[v10,01/13] media: staging/imx: refactor imx media device probe

Message ID 20190123105222.2378-2-rui.silva@linaro.org
State New
Headers show
Series
  • [v10,01/13] media: staging/imx: refactor imx media device probe
Related show

Commit Message

Rui Miguel Silva Jan. 23, 2019, 10:52 a.m.
Refactor and move media device initialization code to a new common
module, so it can be used by other devices, this will allow for example
a near to introduce imx7 CSI driver, to use this media device.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>

---
 drivers/staging/media/imx/Makefile            |   1 +
 .../staging/media/imx/imx-media-dev-common.c  | 102 ++++++++++++++++++
 drivers/staging/media/imx/imx-media-dev.c     |  88 ++++-----------
 drivers/staging/media/imx/imx-media-of.c      |   6 +-
 drivers/staging/media/imx/imx-media.h         |  15 +++
 5 files changed, 141 insertions(+), 71 deletions(-)
 create mode 100644 drivers/staging/media/imx/imx-media-dev-common.c

-- 
2.20.1

Comments

Sakari Ailus Jan. 24, 2019, 11:16 a.m. | #1
Hi Rui,

On Wed, Jan 23, 2019 at 10:52:10AM +0000, Rui Miguel Silva wrote:
> Refactor and move media device initialization code to a new common

> module, so it can be used by other devices, this will allow for example

> a near to introduce imx7 CSI driver, to use this media device.

> 

> Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>

> ---

>  drivers/staging/media/imx/Makefile            |   1 +

>  .../staging/media/imx/imx-media-dev-common.c  | 102 ++++++++++++++++++

>  drivers/staging/media/imx/imx-media-dev.c     |  88 ++++-----------

>  drivers/staging/media/imx/imx-media-of.c      |   6 +-

>  drivers/staging/media/imx/imx-media.h         |  15 +++

>  5 files changed, 141 insertions(+), 71 deletions(-)

>  create mode 100644 drivers/staging/media/imx/imx-media-dev-common.c

> 

> diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile

> index 698a4210316e..a30b3033f9a3 100644

> --- a/drivers/staging/media/imx/Makefile

> +++ b/drivers/staging/media/imx/Makefile

> @@ -1,5 +1,6 @@

>  # SPDX-License-Identifier: GPL-2.0

>  imx-media-objs := imx-media-dev.o imx-media-internal-sd.o imx-media-of.o

> +imx-media-objs += imx-media-dev-common.o

>  imx-media-common-objs := imx-media-utils.o imx-media-fim.o

>  imx-media-ic-objs := imx-ic-common.o imx-ic-prp.o imx-ic-prpencvf.o

>  

> diff --git a/drivers/staging/media/imx/imx-media-dev-common.c b/drivers/staging/media/imx/imx-media-dev-common.c

> new file mode 100644

> index 000000000000..55fe94fb72f2

> --- /dev/null

> +++ b/drivers/staging/media/imx/imx-media-dev-common.c

> @@ -0,0 +1,102 @@

> +// SPDX-License-Identifier: GPL

> +/*

> + * V4L2 Media Controller Driver for Freescale common i.MX5/6/7 SOC

> + *

> + * Copyright (c) 2018 Linaro Ltd

> + * Copyright (c) 2016 Mentor Graphics Inc.

> + */

> +

> +#include <linux/of_graph.h>

> +#include <linux/of_platform.h>

> +#include "imx-media.h"

> +

> +static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {

> +	.bound = imx_media_subdev_bound,

> +	.complete = imx_media_probe_complete,

> +};

> +

> +static const struct media_device_ops imx_media_md_ops = {

> +	.link_notify = imx_media_link_notify,

> +};

> +

> +struct imx_media_dev *imx_media_dev_init(struct device *dev)

> +{

> +	struct imx_media_dev *imxmd;

> +	int ret;

> +

> +	imxmd = devm_kzalloc(dev, sizeof(*imxmd), GFP_KERNEL);

> +	if (!imxmd)

> +		return ERR_PTR(-ENOMEM);

> +

> +	dev_set_drvdata(dev, imxmd);

> +

> +	strlcpy(imxmd->md.model, "imx-media", sizeof(imxmd->md.model));

> +	imxmd->md.ops = &imx_media_md_ops;

