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authorEzequiel Garcia <ezequiel.garcia@free-electrons.com>2013-03-22 16:23:03 +0400
committerZhang Rui <rui.zhang@intel.com>2013-03-26 18:13:10 +0400
commit2fd1db8819fbf73b5f74b4b4a205ab7be0957944 (patch)
tree19fee672d8511004571c6eda8f71bf5a7c764aea
parent696b6075afa97b42b3f59f96809ed586eb691c96 (diff)
downloadlinux-2fd1db8819fbf73b5f74b4b4a205ab7be0957944.tar.xz
thermal: dove: Fix thermal sensor formula
The currently formula has been taken from the 88AP510 SoC datasheet, which is not exactly correct. The correct value for the temperature in Celcius of the sensor present in this SoC is: Celsius = (322-reg)/1.3625 Signed-off-by: Lior Amsalem <alior@marvell.com> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Acked-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
-rw-r--r--drivers/thermal/dove_thermal.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/thermal/dove_thermal.c b/drivers/thermal/dove_thermal.c
index 3078c403b42d..4b15a5f270dc 100644
--- a/drivers/thermal/dove_thermal.c
+++ b/drivers/thermal/dove_thermal.c
@@ -107,12 +107,13 @@ static int dove_get_temp(struct thermal_zone_device *thermal,
}
/*
- * Calculate temperature. See Section 8.10.1 of 88AP510,
- * Documentation/arm/Marvell/README
+ * Calculate temperature. According to Marvell internal
+ * documentation the formula for this is:
+ * Celsius = (322-reg)/1.3625
*/
reg = readl_relaxed(priv->sensor);
reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
- *temp = ((2281638UL - (7298*reg)) / 10);
+ *temp = ((3220000000UL - (10000000UL * reg)) / 13625);
return 0;
}