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authorZhang Rui <rui.zhang@intel.com>2012-06-27 09:54:33 +0800
committerZhang Rui <rui.zhang@intel.com>2012-09-24 14:44:36 +0800
commit601f3d4242be6ed6f72a2aadabc91e8255dad811 (patch)
tree497f09fcf665c066e4efc5d9542b33f021632ea9 /drivers/thermal
parent9d99842f99d847191ebd0c28469d2c70fcc5bf9e (diff)
Thermal: Introduce .get_trend() callback.
According to ACPI spec, tc1 and tc2 are used by OSPM to anticipate the temperature trends. We introduced the same concept to the generic thermal layer for passive cooling, but now it seems that these values are hard to be used on other platforms. So We introduce .get_trend() as a more general solution. For the platform thermal drivers that have their own way to anticipate the temperature trends, they should provide their own .get_trend() callback. Or else, we will calculate the temperature trends by simply comparing the current temperature and the cached previous temperature reading. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Valentin, Eduardo <eduardo.valentin@ti.com>
Diffstat (limited to 'drivers/thermal')
-rw-r--r--drivers/thermal/thermal_sys.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index b04fe2c4b0d5..146aa043f15b 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -723,6 +723,20 @@ static void thermal_zone_device_passive(struct thermal_zone_device *tz,
struct thermal_cooling_device *cdev;
long state, max_state;
+ if (!tz->ops->get_trend ||
+ tz->ops->get_trend(tz, trip, (enum thermal_trend *)&trend)) {
+ /*
+ * compare the current temperature and previous temperature
+ * to get the thermal trend, if no special requirement
+ */
+ if (tz->temperature > tz->last_temperature)
+ trend = THERMAL_TREND_RAISING;
+ else if (tz->temperature < tz->last_temperature)
+ trend = THERMAL_TREND_DROPPING;
+ else
+ trend = THERMAL_TREND_STABLE;
+ }
+
/*
* Above Trip?
* -----------
@@ -1091,6 +1105,9 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
goto leave;
}
+ tz->last_temperature = tz->temperature;
+ tz->temperature = temp;
+
for (count = 0; count < tz->trips; count++) {
tz->ops->get_trip_type(tz, count, &trip_type);
tz->ops->get_trip_temp(tz, count, &trip_temp);
@@ -1150,8 +1167,6 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
thermal_zone_device_passive(tz, temp, tz->forced_passive,
THERMAL_TRIPS_NONE);
- tz->last_temperature = temp;
-
leave:
if (tz->passive)
thermal_zone_device_set_polling(tz, tz->passive_delay);