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

1	Kernel driver w83627ehf
2	=======================
3	
4	Supported chips:
5	  * Winbond W83627EHF/EHG (ISA access ONLY)
6	    Prefix: 'w83627ehf'
7	    Addresses scanned: ISA address retrieved from Super I/O registers
8	    Datasheet: not available
9	  * Winbond W83627DHG
10	    Prefix: 'w83627dhg'
11	    Addresses scanned: ISA address retrieved from Super I/O registers
12	    Datasheet: not available
13	  * Winbond W83627DHG-P
14	    Prefix: 'w83627dhg'
15	    Addresses scanned: ISA address retrieved from Super I/O registers
16	    Datasheet: not available
17	  * Winbond W83627UHG
18	    Prefix: 'w83627uhg'
19	    Addresses scanned: ISA address retrieved from Super I/O registers
20	    Datasheet: available from www.nuvoton.com
21	  * Winbond W83667HG
22	    Prefix: 'w83667hg'
23	    Addresses scanned: ISA address retrieved from Super I/O registers
24	    Datasheet: not available
25	  * Winbond W83667HG-B
26	    Prefix: 'w83667hg'
27	    Addresses scanned: ISA address retrieved from Super I/O registers
28	    Datasheet: Available from Nuvoton upon request
29	  * Nuvoton NCT6775F/W83667HG-I
30	    Prefix: 'nct6775'
31	    Addresses scanned: ISA address retrieved from Super I/O registers
32	    Datasheet: Available from Nuvoton upon request
33	  * Nuvoton NCT6776F
34	    Prefix: 'nct6776'
35	    Addresses scanned: ISA address retrieved from Super I/O registers
36	    Datasheet: Available from Nuvoton upon request
37	
38	Authors:
39	        Jean Delvare <khali@linux-fr.org>
40	        Yuan Mu (Winbond)
41	        Rudolf Marek <r.marek@assembler.cz>
42	        David Hubbard <david.c.hubbard@gmail.com>
43	        Gong Jun <JGong@nuvoton.com>
44	
45	Description
46	-----------
47	
48	This driver implements support for the Winbond W83627EHF, W83627EHG,
49	W83627DHG, W83627DHG-P, W83627UHG, W83667HG, W83667HG-B, W83667HG-I
50	(NCT6775F), and NCT6776F super I/O chips. We will refer to them collectively
51	as Winbond chips.
52	
53	The chips implement 3 to 4 temperature sensors (9 for NCT6775F and NCT6776F),
54	2 to 5 fan rotation speed sensors, 8 to 10 analog voltage sensors, one VID
55	(except for 627UHG), alarms with beep warnings (control unimplemented),
56	and some automatic fan regulation strategies (plus manual fan control mode).
57	
58	The temperature sensor sources on W82677HG-B, NCT6775F, and NCT6776F are
59	configurable. temp4 and higher attributes are only reported if its temperature
60	source differs from the temperature sources of the already reported temperature
61	sensors. The configured source for each of the temperature sensors is provided
62	in tempX_label.
63	
64	Temperatures are measured in degrees Celsius and measurement resolution is 1
65	degC for temp1 and and 0.5 degC for temp2 and temp3. For temp4 and higher,
66	resolution is 1 degC for W83667HG-B and 0.0 degC for NCT6775F and NCT6776F.
67	An alarm is triggered when the temperature gets higher than high limit;
68	it stays on until the temperature falls below the hysteresis value.
69	Alarms are only supported for temp1, temp2, and temp3.
70	
71	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
72	triggered if the rotation speed has dropped below a programmable limit. Fan
73	readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or
74	128) to give the readings more range or accuracy. The driver sets the most
75	suitable fan divisor itself. Some fans might not be present because they
76	share pins with other functions.
77	
78	Voltage sensors (also known as IN sensors) report their values in millivolts.
79	An alarm is triggered if the voltage has crossed a programmable minimum
80	or maximum limit.
81	
82	The driver supports automatic fan control mode known as Thermal Cruise.
83	In this mode, the chip attempts to keep the measured temperature in a
84	predefined temperature range. If the temperature goes out of range, fan
85	is driven slower/faster to reach the predefined range again.
