#!/bin/sh
#
# Script to install/revert custom cpufreq voltages
# using Linux-PHC patch sysfs interface 
# https://www.dedigentoo.org/trac/linux-phc/wiki
#
set -e

TABLE=/sys/devices/system/cpu/cpu0/cpufreq/op_points_table

# default voltages
# this should be changed to the line obtained by
# cat /sys/devices/system/cpu/cpu0/cpufreq/op_points_table
# before changing any of the freq/voltage pairs
DEF="600000:988,800000:1068,1000000:1132,1200000:1212,1400000:1276,1600000:1340"

# custom voltages
MOD="600000:700,800000:732,1000000:796,1200000:876,1400000:956,1600000:1052"

if [ -f $TABLE ]; then

	case "$1" in
	start)
		echo Setting custom cpufreq voltage pairs
		echo $MOD > $TABLE
		cat $TABLE
		;;
	stop)
		echo Restoring default cpufreq voltage pairs
		echo $DEF > $TABLE
		cat $TABLE
		;;
	*)
		echo "Usage: $0 {start|stop}"
		exit 2
		;;
	esac

	exit 0

else

	echo "Linux-PHC sysfs cpufreq voltage table interface does not exist"
	exit 1

fi