#!/bin/sh
#
# Starts the proper sound driver type and version
#   this script starts and shuts down (properly?) either the
#   commercial oss driver (installed for different kernels) or
#   the alsa driver. Easier said than done. Beware, this is not
#   an elegant solution :-)
#
# CCRMA, nando@ccrma.stanford.edu; February 2000
# Copyright (c) by Fernando Lopez-Lezcano
#
# This script is based on a preexisting initialization script
# for oss I run at ccrma and on the alsasound script distributed 
# with the alsa sound driver. The alsasound script is Copyright 
# (c) by Jaroslav Kysela <perex@suse.cz> 
#
#  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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# Usage:
#
# /etc/rc.d/init.d/sounddriver start OSS|ALSA
#    /etc/sysconfg/sounddriver is sourced and can supply the default
#    value for DRIVER (either ALSA or OSS). If the file is not found
#    and alsa is installed, alsa is started. Otherwise oss is started
#    if it is found. The driver to start can also be manually selected
#    with the second parameter to the script. For alsa the oss mixer
#    and pcm emulation modules are started as well. 
#
# NOTE: the oss startup is unnecesarily complicated by the need at 
#       ccrma of being able to boot into different kernels and have
#       the sound driver work on all. Oss out of the box cannot do that. 
#       The driver has to be installed in a different directory for each 
#       kernel, and is not very happy to have other sound drivers around. 
#       Here at ccrma I install oss in the default location (/usr/lib/oss). 
#       During the installation of oss /usr/lib/oss has to be a real directory
#       (not a link) and no sound modules have to be present in /etc/conf.modules
#       (or /etc/modules.conf) - so move that file away before starting the
#       install).  After the driver is happily installed you can move back the 
#       conf.modules file to its home in /etc (and oss will not complain, but 
#       see below for more caveats). The oss installation directory is renamed
#       to /usr/lib/oss-KERNEL_VERSION and a link is made from /usr/lib/oss
#       to /usr/lib/oss-KERNEL_VERSION. This script will keep the link pointed
#       to the proper version of the driver for the kernel that is running. 
#       Sigh. Alsa is also modular but it is installed in the modules directory
#       for the kernel so kernel version matching is handled automatically.
#       As it should be....
#
# NOTE: /etc/sndstat is a problem. It is a link in alsa and a device
#       in oss. It is erased when any of the two drivers stops and restored 
#       automatically by the oss startup program soundon and by hand
#       thorough this script when alsa restarts. If left over oss gets
#       thoroughly confused and the alsa modules get loaded as a side effect
#       of doing a cat /dev/sndstat in the soundon script (as far as I can tell
#       from a cursory debugging session)... so oss can't start at all. 
#
# ALSA Mixer: it is automatically reloaded by alsactl from the defaults
#             stored in /etc/asound.conf, use alsactl to create it. 
# OSS Mixer: it is automatically reset by using ossmix and restoring
#            defaults from /etc/ossmix.conf. This file is just a listing
#            of the parameter|value pairs that ossmix expects, on pair per
#            line, lines starting with "#" are comments. 
#   
# /etc/rc.d/init.d/sounddriver stop 
#    the currently running driver will be stopped. 
# /etc/rc.d/init.d/sounddriver restart
#    stop the current driver and restart the default

# Source function library (for RedHat).
. /etc/rc.d/init.d/functions

KERNEL=`/bin/uname -r`

# Source sound driver configuration file

if [ -f /etc/sysconfig/sounddriver ]; then
    . /etc/sysconfig/sounddriver
else
    # No configuration, figure out reasonable defaults...
    if [ -f /lib/modules/${KERNEL}/misc/snd.o ] ; then
	# ALSA is installed, first choice
	DRIVER=ALSA
    else
	if [ -d /usr/lib/oss-${KERNEL} ] ; then
	    # OSS is installed for current kernel
	    DRIVER=OSS
	fi
    fi
fi
# second argument in command line overrides choice
if [ ! "$2" = "" ] ; then
    DRIVER=$2
fi

# Support functions for ALSA driver

function alsa_start() {
    #
    # insert all alsa sound modules
    #
    cat $MODCONF | \
    grep -E "^alias( |\t)+snd-card-[[:digit:]]" | \
    awk '{print $3}' | \
    while read line; do \
      echo -n "Starting sound driver: $line "; \
      /sbin/modprobe $line; \
      echo "done"; \
    done
    # load oss/free emulation
    echo -n "Starting oss/free emulation "
    /sbin/modprobe snd-pcm-oss
    /sbin/modprobe snd-mixer-oss
    /sbin/modprobe snd-seq-oss
    /sbin/modprobe snd-seq-midi
    # make sure there's a link to sndstat
    # the file or link is erased when either
    # driver is stopped
    if [ ! -L /dev/sndstat ] ; then
	/bin/rm -f /dev/sndstat
	/bin/ln -s /proc/asound/sndstat /dev/sndstat
    fi
    echo "done"
    #
    # restore driver settings
    #
    if [ -x $ALSACTL ]; then
	$ALSACTL restore
    else
	echo "ERROR: alsactl not found"
    fi
}

function alsa_detect_stop() {
    #
    # remove all sound modules
    #
    /sbin/lsmod | grep -E "^snd" | while read line; do \
	/sbin/rmmod `echo $line | cut -d ' ' -f 1`; \
    done
    # remove the 2.2 soundcore module (if possible)
    /sbin/rmmod soundcore 2> /dev/null
}

function alsa_stop() {
    #
    # remove all sound modules
    #
    alsa_detect_stop
    # make sure there nothing left of sndstat, it is a source 
    # of problems with a mixed driver (oss/alsa) configuration
    if [ -L /dev/sndstat ] ; then
	/bin/rm -f /dev/sndstat
    fi
}

function alsa_detect_start() {
    #
    # run only detect module
    #
    /sbin/modprobe snd-detect
}

