Lines Matching +full:cooling +full:- +full:device
16 devices (sensors) and thermal cooling devices (fan, processor...) to register
19 This how-to focuses on enabling new thermal zone and cooling devices to
22 and cooling devices should be able to make use of the infrastructure.
25 as well as cooling device attributes to the user space.
30 - `[0-*]` denotes any positive number starting from 0
31 - `[1-*]` denotes any positive number starting from 1
36 1.1 thermal zone device interface
37 ---------------------------------
48 This interface function adds a new thermal zone device (sensor) to
49 /sys/class/thermal folder as `thermal_zone[0-*]`. It tries to bind all the
50 thermal cooling devices registered at the same time.
59 device private data
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.
76 - "enabled" means the kernel thermal management is
78 - "disabled" will prevent kernel thermal driver action
95 performing passive cooling.
104 This interface function removes the thermal zone device.
106 unbinds all the thermal cooling devices it uses.
111 *thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
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.
125 Device node of sensor containing valid node pointer in
126 dev->of_node.
154 It returns error pointer if fails otherwise valid thermal zone device
160 void thermal_zone_of_sensor_unregister(struct device *dev,
166 thermal zone device registered with thermal_zone_of_sensor_register()
168 get_trend() thermal zone device callbacks.
173 *devm_thermal_zone_of_sensor_register(struct device *dev,
191 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
206 for the thermal zone device, which might be useful for platform
214 for the thermal zone device, which might be useful for platform
217 1.2 thermal cooling device interface
218 ------------------------------------
227 This interface function adds a new thermal cooling device (fan/processor/...)
228 to /sys/class/thermal/ folder as `cooling_device[0-*]`. It tries to bind itself
232 the cooling device name.
234 device private data.
236 thermal cooling devices call-backs.
239 get the Maximum throttle state of the cooling device.
242 cooling device.
244 set the Current throttle state of the cooling device.
250 This interface function removes the thermal cooling device.
254 1.3 interface for binding a thermal zone device with a thermal cooling device
255 -----------------------------------------------------------------------------
263 This interface function binds a thermal cooling device to a particular trip
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
271 thermal cooling device
273 indicates which trip point in this thermal zone the cooling device
276 the Maximum cooling state for this trip point.
278 and the cooling device can be in max_state.
280 the Minimum cooling state can be used for this trip point.
282 and the cooling device can be in cooling state 0.
284 the influence of this cooling device in this thermal
292 This interface function unbinds a thermal cooling device from a particular
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
299 thermal cooling device
301 indicates which trip point in this thermal zone the cooling device
305 ---------------------------
312 a zone with a cooling device for a particular trip point.
315 The cooling device pointer
317 The 'influence' of a particular cooling device on this
318 zone. This is relative to the rest of the cooling
319 devices. For example, if all cooling devices have a
322 weight of 0 means that this cooling device doesn't
323 contribute to the cooling of this zone unless all cooling
332 This is an array of cooling state limits. Must have
334 array consisting of tuples <lower-state upper-state> of
378 Thermal zone device sys I/F, created once it's registered::
380 /sys/class/thermal/thermal_zone[0-*]:
381 |---type: Type of the thermal zone
382 |---temp: Current temperature
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
386 |---trip_point_[0-*]_temp: Trip point temperature
387 |---trip_point_[0-*]_type: Trip point type
388 |---trip_point_[0-*]_hyst: Hysteresis value for this trip point
389 |---emul_temp: Emulated temperature set node
390 |---sustainable_power: Sustainable dissipatable power
391 |---k_po: Proportional term during temperature overshoot
392 |---k_pu: Proportional term during temperature undershoot
393 |---k_i: PID's integral term in the power allocator gov
394 |---k_d: PID's derivative term in the power allocator
395 |---integral_cutoff: Offset above which errors are accumulated
396 |---slope: Slope constant applied as linear extrapolation
397 |---offset: Offset constant applied as linear extrapolation
399 Thermal cooling device sys I/F, created once it's registered::
401 /sys/class/thermal/cooling_device[0-*]:
402 |---type: Type of the cooling device(processor/fan/...)
403 |---max_state: Maximum cooling state of the cooling device
404 |---cur_state: Current cooling state of the cooling device
405 |---stats: Directory containing cooling device's statistics
406 |---stats/reset: Writing any value resets the statistics
407 |---stats/time_in_state_ms: Time (msec) spent in various cooling states
408 |---stats/total_trans: Total number of times cooling state is changed
409 |---stats/trans_table: Cooing state transition table
413 the relationship between a thermal zone and its associated cooling device.
