dahdi-modules: load and unloads the modules

A script that performs the module loading / unloading instead of the
init script.

Other functionality of the init script is performed by udev hooks. But
manual initiation of modules loading or unloading is still needed on
several occasions.

This script should help enable the removal of the init script from the
DAHDI package.

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>

dahdi-modules

@@ -0,0 +1,72 @@
+#!/bin/sh
+
+MODULES="dahdi"
+DAHDI_MODULES_FILE="/etc/dahdi/modules"
+
+usage() {
+	cat <<EOF
+$0: loads / unloads DAHDI kernel modules
+
+Usage: $0 <load|unload>
+
+* load: Loads all modules listed in /etc/dahdi/modules (one per line)
+* unload: Unloads the DAHDI modules (all the modules that are dependencies
+  of $MODULES).
+EOF
+}
+
+# recursively unload a module and its dependencies, if possible.
+# where's modprobe -r when you need it?
+# inputs: module to unload.
+# returns: the result from
+unload_module() {
+	module="$1"
+	line=`lsmod 2>/dev/null | grep "^$1 "`
+	if [ "$line" = '' ]; then return; fi # module was not loaded
+
+	set -- $line
+	# $1: the original module, $2: size, $3: refcount, $4: deps list
+	mods=`echo $4 | tr , ' '`
+	ec_modules=""
+	# xpp_usb keeps the xpds below busy if an xpp hardware is
+	# connected. Hence must be removed before them:
+	case "$module" in xpd_*) mods="xpp_usb $mods";; esac
+
+	for mod in $mods; do
+		case "$mod" in
+		dahdi_echocan_*)
+			ec_modules="$mod $ec_modules"
+			;;
+		*)
+			# run in a subshell, so it won't step over our vars:
+			(unload_module $mod)
+			;;
+		esac
+	done
+	# Now that all the other dependencies are unloaded, we can unload the
+	# dahdi_echocan modules.  The drivers that register spans may keep
+	# references on the echocan modules before they are unloaded.
+	for mod in $ec_modules; do
+		(unload_module $mod)
+	done
+	rmmod $module
+}
+
+unload_modules() {
+	for module in "$@"; do
+		unload_module $module
+	done
+}
+
+load_modules() {
+	modules=`sed -e 's/#.*$//' $DAHDI_MODULES_FILE 2>/dev/null`
+	for line in $modules; do
+		modprobe $line
+	done
+}
+
+case "$1" in
+	load) load_modules "$@";;
+	unload) unload_modules $MODULES;;
+	*) usage;;
+esac