thermal: Add support for hardware-tracked trip points
authorSascha Hauer <s.hauer@pengutronix.de>
Wed, 22 Jun 2016 08:42:01 +0000 (16:42 +0800)
committerZhang Rui <rui.zhang@intel.com>
Tue, 27 Sep 2016 06:02:16 +0000 (14:02 +0800)
commit060c034a974187e930b790957cafc5047cc30a40
tree0afdf73e38e94d0bd704ba40ae283ee088df6179
parent032d4057291e9d017cf50be017cf09b169ff438f
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>
Documentation/thermal/sysfs-api.txt
drivers/thermal/thermal_core.c
include/linux/thermal.h