Kernel driver max31790

Supported chips:

Author: Il Han <corone.il.han@gmail.com>

Description

This driver implements support for the Maxim MAX31790 chip.

The MAX31790 controls the speeds of up to six fans using six independentPWM outputs. The desired fan speeds (or PWM duty cycles) are writtenthrough the I2C interface. The outputs drive “4-wire” fans directly,or can be used to modulate the fan’s power terminals using an externalpass transistor.

Tachometer inputs monitor fan tachometer logic outputs for precise (+/-1%)monitoring and control of fan RPM as well as detection of fan failure.Six pins are dedicated tachometer inputs. Any of the six PWM outputs canalso be configured to serve as tachometer inputs.

Sysfs entries

fan[1-12]_input

RO

fan tachometer speed in RPM

fan[1-12]_fault

RO

fan experienced fault

fan[1-6]_target

RW

desired fan speed in RPM

fan[1-6]_enable

RW

enable or disable the tachometer input

pwm[1-6]_enable

RW

regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode

pwm[1-6]

RW

read: current pwm duty cycle,write: target pwm duty cycle (0-255)