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