Root/Documentation/hwmon/w83627ehf

1Kernel driver w83627ehf
2=======================
3
4Supported 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 W83667HG
18    Prefix: 'w83667hg'
19    Addresses scanned: ISA address retrieved from Super I/O registers
20    Datasheet: not available
21  * Winbond W83667HG-B
22    Prefix: 'w83667hg'
23    Addresses scanned: ISA address retrieved from Super I/O registers
24    Datasheet: Available from Nuvoton upon request
25  * Nuvoton NCT6775F/W83667HG-I
26    Prefix: 'nct6775'
27    Addresses scanned: ISA address retrieved from Super I/O registers
28    Datasheet: Available from Nuvoton upon request
29  * Nuvoton NCT6776F
30    Prefix: 'nct6776'
31    Addresses scanned: ISA address retrieved from Super I/O registers
32    Datasheet: Available from Nuvoton upon request
33
34Authors:
35        Jean Delvare <khali@linux-fr.org>
36        Yuan Mu (Winbond)
37        Rudolf Marek <r.marek@assembler.cz>
38        David Hubbard <david.c.hubbard@gmail.com>
39        Gong Jun <JGong@nuvoton.com>
40
41Description
42-----------
43
44This driver implements support for the Winbond W83627EHF, W83627EHG,
45W83627DHG, W83627DHG-P, W83667HG, W83667HG-B, W83667HG-I (NCT6775F),
46and NCT6776F super I/O chips. We will refer to them collectively as
47Winbond chips.
48
49The chips implement three temperature sensors (up to four for 667HG-B, and nine
50for NCT6775F and NCT6776F), five fan rotation speed sensors, ten analog voltage
51sensors (only nine for the 627DHG), one VID (6 pins for the 627EHF/EHG, 8 pins
52for the 627DHG and 667HG), alarms with beep warnings (control unimplemented),
53and some automatic fan regulation strategies (plus manual fan control mode).
54
55The temperature sensor sources on W82677HG-B, NCT6775F, and NCT6776F are
56configurable. temp4 and higher attributes are only reported if its temperature
57source differs from the temperature sources of the already reported temperature
58sensors. The configured source for each of the temperature sensors is provided
59in tempX_label.
60
61Temperatures are measured in degrees Celsius and measurement resolution is 1
62degC for temp1 and and 0.5 degC for temp2 and temp3. For temp4 and higher,
63resolution is 1 degC for W83667HG-B and 0.0 degC for NCT6775F and NCT6776F.
64An alarm is triggered when the temperature gets higher than high limit;
65it stays on until the temperature falls below the hysteresis value.
66Alarms are only supported for temp1, temp2, and temp3.
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, 16, 32, 64 or
71128) to give the readings more range or accuracy. The driver sets the most
72suitable fan divisor itself. Some fans might not be present because they
73share pins with other functions.
74
75Voltage sensors (also known as IN sensors) report their values in millivolts.
76An alarm is triggered if the voltage has crossed a programmable minimum
77or maximum limit.
78
79The driver supports automatic fan control mode known as Thermal Cruise.
80In this mode, the chip attempts to keep the measured temperature in a
81predefined temperature range. If the temperature goes out of range, fan
82is driven slower/faster to reach the predefined range again.
83
84The mode works for fan1-fan4. Mapping of temperatures to pwm outputs is as
85follows:
86
87temp1 -> pwm1
88temp2 -> pwm2
89temp3 -> pwm3
90prog -> pwm4 (not on 667HG and 667HG-B; the programmable setting is not
91           supported by the driver)
92
93/sys files
94----------
95
96name - this is a standard hwmon device entry. For the W83627EHF and W83627EHG,
97       it is set to "w83627ehf", for the W83627DHG it is set to "w83627dhg",
98       for the W83667HG and W83667HG-B it is set to "w83667hg", for NCT6775F it
99       is set to "nct6775", and for NCT6776F it is set to "nct6776".
100
101pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range:
102       0 (stop) to 255 (full)
103
