6 files changed, 505 insertions, 9 deletions

diff --git a/src/plugins/platforms/linuxfb/linuxfb.pro b/src/plugins/platforms/linuxfb/linuxfb.pro
index e2fa31211d..d3a4476f80 100644
--- a/src/plugins/platforms/linuxfb/linuxfb.pro
+++ b/src/plugins/platforms/linuxfb/linuxfb.pro
@@ -10,8 +10,18 @@ QT += \
 qtHaveModule(input_support-private): \
     QT += input_support-private
 
-SOURCES = main.cpp qlinuxfbintegration.cpp qlinuxfbscreen.cpp
-HEADERS = qlinuxfbintegration.h qlinuxfbscreen.h
+SOURCES = main.cpp \
+          qlinuxfbintegration.cpp \
+          qlinuxfbscreen.cpp
+
+HEADERS = qlinuxfbintegration.h \
+          qlinuxfbscreen.h
+
+qtHaveModule(kms_support-private) {
+    QT += kms_support-private
+    SOURCES += qlinuxfbdrmscreen.cpp
+    HEADERS += qlinuxfbdrmscreen.h
+}
 
 OTHER_FILES += linuxfb.json
 
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp b/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp
new file mode 100644
index 0000000000..bdf2634642
--- /dev/null
+++ b/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp
@@ -0,0 +1,409 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// Experimental DRM dumb buffer backend.
+//
+// TODO:
+// Multiscreen: QWindow-QScreen(-output) association. Needs some reorg (device cannot be owned by screen)
+// Find card via devicediscovery like in eglfs_kms.
+// Mode restore like QEglFSKmsInterruptHandler.
+// Formats other then 32 bpp?
+// grabWindow
+
+#include "qlinuxfbdrmscreen.h"
+#include <QLoggingCategory>
+#include <QGuiApplication>
+#include <QPainter>
+#include <QtFbSupport/private/qfbcursor_p.h>
+#include <QtFbSupport/private/qfbwindow_p.h>
+#include <QtKmsSupport/private/qkmsdevice_p.h>
+#include <QtCore/private/qcore_unix_p.h>
+#include <sys/mman.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(qLcFbDrm, "qt.qpa.fb")
+
+static const int BUFFER_COUNT = 2;
+
+class QLinuxFbDevice : public QKmsDevice
+{
+public:
+    struct Framebuffer {
+        Framebuffer() : handle(0), pitch(0), size(0), fb(0), p(MAP_FAILED) { }
+        uint32_t handle;
+        uint32_t pitch;
+        uint64_t size;
+        uint32_t fb;
+        void *p;
+        QImage wrapper;
+    };
+
+    struct Output {
+        Output() : backFb(0), flipped(false) { }
+        QKmsOutput kmsOutput;
+        Framebuffer fb[BUFFER_COUNT];
+        QRegion dirty[BUFFER_COUNT];
+        int backFb;
+        bool flipped;
+        QSize currentRes() const {
+            const drmModeModeInfo &modeInfo(kmsOutput.modes[kmsOutput.mode]);
+            return QSize(modeInfo.hdisplay, modeInfo.vdisplay);
+        }
+    };
+
+    QLinuxFbDevice(QKmsScreenConfig *screenConfig);
+
+    bool open() override;
+    void close() override;
+
+    void createFramebuffers();
+    void destroyFramebuffers();
+    void setMode();
+
+    void swapBuffers(Output *output);
+
+    int outputCount() const { return m_outputs.count(); }
+    Output *output(int idx) { return &m_outputs[idx]; }
+
+private:
+    void *nativeDisplay() const override;
+    QPlatformScreen *createScreen(const QKmsOutput &output) override;
+    void registerScreen(QPlatformScreen *screen,
+                        const QPoint &virtualPos,
+                        const QList<QPlatformScreen *> &virtualSiblings) override;
+
+    bool createFramebuffer(Output *output, int bufferIdx);
+    void destroyFramebuffer(Output *output, int bufferIdx);
+
+    static void pageFlipHandler(int fd, unsigned int sequence,
+                                unsigned int tv_sec, unsigned int tv_usec, void *user_data);
+
+    QVector<Output> m_outputs;
+};
+
+QLinuxFbDevice::QLinuxFbDevice(QKmsScreenConfig *screenConfig)
+    : QKmsDevice(screenConfig, QStringLiteral("/dev/dri/card0"))
+{
+}
+
+bool QLinuxFbDevice::open()
+{
+    int fd = qt_safe_open(devicePath().toLocal8Bit().constData(), O_RDWR | O_CLOEXEC);
+    if (fd == -1) {
+        qErrnoWarning("Could not open DRM device %s", qPrintable(devicePath()));
+        return false;
+    }
+
+    uint64_t hasDumbBuf = 0;
+    if (drmGetCap(fd, DRM_CAP_DUMB_BUFFER, &hasDumbBuf) == -1 || !hasDumbBuf) {
+        qWarning("Dumb buffers not supported");
+        qt_safe_close(fd);
+        return false;
+    }
+
+    setFd(fd);
+
+    qCDebug(qLcFbDrm, "DRM device %s opened", qPrintable(devicePath()));
+
+    return true;
+}
+
+void QLinuxFbDevice::close()
+{
