platforms/drm: Add support for setting overscan

BUG: 428201

src/abstract_wayland_output.cpp

@@ -37,7 +37,10 @@ AbstractWaylandOutput::Capabilities AbstractWaylandOutput::capabilities() const
 
 void AbstractWaylandOutput::setCapabilityInternal(Capability capability, bool on)
 {
-    m_capabilities.setFlag(capability, on);
+    if (static_cast<bool>(m_capabilities & capability) != on) {
+        m_capabilities.setFlag(capability, on);
+        emit capabilitiesChanged();
+    }
 }
 
 QString AbstractWaylandOutput::name() const
@@ -172,6 +175,10 @@ void AbstractWaylandOutput::applyChanges(const KWaylandServer::OutputChangeSet *
         setScale(changeSet->scaleF());
         emitModeChanged = true;
     }
+    if (changeSet->overscanChanged()) {
+        qCDebug(KWIN_CORE) << "Setting overscan:" << changeSet->overscan();
+        setOverscan(changeSet->overscan());
+    }
 
     overallSizeCheckNeeded |= emitModeChanged;
     if (overallSizeCheckNeeded) {
@@ -343,4 +350,22 @@ bool AbstractWaylandOutput::isBeingRecorded()
     return m_recorders;
 }
 
+void AbstractWaylandOutput::setOverscanInternal(uint32_t overscan)
+{
+    if (m_overscan != overscan) {
+        m_overscan = overscan;
+        emit overscanChanged();
+    }
+}
+
+uint32_t AbstractWaylandOutput::overscan() const
+{
+    return m_overscan;
+}
+
+void AbstractWaylandOutput::setOverscan(uint32_t overscan)
+{
+    Q_UNUSED(overscan);
+}
+
 }

src/abstract_wayland_output.h

@@ -65,6 +65,7 @@ public:
 
     enum class Capability : uint {
         Dpms = 0x1,
+        Overscan = 0x2,
     };
     Q_DECLARE_FLAGS(Capabilities, Capability)
 
@@ -128,6 +129,9 @@ public:
     DpmsMode dpmsMode() const;
     virtual void setDpmsMode(DpmsMode mode);
 
+    uint32_t overscan() const;
+    virtual void setOverscan(uint32_t overscan);
+
     /**
      * Returns a matrix that can translate into the display's coordinates system
      */
@@ -144,6 +148,8 @@ Q_SIGNALS:
     void scaleChanged();
     void transformChanged();
     void dpmsModeChanged();
+    void capabilitiesChanged();
+    void overscanChanged();
 
 protected:
     void initialize(const QString &model, const QString &manufacturer,
@@ -178,6 +184,7 @@ protected:
     void setDpmsModeInternal(DpmsMode dpmsMode);
     void setCapabilityInternal(Capability capability, bool on = true);
     void setSubPixelInternal(SubPixel subPixel);
+    void setOverscanInternal(uint32_t overscan);
 
     QSize orientateSize(const QSize &size) const;
 
@@ -202,6 +209,7 @@ private:
     int m_recorders = 0;
     bool m_isEnabled = true;
     bool m_internal = false;
+    uint32_t m_overscan = 0;
 };
 
 }

src/plugins/platforms/drm/drm_object_connector.cpp

@@ -62,6 +62,7 @@ bool DrmConnector::init()
             PropertyDefinition(QByteArrayLiteral("non-desktop")),
             PropertyDefinition(QByteArrayLiteral("DPMS")),
             PropertyDefinition(QByteArrayLiteral("EDID")),
+            PropertyDefinition(QByteArrayLiteral("overscan")),
         }, DRM_MODE_OBJECT_CONNECTOR)) {
         return false;
     }
@@ -206,6 +207,22 @@ AbstractWaylandOutput::SubPixel DrmConnector::subpixel() const
     }
 }
 
+bool DrmConnector::hasOverscan() const
+{
+    return m_props[static_cast<uint32_t>(PropertyIndex::Overscan)];
+}
 
+uint32_t DrmConnector::overscan() const
+{
+    if (const auto &prop = m_props[static_cast<uint32_t>(PropertyIndex::Overscan)]) {
+        return prop->value();
+    }
+    return 0;
+}
+
+void DrmConnector::setOverscan(uint32_t overscan)
+{
+    setValue(PropertyIndex::Overscan, overscan);
+}
 
 }

src/plugins/platforms/drm/drm_object_connector.h

@@ -35,6 +35,7 @@ public:
         NonDesktop = 1,
         Dpms = 2,
         Edid = 3,
+        Overscan = 4,
         Count
     };
 
@@ -82,6 +83,10 @@ public:
 
     AbstractWaylandOutput::SubPixel subpixel() const;
 
