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Based on kernel version 3.16. Page generated on 2014-08-06 21:39 EST.

1	Kernel driver g760a
2	===================
3	
4	Supported chips:
5	  * Global Mixed-mode Technology Inc. G760A
6	    Prefix: 'g760a'
7	    Datasheet: Publicly available at the GMT website
8	      http://www.gmt.com.tw/product/datasheet/EDS-760A.pdf
9	
10	Author: Herbert Valerio Riedel <hvr@gnu.org>
11	
12	Description
13	-----------
14	
15	The GMT G760A Fan Speed PWM Controller is connected directly to a fan
16	and performs closed-loop control of the fan speed.
17	
18	The fan speed is programmed by setting the period via 'pwm1' of two
19	consecutive speed pulses. The period is defined in terms of clock
20	cycle counts of an assumed 32kHz clock source.
21	
22	Setting a period of 0 stops the fan; setting the period to 255 sets
23	fan to maximum speed.
24	
25	The measured fan rotation speed returned via 'fan1_input' is derived
26	from the measured speed pulse period by assuming again a 32kHz clock
27	source and a 2 pulse-per-revolution fan.
28	
29	The 'alarms' file provides access to the two alarm bits provided by
30	the G760A chip's status register: Bit 0 is set when the actual fan
31	speed differs more than 20% with respect to the programmed fan speed;
32	bit 1 is set when fan speed is below 1920 RPM.
33	
34	The g760a driver will not update its values more frequently than every
35	other second; reading them more often will do no harm, but will return
36	'old' values.
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