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authorSascha Hauer <s.hauer@pengutronix.de>2016-06-22 16:42:01 +0800
committerZhang Rui <rui.zhang@intel.com>2016-09-27 14:02:16 +0800
commit060c034a974187e930b790957cafc5047cc30a40 (patch)
tree0afdf73e38e94d0bd704ba40ae283ee088df6179 /Documentation/thermal
parent032d4057291e9d017cf50be017cf09b169ff438f (diff)
downloadlinux-060c034a974187e930b790957cafc5047cc30a40.tar.bz2
thermal: Add support for hardware-tracked trip points
This adds support for hardware-tracked trip points to the device tree thermal sensor framework. The framework supports an arbitrary number of trip points. Whenever the current temperature is updated, the trip points immediately below and above the current temperature are found. A .set_trips callback is then called with the temperatures. If there is no trip point above or below the current temperature, the passed trip temperature will be -INT_MAX or INT_MAX respectively. In this callback, the driver should program the hardware such that it is notified when either of these trip points are triggered. When a trip point is triggered, the driver should call `thermal_zone_device_update' for the respective thermal zone. This will cause the trip points to be updated again. If .set_trips is not implemented, the framework behaves as before. This patch is based on an earlier version from Mikko Perttunen <mikko.perttunen@kapsi.fi> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Caesar Wang <wxt@rock-chips.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Eduardo Valentin <edubezval@gmail.com> Cc: linux-pm@vger.kernel.org Reviewed-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Diffstat (limited to 'Documentation/thermal')
-rw-r--r--Documentation/thermal/sysfs-api.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 755476ea3fda..ef473dc7f55e 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -49,6 +49,9 @@ temperature) and throttle appropriate devices.
.bind: bind the thermal zone device with a thermal cooling device.
.unbind: unbind the thermal zone device with a thermal cooling device.
.get_temp: get the current temperature of the thermal zone.
+ .set_trips: set the trip points window. Whenever the current temperature
+ is updated, the trip points immediately below and above the
+ current temperature are found.
.get_mode: get the current mode (enabled/disabled) of the thermal zone.
- "enabled" means the kernel thermal management is enabled.
- "disabled" will prevent kernel thermal driver action upon trip points
@@ -95,6 +98,10 @@ temperature) and throttle appropriate devices.
get_temp: a pointer to a function that reads the
sensor temperature. This is mandatory
callback provided by sensor driver.
+ set_trips: a pointer to a function that sets a
+ temperature window. When this window is
+ left the driver must inform the thermal
+ core via thermal_zone_device_update.
get_trend: a pointer to a function that reads the
sensor temperature trend.
set_emul_temp: a pointer to a function that sets