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Diffstat (limited to 'Documentation/driver-api/thermal/sysfs-api.rst')
| -rw-r--r-- | Documentation/driver-api/thermal/sysfs-api.rst | 225 |
1 files changed, 3 insertions, 222 deletions
diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index c93fa5e961a0..2e0f79a9e2ee 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -428,6 +428,9 @@ of thermal zone device. E.g. the generic thermal driver registers one hwmon class device and build the associated hwmon sysfs I/F for all the registered ACPI thermal zones. +Please read Documentation/ABI/testing/sysfs-class-thermal for thermal +zone and cooling device attribute details. + :: /sys/class/hwmon/hwmon[0-*]: @@ -437,228 +440,6 @@ ACPI thermal zones. Please read Documentation/hwmon/sysfs-interface.rst for additional information. -Thermal zone attributes ------------------------ - -type - 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 - -temp - Current temperature as reported by thermal zone (sensor). - Unit: millidegree Celsius - RO, Required - -mode - 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 - -policy - One of the various thermal governors used for a particular zone. - - RW, Required - -available_policies - Available thermal governors which can be used for a particular zone. - - RO, Required - -`trip_point_[0-*]_temp` - The temperature above which trip point will be fired. - - Unit: millidegree Celsius - - RO, Optional - -`trip_point_[0-*]_type` - 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 - -`trip_point_[0-*]_hyst` - The hysteresis value for a trip point, represented as an integer - Unit: Celsius - RW, Optional - -`cdev[0-*]` - Sysfs link to the thermal cooling device node where the sys I/F - for cooling device throttling control represents. - - RO, Optional - -`cdev[0-*]_trip_point` - 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 - -`cdev[0-*]_weight` - 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 - -emul_temp - 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. - -sustainable_power - 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 - -k_po - 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 - -k_pu - 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 - -k_i - 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 - -k_d - The derivative term of the power allocator governor's PID - controller. For more information see - Documentation/driver-api/thermal/power_allocator.rst - - RW, Optional - -integral_cutoff - 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 - -slope - 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 - -offset - 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 - -Cooling device attributes -------------------------- - -type - 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 - -max_state - The maximum permissible cooling state of this cooling device. - - RO, Required - -cur_state - 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 - -stats/reset - Writing any value resets the cooling device's statistics. - WO, Required - -stats/time_in_state_ms: - 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 - - -stats/total_trans: - A single positive value showing the total number of times the state of a - cooling device is changed. - - RO, Required - -stats/trans_table: - 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 - 3. A simple implementation ========================== |