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: 479b6d0496 ("power: supply: add support for MAX1720x standalone fuel gauge")
Signed-off-by: Thomas Antoine <t.antoine@uclouvain.be>
Link: https://lore.kernel.org/r/20250523-b4-gs101_max77759_fg-v4-1-b49904e35a34@uclouvain.be
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
This commit is contained in:
Thomas Antoine 2025-05-23 14:51:44 +02:00 committed by Sebastian Reichel
parent 4deeea4b07
commit 58ae036172
1 changed files with 6 additions and 5 deletions

View File

@ -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);