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| author | Dmitry Osipenko <digetx@gmail.com> | 2021-04-23 05:09:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-22 11:57:40 +0300 |
| commit | cac8a7ac263642fff8cff6595b6d64c23384f07e (patch) | |
| tree | 953a965b108c8cf1bd92e26557bc40dda96d457f | |
| parent | d34cab87d2fb66c0efe3f1491bd5b21812b38938 (diff) | |
| download | linux-cac8a7ac263642fff8cff6595b6d64c23384f07e.tar.xz | |
iio: gyro: mpu3050: Fix reported temperature value
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>
| -rw-r--r-- | drivers/iio/gyro/mpu3050-core.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c index 3db843206db3..1096226a0612 100644 --- a/drivers/iio/gyro/mpu3050-core.c +++ b/drivers/iio/gyro/mpu3050-core.c @@ -270,7 +270,16 @@ 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: @@ -327,7 +336,7 @@ 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; |