t620_fan_control.sh

#!/bin/bash

temp_threshold_low=40
temp_threshold_mid=50
temp_threshold_high=60
temp_threshold_max=70
power_threshold_low=180
power_threshold_mid=300
power_threshold_high=500
power_threshold_max=800

# process args
while getopts "v" opt; do
    case $opt in
        v)
            opt_verbose=true
            ;;
    esac
done


log() {
    if [ $opt_verbose ]; then
        if [ "$1" == "-n" ]; then
            echo -n "$2"
        else
            echo "$1"
        fi
    fi
}

dec_to_hex() {
    if [ -n "$1" ] && [ "$1" -eq "$1" ] 2>/dev/null; then
        echo $(printf '0x%02x' $1)
    fi
}

manual_fan_control() {
    if [ -z "$1" ]; then
        echo "Pass 1 or 0 to enable or disable manual control"
    else
        if [ "$1" -eq "1" ]; then
            log "Enabling manual control..."
            ipmitool raw 0x30 0x30 0x01 0x00 > /dev/null
        else
            log "Disabling manual control..."
            ipmitool raw 0x30 0x30 0x01 0x01 > /dev/null
        fi
    fi
}

# Examples
# Set all fans to 20% speed:
# fan_speed 20
#
# Set CPU fans to 100% speed:
# fan_speed 100 cpu
#
# Set PCI fans to lowst speed:
# fan_speed 0 pci
fan_speed() {
    local hex_speed=$(dec_to_hex $1)
    if [ -z "$hex_speed" ]; then
        ipmitool sdr type Fan | grep RPM
        echo "Pass percentage number to set fan speed."
        return 1
    fi

    if [ -z "$2" ]; then
        log "Setting all fans speed to $1% ($hex_speed)..."
        ipmitool raw 0x30 0x30 0x02 0xff $hex_speed > /dev/null
    elif [ "$2" == "cpu" ]; then
        log "Setting CPU fans speed to $1% ($hex_speed)..."
        ipmitool raw 0x30 0x30 0x02 0x00 $hex_speed > /dev/null # fan #1
        ipmitool raw 0x30 0x30 0x02 0x01 $hex_speed > /dev/null # fan #2
        ipmitool raw 0x30 0x30 0x02 0x03 $hex_speed > /dev/null # fan #4
        ipmitool raw 0x30 0x30 0x02 0x04 $hex_speed > /dev/null # fan #5
    elif [ "$2" == "pci" ]; then
        log "Setting PCI fans speed to $1% ($hex_speed)..."
        ipmitool raw 0x30 0x30 0x02 0x02 $hex_speed > /dev/null # fan #3
        ipmitool raw 0x30 0x30 0x02 0x05 $hex_speed > /dev/null # fan #6
    fi
}

get_temps_cpu() {
    local cpu_temps=$(ipmitool sdr type temperature | grep "3\." | grep -Po '\d+(?= degrees C)')
    cpu1_temp=$(echo $cpu_temps | awk '{print $1;}')
    cpu2_temp=$(echo $cpu_temps | awk '{print $2;}')
    cpu_temp=$(( cpu1_temp > cpu2_temp ? cpu1_temp : cpu2_temp ))
}

get_power_draw() {
    power_draw=$(ipmitool sdr type current | grep "7\." | grep -Po '\d+(?= Watts)')
}

# 1st param is CPU temp, 2nd is power draw.
update_fan_speed() {
    if [ -n "$1" ]; then
        if ([ "$1" -lt "$temp_threshold_low" ]); then
            fan_speed 10 cpu
        elif ([ "$1" -ge "$temp_threshold_low" ] && [ "$1" -lt "$temp_threshold_mid" ]); then
            fan_speed 20 cpu
        elif ([ "$1" -ge "$temp_threshold_mid" ] && [ "$1" -lt "$temp_threshold_high" ]); then
            fan_speed 50 cpu
        elif ([ "$1" -ge "$temp_threshold_high" ] && [ "$1" -lt "$temp_threshold_max" ]); then
            fan_speed 80 cpu
        else
            fan_speed 100 cpu
        fi
    fi
    if [ -n "$2" ]; then
        if ([ "$2" -lt "$power_threshold_low" ]); then
            fan_speed 10 pci
        elif ([ "$2" -ge "$power_threshold_low" ] && [ "$2" -lt "$power_threshold_mid" ]); then
            fan_speed 20 pci
        elif ([ "$2" -ge "$power_threshold_mid" ] && [ "$2" -lt "$power_threshold_high" ]); then
            fan_speed 40 pci
        elif ([ "$2" -ge "$power_threshold_high" ] && [ "$2" -lt "$power_threshold_max" ]); then
            fan_speed 60 pci
        else
            fan_speed 100 pci
        fi
    else
        echo "Pass in CPU and power draw as parameters."
    fi
}

# main procedures
echo "Starting T620 fan control script..."

manual_fan_control 1
fan_speed 50

# control fan speeds based on temperatures
while true; do
    sleep 10
    
    get_temps_cpu    
    get_power_draw
    log "CPU1: $cpu1_temp °C; CPU2: $cpu2_temp °C; Power: $power_draw"
    
    update_fan_speed $cpu_temp $power_draw
    
done