Device integration for DRM/KMS

Closes: #43

CMakeLists.txt

@@ -99,6 +99,9 @@ if(FEATURE_aurora_qpa)
         add_subdirectory(src/plugins/platforms/eglfs/deviceintegration/eglfs_x11)
     endif()
 endif()
+if(FEATURE_aurora_deviceintegration_drm)
+    add_subdirectory(src/plugins/deviceintegration/drm)
+endif()
 if(FEATURE_aurora_deviceintegration_wayland)
     add_subdirectory(src/plugins/deviceintegration/wayland)
 endif()

features.cmake

@@ -471,6 +471,35 @@ if(FEATURE_aurora_vulkan_server_buffer)
 endif()
 set(LIRI_FEATURE_aurora_vulkan_server_buffer "$<IF:${FEATURE_aurora_vulkan_server_buffer},1,0>")
 
+# Device Integration: drm
+option(FEATURE_aurora_deviceintegration_drm "Device Integration: drm" ON)
+if(FEATURE_aurora_deviceintegration_drm)
+    find_package(EGL QUIET)
+
+    if(NOT TARGET EGL::EGL)
+        message(WARNING "You need EGL for Aurora::DeviceIntegration::DRM")
+        set(FEATURE_aurora_deviceintegration_drm OFF)
+    endif()
+    if(NOT TARGET PkgConfig::Libudev)
+        message(WARNING "You need udev for Aurora::DeviceIntegration::DRM")
+	    set(FEATURE_aurora_deviceintegration_drm OFF)
+    endif()
+    if(NOT TARGET PkgConfig::Libinput)
+        message(WARNING "You need libinput for Aurora::DeviceIntegration::DRM")
+	    set(FEATURE_aurora_deviceintegration_drm OFF)
+    endif()
+    if(NOT TARGET PkgConfig::Libdrm)
+        message(WARNING "You need libdrm for Aurora::DeviceIntegration::DRM")
+	    set(FEATURE_aurora_deviceintegration_drm OFF)
+    endif()
+    if(NOT TARGET PkgConfig::Gbm)
+        message(WARNING "You need gbm for Aurora::DeviceIntegration::DRM")
+	    set(FEATURE_aurora_deviceintegration_drm OFF)
+    endif()
+endif()
+add_feature_info("Aurora::DeviceIntegration::DRM" FEATURE_aurora_deviceintegration_drm "Build DRM/KMS device integration")
+set(LIRI_FEATURE_aurora_deviceintegration_drm "$<IF:${FEATURE_aurora_deviceintegration_drm},1,0>")
+
 # Device Integration: wayland
 option(FEATURE_aurora_deviceintegration_wayland "Device Integration: wayland" ON)
 if(FEATURE_aurora_deviceintegration_wayland)

src/plugins/deviceintegration/drm/CMakeLists.txt

@@ -0,0 +1,38 @@
+include(ECMQtDeclareLoggingCategory)
+ecm_qt_declare_logging_category(
+    AuroraDeviceIntegrationDrm_SOURCES
+    HEADER "drmloggingcategories.h"
+    IDENTIFIER "Aurora::Platform::gLcDrm"
+    CATEGORY_NAME "aurora.platform.drm"
+    DEFAULT_SEVERITY "Info"
+    DESCRIPTION "Aurora device integration for DRM/KMS"
+)
+
+liri_add_plugin(AuroraDeviceIntegrationDrm
+    TYPE
+        "aurora/deviceintegration"
+    OUTPUT_NAME
+        drm
+    SOURCES
+        drm.json
+        drmbackend.cpp drmbackend.h
+        drmcursor.cpp drmcursor.h
+        drmgpu.cpp drmgpu.h
+        drmintegration.cpp drmintegration.h
+        drmintegrationplugin.cpp drmintegrationplugin.h
+        drmoutput.cpp drmoutput.h
+        drmwindow.cpp drmwindow.h
+        ${AuroraDeviceIntegrationDrm_SOURCES}
+    PUBLIC_LIBRARIES
+        Qt::Core
+        Qt::Gui
+        Liri::AuroraCore
+        Liri::AuroraPlatform
+        Liri::AuroraPlatformPrivate
+        Liri::AuroraUdev
+        EGL::EGL
+        PkgConfig::Libdrm
+        PkgConfig::Gbm
+)
+
+liri_finalize_plugin(AuroraDeviceIntegrationDrm)

