| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 48/94] iio: mxs-lradc: Fix temperature offset | Date | Fri, 13 Nov 2015 10:09:42 +0000 |
| |
3.16.7-ckt20 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
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> Signed-off-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/staging/iio/adc/mxs-lradc.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c index 37a1192f1637..57563571c965 100644 --- a/drivers/staging/iio/adc/mxs-lradc.c +++ b/drivers/staging/iio/adc/mxs-lradc.c @@ -917,11 +917,12 @@ 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; }
|