+    for (Output &output : m_outputs)
+        output.kmsOutput.cleanup(this); // restore mode
+
+    m_outputs.clear();
+
+    if (fd() != -1) {
+        qCDebug(qLcFbDrm, "Closing DRM device");
+        qt_safe_close(fd());
+        setFd(-1);
+    }
+}
+
+void *QLinuxFbDevice::nativeDisplay() const
+{
+    Q_UNREACHABLE();
+    return nullptr;
+}
+
+QPlatformScreen *QLinuxFbDevice::createScreen(const QKmsOutput &output)
+{
+    qCDebug(qLcFbDrm, "Got a new output: %s", qPrintable(output.name));
+    Output o;
+    o.kmsOutput = output;
+    m_outputs.append(o);
+    return nullptr; // no platformscreen, we are not a platform plugin
+}
+
+void QLinuxFbDevice::registerScreen(QPlatformScreen *screen,
+                            const QPoint &virtualPos,
+                            const QList<QPlatformScreen *> &virtualSiblings)
+{
+    Q_UNUSED(screen);
+    Q_UNUSED(virtualPos);
+    Q_UNUSED(virtualSiblings);
+    Q_UNREACHABLE();
+}
+
+bool QLinuxFbDevice::createFramebuffer(QLinuxFbDevice::Output *output, int bufferIdx)
+{
+    const QSize size = output->currentRes();
+    const uint32_t w = size.width();
+    const uint32_t h = size.height();
+    drm_mode_create_dumb creq = {
+        h,
+        w,
+        32,
+        0, 0, 0, 0
+    };
+    if (drmIoctl(fd(), DRM_IOCTL_MODE_CREATE_DUMB, &creq) == -1) {
+        qErrnoWarning(errno, "Failed to create dumb buffer");
+        return false;
+    }
+
+    Framebuffer &fb(output->fb[bufferIdx]);
+    fb.handle = creq.handle;
+    fb.pitch = creq.pitch;
+    fb.size = creq.size;
+    qCDebug(qLcFbDrm, "Got a dumb buffer for size %dx%d, handle %u, pitch %u, size %u",
+            w, h, fb.handle, fb.pitch, (uint) fb.size);
+
+    if (drmModeAddFB(fd(), w, h, 24, 32, fb.pitch, fb.handle, &fb.fb) == -1) {
+        qErrnoWarning(errno, "Failed to add FB");
+        return false;
+    }
+
+    drm_mode_map_dumb mreq = {
+        fb.handle,
+        0, 0
+    };
+    if (drmIoctl(fd(), DRM_IOCTL_MODE_MAP_DUMB, &mreq) == -1) {
+        qErrnoWarning(errno, "Failed to map dumb buffer");
+        return false;
+    }
+    fb.p = mmap(0, fb.size, PROT_READ | PROT_WRITE, MAP_SHARED, fd(), mreq.offset);
+    if (fb.p == MAP_FAILED) {
+        qErrnoWarning(errno, "Failed to mmap dumb buffer");
+        return false;
+    }
+
+    qCDebug(qLcFbDrm, "FB is %u, mapped at %p", fb.fb, fb.p);
+    memset(fb.p, 0, fb.size);
+
+    fb.wrapper = QImage(static_cast<uchar *>(fb.p), w, h, fb.pitch, QImage::Format_ARGB32);
+
+    return true;
+}
+
+void QLinuxFbDevice::createFramebuffers()
+{
+    for (Output &output : m_outputs) {
+        for (int i = 0; i < BUFFER_COUNT; ++i) {
+            if (!createFramebuffer(&output, i))
+                return;
+        }
+        output.backFb = 0;
+        output.flipped = false;
+    }
+}
+
+void QLinuxFbDevice::destroyFramebuffer(QLinuxFbDevice::Output *output, int bufferIdx)
+{
+    Framebuffer &fb(output->fb[bufferIdx]);
+    if (fb.p != MAP_FAILED)
+        munmap(fb.p, fb.size);
+    if (fb.fb) {
+        if (drmModeRmFB(fd(), fb.fb) == -1)
+            qErrnoWarning("Failed to remove fb");
+    }
+    if (fb.handle) {
+        drm_mode_destroy_dumb dreq = { fb.handle };
+        if (drmIoctl(fd(), DRM_IOCTL_MODE_DESTROY_DUMB, &dreq) == -1)
+            qErrnoWarning(errno, "Failed to destroy dumb buffer %u", fb.handle);
+    }
+    fb = Framebuffer();
+}
+
+void QLinuxFbDevice::destroyFramebuffers()
+{
+    for (Output &output : m_outputs) {
+        for (int i = 0; i < BUFFER_COUNT; ++i)
+            destroyFramebuffer(&output, i);
+    }
+}
+
+void QLinuxFbDevice::setMode()
+{
+    for (Output &output : m_outputs) {
+        drmModeModeInfo &modeInfo(output.kmsOutput.modes[output.kmsOutput.mode]);
+        if (drmModeSetCrtc(fd(), output.kmsOutput.crtc_id, output.fb[0].fb, 0, 0,
+                           &output.kmsOutput.connector_id, 1, &modeInfo) == -1) {
+            qErrnoWarning(errno, "Failed to set mode");
+            return;
+        }
+
+        output.kmsOutput.mode_set = true; // have cleanup() to restore the mode
+        output.kmsOutput.setPowerState(this, QPlatformScreen::PowerStateOn);
+    }
+}
+
+void QLinuxFbDevice::pageFlipHandler(int fd, unsigned int sequence,
+                                     unsigned int tv_sec, unsigned int tv_usec,
+                                     void *user_data)
