[v5,4/4] media: platform: Add Renesas RZ/G2L CRU driver

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Add v4l driver for Renesas RZ/G2L Camera data Receiving Unit.

Based on a patch in the BSP by Hien Huynh
<hien.huynh.px@renesas.com>

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
-v4 -> v5
* Made sure we call pre_streamon/post_streamoff around s_stream
* Made sure to cleanup on error path in s_stream
* Dropped pre_streamon/post_streamoff callbacks from IP subdev
* Moved the CRU start/stop configuration to IP subdev to avoid
  recursively calling pre_streamon/post_streamoff callbacks.

-v3 -> v4
* Undoing the configuration in case s_stream(1) fails
* Made sure we call post_streamoff in the error path of s_stream(1)

v2 -> v3
* Switched to PM runtime
* Modeled CRU IP block as a subdev
* Dropped explicitly selecting VIDEO_RZG2L_CSI2 for VIDEO_RZG2L_CRU config
* Replaced v4l2_dev_to_cru macro with inline function notifier_to_cru()
* Dropped id parameter from rvin_mc_parse_of()
* Renamed rzg2l_cru_csi2_init() -> rzg2l_cru_media_init()
* Used dev_err_probe() in rzg2l_cru_probe()
* Replaced devm_reset_control_get() -> devm_reset_control_get_exclusive()
* Prefixed HW_BUFFER_MAX and HW_BUFFER_DEFAULT macros with RZG2L_CRU_
* Moved asserting presetn signal from rzg2l_cru_dma_register() to rzg2l_cru_start_streaming_vq()
* Dropped VB2_READ from VB2 io_modes
* Used dev_dbg() in rzg2l_cru_video_register() and rzg2l_cru_video_unregister()
* Got rid of rzg2l_cru_notify()
* Dropped V4L2_CAP_READWRITE from device caps
* Introduced rzg2l_cru_v4l2_init() for initialization.
* Got rid v4l2_pipeline_pm_get() and used PM in ov5645 sensor driver. Patch posted 
  https://patchwork.linuxtv.org/project/linux-media/patch/20220927201634.750141-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

v1 -> v2
* No change

RFC v2 -> v1
* Moved the driver to renesas folder 
* Fixed review comments pointed by Jacopo

RFC v1 -> RFC v2
* Dropped group
* Dropped CSI subdev and implemented as new driver
* Dropped "mc_" from function names
* Moved the driver to renesas folder
---
 .../media/platform/renesas/rzg2l-cru/Kconfig  |   16 +
 .../media/platform/renesas/rzg2l-cru/Makefile |    3 +
 .../platform/renesas/rzg2l-cru/rzg2l-core.c   |  370 ++++++
 .../platform/renesas/rzg2l-cru/rzg2l-cru.h    |  169 +++
 .../platform/renesas/rzg2l-cru/rzg2l-ip.c     |  283 +++++
 .../platform/renesas/rzg2l-cru/rzg2l-video.c  | 1086 +++++++++++++++++
 6 files changed, 1927 insertions(+)
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
 create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c

Hi Prabhakar,

Thank you for the patch.

