iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

iio: gyro: mpu3050: Fix reported temperature value

Browse Source 
commit f73c730774d88a14d7b60feee6d0e13570f99499 upstream.

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: 3904b28efb2c ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Osipenko 2021-04-23 05:09:59 +03:00 committed by Greg Kroah-Hartman
parent 70698dda4b
commit e8c6852bdb
1 changed files with 11 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/iio/gyro/mpu3050-core.c
View File

@ -271,7 +271,16 @@ 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:
@ -328,7 +337,7 @@ 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;