File indexing completed on 2025-04-27 11:33:52

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2015 Martin Flöser <mgraesslin@kde.org>
     SPDX-FileCopyrightText: 2019 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "edid.h"
 
 #include "config-kwin.h"
 
 #include <QFile>
 #include <QStandardPaths>
 
 #include <KLocalizedString>
 
 namespace KWin
 {
 
 static bool verifyHeader(const uint8_t *data)
 {
     if (data[0] != 0x0 || data[7] != 0x0) {
         return false;
     }
 
     return std::all_of(data + 1, data + 7,
                        [](uint8_t byte) {
                            return byte == 0xff;
                        });
 }
 
 static QSize parsePhysicalSize(const uint8_t *data)
 {
     // Convert physical size from centimeters to millimeters.
     return QSize(data[0x15], data[0x16]) * 10;
 }
 
 static QByteArray parsePnpId(const uint8_t *data)
 {
     // Decode PNP ID from three 5 bit words packed into 2 bytes:
     //
     // | Byte |        Bit                    |
     // |      | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
     // ----------------------------------------
     // |  1   | 0)| (4| 3 | 2 | 1 | 0)| (4| 3 |
     // |      | * |    Character 1    | Char 2|
     // ----------------------------------------
     // |  2   | 2 | 1 | 0)| (4| 3 | 2 | 1 | 0)|
     // |      | Character2|      Character 3  |
     // ----------------------------------------
     const uint offset = 0x8;
 
     char pnpId[4];
     pnpId[0] = 'A' + ((data[offset + 0] >> 2) & 0x1f) - 1;
     pnpId[1] = 'A' + (((data[offset + 0] & 0x3) << 3) | ((data[offset + 1] >> 5) & 0x7)) - 1;
     pnpId[2] = 'A' + (data[offset + 1] & 0x1f) - 1;
     pnpId[3] = '\0';
 
     return QByteArray(pnpId);
 }
 
 static QByteArray parseEisaId(const uint8_t *data)
 {
     for (int i = 72; i <= 108; i += 18) {
         // Skip the block if it isn't used as monitor descriptor.
         if (data[i]) {
             continue;
         }
         if (data[i + 1]) {
             continue;
         }
 
         // We have found the EISA ID, it's stored as ASCII.
         if (data[i + 3] == 0xfe) {
             return QByteArray(reinterpret_cast<const char *>(&data[i + 5]), 13).trimmed();
         }
     }
 
     // If there isn't an ASCII EISA ID descriptor, try to decode PNP ID
     return parsePnpId(data);
 }
 
 static QByteArray parseMonitorName(const uint8_t *data)
 {
     for (int i = 72; i <= 108; i += 18) {
         // Skip the block if it isn't used as monitor descriptor.
         if (data[i]) {
             continue;
         }
         if (data[i + 1]) {
             continue;
         }
 
         // We have found the monitor name, it's stored as ASCII.
         if (data[i + 3] == 0xfc) {
             return QByteArray(reinterpret_cast<const char *>(&data[i + 5]), 13).trimmed();
         }
     }
 
     return QByteArray();
 }
 
 static QByteArray parseSerialNumber(const uint8_t *data)
 {
     for (int i = 72; i <= 108; i += 18) {
         // Skip the block if it isn't used as monitor descriptor.
         if (data[i]) {
             continue;
         }
         if (data[i + 1]) {
             continue;
         }
 
         // We have found the serial number, it's stored as ASCII.
         if (data[i + 3] == 0xff) {
             return QByteArray(reinterpret_cast<const char *>(&data[i + 5]), 13).trimmed();
         }
     }
 
     // Maybe there isn't an ASCII serial number descriptor, so use this instead.
     const uint32_t offset = 0xc;
 
     uint32_t serialNumber = data[offset + 0];
     serialNumber |= uint32_t(data[offset + 1]) << 8;
     serialNumber |= uint32_t(data[offset + 2]) << 16;
     serialNumber |= uint32_t(data[offset + 3]) << 24;
     if (serialNumber) {
         return QByteArray::number(serialNumber);
     }
 
     return QByteArray();
 }
 
 static QByteArray parseVendor(const uint8_t *data)
 {
     const auto pnpId = parsePnpId(data);
 
     // Map to vendor name
     QFile pnpFile(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("hwdata/pnp.ids")));
     if (pnpFile.exists() && pnpFile.open(QIODevice::ReadOnly)) {
         while (!pnpFile.atEnd()) {
             const auto line = pnpFile.readLine();
             if (line.startsWith(pnpId)) {
                 return line.mid(4).trimmed();
             }
         }
     }
 
     return {};
 }
 
 Edid::Edid()
 {
 }
 
 Edid::Edid(const void *data, uint32_t size)
 {
     m_raw.resize(size);
     memcpy(m_raw.data(), data, size);
 
     const uint8_t *bytes = static_cast<const uint8_t *>(data);
 
     if (size < 128) {
         return;
     }
 
     if (!verifyHeader(bytes)) {
         return;
     }
 
     m_physicalSize = parsePhysicalSize(bytes);
     m_eisaId = parseEisaId(bytes);
     m_monitorName = parseMonitorName(bytes);
     m_serialNumber = parseSerialNumber(bytes);
     m_vendor = parseVendor(bytes);
 
     m_isValid = true;
 }
 
 bool Edid::isValid() const
 {
     return m_isValid;
 }
 
 QSize Edid::physicalSize() const
 {
     return m_physicalSize;
 }
 
 QByteArray Edid::eisaId() const
 {
     return m_eisaId;
 }
 
 QByteArray Edid::monitorName() const
 {
     return m_monitorName;
 }
 
 QByteArray Edid::serialNumber() const
 {
     return m_serialNumber;
 }
 
 QByteArray Edid::vendor() const
 {
     return m_vendor;
 }
 
 QByteArray Edid::raw() const
 {
     return m_raw;
 }
 
 QString Edid::manufacturerString() const
 {
     QString manufacturer;
     if (!m_vendor.isEmpty()) {
         manufacturer = QString::fromLatin1(m_vendor);
     } else if (!m_eisaId.isEmpty()) {
         manufacturer = QString::fromLatin1(m_eisaId);
     }
     return manufacturer;
 }
 
 QString Edid::nameString() const
 {
     if (!m_monitorName.isEmpty()) {
         QString m = QString::fromLatin1(m_monitorName);
         if (!m_serialNumber.isEmpty()) {
             m.append('/');
             m.append(QString::fromLatin1(m_serialNumber));
         }
         return m;
     } else if (!m_serialNumber.isEmpty()) {
         return QString::fromLatin1(m_serialNumber);
     } else {
         return i18n("unknown");
     }
 }
 
 } // namespace KWin