diff options
author | Jiri Kosina <jkosina@suse.cz> | 2010-08-10 13:22:08 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-08-10 13:22:08 +0200 |
commit | fb8231a8b139035476f2a8aaac837d0099b66dad (patch) | |
tree | 2875806beb96ea0cdab292146767a5085721dc6a /Documentation/hwmon/pkgtemp | |
parent | 426d31071ac476ea62c62656b242930c17b58c00 (diff) | |
parent | f6cec0ae58c17522a7bc4e2f39dae19f199ab534 (diff) |
Merge branch 'master' into for-next
Conflicts:
arch/arm/mach-omap1/board-nokia770.c
Diffstat (limited to 'Documentation/hwmon/pkgtemp')
-rw-r--r-- | Documentation/hwmon/pkgtemp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/hwmon/pkgtemp b/Documentation/hwmon/pkgtemp new file mode 100644 index 00000000000..c8e1fb0fadd --- /dev/null +++ b/Documentation/hwmon/pkgtemp @@ -0,0 +1,36 @@ +Kernel driver pkgtemp +====================== + +Supported chips: + * Intel family + Prefix: 'pkgtemp' + CPUID: + Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual + Volume 3A: System Programming Guide + +Author: Fenghua Yu + +Description +----------- + +This driver permits reading package level temperature sensor embedded inside +Intel CPU package. The sensors can be in core, uncore, memory controller, or +other components in a package. The feature is first implemented in Intel Sandy +Bridge platform. + +Temperature is measured in degrees Celsius and measurement resolution is +1 degree C. Valid temperatures are from 0 to TjMax degrees C, because the actual +value of temperature register is in fact a delta from TjMax. + +Temperature known as TjMax is the maximum junction temperature of package. +We get this from MSR_IA32_TEMPERATURE_TARGET. If the MSR is not accessible, +we define TjMax as 100 degrees Celsius. At this temperature, protection +mechanism will perform actions to forcibly cool down the package. Alarm +may be raised, if the temperature grows enough (more than TjMax) to trigger +the Out-Of-Spec bit. Following table summarizes the exported sysfs files: + +temp1_input - Package temperature (in millidegrees Celsius). +temp1_max - All cooling devices should be turned on. +temp1_crit - Maximum junction temperature (in millidegrees Celsius). +temp1_crit_alarm - Set when Out-of-spec bit is set, never clears. + Correct CPU operation is no longer guaranteed. |