On Wed, Nov 02, 2022 at 12:43:29AM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Add v4l driver for Renesas RZ/G2L Camera data Receiving Unit.
> 
> Based on a patch in the BSP by Hien Huynh
> <hien.huynh.px@renesas.com>
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> -v4 -> v5
> * Made sure we call pre_streamon/post_streamoff around s_stream
> * Made sure to cleanup on error path in s_stream
> * Dropped pre_streamon/post_streamoff callbacks from IP subdev
> * Moved the CRU start/stop configuration to IP subdev to avoid
>   recursively calling pre_streamon/post_streamoff callbacks.
> 
> -v3 -> v4
> * Undoing the configuration in case s_stream(1) fails
> * Made sure we call post_streamoff in the error path of s_stream(1)
> 
> v2 -> v3
> * Switched to PM runtime
> * Modeled CRU IP block as a subdev
> * Dropped explicitly selecting VIDEO_RZG2L_CSI2 for VIDEO_RZG2L_CRU config
> * Replaced v4l2_dev_to_cru macro with inline function notifier_to_cru()
> * Dropped id parameter from rvin_mc_parse_of()
> * Renamed rzg2l_cru_csi2_init() -> rzg2l_cru_media_init()
> * Used dev_err_probe() in rzg2l_cru_probe()
> * Replaced devm_reset_control_get() -> devm_reset_control_get_exclusive()
> * Prefixed HW_BUFFER_MAX and HW_BUFFER_DEFAULT macros with RZG2L_CRU_
> * Moved asserting presetn signal from rzg2l_cru_dma_register() to rzg2l_cru_start_streaming_vq()
> * Dropped VB2_READ from VB2 io_modes
> * Used dev_dbg() in rzg2l_cru_video_register() and rzg2l_cru_video_unregister()
> * Got rid of rzg2l_cru_notify()
> * Dropped V4L2_CAP_READWRITE from device caps
> * Introduced rzg2l_cru_v4l2_init() for initialization.
> * Got rid v4l2_pipeline_pm_get() and used PM in ov5645 sensor driver. Patch posted 
>   https://patchwork.linuxtv.org/project/linux-media/patch/20220927201634.750141-1-prabhakar.mahadev-lad.rj@bp.renesas.com/
> 
> v1 -> v2
> * No change
> 
> RFC v2 -> v1
> * Moved the driver to renesas folder 
> * Fixed review comments pointed by Jacopo
> 
> RFC v1 -> RFC v2
> * Dropped group
> * Dropped CSI subdev and implemented as new driver
> * Dropped "mc_" from function names
> * Moved the driver to renesas folder
> ---
>  .../media/platform/renesas/rzg2l-cru/Kconfig  |   16 +
>  .../media/platform/renesas/rzg2l-cru/Makefile |    3 +
>  .../platform/renesas/rzg2l-cru/rzg2l-core.c   |  370 ++++++
>  .../platform/renesas/rzg2l-cru/rzg2l-cru.h    |  169 +++
>  .../platform/renesas/rzg2l-cru/rzg2l-ip.c     |  283 +++++
>  .../platform/renesas/rzg2l-cru/rzg2l-video.c  | 1086 +++++++++++++++++
>  6 files changed, 1927 insertions(+)
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
>  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> 
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/Kconfig b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> index 57c40bb499df..b39818c1f053 100644
> --- a/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> +++ b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> @@ -15,3 +15,19 @@ config VIDEO_RZG2L_CSI2
>  
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called rzg2l-csi2.
> +
> +config VIDEO_RZG2L_CRU
> +	tristate "RZ/G2L Camera Receiving Unit (CRU) Driver"
> +	depends on ARCH_RENESAS || COMPILE_TEST
> +	depends on V4L_PLATFORM_DRIVERS
> +	depends on VIDEO_DEV && OF
> +	select MEDIA_CONTROLLER
> +	select V4L2_FWNODE
> +	select VIDEOBUF2_DMA_CONTIG
> +	select VIDEO_V4L2_SUBDEV_API
> +	help
> +	  Support for Renesas RZ/G2L (and alike SoC's) Camera Receiving
> +	  Unit (CRU) driver.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called rzg2l-cru.
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/Makefile b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> index 91ea97a944e6..c4db2632874f 100644
> --- a/drivers/media/platform/renesas/rzg2l-cru/Makefile
> +++ b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> @@ -1,3 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
>  obj-$(CONFIG_VIDEO_RZG2L_CSI2) += rzg2l-csi2.o
> +
> +rzg2l-cru-objs = rzg2l-core.o rzg2l-ip.o rzg2l-video.o
> +obj-$(CONFIG_VIDEO_RZG2L_CRU) += rzg2l-cru.o
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
> new file mode 100644
> index 000000000000..7a92fcfee84c
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
> @@ -0,0 +1,370 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Driver for Renesas RZ/G2L CRU
> + *
> + * Copyright (C) 2022 Renesas Electronics Corp.
> + *
> + * Based on Renesas R-Car VIN
> + * Copyright (C) 2011-2013 Renesas Solutions Corp.
> + * Copyright (C) 2013 Cogent Embedded, Inc., <source@cogentembedded.com>
> + * Copyright (C) 2008 Magnus Damm
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mc.h>
> +
> +#include "rzg2l-cru.h"
> +
> +static inline struct rzg2l_cru_dev *notifier_to_cru(struct v4l2_async_notifier *n)
> +{
> +	return container_of(n, struct rzg2l_cru_dev, notifier);
> +}
> +
> +static int rzg2l_cru_csi2_link_notify(struct media_link *link, u32 flags,
> +				      unsigned int notification)
> +{
> +	struct media_entity *entity;
> +	struct rzg2l_cru_dev *cru;
> +	int ret;
> +
> +	ret = v4l2_pipeline_link_notify(link, flags, notification);
> +	if (ret)
> +		return ret;
> +
> +	/* Only care about link enablement for CRU nodes. */
> +	if (!(flags & MEDIA_LNK_FL_ENABLED))
> +		return 0;
> +
> +	cru = container_of(link->graph_obj.mdev, struct rzg2l_cru_dev, mdev);
> +	/*
> +	 * Don't allow link changes if any entity in the graph is
> +	 * streaming, modifying the CHSEL register fields can disrupt
> +	 * running streams.
> +	 */
> +	media_device_for_each_entity(entity, &cru->mdev)
> +		if (media_entity_is_streaming(entity))
> +			return -EBUSY;
> +
> +	mutex_lock(&cru->mdev_lock);
> +	if (media_pad_remote_pad_first(&cru->vdev.entity.pads[0]))
> +		ret = -EMLINK;
> +	mutex_unlock(&cru->mdev_lock);
> +
> +	return ret;
> +}
> +
> +static const struct media_device_ops rzg2l_cru_media_ops = {
> +	.link_notify = rzg2l_cru_csi2_link_notify,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Group async notifier
> + */
> +
> +static int rzg2l_cru_group_notify_complete(struct v4l2_async_notifier *notifier)
> +{
> +	struct rzg2l_cru_dev *cru = notifier_to_cru(notifier);
> +	struct media_entity *source, *sink;
> +	int ret;
> +
> +	ret = media_device_register(&cru->mdev);
> +	if (ret)
> +		return ret;

