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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2016-01-21 01:07:31 +0900 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-01-30 16:07:32 +0000 |
| commit | 431386e783a3a6c8b7707bee32d18c353b8688b2 (patch) | |
| tree | f1443db133e55388affeb9f50754e9c74b77af3c /drivers/iio/pressure/mpl115.c | |
| parent | d81dac3c1c5295c61b15293074ac2bd3254e1875 (diff) | |
| download | blackbird-op-linux-431386e783a3a6c8b7707bee32d18c353b8688b2.tar.gz blackbird-op-linux-431386e783a3a6c8b7707bee32d18c353b8688b2.zip | |
iio: pressure: mpl115: fix temperature offset sign
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>
Diffstat (limited to 'drivers/iio/pressure/mpl115.c')
| -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: |
