src/lib/edid.cc

   1 /*
   2     Copyright (C) 2018 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     DCP-o-matic is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 #include "compose.hpp"
  22 #include "edid.h"
  23 #include <dcp/raw_convert.h>
  24 #include <libxml++/libxml++.h>
  25 #include <boost/filesystem.hpp>
  26 #include <boost/algorithm/string.hpp>
  27 #include <iostream>
  28
  29 #define EDID_SYS_PATH "/sys/class/drm"
  30 static uint8_t const edid_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 };
  31
  32 using std::vector;
  33 using std::string;
  34 using std::cout;
  35
  36 vector<Monitor>
  37 get_monitors()
  38 {
  39         using namespace boost::filesystem;
  40         using namespace boost::algorithm;
  41
  42         vector<Monitor> monitors;
  43
  44         int card = 0;
  45         while (true) {
  46                 path card_dir = String::compose("%1/card%2", EDID_SYS_PATH, card);
  47                 if (!is_directory(card_dir)) {
  48                         break;
  49                 }
  50
  51                 for (directory_iterator i = directory_iterator(card_dir); i != directory_iterator(); ++i) {
  52                         if (!starts_with(i->path().filename().string(), String::compose("card%1", card))) {
  53                                 continue;
  54                         }
  55
  56                         FILE* edid_file = fopen(path(i->path() / "edid").string().c_str(), "r");
  57                         if (!edid_file) {
  58                                 continue;
  59                         }
  60
  61                         uint8_t edid[128];
  62                         int const N = fread(edid, 1, sizeof(edid), edid_file);
  63                         fclose(edid_file);
  64                         if (N != 128) {
  65                                 continue;
  66                         }
  67
  68                         if (memcmp(edid, edid_header, 8) != 0) {
  69                                 continue;
  70                         }
  71
  72                         Monitor mon;
  73
  74                         uint16_t mid = (edid[8] << 8) | edid[9];
  75                         mon.manufacturer_id += char(((mid >> 10) & 0x1f) + 'A' - 1);
  76                         mon.manufacturer_id += char(((mid >> 5) & 0x1f) + 'A' - 1);
  77                         mon.manufacturer_id += char(((mid >> 0) & 0x1f) + 'A' - 1);
  78
  79                         mon.manufacturer_product_code = (edid[11] << 8) | edid[10];
  80
  81                         mon.serial_number = (edid[15] << 24) | (edid[14] << 16) | (edid[13] << 8) | edid[12];
  82                         mon.week_of_manufacture = edid[16];
  83                         mon.year_of_manufacture = edid[17];
  84                         monitors.push_back (mon);
  85                 }
  86
  87                 ++card;
  88         }
  89
  90         return monitors;
  91 }
  92
  93 Monitor::Monitor ()
  94         : manufacturer_product_code (0)
  95         , serial_number (0)
  96         , week_of_manufacture (0)
  97         , year_of_manufacture (0)
  98 {
  99
 100 }
 101
 102 Monitor::Monitor (cxml::ConstNodePtr node)
 103         : manufacturer_id(node->string_child("ManufacturerId"))
 104         , manufacturer_product_code(node->number_child<uint32_t>("ManufacturerProductCode"))
 105         , serial_number(node->number_child<uint32_t>("SerialNumber"))
 106         , week_of_manufacture(node->number_child<int>("WeekOfManufacture"))
 107         , year_of_manufacture(node->number_child<int>("YearOfManufacture"))
 108
 109 {
 110
 111 }
 112
 113 void
 114 Monitor::as_xml (xmlpp::Node* parent) const
 115 {
 116         parent->add_child("ManufacturerId")->add_child_text(manufacturer_id);
 117         parent->add_child("ManufacturerProductCode")->add_child_text(dcp::raw_convert<string>(manufacturer_product_code));
 118         parent->add_child("SerialNumber")->add_child_text(dcp::raw_convert<string>(serial_number));
 119         parent->add_child("WeekOfManufacture")->add_child_text(dcp::raw_convert<string>(week_of_manufacture));
 120         parent->add_child("YearOfManufacture")->add_child_text(dcp::raw_convert<string>(year_of_manufacture));
 121 }
 122
 123 bool
 124 operator== (Monitor const & a, Monitor const & b)
 125 {
 126         return a.manufacturer_id == b.manufacturer_id &&
 127                 a.manufacturer_product_code == b.manufacturer_product_code &&
 128                 a.serial_number == b.serial_number &&
 129                 a.week_of_manufacture == b.week_of_manufacture &&
 130                 a.year_of_manufacture == b.year_of_manufacture;
 131 }