#!/bin/sh
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2025 IPFire Team  <info@ipfire.org>                           #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

. /etc/sysconfig/rc
. ${rc_functions}

# Load the configuration if it exists
if [ -r "/etc/sysconfig/cpupower" ]; then
	. /etc/sysconfig/cpupower
fi

# This function returns which governor to use
find_governor() {
	local driver

	# If a governor has been configured, we just use that one
	if [ -n "${GOVERNOR}" ]; then
		echo "${GOVERNOR}"
		return 0
	fi

	# Determine the driver
	if [ -r "/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver" ]; then
		driver="$(</sys/devices/system/cpu/cpu0/cpufreq/scaling_driver)"
	fi

	# Decide which governor to use based on the driver
	case "${driver}" in
		# If the driver could not be detected, we won't use anything
		"")
			;;

		# Intel P-State only supports performace and powersave. The latter
		# is rather implemented like ondemand in other cases.
		intel_pstate)
			echo "powersave"
			;;

		# For everything else use schedutil
		*)
			echo "schedutil"
			;;
	esac

	return 0
}

set_governor() {
	# Find the governor to use
	local governor="$(find_governor)"

	# If we could not detect a governor we don't have anything to do
	if [ -z "${governor}" ]; then
		return 0
	fi

	# Set the governor
	cpupower frequency-set --governor "${governor}" >/dev/null
}

case "${1}" in
	start)
		boot_mesg "Enabling CPU Power Saving Features..."
		set_governor
		evaluate_retval
		;;
	*)
		echo "Usage: ${0} {start}"
		exit 1
		;;
esac