diff options
author | Rudolf Marek <r.marek@assembler.cz> | 2007-05-08 11:22:02 -0400 |
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committer | Jean Delvare <khali@hyperion.delvare> | 2007-05-08 11:22:02 -0400 |
commit | d58ee056cc40117afe4d3bb03006ac537d779634 (patch) | |
tree | 7000aebbc52bf648a98b521e0ba7c745a0fd131e /Documentation/hwmon/coretemp | |
parent | bebe467823c0d8eeb7f49115c255d8a235a20ddb (diff) |
hwmon/coretemp: Add documentation
Documentation for the coretemp driver.
Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'Documentation/hwmon/coretemp')
-rw-r--r-- | Documentation/hwmon/coretemp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/hwmon/coretemp b/Documentation/hwmon/coretemp new file mode 100644 index 000000000000..870cda9416e9 --- /dev/null +++ b/Documentation/hwmon/coretemp | |||
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1 | Kernel driver coretemp | ||
2 | ====================== | ||
3 | |||
4 | Supported chips: | ||
5 | * All Intel Core family | ||
6 | Prefix: 'coretemp' | ||
7 | CPUID: family 0x6, models 0xe, 0xf | ||
8 | Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual | ||
9 | Volume 3A: System Programming Guide | ||
10 | |||
11 | Author: Rudolf Marek | ||
12 | |||
13 | Description | ||
14 | ----------- | ||
15 | |||
16 | This driver permits reading temperature sensor embedded inside Intel Core CPU. | ||
17 | Temperature is measured in degrees Celsius and measurement resolution is | ||
18 | 1 degree C. Valid temperatures are from 0 to TjMax degrees C, because | ||
19 | the actual value of temperature register is in fact a delta from TjMax. | ||
20 | |||
21 | Temperature known as TjMax is the maximum junction temperature of processor. | ||
22 | Intel defines this temperature as 85C or 100C. At this temperature, protection | ||
23 | mechanism will perform actions to forcibly cool down the processor. Alarm | ||
24 | may be raised, if the temperature grows enough (more than TjMax) to trigger | ||
25 | the Out-Of-Spec bit. Following table summarizes the exported sysfs files: | ||
26 | |||
27 | temp1_input - Core temperature (in millidegrees Celsius). | ||
28 | temp1_crit - Maximum junction temperature (in millidegrees Celsius). | ||
29 | temp1_crit_alarm - Set when Out-of-spec bit is set, never clears. | ||
30 | Correct CPU operation is no longer guaranteed. | ||
31 | temp1_label - Contains string "Core X", where X is processor | ||
32 | number. | ||
33 | |||
34 | The TjMax temperature is set to 85 degrees C if undocumented model specific | ||
35 | register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as | ||
36 | (sometimes) documented in processor datasheet. | ||