#!/bin/bash
#
# acerfand - Rudimentary automatic fan control for noisy Acer Aspire One models
#
# Author Rachel Greenham
#
ACERFAND_VERSION="0.07"
# version 0.07 (2009-03-14)
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 3
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
#
# Changelog:
# 0.07 - change fan-raw-state setting for 3309. may fix people's issues
#        i didn't have same issues but did find it repeatedly switching fan off unnecessarily
#        because it was misdetecting the fan state, and which was logging and keeping my hard drive alive.
# 0.06.1 - experimental limited release with different fan-off controls for 3309.
# 0.06 - getBiosVersion before reading acerfand.conf, to allow user to force version
# 0.05 - Regognise bios 3309 and autoselect as default
# 0.04 - Recognise bios 3305
# 0.03 - Recognise bios 3109
# 0.02 - Added support for recognising bios version and selecting ec reg values accordingly
# 0.01 - Initial version, no bios checking, works on <=v0.3114


LOGGER=$(which logger)
if [ ! -x $LOGGER ] ; then
	LOGGER="/usr/bin/logger"
fi
if [ ! -x $LOGGER ] ; then
	echo "Warning, logger can't be found. Will log to stdout"
	unset LOGGER
fi

LOGLEVEL="info"

log() {
	if [ ! -z "$LOGGER" ] ; then
		$LOGGER -p daemon.$LOGLEVEL -t acerfand "$@"
	else
		echo "$@"
	fi
}

info() {
	LOGLEVEL="info"
	log "$@"
}

notice() {
	LOGLEVEL="notice"
#	log "$@"
}

err() {
	LOGLEVEL="err"
	log "$@"
}

info "acerfand $ACERFAND_VERSION starting"

if pgrep acerfand  | grep -v $$ > /dev/null; then
	info "acerfand already running"
	exit 0
fi

ME=$(readlink -f $0)

BIOS_VERSION_3109="v0.3109"
BIOS_VERSION_3114="v0.3114"
BIOS_VERSION_3304="v0.3304"
BIOS_VERSION_3305="v0.3305"
BIOS_VERSION_3309="v0.3309"

BIOS_VERSION_DEFAULT=$BIOS_VERSION_3309

getBiosVersion() {
	DMIDECODE=$(which dmidecode)
	if [ -z $DMIDECODE ] ; then
		info "Can't find dmidecode. Assuming bios $BIOS_VERSION_DEFAULT"
		BIOS_VERSION=$BIOS_VERSION_DEFAULT
	else
		BIOS_VERSION=$($DMIDECODE -s bios-version)
		info "Detected bios version $BIOS_VERSION"
	fi
}

ACEREC=$(which acer_ec.pl)
if [ -z $ACEREC ] ; then
	ACEREC=$(dirname $ME)/acer_ec.pl
fi

if [ ! -r $ACEREC ] ; then
	err "acer_ec.pl can't be found"
	exit 1
fi

INTERVAL=5
FANOFF=60
FANAUTO=70

getBiosVersion

if [ -r "/etc/acerfand.conf" ] ; then
	source "/etc/acerfand.conf"
fi

case "$BIOS_VERSION" in
	"${BIOS_VERSION_3309}")
		#change: handle 3309 seperate 0xAF -> 0x20
		R_FAN=55
		R_TEMP=58
		FAN_CMD_OFF=20
		FAN_CMD_AUTO=00
		RAW_FAN_STATE_OFF="0x20"
		;;
	"${BIOS_VERSION_3304}" | "${BIOS_VERSION_3305}" )
		R_FAN=55
		R_TEMP=58
		FAN_CMD_OFF=af
		FAN_CMD_AUTO=00
		RAW_FAN_STATE_OFF="0xaf"
		;;
	"${BIOS_VERSION_3114}" | "${BIOS_VERSION_3109}")
		R_FAN=55
		R_TEMP=58
		FAN_CMD_OFF=1f
		FAN_CMD_AUTO=00
		RAW_FAN_STATE_OFF="0x1f"
		;;
	*)
		err "Unsupported bios version ${BIOS_VERSION} found. Aborting."
		exit 1
	;;
esac

FAN_STATE_UNRECOGNIZED=0
FAN_STATE_AUTO=1
FAN_STATE_OFF=2
FAN_STATE_NAMES=("Unrecognized" "Auto" "Off")
FAN_STATE_CMDS=("$FAN_CMD_OFF" "$FAN_CMD_AUTO" "$FAN_CMD_OFF")

acer_ec() {
	perl $ACEREC $@
}

getTemp() {
	TEMP=$[$(acer_ec ?= $R_TEMP | cut -f 3 -d' ')]
	notice "temp: $TEMP"
}

getRawFanState() {
	RAW_FAN_STATE=$(acer_ec ?= $R_FAN | cut -f 3 -d' ')
}

getFanState() {
	FAN_STATE=$FAN_STATE_UNRECOGNIZED
	getRawFanState
	if [ "$RAW_FAN_STATE" == "$RAW_FAN_STATE_OFF" ]; then
		FAN_STATE=$FAN_STATE_OFF
	else
		let A="$RAW_FAN_STATE & 0x10" || true
		if [ "$A == 0" ] ; then
			# ASSUMPTION: All values with nybble 1==0 denote auto
			FAN_STATE=$FAN_STATE_AUTO
		fi
	fi
	notice "read fan state ${FAN_STATE_NAMES[$FAN_STATE]}"
}

setFan() {
	info "Set fan ${FAN_STATE_NAMES[$1]}"
	acer_ec := $R_FAN ${FAN_STATE_CMDS[$1]} > /dev/null
}

govern() {
trap "info exiting;setFan $FAN_STATE_AUTO; exit" INT TERM EXIT
info "Starting to govern acer fan speed. Interval: $INTERVAL, fan-off: $FANOFF, fan-auto: $FANAUTO"
while true; do
	getTemp
	getFanState
#	info "Raw fan state: $RAW_FAN_STATE ; fan state: $FAN_STATE ; auto: $FAN_STATE_AUTO ; off: $FAN_STATE_OFF ; temp: $TEMP ; autotemp: $FANAUTO"
	case "$FAN_STATE" in
		$FAN_STATE_AUTO)
			if [ "$TEMP" -le "$FANOFF" ] ; then
				setFan $FAN_STATE_OFF
			fi
			;;
		$FAN_STATE_OFF)
			if [ "$TEMP" -ge "$FANAUTO" ] ; then
				setFan $FAN_STATE_AUTO
			fi
			;;
		*)
			# weird state. Let's turn it off,
			# then decide next time around
			info "Unexpected fan state $FAN_STATE"
			setFan $FAN_STATE_OFF
			;;
	esac
	sleep $INTERVAL
done
}

set -e

govern &