#!/bin/sh
# 
# apmd_proxy - program dispatcher for APM daemon
# Craig Markwardt (craigm@lheamail.gsfc.nasa.gov) 21 May 1999
# David Brownell (db@post.harvard.edu) 9 June 1999
#
# This shell script is called by the APM daemon (apmd) when the state
# of any power management function has changed.  The exact events that
# trigger the calling of apmd_proxy depend on how apmd was configured
# at compile time.
#
# Within this script the system administrator should put any commands
# or actions which should be performed upon state transitions.
#
# apmd_proxy is called with specific arguments that describe the event
# that has occurred.  It is this script's responsibility to query the
# hardware or the APM service (via /proc/apm) for more information,
# and to take the appropriate action.
#
# For example, apmd will call "apmd_proxy suspend system" just before
# the system is scheduled to go into suspend mode.  The administrator
# may wish to perform site-specific actions like unloading drivers or
# disabling the network interface.  When the system is resumed later,
# apmd will call "apmd_proxy resume normal", at which time those actions
# should be reversed.
#
# If the kernel APM driver is version 1.10 or higher (use the "apm"
# command to find out), apmd_proxy can return an error code for the
# suspend and standby events, indicating whether the pending mode
# should be rejected.  For example, apmd_proxy may decide if, based on
# CPU or network activity or user instructions, a suspend initiated by
# the APM BIOS should be rejected.
#
#    !! NOTE !!   This is not the apmd_proxy used on most Debian systems!
#
#   RETURN VALUE:
#     0 - nominal return; suspend and standby events are accepted
#     1 - reject a suspend or standby (MUST HAVE APM DRIVER 1.10 OR HIGHER)
#
# Here are the calling sequences for apmd_proxy:
#
# apmd_proxy start              - APM daemon has started
# apmd_proxy stop               - APM daemon is shutting down
# apmd_proxy suspend system     - APM system has requested suspend mode
# apmd_proxy suspend critical   - APM system indicates critical suspend (*)
# apmd_proxy standby system     - APM system has requested standby mode 
# apmd_proxy suspend user       - User has requested suspend mode
# apmd_proxy standby user       - User has requested standby mode
# apmd_proxy resume suspend     - System has resumed from suspend mode
# apmd_proxy resume standby     - System has resumed from standby mode
# apmd_proxy resume critical    - System has resumed from critical suspend
# apmd_proxy change battery     - APM system reported low battery
# apmd_proxy change power       - APM system reported AC/battery change
# apmd_proxy change time        - APM system reported need for time update (*)
# apmd_proxy change capability  - APM system reported config. change (+)
#
# (*) - APM daemon may be modified to call these sequences
# (+) - Available if kernel APM driver supports it (driver ver. 1.10 or higher)
#
# SIMPLIFIED CONFIGURATION  
#
# The operation of this script can be controlled either by setting the
# following variables appropriately, or by editing the script itself.
#
# Set UTC to true if your clock is based on UTC time.  This settting
# is overridden by any settings in /etc/sysconfig/clock.
UTC=false
#
# Set SUSPEND_ON_AC to false if you wish to avoid suspend and standby
# events when your machine is connected to AC power.  By default
# suspends can occur on either battery or AC power.
SUSPEND_ON_AC=true
#
# PCMCIA cards can be more or less amenable to an APM suspend event.
# If you have a card that cannot be suspended properly (such as a SCSI
# card), then it should be "ejected" before entering suspend mode.
# The cards are not physically ejected; rather, the power is turned
# off to them via the "cardctl eject" command, and is reactivated upon 
# resume.
PCMCIA_EJECT_ON_SUSPEND=false
#
#
# DEBUGGING
#
# Uncomment commands under either METHOD 1 or METHOD 2 for debugging
# messages to the system log.  Not recommended for general use, since
# it may activate your disk more than needed.  The second method will
# log all commands and error messages encountered by apmd_proxy.
#
# METHOD 1 - Logs command line arguments of apmd_proxy only
# logger apmd_proxy $*    
# METHOD 2 - Logs entire run of apmd_proxy to /tmp/apmd_proxy.log
# echo '****************' >> /tmp/apmd_proxy.log
# echo "$0 $*"            >> /tmp/apmd_proxy.log
# date                    >> /tmp/apmd_proxy.log
# echo '----------------' >> /tmp/apmd_proxy.log
# exec                   2>> /tmp/apmd_proxy.log
# set -x
#
# A convenience bash routine is included to show how to query AC power
# status.
#
# *******************************************************************


power_conserve() {
	# Set IDE hard disk spindown time to a short time
	# Disabled by default.
#	/sbin/hdparm -q -S 18 /dev/hda			# 18 == 1.5 minutes
	true;
}

power_performance() {
	# Disable IDE hard disk spindown
	# Disabled by default.
#	/sbin/hdparm -q -S 0 /dev/hda
	true;
}

