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authorJavi Merino <javi.merino@arm.com>2015-02-18 16:04:24 +0000
committerEduardo Valentin <edubezval@gmail.com>2015-05-04 21:27:51 -0700
commitdb91651311c8b89978b17d27634582c28c33363e (patch)
tree67786b4eb698a3f3712a83a87ad89a0c267c1627 /Documentation/thermal/sysfs-api.txt
parent80b89172f9c3410764e0d962d6494c0af6d6dba8 (diff)
downloadop-kernel-dev-db91651311c8b89978b17d27634582c28c33363e.zip
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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>
Diffstat (limited to 'Documentation/thermal/sysfs-api.txt')
-rw-r--r--Documentation/thermal/sysfs-api.txt15
1 files changed, 14 insertions, 1 deletions
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 @@ thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
/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 @@ cdev[0-*]_trip_point
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 @@ passive, active. If an ACPI thermal zone supports critical, passive,
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 @@ method, the sys I/F structure will be built like this:
|---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
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