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| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2015-10-07 13:10:54 +0200 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-11-15 12:51:49 -0500 |
| commit | 5b5ca1505596fe6906587ba22d85881cd7c57725 (patch) | |
| tree | 70fff97dc3014f38a6ad819e7723acbd24ee719f | |
| parent | 0a1bf5fd80e14a2396c6991d78b544ece3edf488 (diff) | |
| download | lwn-5b5ca1505596fe6906587ba22d85881cd7c57725.tar.gz lwn-5b5ca1505596fe6906587ba22d85881cd7c57725.zip | |
iio: mxs-lradc: Fix temperature offset
[ Upstream commit b94e22805a2224061bb263a82b72e09544a5fbb3 ]
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: Sasha Levin <sasha.levin@oracle.com>
| -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 ffd42071a12e..6050c58db682 100644 --- a/drivers/staging/iio/adc/mxs-lradc.c +++ b/drivers/staging/iio/adc/mxs-lradc.c @@ -910,11 +910,12 @@ 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; } |