diff options
Diffstat (limited to 'kernel/Documentation/hwmon/k8temp')
| -rw-r--r-- | kernel/Documentation/hwmon/k8temp | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/kernel/Documentation/hwmon/k8temp b/kernel/Documentation/hwmon/k8temp new file mode 100644 index 000000000..716dc24c7 --- /dev/null +++ b/kernel/Documentation/hwmon/k8temp @@ -0,0 +1,55 @@ +Kernel driver k8temp +==================== + +Supported chips: + * AMD Athlon64/FX or Opteron CPUs + Prefix: 'k8temp' + Addresses scanned: PCI space + Datasheet: http://support.amd.com/us/Processor_TechDocs/32559.pdf + +Author: Rudolf Marek +Contact: Rudolf Marek <r.marek@assembler.cz> + +Description +----------- + +This driver permits reading temperature sensor(s) embedded inside AMD K8 +family CPUs (Athlon64/FX, Opteron). 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). + +Please note that you will need at least lm-sensors 2.10.1 for proper userspace +support. + +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. |