thermal: doc: Add details of thermal_zone_of_sensor_{register,unregister}

Add details of the interface thermal_zone_of_sensor_register() and
thermal_zone_of_sensor_unregister() in the thermal/sysfs-api.txt.

The details describes the functionality and parameter which
are passed to these interfaces.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
(cherry picked from commit 3a7fd9c737e2c124d20c351529316d71962cf6ca)

Bug 200233003

Change-Id: Ibc344c5f76cb4d8856128f090067406e1329f651
Signed-off-by: Srikar Srimath Tirumala <srikars@nvidia.com>
Reviewed-on: http://git-master/r/1240759
GVS: Gerrit_Virtual_Submit
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 10f062ea6bc2b4f04e09ca48ab194071da9f298a..1fa1c8149f3bf46baf35dc8901d31dd106472276 100644 (file)
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -72,6 +72,51 @@ temperature) and throttle appropriate devices.
     It deletes the corresponding entry form /sys/class/thermal folder and
     unbind 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.
+
 1.2 thermal cooling device interface
 1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
                void *devdata, struct thermal_cooling_device_ops *)