The raw temperature value is a signed 16bit integer. The sign casting is missed in the code, which results in a wrong temperature reported by userspace tools, fix it. Cc: stable@xxxxxxxxxxxxxxx Link: https://www.cdiweb.com/datasheets/invensense/mpu-3000a.pdf Tested-by: Maxim Schwalm <maxim.schwalm@xxxxxxxxx> # Asus TF700T Tested-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx> # Asus TF201 Reported-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> --- drivers/iio/gyro/mpu3050-core.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c index ac90be03332a..9885428ca12e 100644 --- a/drivers/iio/gyro/mpu3050-core.c +++ b/drivers/iio/gyro/mpu3050-core.c @@ -272,7 +272,16 @@ static int mpu3050_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_OFFSET: switch (chan->type) { case IIO_TEMP: - /* The temperature scaling is (x+23000)/280 Celsius */ + /* + * The temperature scaling is (x+23000)/280 Celsius, + * where 23000 includes room temperature offset of + * +35C, 280 is the precision scale and x is the signed + * 16bit integer which corresponds to the temperature + * range of -40C..85C. + * + * Temperature value itself represents temperature of + * the sensor die. + */ *val = 23000; return IIO_VAL_INT; default: @@ -329,7 +338,7 @@ static int mpu3050_read_raw(struct iio_dev *indio_dev, goto out_read_raw_unlock; } - *val = be16_to_cpu(raw_val); + *val = (s16)be16_to_cpu(raw_val); ret = IIO_VAL_INT; goto out_read_raw_unlock; -- 2.30.2
