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| author | Rudolf Marek <r.marek@sh.cvut.cz> | 2006-09-24 20:50:57 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-09-28 15:31:14 -0700 |
| commit | ef4c4fdb2809c84c2ed8f037ae7c96cc03992569 (patch) | |
| tree | 3f370d63afef990567ff0dbaec812c3f06bad3b8 /Documentation/hwmon/k8temp | |
| parent | 360b9ab220aedaf346380fc2344729d9acc3b075 (diff) | |
| download | linux-ef4c4fdb2809c84c2ed8f037ae7c96cc03992569.tar.bz2 | |
k8temp: Add documentation
k8temp: Add documentation
Add promised documentation for the k8temp driver.
Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/hwmon/k8temp')
| -rw-r--r-- | Documentation/hwmon/k8temp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/hwmon/k8temp b/Documentation/hwmon/k8temp new file mode 100644 index 000000000000..bab445ab0f52 --- /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. |