#!/bin/sh
#
# /usr/local/sbin/freq
#   simple command line interface to cpufreq
#
# Michael Ossmann
#   Original work
# Jean Delvare
#   ACPI support
#   New inferface (/proc/cpufreq) support
#
# TODO: SMP support

freq_usage ()
{
  echo "Usage: $0 [min|max|acpif|perf|power|acpip]"
  echo "  min: set frequency to minimum"
  echo "  max: set frequency to maximum"
  echo "  acpif: use ACPI to choose frequency"
  echo "  perf: set policy to performance"
  echo "  power: set policy to powersave"
  echo "  acpip: use ACPI to choose policy"
  exit 1
}

if [ -r /proc/cpufreq ]
then
  [ -n "$1" ] && case "$1" in
    "min" )
      # set frequency to minimum
      echo -n '0%0%0%powersave' > /proc/cpufreq
      grep 'CPU  0' /proc/cpufreq
      exit 0
      ;;
    "max" )
      # set frequency to maximum
      echo -n '0%100%100%performance' > /proc/cpufreq
      grep 'CPU  0' /proc/cpufreq
      exit 0
      ;;
    "acpi" )
      echo "Use of \"acpi\" is deprecated, plese use \"acpif\" instead."
      exit 1
      ;;
    "acpif" )
      # use ACPI to choose frequency
      if [ ! -r /proc/acpi/ac_adapter/*/state ]
      then
        echo "Missing ACPI support"
        exit 1
      fi
      if grep 'off-line' /proc/acpi/ac_adapter/*/state > /dev/null
      then
        echo -n '0%0%0%powersave' > /proc/cpufreq
      else
        echo -n '0%100%100%performance' > /proc/cpufreq
      fi
      grep 'CPU  0' /proc/cpufreq
      exit 0
      ;;
    "perf" )
      # set policy to performance
      echo -n '0%0%100%performance' > /proc/cpufreq
      grep 'CPU  0' /proc/cpufreq
      exit 0
      ;;
    "power" )
      # set policy to powersave
      echo -n '0%0%100%powersave' > /proc/cpufreq
      grep 'CPU  0' /proc/cpufreq
      exit 0
      ;;
    "acpip" )
      # use ACPI to choose policy
      if [ ! -r /proc/acpi/ac_adapter/*/state ]
      then
        echo "Missing ACPI support"
        exit 1
      fi
      if grep 'off-line' /proc/acpi/ac_adapter/*/state > /dev/null
      then
        echo -n '0%0%100%powersave' > /proc/cpufreq
      else
        echo -n '0%0%100%performance' > /proc/cpufreq
      fi
      grep 'CPU  0' /proc/cpufreq
      exit 0
      ;;
    * )
      freq_usage
      ;;
  esac

  # display current frequency
  grep 'CPU  0' /proc/cpufreq
  exit 0
fi

if [ -r /proc/sys/cpu/0/speed ]
then
  [ -n "$1" ] && case "$1" in
    "min" | "power" )
      # set frequency to minimum
      cat /proc/sys/cpu/0/speed-min > /proc/sys/cpu/0/speed
      echo "CPU 0 frequency set to $(cat /proc/sys/cpu/0/speed) MHz"
      exit 0
      ;;
    "max" | "perf" )
      # set frequency to maximum
      cat /proc/sys/cpu/0/speed-max > /proc/sys/cpu/0/speed
      echo "CPU 0 frequency set to $(cat /proc/sys/cpu/0/speed) MHz"
      exit 0
      ;;
    "acpi" )
      echo "Use of \"acpi\" is deprecated, plese use \"acpif\" instead."
      exit 1
      ;;
    "acpif" | "acpip" )
      # use ACPI to choose frequency
      if [ ! -r /proc/acpi/ac_adapter/*/state ]
      then
        echo "Missing ACPI support"
        exit 1
      fi
      if grep 'off-line' /proc/acpi/ac_adapter/*/state > /dev/null
      then
        cat /proc/sys/cpu/0/speed-min > /proc/sys/cpu/0/speed
      else
        cat /proc/sys/cpu/0/speed-max > /proc/sys/cpu/0/speed
      fi
      echo "CPU 0 frequency set to $(cat /proc/sys/cpu/0/speed) MHz"
      exit 0
      ;;
    * )
      freq_usage
      ;;
  esac

  # display current frequency
  echo "CPU 0 frequency $(cat /proc/sys/cpu/0/speed) MHz"
  exit 0
fi

echo "Missing cpufreq support"
exit 1