^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) ===================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) Generic Thermal Sysfs driver How To
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) ===================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) Updated: 2 January 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) Copyright (c) 2008 Intel Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 0. Introduction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) ===============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) The generic thermal sysfs provides a set of interfaces for thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) devices (sensors) and thermal cooling devices (fan, processor...) to register
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) with the thermal management solution and to be a part of it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) This how-to focuses on enabling new thermal zone and cooling devices to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) participate in thermal management.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) This solution is platform independent and any type of thermal zone devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) and cooling devices should be able to make use of the infrastructure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) The main task of the thermal sysfs driver is to expose thermal zone attributes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) as well as cooling device attributes to the user space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) An intelligent thermal management application can make decisions based on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) inputs from thermal zone attributes (the current temperature and trip point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) temperature) and throttle appropriate devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) - `[0-*]` denotes any positive number starting from 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) - `[1-*]` denotes any positive number starting from 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 1. thermal sysfs driver interface functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) ===========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 1.1 thermal zone device interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) ---------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) struct thermal_zone_device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) *thermal_zone_device_register(char *type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) int trips, int mask, void *devdata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) struct thermal_zone_device_ops *ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) const struct thermal_zone_params *tzp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) int passive_delay, int polling_delay))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) This interface function adds a new thermal zone device (sensor) to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /sys/class/thermal folder as `thermal_zone[0-*]`. It tries to bind all the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) thermal cooling devices registered at the same time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) type:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) the thermal zone type.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) trips:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) the total number of trip points this thermal zone supports.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) mask:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) Bit string: If 'n'th bit is set, then trip point 'n' is writeable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) devdata:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) device private data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) ops:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) thermal zone device call-backs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) .bind:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) bind the thermal zone device with a thermal cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) .unbind:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) unbind the thermal zone device with a thermal cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) .get_temp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) get the current temperature of the thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) .set_trips:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) set the trip points window. Whenever the current temperature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) is updated, the trip points immediately below and above the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) current temperature are found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) .get_mode:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) get the current mode (enabled/disabled) of the thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) - "enabled" means the kernel thermal management is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) - "disabled" will prevent kernel thermal driver action
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) upon trip points so that user applications can take
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) charge of thermal management.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) .set_mode:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) set the mode (enabled/disabled) of the thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) .get_trip_type:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) get the type of certain trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) .get_trip_temp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) get the temperature above which the certain trip point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) will be fired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) .set_emul_temp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) set the emulation temperature which helps in debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) different threshold temperature points.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) tzp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) thermal zone platform parameters.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) passive_delay:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) number of milliseconds to wait between polls when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) performing passive cooling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) polling_delay:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) number of milliseconds to wait between polls when checking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) whether trip points have been crossed (0 for interrupt driven systems).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) void thermal_zone_device_unregister(struct thermal_zone_device *tz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) This interface function removes the thermal zone device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) It deletes the corresponding entry from /sys/class/thermal folder and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) unbinds all the thermal cooling devices it uses.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) struct thermal_zone_device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) *thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) const struct thermal_zone_of_device_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) This interface adds a new sensor to a DT thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) This function will search the list of thermal zones described in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) device tree and look for the zone that refer to the sensor device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) pointed by dev->of_node as temperature providers. For the zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) pointing to the sensor node, the sensor will be added to the DT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) thermal zone device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) The parameters for this interface are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) dev:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) Device node of sensor containing valid node pointer in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) dev->of_node.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) sensor_id:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) a sensor identifier, in case the sensor IP has more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) than one sensors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) a private pointer (owned by the caller) that will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) passed back, when a temperature reading is needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) ops:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) `struct thermal_zone_of_device_ops *`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) ============== =======================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) get_temp a pointer to a function that reads the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) sensor temperature. This is mandatory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) callback provided by sensor driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) set_trips a pointer to a function that sets a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) temperature window. When this window is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) left the driver must inform the thermal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) core via thermal_zone_device_update.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) get_trend a pointer to a function that reads the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) sensor temperature trend.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) set_emul_temp a pointer to a function that sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) sensor emulated temperature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) ============== =======================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) The thermal zone temperature is provided by the get_temp() function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) pointer of thermal_zone_of_device_ops. When called, it will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) have the private pointer @data back.