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    Shane Huang (Winbond),
21    Rudolf Marek <r.marek@assembler.cz>
22
23Additional contributors:
24    Sven Anders <anders@anduras.de>
25    Marc Hulsman <m.hulsman@tudelft.nl>
26
27Module Parameters
28-----------------
29
30* init boolean
31  (default 0)
32  Use 'init=1' to have the driver do extra software initializations.
33  The default behavior is to do the minimum initialization possible
34  and depend on the BIOS to properly setup the chip. If you know you
35  have a w83791d and you're having problems, try init=1 before trying
36  reset=1.
37
38* reset boolean
39  (default 0)
40  Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default
41  behavior is no chip reset to preserve BIOS settings.
42
43* force_subclients=bus,caddr,saddr,saddr
44  This is used to force the i2c addresses for subclients of
45  a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b'
46  to force the subclients of chip 0x2f on bus 0 to i2c addresses
47  0x4a and 0x4b.
48
49
50Description
51-----------
52
53This driver implements support for the Winbond W83791D chip. The W83791G
54chip appears to be the same as the W83791D but is lead free.
55
56Detection of the chip can sometimes be foiled because it can be in an
57internal state that allows no clean access (Bank with ID register is not
58currently selected). If you know the address of the chip, use a 'force'
59parameter; this will put it into a more well-behaved state first.
60
61The driver implements three temperature sensors, ten voltage sensors,
62five fan rotation speed sensors and manual PWM control of each fan.
63
64Temperatures are measured in degrees Celsius and measurement resolution is 1
65degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
66the temperature gets higher than the Overtemperature Shutdown value; it stays
67on until the temperature falls below the Hysteresis value.
68
69Voltage sensors (also known as IN sensors) report their values in millivolts.
70An alarm is triggered if the voltage has crossed a programmable minimum
71or maximum limit.
72
73Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
74triggered if the rotation speed has dropped below a programmable limit. Fan
75readings can be divided by a programmable divider (1, 2, 4, 8, 16,
7632, 64 or 128 for all fans) to give the readings more range or accuracy.
77
78Each fan controlled is controlled by PWM. The PWM duty cycle can be read and
79set for each fan separately. Valid values range from 0 (stop) to 255 (full).
80PWM 1-3 support Thermal Cruise mode, in which the PWMs are automatically
81regulated to keep respectively temp 1-3 at a certain target temperature.
82See below for the description of the sysfs-interface.
83
84The w83791d has a global bit used to enable beeping from the speaker when an
85alarm is triggered as well as a bitmask to enable or disable the beep for
86specific alarms. You need both the global beep enable bit and the
87corresponding beep bit to be on for a triggered alarm to sound a beep.
88
89The sysfs interface to the global enable is via the sysfs beep_enable file.
90This file is used for both legacy and new code.
91
92The sysfs interface to the beep bitmask has migrated from the original legacy
93method of a single sysfs beep_mask file to a newer method using multiple
94*_beep files as described in .../Documentation/hwmon/sysfs-interface.
95
96A similar change has occurred for the bitmap corresponding to the alarms. The
97original legacy method used a single sysfs alarms file containing a bitmap
98of triggered alarms. The newer method uses multiple sysfs *_alarm files
99(again following the pattern described in sysfs-interface).
100
101Since both methods read and write the underlying hardware, they can be used
102interchangeably and changes in one will automatically be reflected by
103the other. If you use the legacy bitmask method, your user-space code is
104responsible for handling the fact that the alarms and beep_mask bitmaps
105are not the same (see the table below).
106
107NOTE: All new code should be written to use the newer sysfs-interface
108specification as that avoids bitmap problems and is the preferred interface
109going forward.
110
111The driver reads the hardware chip values at most once every three seconds.
112User mode code requesting values more often will receive cached values.
113
114/sys files
115----------
116The sysfs-interface is documented in the 'sysfs-interface' file. Only
117chip-specific options are documented here.
118
119pwm[1-3]_enable -	this file controls mode of fan/temperature control for
120			fan 1-3. Fan/PWM 4-5 only support manual mode.
121		            * 1 Manual mode
122		            * 2 Thermal Cruise mode
123		            * 3 Fan Speed Cruise mode (no further support)
124
125temp[1-3]_target -	defines the target temperature for Thermal Cruise mode.
126			Unit: millidegree Celsius
127			RW
128
129temp[1-3]_tolerance -	temperature tolerance for Thermal Cruise mode.
130			Specifies an interval around the target temperature
131			in which the fan speed is not changed.
132			Unit: millidegree Celsius
133			RW
134
135Alarms bitmap vs. beep_mask bitmask
136------------------------------------
137For legacy code using the alarms and beep_mask files:
138
139in0 (VCORE)  :  alarms: 0x000001 beep_mask: 0x000001
140in1 (VINR0)  :  alarms: 0x000002 beep_mask: 0x002000 <== mismatch
141in2 (+3.3VIN):  alarms: 0x000004 beep_mask: 0x000004
142in3 (5VDD)   :  alarms: 0x000008 beep_mask: 0x000008
143in4 (+12VIN) :  alarms: 0x000100 beep_mask: 0x000100
144in5 (-12VIN) :  alarms: 0x000200 beep_mask: 0x000200
145in6 (-5VIN)  :  alarms: 0x000400 beep_mask: 0x000400
146in7 (VSB)    :  alarms: 0x080000 beep_mask: 0x010000 <== mismatch
147in8 (VBAT)   :  alarms: 0x100000 beep_mask: 0x020000 <== mismatch
148in9 (VINR1)  :  alarms: 0x004000 beep_mask: 0x004000
149temp1        :  alarms: 0x000010 beep_mask: 0x000010
150temp2        :  alarms: 0x000020 beep_mask: 0x000020
151temp3        :  alarms: 0x002000 beep_mask: 0x000002 <== mismatch
152fan1         :  alarms: 0x000040 beep_mask: 0x000040
153fan2         :  alarms: 0x000080 beep_mask: 0x000080
154fan3         :  alarms: 0x000800 beep_mask: 0x000800
155fan4         :  alarms: 0x200000 beep_mask: 0x200000
156fan5         :  alarms: 0x400000 beep_mask: 0x400000
157tart1        :  alarms: 0x010000 beep_mask: 0x040000 <== mismatch
158tart2        :  alarms: 0x020000 beep_mask: 0x080000 <== mismatch
159tart3        :  alarms: 0x040000 beep_mask: 0x100000 <== mismatch
160case_open    :  alarms: 0x001000 beep_mask: 0x001000
161global_enable:  alarms: -------- beep_mask: 0x800000 (modified via beep_enable)
162