From 601f3d4242be6ed6f72a2aadabc91e8255dad811 Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Wed, 27 Jun 2012 09:54:33 +0800 Subject: 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 Reviewed-by: Rafael J. Wysocki Reviewed-by: Valentin, Eduardo --- drivers/thermal/thermal_sys.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'drivers/thermal') 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); -- cgit v1.2.3-59-g8ed1b