XG-7100_fan.sh

#!/bin/sh
#
# Script to control the fan on the XG-7100.
# The EMC2104 is accessed via the smbus on the ICH.
#
# SteveW 24/01/2019
#

# Variables
smb_dev="/dev/null"
smb_led_dev="/dev/null"
fan_speed=0
start_speed=96
minimum_speed=60
maximum_speed=255
interval=2
hysteresis=1
ramp_rate=2
target_temp=38
verbose=false
coretemp=0

target_low=`expr $target_temp - $hysteresis`
target_high=`expr $target_temp + $hysteresis`

# Load required modules if they are not loaded
for mod in ichsmb ismt smb coretemp; do
    kldstat | grep " $mod.ko" > /dev/null
        if [ $? -eq 1 ]
            then
            kldload $mod
            $verbose && echo "$mod loaded"
            else
            $verbose && echo "$mod already loaded"
        fi
done

# Test we can "see" the fan controller on the smbus

    if [ "$(smbmsg -f /dev/smb0 -s 0x5e -c 0xfd -i 1)" = 0x1d ]
        then
        smb_dev="/dev/smb0"
        smb_led_dev="/dev/smb1"
        $verbose && echo "Found EMC2104 on $smb_dev"
        else
            if [ "$(smbmsg -f /dev/smb1 -s 0x5e -c 0xfd -i 1)" = 0x1d ]
            then
            smb_dev="/dev/smb1"
            smb_led_dev="/dev/smb0"
            $verbose && echo "Found EMC2104 on $smb_dev"
            else
            echo "EMC2104 not found"
            exit 1
            fi
    fi

# Set both fan controller to manual drive mode
smbmsg -f $smb_dev -s 0x5e -c 0x50 -o 1 0x10
smbmsg -f $smb_dev -s 0x5e -c 0x90 -o 1 0x10
$verbose && echo "Fan controllers set to manual"

# Read initial Coretemp Value
core_temp=`sysctl -n dev.cpu.0.temperature | cut -c1-2`
$verbose && echo "CPU temperature is $core_temp"

# Set Fan start speeds
smbmsg -f $smb_dev -s 0x5e -c 0x40 -o 1 $start_speed
smbmsg -f $smb_dev -s 0x5e -c 0x80 -o 1 $start_speed
fan_speed=$start_speed

# Fan control loop
logger Fan control started

while true; do
    core_temp=`sysctl -n dev.cpu.0.temperature | cut -c1-2`
    echo "Coretemp0 is $core_temp, Fanspeed is $fan_speed"

    if [ $core_temp -gt $target_high ]
        then
        fan_speed=`expr $fan_speed + $ramp_rate`
        $verbose && echo "Fanspeed increase"
        else
             if [ $core_temp -lt $target_low ] && [ $fan_speed -gt $minimum_speed ]
             then
             fan_speed=`expr $fan_speed - $ramp_rate`
             $verbose && echo "Fanspeed decrease"
             else
             $verbose && echo "Fanspeed is good"
             fi
    fi
    $verbose && echo "New fanspeed is $fan_speed"
    smbmsg -f $smb_dev -s 0x5e -c 0x40 -o 1 $fan_speed
    smbmsg -f $smb_dev -s 0x5e -c 0x80 -o 1 $fan_speed

    smbmsg -f $smb_led_dev -s 0xb6 -c 0x3 -o 1 0x0   # turn off the LED
    sleep $interval
    smbmsg -f $smb_led_dev -s 0xb6 -c 0x3 -o 1 0x3   # turn on the orange (red & green) LED

done