aboutsummaryrefslogtreecommitdiff
path: root/Documentation/hwmon/k8temp
diff options
context:
space:
mode:
authorSteven Whitehouse <swhiteho@redhat.com>2006-10-02 08:45:08 -0400
committerSteven Whitehouse <swhiteho@redhat.com>2006-10-02 08:45:08 -0400
commit59458f40e25915a355d8b1d701425fe9f4f9ea23 (patch)
treef1c9a2934df686e36d75f759ab7313b6f0e0e5f9 /Documentation/hwmon/k8temp
parent825f9075d74028d11d7f5932f04e1b5db3022b51 (diff)
parentd834c16516d1ebec4766fc58c059bf01311e6045 (diff)
Merge branch 'master' into gfs2
Diffstat (limited to 'Documentation/hwmon/k8temp')
-rw-r--r--Documentation/hwmon/k8temp52
1 files changed, 52 insertions, 0 deletions
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.