summaryrefslogtreecommitdiff
path: root/Documentation/thermal
diff options
context:
space:
mode:
authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2013-05-18 03:42:03 +0400
committerZhang Rui <rui.zhang@intel.com>2013-06-18 02:27:57 +0400
commit23be63f48d928cd5a21db58f73c731357e895250 (patch)
tree168ea644734f354824d8b97e614b205a70a99f17 /Documentation/thermal
parentf1a18a10566081abfce1649c2f3884b28fff7372 (diff)
downloadlinux-23be63f48d928cd5a21db58f73c731357e895250.tar.xz
Thermal: Documentation for x86 package temperature thermal driver
Added documentation describing details of the x86 package temperature thermal driver. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Diffstat (limited to 'Documentation/thermal')
-rw-r--r--Documentation/thermal/x86_pkg_temperature_thermal47
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/thermal/x86_pkg_temperature_thermal b/Documentation/thermal/x86_pkg_temperature_thermal
new file mode 100644
index 000000000000..17a3a4c0a0ca
--- /dev/null
+++ b/Documentation/thermal/x86_pkg_temperature_thermal
@@ -0,0 +1,47 @@
+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/thermal/sysfs-api.txt" 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
+
+
+
+