I'd move the v4l2_device_register() call here, as it's the V4L2
counterpart of the media device, and handling them together would be
best.

> +
> +	ret = rzg2l_cru_ip_subdev_register(cru);
> +	if (ret)
> +		return ret;
> +
> +	ret = v4l2_device_register_subdev_nodes(&cru->v4l2_dev);
> +	if (ret) {
> +		dev_err(cru->dev, "Failed to register subdev nodes\n");
> +		return ret;
> +	}
> +
> +	ret = rzg2l_cru_video_register(cru);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * CRU can be connected either to CSI2 or PARALLEL device
> +	 * For now we are only supporting CSI2
> +	 *
> +	 * Create media device link between CSI-2 <-> CRU IP
> +	 */
> +	source = &cru->csi.subdev->entity;
> +	sink = &cru->ip.subdev.entity;
> +	ret = media_create_pad_link(source, 1, sink, 0, 0);

Is there a reason not to create this link as ENABLED | IMMUTABLE ? I
think you could then drop rzg2l_cru_csi2_link_notify() and
rzg2l_cru_media_ops. The is_csi flag could also be dropped, or at least
several of the checks that test it.

> +	if (ret) {
> +		dev_err(cru->dev, "Error creating link from %s to %s\n",
> +			source->name, sink->name);
> +		return ret;
> +	}
> +
> +	/* Create media device link between CRU IP <-> CRU OUTPUT */
> +	source = &cru->ip.subdev.entity;
> +	sink = &cru->vdev.entity;
> +	ret = media_create_pad_link(source, 1, sink, 0, 0);

Same here.

