From: Derek Nguyen <derek.nguyen@collins.com>
Date: Thu, 10 Nov 2022 19:21:08 +0000 (-0600)
Subject: hwmon: (ltc2947) fix temperature scaling
X-Git-Tag: v6.1~47^2~6
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=07e06193ead86d4812f431b4d87bbd4161222e3f;p=platform%2Fkernel%2Flinux-starfive.git

hwmon: (ltc2947) fix temperature scaling

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@collins.com>
Signed-off-by: Brandon Maier <brandon.maier@collins.com>
Link: https://lore.kernel.org/r/20221110192108.20624-1-brandon.maier@collins.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---

diff --git a/drivers/hwmon/ltc2947-core.c b/drivers/hwmon/ltc2947-core.c
index 7404e97..2dbbbac 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;
 }