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Srinivas Pandruvada23be63f2013-05-17 23:42:03 +00001Kernel driver: x86_pkg_temp_thermal
2===================
3
4Supported chips:
5* x86: with package level thermal management
6(Verify using: CPUID.06H:EAX[bit 6] =1)
7
8Authors: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
9
10Reference
11---
12Intel® 64 and IA-32 Architectures Software Developers Manual (Jan, 2013):
13Chapter 14.6: PACKAGE LEVEL THERMAL MANAGEMENT
14
15Description
16---------
17
18This driver register CPU digital temperature package level sensor as a thermal
19zone with maximum two user mode configurable trip points. Number of trip points
20depends on the capability of the package. Once the trip point is violated,
21user mode can receive notification via thermal notification mechanism and can
22take any action to control temperature.
23
24
25Threshold management
26--------------------
27Each package will register as a thermal zone under /sys/class/thermal.
28Example:
29/sys/class/thermal/thermal_zone1
30
31This contains two trip points:
32- trip_point_0_temp
33- trip_point_1_temp
34
35User can set any temperature between 0 to TJ-Max temperature. Temperature units
36are in milli-degree Celsius. Refer to "Documentation/thermal/sysfs-api.txt" for
37thermal sys-fs details.
38
39Any value other than 0 in these trip points, can trigger thermal notifications.
40Setting 0, stops sending thermal notifications.
41
42Thermal notifications: To get kobject-uevent notifications, set the thermal zone
43policy to "user_space". For example: echo -n "user_space" > policy
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