#!/bin/bash

#############################################
# CPU speed setting tool                    #
# By Marcelo Goes <vanquirius@gentoo.org>   #
# Under GPLv2                               #
#############################################

# You must have properly configured frequency scaling before using this script
# I am not responsible if this script screws up your computer

# Please configure the variables below before using

# Location of /sys nodes for VCore and CPU speed
SYS_VCORE="/sys/bus/i2c/devices/0-004e/cpu0_vid"
SYS_CPUSPEED="/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed"

# VCore * 1000
# CPU Speed in MHz * 1000
SLOW_VCORE="1500"
SLOW_CPUSPEED="1300000"
MEDIUM_VCORE="1600"
MEDIUM_CPUSPEED="1800000"
FAST_VCORE="1625"
FAST_CPUSPEED="2160000"

##############################################
# No configuration necessary below this point#
##############################################

VERSION="0.2"
TARGET="slow"

SYS_VCORE_VALUE=$(cat ${SYS_VCORE})
SYS_CPUSPEED_VALUE=$(cat ${SYS_CPUSPEED})
USER=$(/usr/bin/whoami)

show_cpu_version () {
	echo "CPU speed setting tool ${VERSION} by Marcelo Goes <vanquirius@gentoo.org>"
}

show_version_usage () {
	show_cpu_version
	echo
	echo "Usage: cpu [slow|medium|fast]"
}

show_cpu_help () {
	show_version_usage
	echo "Options:"
	echo "  --help, -h              Display this information"
	echo "  --version, -v           Show version"
	echo "  slow                    Slow cpu settings"
	echo "  medium                  Medium cpu settings"
	echo "  fast                    Maximum cpu settings"
	echo "  custom                  Custom cpu settings"
}

show_cpu_speed () {
	SHOW_VCORE=$(echo "scale=3; ${SYS_VCORE_VALUE}/1000" | bc)
	echo "VCore: ${SHOW_VCORE}"
	SHOW_CPUSPEED=$(echo "scale=0; ${SYS_CPUSPEED_VALUE}/1000" | bc)
	echo "MHz: ${SHOW_CPUSPEED}"
}

show_current() {
	show_cpu_version
	echo
	echo "Current settings"
	echo
	show_cpu_speed	
}

set_cpu_speed() {
	if [ ${USER} != root ] ; then
		echo "Error: you must be root to do that."
		exit 1
	fi
	show_current
	if [ ${TARGET} == slow ] ; then
		echo "${SLOW_CPUSPEED}" > ${SYS_CPUSPEED}
		echo "${SLOW_VCORE}" > ${SYS_VCORE}
	fi
	if [ ${TARGET} == medium ] ; then
		echo "${MEDIUM_VCORE}" > ${SYS_VCORE}
		echo "${MEDIUM_CPUSPEED}" > ${SYS_CPUSPEED}
	fi
	if [ ${TARGET} == fast ] ; then
		echo "${FAST_VCORE}" > ${SYS_VCORE}
		echo "${FAST_CPUSPEED}" > ${SYS_CPUSPEED}
	fi
	if [ ${TARGET} == custom ] ; then
		echo "${CUSTOM_VCORE}" > ${SYS_VCORE}
		echo "${CUSTOM_CPUSPEED}" > ${SYS_CPUSPEED}
	fi
	SYS_VCORE_VALUE=$(cat ${SYS_VCORE})
	SYS_CPUSPEED_VALUE=$(cat ${SYS_CPUSPEED})
	echo
	echo "New settings"
	echo
	show_cpu_speed
}

set_slow() {
	TARGET="slow"
	set_cpu_speed
}

set_medium() {
	TARGET="medium"
	set_cpu_speed
}

set_fast() {
	TARGET="fast"
	set_cpu_speed
}

set_custom() {
	TARGET="custom"
	CUSTOM_VCORE="${SLOW_VCORE}"
	CUSTOM_CPUSPEED="${SLOW_CPUSPEED}"
	echo "Enter VCore:"
	read CUSTOM_VCORE
	echo "Got ${CUSTOM_VCORE}."
	echo "Enter CPU speed:"
	read CUSTOM_CPUSPEED
	echo "Got ${CUSTOM_CPUSPEED}."
	echo
	echo "Are you sure you want to continue? [y/n]"
	echo "Wrong values might damage your computer beyond repair."
	read TMP_OPT
	if [ ${TMP_OPT} == "y" ]; then
		set_cpu_speed
	else
		echo "Bailing out..."
		exit 1
	fi
}

# process arguments
for option in "$@" ; do
	case ${option} in
		--help|-h)
		show_cpu_help
		exit 0;;
		--version|-v)
		show_cpu_version
		exit 0;;
		show)
		show_current
		exit 0;;
		slow)
		set_slow
		exit 0;;
		medium)
		set_medium
		exit 0;;
		fast)
		set_fast
		exit 0;;
		custom)
		set_custom
		exit 0;;
		*)
		show_cpu_version
		exit 0;;
	esac
done

show_current
exit 0