> +	imxmd->md.dev = dev;

> +

> +	mutex_init(&imxmd->mutex);

> +

> +	imxmd->v4l2_dev.mdev = &imxmd->md;

> +	strlcpy(imxmd->v4l2_dev.name, "imx-media",

> +		sizeof(imxmd->v4l2_dev.name));

> +

> +	media_device_init(&imxmd->md);

> +

> +	ret = v4l2_device_register(dev, &imxmd->v4l2_dev);

> +	if (ret < 0) {

> +		v4l2_err(&imxmd->v4l2_dev,

> +			 "Failed to register v4l2_device: %d\n", ret);

> +		goto cleanup;

> +	}

> +

> +	dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);

> +

> +	INIT_LIST_HEAD(&imxmd->vdev_list);

> +

> +	v4l2_async_notifier_init(&imxmd->notifier);

> +

> +	return imxmd;

> +

> +cleanup:

> +	media_device_cleanup(&imxmd->md);

> +

> +	return ERR_PTR(ret);

> +}

> +EXPORT_SYMBOL_GPL(imx_media_dev_init);

> +

> +int imx_media_dev_notifier_register(struct imx_media_dev *imxmd)

> +{

> +	int ret;

> +

> +	/* no subdevs? just bail */

> +	if (list_empty(&imxmd->notifier.asd_list)) {

> +		v4l2_err(&imxmd->v4l2_dev, "no subdevs\n");

> +		return -ENODEV;

> +	}

> +

> +	/* prepare the async subdev notifier and register it */

> +	imxmd->notifier.ops = &imx_media_subdev_ops;

> +	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,

> +					   &imxmd->notifier);

> +	if (ret) {

> +		v4l2_err(&imxmd->v4l2_dev,

> +			 "v4l2_async_notifier_register failed with %d\n", ret);

> +		return ret;

> +	}

> +

> +	return 0;

> +}

> +EXPORT_SYMBOL_GPL(imx_media_dev_notifier_register);

> +

> +void imx_media_dev_cleanup(struct imx_media_dev *imxmd)

> +{

> +	v4l2_device_unregister(&imxmd->v4l2_dev);

> +	media_device_cleanup(&imxmd->md);

> +}

> +EXPORT_SYMBOL_GPL(imx_media_dev_cleanup);

> +

> +void imx_media_dev_notifier_unregister(struct imx_media_dev *imxmd)

> +{

> +	v4l2_async_notifier_cleanup(&imxmd->notifier);


Is the naming of the function intentional? I'd say adding an oddly named
wrapper for v4l2_async_notifier_cleanup() hardly makes the code more
readable. I'd just call the function directly instead; same for
imx_media_dev_cleanup().

> +}

> +EXPORT_SYMBOL_GPL(imx_media_dev_notifier_unregister);

> diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c

> index 4b344a4a3706..21f65af5c738 100644

> --- a/drivers/staging/media/imx/imx-media-dev.c

> +++ b/drivers/staging/media/imx/imx-media-dev.c

> @@ -116,9 +116,9 @@ static int imx_media_get_ipu(struct imx_media_dev *imxmd,

>  }

>  

>  /* async subdev bound notifier */

> -static int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,

> -				  struct v4l2_subdev *sd,

> -				  struct v4l2_async_subdev *asd)

> +int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,

> +			   struct v4l2_subdev *sd,

> +			   struct v4l2_async_subdev *asd)

>  {

>  	struct imx_media_dev *imxmd = notifier2dev(notifier);

>  	int ret = 0;

> @@ -302,7 +302,7 @@ static int imx_media_create_pad_vdev_lists(struct imx_media_dev *imxmd)

>  }

>  

>  /* async subdev complete notifier */

> -static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)

> +int imx_media_probe_complete(struct v4l2_async_notifier *notifier)

>  {

>  	struct imx_media_dev *imxmd = notifier2dev(notifier);

>  	int ret;

> @@ -326,11 +326,6 @@ static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)

>  	return media_device_register(&imxmd->md);

>  }

>  

> -static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {

> -	.bound = imx_media_subdev_bound,

> -	.complete = imx_media_probe_complete,

> -};

> -

>  /*

>   * adds controls to a video device from an entity subdevice.

