Commit c0214f98 authored by Fabio Baltieri's avatar Fabio Baltieri Committed by Guenter Roeck
Browse files

hwmon: (ina2xx) Cast to s16 on shunt and current regs 



All devices supported by ina2xx are bidirectional and report the
measured shunt voltage and power values as a signed 16 bit, but the
current driver implementation caches all registers as u16, leading
to an incorrect sign extension when reporting to userspace in
ina2xx_get_value().

This patch fixes the problem by casting the signed registers to s16.
Tested on an INA219.

Signed-off-by: default avatarFabio Baltieri <fabio.baltieri@gmail.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 5c02c392

drivers/hwmon/ina2xx.c

+4 −3
Original line number Diff line number Diff line
@@ -148,7 +148,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg) 


	switch (reg) {

	case INA2XX_SHUNT_VOLTAGE:

		val = DIV_ROUND_CLOSEST(data->regs[reg],

		/* signed register */

		val = DIV_ROUND_CLOSEST((s16)data->regs[reg],

					data->config->shunt_div);

		break;

	case INA2XX_BUS_VOLTAGE:
@@ -160,8 +161,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg) 
		val = data->regs[reg] * data->config->power_lsb;

		break;

	case INA2XX_CURRENT:

		/* LSB=1mA (selected). Is in mA */

		val = data->regs[reg];

		/* signed register, LSB=1mA (selected), in mA */

		val = (s16)data->regs[reg];

		break;

	default:

		/* programmer goofed */

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