--- zzzz-none-000/linux-3.10.107/Documentation/thermal/sysfs-api.txt 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/Documentation/thermal/sysfs-api.txt 2021-02-04 17:41:59.000000000 +0000 @@ -49,6 +49,9 @@ .bind: bind the thermal zone device with a thermal cooling device. .unbind: unbind the thermal zone device with a thermal cooling device. .get_temp: get the current temperature of the thermal zone. + .set_trips: set the trip points window. Whenever the current temperature + is updated, the trip points immediately below and above the + current temperature are found. .get_mode: get the current mode (enabled/disabled) of the thermal zone. - "enabled" means the kernel thermal management is enabled. - "disabled" will prevent kernel thermal driver action upon trip points @@ -69,8 +72,92 @@ 1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz) This interface function removes the thermal zone device. - It deletes the corresponding entry form /sys/class/thermal folder and - unbind all the thermal cooling devices it uses. + It deletes the corresponding entry from /sys/class/thermal folder and + unbinds all the thermal cooling devices it uses. + +1.1.3 struct thermal_zone_device *thermal_zone_of_sensor_register( + struct device *dev, int sensor_id, void *data, + const struct thermal_zone_of_device_ops *ops) + + This interface adds a new sensor to a DT thermal zone. + This function will search the list of thermal zones described in + device tree and look for the zone that refer to the sensor device + pointed by dev->of_node as temperature providers. For the zone + pointing to the sensor node, the sensor will be added to the DT + thermal zone device. + + The parameters for this interface are: + dev: Device node of sensor containing valid node pointer in + dev->of_node. + sensor_id: a sensor identifier, in case the sensor IP has more + than one sensors + data: a private pointer (owned by the caller) that will be + passed back, when a temperature reading is needed. + ops: struct thermal_zone_of_device_ops *. + + get_temp: a pointer to a function that reads the + sensor temperature. This is mandatory + callback provided by sensor driver. + set_trips: a pointer to a function that sets a + temperature window. When this window is + left the driver must inform the thermal + core via thermal_zone_device_update. + get_trend: a pointer to a function that reads the + sensor temperature trend. + set_emul_temp: a pointer to a function that sets + sensor emulated temperature. + The thermal zone temperature is provided by the get_temp() function + pointer of thermal_zone_of_device_ops. When called, it will + have the private pointer @data back. + + It returns error pointer if fails otherwise valid thermal zone device + handle. Caller should check the return handle with IS_ERR() for finding + whether success or not. + +1.1.4 void thermal_zone_of_sensor_unregister(struct device *dev, + struct thermal_zone_device *tzd) + + This interface unregisters a sensor from a DT thermal zone which was + successfully added by interface thermal_zone_of_sensor_register(). + This function removes the sensor callbacks and private data from the + thermal zone device registered with thermal_zone_of_sensor_register() + interface. It will also silent the zone by remove the .get_temp() and + get_trend() thermal zone device callbacks. + +1.1.5 struct thermal_zone_device *devm_thermal_zone_of_sensor_register( + struct device *dev, int sensor_id, + void *data, const struct thermal_zone_of_device_ops *ops) + + This interface is resource managed version of + thermal_zone_of_sensor_register(). + All details of thermal_zone_of_sensor_register() described in + section 1.1.3 is applicable here. + The benefit of using this interface to register sensor is that it + is not require to explicitly call thermal_zone_of_sensor_unregister() + in error path or during driver unbinding as this is done by driver + resource manager. + +1.1.6 void devm_thermal_zone_of_sensor_unregister(struct device *dev, + struct thermal_zone_device *tzd) + + This interface is resource managed version of + thermal_zone_of_sensor_unregister(). + All details of thermal_zone_of_sensor_unregister() described in + section 1.1.4 is applicable here. + Normally this function will not need to be called and the resource + management code will ensure that the resource is freed. + +1.1.7 int thermal_zone_get_slope(struct thermal_zone_device *tz) + + This interface is used to read the slope attribute value + for the thermal zone device, which might be useful for platform + drivers for temperature calculations. + +1.1.8 int thermal_zone_get_offset(struct thermal_zone_device *tz) + + This interface is used to read the offset attribute value + for the thermal zone device, which might be useful for platform + drivers for temperature calculations. 1.2 thermal cooling device interface 1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name, @@ -78,62 +165,77 @@ This interface function adds a new thermal cooling device (fan/processor/...) to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself - to all the thermal zone devices register at the same time. + to all the thermal zone devices registered at the same time. name: the cooling device name. devdata: device private data. ops: thermal cooling devices call-backs. .get_max_state: get the Maximum throttle state of the cooling device. - .get_cur_state: get the Current throttle state of the cooling device. + .get_cur_state: get the Currently requested throttle state of the cooling device. .set_cur_state: set the Current throttle state of the cooling device. 1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev) - This interface function remove the thermal cooling device. - It deletes the corresponding entry form /sys/class/thermal folder and - unbind itself from all the thermal zone devices using it. + This interface function removes the thermal cooling device. + It deletes the corresponding entry from /sys/class/thermal folder and + unbinds itself from all the thermal zone devices using it. 1.3 interface for binding a thermal zone device with a thermal cooling device 1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, int trip, struct thermal_cooling_device *cdev, - unsigned long upper, unsigned long lower); + unsigned long upper, unsigned long lower, unsigned int weight); - This interface function bind a thermal cooling device to the certain trip + This interface function binds a thermal cooling device to a particular trip point of a thermal zone device. This function is usually called in the thermal zone device .bind callback. tz: the thermal zone device cdev: thermal cooling device - trip: indicates which trip point the cooling devices is associated with - in this thermal zone. + trip: indicates which trip point in this thermal zone the cooling device + is associated with. upper:the Maximum cooling state for this trip point. THERMAL_NO_LIMIT means no upper limit, and the cooling device can be in max_state. lower:the Minimum cooling state can be used for this trip point. THERMAL_NO_LIMIT means no lower limit, and the cooling device can be in cooling state 0. + weight: the influence of this cooling device in this thermal + zone. See 1.4.1 below for more information. 