Diffstat (limited to 'Documentation/hwmon/k8temp')
1 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/hwmon/k8temp b/Documentation/hwmon/k8temp
new file mode 100644
@@ -0,0 +1,55 @@
+Kernel driver k8temp
+ * 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 <email@example.com>
+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
+There can be up to four temperature sensors inside single CPU. The driver
+will auto-detect the sensors and will display only temperatures from
+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.