kwin/src/utils/edid.cpp

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/*
KWin - the KDE window manager
This file is part of the KDE project.
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SPDX-FileCopyrightText: 2015 Martin Flöser <mgraesslin@kde.org>
SPDX-FileCopyrightText: 2019 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
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SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "edid.h"
#include "config-kwin.h"
#include <QFile>
#include <QStandardPaths>
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#include <KLocalizedString>
#include <QCryptographicHash>
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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);
QCryptographicHash hash(QCryptographicHash::Md5);
hash.addData(m_raw);
m_hash = QString::fromLatin1(hash.result().toHex());
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;
}
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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");
}
}
QString Edid::hash() const
{
return m_hash;
}
} // namespace KWin