#!/bin/sh
### BEGIN INIT INFO
# Provides:          loadcpufreq
# Required-Start:    $remote_fs
# Required-Stop:
# Default-Start:     2 3 4 5
# Default-Stop:
# Short-Description: Load kernel modules needed to enable cpufreq scaling
# Description:       Make it possible to save power by reducing
#                    the CPU speed when there is little to do.
### END INIT INFO
# License: GNU General Public License.
#
# Based on scripts found in the powernowd package version
# 0.97-1ubuntu6 on Ubuntu.
#
# This script is an interim solution until the default Debian packages
# will load the proper kernel modules at boot time.  Track #396117,
# #342014 and #367307 to see status on this.
# <URL:http://0pointer.de/blog/projects/dmi-based-module-autoloading.html>
# claim the later kernels support autoloading of these modules, so I
# guess In the future this script can be dropped. [pere 2007-05-12]

PATH=/sbin:/bin:/usr/sbin:/usr/bin
NAME=loadcpufreq

# Get lsb functions
. /lib/lsb/init-functions
. /etc/default/rcS

# Set a default value
ENABLE="true"
[ -f /etc/default/loadcpufreq ] && . /etc/default/loadcpufreq

set -e

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

load_detected_cpufreq_modules() {
    #if /usr/sbin/laptop-detect; then LAPTOP=1; fi
    CPUINFO=/proc/cpuinfo
    IOPORTS=/proc/ioports

    if [ ! -f $CPUINFO ] ; then
	echo "$CPUINFO not detected..." >&2
	return
    fi

    MODEL_NAME=$(grep '^model name' "$CPUINFO" | head -1 | sed -e 's/^.*: //;')
    MODEL_ID=$(grep -E '^model[[:space:]]+:' "$CPUINFO" | head -1 | sed -e 's/^.*: //;')
    CPU=$(grep -E '^cpud[^:]+:' "$CPUINFO" | head -1 | sed -e 's/^.*: //;')
    VENDOR_ID=$(grep -E '^vendor_id[^:]+:' "$CPUINFO" | head -1 | sed -e 's/^.*: //;')
    CPU_FAMILY=$(sed -e '/^cpu family/ {s/.*: //;p;Q};d' $CPUINFO)

    MODULE=
    MODULE_FALLBACK=acpi-cpufreq

    # Two modules for PIII-M depending the chipset.
    # modprobe speedstep-ich$EXT || modprobe speestep-smi$EXT
    # would be another way
    if [ -f $IOPORTS ] && grep -q 'Intel .*ICH' $IOPORTS ; then
	PIII_MODULE=speedstep-ich
    else
	PIII_MODULE=speedstep-smi
    fi

    case "$VENDOR_ID" in
        GenuineIntel*)
            # If the CPU has the est flag, it supports enhanced
            # speedstep and should use the acpi-cpufreq driver
            if [ "$(grep est $CPUINFO)" ]; then
		MODULE=acpi-cpufreq
            elif [ $CPU_FAMILY = 15 ]; then
            # Right. Check if it's a P4 without est.
                # Could be speedstep-ich, or could be p4-clockmod. 
                MODULE=speedstep-ich;
                # Disabled for now - the latency tends to be bad
                # enough to make it fairly pointless.
                # echo "FREQDRIVER=p4-clockmod" >/etc/default/powernowd
                # to override this
#               if [ $LAPTOP = "1" ]; then
#                   MODULE_FALLBACK=p4-clockmod;
#               fi
            else
        # So it doesn't have Enhanced Speedstep, and it's not a
        # P4. It could be a Speedstep PIII, or it may be
        # unsupported. There's no terribly good programmatic way
        # of telling.
                case "$MODEL_NAME" in
                    Intel\(R\)\ Pentium\(R\)\ III\ Mobile\ CPU*)
                        MODULE=$PIII_MODULE
                        ;;
        
        # JD: says this works with cpufreq_userspace

                    Mobile\ Intel\(R\)\ Pentium\(R\)\ III\ CPU\ -\ M*)
                        MODULE=$PIII_MODULE
                        ;;
        