>   * Continues upstream from the entity's sink pads.

> @@ -374,8 +369,8 @@ static int imx_media_inherit_controls(struct imx_media_dev *imxmd,

>  	return ret;

>  }

>  

> -static int imx_media_link_notify(struct media_link *link, u32 flags,

> -				 unsigned int notification)

> +int imx_media_link_notify(struct media_link *link, u32 flags,

> +			  unsigned int notification)

>  {

>  	struct media_entity *source = link->source->entity;

>  	struct imx_media_pad_vdev *pad_vdev;

> @@ -438,10 +433,6 @@ static int imx_media_link_notify(struct media_link *link, u32 flags,

>  	return ret;

>  }

>  

> -static const struct media_device_ops imx_media_md_ops = {

> -	.link_notify = imx_media_link_notify,

> -};

> -

>  static int imx_media_probe(struct platform_device *pdev)

>  {

>  	struct device *dev = &pdev->dev;

> @@ -449,76 +440,36 @@ static int imx_media_probe(struct platform_device *pdev)

>  	struct imx_media_dev *imxmd;

>  	int ret;

>  

> -	imxmd = devm_kzalloc(dev, sizeof(*imxmd), GFP_KERNEL);

> -	if (!imxmd)

> -		return -ENOMEM;

> -

> -	dev_set_drvdata(dev, imxmd);

> -

> -	strscpy(imxmd->md.model, "imx-media", sizeof(imxmd->md.model));

> -	imxmd->md.ops = &imx_media_md_ops;

> -	imxmd->md.dev = dev;

> -

> -	mutex_init(&imxmd->mutex);

> -

> -	imxmd->v4l2_dev.mdev = &imxmd->md;

> -	strscpy(imxmd->v4l2_dev.name, "imx-media",

> -		sizeof(imxmd->v4l2_dev.name));

> -

> -	media_device_init(&imxmd->md);

> -

> -	ret = v4l2_device_register(dev, &imxmd->v4l2_dev);

> -	if (ret < 0) {

> -		v4l2_err(&imxmd->v4l2_dev,

> -			 "Failed to register v4l2_device: %d\n", ret);

> -		goto cleanup;

> -	}

> -

> -	dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);

> -

> -	INIT_LIST_HEAD(&imxmd->vdev_list);

> -

> -	v4l2_async_notifier_init(&imxmd->notifier);

> +	imxmd = imx_media_dev_init(dev);

> +	if (IS_ERR(imxmd))

> +		return PTR_ERR(imxmd);

>  

>  	ret = imx_media_add_of_subdevs(imxmd, node);

>  	if (ret) {

>  		v4l2_err(&imxmd->v4l2_dev,

>  			 "add_of_subdevs failed with %d\n", ret);

> -		goto notifier_cleanup;

> +		goto dev_cleanup;

>  	}

>  

>  	ret = imx_media_add_internal_subdevs(imxmd);

>  	if (ret) {

>  		v4l2_err(&imxmd->v4l2_dev,

>  			 "add_internal_subdevs failed with %d\n", ret);

> -		goto notifier_cleanup;

> -	}

> -

> -	/* no subdevs? just bail */

> -	if (list_empty(&imxmd->notifier.asd_list)) {

> -		ret = -ENODEV;

> -		goto notifier_cleanup;

> +		goto dev_cleanup;

>  	}

>  

> -	/* prepare the async subdev notifier and register it */

> -	imxmd->notifier.ops = &imx_media_subdev_ops;

> -	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,

> -					   &imxmd->notifier);

> -	if (ret) {

> -		v4l2_err(&imxmd->v4l2_dev,

> -			 "v4l2_async_notifier_register failed with %d\n", ret);

> +	ret = imx_media_dev_notifier_register(imxmd);

> +	if (ret)

>  		goto del_int;

> -	}

>  

>  	return 0;

>  

>  del_int:

>  	imx_media_remove_internal_subdevs(imxmd);

> -notifier_cleanup:

> -	v4l2_async_notifier_cleanup(&imxmd->notifier);


If you remove this one, you'll miss cleaning up the notifier afterwards: an
initialised async notifier needs to be cleaned up in the end.

