power: supply: lego_ev3_battery: fix Vce offset
authorDavid Lechner <david@lechnology.com>
Fri, 20 Jul 2018 20:19:44 +0000 (15:19 -0500)
committerSebastian Reichel <sebastian.reichel@collabora.co.uk>
Sun, 22 Jul 2018 21:33:43 +0000 (23:33 +0200)
This fixes the value that accounts for the Vce of a transistor in the
LEGO MINDSTORMS EV3 power supply driver. The old value (200mV) was the
max value from the data sheet. After testing, the actual value has been
found to be 50mV. By using 50mV we get a more accurate voltage
indication.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
drivers/power/supply/lego_ev3_battery.c

index 6e3b3e384172b35b5e7fc04283def2368efd2806..1ae3710909b78ccfc2870b2c0200a173c69ffca8 100644 (file)
@@ -52,7 +52,7 @@ static int lego_ev3_battery_get_property(struct power_supply *psy,
                        return ret;
 
                val->intval *= 2000;
-               val->intval += 200000;
+               val->intval += 50000;
 
                /* plus adjust for shunt resistor drop */
                ret = iio_read_channel_processed(batt->iio_i, &val2);