#!/bin/sh
#
# Script for creating aliases for USB serial devices.  It will create
# either /dev/{tty,cu}.<serialnumber> or /dev/{tty,cu}.usb.<path> if
# there is no serial number for the device.  A path starts w/ the
# USB bus number, and then continues w/ each hub's port number.  For
# example: 2.1.4.1.4 means USB bus number 2, port 1 on root hub, port 4
# on next hub, port 1 on next hub, and port 4 on the last hub.
#
# You can use `usbserialsn discover <devname>` to get the path that a
# device is at.  It will echo the device name followed by the path.
#
#
# Add the following to /usr/local/etc/devd/usbserialsn.conf:
# attach 100 {
#         device-name             ".*";
#         match "ttyname"         ".+";
#         match "ugen"            ".+";
#         match "sernum"          ".+";
#         action "/usr/local/libexec/usbserialsn attach $device-name $sernum $ttyname";
# };
# 
# attach 100 {
#         device-name             ".*";
#         match "ttyname"         ".+";
#         match "ugen"            ".+";
#         match "sernum"          "^$";
#         action "/usr/local/libexec/usbserialsn attach $device-name auto $ttyname";
# };
# 
# detach 100 {
#         device-name             ".*";
#         action "/usr/local/libexec/usbserialsn detach $device-name";
# };
#

if [ $# -lt 2 ]; then
  echo "Usage: $0 discover <devname>"
  echo "       $0 attach <devname> <sernum>|auto <ttyname>"
  echo "       $0 detach <devname>"
  exit 1
fi

mode=$1
devname=$2
sernum=$3
ttyname=$4

getdevpath()
{
	echo $(devinfo -v | awk '
BEGIN {
	#print "start"
}

$0 ~ /bus=/ && $0 ~ /vendor=/ {
	# XXX - does not handle quoted strings
	#print
	mode = "dev"
	for (i = 3; i <= NF; i++) {
		if ($i == "at") {
			mode = "bus"
			continue
		}

		cnt = split($i, info, "=")
		if (cnt != 2)
			print "error: " cnt " " $i

		pnpinfo[$1, mode, info[1]] = info[2]
	}

	# create index of devices by: bus, devaddr.
	addrs[pnpinfo[$1, "bus", "bus"], pnpinfo[$1, "bus", "devaddr"]] = $1

	devices[$1] = 1
}

function devpath(ndev, hubaddr, portinfo) {
	hubaddr = 0
	portinfo = ""

	bus = pnpinfo[ndev, "bus", "bus"]
	while (hubaddr != 1) {
		hubaddr = pnpinfo[ndev, "bus", "hubaddr"]
		portinfo = "." pnpinfo[ndev, "bus", "port"] portinfo
		ndev = addrs[bus, hubaddr]
	}
	return bus portinfo
}

END {
	if (!devices[DEV]) {
		print "bogus"
		exit 0
	}
	print devpath(DEV)
}
'	"DEV=$1")
}

if [ x"$sernum" = x"auto" ]; then
	sernum=usb.$(getdevpath "$devname")
fi

case "$mode" in
  discover)
    echo "$devname" $(getdevpath "$devname")
    ;;

  attach)
    if [ $# -ne 4 ]; then
      echo "Bad usage"
      exit 1
    fi
    ln -sf cua${ttyname} /dev/cu.${sernum}
    ln -sf tty${ttyname} /dev/tty.${sernum}
    echo ${sernum} >/var/run/usbserialsn.${devname}
    ;;

  detach)
    if [ $# -ne 2 ]; then
      echo "Bad usage"
      exit 1
    fi
    if [ ! -e /var/run/usbserialsn.${devname} ]; then
      exit 0
    fi
    sernum=$(cat /var/run/usbserialsn.${devname})
    rm -f /dev/cu.${sernum} /dev/tty.${sernum} /var/run/usbserialsn.${devname}
    ;;

  *)
    echo "Unknown mode"
    exit 1
    ;;
esac