* Patch "iio: pressure: mpl115: fix temperature offset sign" has been added to the 4.4-stable tree
@ 2016-02-24 3:24 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2016-02-24 3:24 UTC (permalink / raw)
To: akinobu.mita, gregkh, jic23, pmeerw; +Cc: stable, stable-commits
This is a note to let you know that I've just added the patch titled
iio: pressure: mpl115: fix temperature offset sign
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-pressure-mpl115-fix-temperature-offset-sign.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From 431386e783a3a6c8b7707bee32d18c353b8688b2 Mon Sep 17 00:00:00 2001
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Thu, 21 Jan 2016 01:07:31 +0900
Subject: iio: pressure: mpl115: fix temperature offset sign
From: Akinobu Mita <akinobu.mita@gmail.com>
commit 431386e783a3a6c8b7707bee32d18c353b8688b2 upstream.
According to the datasheet, the resolusion of temperature sensor is
-5.35 counts/C. Temperature ADC is 472 counts at 25C.
(https://www.sparkfun.com/datasheets/Sensors/Pressure/MPL115A1.pdf
NOTE: This is older revision, but this information is removed from the
latest datasheet from nxp somehow)
Temp [C] = (Tadc - 472) / -5.35 + 25
= (Tadc - 605.750000) * -0.186915888
So the correct offset is -605.750000.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/pressure/mpl115.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/iio/pressure/mpl115.c
+++ b/drivers/iio/pressure/mpl115.c
@@ -117,7 +117,7 @@ static int mpl115_read_raw(struct iio_de
*val = ret >> 6;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
- *val = 605;
+ *val = -605;
*val2 = 750000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SCALE:
Patches currently in stable-queue which might be from akinobu.mita@gmail.com are
queue-4.4/iio-pressure-mpl115-fix-temperature-offset-sign.patch
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2016-02-24 3:24 Patch "iio: pressure: mpl115: fix temperature offset sign" has been added to the 4.4-stable tree gregkh
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