src/plugins/deviceintegration/drm/drm.json

@@ -0,0 +1,3 @@
+{
+    "Keys": [ "drm" ]
+}

src/plugins/deviceintegration/drm/drmbackend.cpp

@@ -0,0 +1,199 @@
+// SPDX-FileCopyrightText: 2023 Pier Luigi Fiorini <[email protected]>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <LiriAuroraUdev/UdevEnumerate>
+
+#include "drmbackend.h"
+#include "drmgpu.h"
+#include "drmloggingcategories.h"
+#include "drmoutput.h"
+
+#include <sys/stat.h>
+
+#include <gbm.h>
+#include <libdrm/drm_mode.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#ifndef EGL_EXT_platform_base
+typedef EGLDisplay(EGLAPIENTRYP PFNEGLGETPLATFORMDISPLAYEXTPROC)(EGLenum platform,
+                                                                 void *native_display,
+                                                                 const EGLint *attrib_list);
+#endif
+
+#ifndef EGL_PLATFORM_GBM_KHR
+#  define EGL_PLATFORM_GBM_KHR 0x31D7
+#endif
+
+namespace Aurora {
+
+namespace Platform {
+
+Q_GLOBAL_STATIC(DrmBackend, gDrmBackend)
+
+DrmBackend::DrmBackend(QObject *parent)
+    : QObject(parent)
+    , m_session(Session::create(Session::Type::Logind, this))
+    , m_udev(new Aurora::PlatformSupport::Udev())
+{
+}
+
+DrmBackend::~DrmBackend()
+{
+    if (m_udev) {
+        delete m_udev;
+        m_udev = nullptr;
+    }
+}
+
+Session *DrmBackend::session() const
+{
+    return m_session;
+}
+
+EGLDisplay DrmBackend::eglDisplay() const
+{
+    return m_eglDisplay;
+}
+
+EGLNativeDisplayType DrmBackend::platformDisplay() const
+{
+    if (m_gpu)
+        return reinterpret_cast<EGLNativeDisplayType>(m_gpu->gbmDevice());
+    return EGL_CAST(EGLNativeDisplayType, 0);
+}
+
+DrmGpu *DrmBackend::primaryGpu() const
+{
+    return m_gpu;
+}
+
+void DrmBackend::initialize()
+{
+    if (m_initialized)
+        return;
+
+    m_initialized = true;
+
+    // Session
+    connect(m_session, &Session::devicePaused, this, [this](dev_t deviceId) {
+        if (auto *gpu = findGpu(deviceId))
+            gpu->setActive(false);
+    });
+    connect(m_session, &Session::deviceResumed, this, [this](dev_t deviceId) {
+        if (auto *gpu = findGpu(deviceId))
+            gpu->setActive(true);
+    });
+
+    // Find all GPUs
+    Aurora::PlatformSupport::UdevEnumerate enumerate(
+            Aurora::PlatformSupport::UdevDevice::PrimaryVideoDevice
+                    | Aurora::PlatformSupport::UdevDevice::GenericVideoDevice,
+            m_udev);
+    auto udevDevices = enumerate.scan();
+    if (Q_UNLIKELY(udevDevices.isEmpty()))
+        qFatal("Could not find DRM device!");
+
+    // Create GPUs
+    if (!udevDevices.isEmpty()) {
+        qCDebug(gLcDrm, "Found the following video devices for the \"%s\" seat:",
+                qPrintable(m_session->seat()));
+        for (auto *udevDevice : qAsConst(udevDevices)) {
+            if (udevDevice->seat() == m_session->seat()) {
+                const auto path = udevDevice->deviceNode();
+                qCDebug(gLcDrm) << '\t' << path.toLocal8Bit().constData();
+                addGpu(path);
+            }
+        }
+    }
+    if (Q_UNLIKELY(m_gpus.isEmpty()))
+        qFatal("No suitable DRM device have been found");
+
+    // Select the first one
+    m_gpu = m_gpus.first();
+
+    // Create EGL display
+    createDisplay();
+}
+
+void DrmBackend::destroy()
+{
+}
+
+DrmBackend *DrmBackend::instance()
+{
+    return gDrmBackend();
+}
+
+DrmGpu *DrmBackend::addGpu(const QString &path)
+{
+    // Open the DRM device
+    int fd = m_session->openRestricted(path);
+    if (fd < 0) {
+        qCWarning(gLcDrm) << "Failed to open DRM device" << path;
+        return nullptr;
+    }
+
+    // Make a simpel DRM call to check if the device is usable
+    drmModeResPtr resources = drmModeGetResources(fd);
+    if (!resources) {
+        qCDebug(gLcDrm) << "Skipping KMS incapable DRM device" << path;
+        m_session->closeRestricted(fd);
+        return nullptr;
+    }
+    drmModeFreeResources(resources);
+
+    struct stat sbuf;
+    if (fstat(fd, &sbuf) < 0) {
+        qCDebug(gLcDrm, "Failed to fstat \"%s\": %s", qPrintable(path), strerror(errno));
+        m_session->closeRestricted(fd);
+        return nullptr;
+    }
+
+    qCInfo(gLcDrm) << "Adding DRM device:" << path;
+
+    auto *gpu = new DrmGpu(path, fd, sbuf.st_rdev);
+    m_gpus.append(gpu);
+    emit gpuAdded(gpu);
+    return gpu;
+}
+
+DrmGpu *DrmBackend::findGpu(dev_t deviceId) const
+{
+    auto it = std::find_if(m_gpus.begin(), m_gpus.end(),
+                           [deviceId](const auto *gpu) { return gpu->deviceId() == deviceId; });
+    return it == m_gpus.end() ? nullptr : *it;
+}
+
+void DrmBackend::createDisplay()
+{
+    EGLNativeDisplayType nativeDisplay = platformDisplay();
+
+    PFNEGLGETPLATFORMDISPLAYEXTPROC getPlatformDisplay = nullptr;
+    const char *extensions = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
+    if (extensions
+        && (strstr(extensions, "EGL_KHR_platform_gbm")
+            || strstr(extensions, "EGL_MESA_platform_gbm"))) {
+        getPlatformDisplay = reinterpret_cast<PFNEGLGETPLATFORMDISPLAYEXTPROC>(
+                eglGetProcAddress("eglGetPlatformDisplayEXT"));
+    }
+
+    if (getPlatformDisplay) {
+        m_eglDisplay = getPlatformDisplay(EGL_PLATFORM_GBM_KHR, nativeDisplay, nullptr);
+    } else {
+        qCDebug(gLcDrm, "No eglGetPlatformDisplay for GBM, falling back to eglGetDisplay");
+        m_eglDisplay = eglGetDisplay(nativeDisplay);
+    }
+}
+
+void DrmBackend::addOutput(DrmOutput *output)
+{
+}
+
+void DrmBackend::removeOutput(DrmOutput *output)
+{
+}
+
+} // namespace Platform
+
+} // namespace Aurora