> +	if (ret) {
> +		dev_err(cru->dev, "Error creating link from %s to %s\n",
> +			source->name, sink->name);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void rzg2l_cru_group_notify_unbind(struct v4l2_async_notifier *notifier,
> +					  struct v4l2_subdev *subdev,
> +					  struct v4l2_async_subdev *asd)
> +{
> +	struct rzg2l_cru_dev *cru = notifier_to_cru(notifier);
> +
> +	rzg2l_cru_ip_subdev_unregister(cru);
> +
> +	mutex_lock(&cru->mdev_lock);
> +
> +	if (cru->csi.asd == asd) {
> +		cru->csi.subdev = NULL;
> +		dev_dbg(cru->dev, "Unbind CSI-2 %s\n", subdev->name);
> +	}
> +
> +	mutex_unlock(&cru->mdev_lock);
> +
> +	media_device_unregister(&cru->mdev);
> +}
> +
> +static int rzg2l_cru_group_notify_bound(struct v4l2_async_notifier *notifier,
> +					struct v4l2_subdev *subdev,
> +					struct v4l2_async_subdev *asd)
> +{
> +	struct rzg2l_cru_dev *cru = notifier_to_cru(notifier);
> +
> +	mutex_lock(&cru->mdev_lock);
> +
> +	if (cru->csi.asd == asd) {
> +		cru->csi.subdev = subdev;
> +		dev_dbg(cru->dev, "Bound CSI-2 %s\n", subdev->name);
> +	}
> +
> +	mutex_unlock(&cru->mdev_lock);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_async_notifier_operations rzg2l_cru_async_ops = {
> +	.bound = rzg2l_cru_group_notify_bound,
> +	.unbind = rzg2l_cru_group_notify_unbind,
> +	.complete = rzg2l_cru_group_notify_complete,
> +};
> +
> +static int rzg2l_cru_mc_parse_of(struct rzg2l_cru_dev *cru)
> +{
> +	struct v4l2_fwnode_endpoint vep = {
> +		.bus_type = V4L2_MBUS_CSI2_DPHY,
> +	};
> +	struct fwnode_handle *ep, *fwnode;
> +	struct v4l2_async_subdev *asd;
> +	int ret;
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(cru->dev), 1, 0, 0);
> +	if (!ep)
> +		return 0;
> +
> +	fwnode = fwnode_graph_get_remote_endpoint(ep);
> +	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
> +	fwnode_handle_put(ep);
> +	if (ret) {
> +		dev_err(cru->dev, "Failed to parse %pOF\n", to_of_node(fwnode));
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (!of_device_is_available(to_of_node(fwnode))) {
> +		dev_dbg(cru->dev, "OF device %pOF disabled, ignoring\n",
> +			to_of_node(fwnode));
> +		ret = -ENOTCONN;
> +		goto out;
> +	}
> +
> +	asd = v4l2_async_nf_add_fwnode(&cru->notifier, fwnode,
> +				       struct v4l2_async_subdev);
> +	if (IS_ERR(asd)) {
> +		ret = PTR_ERR(asd);
> +		goto out;
> +	}
> +
> +	cru->csi.asd = asd;
> +
> +	dev_dbg(cru->dev, "Added OF device %pOF to slot %u\n",
> +		to_of_node(fwnode), vep.base.id);
> +out:
> +	fwnode_handle_put(fwnode);
> +
> +	return ret;
> +}
> +
> +static int rzg2l_cru_mc_parse_of_graph(struct rzg2l_cru_dev *cru)
> +{
> +	int ret;
> +
> +	v4l2_async_nf_init(&cru->notifier);
> +
> +	ret = rzg2l_cru_mc_parse_of(cru);
> +	if (ret)
> +		return ret;
> +
> +	cru->notifier.ops = &rzg2l_cru_async_ops;
> +
> +	if (list_empty(&cru->notifier.asd_list))
> +		return 0;
> +
