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authorPunit Agrawal <punit.agrawal@arm.com>2015-02-26 19:00:32 +0000
committerEduardo Valentin <edubezval@gmail.com>2015-05-04 21:27:52 -0700
commit647f99255d604aa98f919b89c74567bb4e8fe52c (patch)
treebe4c02c950d3a92b27086996fcee8df0b4dda5f7
parent6828a4711f994bbd9d3fd27b7a541217fc37b341 (diff)
downloadlinux-647f99255d604aa98f919b89c74567bb4e8fe52c.tar.bz2
of: thermal: Introduce sustainable power for a thermal zone
Introduce an optional property called, sustainable-power, which represents the power (in mW) which the thermal zone can safely dissipate. If provided the property is parsed and associated with the thermal zone via the thermal zone parameters. Cc: Zhang Rui <rui.zhang@intel.com> Cc: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
-rw-r--r--Documentation/devicetree/bindings/thermal/thermal.txt9
-rw-r--r--drivers/thermal/of-thermal.c4
2 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
index 29fe0bfae38e..8a49362dea6e 100644
--- a/Documentation/devicetree/bindings/thermal/thermal.txt
+++ b/Documentation/devicetree/bindings/thermal/thermal.txt
@@ -167,6 +167,13 @@ Optional property:
by means of sensor ID. Additional coefficients are
interpreted as constant offset.
+- sustainable-power: An estimate of the sustainable power (in mW) that the
+ Type: unsigned thermal zone can dissipate at the desired
+ Size: one cell control temperature. For reference, the
+ sustainable power of a 4'' phone is typically
+ 2000mW, while on a 10'' tablet is around
+ 4500mW.
+
Note: The delay properties are bound to the maximum dT/dt (temperature
derivative over time) in two situations for a thermal zone:
(i) - when passive cooling is activated (polling-delay-passive); and
@@ -546,6 +553,8 @@ thermal-zones {
*/
coefficients = <1200 -345 890>;
+ sustainable-power = <2500>;
+
trips {
/* Trips are based on resulting linear equation */
cpu_trip: cpu-trip {
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index c606b85ea9f4..705b21d01f1c 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -866,6 +866,7 @@ int __init of_parse_thermal_zones(void)
for_each_child_of_node(np, child) {
struct thermal_zone_device *zone;
struct thermal_zone_params *tzp;
+ u32 prop;
/* Check whether child is enabled or not */
if (!of_device_is_available(child))
@@ -892,6 +893,9 @@ int __init of_parse_thermal_zones(void)
/* No hwmon because there might be hwmon drivers registering */
tzp->no_hwmon = true;
+ if (!of_property_read_u32(child, "sustainable-power", &prop))
+ tzp->sustainable_power = prop;
+
zone = thermal_zone_device_register(child->name, tz->ntrips,
0, tz,
ops, tzp,