Differential D22211 Diff 61019 plugins/platforms/drm/edid.cpp

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plugins/platforms/drm/edid.cpp

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1​/********************************************************************
2​ KWin - the KDE window manager
3​ This file is part of the KDE project.
4​
5​Copyright (C) 2015 Martin Flöser <mgraesslin@kde.org>
6​Copyright (C) 2019 Vlad Zagorodniy <vladzzag@gmail.com>
7​
8​This program is free software; you can redistribute it and/or modify
9​it under the terms of the GNU General Public License as published by
10​the Free Software Foundation; either version 2 of the License, or
11​(at your option) any later version.
12​
13​This program is distributed in the hope that it will be useful,
14​but WITHOUT ANY WARRANTY; without even the implied warranty of
15​MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16​GNU General Public License for more details.
17​
18​You should have received a copy of the GNU General Public License
19​along with this program. If not, see <http://www.gnu.org/licenses/>.
20​*********************************************************************/
21​
22​#include "edid.h"
23​
24​namespace KWin
25​{
26​
27​static bool verifyHeader(const uint8_t *data)
28​{
29​ if (data[0] != 0x0 || data[7] != 0x0) {
30​ return false;
31​ }
32​
33​ return std::all_of(data + 1, data + 7,
34​ [](uint8_t byte) { return byte == 0xff; });
35​}
36​
37​static QSize parsePhysicalSize(const uint8_t *data)
38​{
39​ // Convert physical size from centimeters to millimeters.
40​ return QSize(data[0x15], data[0x16]) * 10;
41​}
42​
43​static QByteArray parseEisaId(const uint8_t *data)
44​{
45​ for (int i = 72; i <= 108; i += 18) {
46​ // Skip the block if it isn't used as monitor descriptor.
47​ if (data[i]) {
48​ continue;
49​ }
50​ if (data[i + 1]) {
51​ continue;
52​ }
53​
54​ // We have found the EISA ID, it's stored as ASCII.
55​ if (data[i + 3] == 0xfe) {
56​ return QByteArray(reinterpret_cast<const char *>(&data[i + 5]), 12).trimmed();
57​ }
58​ }
59​
60​ // If there isn't an ASCII EISA ID descriptor, try to decode PNP ID from
61​ // three 5 bit words packed into 2 bytes:
62​ //
63​ // | Byte | Bit |
64​ // | | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
65​ // ----------------------------------------
66​ // | 1 | 0)| (4| 3 | 2 | 1 | 0)| (4| 3 |
67​ // | | * | Character 1 | Char 2|
68​ // ----------------------------------------
69​ // | 2 | 2 | 1 | 0)| (4| 3 | 2 | 1 | 0)|
70​ // | | Character2| Character 3 |
71​ // ----------------------------------------
72​ const uint offset = 0x8;
73​
74​ char pnpId[4];
75​ pnpId[0] = 'A' + ((data[offset + 0] >> 2) & 0x1f) - 1;
76​ pnpId[1] = 'A' + (((data[offset + 0] & 0x3) << 3) | ((data[offset + 1] >> 5) & 0x7)) - 1;
77​ pnpId[2] = 'A' + (data[offset + 1] & 0x1f) - 1;
78​ pnpId[3] = '\0';
79​
80​ return QByteArray(pnpId);
81​}
82​
83​static QByteArray parseMonitorName(const uint8_t *data)
84​{
85​ for (int i = 72; i <= 108; i += 18) {
86​ // Skip the block if it isn't used as monitor descriptor.
87​ if (data[i]) {
88​ continue;
89​ }
90​ if (data[i + 1]) {
91​ continue;
92​ }
93​
94​ // We have found the monitor name, it's stored as ASCII.
95​ if (data[i + 3] == 0xfc) {
96​ return QByteArray(reinterpret_cast<const char *>(&data[i + 5]), 12).trimmed();
97​ }
98​ }
99​
100​ return QByteArray();
101​}
102​
103​static QByteArray parseSerialNumber(const uint8_t *data)
104​{
105​ for (int i = 72; i <= 108; i += 18) {
106​ // Skip the block if it isn't used as monitor descriptor.
107​ if (data[i]) {
108​ continue;
109​ }
110​ if (data[i + 1]) {
111​ continue;
112​ }
113​
114​ // We have found the serial number, it's stored as ASCII.
115​ if (data[i + 3] == 0xff) {
116​ return QByteArray(reinterpret_cast<const char *>(&data[i + 5]), 12).trimmed();
117​ }
118​ }
119​
120​ // Maybe there isn't an ASCII serial number descriptor, so use this instead.
121​ const uint32_t offset = 0xc;
122​
123​ uint32_t serialNumber = data[offset + 0];
124​ serialNumber |= uint32_t(data[offset + 1]) << 8;
125​ serialNumber |= uint32_t(data[offset + 2]) << 16;
126​ serialNumber |= uint32_t(data[offset + 3]) << 24;
127​ if (serialNumber) {
128​ return QByteArray::number(serialNumber);
129​ }
130​
131​ return QByteArray();
132​}
133​
134​Edid::Edid()
135​{
136​}
137​
138​Edid::Edid(const void *data, uint32_t size)
139​{
140​ const uint8_t *bytes = static_cast<const uint8_t *>(data);
141​
142​ if (size < 128) {
143​ return;
144​ }
145​
146​ if (!verifyHeader(bytes)) {
147​ return;
148​ }
149​
150​ m_physicalSize = parsePhysicalSize(bytes);
151​ m_eisaId = parseEisaId(bytes);
152​ m_monitorName = parseMonitorName(bytes);
153​ m_serialNumber = parseSerialNumber(bytes);
154​
155​ m_isValid = true;
156​}
157​
158​bool Edid::isValid() const
159​{
160​ return m_isValid;
161​}
162​
163​QSize Edid::physicalSize() const
164​{
165​ return m_physicalSize;
166​}
167​
168​QByteArray Edid::eisaId() const
169​{
170​ return m_eisaId;
171​}
172​
173​QByteArray Edid::monitorName() const
174​{
175​ return m_monitorName;
176​}
177​
178​QByteArray Edid::serialNumber() const
179​{
180​ return m_serialNumber;
181​}
182​
183​} // namespace KWin