A script for setting CPU frequency that I mainly use for my odroid-u3

setcpu.sh

#!/bin/bash
# change cpu frequency

max_cap=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq`
min_cap=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq`

# lowest ~ 1.71GHz by default
max_freq=1710000
min_freq=$min_cap

# or you can specify by arguments
while getopts ":a::i:" opt; do
    case $opt in
    a)
        max_freq=$OPTARG
        ;;
    i)
        min_freq=$OPTARG
        ;;
    \?)
        echo "Invalid option -$OPTARG"
        echo "Usage: ./setcpu.sh [OPTIONS]"
        echo "Options:"
        echo -e "  -a:\tSpecify maximum CPU frequency"
        echo -e "  -i:\tSpecify minimum CPU frequency"
        exit 1
        ;;
    esac
done

if [ $max_freq -gt $max_cap ]; then
    echo "ERROR: Maximum CPU frequency $max_freq is higher than the highest value you can set: $max_cap"
    exit 2
fi

if [ $min_freq -lt $min_cap ]; then
    echo "ERROR: Minimum CPU frequency $min_freq is lower than the lowest value you can set: $min_cap"
    exit 2
fi

if [ $max_freq -gt 1710000 ]; then
    echo "WARNING: Maximum CPU frequency $max_freq is a bit too high"
fi

# set one core affects cpu 0, 1, 2, 3 simultaneously
su -c "echo $max_freq > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq" 
su -c "echo $min_freq > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq" 

echo "Maximum CPU frequency is set to `cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq`"
echo "Minimum CPU frequency is set to `cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq`"