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Diffstat (limited to 'Documentation/thermal/sysfs-api.txt')
| -rw-r--r-- | Documentation/thermal/sysfs-api.txt | 112 |
1 files changed, 90 insertions, 22 deletions
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt index 8c745c893..efc3f3d29 100644 --- a/Documentation/thermal/sysfs-api.txt +++ b/Documentation/thermal/sysfs-api.txt @@ -69,8 +69,76 @@ temperature) and throttle appropriate devices. 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. + 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. 1.2 thermal cooling device interface 1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name, @@ -78,32 +146,32 @@ temperature) and throttle appropriate devices. 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 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. @@ -116,13 +184,13 @@ temperature) and throttle appropriate devices. 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 @@ -142,13 +210,13 @@ temperature) and throttle appropriate devices. 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. - .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 <lower-state upper-state> of state limits. Each trip - will be associated with one state limit tuple when binding. - A NULL pointer means <THERMAL_NO_LIMITS THERMAL_NO_LIMITS> - on all trips. These limits are used when binding a cdev to a - trip point. + .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 <lower-state upper-state> of + state limits. Each trip will be associated with one state + limit tuple when binding. A NULL pointer means + <THERMAL_NO_LIMITS THERMAL_NO_LIMITS> 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 @@ -283,8 +351,8 @@ cdev[0-*] 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 |