[PATCH v1 1/9] power: supply: max17042_battery: Put LSB units into defines

From: Vincent Cloutier

Date: Mon Apr 06 2026 - 16:58:32 EST


From: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@xxxxxxx>

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@xxxxxxx>
---
drivers/power/supply/max17042_battery.c | 36 ++++++++++++++-----------
1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index acea176101fa..a6798b9a1c82 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -52,6 +52,13 @@

#define MAX17042_VMAX_TOLERANCE 50 /* 50 mV */

+#define MAX17042_CURRENT_LSB 1562500ll /* 1.5625µV/Rsense */
+#define MAX17042_CAPACITY_LSB 5000000ll /* 5.0µVH/Rsense */
+#define MAX17042_TIME_LSB 5625 / 1000 /* s */
+#define MAX17042_VOLTAGE_LSB 625 / 8 /* µV */
+#define MAX17042_RESISTANCE_LSB 1 / 4096 /* Ω */
+#define MAX17042_TEMPERATURE_LSB 1 / 256 /* °C */
+
struct max17042_chip {
struct device *dev;
struct regmap *regmap;
@@ -105,8 +112,7 @@ static int max17042_get_temperature(struct max17042_chip *chip, int *temp)

*temp = sign_extend32(data, 15);
/* The value is converted into deci-centigrade scale */
- /* Units of LSB = 1 / 256 degree Celsius */
- *temp = *temp * 10 / 256;
+ *temp = *temp * 10 * MAX17042_TEMPERATURE_LSB;
return 0;
}

@@ -183,7 +189,7 @@ static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
goto health_error;

/* bits [0-3] unused */
- vavg = val * 625 / 8;
+ vavg = val * MAX17042_VOLTAGE_LSB;
/* Convert to millivolts */
vavg /= 1000;

@@ -192,7 +198,7 @@ static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
goto health_error;

/* bits [0-3] unused */
- vbatt = val * 625 / 8;
+ vbatt = val * MAX17042_VOLTAGE_LSB;
/* Convert to millivolts */
vbatt /= 1000;

@@ -299,21 +305,21 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- val->intval = data * 625 / 8;
+ val->intval = data * MAX17042_VOLTAGE_LSB;
break;
case POWER_SUPPLY_PROP_VOLTAGE_AVG:
ret = regmap_read(map, MAX17042_AvgVCELL, &data);
if (ret < 0)
return ret;

- val->intval = data * 625 / 8;
+ val->intval = data * MAX17042_VOLTAGE_LSB;
break;
case POWER_SUPPLY_PROP_VOLTAGE_OCV:
ret = regmap_read(map, MAX17042_OCVInternal, &data);
if (ret < 0)
return ret;

- val->intval = data * 625 / 8;
+ val->intval = data * MAX17042_VOLTAGE_LSB;
break;
case POWER_SUPPLY_PROP_CAPACITY:
if (chip->pdata->enable_current_sense)
@@ -330,7 +336,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 5000000ll;
+ data64 = data * MAX17042_CAPACITY_LSB;
do_div(data64, chip->pdata->r_sns);
val->intval = data64;
break;
@@ -339,7 +345,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 5000000ll;
+ data64 = data * MAX17042_CAPACITY_LSB;
do_div(data64, chip->pdata->r_sns);
val->intval = data64;
break;
@@ -348,7 +354,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 5000000ll;
+ data64 = data * MAX17042_CAPACITY_LSB;
do_div(data64, chip->pdata->r_sns);
val->intval = data64;
break;
@@ -357,7 +363,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = sign_extend64(data, 15) * 5000000ll;
+ data64 = sign_extend64(data, 15) * MAX17042_CAPACITY_LSB;
val->intval = div_s64(data64, chip->pdata->r_sns);
break;
case POWER_SUPPLY_PROP_TEMP:
@@ -399,7 +405,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = sign_extend64(data, 15) * 1562500ll;
+ data64 = sign_extend64(data, 15) * MAX17042_CURRENT_LSB;
val->intval = div_s64(data64, chip->pdata->r_sns);
} else {
return -EINVAL;
@@ -411,7 +417,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = sign_extend64(data, 15) * 1562500ll;
+ data64 = sign_extend64(data, 15) * MAX17042_CURRENT_LSB;
val->intval = div_s64(data64, chip->pdata->r_sns);
} else {
return -EINVAL;
@@ -422,7 +428,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 1562500ll;
+ data64 = data * MAX17042_CURRENT_LSB;
val->intval = div_s64(data64, chip->pdata->r_sns);
break;
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
@@ -430,7 +436,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- val->intval = data * 5625 / 1000;
+ val->intval = data * MAX17042_TIME_LSB;
break;
default:
return -EINVAL;
--
2.53.0