#!/bin/sh
### BEGIN INIT INFO
# Provides:       cpufrequtils
# Required-Start: $remote_fs loadcpufreq
# Required-Stop:
# Default-Start:  2 3 4 5
# Default-Stop:
# Short-Description: set CPUFreq kernel parameters
# Description: utilities to deal with CPUFreq Linux 
#       kernel support
### END INIT INFO
# 

DESC="CPUFreq Utilities"

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
CPUFREQ_SET=/usr/bin/cpufreq-set
CPUFREQ_INFO=/usr/bin/cpufreq-info
CPUFREQ_OPTIONS=""

# use lsb-base
. /lib/lsb/init-functions

# Which governor to use. Must be one of the governors listed in:
#   cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
#
# and which limits to set. Both MIN_SPEED and MAX_SPEED must be values
# listed in:
#   cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
# a value of 0 for any of the two variables will disabling the use of 
# that limit variable.
#
# WARNING: the correct kernel module must already be loaded or compiled in.
# 
# Set ENABLE to "true" to let the script run at boot time.
# 
# eg:   ENABLE="true"
#       GOVERNOR="ondemand"
#       MAX_SPEED=1000
#       MIN_SPEED=500

ENABLE="true"
GOVERNOR="schedutil"
MAX_SPEED="0"
MIN_SPEED="0"

check_governor_avail() {
        info="/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors"
        if [ -f $info ] && grep -q "\<$GOVERNOR\>" $info ; then
                return 0;
        fi
        return 1;
}

[ -x $CPUFREQ_SET ] || exit 0

if [ -f /etc/default/cpufrequtils ] ; then
        . /etc/default/cpufrequtils
fi

# if not enabled then exit gracefully
[ "$ENABLE" = "true" ] || exit 0

if [ -n "$MAX_SPEED" ] && [ $MAX_SPEED != "0" ] ; then
        CPUFREQ_OPTIONS="$CPUFREQ_OPTIONS --max $MAX_SPEED"
fi

if [ -n "$MIN_SPEED" ] && [ $MIN_SPEED != "0" ] ; then
        CPUFREQ_OPTIONS="$CPUFREQ_OPTIONS --min $MIN_SPEED"
fi

if [ -n "$GOVERNOR" ] ; then
        CPUFREQ_OPTIONS="$CPUFREQ_OPTIONS --governor $GOVERNOR"
fi

CPUS=$(cat /proc/stat|sed -ne 's/^cpu\([[:digit:]]\+\).*/\1/p')
RETVAL=0
case "$1" in
        start|force-reload|restart|reload)
                log_action_begin_msg "$DESC: Setting $GOVERNOR CPUFreq governor"
                if check_governor_avail ; then
                        for cpu in $CPUS ; do
                                log_action_cont_msg "CPU${cpu}"
                                $CPUFREQ_SET --cpu $cpu $CPUFREQ_OPTIONS 2>&1 > /dev/null || \
                                        RETVAL=$?
                        done
                        log_action_end_msg $RETVAL ""
                else
                        log_action_cont_msg "disabled, governor not available"
                        log_action_end_msg $RETVAL
                fi
                ;;
        stop)
                ;;
        *)
                echo "Usage: $0 {start|stop|restart|reload|force-reload}"
                exit 1
esac

exit 0
