Adapt, improve and verify documentation

Fixes: QTBUG-91211
Change-Id: I38dc720402f0b1a9806ce39c31dbbd52f7d66aa6
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

6 files changed, 106 insertions, 14 deletions

diff --git a/src/serialbus/doc/src/passthrucan.qdoc b/src/serialbus/doc/src/passthrucan.qdoc
index eff2ef7..2515b67 100644
--- a/src/serialbus/doc/src/passthrucan.qdoc
+++ b/src/serialbus/doc/src/passthrucan.qdoc
@@ -31,7 +31,7 @@
     \brief Overview of how to use the J2534 Pass-Thru CAN plugin.
 
     The Pass-Thru CAN plugin accesses CAN adapters via the SAE J2534 Pass-Thru API.
-    SAE J2534 is a standard for accessing vehicle busses from an x86 Windows PC.
+    SAE J2534 is a standard for accessing vehicle buses from an x86 Windows PC.
     Although the API is specified only for 32-bit Windows, some vendors also provide
     implementations for 64-bit Windows and other operating systems such as Linux.
 
diff --git a/src/serialbus/doc/src/qt6-changes.qdoc b/src/serialbus/doc/src/qt6-changes.qdoc
new file mode 100644
index 0000000..f089f66
--- /dev/null
+++ b/src/serialbus/doc/src/qt6-changes.qdoc
@@ -0,0 +1,50 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+/*!
+    \page qtserialport-changes-qt6.html
+
+    \title Changes to Qt SerialBus
+    \ingroup changes-qt-5-to-6
+    \brief Migrate Qt SerialBus to Qt 6.
+
+    Qt 6 is a result of the conscious effort to make the framework more
+    efficient and easy to use.
+    We try to maintain binary and source compatibility for all the public
+    APIs in each release. But some changes were inevitable in an effort to
+    make Qt a better framework.
+    In this topic, we summarize those changes in Qt SerialBus module and
+    provide guidance to handle them.
+
+    \section1 Changes overview
+    The Qt SerialBus module is generally speaking source compatible with the
+    Qt5 version and users of the library should be able to continue with no or
+    minor changes to their project.
+
+    \section1 Build system
+    As with Qt 6 in general, the Qt SerialBus module has CMake support in
+    addition to qmake.
+*/
diff --git a/src/serialbus/doc/src/qtmodbus-backends.qdoc b/src/serialbus/doc/src/qtmodbus-backends.qdoc
index 4b3b3d5..ad5cc9e 100644
--- a/src/serialbus/doc/src/qtmodbus-backends.qdoc
+++ b/src/serialbus/doc/src/qtmodbus-backends.qdoc
@@ -30,10 +30,9 @@
 
     \brief Implemented Qt Modbus.
 
-    Modbus is a request/reply protocol that has one Modbus client in its network and may have many
-    Modbus servers. Servers can control only their own internal states and clients can read and write
-    data in them. Modbus is not restricted by the network type, in theory it can use any
-    QIODevice. However, not every plugin supports all classes derived from QIODevice.
+    Modbus is a request/reply protocol that has one Modbus client in its
+    network and may have many Modbus servers. Servers can control only
+    their own internal states, and clients can read and write data in them.
 
     Each Modbus server has four tables in which it can store data.
 
diff --git a/src/serialbus/doc/src/qtserialbus-index.qdoc b/src/serialbus/doc/src/qtserialbus-index.qdoc
index ca2c54d..85b0c00 100644
--- a/src/serialbus/doc/src/qtserialbus-index.qdoc
+++ b/src/serialbus/doc/src/qtserialbus-index.qdoc
@@ -43,11 +43,13 @@
     #include <QtSerialBus>
     \endcode
 
-    To link against the module, add this line to your qmake .pro file:
+    To use the module with CMake, use the \c{find_package()} command to locate
+    the needed module components in the \c{Qt6} package:
+    \include qtserialbus-module-use.qdocinc cmakebuild
 
-    \code
-    QT += serialbus
-    \endcode
+    To use the module for building with qmake, add the module as a value of the
+    \c QT variable in the project's .pro file:
+    \include qtserialbus-module-use.qdocinc qmakebuild
 
     \section1 Supported Buses and Protocols
 
@@ -106,5 +108,6 @@
          \li \l {CAN Bus Example}
          \li \l {Modbus Client example}
          \li \l {Modbus Server example}
+         \li \l {Modbus Custom command example}
     \endlist
 */
diff --git a/src/serialbus/doc/src/qtserialbus-module-cpp.qdoc b/src/serialbus/doc/src/qtserialbus-module-cpp.qdoc
index 57c81ea..cf591cf 100644
--- a/src/serialbus/doc/src/qtserialbus-module-cpp.qdoc
+++ b/src/serialbus/doc/src/qtserialbus-module-cpp.qdoc
@@ -44,12 +44,13 @@
     #include <QCanBusDevice>
     \endcode
 
-    The .pro file should have the \e serialbus keyword added
-
-    \code
-    QT += serialbus
-    \endcode
+    To use the module with CMake, use the \c{find_package()} command to locate
+    the needed module components in the \c{Qt6} package:
+    \include qtserialbus-module-use.qdocinc cmakebuild
 
+    To use the module for building with qmake, add the module as a value of the
+    \c QT variable in the project's .pro file:
+    \include qtserialbus-module-use.qdocinc qmakebuild
 
     See more in the \l {Qt Serial Bus} {Qt Serial Bus Overview}.
 */
diff --git a/src/serialbus/doc/src/qtserialbus-module-use.qdocinc b/src/serialbus/doc/src/qtserialbus-module-use.qdocinc
new file mode 100644
index 0000000..d69b65e
--- /dev/null
+++ b/src/serialbus/doc/src/qtserialbus-module-use.qdocinc
@@ -0,0 +1,39 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [cmakebuild]
+    \code
+    find_package(Qt6 COMPONENTS SerialBus REQUIRED)
+    target_link_libraries(mytarget PRIVATE Qt6::SerialBus)
+    \endcode
+//! [cmakebuild]
+
+//! [qmakebuild]
+    \code
+    QT += serialbus
+    \endcode
+//! [qmakebuild]