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) It returns error pointer if fails otherwise valid thermal zone device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) handle. Caller should check the return handle with IS_ERR() for finding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) whether success or not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) void thermal_zone_of_sensor_unregister(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) struct thermal_zone_device *tzd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) This interface unregisters a sensor from a DT thermal zone which was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) successfully added by interface thermal_zone_of_sensor_register().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) This function removes the sensor callbacks and private data from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) thermal zone device registered with thermal_zone_of_sensor_register()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) interface. It will also silent the zone by remove the .get_temp() and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) get_trend() thermal zone device callbacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) struct thermal_zone_device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) *devm_thermal_zone_of_sensor_register(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) int sensor_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) const struct thermal_zone_of_device_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) This interface is resource managed version of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) thermal_zone_of_sensor_register().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) All details of thermal_zone_of_sensor_register() described in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) section 1.1.3 is applicable here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) The benefit of using this interface to register sensor is that it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) is not require to explicitly call thermal_zone_of_sensor_unregister()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) in error path or during driver unbinding as this is done by driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) resource manager.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) void devm_thermal_zone_of_sensor_unregister(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) struct thermal_zone_device *tzd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) This interface is resource managed version of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) thermal_zone_of_sensor_unregister().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) All details of thermal_zone_of_sensor_unregister() described in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) section 1.1.4 is applicable here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) Normally this function will not need to be called and the resource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) management code will ensure that the resource is freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) int thermal_zone_get_slope(struct thermal_zone_device *tz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) This interface is used to read the slope attribute value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) for the thermal zone device, which might be useful for platform
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) drivers for temperature calculations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) int thermal_zone_get_offset(struct thermal_zone_device *tz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) This interface is used to read the offset attribute value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) for the thermal zone device, which might be useful for platform
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) drivers for temperature calculations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 1.2 thermal cooling device interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) ------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) struct thermal_cooling_device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) *thermal_cooling_device_register(char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) void *devdata, struct thermal_cooling_device_ops *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) This interface function adds a new thermal cooling device (fan/processor/...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) to /sys/class/thermal/ folder as `cooling_device[0-*]`. It tries to bind itself
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) to all the thermal zone devices registered at the same time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) name:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) the cooling device name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) devdata:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) device private data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) ops:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) thermal cooling devices call-backs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) .get_max_state:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) get the Maximum throttle state of the cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) .get_cur_state:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) get the Currently requested throttle state of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) .set_cur_state:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) set the Current throttle state of the cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) This interface function removes the thermal cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) It deletes the corresponding entry from /sys/class/thermal folder and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) unbinds itself from all the thermal zone devices using it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 1.3 interface for binding a thermal zone device with a thermal cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) -----------------------------------------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) int trip, struct thermal_cooling_device *cdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) unsigned long upper, unsigned long lower, unsigned int weight);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) This interface function binds a thermal cooling device to a particular trip
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) point of a thermal zone device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) This function is usually called in the thermal zone device .bind callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) tz:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) the thermal zone device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) cdev:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) thermal cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) trip:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) indicates which trip point in this thermal zone the cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) is associated with.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) upper:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) the Maximum cooling state for this trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) THERMAL_NO_LIMIT means no upper limit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) and the cooling device can be in max_state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) lower:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) the Minimum cooling state can be used for this trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) THERMAL_NO_LIMIT means no lower limit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) and the cooling device can be in cooling state 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) weight:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) the influence of this cooling device in this thermal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) zone. See 1.4.1 below for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) int trip, struct thermal_cooling_device *cdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) This interface function unbinds a thermal cooling device from a particular
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) trip point of a thermal zone device. This function is usually called in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) the thermal zone device .unbind callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) tz:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) the thermal zone device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) cdev:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) thermal cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) trip:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) indicates which trip point in this thermal zone the cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) is associated with.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 1.4 Thermal Zone Parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) ---------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) struct thermal_bind_params
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) This structure defines the following parameters that are used to bind
