drm/exynos: support drm_wait_vblank feature for VIDI

this patch adds drm_wait_vblank support to Virtual Display module
so user can use DRM_IOCT_WAIT_VBLANK ioctl with this patch.
for this, you should set _DRM_VBLANK_EXYNOS_VIDI flags to
vblwait->request.type
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_vidi.c

@@ -56,6 +56,7 @@ struct vidi_context {
 	unsigned int			connected;
 	bool				vblank_on;
 	bool				suspended;
+	bool				direct_vblank;
 	struct work_struct		work;
 	struct mutex			lock;
 };
@@ -224,6 +225,15 @@ static int vidi_enable_vblank(struct device *dev)
 	if (!test_and_set_bit(0, &ctx->irq_flags))
 		ctx->vblank_on = true;
 
+	ctx->direct_vblank = true;
+
+	/*
+	 * in case of page flip request, vidi_finish_pageflip function
+	 * will not be called because direct_vblank is true and then
+	 * that function will be called by overlay_ops->commit callback
+	 */
+	schedule_work(&ctx->work);
+
 	return 0;
 }
 
@@ -425,7 +435,17 @@ static void vidi_fake_vblank_handler(struct work_struct *work)
 	/* refresh rate is about 50Hz. */
 	usleep_range(16000, 20000);
 
-	drm_handle_vblank(subdrv->drm_dev, manager->pipe);
+	mutex_lock(&ctx->lock);
+
+	if (ctx->direct_vblank) {
+		drm_handle_vblank(subdrv->drm_dev, manager->pipe);
+		ctx->direct_vblank = false;
+		mutex_unlock(&ctx->lock);
+		return;
+	}
+
+	mutex_unlock(&ctx->lock);
+
 	vidi_finish_pageflip(subdrv->drm_dev, manager->pipe);
 }
 

include/drm/exynos_drm.h

@@ -107,6 +107,16 @@ struct drm_exynos_vidi_connection {
 	uint64_t edid;
 };
 
+/* Indicate Exynos specific vblank flags */
+enum e_drm_exynos_vblank {
+	/*
+	 * this flags is used for Virtual Display module
+	 * to use DRM_IOCTL_WAIT_VBLANK feature. for this,
+	 * user should set this flag to vblwait->request.type
+	 */
+	_DRM_VBLANK_EXYNOS_VIDI	= 2,
+};
+
 /* memory type definitions. */
 enum e_drm_exynos_gem_mem_type {
 	/* Physically Continuous memory and used as default. */