sysfs-class-thermal (7932B)
1What: /sys/class/thermal/thermal_zoneX/type 2Description: 3 Strings which represent the thermal zone type. 4 This is given by thermal zone driver as part of registration. 5 E.g: "acpitz" indicates it's an ACPI thermal device. 6 In order to keep it consistent with hwmon sys attribute; this 7 shouldbe a short, lowercase string, not containing spaces nor 8 dashes. 9 10 RO, Required 11 12What: /sys/class/thermal/thermal_zoneX/temp 13Description: 14 Current temperature as reported by thermal zone (sensor). 15 16 Unit: millidegree Celsius 17 18 RO, Required 19 20What: /sys/class/thermal/thermal_zoneX/mode 21Description: 22 One of the predefined values in [enabled, disabled]. 23 This file gives information about the algorithm that is 24 currently managing the thermal zone. It can be either default 25 kernel based algorithm or user space application. 26 27 enabled 28 enable Kernel Thermal management. 29 disabled 30 Preventing kernel thermal zone driver actions upon 31 trip points so that user application can take full 32 charge of the thermal management. 33 34 RW, Optional 35 36What: /sys/class/thermal/thermal_zoneX/policy 37Description: 38 One of the various thermal governors used for a particular zone. 39 40 RW, Required 41 42What: /sys/class/thermal/thermal_zoneX/available_policies 43Description: 44 Available thermal governors which can be used for a 45 particular zone. 46 47 RO, Required 48 49What: /sys/class/thermal/thermal_zoneX/trip_point_Y_temp 50Description: 51 The temperature above which trip point will be fired. 52 53 Unit: millidegree Celsius 54 55 RO, Optional 56 57What: /sys/class/thermal/thermal_zoneX/trip_point_Y_type 58Description: 59 Strings which indicate the type of the trip point. 60 61 E.g. it can be one of critical, hot, passive, `active[0-*]` 62 for ACPI thermal zone. 63 64 RO, Optional 65 66What: /sys/class/thermal/thermal_zoneX/trip_point_Y_hyst 67Description: 68 The hysteresis value for a trip point, represented as an 69 integer. 70 71 Unit: Celsius 72 73 RW, Optional 74 75What: /sys/class/thermal/thermal_zoneX/cdevY 76Description: 77 Sysfs link to the thermal cooling device node where the sys I/F 78 for cooling device throttling control represents. 79 80 RO, Optional 81 82What: /sys/class/thermal/thermal_zoneX/cdevY_trip_point 83Description: 84 The trip point in this thermal zone which `cdev[0-*]` is 85 associated with; -1 means the cooling device is not 86 associated with any trip point. 87 88 RO, Optional 89 90What: /sys/class/thermal/thermal_zoneX/cdevY_weight 91Description: 92 The influence of `cdev[0-*]` in this thermal zone. This value 93 is relative to the rest of cooling devices in the thermal 94 zone. For example, if a cooling device has a weight double 95 than that of other, it's twice as effective in cooling the 96 thermal zone. 97 98 RW, Optional 99 100What: /sys/class/thermal/thermal_zoneX/emul_temp 101Description: 102 Interface to set the emulated temperature method in thermal zone 103 (sensor). After setting this temperature, the thermal zone may 104 pass this temperature to platform emulation function if 105 registered or cache it locally. This is useful in debugging 106 different temperature threshold and its associated cooling 107 action. This is write only node and writing 0 on this node 108 should disable emulation. 109 110 Unit: millidegree Celsius 111 112 WO, Optional 113 114 WARNING: 115 Be careful while enabling this option on production systems, 116 because userland can easily disable the thermal policy by simply 117 flooding this sysfs node with low temperature values. 