hwmon: (ina2xx) Fix current value calculation

[ Upstream commit 38cd989ee38c16388cde89db5b734f9d55b905f9 ]

The current register (04h) has a sign bit at MSB. The comments
for this calculation also mention that it's a signed register.

However, the regval is unsigned type so result of calculation
turns out to be an incorrect value when current is negative.

This patch simply fixes this by adding a casting to s16.

Fixes: 5d389b1251 ("hwmon: (ina2xx) Make calibration register value fixed")
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Nicolin Chen 2018-11-13 19:48:54 -08:00 committed by Greg Kroah-Hartman
parent d70a6605fe
commit 3ef0d19cd8

View File

@ -274,7 +274,7 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
break;
case INA2XX_CURRENT:
/* signed register, result in mA */
val = regval * data->current_lsb_uA;
val = (s16)regval * data->current_lsb_uA;
val = DIV_ROUND_CLOSEST(val, 1000);
break;
case INA2XX_CALIBRATION: