This is a note to let you know that I've just added the patch titled
hwmon: (ltc2947) fix temperature scaling
to the 5.15-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:
hwmon-ltc2947-fix-temperature-scaling.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit db2daa1f3f6fc77de3420960e9c261b4609fcaa0
Author: Derek Nguyen <derek.nguyen@xxxxxxxxxxx>
Date: Thu Nov 10 13:21:08 2022 -0600
hwmon: (ltc2947) fix temperature scaling
[ Upstream commit 07e06193ead86d4812f431b4d87bbd4161222e3f ]
The LTC2947 datasheet (Rev. B) calls out in the section "Register
Description: Non-Accumulated Result Registers" (pg. 30) that "To
calculate temperature, multiply the TEMP register value by 0.204°C
and add 5.5°C". Fix to add 5.5C and not 0.55C.
Fixes: 9f90fd652bed ("hwmon: Add support for ltc2947")
Signed-off-by: Derek Nguyen <derek.nguyen@xxxxxxxxxxx>
Signed-off-by: Brandon Maier <brandon.maier@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221110192108.20624-1-brandon.maier@xxxxxxxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hwmon/ltc2947-core.c b/drivers/hwmon/ltc2947-core.c
index 5423466de697..e918490f3ff7 100644
--- a/drivers/hwmon/ltc2947-core.c
+++ b/drivers/hwmon/ltc2947-core.c
@@ -396,7 +396,7 @@ static int ltc2947_read_temp(struct device *dev, const u32 attr, long *val,
return ret;
/* in milidegrees celcius, temp is given by: */
- *val = (__val * 204) + 550;
+ *val = (__val * 204) + 5500;
return 0;
}