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) a zone with a cooling device for a particular trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) .cdev:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) The cooling device pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) .weight:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) The 'influence' of a particular cooling device on this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) zone. This is relative to the rest of the cooling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) devices. For example, if all cooling devices have a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) weight of 1, then they all contribute the same. You can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) use percentages if you want, but it's not mandatory. A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) weight of 0 means that this cooling device doesn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) contribute to the cooling of this zone unless all cooling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) devices have a weight of 0. If all weights are 0, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) they all contribute the same.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) .trip_mask:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) This is a bit mask that gives the binding relation between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) this thermal zone and cdev, for a particular trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) If nth bit is set, then the cdev and thermal zone are bound
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) for trip point n.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) .binding_limits:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) This is an array of cooling state limits. Must have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) exactly 2 * thermal_zone.number_of_trip_points. It is an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) array consisting of tuples <lower-state upper-state> of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) state limits. Each trip will be associated with one state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) limit tuple when binding. A NULL pointer means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) <THERMAL_NO_LIMITS THERMAL_NO_LIMITS> on all trips.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) These limits are used when binding a cdev to a trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) .match:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) This call back returns success(0) if the 'tz and cdev' need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) be bound, as per platform data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) struct thermal_zone_params
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) This structure defines the platform level parameters for a thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) This data, for each thermal zone should come from the platform layer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) This is an optional feature where some platforms can choose not to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) provide this data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) .governor_name:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) Name of the thermal governor used for this zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) .no_hwmon:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) a boolean to indicate if the thermal to hwmon sysfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) is required. when no_hwmon == false, a hwmon sysfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) will be created. when no_hwmon == true, nothing will be done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) In case the thermal_zone_params is NULL, the hwmon interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) will be created (for backward compatibility).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) .num_tbps:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) Number of thermal_bind_params entries for this zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) .tbp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) thermal_bind_params entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 2. sysfs attributes structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) =============================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) == ================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) RO read only value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) WO write only value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) RW read/write value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) == ================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) Thermal sysfs attributes will be represented under /sys/class/thermal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) Hwmon sysfs I/F extension is also available under /sys/class/hwmon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if hwmon is compiled in or built as a module.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) Thermal zone device sys I/F, created once it's registered::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) /sys/class/thermal/thermal_zone[0-*]:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) |---type: Type of the thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) |---temp: Current temperature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) |---mode: Working mode of the thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) |---policy: Thermal governor used for this zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) |---available_policies: Available thermal governors for this zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) |---trip_point_[0-*]_temp: Trip point temperature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) |---trip_point_[0-*]_type: Trip point type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) |---trip_point_[0-*]_hyst: Hysteresis value for this trip point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) |---emul_temp: Emulated temperature set node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) |---sustainable_power: Sustainable dissipatable power
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) |---k_po: Proportional term during temperature overshoot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) |---k_pu: Proportional term during temperature undershoot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) |---k_i: PID's integral term in the power allocator gov
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) |---k_d: PID's derivative term in the power allocator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) |---integral_cutoff: Offset above which errors are accumulated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) |---slope: Slope constant applied as linear extrapolation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) |---offset: Offset constant applied as linear extrapolation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) Thermal cooling device sys I/F, created once it's registered::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) /sys/class/thermal/cooling_device[0-*]:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) |---type: Type of the cooling device(processor/fan/...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) |---max_state: Maximum cooling state of the cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) |---cur_state: Current cooling state of the cooling device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) |---stats: Directory containing cooling device's statistics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) |---stats/reset: Writing any value resets the statistics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) |---stats/time_in_state_ms: Time (msec) spent in various cooling states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) |---stats/total_trans: Total number of times cooling state is changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) |---stats/trans_table: Cooing state transition table
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) Then next two dynamic attributes are created/removed in pairs. They represent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) the relationship between a thermal zone and its associated cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) They are created/removed for each successful execution of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) /sys/class/thermal/thermal_zone[0-*]:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) |---cdev[0-*]: [0-*]th cooling device in current thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) |---cdev[0-*]_trip_point: Trip point that cdev[0-*] is associated with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) |---cdev[0-*]_weight: Influence of the cooling device in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) this thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) Besides the thermal zone device sysfs I/F and cooling device sysfs I/F,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) the generic thermal driver also creates a hwmon sysfs I/F for each _type_
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) of thermal zone device. E.g. the generic thermal driver registers one hwmon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) class device and build the associated hwmon sysfs I/F for all the registered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) ACPI thermal zones.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) /sys/class/hwmon/hwmon[0-*]:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) |---name: The type of the thermal zone devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) |---temp[1-*]_input: The current temperature of thermal zone [1-*]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) |---temp[1-*]_critical: The critical trip point of thermal zone [1-*]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) Please read Documentation/hwmon/sysfs-interface.rst for additional information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) Thermal zone attributes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) -----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) Strings which represent the thermal zone type.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) This is given by thermal zone driver as part of registration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) E.g: "acpitz" indicates it's an ACPI thermal device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) In order to keep it consistent with hwmon sys attribute; this should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) be a short, lowercase string, not containing spaces nor dashes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) temp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) Current temperature as reported by thermal zone (sensor).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) Unit: millidegree Celsius
