#!/usr/bin/perl -w
#
# Copyright (C) 2002-2020  Jean Delvare <jdelvare@suse.de>
#
#    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.
#
# EEPROM data decoding for Sony Vaio laptops.
#
# The at24 or eeprom driver must be loaded. For kernels older than 2.6.0, the
# eeprom driver can be found in the lm-sensors package.
#
# Please note that this is a guess-only work.  Sony support refused to help
# me, so if someone can provide information, please contact me.
# My knowledge is summarized on this page:
# http://jdelvare.nerim.net/articles/vaio/eeprom.html
#
# It seems that if present, the EEPROM is always at 0x57.
#
# Models tested so far:
#   PCG-F403     : No EEPROM
#   PCG-F707     : No EEPROM
#   PCG-GR114EK  : OK
#   PCG-GR114SK  : OK
#   PCG-GR214EP  : OK
#   PCG-GRT955MP : OK
#   PCG-GRX316G  : OK
#   PCG-GRX570   : OK
#   PCG-GRX600K  : OK
#   PCG-U1       : OK
#   PCG-Z600LEK  : No EEPROM
#   PCG-Z600NE   : No EEPROM
#   VGN-S260     : OK
#   VGN-S4M/S    : OK
#   VGN-TZ11MN/N : OK
#
# Thanks to Werner Heuser, Carsten Blume, Christian Gennerat, Joe Wreschnig,
# Xavier Roche, Sebastien Lefevre, Lars Heer, Steve Dobson, Kent Hunt,
# Timo Hoenig and others for their precious help.


use strict;
use Fcntl qw(:DEFAULT :seek);
use File::Basename;
use vars qw($sysfs $found);

use constant VERSION	=> "1.7";
use constant ONLYROOT	=> "Readable only by root";

# From a sysfs device path and an attribute name, return the attribute
# value, or undef (stolen from sensors-detect)
sub sysfs_device_attribute
{
	my ($device, $attr) = @_;
	my $value;

	open(local *FILE, "$device/$attr") or return "";
	$value = <FILE>;
	close(FILE);
	return unless defined $value;

	chomp($value);
	return $value;
}

# From a sysfs device path, return the driver name, or undef (stolen from
# sensors-detect)
sub sysfs_device_driver
{
	my $device = shift;

	my $link = readlink("$device/driver");
	return unless defined $link;
	return basename($link);
}

sub print_item
{
	my ($label,$value) = @_;

	printf("\%16s : \%s\n",$label,$value);
}

# Abstract reads so that other functions don't have to care wether
# we need to use procfs or sysfs
sub read_eeprom_bytes
{
	my ($bus, $addr, $offset, $length) = @_;
	my $filename;

	if ($sysfs)
	{
		$filename = "/sys/bus/i2c/devices/$bus-00$addr/eeprom";
		sysopen(FH, $filename, O_RDONLY)
			or die "Can't open $filename";
		sysseek(FH, $offset, SEEK_SET)
			or die "Can't seek in $filename";

		my ($r, $bytes);
		$bytes = '';
		$offset = 0;
		while($length)
		{
			$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;
	}
	else
	{
		my $base = $offset & 0xf0;
		$offset -= $base;
		my $values = '';
		my $remains = $length + $offset;

		# Get all lines in a single string
		while ($remains > 0)
		{
			$filename = "/proc/sys/dev/sensors/eeprom-i2c-$bus-$addr/"
			          . sprintf('%02x', $base);
			open(FH, $filename)
				or die "Can't open $filename";
			$values .= <FH>;
			close(FH);
			$remains -= 16;
			$base += 16;
		}

		# Store the useful part in an array
		my @bytes = split(/[ \n]/, $values);
		@bytes = @bytes[$offset..$offset+$length-1];

		# Back to a binary string
		return pack('C*', @bytes);
	}
}

sub decode_string
{
	my ($bus, $addr, $offset, $length) = @_;

	my $string = read_eeprom_bytes($bus, $addr, $offset, $length);
	$string =~ s/\x00.*$//;

	return($string);
}

sub decode_hexa
{
	my ($bus, $addr, $offset, $length) = @_;

	my @bytes = unpack('C*', read_eeprom_bytes($bus, $addr, $offset, $length));
	my $string='';

	for(my $i=0;$i<$length;$i++)
	{
		$string.=sprintf('%02X', shift(@bytes));
	}

	return($string);
}

sub decode_uuid
{
	my ($bus,$addr,$base) = @_;

	my @bytes = unpack('C16', read_eeprom_bytes($bus, $addr, $base, 16));
	my $string='';

	for(my $i=0;$i<16;$i++)
	{
		$string.=sprintf('%02x',shift(@bytes));
		if(($i==3)||($i==5)||($i==7)||($i==9))
		{
			$string.='-';
		}
	}

	if ($string eq '00000000-0000-0000-0000-000000000000')
	{
		return(ONLYROOT);
	}
	else
	{
		return($string);
	}
}

sub vaio_decode
{
	my ($bus,$addr) = @_;

	my $name = decode_string($bus, $addr, 128, 32);
	# Simple heuristic to skip false positives
	return 0 unless $name =~ m/^[A-Z-]{4}/;

	print_item('Machine Name', $name);
	my $serial = decode_string($bus, $addr, 192, 32);
	print_item('Serial Number', $serial ? $serial : ONLYROOT);
	print_item('UUID', decode_uuid($bus, $addr, 16));
	my $revision = decode_string($bus, $addr, 160, 10);
	print_item(length($revision) > 2 ? 'Service Tag' : 'Revision',
		   $revision);
	print_item('Asset Tag', decode_string($bus, $addr, 170, 4).
				decode_hexa($bus, $addr, 174, 12));
	print_item('OEM Data', decode_string($bus, $addr, 32, 16));
	print_item('Timestamp', decode_string($bus, $addr, 224, 18));
	return 1;
}

BEGIN
{
	print("# Sony Vaio EEPROM Decoder version ".VERSION." by Jean Delvare\n\n");
}

END
{
	print("\n");
}

for (my $i = 0, $found=0; $i <= 31 && !$found; $i++)
{
	if (-r "/sys/bus/i2c/devices/$i-0057/eeprom")
	{
		my $driver = sysfs_device_driver("/sys/bus/i2c/devices/$i-0057");
		my $name = sysfs_device_attribute("/sys/bus/i2c/devices/$i-0057", "name");
		next unless ($driver eq "at24" || $driver eq "eeprom");
		next if ($driver eq "at24" && $name ne "24c02-vaio");

		$sysfs = 1;
		$found += vaio_decode($i, '57');
	}
	elsif (-r "/proc/sys/dev/sensors/eeprom-i2c-$i-57")
	{
		if (-r "/proc/sys/dev/sensors/eeprom-i2c-$i-57/data0-15")
		{
			print("Deprecated old interface found.  Please upgrade to lm_sensors 2.6.3 or greater.");
			exit;
		}
		else
		{
			$sysfs = 0;
			$found += vaio_decode($i, '57');
		}
	}
}

if (!$found)
{
	print("Vaio EEPROM not found.  Please make sure that the at24 or eeprom module is loaded.\n");
}
