@@ -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
@@ -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
new file mode 100644
@@ -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");
new file mode 100644
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Dzmitry Sankouski <dsankouski@gmail.org>
+ *
+ * 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 */
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@gmail.com> --- 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@intel.com/ - 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(+)