+{
+    Q_UNUSED(fd);
+    Q_UNUSED(sequence);
+    Q_UNUSED(tv_sec);
+    Q_UNUSED(tv_usec);
+
+    Output *output = static_cast<Output *>(user_data);
+    output->backFb = (output->backFb + 1) % BUFFER_COUNT;
+}
+
+void QLinuxFbDevice::swapBuffers(Output *output)
+{
+    Framebuffer &fb(output->fb[output->backFb]);
+    if (drmModePageFlip(fd(), output->kmsOutput.crtc_id, fb.fb, DRM_MODE_PAGE_FLIP_EVENT, output) == -1) {
+        qErrnoWarning(errno, "Page flip failed");
+        return;
+    }
+
+    const int fbIdx = output->backFb;
+    while (output->backFb == fbIdx) {
+        drmEventContext drmEvent = {
+            DRM_EVENT_CONTEXT_VERSION,
+            nullptr,
+            pageFlipHandler
+        };
+        // Blocks until there is something to read on the drm fd
+        // and calls back pageFlipHandler once the flip completes.
+        drmHandleEvent(fd(), &drmEvent);
+    }
+}
+
+QLinuxFbDrmScreen::QLinuxFbDrmScreen(const QStringList &args)
+    : m_screenConfig(nullptr),
+      m_device(nullptr)
+{
+    Q_UNUSED(args);
+}
+
+QLinuxFbDrmScreen::~QLinuxFbDrmScreen()
+{
+    if (m_device) {
+        m_device->destroyFramebuffers();
+        m_device->close();
+        delete m_device;
+    }
+    delete m_screenConfig;
+}
+
+bool QLinuxFbDrmScreen::initialize()
+{
+    m_screenConfig = new QKmsScreenConfig;
+    m_device = new QLinuxFbDevice(m_screenConfig);
+    if (!m_device->open())
+        return false;
+
+    // Discover outputs. Calls back Device::createScreen().
+    m_device->createScreens();
+    // Now off to dumb buffer specifics.
+    m_device->createFramebuffers();
+    // Do the modesetting.
+    m_device->setMode();
+
+    QLinuxFbDevice::Output *output(m_device->output(0));
+
+    mGeometry = QRect(QPoint(0, 0), output->currentRes());
+    mDepth = 32;
+    mFormat = QImage::Format_ARGB32;
+    mPhysicalSize = output->kmsOutput.physical_size;
+    qCDebug(qLcFbDrm) << mGeometry << mPhysicalSize;
+
+    QFbScreen::initializeCompositor();
+
+    mCursor = new QFbCursor(this);
+
+    return true;
+}
+
+QRegion QLinuxFbDrmScreen::doRedraw()
+{
+    const QRegion dirty = QFbScreen::doRedraw();
+    if (dirty.isEmpty())
+        return dirty;
+
+    QLinuxFbDevice::Output *output(m_device->output(0));
+
+    for (int i = 0; i < BUFFER_COUNT; ++i)
+        output->dirty[i] += dirty;
+
+    if (output->fb[output->backFb].wrapper.isNull())
+        return dirty;
+
+    QPainter pntr(&output->fb[output->backFb].wrapper);
+    // Image has alpha but no need for blending at this stage.
+    // Do not waste time with the default SourceOver.
+    pntr.setCompositionMode(QPainter::CompositionMode_Source);
+    for (const QRect &rect : qAsConst(output->dirty[output->backFb]))
+        pntr.drawImage(rect, mScreenImage, rect);
+    pntr.end();
+
+    output->dirty[output->backFb] = QRegion();
+
+    m_device->swapBuffers(output);
+
+    return dirty;
+}
+
+QPixmap QLinuxFbDrmScreen::grabWindow(WId wid, int x, int y, int width, int height) const
+{
+    Q_UNUSED(wid);
+    Q_UNUSED(x);
+    Q_UNUSED(y);
+    Q_UNUSED(width);
+    Q_UNUSED(height);
+
+    return QPixmap();
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.h b/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.h
new file mode 100644
index 0000000000..50a9576798
--- /dev/null
+++ b/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.h
@@ -0,0 +1,68 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QLINUXFBDRMSCREEN_H
+#define QLINUXFBDRMSCREEN_H
+
+#include <QtFbSupport/private/qfbscreen_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QKmsScreenConfig;
+class QLinuxFbDevice;
+
+class QLinuxFbDrmScreen : public QFbScreen
+{
+    Q_OBJECT
+public:
+    QLinuxFbDrmScreen(const QStringList &args);
+    ~QLinuxFbDrmScreen();
+
+    bool initialize() override;
+    QRegion doRedraw() override;
+    QPixmap grabWindow(WId wid, int x, int y, int width, int height) const override;
+
+private:
+    QKmsScreenConfig *m_screenConfig;
+    QLinuxFbDevice *m_device;
+};
+
+QT_END_NAMESPACE
+
+#endif // QLINUXFBDRMSCREEN_H
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp b/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
index c1c235588e..ce193bdf90 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
+++ b/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
@@ -39,6 +39,9 @@
 
