#!/usr/bin/perl

use Fcntl;
use POSIX qw(:termios_h);

sub indent
{
    my($str) = @_;
    $str =~ s/\n\s*(.)/\n  \1/g;
    $str =~ s/^\s*//;
    return "  $str";
}

sub init_tty
{
    # Initialize the tty device to a sane mode
    my $fd = fileno(MODEM);
    $term = POSIX::Termios->new();
    $term->getattr($fd);
    $term->setcc(VTIME, 0);
    $term->setcc(VMIN, 0);
    $term->setoflag(0);
    $term->setlflag(0);
    my $cflag = $term->getcflag | CLOCAL | CREAD | CS8;
    $cflag &= ~(CSIZE | CSTOPB | PARENB);
    $term->setcflag($cflag);
    $term->setiflag(IGNBRK | IGNPAR);
    $term->setattr($fd, TCSANOW);
}

sub at_cmd
{
    my($cmd) = @_;
    my($rin, $n, $nf, $char, $buf);
    syswrite(MODEM, "$cmd\r") || die "syswrite(): $!\n";
    $rin = $buf = '';
    $nr = 0;
    while ($nr < 1024) {
	vec($rin,fileno(MODEM),1) = 1;
	last if (!select $rin, undef, undef, 1);
	$nr += sysread(MODEM, $buf, 1024-$nr, $nr);
    }
    $buf =~ s/^\s*$cmd\s+//;
    $buf =~ s/\s+OK\s+$//;
    $buf =~ s/\s+/ /g;
    return $buf;
}

sub checkout
{
    my($dev) = @_;
    print "Checking modem at /dev/$dev:\n";
    $set = `setserial /dev/$dev`;
    print "  Settings: $set";
    if (($set =~ /8250/) || ($set =~ /16450/)) {
	print "    The detected UART is odd: maybe an IO port conflict?\n";
    }
    $irq = $1 if $set =~ /IRQ: (\d+)/;
    sysopen(MODEM, "/dev/$dev", O_RDWR|O_NONBLOCK) ||
	die "sysopen(): $!\n";
    init_tty();

    print "  Sending modem query command...\n";
    $buf = at_cmd("ATI3");
    if ($buf ne "") {
	print "    ATI3 = '$buf'\n";
	print "  The modem is operating normally.\n";
	close(MODEM);
    } else {
	close(MODEM);
	print "  Modem query timed out: trying polled mode...\n";
	system("setserial /dev/$dev irq 0");
	sysopen(MODEM, "/dev/$dev", O_RDWR|O_NONBLOCK) ||
	    die "sysopen(): $!\n";
	$buf = at_cmd("ATI3");
	if ($buf ne "") {
	    print "    ATI3 = '$buf'\n";
	    print "  The modem interrupt (irq $irq) has a delivery problem.\n";
	} else {
	    print "  The modem is not working in polled mode.\n";
	}
	close(MODEM);
	system("setserial /dev/$dev irq $irq");
    }
}

foreach $f ("/var/state/pcmcia/stab", "/var/lib/pcmcia/stab",
	    "/var/run/stab") {
    if (-f $f) {
	$stab = $f; last;
    }
}
if (!$stab) {
    print "Socket status file (stab) not found!  Is PCMCIA running??\n";
    exit 1;
}

$ns = 0;
open(IN, $stab);
while ($_ = <IN>) {
    chop;
    if (/^Socket (\d+): (.*)/) {
	($sock,$card) = ($1,$2);
    } else {
	@f = split;
	next if ($f[1] ne "serial");
	$ns++;
	checkout($f[4]);
    }
}
close(IN);

exit 0 if ($ns);

print "No PCMCIA modem devices are configured.\n";

open(IN, "/sbin/cardctl ident |");
while (<IN>) {
    $sock = $1 if (/^Socket (\d+)/);
    if (/function: 2/) {
	$ns++;
	print "\nThere is a serial device in socket $sock.\n";
    }
}
close(IN);

$log = `dmesg | grep register_serial | tail -2`;
print "\nKernel messages:\n", indent($log) if ($log);