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Based on kernel version 2.6.33. Page generated on 2010-02-24 15:36 EST.

1	Kernel driver it87
2	==================
3	
4	Supported chips:
5	  * IT8705F
6	    Prefix: 'it87'
7	    Addresses scanned: from Super I/O config space (8 I/O ports)
8	    Datasheet: Publicly available at the ITE website
9	               http://www.ite.com.tw/product_info/file/pc/IT8705F_V.0.4.1.pdf
10	  * IT8712F
11	    Prefix: 'it8712'
12	    Addresses scanned: from Super I/O config space (8 I/O ports)
13	    Datasheet: Publicly available at the ITE website
14	               http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.1.pdf
15	               http://www.ite.com.tw/product_info/file/pc/Errata%20V0.1%20for%20IT8712F%20V0.9.1.pdf
16	               http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.3.pdf
17	  * IT8716F/IT8726F
18	    Prefix: 'it8716'
19	    Addresses scanned: from Super I/O config space (8 I/O ports)
20	    Datasheet: Publicly available at the ITE website
21	               http://www.ite.com.tw/product_info/file/pc/IT8716F_V0.3.ZIP
22	               http://www.ite.com.tw/product_info/file/pc/IT8726F_V0.3.pdf
23	  * IT8718F
24	    Prefix: 'it8718'
25	    Addresses scanned: from Super I/O config space (8 I/O ports)
26	    Datasheet: Publicly available at the ITE website
27	               http://www.ite.com.tw/product_info/file/pc/IT8718F_V0.2.zip
28	               http://www.ite.com.tw/product_info/file/pc/IT8718F_V0%203_(for%20C%20version).zip
29	  * IT8720F
30	    Prefix: 'it8720'
31	    Addresses scanned: from Super I/O config space (8 I/O ports)
32	    Datasheet: Not yet publicly available.
33	  * SiS950   [clone of IT8705F]
34	    Prefix: 'it87'
35	    Addresses scanned: from Super I/O config space (8 I/O ports)
36	    Datasheet: No longer be available
37	
38	Authors:
39	    Christophe Gauthron
40	    Jean Delvare <khali[AT]linux-fr[DOT]org>
41	
42	
43	Module Parameters
44	-----------------
45	
46	* update_vbat: int
47	
48	  0 if vbat should report power on value, 1 if vbat should be updated after
49	  each read. Default is 0. On some boards the battery voltage is provided
50	  by either the battery or the onboard power supply. Only the first reading
51	  at power on will be the actual battery voltage (which the chip does
52	  automatically). On other boards the battery voltage is always fed to
53	  the chip so can be read at any time. Excessive reading may decrease
54	  battery life but no information is given in the datasheet.
55	
56	* fix_pwm_polarity int
57	
58	  Force PWM polarity to active high (DANGEROUS). Some chips are
59	  misconfigured by BIOS - PWM values would be inverted. This option tries
60	  to fix this. Please contact your BIOS manufacturer and ask him for fix.
61	
62	
63	Hardware Interfaces
64	-------------------
65	
66	All the chips suported by this driver are LPC Super-I/O chips, accessed
67	through the LPC bus (ISA-like I/O ports). The IT8712F additionally has an
68	SMBus interface to the hardware monitoring functions. This driver no
69	longer supports this interface though, as it is slower and less reliable
70	than the ISA access, and was only available on a small number of
71	motherboard models.
72	
73	
74	Description
75	-----------
76	
77	This driver implements support for the IT8705F, IT8712F, IT8716F,
78	IT8718F, IT8720F, IT8726F and SiS950 chips.
79	
80	These chips are 'Super I/O chips', supporting floppy disks, infrared ports,
81	joysticks and other miscellaneous stuff. For hardware monitoring, they
82	include an 'environment controller' with 3 temperature sensors, 3 fan
83	rotation speed sensors, 8 voltage sensors, and associated alarms.
84	
85	The IT8712F and IT8716F additionally feature VID inputs, used to report
86	the Vcore voltage of the processor. The early IT8712F have 5 VID pins,
87	the IT8716F and late IT8712F have 6. They are shared with other functions
88	though, so the functionality may not be available on a given system.
89	
90	The IT8718F and IT8720F also features VID inputs (up to 8 pins) but the value
91	is stored in the Super-I/O configuration space. Due to technical limitations,
92	this value can currently only be read once at initialization time, so
93	the driver won't notice and report changes in the VID value. The two
94	upper VID bits share their pins with voltage inputs (in5 and in6) so you
95	can't have both on a given board.
96	
97	The IT8716F, IT8718F, IT8720F and later IT8712F revisions have support for
98	2 additional fans. The additional fans are supported by the driver.
99	
100	The IT8716F, IT8718F and IT8720F, and late IT8712F and IT8705F also have
101	optional 16-bit tachometer counters for fans 1 to 3. This is better (no more
102	fan clock divider mess) but not compatible with the older chips and
103	revisions. The 16-bit tachometer mode is enabled by the driver when one
104	of the above chips is detected.
105	
106	The IT8726F is just bit enhanced IT8716F with additional hardware
107	for AMD power sequencing. Therefore the chip will appear as IT8716F
108	to userspace applications.
109	
110	Temperatures are measured in degrees Celsius. An alarm is triggered once
111	when the Overtemperature Shutdown limit is crossed.
112	
113	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
114	triggered if the rotation speed has dropped below a programmable limit. When
115	16-bit tachometer counters aren't used, fan readings can be divided by
116	a programmable divider (1, 2, 4 or 8) to give the readings more range or
117	accuracy. With a divider of 2, the lowest representable value is around
118	2600 RPM. Not all RPM values can accurately be represented, so some rounding
119	is done.
120	
121	Voltage sensors (also known as IN sensors) report their values in volts. An
122	alarm is triggered if the voltage has crossed a programmable minimum or
123	maximum limit. Note that minimum in this case always means 'closest to
124	zero'; this is important for negative voltage measurements. All voltage
125	inputs can measure voltages between 0 and 4.08 volts, with a resolution of
126	0.016 volt. The battery voltage in8 does not have limit registers.
127	
128	The VID lines (IT8712F/IT8716F/IT8718F/IT8720F) encode the core voltage value:
129	the voltage level your processor should work with. This is hardcoded by
130	the mainboard and/or processor itself. It is a value in volts.
131	
132	If an alarm triggers, it will remain triggered until the hardware register
133	is read at least once. This means that the cause for the alarm may already
134	have disappeared! Note that in the current implementation, all hardware
135	registers are read whenever any data is read (unless it is less than 1.5
136	seconds since the last update). This means that you can easily miss
137	once-only alarms.
138	
139	The IT87xx only updates its values each 1.5 seconds; reading it more often
140	will do no harm, but will return 'old' values.
141	
142	To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2,
143	or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
144	Give 0 for unused sensor. Any other value is invalid. To configure this at
145	startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor;
146	3 = thermal diode)
147	
148	
149	Fan speed control
150	-----------------
151	
152	The fan speed control features are limited to manual PWM mode. Automatic
153	"Smart Guardian" mode control handling is not implemented. However
154	if you want to go for "manual mode" just write 1 to pwmN_enable.
155	
156	If you are only able to control the fan speed with very small PWM values,
157	try lowering the PWM base frequency (pwm1_freq). Depending on the fan,
158	it may give you a somewhat greater control range. The same frequency is
159	used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are
160	read-only.
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