419 /sys/class/thermal/thermal_zone[0-*]:
420 |---cdev[0-*]: [0-*]th cooling device in current thermal zone
421 |---cdev[0-*]_trip_point: Trip point that cdev[0-*] is associated with
422 |---cdev[0-*]_weight: Influence of the cooling device in
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
428 class device and build the associated hwmon sysfs I/F for all the registered
433 /sys/class/hwmon/hwmon[0-*]:
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-*]
438 Please read Documentation/hwmon/sysfs-interface.rst for additional information.
441 -----------------------
446 E.g: "acpitz" indicates it's an ACPI thermal device.
481 `trip_point_[0-*]_temp`
488 `trip_point_[0-*]_type`
491 E.g. it can be one of critical, hot, passive, `active[0-*]` for ACPI
496 `trip_point_[0-*]_hyst`
501 `cdev[0-*]`
502 Sysfs link to the thermal cooling device node where the sys I/F
503 for cooling device throttling control represents.
507 `cdev[0-*]_trip_point`
508 The trip point in this thermal zone which `cdev[0-*]` is associated
509 with; -1 means the cooling device is not associated with any trip
514 `cdev[0-*]_weight`
515 The influence of `cdev[0-*]` in this thermal zone. This value
516 is relative to the rest of cooling devices in the thermal
517 zone. For example, if a cooling device has a weight double
518 than that of other, it's twice as effective in cooling the
524 Attribute is only present for zones in which the passive cooling
541 threshold and its associated cooling action. This is write only node
555 more information see Documentation/driver-api/thermal/power_allocator.rst
566 Documentation/driver-api/thermal/power_allocator.rst
575 Documentation/driver-api/thermal/power_allocator.rst
583 Documentation/driver-api/thermal/power_allocator.rst
590 Documentation/driver-api/thermal/power_allocator.rst
601 Documentation/driver-api/thermal/power_allocator.rst
610 raw readings. It is up to the device driver to determine
618 raw readings. It is up to the device driver to determine
623 Cooling device attributes
624 -------------------------
627 String which represents the type of device, e.g:
629 - for generic ACPI: should be "Fan", "Processor" or "LCD"
630 - for memory controller device on intel_menlow platform:
636 The maximum permissible cooling state of this cooling device.
641 The current cooling state of this cooling device.
644 - cur_state == 0 means no cooling
645 - cur_state == max_state means the maximum cooling.
650 Writing any value resets the cooling device's statistics.
654 The amount of time spent by the cooling device in various cooling
656 will mean this cooling device spent <time> msec of time at <state>.
664 cooling device is changed.
669 This gives fine grained information about all the cooling state
673 reading this will return an -EFBIG error.
685 effectiveness in cooling the thermal zone.
692 |---type: acpitz
693 |---temp: 37000
694 |---mode: enabled
695 |---policy: step_wise
696 |---available_policies: step_wise fair_share
697 |---trip_point_0_temp: 100000
698 |---trip_point_0_type: critical
699 |---trip_point_1_temp: 80000
700 |---trip_point_1_type: passive
701 |---trip_point_2_temp: 70000
702 |---trip_point_2_type: active0
703 |---trip_point_3_temp: 60000
704 |---trip_point_3_type: active1
705 |---cdev0: --->/sys/class/thermal/cooling_device0
706 |---cdev0_trip_point: 1 /* cdev0 can be used for passive */
707 |---cdev0_weight: 1024
708 |---cdev1: --->/sys/class/thermal/cooling_device3
709 |---cdev1_trip_point: 2 /* cdev1 can be used for active[0]*/
710 |---cdev1_weight: 1024
713 |---type: Processor
714 |---max_state: 8
715 |---cur_state: 0
718 |---type: Fan
719 |---max_state: 2
720 |---cur_state: 0
724 |---name: acpitz
725 |---temp1_input: 37000
726 |---temp1_crit: 100000
732 -----------------
741 -------------------------
748 -----------------------------
751 throttling the cooling devices according to the policy configured.
758 ------------------------
760 This function serves as an arbitrator to set the state of a cooling
761 device. It sets the cooling device to the deepest cooling state if
772 queue to fire after a pre-determined number of seconds to start
773 an emergency shutdown of the device using the kernel_power_off()
783 profiled non-zero positive value is a must for emergerncy poweroff to be