| From | Kamal Mostafa <> | Subject | [PATCH 3.13 132/198] hwmon: (ina2xx) Cast to s16 on shunt and current regs | Date | Tue, 15 Jul 2014 14:30:02 -0700 |
| |
3.13.11.5 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Fabio Baltieri <fabio.baltieri@gmail.com>
commit c0214f98943b1fe43f7be61b7782b0c8f0836f28 upstream.
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: Fabio Baltieri <fabio.baltieri@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/hwmon/ina2xx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c index 93d26e8..bfd3f3e 100644 --- a/drivers/hwmon/ina2xx.c +++ b/drivers/hwmon/ina2xx.c @@ -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 */ -- 1.9.1
|