# set up defaults

MODCONF=/etc/modules.conf
ALSACTL=/usr/sbin/alsactl
if [ ! -r $MODCONF ]; then
    if [ -r /etc/conf.modules ]; then
	MODCONF=/etc/conf.modules
    fi
fi
OSSBASE=/usr/lib/oss

# See how we were called.

case "$1" in
    start)
	if [ ${DRIVER} = "ALSA" ]; then
	    #
	    # start alsa driver (humm, we should check oss is not running)
	    #
	    if [ ! -d /proc/asound ]; then
		alsa_start
		if [ -d /proc/asound ] && [ -d /var/lock/subsys ]; then
		    touch /var/lock/subsys/alsasound
		    success "ALSA sound driver load"
		    echo
		fi
	    else
		if [ -f /proc/asound/detect ]; then
		    echo -n "Shutting down sound detect module: "
		    alsa_detect_stop
		    echo "done"
		    alsa_start
		    if [ -d /proc/asound ] && [ -d /var/lock/subsys ]; then
			touch /var/lock/subsys/alsasound
			success "ALSA sound driver load"
			echo
		    fi
		else
		    echo -n "ALSA driver is already running"
		    failure "ALSA sound driver load"
		    echo
		fi
	    fi
	fi
	if [ ${DRIVER} = "OSS" ]; then
	    #
	    # start oss driver (we should check alsa is not running)
	    #
	    echo -n "Loading sound driver for kernel ${KERNEL}: "
	    if [ -d ${OSSBASE}-${KERNEL} ] ; then
		# there is an oss installation for this kernel
		if [ ! -e ${OSSBASE} -o -L ${OSSBASE} ] ; then
		    # link it to the base name
		    /bin/rm -f ${OSSBASE}
		    /bin/ln -s oss-${KERNEL} ${OSSBASE}
		fi
	    fi
	    if [ -x ${OSSBASE}-${KERNEL}/soundon ] ; then
		# make sure sndstat is not there, if left over
		# from a previous alsa start the oss script
		# gets confused and won't start...
		if [ -e /dev/sndstat ] ; then
		    rm -f /dev/sndstat
		fi
		${OSSBASE}-${KERNEL}/soundon
		if [ $? -ne 0 ] ; then
		    failure "sound driver load [$?]"
		    echo
		else
		    # initialize mixer
		    if [ -x ${OSSBASE}-${KERNEL}/ossmix ] ; then
			if [ -f /etc/ossmix.conf ] ; then
			    ${OSSBASE}-${KERNEL}/ossmix `/bin/egrep -v "^#" /etc/ossmix.conf` >/dev/null
			    echo "OSS mixer initialized"
			fi
		    fi
		    touch /var/lock/subsys/sound
		    cat /dev/sndstat | head -1
		    cat /dev/sndstat | awk 'BEGIN { RS=""} ; /config:/{ print }'
		    success "OSS sound driver load"
		    echo
		fi
	    else
		# could not find soundon for current kernel
		failure "finding ${OSSBASE}-${KERNEL}/soundon"
		echo
	    fi
	fi
	;;
  stop)
	if [ -d /proc/asound ]; then
	    #
	    # stop alsa driver
	    #
	    if [ -d /proc/asound ]; then
		echo -n "Shutting down sound driver: "
		if [ -f /proc/asound/detect ]; then
		    alsa_detect_stop
		else
		    alsa_stop
		fi
		if [ -d /var/lock/subsys ]; then
		    rm -f /var/lock/subsys/alsasound
		fi
		echo "done"
		success "ALSA sound driver stop"
		echo
	    else
		echo "ALSA driver isn't running."
		failure "ALSA sound driver stop"
		echo
	    fi
	else
	    #
	    # stop oss driver
	    #
	    echo -n "Unloading OSS sound driver: "
	    if [ -x ${OSSBASE}/soundoff ] ; then
		rm -f /var/lock/subsys/sound
		${OSSBASE}/soundoff
		# make sure there's no sndstat, if there is one
		# then the alsa drivers get loaded on the next
		# oss driver start through "cat /dev/sndstat"
		# (part of soundon) and the driver cannot restart
		# properly...
		if [ -e /dev/sndstat ] ; then
		    /bin/rm -f /dev/sndstat
		fi
		success "OSS sound driver unload"
		echo
	    else
		failure "finding ${OSSBASE}/soundoff"
		echo
	    fi
	fi
        ;;
  restart)
	$0 stop
	$0 start
	;;
  detect)
	if [ ${DRIVER} = "ALSA" ]; then
	    #
	    # start alsa driver in detect mode.
	    #
	    if [ -d /proc/asound ]; then
		if [ -f /proc/asound/detect ]; then
		    echo "ALSA driver is already running in detect mode."
		    exit 0
		else
		    echo -n "Shutting down sound driver: "
		    alsa_stop
		    echo "done"
		fi
	    fi
	    echo -n "Starting sound detect module: "
	    alsa_detect_start
	    echo "done"
	    if [ -d /var/lock/subsys ]; then
		touch /var/lock/subsys/alsasound
	    fi
	    success "ALSA detect sound driver load"
	    echo
	fi
	;;
  *)
        echo "Usage: sounddriver {start|stop|restart|detect}"
        exit 1
esac

exit 0