> -	v4l2_device_unregister(&imxmd->v4l2_dev);

> -cleanup:

> -	media_device_cleanup(&imxmd->md);

> +

> +dev_cleanup:

> +	imx_media_dev_cleanup(imxmd);

> +

>  	return ret;

>  }

>  

> @@ -531,10 +482,9 @@ static int imx_media_remove(struct platform_device *pdev)

>  

>  	v4l2_async_notifier_unregister(&imxmd->notifier);

>  	imx_media_remove_internal_subdevs(imxmd);

> -	v4l2_async_notifier_cleanup(&imxmd->notifier);

> -	v4l2_device_unregister(&imxmd->v4l2_dev);

> +	imx_media_dev_notifier_unregister(imxmd);

>  	media_device_unregister(&imxmd->md);

> -	media_device_cleanup(&imxmd->md);

> +	imx_media_dev_cleanup(imxmd);

>  

>  	return 0;

>  }

> diff --git a/drivers/staging/media/imx/imx-media-of.c b/drivers/staging/media/imx/imx-media-of.c

> index a01327f6e045..03446335ac03 100644

> --- a/drivers/staging/media/imx/imx-media-of.c

> +++ b/drivers/staging/media/imx/imx-media-of.c

> @@ -20,7 +20,8 @@

>  #include <video/imx-ipu-v3.h>

>  #include "imx-media.h"

>  

> -static int of_add_csi(struct imx_media_dev *imxmd, struct device_node *csi_np)

> +int imx_media_of_add_csi(struct imx_media_dev *imxmd,

> +			 struct device_node *csi_np)

>  {

>  	int ret;

>  

> @@ -45,6 +46,7 @@ static int of_add_csi(struct imx_media_dev *imxmd, struct device_node *csi_np)

>  

>  	return 0;

>  }

> +EXPORT_SYMBOL_GPL(imx_media_of_add_csi);

>  

>  int imx_media_add_of_subdevs(struct imx_media_dev *imxmd,

>  			     struct device_node *np)

> @@ -57,7 +59,7 @@ int imx_media_add_of_subdevs(struct imx_media_dev *imxmd,

>  		if (!csi_np)

>  			break;

>  

> -		ret = of_add_csi(imxmd, csi_np);

> +		ret = imx_media_of_add_csi(imxmd, csi_np);

>  		of_node_put(csi_np);

>  		if (ret)

>  			return ret;

> diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h

> index bc7feb81937c..b7f11c36461b 100644

> --- a/drivers/staging/media/imx/imx-media.h

> +++ b/drivers/staging/media/imx/imx-media.h

> @@ -226,6 +226,19 @@ int imx_media_add_async_subdev(struct imx_media_dev *imxmd,

>  			       struct fwnode_handle *fwnode,

>  			       struct platform_device *pdev);

>  

> +int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,

> +			   struct v4l2_subdev *sd,

> +			   struct v4l2_async_subdev *asd);

> +int imx_media_link_notify(struct media_link *link, u32 flags,

> +			  unsigned int notification);

> +int imx_media_probe_complete(struct v4l2_async_notifier *notifier);

> +

> +struct imx_media_dev *imx_media_dev_init(struct device *dev);

> +int imx_media_dev_notifier_register(struct imx_media_dev *imxmd);

> +

> +void imx_media_dev_cleanup(struct imx_media_dev *imxmd);

> +void imx_media_dev_notifier_unregister(struct imx_media_dev *imxmd);

> +

>  /* imx-media-fim.c */

>  struct imx_media_fim;

>  void imx_media_fim_eof_monitor(struct imx_media_fim *fim, ktime_t timestamp);

> @@ -249,6 +262,8 @@ int imx_media_create_of_links(struct imx_media_dev *imxmd,

>  			      struct v4l2_subdev *sd);

>  int imx_media_create_csi_of_links(struct imx_media_dev *imxmd,

>  				  struct v4l2_subdev *csi);

> +int imx_media_of_add_csi(struct imx_media_dev *imxmd,

> +			 struct device_node *csi_np);