 #include "qlinuxfbintegration.h"
 #include "qlinuxfbscreen.h"
+#if QT_CONFIG(kms)
+#include "qlinuxfbdrmscreen.h"
+#endif
 
 #include <QtFontDatabaseSupport/private/qgenericunixfontdatabase_p.h>
 #include <QtServiceSupport/private/qgenericunixservices_p.h>
@@ -69,10 +72,16 @@
 QT_BEGIN_NAMESPACE
 
 QLinuxFbIntegration::QLinuxFbIntegration(const QStringList &paramList)
-    : m_fontDb(new QGenericUnixFontDatabase),
+    : m_primaryScreen(nullptr),
+      m_fontDb(new QGenericUnixFontDatabase),
       m_services(new QGenericUnixServices)
 {
-    m_primaryScreen = new QLinuxFbScreen(paramList);
+#if QT_CONFIG(kms)
+    if (qEnvironmentVariableIntValue("QT_QPA_FB_DRM") != 0)
+        m_primaryScreen = new QLinuxFbDrmScreen(paramList);
+#endif
+    if (!m_primaryScreen)
+        m_primaryScreen = new QLinuxFbScreen(paramList);
 }
 
 QLinuxFbIntegration::~QLinuxFbIntegration()
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbintegration.h b/src/plugins/platforms/linuxfb/qlinuxfbintegration.h
index e48a1bae28..9934a8cd54 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbintegration.h
+++ b/src/plugins/platforms/linuxfb/qlinuxfbintegration.h
@@ -46,7 +46,7 @@
 QT_BEGIN_NAMESPACE
 
 class QAbstractEventDispatcher;
-class QLinuxFbScreen;
+class QFbScreen;
 class QFbVtHandler;
 
 class QLinuxFbIntegration : public QPlatformIntegration, public QPlatformNativeInterface
@@ -74,7 +74,7 @@ public:
 private:
     void createInputHandlers();
 
-    QLinuxFbScreen *m_primaryScreen;
+    QFbScreen *m_primaryScreen;
     QPlatformInputContext *m_inputContext;
     QScopedPointer<QPlatformFontDatabase> m_fontDb;
     QScopedPointer<QPlatformServices> m_services;
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbscreen.h b/src/plugins/platforms/linuxfb/qlinuxfbscreen.h
index 1e98191569..c7ce455e6a 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbscreen.h
+++ b/src/plugins/platforms/linuxfb/qlinuxfbscreen.h
@@ -54,11 +54,11 @@ public:
     QLinuxFbScreen(const QStringList &args);
     ~QLinuxFbScreen();
 
-    bool initialize();
+    bool initialize() override;
 
-    QPixmap grabWindow(WId wid, int x, int y, int width, int height) const Q_DECL_OVERRIDE;
+    QPixmap grabWindow(WId wid, int x, int y, int width, int height) const override;
 
-    QRegion doRedraw() Q_DECL_OVERRIDE;
+    QRegion doRedraw() override;
 
 private:
     QStringList mArgs;