CAN: Introduce CAN FD flag Error State Indicator (ESI)

Added hasErrorStateIndicator and setErrorStateIndicator to QCanBusFrame.

* Setting QCanBusFrame::setErrorStateIndicator(true)
  also sets QCanBusFrame::setFlexibleDataRateFormat(true)

* Setting QCanBusFrame::setFlexibleDataRateFormat(false)
  also sets QCanBusFrame::setErrorStateIndicator(false)

[ChangeLog][QCanBusFrame] Added error state indicator flag
to QCanBusFrame and set it appropriate receiving CAN FD
frames with the SocketCAN plugin. Setting this flag for
testing purposes is also possible.

Change-Id: I406b693fc7b7cde8a0d6b2c34c1f313800f11203
Reviewed-by: Rolf Eike Beer <eb@emlix.com>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

5 files changed, 100 insertions, 6 deletions

diff --git a/examples/serialbus/can/mainwindow.cpp b/examples/serialbus/can/mainwindow.cpp
index b27baaa..86938f3 100644
--- a/examples/serialbus/can/mainwindow.cpp
+++ b/examples/serialbus/can/mainwindow.cpp
@@ -184,6 +184,17 @@ void MainWindow::closeEvent(QCloseEvent *event)
     event->accept();
 }
 
+static QString frameFlags(const QCanBusFrame &frame)
+{
+    if (frame.hasBitrateSwitch() && frame.hasErrorStateIndicator())
+        return QStringLiteral(" B E ");
+    if (frame.hasBitrateSwitch())
+        return QStringLiteral(" B - ");
+    if (frame.hasErrorStateIndicator())
+        return QStringLiteral(" - E ");
+    return QStringLiteral(" - - ");
+}
+
 void MainWindow::checkMessages()
 {
     if (!m_canDevice)
@@ -202,8 +213,7 @@ void MainWindow::checkMessages()
                 .arg(frame.timeStamp().seconds(), 10, 10, QLatin1Char(' '))
                 .arg(frame.timeStamp().microSeconds() / 100, 4, 10, QLatin1Char('0'));
 
-        const QString flags = frame.hasBitrateSwitch()
-                ? QStringLiteral(" B - ") :  QStringLiteral(" - - ");
+        const QString flags = frameFlags(frame);
 
         m_ui->receivedMessagesEdit->append(time + flags + view);
     }
diff --git a/src/plugins/canbus/socketcan/socketcanbackend.cpp b/src/plugins/canbus/socketcan/socketcanbackend.cpp
index 53836b0..a41c8d1 100644
--- a/src/plugins/canbus/socketcan/socketcanbackend.cpp
+++ b/src/plugins/canbus/socketcan/socketcanbackend.cpp
@@ -450,6 +450,7 @@ bool SocketCanBackend::writeFrame(const QCanBusFrame &newData)
         frame.len = newData.payload().size();
         frame.can_id = canId;
         frame.flags = newData.hasBitrateSwitch() ? CANFD_BRS : 0;
+        frame.flags |= newData.hasErrorStateIndicator() ? CANFD_ESI : 0;
         ::memcpy(frame.data, newData.payload().constData(), frame.len);
 
         bytesWritten = ::write(canSocket, &frame, sizeof(frame));
@@ -679,6 +680,8 @@ void SocketCanBackend::readSocket()
             bufferedFrame.setFrameType(QCanBusFrame::ErrorFrame);
         if (frame.flags & CANFD_BRS)
             bufferedFrame.setBitrateSwitch(true);
+        if (frame.flags & CANFD_ESI)
+            bufferedFrame.setErrorStateIndicator(true);
 
         bufferedFrame.setFrameId(frame.can_id & CAN_EFF_MASK);
 
