About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / hwmon / thmc50




Custom Search

Based on kernel version 3.13. Page generated on 2014-01-20 22:03 EST.

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://www.ti.com/ 
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.
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.