diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-thermal')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-thermal | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-thermal b/Documentation/ABI/testing/sysfs-class-thermal new file mode 100644 index 000000000..8eee37982 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-thermal @@ -0,0 +1,259 @@ +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 + shouldbe 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 |