eglfs_kms: Output cloning support

{
    "device": "/dev/dri/card0",
    "outputs": [
	{ "name": "HDMI1", "mode": "1920x1080" },
	{ "name": "DP1", "mode": "1920x1080", "clones": "HDMI1" }
   ]
}

Here, assuming the QScreen for DP1 is unused and the resolution is the same,
DP1 will simply mirror whatever is on HDMI1.

The plane-based mouse cursor is not currently supported. Same goes for any
form of scaling since this simply scans out the same framebuffer on all
target CRTCs.

Task-number: QTBUG-62262
Change-Id: I391be204264284a1bff752ebc2a1dbe5c8592013
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 16 insertions, 2 deletions

diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
index 3680afa7ec..f6ee68d1c4 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
@@ -62,25 +62,39 @@ public:
     gbm_surface *createSurface();
     void resetSurface();
 
+    void initCloning(QPlatformScreen *screenThisScreenClones,
+                     const QVector<QPlatformScreen *> &screensCloningThisScreen);
+
     void waitForFlip() override;
     void flip() override;
     void flipFinished() override;
 
 private:
+    void ensureModeSet(uint32_t fb);
+    void cloneDestFlipFinished(QEglFSKmsGbmScreen *cloneDestScreen);
+    void updateFlipStatus();
+
     gbm_surface *m_gbm_surface;
 
     gbm_bo *m_gbm_bo_current;
     gbm_bo *m_gbm_bo_next;
+    bool m_flipPending;
 
     QScopedPointer<QEglFSKmsGbmCursor> m_cursor;
 
     struct FrameBuffer {
-        FrameBuffer() : fb(0) {}
-        uint32_t fb;
+        uint32_t fb = 0;
     };
     static void bufferDestroyedHandler(gbm_bo *bo, void *data);
     FrameBuffer *framebufferForBufferObject(gbm_bo *bo);
 
+    QEglFSKmsGbmScreen *m_cloneSource;
+    struct CloneDestination {
+        QEglFSKmsGbmScreen *screen = nullptr;
+        bool cloneFlipPending = false;
+    };
+    QVector<CloneDestination> m_cloneDests;
+
     static QMutex m_waitForFlipMutex;
 };