diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2015-10-07 13:10:54 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-11-09 12:50:25 -0800 |
| commit | ceb4781bbd0112809f71e5a5b55d7baf46128b4a (patch) | |
| tree | 8f529d3aed0e12f5c2d4d16f3e03be8125b32eed /drivers | |
| parent | 7fc5986496d4f18edec7ac5e5b7e0db45a58ff88 (diff) | |
iio: mxs-lradc: Fix temperature offset
commit b94e22805a2224061bb263a82b72e09544a5fbb3 upstream.
0° Kelvin is actually −273.15°C, not -272.15°C. Fix the temperature offset.
Also improve the comment explaining the calculation.
Reported-by: Janusz Użycki <j.uzycki@elpromaelectronics.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Marek Vasut <marex@denx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/iio/adc/mxs-lradc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c index 27e1a6e62d06..503846c3e620 100644 --- a/drivers/staging/iio/adc/mxs-lradc.c +++ b/drivers/staging/iio/adc/mxs-lradc.c @@ -920,11 +920,12 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev, case IIO_CHAN_INFO_OFFSET: if (chan->type == IIO_TEMP) { /* The calculated value from the ADC is in Kelvin, we - * want Celsius for hwmon so the offset is - * -272.15 * scale + * want Celsius for hwmon so the offset is -273.15 + * The offset is applied before scaling so it is + * actually -213.15 * 4 / 1.012 = -1079.644268 */ - *val = -1075; - *val2 = 691699; + *val = -1079; + *val2 = 644268; return IIO_VAL_INT_PLUS_MICRO; } |