diff options
| author | Akinobu Mita <akinobu.mita@gmail.com> | 2016-01-21 01:07:31 +0900 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-04-11 22:07:36 -0400 |
| commit | 17fe8c8b306e4b76078b8b103e1f344970409378 (patch) | |
| tree | 7dd51315dbfe402f2950913e7a245516a26fa486 /drivers/iio | |
| parent | 5b20b25abab6faba0c91a4d7ccde93e134f29d6d (diff) | |
iio: pressure: mpl115: fix temperature offset sign
[ Upstream commit 431386e783a3a6c8b7707bee32d18c353b8688b2 ]
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: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/pressure/mpl115.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/iio/pressure/mpl115.c b/drivers/iio/pressure/mpl115.c index f5ecd6e19f5d..a0d7deeac62f 100644 --- a/drivers/iio/pressure/mpl115.c +++ b/drivers/iio/pressure/mpl115.c @@ -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: |