>  

>  /* imx-media-capture.c */

>  struct imx_media_video_dev *


-- 
Kind regards,

Sakari Ailus
sakari.ailus@linux.intel.com

Patch

diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile
index 698a4210316e..a30b3033f9a3 100644
--- a/drivers/staging/media/imx/Makefile
+++ b/drivers/staging/media/imx/Makefile
@@ -1,5 +1,6 @@ 
 # SPDX-License-Identifier: GPL-2.0
 imx-media-objs := imx-media-dev.o imx-media-internal-sd.o imx-media-of.o
+imx-media-objs += imx-media-dev-common.o
 imx-media-common-objs := imx-media-utils.o imx-media-fim.o
 imx-media-ic-objs := imx-ic-common.o imx-ic-prp.o imx-ic-prpencvf.o
 
diff --git a/drivers/staging/media/imx/imx-media-dev-common.c b/drivers/staging/media/imx/imx-media-dev-common.c
new file mode 100644
index 000000000000..55fe94fb72f2
--- /dev/null
+++ b/drivers/staging/media/imx/imx-media-dev-common.c
@@ -0,0 +1,102 @@ 
+// SPDX-License-Identifier: GPL
+/*
+ * V4L2 Media Controller Driver for Freescale common i.MX5/6/7 SOC
+ *
+ * Copyright (c) 2018 Linaro Ltd
+ * Copyright (c) 2016 Mentor Graphics Inc.
+ */
+
+#include <linux/of_graph.h>
+#include <linux/of_platform.h>
+#include "imx-media.h"
+
+static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {
+	.bound = imx_media_subdev_bound,
+	.complete = imx_media_probe_complete,
+};
+
+static const struct media_device_ops imx_media_md_ops = {
+	.link_notify = imx_media_link_notify,
+};
+
+struct imx_media_dev *imx_media_dev_init(struct device *dev)
+{
+	struct imx_media_dev *imxmd;
+	int ret;
+
+	imxmd = devm_kzalloc(dev, sizeof(*imxmd), GFP_KERNEL);
+	if (!imxmd)
+		return ERR_PTR(-ENOMEM);
+
+	dev_set_drvdata(dev, imxmd);
+
+	strlcpy(imxmd->md.model, "imx-media", sizeof(imxmd->md.model));
+	imxmd->md.ops = &imx_media_md_ops;
+	imxmd->md.dev = dev;
+
+	mutex_init(&imxmd->mutex);
+
+	imxmd->v4l2_dev.mdev = &imxmd->md;
+	strlcpy(imxmd->v4l2_dev.name, "imx-media",
+		sizeof(imxmd->v4l2_dev.name));
+
+	media_device_init(&imxmd->md);
+
+	ret = v4l2_device_register(dev, &imxmd->v4l2_dev);
+	if (ret < 0) {
+		v4l2_err(&imxmd->v4l2_dev,
+			 "Failed to register v4l2_device: %d\n", ret);
+		goto cleanup;
+	}
+
+	dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);
+
+	INIT_LIST_HEAD(&imxmd->vdev_list);
+
+	v4l2_async_notifier_init(&imxmd->notifier);
+
+	return imxmd;
+
+cleanup:
+	media_device_cleanup(&imxmd->md);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(imx_media_dev_init);
+
+int imx_media_dev_notifier_register(struct imx_media_dev *imxmd)
+{
+	int ret;
+
+	/* no subdevs? just bail */
+	if (list_empty(&imxmd->notifier.asd_list)) {
+		v4l2_err(&imxmd->v4l2_dev, "no subdevs\n");
+		return -ENODEV;
+	}
+
+	/* prepare the async subdev notifier and register it */
+	imxmd->notifier.ops = &imx_media_subdev_ops;
+	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,
+					   &imxmd->notifier);
+	if (ret) {
+		v4l2_err(&imxmd->v4l2_dev,
+			 "v4l2_async_notifier_register failed with %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(imx_media_dev_notifier_register);
+
+void imx_media_dev_cleanup(struct imx_media_dev *imxmd)
+{
+	v4l2_device_unregister(&imxmd->v4l2_dev);
+	media_device_cleanup(&imxmd->md);
+}
+EXPORT_SYMBOL_GPL(imx_media_dev_cleanup);
+
+void imx_media_dev_notifier_unregister(struct imx_media_dev *imxmd)
+{
+	v4l2_async_notifier_cleanup(&imxmd->notifier);
+}
+EXPORT_SYMBOL_GPL(imx_media_dev_notifier_unregister);
diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index 4b344a4a3706..21f65af5c738 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -116,9 +116,9 @@  static int imx_media_get_ipu(struct imx_media_dev *imxmd,
 }
 