1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, int trip, struct thermal_cooling_device *cdev); - This interface function unbind a thermal cooling device from the certain + This interface function unbinds a thermal cooling device from a particular trip point of a thermal zone device. This function is usually called in the thermal zone device .unbind callback. tz: the thermal zone device cdev: thermal cooling device - trip: indicates which trip point the cooling devices is associated with - in this thermal zone. + trip: indicates which trip point in this thermal zone the cooling device + is associated with. 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. + .weight: The 'influence' of a particular cooling device on this + zone. This is relative to the rest of the cooling + devices. For example, if all cooling devices have a + weight of 1, then they all contribute the same. You can + use percentages if you want, but it's not mandatory. A + weight of 0 means that this cooling device doesn't + contribute to the cooling of this zone unless all cooling + devices have a weight of 0. If all weights are 0, then + they all contribute the same. .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. + .binding_limits: This is an array of cooling state limits. Must have + exactly 2 * thermal_zone.number_of_trip_points. It is an + array consisting of tuples of + state limits. Each trip will be associated with one state + limit tuple when binding. A NULL pointer means + on all trips. + These limits are used when binding a cdev to a trip point. .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 @@ -142,6 +244,11 @@ 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 + .no_hwmon: a boolean to indicate if the thermal to hwmon sysfs interface + is required. when no_hwmon == false, a hwmon sysfs interface + will be created. when no_hwmon == true, nothing will be done. + In case the thermal_zone_params is NULL, the hwmon interface + will be created (for backward compatibility). .num_tbps: Number of thermal_bind_params entries for this zone .tbp: thermal_bind_params entries @@ -160,10 +267,19 @@ |---temp: Current temperature |---mode: Working mode of the thermal zone |---policy: Thermal governor used for this zone + |---available_policies: Available thermal governors 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 |---emul_temp: Emulated temperature set node + |---sustainable_power: Sustainable dissipatable power + |---k_po: Proportional term during temperature overshoot + |---k_pu: Proportional term during temperature undershoot + |---k_i: PID's integral term in the power allocator gov + |---k_d: PID's derivative term in the power allocator + |---integral_cutoff: Offset above which errors are accumulated + |---slope: Slope constant applied as linear extrapolation + |---offset: Offset constant applied as linear extrapolation Thermal cooling device sys I/F, created once it's registered: /sys/class/thermal/cooling_device[0-*]: @@ -180,6 +296,8 @@ /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_ @@ -226,6 +344,10 @@ One of the various thermal governors used for a particular zone. RW, Required +available_policies + Available thermal governors which can be used for a particular zone. + RO, Required + trip_point_[0-*]_temp The temperature above which trip point will be fired. Unit: millidegree Celsius @@ -248,11 +370,19 @@ RO, Optional cdev[0-*]_trip_point - The trip point with which cdev[0-*] is associated in this thermal - zone; -1 means the cooling device is not associated with any trip + The trip point in this thermal zone which cdev[0-*] is associated + with; -1 means the cooling device is not associated with any trip 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 @@ -277,6 +407,67 @@ because userland can easily disable the thermal policy by simply flooding this sysfs node with low temperature values. +sustainable_power + An estimate of the sustained power that can be dissipated by + the thermal zone. Used by the power allocator governor. For + more information see Documentation/thermal/power_allocator.txt + Unit: milliwatts + RW, Optional + +k_po + The proportional term of the power allocator governor's PID + controller during temperature overshoot. Temperature overshoot + is when the current temperature is above the "desired + temperature" trip point. For more information see + Documentation/thermal/power_allocator.txt + RW, Optional + +k_pu + The proportional term of the power allocator governor's PID + controller during temperature undershoot. Temperature undershoot + is when the current temperature is below the "desired + temperature" trip point. For more information see + Documentation/thermal/power_allocator.txt + RW, Optional + +k_i + The integral term of the power allocator governor's PID + controller. This term allows the PID controller to compensate + for long term drift. For more information see + Documentation/thermal/power_allocator.txt + RW, Optional + +k_d + The derivative term of the power allocator governor's PID + controller. For more information see + Documentation/thermal/power_allocator.txt + RW, Optional + +integral_cutoff + Temperature offset from the desired temperature trip point + above which the integral term of the power allocator + governor's PID controller starts accumulating errors. For + example, if integral_cutoff is 0, then the integral term only + accumulates error when temperature is above the desired + temperature trip point. For more information see + Documentation/thermal/power_allocator.txt + Unit: millidegree Celsius + RW, Optional + +slope + The slope constant used in a linear extrapolation model + to determine a hotspot temperature based off the sensor's + raw readings. It is up to the device driver to determine + the usage of these values. + RW, Optional + +offset + The offset constant used in a linear extrapolation model + to determine a hotspot temperature based off the sensor's + raw readings. It is up to the device driver to determine + the usage of these values. + RW, Optional + ***************************** * Cooling device attributes * ***************************** @@ -306,7 +497,8 @@ 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: @@ -318,6 +510,7 @@ |---temp: 37000 |---mode: enabled |---policy: step_wise + |---available_policies: step_wise fair_share |---trip_point_0_temp: 100000 |---trip_point_0_type: critical |---trip_point_1_temp: 80000 @@ -328,8 +521,10 @@ |---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