Description¶

Fintek F718xx/F8000 Super I/O chips include complete hardware monitoringcapabilities. They can monitor up to 9 voltages, 4 fans and 3 temperaturesensors.

These chips also have fan controlling features, using either DC or PWM, inthree different modes (one manual, two automatic).

The driver assumes that no more than one chip is present, which seemsreasonable.

Monitoring¶

The Voltage, Fan and Temperature Monitoring uses the standard sysfsinterface as documented in sysfs-interface, without any exceptions.

Fan Control¶

Both PWM (pulse-width modulation) and DC fan speed control methods aresupported. The right one to use depends on external circuitry on themotherboard, so the driver assumes that the BIOS set the methodproperly.

Note that the lowest numbered temperature zone trip point corresponds tothe border between the highest and one but highest temperature zones, andvica versa. So the temperature zone trip points 1-4 (or 1-2) go from high tempto low temp! This is how things are implemented in the IC, and the drivermimics this.

There are 2 modes to specify the speed of the fan, PWM duty cycle (or DCvoltage) mode, where 0-100% duty cycle (0-100% of 12V) is specified. And RPMmode where the actual RPM of the fan (as measured) is controlled and the speedgets specified as 0-100% of the fan#_full_speed file.

Since both modes work in a 0-100% (mapped to 0-255) scale, there isn’t awhole lot of a difference when modifying fan control settings. The onlyimportant difference is that in RPM mode the 0-100% controls the fan speedbetween 0-100% of fan#_full_speed. It is assumed that if the BIOS programsRPM mode, it will also set fan#_full_speed properly, if it does not thenfan control will not work properly, unless you set a sane fan#_full_speedvalue yourself.

Switching between these modes requires re-initializing a whole bunch ofregisters, so the mode which the BIOS has set is kept. The mode isprinted when loading the driver.

Three different fan control modes are supported; the mode number is writtento the pwm#_enable file. Note that not all modes are supported on allchips, and some modes may only be available in RPM / PWM mode.Writing an unsupported mode will result in an invalid parameter error.

• 1: Manual modeYou ask for a specific PWM duty cycle / DC voltage or a specific % offan#_full_speed by writing to the pwm# file. This mode is onlyavailable on the F71858FG / F8000 if the fan channel is in RPM mode.
• 2: Normal auto modeYou can define a number of temperature/fan speed trip points, which % thefan should run at at this temp and which temp a fan should follow using thestandard sysfs interface. The number and type of trip points is chipdepended, see which files are available in sysfs.Fan/PWM channel 3 of the F8000 is always in this mode!
• 3: Thermostat mode (Only available on the F8000 when in duty cycle mode)The fan speed is regulated to keep the temp the fan is mapped to betweentemp#_auto_point2_temp and temp#_auto_point3_temp.

All of the automatic modes require that pwm1 corresponds to fan1, pwm2 tofan2 and pwm3 to fan3.