power: supply: axp20x_battery: properly report current when discharging

[ Upstream commit d4f408cdcd26921c1268cb8dcbe8ffb6faf837f3 ]

As stated in [1], negative current values are used for discharging
batteries.

AXP PMICs internally have two different ADC channels for shunt current
measurement: one used during charging and one during discharging.
The values reported by these ADCs are unsigned.
While the driver properly selects ADC channel to get the data from,
it doesn't apply negative sign when reporting discharging current.

[1] Documentation/ABI/testing/sysfs-class-power

Signed-off-by: Evgeny Boger <boger@wirenboard.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/power/supply/axp20x_battery.c b/drivers/power/supply/axp20x_battery.c
index 7494f0f0eadb2703a91b2005e266af557f3a9bed..a2e2443357fa5f1a614d7246e6cbed4b92deb3c8 100644 (file)
--- a/drivers/power/supply/axp20x_battery.c
+++ b/drivers/power/supply/axp20x_battery.c
@@ -160,7 +160,6 @@ static int axp20x_battery_get_prop(struct power_supply *psy,
                                   union power_supply_propval *val)
 {
        struct axp20x_batt_ps *axp20x_batt = power_supply_get_drvdata(psy);
-       struct iio_channel *chan;
        int ret = 0, reg, val1;
 
        switch (psp) {
@@ -240,12 +239,12 @@ static int axp20x_battery_get_prop(struct power_supply *psy,
                if (ret)
                        return ret;
 
-               if (reg & AXP20X_PWR_STATUS_BAT_CHARGING)
-                       chan = axp20x_batt->batt_chrg_i;
-               else
-                       chan = axp20x_batt->batt_dischrg_i;
-
-               ret = iio_read_channel_processed(chan, &val->intval);
+               if (reg & AXP20X_PWR_STATUS_BAT_CHARGING) {
+                       ret = iio_read_channel_processed(axp20x_batt->batt_chrg_i, &val->intval);
+               } else {
+                       ret = iio_read_channel_processed(axp20x_batt->batt_dischrg_i, &val1);
+                       val->intval = -val1;
+               }
                if (ret)
                        return ret;