 /* async subdev bound notifier */
-static int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,
-				  struct v4l2_subdev *sd,
-				  struct v4l2_async_subdev *asd)
+int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,
+			   struct v4l2_subdev *sd,
+			   struct v4l2_async_subdev *asd)
 {
 	struct imx_media_dev *imxmd = notifier2dev(notifier);
 	int ret = 0;
@@ -302,7 +302,7 @@  static int imx_media_create_pad_vdev_lists(struct imx_media_dev *imxmd)
 }
 
 /* async subdev complete notifier */
-static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)
+int imx_media_probe_complete(struct v4l2_async_notifier *notifier)
 {
 	struct imx_media_dev *imxmd = notifier2dev(notifier);
 	int ret;
@@ -326,11 +326,6 @@  static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)
 	return media_device_register(&imxmd->md);
 }
 
-static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {
-	.bound = imx_media_subdev_bound,
-	.complete = imx_media_probe_complete,
-};
-
 /*
  * adds controls to a video device from an entity subdevice.
  * Continues upstream from the entity's sink pads.
@@ -374,8 +369,8 @@  static int imx_media_inherit_controls(struct imx_media_dev *imxmd,
 	return ret;
 }
 
-static int imx_media_link_notify(struct media_link *link, u32 flags,
-				 unsigned int notification)
+int imx_media_link_notify(struct media_link *link, u32 flags,
+			  unsigned int notification)
 {
 	struct media_entity *source = link->source->entity;
 	struct imx_media_pad_vdev *pad_vdev;
@@ -438,10 +433,6 @@  static int imx_media_link_notify(struct media_link *link, u32 flags,
 	return ret;
 }
 
-static const struct media_device_ops imx_media_md_ops = {
-	.link_notify = imx_media_link_notify,
-};
-
 static int imx_media_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -449,76 +440,36 @@  static int imx_media_probe(struct platform_device *pdev)
 	struct imx_media_dev *imxmd;
 	int ret;
 
-	imxmd = devm_kzalloc(dev, sizeof(*imxmd), GFP_KERNEL);
-	if (!imxmd)
-		return -ENOMEM;
-
-	dev_set_drvdata(dev, imxmd);
-
-	strscpy(imxmd->md.model, "imx-media", sizeof(imxmd->md.model));
-	imxmd->md.ops = &imx_media_md_ops;
-	imxmd->md.dev = dev;
-
-	mutex_init(&imxmd->mutex);
-
-	imxmd->v4l2_dev.mdev = &imxmd->md;
-	strscpy(imxmd->v4l2_dev.name, "imx-media",
-		sizeof(imxmd->v4l2_dev.name));
-
-	media_device_init(&imxmd->md);
-
-	ret = v4l2_device_register(dev, &imxmd->v4l2_dev);
-	if (ret < 0) {
-		v4l2_err(&imxmd->v4l2_dev,
-			 "Failed to register v4l2_device: %d\n", ret);
-		goto cleanup;
-	}
-
-	dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);
-
-	INIT_LIST_HEAD(&imxmd->vdev_list);
-
-	v4l2_async_notifier_init(&imxmd->notifier);
+	imxmd = imx_media_dev_init(dev);
+	if (IS_ERR(imxmd))
+		return PTR_ERR(imxmd);
 
 	ret = imx_media_add_of_subdevs(imxmd, node);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
 			 "add_of_subdevs failed with %d\n", ret);
-		goto notifier_cleanup;
+		goto dev_cleanup;
 	}
 
 	ret = imx_media_add_internal_subdevs(imxmd);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
 			 "add_internal_subdevs failed with %d\n", ret);
-		goto notifier_cleanup;
-	}
-
-	/* no subdevs? just bail */
-	if (list_empty(&imxmd->notifier.asd_list)) {
-		ret = -ENODEV;
-		goto notifier_cleanup;
+		goto dev_cleanup;
 	}
 