diff --git a/src/serialbus/qcanbusframe.cpp b/src/serialbus/qcanbusframe.cpp
index 26e1964..4f00c88 100644
--- a/src/serialbus/qcanbusframe.cpp
+++ b/src/serialbus/qcanbusframe.cpp
@@ -288,6 +288,30 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \fn QCanBusFrame::hasErrorStateIndicator() const
+    \since 5.9
+
+    Returns \c true if the CAN uses \e {Flexible Data-Rate} with \e {Error State Indicator} set.
+
+    This flag is set by the transmitter's CAN FD hardware to indicate the transmitter's error state.
+
+    \sa setErrorStateIndicator()
+*/
+
+/*!
+    \fn void QCanBusFrame::setErrorStateIndicator(bool errorStateIndicator)
+    \since 5.9
+
+    Set the \e {Flexible Data-Rate} flag \e {Error State Indicator} flag to \a errorStateIndicator.
+
+    When sending CAN FD frames, this flag is automatically set by the CAN FD hardware.
+    \c QCanBusFrame::setErrorStateIndicator() should only be used for application testing,
+    e.g. on virtual CAN FD busses.
+
+    \sa hasErrorStateIndicator()
+*/
+
+/*!
     \class QCanBusFrame::TimeStamp
     \inmodule QtSerialBus
     \since 5.8
@@ -397,7 +421,7 @@ QDataStream &operator<<(QDataStream &out, const QCanBusFrame &frame)
     out << stamp.seconds();
     out << stamp.microSeconds();
     if (frame.version >= QCanBusFrame::Version::Qt_5_9)
-        out << frame.hasBitrateSwitch();
+        out << frame.hasBitrateSwitch() << frame.hasErrorStateIndicator();
     return out;
 }
 
@@ -414,6 +438,7 @@ QDataStream &operator>>(QDataStream &in, QCanBusFrame &frame)
     bool extendedFrameFormat;
     bool flexibleDataRate;
     bool bitrateSwitch = false;
+    bool errorStateIndicator = false;
     QByteArray payload;
     qint64 seconds;
     qint64 microSeconds;
@@ -422,7 +447,7 @@ QDataStream &operator>>(QDataStream &in, QCanBusFrame &frame)
        >> payload >> seconds >> microSeconds;
 
     if (version >= QCanBusFrame::Version::Qt_5_9)
-        in >> bitrateSwitch;
+        in >> bitrateSwitch >> errorStateIndicator;
 
     frame.setFrameId(frameId);
     frame.version = version;
@@ -431,6 +456,7 @@ QDataStream &operator>>(QDataStream &in, QCanBusFrame &frame)
     frame.setExtendedFrameFormat(extendedFrameFormat);
     frame.setFlexibleDataRateFormat(flexibleDataRate);
     frame.setBitrateSwitch(bitrateSwitch);
+    frame.setErrorStateIndicator(errorStateIndicator);
     frame.setPayload(payload);
 
     frame.setTimeStamp(QCanBusFrame::TimeStamp(seconds, microSeconds));
diff --git a/src/serialbus/qcanbusframe.h b/src/serialbus/qcanbusframe.h
index 2c32cd8..7cab3e9 100644
--- a/src/serialbus/qcanbusframe.h
+++ b/src/serialbus/qcanbusframe.h
@@ -77,6 +77,7 @@ public:
         version(Qt_5_9),
         isFlexibleDataRate(0x0),
         isBitrateSwitch(0x0),
+        isErrorStateIndicator(0x0),
         reserved0(0x0)
     {
         Q_UNUSED(reserved0);
@@ -109,6 +110,7 @@ public:
         version(Qt_5_9),
         isFlexibleDataRate(data.length() > 8 ? 0x1 : 0x0),
         isBitrateSwitch(0x0),
+        isErrorStateIndicator(0x0),
         reserved0(0x0),
         load(data)
     {
@@ -226,8 +228,10 @@ public:
     void setFlexibleDataRateFormat(bool isFlexibleData) Q_DECL_NOTHROW
     {
         isFlexibleDataRate = (isFlexibleData & 0x1);
-        if (!isFlexibleData)
+        if (!isFlexibleData) {
             isBitrateSwitch = 0x0;
+            isErrorStateIndicator = 0x0;
+        }
     }
 
     bool hasBitrateSwitch() const Q_DECL_NOTHROW { return (isBitrateSwitch & 0x1); }
@@ -238,6 +242,14 @@ public:
             isFlexibleDataRate = 0x1;
     }
 
