media: stm32-dcmi: add media controller support

Add media controller support to dcmi in order
to walk within remote subdevices pipeline.
Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/Kconfig

@@ -121,7 +121,7 @@ config VIDEO_S3C_CAMIF
 
 config VIDEO_STM32_DCMI
 	tristate "STM32 Digital Camera Memory Interface (DCMI) support"
-	depends on VIDEO_V4L2 && OF
+	depends on VIDEO_V4L2 && OF && MEDIA_CONTROLLER
 	depends on ARCH_STM32 || COMPILE_TEST
 	select VIDEOBUF2_DMA_CONTIG
 	select V4L2_FWNODE

drivers/media/platform/stm32/stm32-dcmi.c

@@ -169,6 +169,9 @@ struct stm32_dcmi {
 
 	/* Ensure DMA operations atomicity */
 	struct mutex			dma_lock;
+
+	struct media_device		mdev;
+	struct media_pad		vid_cap_pad;
 };
 
 static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier *n)
@@ -1559,14 +1562,6 @@ static int dcmi_graph_notify_complete(struct v4l2_async_notifier *notifier)
 		return ret;
 	}
 
-	ret = video_register_device(dcmi->vdev, VFL_TYPE_GRABBER, -1);
-	if (ret) {
-		dev_err(dcmi->dev, "Failed to register video device\n");
-		return ret;
-	}
-
-	dev_dbg(dcmi->dev, "Device registered as %s\n",
-		video_device_node_name(dcmi->vdev));
 	return 0;
 }
 
@@ -1756,10 +1751,19 @@ static int dcmi_probe(struct platform_device *pdev)
 
 	q = &dcmi->queue;
 
+	dcmi->v4l2_dev.mdev = &dcmi->mdev;
+
+	/* Initialize media device */
+	strscpy(dcmi->mdev.model, DRV_NAME, sizeof(dcmi->mdev.model));
+	snprintf(dcmi->mdev.bus_info, sizeof(dcmi->mdev.bus_info),
+		 "platform:%s", DRV_NAME);
+	dcmi->mdev.dev = &pdev->dev;
+	media_device_init(&dcmi->mdev);
+
 	/* Initialize the top-level structure */
 	ret = v4l2_device_register(&pdev->dev, &dcmi->v4l2_dev);
 	if (ret)
-		goto err_dma_release;
+		goto err_media_device_cleanup;
 
 	dcmi->vdev = video_device_alloc();
 	if (!dcmi->vdev) {
@@ -1779,6 +1783,25 @@ static int dcmi_probe(struct platform_device *pdev)
 				  V4L2_CAP_READWRITE;
 	video_set_drvdata(dcmi->vdev, dcmi);
 
+	/* Media entity pads */
+	dcmi->vid_cap_pad.flags = MEDIA_PAD_FL_SINK;
+	ret = media_entity_pads_init(&dcmi->vdev->entity,
+				     1, &dcmi->vid_cap_pad);
+	if (ret) {
+		dev_err(dcmi->dev, "Failed to init media entity pad\n");
+		goto err_device_release;
+	}
+	dcmi->vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
+
+	ret = video_register_device(dcmi->vdev, VFL_TYPE_GRABBER, -1);
+	if (ret) {
+		dev_err(dcmi->dev, "Failed to register video device\n");
+		goto err_media_entity_cleanup;
+	}
+
+	dev_dbg(dcmi->dev, "Device registered as %s\n",
+		video_device_node_name(dcmi->vdev));
+
 	/* Buffer queue */
 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	q->io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF;
@@ -1794,12 +1817,12 @@ static int dcmi_probe(struct platform_device *pdev)
 	ret = vb2_queue_init(q);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Failed to initialize vb2 queue\n");
-		goto err_device_release;
+		goto err_media_entity_cleanup;
 	}
 
 	ret = dcmi_graph_init(dcmi);
 	if (ret < 0)
-		goto err_device_release;
+		goto err_media_entity_cleanup;
 
 	/* Reset device */
 	ret = reset_control_assert(dcmi->rstc);
@@ -1826,11 +1849,14 @@ static int dcmi_probe(struct platform_device *pdev)
 
 err_cleanup:
 	v4l2_async_notifier_cleanup(&dcmi->notifier);
+err_media_entity_cleanup:
+	media_entity_cleanup(&dcmi->vdev->entity);
 err_device_release:
 	video_device_release(dcmi->vdev);
 err_device_unregister:
 	v4l2_device_unregister(&dcmi->v4l2_dev);
-err_dma_release:
+err_media_device_cleanup:
+	media_device_cleanup(&dcmi->mdev);
 	dma_release_channel(dcmi->dma_chan);
 
 	return ret;
@@ -1844,7 +1870,9 @@ static int dcmi_remove(struct platform_device *pdev)
 
 	v4l2_async_notifier_unregister(&dcmi->notifier);
 	v4l2_async_notifier_cleanup(&dcmi->notifier);
+	media_entity_cleanup(&dcmi->vdev->entity);
 	v4l2_device_unregister(&dcmi->v4l2_dev);
+	media_device_cleanup(&dcmi->mdev);
 
 	dma_release_channel(dcmi->dma_chan);