diff options
| author | Andreas Klinger <ak@it-klinger.de> | 2017-04-10 19:00:01 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-25 15:44:37 +0200 |
| commit | dfb450b2b66e4271c63c10f72c17e2a9967e511c (patch) | |
| tree | 422a1acd2fc4451ab9997a88c183c95bac95f0a3 /drivers/iio | |
| parent | a03176f92a02f0e1d1965c32b95d65a8bdbd6ac4 (diff) | |
IIO: bmp280-core.c: fix error in humidity calculation
commit ed3730c435f1a9f9559ed7762035d22d8a95adfe upstream.
While calculating the compensation of the humidity there are negative values
interpreted as unsigned because of unsigned variables used. These values as
well as the constants need to be casted to signed as indicated by the
documentation of the sensor.
Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/pressure/bmp280-core.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c index e5a533cbd53f..f762eb8b174a 100644 --- a/drivers/iio/pressure/bmp280-core.c +++ b/drivers/iio/pressure/bmp280-core.c @@ -175,11 +175,12 @@ static u32 bmp280_compensate_humidity(struct bmp280_data *data, } H6 = sign_extend32(tmp, 7); - var = ((s32)data->t_fine) - 76800; - var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + 16384) >> 15) - * (((((((var * H6) >> 10) * (((var * H3) >> 11) + 32768)) >> 10) - + 2097152) * H2 + 8192) >> 14); - var -= ((((var >> 15) * (var >> 15)) >> 7) * H1) >> 4; + var = ((s32)data->t_fine) - (s32)76800; + var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + + (s32)16384) >> 15) * (((((((var * H6) >> 10) + * (((var * (s32)H3) >> 11) + (s32)32768)) >> 10) + + (s32)2097152) * H2 + 8192) >> 14); + var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)H1) >> 4; return var >> 12; }; |