thermal: export weight to sysfs
It's useful to have access to the weights for the cooling devices for
thermal zones and change them if needed. Export them to sysfs.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 7ec632e..3625453 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -194,6 +194,8 @@
/sys/class/thermal/thermal_zone[0-*]:
|---cdev[0-*]: [0-*]th cooling device in current thermal zone
|---cdev[0-*]_trip_point: Trip point that cdev[0-*] is associated with
+ |---cdev[0-*]_weight: Influence of the cooling device in
+ this thermal zone
Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
the generic thermal driver also creates a hwmon sysfs I/F for each _type_
@@ -267,6 +269,14 @@
point.
RO, Optional
+cdev[0-*]_weight
+ The influence of cdev[0-*] in this thermal zone. This value
+ is relative to the rest of cooling devices in the thermal
+ zone. For example, if a cooling device has a weight double
+ than that of other, it's twice as effective in cooling the
+ thermal zone.
+ RW, Optional
+
passive
Attribute is only present for zones in which the passive cooling
policy is not supported by native thermal driver. Default is zero
@@ -320,7 +330,8 @@
active[0] and active[1] at the same time, it may register itself as a
thermal_zone_device (thermal_zone1) with 4 trip points in all.
It has one processor and one fan, which are both registered as
-thermal_cooling_device.
+thermal_cooling_device. Both are considered to have the same
+effectiveness in cooling the thermal zone.
If the processor is listed in _PSL method, and the fan is listed in _AL0
method, the sys I/F structure will be built like this:
@@ -342,8 +353,10 @@
|---trip_point_3_type: active1
|---cdev0: --->/sys/class/thermal/cooling_device0
|---cdev0_trip_point: 1 /* cdev0 can be used for passive */
+ |---cdev0_weight: 1024
|---cdev1: --->/sys/class/thermal/cooling_device3
|---cdev1_trip_point: 2 /* cdev1 can be used for active[0]*/
+ |---cdev1_weight: 1024
|cooling_device0:
|---type: Processor