+    bool hasOverscan() const;
+    uint32_t overscan() const;
+    void setOverscan(uint32_t overscan);
+
 private:
     DrmScopedPointer<drmModeConnector> m_conn;
     QVector<uint32_t> m_encoders;

src/plugins/platforms/drm/drm_output.cpp

@@ -158,6 +158,10 @@ bool DrmOutput::init()
     setSubPixelInternal(m_conn->subpixel());
     setInternal(m_conn->isInternal());
     setCapabilityInternal(Capability::Dpms);
+    if (m_conn->hasOverscan()) {
+        setCapabilityInternal(Capability::Overscan);
+        setOverscanInternal(m_conn->overscan());
+    }
     initOutputDevice();
 
     m_pipeline = new DrmPipeline(this, m_gpu, m_conn, m_crtc, m_primaryPlane, m_cursorPlane);
@@ -417,4 +421,12 @@ bool DrmOutput::setGammaRamp(const GammaRamp &gamma)
     return m_pipeline->setGammaRamp(gamma);
 }
 
+void DrmOutput::setOverscan(uint32_t overscan)
+{
+    if (m_conn->hasOverscan() && overscan <= 100) {
+        m_conn->setOverscan(overscan);
+        setOverscanInternal(overscan);
+    }
+}
+
 }

src/plugins/platforms/drm/drm_output.h

@@ -102,6 +102,7 @@ private:
 
     int gammaRampSize() const override;
     bool setGammaRamp(const GammaRamp &gamma) override;
+    void setOverscan(uint32_t overscan) override;
 
     DrmBackend *m_backend;
     DrmGpu *m_gpu;

src/waylandoutputdevice.cpp

@@ -20,6 +20,15 @@ static KWaylandServer::OutputDeviceInterface::SubPixel kwinSubPixelToOutputDevic
     return static_cast<KWaylandServer::OutputDeviceInterface::SubPixel>(subPixel);
 }
 
+static KWaylandServer::OutputDeviceInterface::Capabilities kwinCapabilitiesToOutputDeviceCapabilities(AbstractWaylandOutput::Capabilities caps)
+{
+    KWaylandServer::OutputDeviceInterface::Capabilities ret;
+    if (caps & AbstractWaylandOutput::Capability::Overscan) {
+        ret |= KWaylandServer::OutputDeviceInterface::Capability::Overscan;
+    }
+    return ret;
+}
+
 WaylandOutputDevice::WaylandOutputDevice(AbstractWaylandOutput *output, QObject *parent)
     : QObject(parent)
     , m_platformOutput(output)
@@ -36,6 +45,8 @@ WaylandOutputDevice::WaylandOutputDevice(AbstractWaylandOutput *output, QObject
     m_outputDevice->setEisaId(output->eisaId());
     m_outputDevice->setSerialNumber(output->serialNumber());
     m_outputDevice->setSubPixel(kwinSubPixelToOutputDeviceSubPixel(output->subPixel()));
+    m_outputDevice->setOverscan(output->overscan());
+    m_outputDevice->setCapabilities(kwinCapabilitiesToOutputDeviceCapabilities(output->capabilities()));
 
     const auto modes = output->modes();
     for (const AbstractWaylandOutput::Mode &mode : modes) {
@@ -64,6 +75,10 @@ WaylandOutputDevice::WaylandOutputDevice(AbstractWaylandOutput *output, QObject
             this, &WaylandOutputDevice::handleTransformChanged);
     connect(output, &AbstractWaylandOutput::modeChanged,
             this, &WaylandOutputDevice::handleModeChanged);
+    connect(output, &AbstractWaylandOutput::capabilitiesChanged,
+            this, &WaylandOutputDevice::handleCapabilitiesChanged);
+    connect(output, &AbstractWaylandOutput::overscanChanged,
+            this, &WaylandOutputDevice::handleOverscanChanged);
 }
 
 void WaylandOutputDevice::handleGeometryChanged()
@@ -95,4 +110,14 @@ void WaylandOutputDevice::handleModeChanged()
     m_outputDevice->setCurrentMode(m_platformOutput->modeSize(), m_platformOutput->refreshRate());
 }
 
+void WaylandOutputDevice::handleCapabilitiesChanged()
+{
+    m_outputDevice->setCapabilities(kwinCapabilitiesToOutputDeviceCapabilities(m_platformOutput->capabilities()));
+}
+
+void WaylandOutputDevice::handleOverscanChanged()
+{
+    m_outputDevice->setOverscan(m_platformOutput->overscan());
+}
+
 } // namespace KWin

src/waylandoutputdevice.h

@@ -26,6 +26,8 @@ private Q_SLOTS:
     void handleEnabledChanged();
     void handleTransformChanged();
     void handleModeChanged();
+    void handleCapabilitiesChanged();
+    void handleOverscanChanged();
 
 private:
     AbstractWaylandOutput *m_platformOutput;