From: Gregor Boirie Date: Wed, 17 Feb 2016 17:52:49 +0000 (+0100) Subject: iio:pressure:ms5611: fix ms5607 temp compensation X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ce5b8fc163619067aab157008daf5719cd38fdd1;p=openwrt%2Fstaging%2Fblogic.git iio:pressure:ms5611: fix ms5607 temp compensation Computation of sens2 was wrong and is fixed by this patch, sens2 should be: 2 * (t - 2000)^2 See page 8 of ms5607 datasheet here: http://www.meas-spec.com/product/pressure/MS5607-02BA03.aspx Signed-off-by: Gregor Boirie Acked-by: Lucas De Marchi Acked-by: Peter Meerwald-Stadler Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c index c7885f0c819f..84ab8d234a7f 100644 --- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -136,17 +136,17 @@ static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_inf t = 2000 + ((chip_info->prom[6] * dt) >> 23); if (t < 2000) { - s64 off2, sens2, t2; + s64 off2, sens2, t2, tmp; t2 = (dt * dt) >> 31; - off2 = (61 * (t - 2000) * (t - 2000)) >> 4; - sens2 = off2 << 1; + tmp = (t - 2000) * (t - 2000); + off2 = (61 * tmp) >> 4; + sens2 = tmp << 1; if (t < -1500) { - s64 tmp = (t + 1500) * (t + 1500); - + tmp = (t + 1500) * (t + 1500); off2 += 15 * tmp; - sens2 += (8 * tmp); + sens2 += 8 * tmp; } t -= t2;