-	/* prepare the async subdev notifier and register it */
-	imxmd->notifier.ops = &imx_media_subdev_ops;
-	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,
-					   &imxmd->notifier);
-	if (ret) {
-		v4l2_err(&imxmd->v4l2_dev,
-			 "v4l2_async_notifier_register failed with %d\n", ret);
+	ret = imx_media_dev_notifier_register(imxmd);
+	if (ret)
 		goto del_int;
-	}
 
 	return 0;
 
 del_int:
 	imx_media_remove_internal_subdevs(imxmd);
-notifier_cleanup:
-	v4l2_async_notifier_cleanup(&imxmd->notifier);
-	v4l2_device_unregister(&imxmd->v4l2_dev);
-cleanup:
-	media_device_cleanup(&imxmd->md);
+
+dev_cleanup:
+	imx_media_dev_cleanup(imxmd);
+
 	return ret;
 }
 
@@ -531,10 +482,9 @@  static int imx_media_remove(struct platform_device *pdev)
 
 	v4l2_async_notifier_unregister(&imxmd->notifier);
 	imx_media_remove_internal_subdevs(imxmd);
-	v4l2_async_notifier_cleanup(&imxmd->notifier);
-	v4l2_device_unregister(&imxmd->v4l2_dev);
+	imx_media_dev_notifier_unregister(imxmd);
 	media_device_unregister(&imxmd->md);
-	media_device_cleanup(&imxmd->md);
+	imx_media_dev_cleanup(imxmd);
 
 	return 0;
 }
diff --git a/drivers/staging/media/imx/imx-media-of.c b/drivers/staging/media/imx/imx-media-of.c
index a01327f6e045..03446335ac03 100644
--- a/drivers/staging/media/imx/imx-media-of.c
+++ b/drivers/staging/media/imx/imx-media-of.c
@@ -20,7 +20,8 @@ 
 #include <video/imx-ipu-v3.h>
 #include "imx-media.h"
 
-static int of_add_csi(struct imx_media_dev *imxmd, struct device_node *csi_np)
+int imx_media_of_add_csi(struct imx_media_dev *imxmd,
+			 struct device_node *csi_np)
 {
 	int ret;
 
@@ -45,6 +46,7 @@  static int of_add_csi(struct imx_media_dev *imxmd, struct device_node *csi_np)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(imx_media_of_add_csi);
 
 int imx_media_add_of_subdevs(struct imx_media_dev *imxmd,
 			     struct device_node *np)
@@ -57,7 +59,7 @@  int imx_media_add_of_subdevs(struct imx_media_dev *imxmd,
 		if (!csi_np)
 			break;
 
-		ret = of_add_csi(imxmd, csi_np);
+		ret = imx_media_of_add_csi(imxmd, csi_np);
 		of_node_put(csi_np);
 		if (ret)
 			return ret;
diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h
index bc7feb81937c..b7f11c36461b 100644
--- a/drivers/staging/media/imx/imx-media.h
+++ b/drivers/staging/media/imx/imx-media.h
@@ -226,6 +226,19 @@  int imx_media_add_async_subdev(struct imx_media_dev *imxmd,
 			       struct fwnode_handle *fwnode,
 			       struct platform_device *pdev);
 
+int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,
+			   struct v4l2_subdev *sd,
+			   struct v4l2_async_subdev *asd);
+int imx_media_link_notify(struct media_link *link, u32 flags,
+			  unsigned int notification);
+int imx_media_probe_complete(struct v4l2_async_notifier *notifier);
+
+struct imx_media_dev *imx_media_dev_init(struct device *dev);
+int imx_media_dev_notifier_register(struct imx_media_dev *imxmd);
+
+void imx_media_dev_cleanup(struct imx_media_dev *imxmd);
+void imx_media_dev_notifier_unregister(struct imx_media_dev *imxmd);
+
 /* imx-media-fim.c */
 struct imx_media_fim;
 void imx_media_fim_eof_monitor(struct imx_media_fim *fim, ktime_t timestamp);
@@ -249,6 +262,8 @@  int imx_media_create_of_links(struct imx_media_dev *imxmd,
 			      struct v4l2_subdev *sd);
 int imx_media_create_csi_of_links(struct imx_media_dev *imxmd,
 				  struct v4l2_subdev *csi);
+int imx_media_of_add_csi(struct imx_media_dev *imxmd,
+			 struct device_node *csi_np);
 
 /* imx-media-capture.c */
 struct imx_media_video_dev *