Commit | Line | Data |
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add77c64 KH |
1 | Kernel driver thmc50 |
2 | ===================== | |
3 | ||
4 | Supported chips: | |
5 | * Analog Devices ADM1022 | |
6 | Prefix: 'adm1022' | |
7 | Addresses scanned: I2C 0x2c - 0x2e | |
8 | Datasheet: http://www.analog.com/en/prod/0,2877,ADM1022,00.html | |
9 | * Texas Instruments THMC50 | |
10 | Prefix: 'thmc50' | |
11 | Addresses scanned: I2C 0x2c - 0x2e | |
0ea6e611 | 12 | Datasheet: http://www.ti.com/ |
add77c64 KH |
13 | |
14 | Author: Krzysztof Helt <krzysztof.h1@wp.pl> | |
15 | ||
16 | This driver was derived from the 2.4 kernel thmc50.c source file. | |
17 | ||
18 | Credits: | |
19 | thmc50.c (2.4 kernel): | |
20 | Frodo Looijaard <frodol@dds.nl> | |
21 | Philip Edelbrock <phil@netroedge.com> | |
22 | ||
23 | Module Parameters | |
24 | ----------------- | |
25 | ||
26 | * adm1022_temp3: short array | |
27 | List of adapter,address pairs to force chips into ADM1022 mode with | |
28 | second remote temperature. This does not work for original THMC50 chips. | |
29 | ||
30 | Description | |
31 | ----------- | |
32 | ||
33 | The THMC50 implements: an internal temperature sensor, support for an | |
34 | external diode-type temperature sensor (compatible w/ the diode sensor inside | |
35 | many processors), and a controllable fan/analog_out DAC. For the temperature | |
36 | sensors, limits can be set through the appropriate Overtemperature Shutdown | |
37 | register and Hysteresis register. Each value can be set and read to half-degree | |
38 | accuracy. An alarm is issued (usually to a connected LM78) when the | |
39 | temperature gets higher then the Overtemperature Shutdown value; it stays on | |
40 | until the temperature falls below the Hysteresis value. All temperatures are in | |
41 | degrees Celsius, and are guaranteed within a range of -55 to +125 degrees. | |
42 | ||
43 | The THMC50 only updates its values each 1.5 seconds; reading it more often | |
44 | will do no harm, but will return 'old' values. | |
45 | ||
46 | The THMC50 is usually used in combination with LM78-like chips, to measure | |
47 | the temperature of the processor(s). | |
48 | ||
49 | The ADM1022 works the same as THMC50 but it is faster (5 Hz instead of | |
50 | 1 Hz for THMC50). It can be also put in a new mode to handle additional | |
51 | remote temperature sensor. The driver use the mode set by BIOS by default. | |
52 | ||
53 | In case the BIOS is broken and the mode is set incorrectly, you can force | |
54 | the mode with additional remote temperature with adm1022_temp3 parameter. | |
55 | A typical symptom of wrong setting is a fan forced to full speed. | |
56 | ||
57 | Driver Features | |
58 | --------------- | |
59 | ||
60 | The driver provides up to three temperatures: | |
61 | ||
62 | temp1 -- internal | |
63 | temp2 -- remote | |
64 | temp3 -- 2nd remote only for ADM1022 | |
65 | ||
66 | pwm1 -- fan speed (0 = stop, 255 = full) | |
67 | pwm1_mode -- always 0 (DC mode) | |
68 | ||
69 | The value of 0 for pwm1 also forces FAN_OFF signal from the chip, | |
70 | so it stops fans even if the value 0 into the ANALOG_OUT register does not. | |
71 | ||
72 | The driver was tested on Compaq AP550 with two ADM1022 chips (one works | |
73 | in the temp3 mode), five temperature readings and two fans. | |
74 |