projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| ef4c4fdb RM |
1 | Kernel driver k8temp |
| 2 | ==================== | |
| 3 | ||
| 4 | Supported chips: | |
| 0d925626 | 5 | |
| 4660cb35 | 6 | * AMD Athlon64/FX or Opteron CPUs |
| 0d925626 | 7 | |
| ef4c4fdb | 8 | Prefix: 'k8temp' |
| 0d925626 | 9 | |
| ef4c4fdb | 10 | Addresses scanned: PCI space |
| 0d925626 | 11 | |
| 223b2b50 | 12 | Datasheet: http://www.amd.com/system/files/TechDocs/32559.pdf |
| ef4c4fdb RM |
13 | |
| 14 | Author: Rudolf Marek | |
| 0d925626 | 15 | |
| 7188cc66 | 16 | Contact: Rudolf Marek <r.marek@assembler.cz> |
| ef4c4fdb RM |
17 | |
| 18 | Description | |
| 19 | ----------- | |
| 20 | ||
| 4660cb35 RM |
21 | This driver permits reading temperature sensor(s) embedded inside AMD K8 |
| 22 | family CPUs (Athlon64/FX, Opteron). Official documentation says that it works | |
| 23 | from revision F of K8 core, but in fact it seems to be implemented for all | |
| 24 | revisions of K8 except the first two revisions (SH-B0 and SH-B3). | |
| 25 | ||
| 26 | Please note that you will need at least lm-sensors 2.10.1 for proper userspace | |
| 27 | support. | |
| ef4c4fdb RM |
28 | |
| 29 | There can be up to four temperature sensors inside single CPU. The driver | |
| 30 | will auto-detect the sensors and will display only temperatures from | |
| 31 | implemented sensors. | |
| 32 | ||
| 33 | Mapping of /sys files is as follows: | |
| 34 | ||
| 0d925626 MCC |
35 | ============= =================================== |
| 36 | temp1_input temperature of Core 0 and "place" 0 | |
| 37 | temp2_input temperature of Core 0 and "place" 1 | |
| 38 | temp3_input temperature of Core 1 and "place" 0 | |
| 39 | temp4_input temperature of Core 1 and "place" 1 | |
| 40 | ============= =================================== | |
| ef4c4fdb RM |
41 | |
| 42 | Temperatures are measured in degrees Celsius and measurement resolution is | |
| 43 | 1 degree C. It is expected that future CPU will have better resolution. The | |
| 44 | temperature is updated once a second. Valid temperatures are from -49 to | |
| 45 | 206 degrees C. | |
| 46 | ||
| 47 | Temperature known as TCaseMax was specified for processors up to revision E. | |
| 48 | This temperature is defined as temperature between heat-spreader and CPU | |
| 49 | case, so the internal CPU temperature supplied by this driver can be higher. | |
| 50 | There is no easy way how to measure the temperature which will correlate | |
| 51 | with TCaseMax temperature. | |
| 52 | ||
| 53 | For newer revisions of CPU (rev F, socket AM2) there is a mathematically | |
| 54 | computed temperature called TControl, which must be lower than TControlMax. | |
| 55 | ||
| 56 | The relationship is following: | |
| 57 | ||
| 0d925626 | 58 | temp1_input - TjOffset*2 < TControlMax, |
| ef4c4fdb RM |
59 | |
| 60 | TjOffset is not yet exported by the driver, TControlMax is usually | |
| 61 | 70 degrees C. The rule of the thumb -> CPU temperature should not cross | |
| 62 | 60 degrees C too much. |