blob: 15ba1a49083f6b924ede7a81be301da88995ae95 [file] [log] [blame]
#!/usr/bin/perl -w
#
# Copyright (C) 2003-2006 Jean Delvare <khali@linux-fr.org>
#
# 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 of the License, 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301 USA.
#
# Version 0.1 2003-07-17 Jean Delvare <khali@linux-fr.org>
# Version 0.2 2003-07-22 Jean Delvare <khali@linux-fr.org>
# Use print instead of syswrite.
# Version 0.3 2003-08-24 Jean Delvare <khali@linux-fr.org>
# Fix data block length (128 bytes instead of 256).
# Version 1.0 2004-02-08 Jean Delvare <khali@linux-fr.org>
# Added support for Linux 2.5/2.6 (i.e. sysfs).
# Version 1.1 2006-09-01 Jean Delvare <khali@linux-fr.org>
# Append /usr/sbin or /usr/local/sbin to $PATH if needed.
#
# EEPROM data decoding for EDID. EDID (Extended Display Identification
# Data) is a VESA standard which allows storing (on manufacturer's side)
# and retrieving (on user's side) of configuration information about
# displays, such as manufacturer, serial number, physical dimensions and
# allowed horizontal and vertical refresh rates.
#
# Using the eeprom kernel driver, you have two possibilities to
# make use of these data:
# 1* The ddcmon script.
# 2* This script.
# Both solutions will return a different kind of information. The first
# method will report user-interesting information, such as the model number
# or the year of manufacturing. The second method will report video-card-
# interesting information, such as video modes and refresh rates.
#
# Note that this script does almost nothing by itself. It simply converts
# what it finds in /proc to binary data to feed the parse-edid program.
# The parse-edid program was written by John Fremlin and is available at
# the following address:
# http://john.fremlin.de/programs/linux/read-edid/
use strict;
use Fcntl qw(:DEFAULT :seek);
use vars qw($bus $address);
use constant PROCFS => 1;
use constant SYSFS => 2;
# parse-edid will typically be installed in /usr/sbin or /usr/local/sbin
# even though regular users can run it
$ENV{PATH} .= ':/usr/local/sbin'
if $ENV{PATH} !~ m,(^|:)/usr/local/sbin/?(:|$),
&& -x '/usr/local/sbin/parse-edid';
$ENV{PATH} .= ':/usr/sbin'
if $ENV{PATH} !~ m,(^|:)/usr/sbin/?(:|$),
&& -x '/usr/sbin/parse-edid';
sub edid_valid_procfs
{
my ($bus, $addr) = @_;
open EEDATA, "/proc/sys/dev/sensors/eeprom-i2c-$bus-$addr/00";
my $line = <EEDATA>;
close EEDATA;
return 1
if $line =~ m/^0 255 255 255 255 255 255 0 /;
return 0;
}
# Only used for sysfs
sub rawread
{
my ($filename, $length, $offset) = @_;
my $bytes = '';
sysopen(FH, $filename, O_RDONLY)
or die "Can't open $filename";
if ($offset)
{
sysseek(FH, $offset, SEEK_SET)
or die "Can't seek in $filename";
}
$offset = 0;
while ($length)
{
my $r = sysread(FH, $bytes, $length, $offset);
die "Can't read $filename"
unless defined($r);
die "Unexpected EOF in $filename"
unless $r;
$offset += $r;
$length -= $r;
}
close(FH);
return $bytes;
}
sub edid_valid_sysfs
{
my ($bus, $addr) = @_;
my $bytes = rawread("/sys/bus/i2c/devices/$bus-00$addr/eeprom", 8, 0);
return 1
if $bytes eq "\x00\xFF\xFF\xFF\xFF\xFF\xFF\x00";
return 0;
}
sub bus_detect
{
my $max = shift;
for (my $i=0; $i<$max; $i++)
{
if (-r "/proc/sys/dev/sensors/eeprom-i2c-$i-50/00")
{
if (edid_valid_procfs($i, '50'))
{
print STDERR
"decode-edid: using bus $i (autodetected)\n";
return $i;
}
}
elsif (-r "/sys/bus/i2c/devices/$i-0050/eeprom")
{
if (edid_valid_sysfs($i, '50'))
{
print STDERR
"decode-edid: using bus $i (autodetected)\n";
return $i;
}
}
}
return; # default
}
sub edid_decode
{
my ($bus, $addr, $mode) = @_;
# Make sure it is an EDID EEPROM.
unless (($mode == PROCFS && edid_valid_procfs ($bus, $addr))
|| ($mode == SYSFS && edid_valid_sysfs ($bus, $addr)))
{
print STDERR
"decode-edid: not an EDID EEPROM at $bus-$addr\n";
return;
}
$SIG{__WARN__} = sub { };
open PIPE, "| parse-edid"
or die "Can't open parse-edid. Please install read-edid.\n";
delete $SIG{__WARN__};
binmode PIPE;
if ($mode == PROCFS)
{
for (my $i=0; $i<=0x70; $i+=0x10)
{
my $file = sprintf '%02x', $i;
my $output = '';
open EEDATA, "/proc/sys/dev/sensors/eeprom-i2c-$bus-$addr/$file"
or die "Can't read /proc/sys/dev/sensors/eeprom-i2c-$bus-$addr/$file";
while(<EEDATA>)
{
foreach my $item (split)
{
$output .= pack "C", $item;
}
}
close EEDATA;
print PIPE $output;
}
}
elsif ($mode == SYSFS)
{
print PIPE rawread("/sys/bus/i2c/devices/$bus-00$address/eeprom", 128, 0);
}
close PIPE;
}
# Get the address. Default to 0x50 if not given.
$address = $ARGV[1] || 0x50;
# Convert to decimal, whatever the value.
$address = oct $address if $address =~ m/^0/;
# Convert to an hexadecimal string.
$address = sprintf '%02x', $address;
# Get the bus. Try to autodetect if not given.
$bus = $ARGV[0] if defined $ARGV[0];
$bus = bus_detect(8) unless defined $bus;
if(defined $bus)
{
print STDERR
"decode-edid: decode-edid version 1.1\n";
if (-r "/proc/sys/dev/sensors/eeprom-i2c-$bus-$address")
{
edid_decode ($bus, $address, PROCFS);
exit 0;
}
elsif (-r "/sys/bus/i2c/devices/$bus-00$address")
{
edid_decode ($bus, $address, SYSFS);
exit 0;
}
}
print STDERR
"EDID EEPROM not found. Please make sure that the eeprom module is loaded.\n";
print STDERR
"Maybe your EDID EEPROM is on another bus. Try \"decode-edid ".($bus+1)."\".\n"
if defined $bus;