projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
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1 | Kernel driver k8temp |
| 2 | ==================== | |
| 3 | ||
| 4 | Supported chips: | |
| 4660cb35 | 5 | * AMD Athlon64/FX or Opteron CPUs |
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6 | Prefix: 'k8temp' |
| 7 | Addresses scanned: PCI space | |
| 0ea6e611 | 8 | Datasheet: http://support.amd.com/us/Processor_TechDocs/32559.pdf |
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9 | |
| 10 | Author: Rudolf Marek | |
| 7188cc66 | 11 | Contact: Rudolf Marek <r.marek@assembler.cz> |
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12 | |
| 13 | Description | |
| 14 | ----------- | |
| 15 | ||
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16 | This driver permits reading temperature sensor(s) embedded inside AMD K8 |
| 17 | family CPUs (Athlon64/FX, Opteron). Official documentation says that it works | |
| 18 | from revision F of K8 core, but in fact it seems to be implemented for all | |
| 19 | revisions of K8 except the first two revisions (SH-B0 and SH-B3). | |
| 20 | ||
| 21 | Please note that you will need at least lm-sensors 2.10.1 for proper userspace | |
| 22 | support. | |
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23 | |
| 24 | There can be up to four temperature sensors inside single CPU. The driver | |
| 25 | will auto-detect the sensors and will display only temperatures from | |
| 26 | implemented sensors. | |
| 27 | ||
| 28 | Mapping of /sys files is as follows: | |
| 29 | ||
| 30 | temp1_input - temperature of Core 0 and "place" 0 | |
| 31 | temp2_input - temperature of Core 0 and "place" 1 | |
| 32 | temp3_input - temperature of Core 1 and "place" 0 | |
| 33 | temp4_input - temperature of Core 1 and "place" 1 | |
| 34 | ||
| 35 | Temperatures are measured in degrees Celsius and measurement resolution is | |
| 36 | 1 degree C. It is expected that future CPU will have better resolution. The | |
| 37 | temperature is updated once a second. Valid temperatures are from -49 to | |
| 38 | 206 degrees C. | |
| 39 | ||
| 40 | Temperature known as TCaseMax was specified for processors up to revision E. | |
| 41 | This temperature is defined as temperature between heat-spreader and CPU | |
| 42 | case, so the internal CPU temperature supplied by this driver can be higher. | |
| 43 | There is no easy way how to measure the temperature which will correlate | |
| 44 | with TCaseMax temperature. | |
| 45 | ||
| 46 | For newer revisions of CPU (rev F, socket AM2) there is a mathematically | |
| 47 | computed temperature called TControl, which must be lower than TControlMax. | |
| 48 | ||
| 49 | The relationship is following: | |
| 50 | ||
| 51 | temp1_input - TjOffset*2 < TControlMax, | |
| 52 | ||
| 53 | TjOffset is not yet exported by the driver, TControlMax is usually | |
| 54 | 70 degrees C. The rule of the thumb -> CPU temperature should not cross | |
| 55 | 60 degrees C too much. |