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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 | ||
12 | Datasheet: http://focus.ti.com/docs/prod/folders/print/thmc50.html | ||
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 | |||