[PATCH 2/4] power: max17042_battery: Improve accuracy of current_now and current_avg readings

From: Sebastian Krzyszkowiak
Date: Tue Nov 24 2020 - 23:46:22 EST


Dividing 1562500 by r_sns value usually doesn't result in an integer.

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@xxxxxxx>
---
drivers/power/supply/max17042_battery.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index 2e9672fe4df1..86adccb0f32d 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -395,8 +395,8 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- val->intval = sign_extend32(data, 15);
- val->intval *= 1562500 / chip->pdata->r_sns;
+ data64 = sign_extend64(data, 15) * 1562500ll;
+ val->intval = div_s64(data64, chip->pdata->r_sns);
} else {
return -EINVAL;
}
@@ -407,8 +407,8 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- val->intval = sign_extend32(data, 15);
- val->intval *= 1562500 / chip->pdata->r_sns;
+ data64 = sign_extend64(data, 15) * 1562500ll;
+ val->intval = div_s64(data64, chip->pdata->r_sns);
} else {
return -EINVAL;
}
--
2.29.2