Kernel driver max31785

Supported chips:

Author: Andrew Jeffery <andrew@aj.id.au>

Description

The Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fanmanagement with temperature and remote voltage sensing. Various fan controlfeatures are provided, including PWM frequency control, temperature hysteresis,dual tachometer measurements, and fan health monitoring.

For dual-rotor configurations the MAX31785A exposes the second rotor tachometerreadings in attributes fan[5-8]_input. By contrast the MAX31785 only exposesthe slowest rotor measurement, and does so in the fan[1-4]_input attributes.

Usage Notes

This driver does not probe for PMBus devices. You will have to instantiatedevices explicitly.

Sysfs attributes

fan[1-4]_alarmFan alarm.
fan[1-4]_faultFan fault.
fan[1-8]_inputFan RPM. On the MAX31785A, inputs 5-8 correspond to thesecond rotor of fans 1-4
fan[1-4]_targetFan input target
in[1-6]_critCritical maximum output voltage
in[1-6]_crit_alarmOutput voltage critical high alarm
in[1-6]_inputMeasured output voltage
in[1-6]_label“vout[18-23]”
in[1-6]_lcritCritical minimum output voltage
in[1-6]_lcrit_alarmOutput voltage critical low alarm
in[1-6]_maxMaximum output voltage
in[1-6]_max_alarmOutput voltage high alarm
in[1-6]_minMinimum output voltage
in[1-6]_min_alarmOutput voltage low alarm
pwm[1-4]Fan target duty cycle (0..255)
pwm[1-4]_enable0: Full-speed1: Manual PWM control2: Automatic PWM (tach-feedback RPM fan-control)3: Automatic closed-loop (temp-feedback fan-control)
temp[1-11]_critCritical high temperature
temp[1-11]_crit_alarmChip temperature critical high alarm
temp[1-11]_inputMeasured temperature
temp[1-11]_maxMaximum temperature
temp[1-11]_max_alarmChip temperature high alarm