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 "warnings.h"
  24 #include <dcp/raw_convert.h>
  25 DCPOMATIC_DISABLE_WARNINGS
  26 #include <libxml++/libxml++.h>
  27 DCPOMATIC_ENABLE_WARNINGS
  28 #include <boost/filesystem.hpp>
  29 #include <boost/algorithm/string.hpp>
  30 #include <iostream>
  31
  32 #define EDID_SYS_PATH "/sys/class/drm"
  33 static uint8_t const edid_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 };
  34
  35 using std::vector;
  36 using std::string;
  37 using std::cout;
  38
  39 vector<Monitor>
  40 get_monitors()
  41 {
  42         using namespace boost::filesystem;
  43         using namespace boost::algorithm;
  44
  45         vector<Monitor> monitors;
  46
  47         int card = 0;
  48         while (true) {
  49                 path card_dir = String::compose("%1/card%2", EDID_SYS_PATH, card);
  50                 if (!is_directory(card_dir)) {
  51                         break;
  52                 }
  53
  54                 for (directory_iterator i = directory_iterator(card_dir); i != directory_iterator(); ++i) {
  55                         if (!starts_with(i->path().filename().string(), String::compose("card%1", card))) {
  56                                 continue;
  57                         }
  58
  59                         FILE* edid_file = fopen(path(i->path() / "edid").string().c_str(), "r");
  60                         if (!edid_file) {
  61                                 continue;
  62                         }
  63
  64                         uint8_t edid[128];
  65                         int const N = fread(edid, 1, sizeof(edid), edid_file);
  66                         fclose(edid_file);
  67                         if (N != 128) {
  68                                 continue;
  69                         }
  70
  71                         if (memcmp(edid, edid_header, 8) != 0) {
  72                                 continue;
  73                         }
  74
  75                         Monitor mon;
  76
  77                         uint16_t mid = (edid[8] << 8) | edid[9];
  78                         mon.manufacturer_id += char(((mid >> 10) & 0x1f) + 'A' - 1);
  79                         mon.manufacturer_id += char(((mid >> 5) & 0x1f) + 'A' - 1);
  80                         mon.manufacturer_id += char(((mid >> 0) & 0x1f) + 'A' - 1);
  81
  82                         mon.manufacturer_product_code = (edid[11] << 8) | edid[10];
  83
  84                         mon.serial_number = (edid[15] << 24) | (edid[14] << 16) | (edid[13] << 8) | edid[12];
  85                         mon.week_of_manufacture = edid[16];
  86                         mon.year_of_manufacture = edid[17];
  87                         monitors.push_back (mon);
  88                 }
  89
  90                 ++card;
  91         }
  92
  93         return monitors;
  94 }
  95
  96 Monitor::Monitor ()
  97         : manufacturer_product_code (0)
  98         , serial_number (0)
  99         , week_of_manufacture (0)
 100         , year_of_manufacture (0)
 101 {
 102
 103 }
 104
 105 Monitor::Monitor (cxml::ConstNodePtr node)
 106         : manufacturer_id(node->string_child("ManufacturerId"))
 107         , manufacturer_product_code(node->number_child<uint32_t>("ManufacturerProductCode"))
 108         , serial_number(node->number_child<uint32_t>("SerialNumber"))
 109         , week_of_manufacture(node->number_child<int>("WeekOfManufacture"))
 110         , year_of_manufacture(node->number_child<int>("YearOfManufacture"))
 111
 112 {
 113
 114 }
 115
 116 void
 117 Monitor::as_xml (xmlpp::Node* parent) const
 118 {
 119         parent->add_child("ManufacturerId")->add_child_text(manufacturer_id);
 120         parent->add_child("ManufacturerProductCode")->add_child_text(dcp::raw_convert<string>(manufacturer_product_code));
 121         parent->add_child("SerialNumber")->add_child_text(dcp::raw_convert<string>(serial_number));
 122         parent->add_child("WeekOfManufacture")->add_child_text(dcp::raw_convert<string>(week_of_manufacture));
 123         parent->add_child("YearOfManufacture")->add_child_text(dcp::raw_convert<string>(year_of_manufacture));
 124 }
 125
 126 bool
 127 operator== (Monitor const & a, Monitor const & b)
 128 {
 129         return a.manufacturer_id == b.manufacturer_id &&
 130                 a.manufacturer_product_code == b.manufacturer_product_code &&
 131                 a.serial_number == b.serial_number &&
 132                 a.week_of_manufacture == b.week_of_manufacture &&
 133                 a.year_of_manufacture == b.year_of_manufacture;
 134 }