thermald replacement for arm singleboard

thermald.sh

#!/bin/bash

# get temperature and on thresholds change system frequencies to lower or higher
# tested only on Orange Pi 3 LTS

TEMPPATH="/sys/devices/virtual/thermal/thermal_zone*"
TEMPFILENAME="temp"
TEMP_MAX=84000
TEMP_MIN=77000

AVAIL_FREQ=/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
CURR_FREQ=/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

get_temp() {
    cat $TEMPPATH/$TEMPFILENAME | sort -n -r | head -1
}

get_lower_freq() {
    CFREQ=$(cat $CURR_FREQ)
    RET=$(cat $AVAIL_FREQ | cut -f1 -d' ')
    for i in $(cat $AVAIL_FREQ); do
        if [[ $CFREQ -gt $i ]]; then
            RET=$i
        fi
    done
    echo $RET
}

get_higher_freq() {
    CFREQ=$(cat $CURR_FREQ)
    RET=$(cat $AVAIL_FREQ | awk '{ print $(NF) }')
    for i in $(cat $AVAIL_FREQ | awk '{ for (i=NF; i>=1; i--) printf("%s ",$i);}'); do
        if [[ $CFREQ -lt $i ]]; then
            RET=$i
        fi
    done
    echo $RET
}

new_freq() {
    RET=$(cat $CURR_FREQ)
    TEMP=$(get_temp)
    if [[ $TEMP -gt $TEMP_MAX ]]; then
        RET=$(get_lower_freq)
    elif [[ $TEMP -lt $TEMP_MIN ]]; then
        RET=$(get_higher_freq)
    fi
    echo $RET
}

main() {
    CFREQ=$(cat $CURR_FREQ)
    NFREQ=$(new_freq)
    if [[ $CFREQ -ne $NFREQ ]]; then
        echo "temperature: $(get_temp), setting frequency to $NFREQ"
        cpufreq-set -u $NFREQ
    fi
}

main