driver-api/thermal/sysfs-api.rst

15 The generic thermal sysfs provides a set of interfaces for thermal zone
19 This how-to focuses on enabling new thermal zone and cooling devices to
21 This solution is platform independent and any type of thermal zone devices
24 The main task of the thermal sysfs driver is to expose thermal zone attributes
27 inputs from thermal zone attributes (the current temperature and trip point
36 1.1 thermal zone device interface
48     This interface function adds a new thermal zone device (sensor) to
53 	the thermal zone type.
55 	the total number of trip points this thermal zone supports.
61 	thermal zone device call-backs.
64 		bind the thermal zone device with a thermal cooling device.
66 		unbind the thermal zone device with a thermal cooling device.
68 		get the current temperature of the thermal zone.
74 		   get the current mode (enabled/disabled) of the thermal zone.
82 		set the mode (enabled/disabled) of the thermal zone.
92 	thermal zone platform parameters.
104     This interface function removes the thermal zone device.
115 	This interface adds a new sensor to a DT thermal zone.
117 	device tree and look for the zone that refer to the sensor device
118 	pointed by dev->of_node as temperature providers. For the zone
120 	thermal zone device.
150 	The thermal zone temperature is provided by the get_temp() function
154 	It returns error pointer if fails otherwise valid thermal zone device
163 	This interface unregisters a sensor from a DT thermal zone which was
166 	thermal zone device registered with thermal_zone_of_sensor_register()
167 	interface. It will also silent the zone by remove the .get_temp() and
168 	get_trend() thermal zone device callbacks.
206 	for the thermal zone device, which might be useful for platform
214 	for the thermal zone device, which might be useful for platform
229     to all the thermal zone devices registered at the same time.
252     unbinds itself from all the thermal zone devices using it.
254 1.3 interface for binding a thermal zone device with a thermal cooling device
264     point of a thermal zone device.
266     This function is usually called in the thermal zone device .bind callback.
269 	  the thermal zone device
273 	  indicates which trip point in this thermal zone the cooling device
285 	  zone.  See 1.4.1 below for more information.
293     trip point of a thermal zone device. This function is usually called in
294     the thermal zone device .unbind callback.
297 	the thermal zone device
301 	indicates which trip point in this thermal zone the cooling device
304 1.4 Thermal Zone Parameters
312     a zone with a cooling device for a particular trip point.
318 	     zone. This is relative to the rest of the cooling
323 	     contribute to the cooling of this zone unless all cooling
328 	       this thermal zone and cdev, for a particular trip point.
329 	       If nth bit is set, then the cdev and thermal zone are bound
347     This structure defines the platform level parameters for a thermal zone.
348     This data, for each thermal zone should come from the platform layer.
353 	       Name of the thermal governor used for this zone
361 	       Number of thermal_bind_params entries for this zone
378 Thermal zone device sys I/F, created once it's registered::
381     |---type:			Type of the thermal zone
383     |---mode:			Working mode of the thermal zone
384     |---policy:			Thermal governor used for this zone
385     |---available_policies:	Available thermal governors for this zone
413 the relationship between a thermal zone and its associated cooling device.
420     |---cdev[0-*]:		[0-*]th cooling device in current thermal zone
423 				this thermal zone
425 Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
427 of thermal zone device. E.g. the generic thermal driver registers one hwmon
434     |---name:			The type of the thermal zone devices
435     |---temp[1-*]_input:	The current temperature of thermal zone [1-*]
436     |---temp[1-*]_critical:	The critical trip point of thermal zone [1-*]
440 Thermal zone attributes
444 	Strings which represent the thermal zone type.
445 	This is given by thermal zone driver as part of registration.
452 	Current temperature as reported by thermal zone (sensor).
459 	managing the thermal zone. It can be either default kernel based
465 			  Preventing kernel thermal zone driver actions upon
472 	One of the various thermal governors used for a particular zone.
477 	Available thermal governors which can be used for a particular zone.
492 	thermal zone.
508 	The trip point in this thermal zone which `cdev[0-*]` is associated
515 	The influence of `cdev[0-*]` in this thermal zone. This value
517 	zone. For example, if a cooling device has a weight double
519 	thermal zone.
527 	passive trip point for the zone. Activation is done by polling with
537 	Interface to set the emulated temperature method in thermal zone
538 	(sensor). After setting this temperature, the thermal zone may pass
554 	the thermal zone. Used by the power allocator governor. For
679 ACPI thermal zone may support multiple trip points like critical, hot,
680 passive, active. If an ACPI thermal zone supports critical, passive,
685 effectiveness in cooling the thermal zone.
734 This function returns the trend of a thermal zone, i.e the rate of change
735 of temperature of the thermal zone. Ideally, the thermal sensor drivers