1Kernel driver w83791d
2=====================
3
4Supported chips:
5
6  * Winbond W83791D
7
8    Prefix: 'w83791d'
9
10    Addresses scanned: I2C 0x2c - 0x2f
11
12    Datasheet: http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83791D_W83791Gb.pdf
13
14Author: Charles Spirakis <bezaur@gmail.com>
15
16This driver was derived from the w83781d.c and w83792d.c source files.
17
18Credits:
19
20  w83781d.c:
21
22    - Frodo Looijaard <frodol@dds.nl>,
23    - Philip Edelbrock <phil@netroedge.com>,
24    - Mark Studebaker <mdsxyz123@yahoo.com>
25
26  w83792d.c:
27
28    - Shane Huang (Winbond),
29    - Rudolf Marek <r.marek@assembler.cz>
30
31Additional contributors:
32
33    - Sven Anders <anders@anduras.de>
34    - Marc Hulsman <m.hulsman@tudelft.nl>
35
36Module Parameters
37-----------------
38
39* init boolean
40    (default 0)
41
42    Use 'init=1' to have the driver do extra software initializations.
43    The default behavior is to do the minimum initialization possible
44    and depend on the BIOS to properly setup the chip. If you know you
45    have a w83791d and you're having problems, try init=1 before trying
46    reset=1.
47
48* reset boolean
49    (default 0)
50
51    Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default
52    behavior is no chip reset to preserve BIOS settings.
53
54* force_subclients=bus,caddr,saddr,saddr
55    This is used to force the i2c addresses for subclients of
56    a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b`
57    to force the subclients of chip 0x2f on bus 0 to i2c addresses
58    0x4a and 0x4b.
59
60
61Description
62-----------
63
64This driver implements support for the Winbond W83791D chip. The W83791G
65chip appears to be the same as the W83791D but is lead free.
66
67Detection of the chip can sometimes be foiled because it can be in an
68internal state that allows no clean access (Bank with ID register is not
69currently selected). If you know the address of the chip, use a 'force'
70parameter; this will put it into a more well-behaved state first.
71
72The driver implements three temperature sensors, ten voltage sensors,
73five fan rotation speed sensors and manual PWM control of each fan.
74
75Temperatures are measured in degrees Celsius and measurement resolution is 1
76degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
77the temperature gets higher than the Overtemperature Shutdown value; it stays
78on until the temperature falls below the Hysteresis value.
79
80Voltage sensors (also known as IN sensors) report their values in millivolts.
81An alarm is triggered if the voltage has crossed a programmable minimum
82or maximum limit.
83
84Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
85triggered if the rotation speed has dropped below a programmable limit. Fan
86readings can be divided by a programmable divider (1, 2, 4, 8, 16,
8732, 64 or 128 for all fans) to give the readings more range or accuracy.
88
89Each fan controlled is controlled by PWM. The PWM duty cycle can be read and
90set for each fan separately. Valid values range from 0 (stop) to 255 (full).
91PWM 1-3 support Thermal Cruise mode, in which the PWMs are automatically
92regulated to keep respectively temp 1-3 at a certain target temperature.
93See below for the description of the sysfs-interface.
94
95The w83791d has a global bit used to enable beeping from the speaker when an
96alarm is triggered as well as a bitmask to enable or disable the beep for
97specific alarms. You need both the global beep enable bit and the
98corresponding beep bit to be on for a triggered alarm to sound a beep.
99
100The sysfs interface to the global enable is via the sysfs beep_enable file.
101This file is used for both legacy and new code.
102
103The sysfs interface to the beep bitmask has migrated from the original legacy
104method of a single sysfs beep_mask file to a newer method using multiple
105`*_beep` files as described in `Documentation/hwmon/sysfs-interface.rst`.
106
107A similar change has occurred for the bitmap corresponding to the alarms. The
108original legacy method used a single sysfs alarms file containing a bitmap
109of triggered alarms. The newer method uses multiple sysfs `*_alarm` files
110(again following the pattern described in sysfs-interface).
111
112Since both methods read and write the underlying hardware, they can be used
113interchangeably and changes in one will automatically be reflected by
114the other. If you use the legacy bitmask method, your user-space code is
115responsible for handling the fact that the alarms and beep_mask bitmaps
116are not the same (see the table below).
117
118NOTE: All new code should be written to use the newer sysfs-interface
119specification as that avoids bitmap problems and is the preferred interface
120going forward.
121
122The driver reads the hardware chip values at most once every three seconds.
123User mode code requesting values more often will receive cached values.
124
125/sys files
126----------
127The sysfs-interface is documented in the 'sysfs-interface' file. Only
128chip-specific options are documented here.
129
130======================= =======================================================
131pwm[1-3]_enable		this file controls mode of fan/temperature control for
132			fan 1-3. Fan/PWM 4-5 only support manual mode.
133
134			    * 1 Manual mode
135			    * 2 Thermal Cruise mode
136			    * 3 Fan Speed Cruise mode (no further support)
137
138temp[1-3]_target	defines the target temperature for Thermal Cruise mode.
139			Unit: millidegree Celsius
140			RW
141
142temp[1-3]_tolerance	temperature tolerance for Thermal Cruise mode.
143			Specifies an interval around the target temperature
144			in which the fan speed is not changed.
145			Unit: millidegree Celsius
146			RW
147======================= =======================================================
148
149Alarms bitmap vs. beep_mask bitmask
150-----------------------------------
151
152For legacy code using the alarms and beep_mask files:
153
154=============  ========  ========= ==========================
155Signal         Alarms    beep_mask Obs
156=============  ========  ========= ==========================
157in0 (VCORE)    0x000001  0x000001
158in1 (VINR0)    0x000002  0x002000  <== mismatch
159in2 (+3.3VIN)  0x000004  0x000004
160in3 (5VDD)     0x000008  0x000008
161in4 (+12VIN)   0x000100  0x000100
162in5 (-12VIN)   0x000200  0x000200
163in6 (-5VIN)    0x000400  0x000400
164in7 (VSB)      0x080000  0x010000  <== mismatch
165in8 (VBAT)     0x100000  0x020000  <== mismatch
166in9 (VINR1)    0x004000  0x004000
167temp1          0x000010  0x000010
168temp2          0x000020  0x000020
169temp3          0x002000  0x000002  <== mismatch
170fan1           0x000040  0x000040
171fan2           0x000080  0x000080
172fan3           0x000800  0x000800
173fan4           0x200000  0x200000
174fan5           0x400000  0x400000
175tart1          0x010000  0x040000  <== mismatch
176tart2          0x020000  0x080000  <== mismatch
177tart3          0x040000  0x100000  <== mismatch
178case_open      0x001000  0x001000
179global_enable  -         0x800000  (modified via beep_enable)
180=============  ========  ========= ==========================
181