# NOTE:  APM BIOS drivers in kernel 2.2 and later have handled this
update_clock () {
	# update kernel to match hardware clock
	if [ -f /etc/sysconfig/clock ]; then
	    . /etc/sysconfig/clock
	    # old style
	    if [ "$CLOCKMODE" = GMT ]; then
		UTC=true
	    fi
	fi
	if [ $UTC = false ]; then
	    FLAG=""
	else
	    FLAG="-u"
	fi
	[ -x /sbin/clock ] && clock -s $FLAG || hwclock -s $FLAG
}


# Start of main procedure.  Included are examples of some mild power
# management profiling, disabled by default.  Timer-based system
# suspends and standbys can be rejected if we are on AC power.
#

case "$1" in

  # ----------------------- SUSPEND and STANDBY ----------------------
  # Handle customized behavior for APM standby and suspend events
  # here.  Depending on your system, you may wish to enable some of
  # the example actions that follow.

  "suspend"|"standby")

	# Activate this segment if you wish to disable normal suspend
	# events when you are on AC power.  This segment only works if
	# your APM BIOS sends "suspend system" events after an idle
	# period.  Also, you must be running a Linux kernel APM
	# driver version 1.10 or higher (run "apm" to find out).
	#
	if [ $SUSPEND_ON_AC = false -a $2 = system ]; then
		if on_ac_power >/dev/null; then
			exit 1  # Reject (NOTE kernel support must be enabled)
		fi
	fi

	if [ $1 = standby ]; then
		exit 0
	fi
	# Standby events typically do not go past this point, but can
	# if you comment out the above lines.

	# Activate this segment if you wish to disable PCMCIA services
	# upon suspend events.  The PCMCIA driver nominally will
	# suspend all cards before reaching this point, but certain
	# cards cannot be suspended properly (notably, SCSI cards).
	# These cards must be forcefully software-ejected.  If you
	# uncomment this code, then be sure to also uncomment the
	# corresponding segment under RESUME.  Calling "cardctl
	# suspend" is needed for systems whose PCMCIA modules are
	# available but not APM-aware.  Calling it more than once is
	# not harmful.
	#
	if [ -x /sbin/cardctl ]; then 
		if [ $PCMCIA_EJECT_ON_SUSPEND = true ]; then
			/sbin/cardctl eject
		else
			/sbin/cardctl suspend
		fi
	fi

	# Uncomment this segment if your graphics card does not resume
	# in graphics mode properly (ie, in X windows).  This action
	# changes the screen to virtual console number 1, which is
	# usually a text console.  Upon resume, you will need to
	# change back to your X console manually.
	#
	# if [ -x /usr/bin/chvt ]; then
	# 	/usr/bin/chvt 1; sleep 1
	# fi

	# other common actions:  unload troublesome drivers
	# EXAMPLE: OSS sound may not suspend/resume properly
	#    - Unload the drivers here and then reload upon resume
	#      Path may vary.  Be sure to enable "soundon" below.
	#	/usr/local/bin/soundoff
	;;

  # ------------------------------- RESUME ---------------------------
  # Resume ... from standby is a NOP, except the clock update.
  "resume")
	# Typically the Linux system clock needs to be reset.
	update_clock

	# Activate this segment if you "ejected" PCMCIA cards above.
	# The default operation is to "resume", which is required for
	# systems whose PCMCIA modules are not APM-aware.
	#
	if [ $2 = suspend -a -x /sbin/cardctl ]; then
		if [ $PCMCIA_EJECT_ON_SUSPEND = true ]; then
			/sbin/cardctl insert
		else
			/sbin/cardctl resume
		fi
	fi

	# Drives can forget their time-out setting after suspend,
	# so we may have to reprogram the drive.
        if on_ac_power >/dev/null; then
                power_performance
        else
                power_conserve
        fi

	# other common actions:  reload troublesome drivers
	# EXAMPLE: reload OSS sound drivers.  Path may vary.
	#	/usr/local/bin/soundon
	;;

  # ------------------------------- START ----------------------------
  # Called when apmd first starts.
  # If we are on battery power, then attempt to "conserve" power.
  "start")
  	if on_ac_power >/dev/null; then
		power_performance
	else
		power_conserve
	fi
	;;

  # ------------------------------- STOP -----------------------------
  # Called when apmd is terminated.
  # Default mode, when apmd is off, is to be in "performance" mode.
  "stop")
	power_performance
	;; 

  # ------------------------ CHANGE in STATUS ------------------------
  "change")
	case $2 in
	    "power")
		# switched to/from AC power, added/removed battery, etc
		if on_ac_power >/dev/null; then
			power_performance
		else
			power_conserve
		fi
		;;
	    "time")
		# normally not called
		update_clock
		;;
	    "battery")
		# battery is at "low" level (BIOS defines -- e.g. as 50%)
		# can't do much of anything useful
		;;
	    "capability")
		# e.g. added new hardware (not battery!)
		;;
	esac
	;;

esac

exit 0