118 119 120What: /sys/class/thermal/thermal_zoneX/k_d 121Description: 122 The derivative term of the power allocator governor's PID 123 controller. For more information see 124 Documentation/driver-api/thermal/power_allocator.rst 125 126 RW, Optional 127 128What: /sys/class/thermal/thermal_zoneX/k_i 129Description: 130 The integral term of the power allocator governor's PID 131 controller. This term allows the PID controller to compensate 132 for long term drift. For more information see 133 Documentation/driver-api/thermal/power_allocator.rst 134 135 RW, Optional 136 137What: /sys/class/thermal/thermal_zoneX/k_po 138Description: 139 The proportional term of the power allocator governor's PID 140 controller during temperature overshoot. Temperature overshoot 141 is when the current temperature is above the "desired 142 temperature" trip point. For more information see 143 Documentation/driver-api/thermal/power_allocator.rst 144 145 RW, Optional 146 147What: /sys/class/thermal/thermal_zoneX/k_pu 148Description: 149 The proportional term of the power allocator governor's PID 150 controller during temperature undershoot. Temperature undershoot 151 is when the current temperature is below the "desired 152 temperature" trip point. For more information see 153 Documentation/driver-api/thermal/power_allocator.rst 154 155 RW, Optional 156 157What: /sys/class/thermal/thermal_zoneX/integral_cutoff 158Description: 159 Temperature offset from the desired temperature trip point 160 above which the integral term of the power allocator 161 governor's PID controller starts accumulating errors. For 162 example, if integral_cutoff is 0, then the integral term only 163 accumulates error when temperature is above the desired 164 temperature trip point. For more information see 165 Documentation/driver-api/thermal/power_allocator.rst 166 167 Unit: millidegree Celsius 168 169 RW, Optional 170 171What: /sys/class/thermal/thermal_zoneX/slope 172Description: 173 The slope constant used in a linear extrapolation model 174 to determine a hotspot temperature based off the sensor's 175 raw readings. It is up to the device driver to determine 176 the usage of these values. 177 178 RW, Optional 179 180What: /sys/class/thermal/thermal_zoneX/offset 181Description: 182 The offset constant used in a linear extrapolation model 183 to determine a hotspot temperature based off the sensor's 184 raw readings. It is up to the device driver to determine 185 the usage of these values. 186 187 RW, Optional 188 189What: /sys/class/thermal/thermal_zoneX/sustainable_power 190Description: 191 An estimate of the sustained power that can be dissipated by 192 the thermal zone. Used by the power allocator governor. For 193 more information see 194 Documentation/driver-api/thermal/power_allocator.rst 195 196 Unit: milliwatts 197 198 RW, Optional 199 200What: /sys/class/thermal/cooling_deviceX/type 201Description: 202 String which represents the type of device, e.g: 203 204 - for generic ACPI: should be "Fan", "Processor" or "LCD" 205 - for memory controller device on intel_menlow platform: 206 should be "Memory controller". 207 208 RO, Required 209 210What: /sys/class/thermal/cooling_deviceX/max_state 211Description: 212 The maximum permissible cooling state of this cooling device. 213 214 RO, Required 215 216What: /sys/class/thermal/cooling_deviceX/cur_state 217Description: 218 The current cooling state of this cooling device. 219 The value can any integer numbers between 0 and max_state: 220 221 - cur_state == 0 means no cooling 222 - cur_state == max_state means the maximum cooling. 223 224 RW, Required 225 226What: /sys/class/thermal/cooling_deviceX/stats/reset 227Description: 228 Writing any value resets the cooling device's statistics. 229 230 WO, Required 231 232What: /sys/class/thermal/cooling_deviceX/stats/time_in_state_ms: 233Description: 234 The amount of time spent by the cooling device in various 235 cooling states. The output will have "<state> <time>" pair 236 in each line, which will mean this cooling device spent <time> 237 msec of time at <state>. 238 239 Output will have one line for each of the supported states. 240 241 RO, Required 242 243What: /sys/class/thermal/cooling_deviceX/stats/total_trans 244Description: 245 A single positive value showing the total number of times 246 the state of a cooling device is changed. 247 248 RO, Required 249 250What: /sys/class/thermal/cooling_deviceX/stats/trans_table 251Description: 252 This gives fine grained information about all the cooling state 253 transitions. The cat output here is a two dimensional matrix, 254 where an entry <i,j> (row i, column j) represents the number 255 of transitions from State_i to State_j. If the transition 256 table is bigger than PAGE_SIZE, reading this will return 257 an -EFBIG error. 258 259 RO, Required