+    bool hasErrorStateIndicator() const Q_DECL_NOTHROW { return (isErrorStateIndicator & 0x1); }
+    void setErrorStateIndicator(bool errorStateIndicator) Q_DECL_NOTHROW
+    {
+        isErrorStateIndicator = (errorStateIndicator & 0x1);
+        if (errorStateIndicator)
+            isFlexibleDataRate = 0x1;
+    }
+
 #ifndef QT_NO_DATASTREAM
     friend Q_SERIALBUS_EXPORT QDataStream &operator<<(QDataStream &, const QCanBusFrame &);
     friend Q_SERIALBUS_EXPORT QDataStream &operator>>(QDataStream &, QCanBusFrame &);
@@ -258,7 +270,8 @@ private:
     quint8 isFlexibleDataRate:1;
 
     quint8 isBitrateSwitch:1;
-    quint8 reserved0:7;
+    quint8 isErrorStateIndicator:1;
+    quint8 reserved0:6;
 
     // reserved for future use
     quint8 reserved[2];
diff --git a/tests/auto/qcanbusframe/tst_qcanbusframe.cpp b/tests/auto/qcanbusframe/tst_qcanbusframe.cpp
index 4decffa..7907017 100644
--- a/tests/auto/qcanbusframe/tst_qcanbusframe.cpp
+++ b/tests/auto/qcanbusframe/tst_qcanbusframe.cpp
@@ -49,6 +49,7 @@ private slots:
     void payload();
     void timeStamp();
     void bitRateSwitch();
+    void errorStateIndicator();
 
     void tst_isValid_data();
     void tst_isValid();
@@ -222,6 +223,47 @@ void tst_QCanBusFrame::bitRateSwitch()
      QVERIFY(!frame2.hasBitrateSwitch());
 }
 
+void tst_QCanBusFrame::errorStateIndicator()
+{
+    QCanBusFrame frame(QCanBusFrame::DataFrame);
+    QVERIFY(!frame.hasErrorStateIndicator());
+
+    // set CAN FD does not set ESI
+    frame.setFlexibleDataRateFormat(true);
+    QVERIFY(frame.hasFlexibleDataRateFormat());
+    QVERIFY(!frame.hasErrorStateIndicator());
+
+    // set ESI keeps CAN FD
+    frame.setErrorStateIndicator(true);
+    QVERIFY(frame.hasFlexibleDataRateFormat());
+    QVERIFY(frame.hasErrorStateIndicator());
+
+    // clear ESI keeps CAN FD
+    frame.setErrorStateIndicator(false);
+    QVERIFY(frame.hasFlexibleDataRateFormat());
+    QVERIFY(!frame.hasErrorStateIndicator());
+
+    // clear CAN FD
+    frame.setFlexibleDataRateFormat(false);
+    QVERIFY(!frame.hasFlexibleDataRateFormat());
+    QVERIFY(!frame.hasErrorStateIndicator());
+
+    // set ESI sets CAN FD
+    frame.setErrorStateIndicator(true);
+    QVERIFY(frame.hasFlexibleDataRateFormat());
+    QVERIFY(frame.hasErrorStateIndicator());
+
+    // clear CAN FD clears ESI
+    frame.setFlexibleDataRateFormat(false);
+    QVERIFY(!frame.hasFlexibleDataRateFormat());
+    QVERIFY(!frame.hasErrorStateIndicator());
+
+    // default constructed CAN FD frame has no ESI
+    const QCanBusFrame frame2(0x123, QByteArray(10, 0x55));
+    QVERIFY(frame2.hasFlexibleDataRateFormat());
+    QVERIFY(!frame2.hasErrorStateIndicator());
+}
+
 void tst_QCanBusFrame::tst_isValid_data()
 {
     QTest::addColumn<QCanBusFrame::FrameType>("frameType");