86	
87	The mode works for fan1-fan4. Mapping of temperatures to pwm outputs is as
88	follows:
89	
90	temp1 -> pwm1
91	temp2 -> pwm2
92	temp3 -> pwm3 (not on 627UHG)
93	prog  -> pwm4 (not on 667HG and 667HG-B; the programmable setting is not
94		       supported by the driver)
95	
96	/sys files
97	----------
98	
99	name - this is a standard hwmon device entry, it contains the name of
100	       the device (see the prefix in the list of supported devices at
101	       the top of this file)
102	
103	pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range:
104		   0 (stop) to 255 (full)
105	
106	pwm[1-4]_enable - this file controls mode of fan/temperature control:
107		* 1 Manual mode, write to pwm file any value 0-255 (full speed)
108		* 2 "Thermal Cruise" mode
109		* 3 "Fan Speed Cruise" mode
110		* 4 "Smart Fan III" mode
111		* 5 "Smart Fan IV" mode
112	
113		SmartFan III mode is not supported on NCT6776F.
114	
115		SmartFan IV mode is configurable only if it was configured at system
116		startup, and is only supported for W83677HG-B, NCT6775F, and NCT6776F.
117		SmartFan IV operational parameters can not be configured at this time,
118		and the various pwm attributes are not used in SmartFan IV mode.
119		The attributes can be written to, which is useful if you plan to
120		configure the system for a different pwm mode. However, the information
121		returned when reading pwm attributes is unrelated to SmartFan IV
122		operation.
123	
124	pwm[1-4]_mode - controls if output is PWM or DC level
125	        * 0 DC output (0 - 12v)
126	        * 1 PWM output
127	
128	Thermal Cruise mode
129	-------------------
130	
131	If the temperature is in the range defined by:
132	
133	pwm[1-4]_target    - set target temperature, unit millidegree Celsius
134			     (range 0 - 127000)
135	pwm[1-4]_tolerance - tolerance, unit millidegree Celsius (range 0 - 15000)
136	
137	there are no changes to fan speed. Once the temperature leaves the interval,
138	fan speed increases (temp is higher) or decreases if lower than desired.
139	There are defined steps and times, but not exported by the driver yet.
140	
141	pwm[1-4]_min_output - minimum fan speed (range 1 - 255), when the temperature
142	                      is below defined range.
143	pwm[1-4]_stop_time  - how many milliseconds [ms] must elapse to switch
144	                      corresponding fan off. (when the temperature was below
145	                      defined range).
146	pwm[1-4]_start_output-minimum fan speed (range 1 - 255) when spinning up
147	pwm[1-4]_step_output- rate of fan speed change (1 - 255)
148	pwm[1-4]_stop_output- minimum fan speed (range 1 - 255) when spinning down
149	pwm[1-4]_max_output - maximum fan speed (range 1 - 255), when the temperature
150	                      is above defined range.
151	
152	Note: last six functions are influenced by other control bits, not yet exported
153	      by the driver, so a change might not have any effect.
154	
155	Implementation Details
156	----------------------
157	
158	Future driver development should bear in mind that the following registers have
159	different functions on the 627EHF and the 627DHG. Some registers also have
160	different power-on default values, but BIOS should already be loading
161	appropriate defaults. Note that bank selection must be performed as is currently
162	done in the driver for all register addresses.
163	
164	0x49:  only on DHG, selects temperature source for AUX fan, CPU fan0
165	0x4a:  not completely documented for the EHF and the DHG documentation assigns
166	       different behavior to bits 7 and 6, including extending the temperature
167	       input selection to SmartFan I, not just SmartFan III. Testing on the EHF
168	       will reveal whether they are compatible or not.
169	
170	0x58:  Chip ID: 0xa1=EHF 0xc1=DHG
171	0x5e:  only on DHG, has bits to enable "current mode" temperature detection and
172	       critical temperature protection
173	0x45b: only on EHF, bit 3, vin4 alarm (EHF supports 10 inputs, only 9 on DHG)
174	0x552: only on EHF, vin4
175	0x558: only on EHF, vin4 high limit
176	0x559: only on EHF, vin4 low limit
177	0x6b:  only on DHG, SYS fan critical temperature
178	0x6c:  only on DHG, CPU fan0 critical temperature
179	0x6d:  only on DHG, AUX fan critical temperature
180	0x6e:  only on DHG, CPU fan1 critical temperature
181	
182	0x50-0x55 and 0x650-0x657 are marked "Test Register" for the EHF, but "Reserved
183	       Register" for the DHG
184	
185	The DHG also supports PECI, where the DHG queries Intel CPU temperatures, and
186	the ICH8 southbridge gets that data via PECI from the DHG, so that the
187	southbridge drives the fans. And the DHG supports SST, a one-wire serial bus.
188	
189	The DHG-P has an additional automatic fan speed control mode named Smart Fan
190	(TM) III+. This mode is not yet supported by the driver.
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