        # https://bugzilla.ubuntu.com/show_bug.cgi?id=4262
        # UNCONFIRMED
                    Pentium\ III\ \(Coppermine\)*)
                        MODULE=$PIII_MODULE
                        ;;
                esac
            fi
            ;;
        AuthenticAMD*)
# Hurrah. This is nice and easy.
            case $CPU_FAMILY in
                5)
                    # K6
                    MODULE=powernow-k6
                    ;;
                6)
                    # K7
                    MODULE=powernow-k7
                    ;;
                15|16|17)
                    # K8
                    MODULE=powernow-k8
                    ;;
            esac
            ;;
        CentaurHauls*)
        # VIA
            if [ $CPU_FAMILY = 6 ]; then
					case $MODEL_ID in
						10) # VIA C7 VIA Esther
							MODULE=e_powersaver
						;;
						*)
							MODULE=longhaul
						;;
					esac
            fi
            ;;    
        GenuineTMx86*)
        # Transmeta
            if [ "$(grep longrun $CPUINFO)" ]; then
                MODULE=longrun
            fi
            ;;
    esac
}

load_modules() {
        #stop the kernel printk'ing at all while we load.
        PRINTK=$(cat /proc/sys/kernel/printk)
        [ "$VERBOSE" = no ] && echo "1 1 1 1" > /proc/sys/kernel/printk

        #build a list of current modules so we don't load a module twice
        LIST=$(/sbin/lsmod|awk '!/Module/ {print $1}')

        #get list of available modules (governors and helpers)
        LOC="/lib/modules/$(uname -r)/kernel/drivers/cpufreq"
        if [ -d $LOC ]; then
          MODAVAIL=$( ( find $LOC -type f -name "*.o" -printf "basename %f .o\n"; \
	      find $LOC -type f -name "*.ko" -printf "basename %f .ko\n" ) | /bin/sh)
        else
          MODAVAIL=""
        fi

        #echo "Loading cpufreq modules:"
        for mod in $MODAVAIL; do
        #        echo "     $mod"
                echo $LIST| grep -q -w "$mod" || modprobe $mod >/dev/null || /bin/true
        done

        #cpufreq is built in on powerpc; just return
        if [ "$(uname -m)" = "ppc" ]; then
                echo "$PRINTK" > /proc/sys/kernel/printk
                return 0
        fi

        #new style detection system
        if [ ! "$FREQDRIVER" = "" ]; then 
		# user overridden value in /etc/default/loadcpufreq
                modprobe "$FREQDRIVER"
		MODULE="$FREQDRIVER"
        else
	        load_detected_cpufreq_modules
		if [ ! -z "$MODULE" ] || [ ! -z "$MODULE_FALLBACK" ] ; then
		    if [ ! -z "$MODULE" ] && modprobe "$MODULE" 2>/dev/null ; then
			:
		    elif modprobe "$MODULE_FALLBACK" 2>/dev/null ; then
			MODULE="$MODULE_FALLBACK"
		    else
			unset MODULE
		    fi
		fi
        fi

        echo "$PRINTK" > /proc/sys/kernel/printk
}

check_kernel() {
	CPUFREQ=/sys/devices/system/cpu/cpu0/cpufreq

	if [ -z "$MODULE" ] || ([ -f "$CPUFREQ/scaling_governor" ] && \
		[ -f "$CPUFREQ/scaling_available_governors" ])
	then
		return 0
	else
		return 1
	fi
}

case "$1" in
  start)
       	log_action_begin_msg "Loading cpufreq kernel modules"
        [ -f /proc/modules ] && load_modules
	if check_kernel ; then
	    [ -z "$MODULE" ] && MODULE="none"
	    log_action_end_msg 0 "$MODULE"
	else
	    log_action_end_msg 1
	fi
	;;
  stop)
	;;
  restart|force-reload)
        $0 stop
	sleep 1
	$0 start
	#echo "$NAME."
	;;
  *)
	N=/etc/init.d/$NAME
	log_success_msg "Usage: $N {start|stop|restart|force-reload}" >&2
	exit 1
	;;
esac

exit 0