> +	ret = v4l2_async_nf_register(&cru->v4l2_dev, &cru->notifier);
> +	if (ret < 0) {
> +		dev_err(cru->dev, "Notifier registration failed\n");
> +		v4l2_async_nf_cleanup(&cru->notifier);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_media_init(struct rzg2l_cru_dev *cru)
> +{
> +	struct media_device *mdev = NULL;
> +	const struct of_device_id *match;
> +	int ret;
> +
> +	cru->pad.flags = MEDIA_PAD_FL_SINK;
> +	ret = media_entity_pads_init(&cru->vdev.entity, 1, &cru->pad);
> +	if (ret)
> +		return ret;
> +
> +	mutex_init(&cru->mdev_lock);
> +	mdev = &cru->mdev;
> +	mdev->dev = cru->dev;
> +	mdev->ops = &rzg2l_cru_media_ops;
> +
> +	match = of_match_node(cru->dev->driver->of_match_table,
> +			      cru->dev->of_node);
> +
> +	strscpy(mdev->driver_name, KBUILD_MODNAME, sizeof(mdev->driver_name));
> +	strscpy(mdev->model, match->compatible, sizeof(mdev->model));
> +
> +	cru->v4l2_dev.mdev = &cru->mdev;
> +
> +	media_device_init(mdev);
> +
> +	ret = rzg2l_cru_mc_parse_of_graph(cru);
> +	if (ret) {
> +		mutex_lock(&cru->mdev_lock);
> +		cru->v4l2_dev.mdev = NULL;
> +		mutex_unlock(&cru->mdev_lock);
> +	}
> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_probe(struct platform_device *pdev)
> +{
> +	struct rzg2l_cru_dev *cru;
> +	int ret;
> +
> +	cru = devm_kzalloc(&pdev->dev, sizeof(*cru), GFP_KERNEL);
> +	if (!cru)
> +		return -ENOMEM;
> +
> +	cru->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(cru->base))
> +		return PTR_ERR(cru->base);
> +
> +	cru->presetn = devm_reset_control_get_shared(&pdev->dev, "presetn");
> +	if (IS_ERR(cru->presetn))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(cru->presetn),
> +				     "Failed to get cpg presetn\n");
> +
> +	cru->aresetn = devm_reset_control_get_exclusive(&pdev->dev, "aresetn");
> +	if (IS_ERR(cru->aresetn))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(cru->aresetn),
> +				     "Failed to get cpg aresetn\n");
> +
> +	cru->vclk = devm_clk_get(&pdev->dev, "video");
> +	if (IS_ERR(cru->vclk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(cru->vclk),
> +				     "Failed to get video clock\n");
> +
> +	cru->dev = &pdev->dev;
> +	cru->info = of_device_get_match_data(&pdev->dev);
> +
> +	cru->image_conv_irq = platform_get_irq(pdev, 0);
> +	if (cru->image_conv_irq < 0)
> +		return cru->image_conv_irq;
> +
> +	platform_set_drvdata(pdev, cru);
> +
> +	ret = rzg2l_cru_dma_register(cru);
> +	if (ret)
> +		return ret;
> +
> +	ret = rzg2l_cru_media_init(cru);
> +	if (ret)
> +		goto error_dma_unregister;
> +
> +	cru->num_buf = RZG2L_CRU_HW_BUFFER_DEFAULT;
> +	pm_suspend_ignore_children(&pdev->dev, true);
> +	pm_runtime_enable(&pdev->dev);

This should be done before rzg2l_cru_media_init(), as the function may
create the video nodes, and userspace may then use them immediately. I
would move those three lines just above rzg2l_cru_dma_register().

