busybox: implement suspend/resume SUSPEND_MODULES for systemd

packages/sysutils/busybox/config/suspend-modules.conf

@@ -0,0 +1 @@
+SUSPEND_MODULES="xhci-hcd jme asix anysee rtl8192se imon r8712u cx23885 cdc_acm"

packages/sysutils/busybox/install

@@ -48,6 +48,7 @@ USER_PWD="`$ROOT/$TOOLCHAIN/bin/cryptpw -m sha512 $USER_PASSWORD`"
     cp $PKG_DIR/config/profile $INSTALL/etc
     cp $PKG_DIR/config/inputrc $INSTALL/etc
     cp $PKG_DIR/config/httpd.conf $INSTALL/etc
+    cp $PKG_DIR/config/suspend-modules.conf $INSTALL/etc
     echo "chmod 000 $INSTALL/etc/shadow" >> $FAKEROOT_SCRIPT
 
   mkdir -p $INSTALL/usr/config/sysctl.d

packages/sysutils/busybox/sleep.d.serial/99-suspend-modules.sh

@@ -0,0 +1,99 @@
+#!/bin/sh
+################################################################################
+#      This file is part of OpenELEC - http://www.openelec.tv
+#      Copyright (C) 2009-2012 Stephan Raue (stephan@openelec.tv)
+#
+#  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, 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 OpenELEC.tv; see the file COPYING.  If not, write to
+#  the Free Software Foundation, 51 Franklin Street, Suite 500, Boston, MA 02110, USA.
+#  http://www.gnu.org/copyleft/gpl.html
+################################################################################
+
+. /etc/suspend-modules.conf
+
+modunload()
+{
+    local MOD D C USED MODS I
+    local UNL="$(echo $1 |tr - _)" RET=1
+
+    while read MOD D C USED D; do
+        [ "$MOD" = "$UNL" ] || continue
+        if [ "$USED" = "-" ]; then
+            # no dependent modules, just try to remove this one.
+            _rmmod "$MOD" $C
+            RET=$?
+        else
+            # modules depend on this one.  try to remove them first.
+            MODS=",${USED%,}"
+            while [ -n "${MODS}" ]; do
+                # try to unload the last one first
+                MOD="${MODS##*,}"
+                modunload $MOD && RET=0
+                # prune the last one from the list
+                MODS="${MODS%,*}"
+            done
+            # if we unloaded at least one module, then let's
+            # try again!
+            [ $RET -eq 0 ] && modunload $MOD
+            RET=$?
+        fi
+        return $RET
+    done < /proc/modules
+    # if we came this far, there was nothing to do,
+    # the module is no longer loaded.
+    return 0
+}
+
+_rmmod()
+{
+    if modprobe -r "$1"; then
+        touch "/run/openelec/suspend/module:$1"
+        return 0
+    else
+        logger -t suspend-modules "# could not unload '$1', usage count was $2"
+        return 1
+    fi
+}
+
+resume_modules()
+{
+    for x in /run/openelec/suspend/module:* ; do
+        [ -O "${x}" ] || continue
+        modprobe "${x##*:}" &>/dev/null && \
+            logger -t resume-modules "Reloaded module ${x##*:}." || \
+            logger -t resume-modules "Could not reload module ${x##*:}."
+    done
+}
+
+suspend_modules()
+{
+    [ -z "$SUSPEND_MODULES" ] && return 0
+    # clean up
+    rm -rf /run/openelec/suspend
+    mkdir -p /run/openelec/suspend
+    for x in $SUSPEND_MODULES ; do
+        modunload $x && \
+            logger -t suspend-modules "Unloading kernel module $x: Done" || \
+            logger -t suspend-modules "Unloading kernel module $x: Failed"
+    done
+    return 0
+}
+
+case $1 in
+    pre)
+        suspend_modules
+    ;;
+    post)
+        resume_modules
+    ;;
+esac