Commit f73c7307 authored Apr 23, 2021 by Dmitry Osipenko Committed by Jonathan Cameron May 10, 2021

iio: gyro: mpu3050: Fix reported temperature value

The raw temperature value is a 16-bit signed integer. The sign casting
is missing in the code, which results in a wrong temperature reported
by userspace tools, fix it.

Cc: stable@vger.kernel.org
Fixes: 3904b28e ("iio: gyro: Add driver for the MPU-3050 gyroscope")
Datasheet: https://www.cdiweb.com/datasheets/invensense/mpu-3000a.pdf


Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T
Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # Asus TF201
Reported-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Andy Shevchenko <Andy.Shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Link: https://lore.kernel.org/r/20210423020959.5023-1-digetx@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

parent 70618035

drivers/iio/gyro/mpu3050-core.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -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
		* for the "best fit straight line" temperature range
		* of -30C..85C. The 23000 includes room temperature
		* offset of +35C, 280 is the precision scale and x is
		* the 16-bit signed integer reported by hardware.
		*
		* 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;