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) One of the predefined values in [enabled, disabled].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) This file gives information about the algorithm that is currently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) managing the thermal zone. It can be either default kernel based
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) algorithm or user space application.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) enable Kernel Thermal management.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) Preventing kernel thermal zone driver actions upon
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) trip points so that user application can take full
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) charge of the thermal management.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) policy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) One of the various thermal governors used for a particular zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) RW, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) available_policies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) Available thermal governors which can be used for a particular zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) `trip_point_[0-*]_temp`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) The temperature above which trip point will be fired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) Unit: millidegree Celsius
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) RO, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) `trip_point_[0-*]_type`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) Strings which indicate the type of the trip point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) E.g. it can be one of critical, hot, passive, `active[0-*]` for ACPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) RO, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) `trip_point_[0-*]_hyst`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) The hysteresis value for a trip point, represented as an integer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) Unit: Celsius
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) `cdev[0-*]`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) Sysfs link to the thermal cooling device node where the sys I/F
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) for cooling device throttling control represents.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) RO, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) `cdev[0-*]_trip_point`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) The trip point in this thermal zone which `cdev[0-*]` is associated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) with; -1 means the cooling device is not associated with any trip
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) RO, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) `cdev[0-*]_weight`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) The influence of `cdev[0-*]` in this thermal zone. This value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) is relative to the rest of cooling devices in the thermal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) zone. For example, if a cooling device has a weight double
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) than that of other, it's twice as effective in cooling the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) passive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) Attribute is only present for zones in which the passive cooling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) policy is not supported by native thermal driver. Default is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) and can be set to a temperature (in millidegrees) to enable a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) passive trip point for the zone. Activation is done by polling with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) an interval of 1 second.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) Unit: millidegrees Celsius
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) Valid values: 0 (disabled) or greater than 1000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) emul_temp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) Interface to set the emulated temperature method in thermal zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) (sensor). After setting this temperature, the thermal zone may pass
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) this temperature to platform emulation function if registered or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) cache it locally. This is useful in debugging different temperature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) threshold and its associated cooling action. This is write only node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) and writing 0 on this node should disable emulation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) Unit: millidegree Celsius
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) WO, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) WARNING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) Be careful while enabling this option on production systems,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) because userland can easily disable the thermal policy by simply
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) flooding this sysfs node with low temperature values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) sustainable_power
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) An estimate of the sustained power that can be dissipated by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) the thermal zone. Used by the power allocator governor. For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) more information see Documentation/driver-api/thermal/power_allocator.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) Unit: milliwatts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) k_po
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) The proportional term of the power allocator governor's PID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) controller during temperature overshoot. Temperature overshoot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) is when the current temperature is above the "desired
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) temperature" trip point. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) Documentation/driver-api/thermal/power_allocator.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) k_pu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) The proportional term of the power allocator governor's PID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) controller during temperature undershoot. Temperature undershoot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) is when the current temperature is below the "desired
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) temperature" trip point. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) Documentation/driver-api/thermal/power_allocator.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) k_i
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) The integral term of the power allocator governor's PID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) controller. This term allows the PID controller to compensate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) for long term drift. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) Documentation/driver-api/thermal/power_allocator.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) k_d
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) The derivative term of the power allocator governor's PID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) controller. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) Documentation/driver-api/thermal/power_allocator.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) integral_cutoff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) Temperature offset from the desired temperature trip point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) above which the integral term of the power allocator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) governor's PID controller starts accumulating errors. For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) example, if integral_cutoff is 0, then the integral term only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) accumulates error when temperature is above the desired
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) temperature trip point. For more information see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) Documentation/driver-api/thermal/power_allocator.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) Unit: millidegree Celsius
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) slope
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) The slope constant used in a linear extrapolation model
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) to determine a hotspot temperature based off the sensor's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) raw readings. It is up to the device driver to determine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) the usage of these values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) The offset constant used in a linear extrapolation model
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) to determine a hotspot temperature based off the sensor's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) raw readings. It is up to the device driver to determine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) the usage of these values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) RW, Optional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) Cooling device attributes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) -------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) String which represents the type of device, e.g:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) - for generic ACPI: should be "Fan", "Processor" or "LCD"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) - for memory controller device on intel_menlow platform:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) should be "Memory controller".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) max_state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) The maximum permissible cooling state of this cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) cur_state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) The current cooling state of this cooling device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) The value can any integer numbers between 0 and max_state:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) - cur_state == 0 means no cooling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) - cur_state == max_state means the maximum cooling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) RW, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) stats/reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) Writing any value resets the cooling device's statistics.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) WO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) stats/time_in_state_ms:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) The amount of time spent by the cooling device in various cooling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) states. The output will have "<state> <time>" pair in each line, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) will mean this cooling device spent <time> msec of time at <state>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) Output will have one line for each of the supported states. usertime
