Commit 58ae0361 authored by Thomas Antoine's avatar Thomas Antoine Committed by Sebastian Reichel
Browse files

power: supply: max1720x correct capacity computation 



From the datasheet of the MAX17201/17205, the LSB should be "5.0μVh/RSENSE".
The current computation sets it at 0.5mAh=5.0μVh/10mOhm, which does not take
into account the value of rsense (which is in 10µV steps) which can be
different from 10mOhm.

Change the computation to fit the specs.

Fixes: 479b6d04 ("power: supply: add support for MAX1720x standalone fuel gauge")
Signed-off-by: default avatarThomas Antoine <t.antoine@uclouvain.be>
Link: https://lore.kernel.org/r/20250523-b4-gs101_max77759_fg-v4-1-b49904e35a34@uclouvain.be


Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent 4deeea4b

drivers/power/supply/max1720x_battery.c

+6 −5
Original line number Diff line number Diff line
@@ -288,9 +288,10 @@ static int max172xx_voltage_to_ps(unsigned int reg) 
	return reg * 1250;	/* in uV */

}



static int max172xx_capacity_to_ps(unsigned int reg)

static int max172xx_capacity_to_ps(unsigned int reg,

				   struct max1720x_device_info *info)

{

	return reg * 500;	/* in uAh */

	return reg * (500000 / info->rsense);	/* in uAh */

}



/*
@@ -394,11 +395,11 @@ static int max1720x_battery_get_property(struct power_supply *psy, 
		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);

		val->intval = max172xx_capacity_to_ps(reg_val, info);

		break;

	case POWER_SUPPLY_PROP_CHARGE_AVG:

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

		val->intval = max172xx_capacity_to_ps(reg_val);

		val->intval = max172xx_capacity_to_ps(reg_val, info);

		break;

	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:

		ret = regmap_read(info->regmap, MAX172XX_TTE, &reg_val);
@@ -422,7 +423,7 @@ static int max1720x_battery_get_property(struct power_supply *psy, 
		break;

	case POWER_SUPPLY_PROP_CHARGE_FULL:

		ret = regmap_read(info->regmap, MAX172XX_FULL_CAP, &reg_val);

		val->intval = max172xx_capacity_to_ps(reg_val);

		val->intval = max172xx_capacity_to_ps(reg_val, info);

		break;

	case POWER_SUPPLY_PROP_MODEL_NAME:

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