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