#!/bin/sh
#
# originating from http://blog.stuart.shelton.me/archives/891
# slightly corrected and adapted to our needs by kristov
#

LOGFILE="kmsg"
USBDEVICES="/var/run/usb.devices"

echo >>"$LOGFILE" "$$ mdev usb helper started as '$0' in '$( pwd )', MDEV '$MDEV', ACTION '$ACTION', DEVPATH '$DEVPATH', SUBSYSTEM '$SUBSYSTEM'"

[ -n "$MDEV" ] || exit 0
[ -n "$DEVPATH" ] || exit 0
[ "$SUBSYSTEM" = "usb" ] || exit 0

# add zeros to device or bus
add_zeros() {
        case "${#1}" in
                1)      echo "00$1"
                        ;;
                2)      echo "0$1"
                        ;;
                *)      echo "$1"
                        ;;
        esac
}

# e.g. DEVPATH=/devices/pci0000:00/0000:00:0f.4/usb2/2-1, MDEV=2-1
case "$ACTION" in
        add|"")
                echo >>"$LOGFILE" "$$ Performing 'add' ACTION"

                BUS="$( add_zeros "$( cat "/sys$DEVPATH/busnum" 2>/dev/null )" )"
                USB_DEV="$( add_zeros "$( cat "/sys$DEVPATH/devnum" 2>/dev/null )" )"

                # move usb device file
                prefix="bus/usb/$BUS"
                mv "$MDEV" "$prefix/$USB_DEV" \
                        && echo >>"$LOGFILE" "$$ mv succeeded for '$prefix/$USB_DEV'" \
                        || { echo >>"$LOGFILE" "$$ mv failed for '$prefix/$USB_DEV'" ; exit 0 ; }
                echo "$DEVPATH $BUS $USB_DEV" >> "$USBDEVICES"
                ;;
        remove)
                echo >>"$LOGFILE" "$$ Performing 'remove' ACTION"

                # remove device file and possible empty dirs
                set -- $(grep "^$DEVPATH\>" "$USBDEVICES" 2>/dev/null)
                if [ -z "$2" -o -z "$3" ]
                then
                    echo >>"$LOGFILE" "$$ Cannot find device node for $DEVPATH"
                    exit 0
                else
                    BUS=$2
                    USB_DEV=$3
                    sed -i -e "/^$(echo $DEVPATH | sed -e 's,/,\\/,g')\>/d" "$USBDEVICES"
                fi

                prefix="bus/usb/$BUS"
                if rm -f "$prefix/$USB_DEV" 2>/dev/null \
                        && echo >>"$LOGFILE" "$$ rm -f '$prefix/$USB_DEV' succeeded"
                then
                        if ! ls -1 "$prefix"/* >/dev/null 2>&1
                        then
                                rm -rf "$prefix" 2>/dev/null \
                                        && echo >>"$LOGFILE" "$$ rm -rf '$prefix' succeeded" \
                                        || { echo >>"$LOGFILE" "$$ rm -rf '$prefix' failed" ; exit 0 ; }
                        else
                                echo >>"$LOGFILE" "$$ Don't removing non-empty $prefix"
                        fi
                else
                        echo >>"$LOGFILE" "$$ rm -f '$prefix/$USB_DEV' failed"
                        exit 0
                fi
                ;;
esac

echo >>"$LOGFILE" "$$ mdev usb helper completed successfully"

exit 0