Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933610AbbKMKim (ORCPT ); Fri, 13 Nov 2015 05:38:42 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:48873 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932895AbbKMKMG (ORCPT ); Fri, 13 Nov 2015 05:12:06 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Alexandre Belloni , Jonathan Cameron , 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 Message-Id: <1447409428-12178-49-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1447409428-12178-1-git-send-email-luis.henriques@canonical.com> References: <1447409428-12178-1-git-send-email-luis.henriques@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1811 Lines: 47 3.16.7-ckt20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni 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 Signed-off-by: Alexandre Belloni Acked-by: Stefan Wahren Acked-by: Marek Vasut Signed-off-by: Jonathan Cameron Signed-off-by: Luis Henriques --- 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/