0001 What: /sys/class/thermal/thermal_zoneX/type
0002 Description:
0003 Strings which represent the thermal zone type.
0004 This is given by thermal zone driver as part of registration.
0005 E.g: "acpitz" indicates it's an ACPI thermal device.
0006 In order to keep it consistent with hwmon sys attribute; this
0007 shouldbe a short, lowercase string, not containing spaces nor
0008 dashes.
0009
0010 RO, Required
0011
0012 What: /sys/class/thermal/thermal_zoneX/temp
0013 Description:
0014 Current temperature as reported by thermal zone (sensor).
0015
0016 Unit: millidegree Celsius
0017
0018 RO, Required
0019
0020 What: /sys/class/thermal/thermal_zoneX/mode
0021 Description:
0022 One of the predefined values in [enabled, disabled].
0023 This file gives information about the algorithm that is
0024 currently managing the thermal zone. It can be either default
0025 kernel based algorithm or user space application.
0026
0027 enabled
0028 enable Kernel Thermal management.
0029 disabled
0030 Preventing kernel thermal zone driver actions upon
0031 trip points so that user application can take full
0032 charge of the thermal management.
0033
0034 RW, Optional
0035
0036 What: /sys/class/thermal/thermal_zoneX/policy
0037 Description:
0038 One of the various thermal governors used for a particular zone.
0039
0040 RW, Required
0041
0042 What: /sys/class/thermal/thermal_zoneX/available_policies
0043 Description:
0044 Available thermal governors which can be used for a
0045 particular zone.
0046
0047 RO, Required
0048
0049 What: /sys/class/thermal/thermal_zoneX/trip_point_Y_temp
0050 Description:
0051 The temperature above which trip point will be fired.
0052
0053 Unit: millidegree Celsius
0054
0055 RO, Optional
0056
0057 What: /sys/class/thermal/thermal_zoneX/trip_point_Y_type
0058 Description:
0059 Strings which indicate the type of the trip point.
0060
0061 E.g. it can be one of critical, hot, passive, `active[0-*]`
0062 for ACPI thermal zone.
0063
0064 RO, Optional
0065
0066 What: /sys/class/thermal/thermal_zoneX/trip_point_Y_hyst
0067 Description:
0068 The hysteresis value for a trip point, represented as an
0069 integer.
0070
0071 Unit: Celsius
0072
0073 RW, Optional
0074
0075 What: /sys/class/thermal/thermal_zoneX/cdevY
0076 Description:
0077 Sysfs link to the thermal cooling device node where the sys I/F
0078 for cooling device throttling control represents.
0079
0080 RO, Optional
0081
0082 What: /sys/class/thermal/thermal_zoneX/cdevY_trip_point
0083 Description:
0084 The trip point in this thermal zone which `cdev[0-*]` is
0085 associated with; -1 means the cooling device is not
0086 associated with any trip point.
0087
0088 RO, Optional
0089
0090 What: /sys/class/thermal/thermal_zoneX/cdevY_weight
0091 Description:
0092 The influence of `cdev[0-*]` in this thermal zone. This value
0093 is relative to the rest of cooling devices in the thermal
0094 zone. For example, if a cooling device has a weight double
0095 than that of other, it's twice as effective in cooling the
0096 thermal zone.
0097
0098 RW, Optional
0099
0100 What: /sys/class/thermal/thermal_zoneX/emul_temp
0101 Description:
0102 Interface to set the emulated temperature method in thermal zone
0103 (sensor). After setting this temperature, the thermal zone may
0104 pass this temperature to platform emulation function if
0105 registered or cache it locally. This is useful in debugging
0106 different temperature threshold and its associated cooling
0107 action. This is write only node and writing 0 on this node
0108 should disable emulation.
0109
0110 Unit: millidegree Celsius
0111
0112 WO, Optional
0113
0114 WARNING:
0115 Be careful while enabling this option on production systems,
0116 because userland can easily disable the thermal policy by simply
0117 flooding this sysfs node with low temperature values.