104pwm[1-4]_enable - this file controls mode of fan/temperature control:
105    * 1 Manual mode, write to pwm file any value 0-255 (full speed)
106    * 2 "Thermal Cruise" mode
107    * 3 "Fan Speed Cruise" mode
108    * 4 "Smart Fan III" mode
109    * 5 "Smart Fan IV" mode
110
111    SmartFan III mode is not supported on NCT6776F.
112
113    SmartFan IV mode is configurable only if it was configured at system
114    startup, and is only supported for W83677HG-B, NCT6775F, and NCT6776F.
115    SmartFan IV operational parameters can not be configured at this time,
116    and the various pwm attributes are not used in SmartFan IV mode.
117    The attributes can be written to, which is useful if you plan to
118    configure the system for a different pwm mode. However, the information
119    returned when reading pwm attributes is unrelated to SmartFan IV
120    operation.
121
122pwm[1-4]_mode - controls if output is PWM or DC level
123        * 0 DC output (0 - 12v)
124        * 1 PWM output
125
126Thermal Cruise mode
127-------------------
128
129If the temperature is in the range defined by:
130
131pwm[1-4]_target - set target temperature, unit millidegree Celsius
132             (range 0 - 127000)
133pwm[1-4]_tolerance - tolerance, unit millidegree Celsius (range 0 - 15000)
134
135there are no changes to fan speed. Once the temperature leaves the interval,
136fan speed increases (temp is higher) or decreases if lower than desired.
137There are defined steps and times, but not exported by the driver yet.
138
139pwm[1-4]_min_output - minimum fan speed (range 1 - 255), when the temperature
140                      is below defined range.
141pwm[1-4]_stop_time - how many milliseconds [ms] must elapse to switch
142                      corresponding fan off. (when the temperature was below
143                      defined range).
144
145Note: last two functions are influenced by other control bits, not yet exported
146      by the driver, so a change might not have any effect.
147
148Implementation Details
149----------------------
150
151Future driver development should bear in mind that the following registers have
152different functions on the 627EHF and the 627DHG. Some registers also have
153different power-on default values, but BIOS should already be loading
154appropriate defaults. Note that bank selection must be performed as is currently
155done in the driver for all register addresses.
156
1570x49: only on DHG, selects temperature source for AUX fan, CPU fan0
1580x4a: not completely documented for the EHF and the DHG documentation assigns
159       different behavior to bits 7 and 6, including extending the temperature
160       input selection to SmartFan I, not just SmartFan III. Testing on the EHF
161       will reveal whether they are compatible or not.
162
1630x58: Chip ID: 0xa1=EHF 0xc1=DHG
1640x5e: only on DHG, has bits to enable "current mode" temperature detection and
165       critical temperature protection
1660x45b: only on EHF, bit 3, vin4 alarm (EHF supports 10 inputs, only 9 on DHG)
1670x552: only on EHF, vin4
1680x558: only on EHF, vin4 high limit
1690x559: only on EHF, vin4 low limit
1700x6b: only on DHG, SYS fan critical temperature
1710x6c: only on DHG, CPU fan0 critical temperature
1720x6d: only on DHG, AUX fan critical temperature
1730x6e: only on DHG, CPU fan1 critical temperature
174
1750x50-0x55 and 0x650-0x657 are marked "Test Register" for the EHF, but "Reserved
176       Register" for the DHG
177
178The DHG also supports PECI, where the DHG queries Intel CPU temperatures, and
179the ICH8 southbridge gets that data via PECI from the DHG, so that the
180southbridge drives the fans. And the DHG supports SST, a one-wire serial bus.
181
182The DHG-P has an additional automatic fan speed control mode named Smart Fan
183(TM) III+. This mode is not yet supported by the driver.
184

Archive Download this file



interactive