From d4f408cdcd26921c1268cb8dcbe8ffb6faf837f3 Mon Sep 17 00:00:00 2001
From: Evgeny Boger <boger@wirenboard.com>
Date: Wed, 12 Jan 2022 11:47:27 +0300
Subject: [PATCH] power: supply: axp20x_battery: properly report current when discharging
Git-commit: d4f408cdcd26921c1268cb8dcbe8ffb6faf837f3
Patch-mainline: v5.18-rc1
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/power/supply/axp20x_battery.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/power/supply/axp20x_battery.c b/drivers/power/supply/axp20x_battery.c
index 5d197141f476..9106077c0dbb 100644
--- a/drivers/power/supply/axp20x_battery.c
+++ b/drivers/power/supply/axp20x_battery.c
@@ -186,7 +186,6 @@ 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) {
@@ -266,12 +265,12 @@ 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;
 
-- 
2.31.1