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Diffstat (limited to 'Documentation/driver-api/thermal/x86_pkg_temperature_thermal.rst')
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diff --git a/Documentation/driver-api/thermal/x86_pkg_temperature_thermal.rst b/Documentation/driver-api/thermal/x86_pkg_temperature_thermal.rst new file mode 100644 index 000000000000..2ac42ccd236f --- /dev/null +++ b/Documentation/driver-api/thermal/x86_pkg_temperature_thermal.rst @@ -0,0 +1,55 @@ +=================================== +Kernel driver: x86_pkg_temp_thermal +=================================== + +Supported chips: + +* x86: with package level thermal management + +(Verify using: CPUID.06H:EAX[bit 6] =1) + +Authors: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> + +Reference +--------- + +Intel® 64 and IA-32 Architectures Software Developer’s Manual (Jan, 2013): +Chapter 14.6: PACKAGE LEVEL THERMAL MANAGEMENT + +Description +----------- + +This driver register CPU digital temperature package level sensor as a thermal +zone with maximum two user mode configurable trip points. Number of trip points +depends on the capability of the package. Once the trip point is violated, +user mode can receive notification via thermal notification mechanism and can +take any action to control temperature. + + +Threshold management +-------------------- +Each package will register as a thermal zone under /sys/class/thermal. + +Example:: + + /sys/class/thermal/thermal_zone1 + +This contains two trip points: + +- trip_point_0_temp +- trip_point_1_temp + +User can set any temperature between 0 to TJ-Max temperature. Temperature units +are in milli-degree Celsius. Refer to "Documentation/driver-api/thermal/sysfs-api.rst" for +thermal sys-fs details. + +Any value other than 0 in these trip points, can trigger thermal notifications. +Setting 0, stops sending thermal notifications. + +Thermal notifications: +To get kobject-uevent notifications, set the thermal zone +policy to "user_space". + +For example:: + + echo -n "user_space" > policy |