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) units here is 10mS (similar to other time exported in /proc).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) stats/total_trans:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) A single positive value showing the total number of times the state of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) cooling device is changed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) stats/trans_table:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) This gives fine grained information about all the cooling state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) transitions. The cat output here is a two dimensional matrix, where an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) entry <i,j> (row i, column j) represents the number of transitions from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) State_i to State_j. If the transition table is bigger than PAGE_SIZE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) reading this will return an -EFBIG error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) RO, Required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) 3. A simple implementation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) ==========================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) ACPI thermal zone may support multiple trip points like critical, hot,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) passive, active. If an ACPI thermal zone supports critical, passive,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) active[0] and active[1] at the same time, it may register itself as a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) thermal_zone_device (thermal_zone1) with 4 trip points in all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) It has one processor and one fan, which are both registered as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) thermal_cooling_device. Both are considered to have the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) effectiveness in cooling the thermal zone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) If the processor is listed in _PSL method, and the fan is listed in _AL0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) method, the sys I/F structure will be built like this::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) /sys/class/thermal:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) |thermal_zone1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) |---type: acpitz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) |---temp: 37000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) |---mode: enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) |---policy: step_wise
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) |---available_policies: step_wise fair_share
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) |---trip_point_0_temp: 100000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) |---trip_point_0_type: critical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) |---trip_point_1_temp: 80000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) |---trip_point_1_type: passive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) |---trip_point_2_temp: 70000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) |---trip_point_2_type: active0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) |---trip_point_3_temp: 60000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) |---trip_point_3_type: active1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) |---cdev0: --->/sys/class/thermal/cooling_device0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) |---cdev0_trip_point: 1 /* cdev0 can be used for passive */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) |---cdev0_weight: 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) |---cdev1: --->/sys/class/thermal/cooling_device3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) |---cdev1_trip_point: 2 /* cdev1 can be used for active[0]*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) |---cdev1_weight: 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) |cooling_device0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) |---type: Processor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) |---max_state: 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) |---cur_state: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) |cooling_device3:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) |---type: Fan
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) |---max_state: 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) |---cur_state: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) /sys/class/hwmon:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) |hwmon0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) |---name: acpitz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) |---temp1_input: 37000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) |---temp1_crit: 100000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) 4. Export Symbol APIs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) =====================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) 4.1. get_tz_trend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) This function returns the trend of a thermal zone, i.e the rate of change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) of temperature of the thermal zone. Ideally, the thermal sensor drivers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) are supposed to implement the callback. If they don't, the thermal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) framework calculated the trend by comparing the previous and the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) temperature values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) 4.2. get_thermal_instance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) -------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) This function returns the thermal_instance corresponding to a given
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) {thermal_zone, cooling_device, trip_point} combination. Returns NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) if such an instance does not exist.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) 4.3. thermal_notify_framework
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) -----------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) This function handles the trip events from sensor drivers. It starts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) throttling the cooling devices according to the policy configured.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) For CRITICAL and HOT trip points, this notifies the respective drivers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) The throttling policy is based on the configured platform data; if no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) platform data is provided, this uses the step_wise throttling policy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) 4.4. thermal_cdev_update
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) ------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) This function serves as an arbitrator to set the state of a cooling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) device. It sets the cooling device to the deepest cooling state if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) 5. thermal_emergency_poweroff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) =============================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) On an event of critical trip temperature crossing. Thermal framework
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) allows the system to shutdown gracefully by calling orderly_poweroff().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) In the event of a failure of orderly_poweroff() to shut down the system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) we are in danger of keeping the system alive at undesirably high
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) temperatures. To mitigate this high risk scenario we program a work
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) queue to fire after a pre-determined number of seconds to start
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) an emergency shutdown of the device using the kernel_power_off()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) function. In case kernel_power_off() fails then finally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) emergency_restart() is called in the worst case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) The delay should be carefully profiled so as to give adequate time for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) orderly_poweroff(). In case of failure of an orderly_poweroff() the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) emergency poweroff kicks in after the delay has elapsed and shuts down
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) If set to 0 emergency poweroff will not be supported. So a carefully
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) profiled non-zero positive value is a must for emergerncy poweroff to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) triggered.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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