Commit f1da7f50 authored by Akinobu Mita's avatar Akinobu Mita Committed by Luis Henriques

iio: pressure: mpl115: fix temperature offset sign

commit 431386e7 upstream.

According to the datasheet, the resolusion of temperature sensor is
-5.35 counts/C. Temperature ADC is 472 counts at 25C.
(https://www.sparkfun.com/datasheets/Sensors/Pressure/MPL115A1.pdf
NOTE: This is older revision, but this information is removed from the
latest datasheet from nxp somehow)

Temp [C] = (Tadc - 472) / -5.35 + 25
         = (Tadc - 605.750000) * -0.186915888

So the correct offset is -605.750000.
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: default avatarPeter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent c7fbe9e7
......@@ -117,7 +117,7 @@ static int mpl115_read_raw(struct iio_dev *indio_dev,
*val = ret >> 6;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
*val = 605;
*val = -605;
*val2 = 750000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SCALE:
......
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