Re: [PATCH v2 2/3] media: stm32-dcmi: add media controller support

Hi Hans,

On 6/20/19 2:01 PM, Hans Verkuil wrote:

On 6/11/19 10:48 AM, Hugues Fruchet wrote:

quoted

Add media controller support to dcmi.

Signed-off-by: Hugues Fruchet <redacted>
---
  drivers/media/platform/Kconfig            |  2 +-
  drivers/media/platform/stm32/stm32-dcmi.c | 83 +++++++++++++++++++++++--------
  2 files changed, 63 insertions(+), 22 deletions(-)

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index 8a19654..de7e21f 100644
--- a/drivers/media/platform/Kconfig
+++ b/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

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 7a4d559..3a69783 100644
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c

@@ -170,6 +170,9 @@ 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)

@@ -1545,21 +1548,12 @@ static int dcmi_graph_notify_complete(struct v4l2_async_notifier *notifier)
  		dev_err(dcmi->dev, "Could not get sensor bounds\n");
  		return ret;
  	}
-
  	ret = dcmi_set_default_fmt(dcmi);
  	if (ret) {
  		dev_err(dcmi->dev, "Could not set default format\n");
  		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;
-	}

Why was this moved to probe()? Off-hand I see no reason for that.

Regards,

	Hans

I need to do that otherwise the dcmi_graph_notify_bound() subdevice pad 
link code crashes:
  +	/*
  +	 * Link this sub-device to DCMI, it could be
  +	 * a parallel camera sensor or a bridge
  +	 */
  +	src_pad = media_entity_get_fwnode_pad(&subdev->entity,
  +					      subdev->fwnode,
  +					      MEDIA_PAD_FL_SOURCE);
  +
  +	ret = media_create_pad_link(&subdev->entity, src_pad,
  +				    &dcmi->vdev->entity, 0,
  +				    MEDIA_LNK_FL_IMMUTABLE |
  +				    MEDIA_LNK_FL_ENABLED);
see https://www.spinics.net/lists/linux-media/msg153120.html.

quoted

-
-	dev_dbg(dcmi->dev, "Device registered as %s\n",
-		video_device_node_name(dcmi->vdev));
  	return 0;
  }
  

@@ -1648,6 +1642,12 @@ static int dcmi_graph_init(struct stm32_dcmi *dcmi)
  	return 0;
  }
  
+static void dcmi_graph_deinit(struct stm32_dcmi *dcmi)
+{
+	v4l2_async_notifier_unregister(&dcmi->notifier);
+	v4l2_async_notifier_cleanup(&dcmi->notifier);
+}
+
  static int dcmi_probe(struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;

@@ -1752,10 +1752,27 @@ 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);
+
+	/* Register the media device */
+	ret = media_device_register(&dcmi->mdev);
+	if (ret) {
+		dev_err(dcmi->dev, "Failed to register media device (%d)\n",
+			ret);
+		goto err_media_device_cleanup;
+	}
+
  	/* Initialize the top-level structure */
  	ret = v4l2_device_register(&pdev->dev, &dcmi->v4l2_dev);
  	if (ret)
-		goto err_dma_release;
+		goto err_media_device_unregister;
  
  	dcmi->vdev = video_device_alloc();
  	if (!dcmi->vdev) {

@@ -1775,6 +1792,25 @@ 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_unregister;
+	}
+	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;

@@ -1790,18 +1826,18 @@ 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);
  	if (ret) {
  		dev_err(&pdev->dev, "Failed to assert the reset line\n");
-		goto err_cleanup;
+		goto err_graph_deinit;
  	}
  
  	usleep_range(3000, 5000);

@@ -1809,7 +1845,7 @@ static int dcmi_probe(struct platform_device *pdev)
  	ret = reset_control_deassert(dcmi->rstc);
  	if (ret) {
  		dev_err(&pdev->dev, "Failed to deassert the reset line\n");
-		goto err_cleanup;
+		goto err_graph_deinit;
  	}
  
  	dev_info(&pdev->dev, "Probe done\n");

@@ -1820,13 +1856,16 @@ static int dcmi_probe(struct platform_device *pdev)
  
  	return 0;
  
-err_cleanup:
-	v4l2_async_notifier_cleanup(&dcmi->notifier);
-err_device_release:
-	video_device_release(dcmi->vdev);
+err_graph_deinit:
+	dcmi_graph_deinit(dcmi);
+err_media_entity_cleanup:
+	media_entity_cleanup(&dcmi->vdev->entity);
  err_device_unregister:
  	v4l2_device_unregister(&dcmi->v4l2_dev);
-err_dma_release:
+err_media_device_unregister:
+	media_device_unregister(&dcmi->mdev);
+err_media_device_cleanup:
+	media_device_cleanup(&dcmi->mdev);
  	dma_release_channel(dcmi->dma_chan);
  
  	return ret;

@@ -1838,9 +1877,11 @@ static int dcmi_remove(struct platform_device *pdev)
  
  	pm_runtime_disable(&pdev->dev);
  
-	v4l2_async_notifier_unregister(&dcmi->notifier);
-	v4l2_async_notifier_cleanup(&dcmi->notifier);
+	dcmi_graph_deinit(dcmi);
+	media_entity_cleanup(&dcmi->vdev->entity);
  	v4l2_device_unregister(&dcmi->v4l2_dev);
+	media_device_unregister(&dcmi->mdev);
+	media_device_cleanup(&dcmi->mdev);
  
  	dma_release_channel(dcmi->dma_chan);
  

BR,
Hugues.
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