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Diffstat (limited to 'Documentation/thermal/sysfs-api.txt')
| -rw-r--r-- | Documentation/thermal/sysfs-api.txt | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt index ca1a1a34970..88c02334e35 100644 --- a/Documentation/thermal/sysfs-api.txt +++ b/Documentation/thermal/sysfs-api.txt @@ -112,6 +112,29 @@ temperature) and throttle appropriate devices. trip: indicates which trip point the cooling devices is associated with in this thermal zone. +1.4 Thermal Zone Parameters +1.4.1 struct thermal_bind_params + This structure defines the following parameters that are used to bind + a zone with a cooling device for a particular trip point. + .cdev: The cooling device pointer + .weight: The 'influence' of a particular cooling device on this zone. + This is on a percentage scale. The sum of all these weights + (for a particular zone) cannot exceed 100. + .trip_mask:This is a bit mask that gives the binding relation between + this thermal zone and cdev, for a particular trip point. + If nth bit is set, then the cdev and thermal zone are bound + for trip point n. + .match: This call back returns success(0) if the 'tz and cdev' need to + be bound, as per platform data. +1.4.2 struct thermal_zone_params + This structure defines the platform level parameters for a thermal zone. + This data, for each thermal zone should come from the platform layer. + This is an optional feature where some platforms can choose not to + provide this data. + .governor_name: Name of the thermal governor used for this zone + .num_tbps: Number of thermal_bind_params entries for this zone + .tbp: thermal_bind_params entries + 2. sysfs attributes structure RO read only value @@ -126,6 +149,7 @@ Thermal zone device sys I/F, created once it's registered: |---type: Type of the thermal zone |---temp: Current temperature |---mode: Working mode of the thermal zone + |---policy: Thermal governor used for this zone |---trip_point_[0-*]_temp: Trip point temperature |---trip_point_[0-*]_type: Trip point type |---trip_point_[0-*]_hyst: Hysteresis value for this trip point @@ -187,6 +211,10 @@ mode charge of the thermal management. RW, Optional +policy + One of the various thermal governors used for a particular zone. + RW, Required + trip_point_[0-*]_temp The temperature above which trip point will be fired. Unit: millidegree Celsius @@ -264,6 +292,7 @@ method, the sys I/F structure will be built like this: |---type: acpitz |---temp: 37000 |---mode: enabled + |---policy: step_wise |---trip_point_0_temp: 100000 |---trip_point_0_type: critical |---trip_point_1_temp: 80000 @@ -305,3 +334,38 @@ to a thermal_zone_device when it registers itself with the framework. The event will be one of:{THERMAL_AUX0, THERMAL_AUX1, THERMAL_CRITICAL, THERMAL_DEV_FAULT}. Notification can be sent when the current temperature crosses any of the configured thresholds. + +5. Export Symbol APIs: + +5.1: get_tz_trend: +This function returns the trend of a thermal zone, i.e the rate of change +of temperature of the thermal zone. Ideally, the thermal sensor drivers +are supposed to implement the callback. If they don't, the thermal +framework calculated the trend by comparing the previous and the current +temperature values. + +5.2:get_thermal_instance: +This function returns the thermal_instance corresponding to a given +{thermal_zone, cooling_device, trip_point} combination. Returns NULL +if such an instance does not exist. + +5.3:notify_thermal_framework: +This function handles the trip events from sensor drivers. It starts +throttling the cooling devices according to the policy configured. +For CRITICAL and HOT trip points, this notifies the respective drivers, +and does actual throttling for other trip points i.e ACTIVE and PASSIVE. +The throttling policy is based on the configured platform data; if no +platform data is provided, this uses the step_wise throttling policy. + +5.4:thermal_cdev_update: +This function serves as an arbitrator to set the state of a cooling +device. It sets the cooling device to the deepest cooling state if +possible. + +5.5:thermal_register_governor: +This function lets the various thermal governors to register themselves +with the Thermal framework. At run time, depending on a zone's platform +data, a particular governor is used for throttling. + +5.6:thermal_unregister_governor: +This function unregisters a governor from the thermal framework. |