| Srinivas Pandruvada | 23be63f | 2013-05-17 23:42:03 +0000 | [diff] [blame] | 1 | Kernel driver: x86_pkg_temp_thermal |
| 2 | =================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * x86: with package level thermal management |
| 6 | (Verify using: CPUID.06H:EAX[bit 6] =1) |
| 7 | |
| 8 | Authors: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> |
| 9 | |
| 10 | Reference |
| 11 | --- |
| 12 | Intel® 64 and IA-32 Architectures Software Developer’s Manual (Jan, 2013): |
| 13 | Chapter 14.6: PACKAGE LEVEL THERMAL MANAGEMENT |
| 14 | |
| 15 | Description |
| 16 | --------- |
| 17 | |
| 18 | This driver register CPU digital temperature package level sensor as a thermal |
| 19 | zone with maximum two user mode configurable trip points. Number of trip points |
| 20 | depends on the capability of the package. Once the trip point is violated, |
| 21 | user mode can receive notification via thermal notification mechanism and can |
| 22 | take any action to control temperature. |
| 23 | |
| 24 | |
| 25 | Threshold management |
| 26 | -------------------- |
| 27 | Each package will register as a thermal zone under /sys/class/thermal. |
| 28 | Example: |
| 29 | /sys/class/thermal/thermal_zone1 |
| 30 | |
| 31 | This contains two trip points: |
| 32 | - trip_point_0_temp |
| 33 | - trip_point_1_temp |
| 34 | |
| 35 | User can set any temperature between 0 to TJ-Max temperature. Temperature units |
| 36 | are in milli-degree Celsius. Refer to "Documentation/thermal/sysfs-api.txt" for |
| 37 | thermal sys-fs details. |
| 38 | |
| 39 | Any value other than 0 in these trip points, can trigger thermal notifications. |
| 40 | Setting 0, stops sending thermal notifications. |
| 41 | |
| 42 | Thermal notifications: To get kobject-uevent notifications, set the thermal zone |
| 43 | policy to "user_space". For example: echo -n "user_space" > policy |
| 44 | |
| 45 | |
| 46 | |
| 47 | |