From: André Draszik Date: Mon, 2 Mar 2026 13:32:09 +0000 (+0000) Subject: power: supply: max17042: consider task period (max77759) X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=83a86e27c34d06ec2dc117fb293e80f78402df49;p=thirdparty%2Fkernel%2Flinux.git power: supply: max17042: consider task period (max77759) Several (register) values reported by the fuel gauge depend on its internal task period and it needs to be taken into account when calculating results. All relevant example formulas in the data sheet assume the default task period (of 5760) and final results need to be adjusted based on the task period in effect. Update the code as and where necessary. Reviewed-by: Peter Griffin Signed-off-by: André Draszik Link: https://patch.msgid.link/20260302-max77759-fg-v3-10-3c5f01dbda23@linaro.org Signed-off-by: Sebastian Reichel --- diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c index b9a21cef2cc61..bafbf87060559 100644 --- a/drivers/power/supply/max17042_battery.c +++ b/drivers/power/supply/max17042_battery.c @@ -61,6 +61,7 @@ struct max17042_chip { struct work_struct work; int init_complete; int irq; + int task_period; }; static enum power_supply_property max17042_battery_props[] = { @@ -331,6 +332,8 @@ static int max17042_get_property(struct power_supply *psy, return ret; data64 = data * 5000000ll; + data64 *= chip->task_period; + do_div(data64, MAX17042_DEFAULT_TASK_PERIOD); do_div(data64, chip->pdata->r_sns); val->intval = data64; break; @@ -340,6 +343,8 @@ static int max17042_get_property(struct power_supply *psy, return ret; data64 = data * 5000000ll; + data64 *= chip->task_period; + do_div(data64, MAX17042_DEFAULT_TASK_PERIOD); do_div(data64, chip->pdata->r_sns); val->intval = data64; break; @@ -349,6 +354,8 @@ static int max17042_get_property(struct power_supply *psy, return ret; data64 = data * 5000000ll; + data64 *= chip->task_period; + do_div(data64, MAX17042_DEFAULT_TASK_PERIOD); do_div(data64, chip->pdata->r_sns); val->intval = data64; break; @@ -358,6 +365,8 @@ static int max17042_get_property(struct power_supply *psy, return ret; data64 = sign_extend64(data, 15) * 5000000ll; + data64 *= chip->task_period; + data64 = div_s64(data64, MAX17042_DEFAULT_TASK_PERIOD); val->intval = div_s64(data64, chip->pdata->r_sns); break; case POWER_SUPPLY_PROP_TEMP: @@ -1142,6 +1151,17 @@ static int max17042_probe(struct i2c_client *client, struct device *dev, int irq regmap_write(chip->regmap, MAX17042_LearnCFG, 0x0007); } + chip->task_period = MAX17042_DEFAULT_TASK_PERIOD; + if (chip->chip_type == MAXIM_DEVICE_TYPE_MAX77759) { + ret = regmap_read(chip->regmap, MAX17042_TaskPeriod, &val); + if (ret) + return dev_err_probe(dev, ret, + "failed to read task period\n"); + chip->task_period = val; + } + dev_dbg(dev, "task period: %#.4x (%d)\n", chip->task_period, + chip->task_period); + chip->battery = devm_power_supply_register(dev, max17042_desc, &psy_cfg); if (IS_ERR(chip->battery)) diff --git a/include/linux/power/max17042_battery.h b/include/linux/power/max17042_battery.h index 05097f08ea36a..d5b08313cf113 100644 --- a/include/linux/power/max17042_battery.h +++ b/include/linux/power/max17042_battery.h @@ -17,6 +17,7 @@ #define MAX17042_DEFAULT_VMAX (4500) /* LiHV cell max */ #define MAX17042_DEFAULT_TEMP_MIN (0) /* For sys without temp sensor */ #define MAX17042_DEFAULT_TEMP_MAX (700) /* 70 degrees Celcius */ +#define MAX17042_DEFAULT_TASK_PERIOD (5760) /* Consider RepCap which is less then 10 units below FullCAP full */ #define MAX17042_FULL_THRESHOLD 10