About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / hwmon / w83791d

Based on kernel version 2.6.26. Page generated on 2008-07-16 21:12 EST.

1	Kernel driver w83791d
2	=====================
3	
4	Supported chips:
5	  * Winbond W83791D
6	    Prefix: 'w83791d'
7	    Addresses scanned: I2C 0x2c - 0x2f
8	    Datasheet: http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83791D_W83791Gb.pdf
9	
10	Author: Charles Spirakis <bezaur[AT]gmail[DOT]com>
11	
12	This driver was derived from the w83781d.c and w83792d.c source files.
13	
14	Credits:
15	  w83781d.c:
16	    Frodo Looijaard <frodol[AT]dds[DOT]nl>,
17	    Philip Edelbrock <phil[AT]netroedge[DOT]com>,
18	    and Mark Studebaker <mdsxyz123[AT]yahoo[DOT]com>
19	  w83792d.c:
20	    Chunhao Huang <DZShen[AT]Winbond.com[DOT]tw>,
21	    Rudolf Marek <r.marek[AT]assembler[DOT]cz>
22	
23	Additional contributors:
24	    Sven Anders <anders[AT]anduras[DOT]de>
25	
26	Module Parameters
27	-----------------
28	
29	* init boolean
30	  (default 0)
31	  Use 'init=1' to have the driver do extra software initializations.
32	  The default behavior is to do the minimum initialization possible
33	  and depend on the BIOS to properly setup the chip. If you know you
34	  have a w83791d and you're having problems, try init=1 before trying
35	  reset=1.
36	
37	* reset boolean
38	  (default 0)
39	  Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default
40	  behavior is no chip reset to preserve BIOS settings.
41	
42	* force_subclients=bus,caddr,saddr,saddr
43	  This is used to force the i2c addresses for subclients of
44	  a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b'
45	  to force the subclients of chip 0x2f on bus 0 to i2c addresses
46	  0x4a and 0x4b.
47	
48	
49	Description
50	-----------
51	
52	This driver implements support for the Winbond W83791D chip. The W83791G
53	chip appears to be the same as the W83791D but is lead free.
54	
55	Detection of the chip can sometimes be foiled because it can be in an
56	internal state that allows no clean access (Bank with ID register is not
57	currently selected). If you know the address of the chip, use a 'force'
58	parameter; this will put it into a more well-behaved state first.
59	
60	The driver implements three temperature sensors, five fan rotation speed
61	sensors, and ten voltage sensors.
62	
63	Temperatures are measured in degrees Celsius and measurement resolution is 1
64	degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
65	the temperature gets higher than the Overtemperature Shutdown value; it stays
66	on until the temperature falls below the Hysteresis value.
67	
68	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
69	triggered if the rotation speed has dropped below a programmable limit. Fan
70	readings can be divided by a programmable divider (1, 2, 4, 8 for fan 1/2/3
71	and 1, 2, 4, 8, 16, 32, 64 or 128 for fan 4/5) to give the readings more
72	range or accuracy.
73	
74	Voltage sensors (also known as IN sensors) report their values in millivolts.
75	An alarm is triggered if the voltage has crossed a programmable minimum
76	or maximum limit.
77	
78	The w83791d has a global bit used to enable beeping from the speaker when an
79	alarm is triggered as well as a bitmask to enable or disable the beep for
80	specific alarms. You need both the global beep enable bit and the
81	corresponding beep bit to be on for a triggered alarm to sound a beep.
82	
83	The sysfs interface to the gloabal enable is via the sysfs beep_enable file.
84	This file is used for both legacy and new code.
85	
86	The sysfs interface to the beep bitmask has migrated from the original legacy
87	method of a single sysfs beep_mask file to a newer method using multiple
88	*_beep files as described in .../Documentation/hwmon/sysfs-interface.
89	
90	A similar change has occured for the bitmap corresponding to the alarms. The
91	original legacy method used a single sysfs alarms file containing a bitmap
92	of triggered alarms. The newer method uses multiple sysfs *_alarm files
93	(again following the pattern described in sysfs-interface).
94	
95	Since both methods read and write the underlying hardware, they can be used
96	interchangeably and changes in one will automatically be reflected by
97	the other. If you use the legacy bitmask method, your user-space code is
98	responsible for handling the fact that the alarms and beep_mask bitmaps
99	are not the same (see the table below).
100	
101	NOTE: All new code should be written to use the newer sysfs-interface
102	specification as that avoids bitmap problems and is the preferred interface
103	going forward.
104	
105	The driver reads the hardware chip values at most once every three seconds.
106	User mode code requesting values more often will receive cached values.
107	
108	Alarms bitmap vs. beep_mask bitmask
109	------------------------------------
110	For legacy code using the alarms and beep_mask files:
111	
112	in0 (VCORE)  :  alarms: 0x000001 beep_mask: 0x000001
113	in1 (VINR0)  :  alarms: 0x000002 beep_mask: 0x002000 <== mismatch
114	in2 (+3.3VIN):  alarms: 0x000004 beep_mask: 0x000004
115	in3 (5VDD)   :  alarms: 0x000008 beep_mask: 0x000008
116	in4 (+12VIN) :  alarms: 0x000100 beep_mask: 0x000100
117	in5 (-12VIN) :  alarms: 0x000200 beep_mask: 0x000200
118	in6 (-5VIN)  :  alarms: 0x000400 beep_mask: 0x000400
119	in7 (VSB)    :  alarms: 0x080000 beep_mask: 0x010000 <== mismatch
120	in8 (VBAT)   :  alarms: 0x100000 beep_mask: 0x020000 <== mismatch
121	in9 (VINR1)  :  alarms: 0x004000 beep_mask: 0x004000
122	temp1        :  alarms: 0x000010 beep_mask: 0x000010
123	temp2        :  alarms: 0x000020 beep_mask: 0x000020
124	temp3        :  alarms: 0x002000 beep_mask: 0x000002 <== mismatch
125	fan1         :  alarms: 0x000040 beep_mask: 0x000040
126	fan2         :  alarms: 0x000080 beep_mask: 0x000080
127	fan3         :  alarms: 0x000800 beep_mask: 0x000800
128	fan4         :  alarms: 0x200000 beep_mask: 0x200000
129	fan5         :  alarms: 0x400000 beep_mask: 0x400000
130	tart1        :  alarms: 0x010000 beep_mask: 0x040000 <== mismatch
131	tart2        :  alarms: 0x020000 beep_mask: 0x080000 <== mismatch
132	tart3        :  alarms: 0x040000 beep_mask: 0x100000 <== mismatch
133	case_open    :  alarms: 0x001000 beep_mask: 0x001000
134	global_enable:  alarms: -------- beep_mask: 0x800000 (modified via beep_enable)
135	
136	W83791D TODO:
137	---------------
138	Provide a patch for smart-fan control (still need appropriate motherboard/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.