0118
0119
0120 What: /sys/class/thermal/thermal_zoneX/k_d
0121 Description:
0122 The derivative term of the power allocator governor's PID
0123 controller. For more information see
0124 Documentation/driver-api/thermal/power_allocator.rst
0125
0126 RW, Optional
0127
0128 What: /sys/class/thermal/thermal_zoneX/k_i
0129 Description:
0130 The integral term of the power allocator governor's PID
0131 controller. This term allows the PID controller to compensate
0132 for long term drift. For more information see
0133 Documentation/driver-api/thermal/power_allocator.rst
0134
0135 RW, Optional
0136
0137 What: /sys/class/thermal/thermal_zoneX/k_po
0138 Description:
0139 The proportional term of the power allocator governor's PID
0140 controller during temperature overshoot. Temperature overshoot
0141 is when the current temperature is above the "desired
0142 temperature" trip point. For more information see
0143 Documentation/driver-api/thermal/power_allocator.rst
0144
0145 RW, Optional
0146
0147 What: /sys/class/thermal/thermal_zoneX/k_pu
0148 Description:
0149 The proportional term of the power allocator governor's PID
0150 controller during temperature undershoot. Temperature undershoot
0151 is when the current temperature is below the "desired
0152 temperature" trip point. For more information see
0153 Documentation/driver-api/thermal/power_allocator.rst
0154
0155 RW, Optional
0156
0157 What: /sys/class/thermal/thermal_zoneX/integral_cutoff
0158 Description:
0159 Temperature offset from the desired temperature trip point
0160 above which the integral term of the power allocator
0161 governor's PID controller starts accumulating errors. For
0162 example, if integral_cutoff is 0, then the integral term only
0163 accumulates error when temperature is above the desired
0164 temperature trip point. For more information see
0165 Documentation/driver-api/thermal/power_allocator.rst
0166
0167 Unit: millidegree Celsius
0168
0169 RW, Optional
0170
0171 What: /sys/class/thermal/thermal_zoneX/slope
0172 Description:
0173 The slope constant used in a linear extrapolation model
0174 to determine a hotspot temperature based off the sensor's
0175 raw readings. It is up to the device driver to determine
0176 the usage of these values.
0177
0178 RW, Optional
0179
0180 What: /sys/class/thermal/thermal_zoneX/offset
0181 Description:
0182 The offset constant used in a linear extrapolation model
0183 to determine a hotspot temperature based off the sensor's
0184 raw readings. It is up to the device driver to determine
0185 the usage of these values.
0186
0187 RW, Optional
0188
0189 What: /sys/class/thermal/thermal_zoneX/sustainable_power
0190 Description:
0191 An estimate of the sustained power that can be dissipated by
0192 the thermal zone. Used by the power allocator governor. For
0193 more information see
0194 Documentation/driver-api/thermal/power_allocator.rst
0195
0196 Unit: milliwatts
0197
0198 RW, Optional
0199
0200 What: /sys/class/thermal/cooling_deviceX/type
0201 Description:
0202 String which represents the type of device, e.g:
0203
0204 - for generic ACPI: should be "Fan", "Processor" or "LCD"
0205 - for memory controller device on intel_menlow platform:
0206 should be "Memory controller".
0207
0208 RO, Required
0209
0210 What: /sys/class/thermal/cooling_deviceX/max_state
0211 Description:
0212 The maximum permissible cooling state of this cooling device.
0213
0214 RO, Required
0215
0216 What: /sys/class/thermal/cooling_deviceX/cur_state
0217 Description:
0218 The current cooling state of this cooling device.
0219 The value can any integer numbers between 0 and max_state:
0220
0221 - cur_state == 0 means no cooling
0222 - cur_state == max_state means the maximum cooling.
0223
0224 RW, Required
0225
0226 What: /sys/class/thermal/cooling_deviceX/stats/reset
0227 Description:
0228 Writing any value resets the cooling device's statistics.
0229
0230 WO, Required
0231
0232 What: /sys/class/thermal/cooling_deviceX/stats/time_in_state_ms:
0233 Description:
0234 The amount of time spent by the cooling device in various
0235 cooling states. The output will have "<state> <time>" pair
0236 in each line, which will mean this cooling device spent <time>
0237 msec of time at <state>.
0238
0239 Output will have one line for each of the supported states.
0240
0241 RO, Required
0242
0243 What: /sys/class/thermal/cooling_deviceX/stats/total_trans
0244 Description:
0245 A single positive value showing the total number of times
0246 the state of a cooling device is changed.
0247
0248 RO, Required
0249
0250 What: /sys/class/thermal/cooling_deviceX/stats/trans_table
0251 Description:
0252 This gives fine grained information about all the cooling state
0253 transitions. The cat output here is a two dimensional matrix,
0254 where an entry <i,j> (row i, column j) represents the number
0255 of transitions from State_i to State_j. If the transition
0256 table is bigger than PAGE_SIZE, reading this will return
0257 an -EFBIG error.
0258
0259 RO, Required
