What: /sys/class/thermal/thermal_zoneX/type
Description:
Strings which represent the thermal zone type.
This is given by thermal zone driver as part of registration.
E.g: "acpitz" indicates it's an ACPI thermal device.
In order to keep it consistent with hwmon sys attribute; this
should be a short, lowercase string, not containing spaces nor
dashes.
RO, Required
What: /sys/class/thermal/thermal_zoneX/temp
Description:
Current temperature as reported by thermal zone (sensor).
Unit: millidegree Celsius
RO, Required
What: /sys/class/thermal/thermal_zoneX/mode
Description:
One of the predefined values in [enabled, disabled].
This file gives information about the algorithm that is
currently managing the thermal zone. It can be either default
kernel based algorithm or user space application.
enabled
enable Kernel Thermal management.
disabled
Preventing kernel thermal zone driver actions upon
trip points so that user application can take full
charge of the thermal management.
RW, Optional
What: /sys/class/thermal/thermal_zoneX/policy
Description:
One of the various thermal governors used for a particular zone.
RW, Required
What: /sys/class/thermal/thermal_zoneX/available_policies
Description:
Available thermal governors which can be used for a
particular zone.
RO, Required
What: /sys/class/thermal/thermal_zoneX/trip_point_Y_temp
Description:
The temperature above which trip point will be fired.
Unit: millidegree Celsius
RO, Optional
What: /sys/class/thermal/thermal_zoneX/trip_point_Y_type
Description:
Strings which indicate the type of the trip point.
E.g. it can be one of critical, hot, passive, `active[0-*]`
for ACPI thermal zone.
RO, Optional
What: /sys/class/thermal/thermal_zoneX/trip_point_Y_hyst
Description:
The hysteresis value for a trip point, represented as an
integer.
Unit: Celsius
RW, Optional
What: /sys/class/thermal/thermal_zoneX/cdevY
Description:
Sysfs link to the thermal cooling device node where the sys I/F
for cooling device throttling control represents.
RO, Optional
What: /sys/class/thermal/thermal_zoneX/cdevY_trip_point
Description:
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
What: /sys/class/thermal/thermal_zoneX/cdevY_weight
Description:
The influence of `cdev[0-*]` in this thermal zone. This value
is relative to the rest of cooling devices in the thermal
zone. For example, if a cooling device has a weight double
than that of other, it's twice as effective in cooling the
thermal zone.
RW, Optional
What: /sys/class/thermal/thermal_zoneX/emul_temp
Description:
Interface to set the emulated temperature method in thermal zone
(sensor). After setting this temperature, the thermal zone may
pass this temperature to platform emulation function if
registered or cache it locally. This is useful in debugging
different temperature threshold and its associated cooling
action. This is write only node and writing 0 on this node
should disable emulation.
Unit: millidegree Celsius
WO, Optional
WARNING:
Be careful while enabling this option on production systems,
because userland can easily disable the thermal policy by simply
flooding this sysfs node with low temperature values.
What: /sys/class/thermal/thermal_zoneX/k_d
Description:
The derivative term of the power allocator governor's PID
controller. For more information see
Documentation/driver-api/thermal/power_allocator.rst
RW, Optional
What: /sys/class/thermal/thermal_zoneX/k_i
Description:
The integral term of the power allocator governor's PID
controller. This term allows the PID controller to compensate
for long term drift. For more information see
Documentation/driver-api/thermal/power_allocator.rst
RW, Optional
What: /sys/class/thermal/thermal_zoneX/k_po
Description:
The proportional term of the power allocator governor's PID
controller during temperature overshoot. Temperature overshoot
is when the current temperature is above the "desired
temperature" trip point. For more information see
Documentation/driver-api/thermal/power_allocator.rst
RW, Optional
What: /sys/class/thermal/thermal_zoneX/k_pu
Description:
The proportional term of the power allocator governor's PID
controller during temperature undershoot. Temperature undershoot
is when the current temperature is below the "desired
temperature" trip point. For more information see
Documentation/driver-api/thermal/power_allocator.rst
RW, Optional
What: /sys/class/thermal/thermal_zoneX/integral_cutoff
Description:
Temperature offset from the desired temperature trip point
above which the integral term of the power allocator
governor's PID controller starts accumulating errors. For
example, if integral_cutoff is 0, then the integral term only
accumulates error when temperature is above the desired
temperature trip point. For more information see
Documentation/driver-api/thermal/power_allocator.rst
Unit: millidegree Celsius
RW, Optional
What: /sys/class/thermal/thermal_zoneX/slope
Description:
The slope constant used in a linear extrapolation model
to determine a hotspot temperature based off the sensor's
raw readings. It is up to the device driver to determine
the usage of these values.
RW, Optional
What: /sys/class/thermal/thermal_zoneX/offset
Description:
The offset constant used in a linear extrapolation model
to determine a hotspot temperature based off the sensor's
raw readings. It is up to the device driver to determine
the usage of these values.
RW, Optional
What: /sys/class/thermal/thermal_zoneX/sustainable_power
Description:
An estimate of the sustained power that can be dissipated by
the thermal zone. Used by the power allocator governor. For
more information see
Documentation/driver-api/thermal/power_allocator.rst
Unit: milliwatts
RW, Optional
What: /sys/class/thermal/cooling_deviceX/type
Description:
String which represents the type of device, e.g:
- for generic ACPI: should be "Fan", "Processor" or "LCD"
- for memory controller device on intel_menlow platform:
should be "Memory controller".
RO, Required
What: /sys/class/thermal/cooling_deviceX/max_state
Description:
The maximum permissible cooling state of this cooling device.
RO, Required
What: /sys/class/thermal/cooling_deviceX/cur_state
Description:
The current cooling state of this cooling device.
The value can any integer numbers between 0 and max_state:
- cur_state == 0 means no cooling
- cur_state == max_state means the maximum cooling.
RW, Required
What: /sys/class/thermal/cooling_deviceX/stats/reset
Description:
Writing any value resets the cooling device's statistics.
WO, Required
What: /sys/class/thermal/cooling_deviceX/stats/time_in_state_ms:
Description:
The amount of time spent by the cooling device in various
cooling states. The output will have "<state> <time>" pair
in each line, which will mean this cooling device spent <time>
msec of time at <state>.
Output will have one line for each of the supported states.
RO, Required
What: /sys/class/thermal/cooling_deviceX/stats/total_trans
Description:
A single positive value showing the total number of times
the state of a cooling device is changed.
RO, Required
What: /sys/class/thermal/cooling_deviceX/stats/trans_table
Description:
This gives fine grained information about all the cooling state
transitions. The cat output here is a two dimensional matrix,
where an entry <i,j> (row i, column j) represents the number
of transitions from State_i to State_j. If the transition
table is bigger than PAGE_SIZE, reading this will return
an -EFBIG error.
RO, Required
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