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1 | Kernel driver it87 |
2 | ================== | |
3 | ||
4 | Supported chips: | |
5 | * IT8705F | |
6 | Prefix: 'it87' | |
91749996 | 7 | Addresses scanned: from Super I/O config space (8 I/O ports) |
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8 | Datasheet: Publicly available at the ITE website |
9 | http://www.ite.com.tw/ | |
10 | * IT8712F | |
11 | Prefix: 'it8712' | |
c5e3fbf2 | 12 | Addresses scanned: I2C 0x2d |
91749996 | 13 | from Super I/O config space (8 I/O ports) |
7f15b664 M |
14 | Datasheet: Publicly available at the ITE website |
15 | http://www.ite.com.tw/ | |
16 | * SiS950 [clone of IT8705F] | |
91749996 JD |
17 | Prefix: 'it87' |
18 | Addresses scanned: from Super I/O config space (8 I/O ports) | |
7f15b664 M |
19 | Datasheet: No longer be available |
20 | ||
21 | Author: Christophe Gauthron <chrisg@0-in.com> | |
22 | ||
23 | ||
24 | Module Parameters | |
25 | ----------------- | |
26 | ||
27 | * update_vbat: int | |
28 | ||
29 | 0 if vbat should report power on value, 1 if vbat should be updated after | |
30 | each read. Default is 0. On some boards the battery voltage is provided | |
31 | by either the battery or the onboard power supply. Only the first reading | |
32 | at power on will be the actual battery voltage (which the chip does | |
33 | automatically). On other boards the battery voltage is always fed to | |
34 | the chip so can be read at any time. Excessive reading may decrease | |
35 | battery life but no information is given in the datasheet. | |
36 | ||
37 | * fix_pwm_polarity int | |
38 | ||
39 | Force PWM polarity to active high (DANGEROUS). Some chips are | |
40 | misconfigured by BIOS - PWM values would be inverted. This option tries | |
41 | to fix this. Please contact your BIOS manufacturer and ask him for fix. | |
42 | ||
43 | Description | |
44 | ----------- | |
45 | ||
46 | This driver implements support for the IT8705F, IT8712F and SiS950 chips. | |
47 | ||
48 | This driver also supports IT8712F, which adds SMBus access, and a VID | |
49 | input, used to report the Vcore voltage of the Pentium processor. | |
50 | The IT8712F additionally features VID inputs. | |
51 | ||
52 | These chips are 'Super I/O chips', supporting floppy disks, infrared ports, | |
53 | joysticks and other miscellaneous stuff. For hardware monitoring, they | |
54 | include an 'environment controller' with 3 temperature sensors, 3 fan | |
55 | rotation speed sensors, 8 voltage sensors, and associated alarms. | |
56 | ||
57 | Temperatures are measured in degrees Celsius. An alarm is triggered once | |
58 | when the Overtemperature Shutdown limit is crossed. | |
59 | ||
60 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is | |
61 | triggered if the rotation speed has dropped below a programmable limit. Fan | |
62 | readings can be divided by a programmable divider (1, 2, 4 or 8) to give the | |
63 | readings more range or accuracy. Not all RPM values can accurately be | |
64 | represented, so some rounding is done. With a divider of 2, the lowest | |
65 | representable value is around 2600 RPM. | |
66 | ||
67 | Voltage sensors (also known as IN sensors) report their values in volts. An | |
68 | alarm is triggered if the voltage has crossed a programmable minimum or | |
69 | maximum limit. Note that minimum in this case always means 'closest to | |
70 | zero'; this is important for negative voltage measurements. All voltage | |
71 | inputs can measure voltages between 0 and 4.08 volts, with a resolution of | |
72 | 0.016 volt. The battery voltage in8 does not have limit registers. | |
73 | ||
74 | The VID lines (IT8712F only) encode the core voltage value: the voltage | |
75 | level your processor should work with. This is hardcoded by the mainboard | |
76 | and/or processor itself. It is a value in volts. | |
77 | ||
78 | If an alarm triggers, it will remain triggered until the hardware register | |
79 | is read at least once. This means that the cause for the alarm may already | |
80 | have disappeared! Note that in the current implementation, all hardware | |
81 | registers are read whenever any data is read (unless it is less than 1.5 | |
82 | seconds since the last update). This means that you can easily miss | |
83 | once-only alarms. | |
84 | ||
85 | The IT87xx only updates its values each 1.5 seconds; reading it more often | |
86 | will do no harm, but will return 'old' values. | |
87 | ||
88 | To change sensor N to a thermistor, 'echo 2 > tempN_type' where N is 1, 2, | |
89 | or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'. | |
90 | Give 0 for unused sensor. Any other value is invalid. To configure this at | |
91 | startup, consult lm_sensors's /etc/sensors.conf. (2 = thermistor; | |
92 | 3 = thermal diode) | |
93 | ||
94 | The fan speed control features are limited to manual PWM mode. Automatic | |
95 | "Smart Guardian" mode control handling is not implemented. However | |
96 | if you want to go for "manual mode" just write 1 to pwmN_enable. |