#!/usr/bin/perl
#
# Reads /proc/bus/usb/devices and selectively lists and/or
# interprets it.
#
# Originally written by Randy Dunlap. 
#

$DEVFILENAME = "/proc/bus/usb/devices";
$PROGNAME = $0;

if (! open (DEVNUM, "<$DEVFILENAME"))
{
	print "$PROGNAME: cannot open '$DEVFILENAME'\n";
	exit 1;
}

while ($line = <DEVNUM>)	# read a text line from DEVNUM
{
	# skip all lines except those that begin with "T:", "S:", "D:" or "I:".
	if (($line !~ "^T:") && ($line !~ "^I:") && ($line !~ "^D:") && ($line !~ "^S:"))
	{
		next;	# to the next line
	}

	chomp $line;		# remove line endings

	# First convert '=' signs to spaces.
	$line =~ tr/=/ /;

	# and convert all '(' and ')' to spaces.
	$line =~ tr/(/ /;
	$line =~ tr/)/ /;

	# split the line at spaces.
	@fields = split / +/, $line;

	if ($line =~ "^T:")
	{
		# split yields: $bus, $level, $parent, $port, $count, $devnum, $speed, $maxchild.

		$bus    = @fields [2];
		$level  = @fields [4];
		$parent = @fields [6];		# parent devnum
		$port   = @fields [8] + 1;	# make $port 1-based
		$count  = @fields [10];
		$devnum = @fields [12];
		$speed  = @fields [14];
		$maxchild = @fields [16];
		$devclass = "?";
		$intclass = "?";
		$driver   = "?";
		$ifnum    = "?";
		$showclass = "?";	# derived from $devclass or $intclass
		$lastif = "?";			# show only first altsetting
		$HCtype = "?";
		next;
	} # end T: line
	elsif ($line =~ "^D:")
	{ # for D: line
		$devclass = @fields [5];
		next;
	}
	elsif ( $line =~ "^S:" )
	{ # for S: line
		if ( $level == 00 && $line =~ "hcd" )
		{
		    $HCtype = @fields [4];
		}
		elsif ( $level == 00 && $line =~ "HCI" )
		{
		    $HCtype = @fields [3];
		}
		next;
	}
	else
	{ # for I: line
		$intclass = @fields [9];
		$ifnum    = @fields [2];
		$driver   = @fields [15];
	} # end I: line

	if (($devclass eq ">ifc") || ($devclass eq "unk."))
	{	# then use InterfaceClass, not DeviceClass
		$showclass = $intclass;
		$show = "interface";
	}
	else
	{	# use DeviceClass
		$showclass = $devclass;
		$show = "device";
	}

	if ($level == 0)
	{
	    # substitute read driver name
	    if ( $HCtype =~ "UHCI-alt" )
	    {
		$HC = "uhci";
	    }
	    elsif ( $HCtype =~ "UHCI" )
	    {
		$HC = "usb-uhci";
	    }
	    elsif ( $HCtype =~ "OHCI" )
	    {
		$HC = "usb-ohci";
	    }
	    else
	    {
		$HC = $HCtype;
	    }

		print sprintf ("/:  Bus $bus.Port $port: Dev $devnum, Class=root_hub, Driver=%s/%sp, %sM\n",
			 $HC, $maxchild, $speed );
	}
	elsif ($show eq "device" || $lastif ne $ifnum)
	{
		$temp = $level;
		while ($temp >= 1)
		{
			print "    ";
			$temp--;
		}

		print sprintf ("|__ Port $port: Dev $devnum, If $ifnum, Class=$showclass, Driver=$driver%s, %sM\n",
			($maxchild == 0) ? "" : ("/" . $maxchild . "p"),
			$speed);
		$lastif = $ifnum;
	}
} # end while DEVNUM

close (DEVNUM);

# END.