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| -rw-r--r-- | Documentation/hwmon/k8temp | 52 |
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diff --git a/Documentation/hwmon/k8temp b/Documentation/hwmon/k8temp new file mode 100644 index 00000000000..bab445ab0f5 --- /dev/null +++ b/Documentation/hwmon/k8temp @@ -0,0 +1,52 @@ +Kernel driver k8temp +==================== + +Supported chips: + * AMD K8 CPU + Prefix: 'k8temp' + Addresses scanned: PCI space + Datasheet: http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32559.pdf + +Author: Rudolf Marek +Contact: Rudolf Marek <r.marek@sh.cvut.cz> + +Description +----------- + +This driver permits reading temperature sensor(s) embedded inside AMD K8 CPUs. +Official documentation says that it works from revision F of K8 core, but +in fact it seems to be implemented for all revisions of K8 except the first +two revisions (SH-B0 and SH-B3). + +There can be up to four temperature sensors inside single CPU. The driver +will auto-detect the sensors and will display only temperatures from +implemented sensors. + +Mapping of /sys files is as follows: + +temp1_input - temperature of Core 0 and "place" 0 +temp2_input - temperature of Core 0 and "place" 1 +temp3_input - temperature of Core 1 and "place" 0 +temp4_input - temperature of Core 1 and "place" 1 + +Temperatures are measured in degrees Celsius and measurement resolution is +1 degree C. It is expected that future CPU will have better resolution. The +temperature is updated once a second. Valid temperatures are from -49 to +206 degrees C. + +Temperature known as TCaseMax was specified for processors up to revision E. +This temperature is defined as temperature between heat-spreader and CPU +case, so the internal CPU temperature supplied by this driver can be higher. +There is no easy way how to measure the temperature which will correlate +with TCaseMax temperature. + +For newer revisions of CPU (rev F, socket AM2) there is a mathematically +computed temperature called TControl, which must be lower than TControlMax. + +The relationship is following: + +temp1_input - TjOffset*2 < TControlMax, + +TjOffset is not yet exported by the driver, TControlMax is usually +70 degrees C. The rule of the thumb -> CPU temperature should not cross +60 degrees C too much. |