + struct device *dev = &pdev->dev; + int ret = 0; + + fuelgauge = devm_kzalloc(dev, sizeof(*fuelgauge), GFP_KERNEL); + if (!fuelgauge) + return -ENOMEM; + + fuelgauge->dev = dev; + + ret = max77705_fuelgauge_parse_dt(fuelgauge); + if (ret < 0) + return ret; + + fuelgauge_cfg.drv_data = fuelgauge; + fuelgauge_cfg.of_node = fuelgauge->dev->of_node; + + fuelgauge->psy_fg = devm_power_supply_register(&pdev->dev, + &max77705_fg_desc, + &fuelgauge_cfg); + + if (IS_ERR(fuelgauge->psy_fg)) + return PTR_ERR(fuelgauge->psy_fg); + + ret = power_supply_get_battery_info(fuelgauge->psy_fg, + &fuelgauge->bat_info); + + if (ret) + return ret; + + i2c_fg = devm_i2c_new_dummy_device(max77705->dev, max77705->i2c->adapter, I2C_ADDR_FG); + + if (IS_ERR(i2c_fg)) + return PTR_ERR(i2c_fg); + + fuelgauge->regmap = devm_regmap_init_i2c(i2c_fg, &max77705_fg_regmap_config); + + return max77705_write_bat_info(fuelgauge); +} + +static const struct of_device_id max77705_fg_of_match[] = { + { .compatible = "maxim,max77705-fuel-gauge" }, + { } +}; +MODULE_DEVICE_TABLE(of, max77705_fg_of_match); + +static struct platform_driver max77705_fuelgauge_driver = { + .driver = { + .name = "max77705-fuel-gauge", + .of_match_table = max77705_fg_of_match, + }, + .probe = max77705_fuelgauge_probe, +}; +module_platform_driver(max77705_fuelgauge_driver); + +MODULE_DESCRIPTION("Maxim MAX77705 Fuel Gauge Driver"); +MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail>"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/power/max77705_fuelgauge.h b/include/linux/power/max77705_fuelgauge.h new file mode 100644 index 000000000000..4c9f0f38f773 --- /dev/null +++ b/include/linux/power/max77705_fuelgauge.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2024 Dzmitry Sankouski <dsankouski@xxxxxxxxx> + * + * Fuel gauge driver header for MAXIM 77705 charger/power-supply. + */ + +#ifndef __MAX77705_FUELGAUGE_H +#define __MAX77705_FUELGAUGE_H __FILE__ + +#include <linux/regmap.h> +#include <linux/platform_device.h> +#include <linux/power_supply.h> + +#define ALERT_EN 4 +/* + * Current and capacity values are displayed as a voltage + * and must be divided by the sense resistor to determine Amps or Amp-hours. + * This should be applied to all current, charge, energy registers, + * except ModelGauge m5 Algorithm related ones. + * current sense resolution + */ +#define MAX77705_FG_CS_ADC_RESOLUTION 15625 /* 1.5625 microvolts */ +/* voltage sense resolution */ +#define MAX77705_FG_VS_ADC_RESOLUTION 78125 /* 78.125 microvolts */ +/* CONFIG_REG register */ +#define MAX77705_SOC_ALERT_EN_MASK BIT(2) +/* When set to 1, external temperature measurements should be written from the host */ +#define MAX77705_TEX_MASK BIT(8) +/* Enable Thermistor */ +#define MAX77705_ETHRM_MASK BIT(5) +/* CONFIG2_REG register */ +#define MAX77705_AUTO_DISCHARGE_EN_MASK BIT(9) +/* STATUS_REG register */ +#define MAX77705_BAT_ABSENT_MASK BIT(3) + +/** + * max77705_fg_vs_convert() - Convert voltage register value to micro volts. + * + * @reg_val: Register value. + * + * Return: Voltage in micro Volts. + */ +inline u64 max77705_fg_vs_convert(u16 reg_val) +{ + return mult_frac(reg_val, MAX77705_FG_VS_ADC_RESOLUTION, 1000); +} + +/** + * max77705_fg_cs_convert() - Convert current register value to micro volts. + * + * @reg_val: Register value. + * @rsense_conductance: Current sense resistor conductance in Ohm^-1. + * + * Return: Current in micro Volts. + */ +inline s32 max77705_fg_cs_convert(s16 reg_val, u32 rsense_conductance) +{ + return mult_frac(reg_val * rsense_conductance, MAX77705_FG_CS_ADC_RESOLUTION, + 10000); +} + +struct max77705_fuelgauge_data { + struct device *dev; + struct regmap *regmap; + struct power_supply *psy_fg; + struct power_supply_battery_info *bat_info; + u32 rsense_conductance; +}; + +#endif /* __MAX77705_FUELGAUGE_H */ -- 2.39.2