src/plugins/deviceintegration/drm/drmbackend.h

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2023 Pier Luigi Fiorini <[email protected]>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <QObject>
+
+#include <LiriAuroraPlatform/Session>
+#include <LiriAuroraUdev/Udev>
+
+#include <EGL/egl.h>
+
+namespace Aurora {
+
+namespace Platform {
+
+class DrmGpu;
+class DrmOutput;
+
+class DrmBackend : public QObject
+{
+    Q_OBJECT
+public:
+    explicit DrmBackend(QObject *parent = nullptr);
+    ~DrmBackend();
+
+    Session *session() const;
+
+    EGLDisplay eglDisplay() const;
+    EGLNativeDisplayType platformDisplay() const;
+
+    DrmGpu *primaryGpu() const;
+
+    void initialize();
+    void destroy();
+
+    static DrmBackend *instance();
+
+signals:
+    void gpuAdded(DrmGpu *gpu);
+    void gpuRemoved(DrmGpu *gpu);
+
+private:
+    bool m_initialized = false;
+    Session *m_session = nullptr;
+    Aurora::PlatformSupport::Udev *m_udev = nullptr;
+    DrmGpu *m_gpu = nullptr;
+    QList<DrmGpu *> m_gpus;
+    EGLDisplay m_eglDisplay = EGL_NO_DISPLAY;
+
+    DrmGpu *findGpu(dev_t deviceId) const;
+    DrmGpu *addGpu(const QString &path);
+
+    void createDisplay();
+
+private slots:
+    void addOutput(DrmOutput *output);
+    void removeOutput(DrmOutput *output);
+    void updateOutputs();
+};
+
+} // namespace Platform
+
+} // namespace Aurora