> +
> +	return 0;
> +
> +error_dma_unregister:
> +	rzg2l_cru_dma_unregister(cru);
> +
> +	return ret;
> +}
> +
> +static int rzg2l_cru_remove(struct platform_device *pdev)
> +{
> +	struct rzg2l_cru_dev *cru = platform_get_drvdata(pdev);
> +
> +	pm_runtime_disable(&pdev->dev);
> +
> +	v4l2_async_nf_unregister(&cru->notifier);
> +	v4l2_async_nf_cleanup(&cru->notifier);
> +
> +	rzg2l_cru_video_unregister(cru);
> +	media_device_cleanup(&cru->mdev);
> +	mutex_destroy(&cru->mdev_lock);
> +
> +	rzg2l_cru_dma_unregister(cru);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id rzg2l_cru_of_id_table[] = {
> +	{ .compatible = "renesas,rzg2l-cru", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, rzg2l_cru_of_id_table);
> +
> +static struct platform_driver rzg2l_cru_driver = {
> +	.driver = {
> +		.name = "rzg2l-cru",
> +		.of_match_table = rzg2l_cru_of_id_table,
> +	},
> +	.probe = rzg2l_cru_probe,
> +	.remove = rzg2l_cru_remove,
> +};
> +
> +module_platform_driver(rzg2l_cru_driver);
> +
> +MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
> +MODULE_DESCRIPTION("Renesas RZ/G2L CRU driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
> new file mode 100644
> index 000000000000..8aec94a4b03a
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
> @@ -0,0 +1,169 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Driver for Renesas RZ/G2L CRU
> + *
> + * Copyright (C) 2022 Renesas Electronics Corp.
> + */
> +
> +#ifndef __RZG2L_CRU__
> +#define __RZG2L_CRU__
> +
> +#include <linux/reset.h>
> +
> +#include <media/v4l2-async.h>
> +#include <media/v4l2-ctrls.h>

Can be dropped.

> +#include <media/v4l2-dev.h>
> +#include <media/v4l2-device.h>
> +#include <media/videobuf2-v4l2.h>
> +
> +/* Number of HW buffers */
> +#define RZG2L_CRU_HW_BUFFER_MAX		8
> +#define RZG2L_CRU_HW_BUFFER_DEFAULT	3
> +
> +/* Address alignment mask for HW buffers */
> +#define RZG2L_CRU_HW_BUFFER_MASK	0x1ff
> +
> +/* Maximum number of CSI2 virtual channels */
> +#define RZG2L_CRU_CSI2_VCHANNEL		4
> +
> +#define RZG2L_CRU_MIN_INPUT_WIDTH	320
> +#define RZG2L_CRU_MAX_INPUT_WIDTH	2800
> +#define RZG2L_CRU_MIN_INPUT_HEIGHT	240
> +#define RZG2L_CRU_MAX_INPUT_HEIGHT	4095
> +
> +/**
> + * enum rzg2l_cru_dma_state - DMA states
> + * @RZG2L_CRU_DMA_STOPPED:   No operation in progress
> + * @RZG2L_CRU_DMA_STARTING:  Capture starting up
> + * @RZG2L_CRU_DMA_RUNNING:   Operation in progress have buffers
> + * @RZG2L_CRU_DMA_STOPPING:  Stopping operation
> + */
> +enum rzg2l_cru_dma_state {
> +	RZG2L_CRU_DMA_STOPPED = 0,
> +	RZG2L_CRU_DMA_STARTING,
> +	RZG2L_CRU_DMA_RUNNING,
> +	RZG2L_CRU_DMA_STOPPING,
> +};
> +
> +struct rzg2l_cru_csi {
> +	struct v4l2_async_subdev *asd;
> +	struct v4l2_subdev *subdev;
> +	u32 channel;
> +};
> +
> +struct rzg2l_cru_ip {
> +	struct v4l2_subdev subdev;
> +	struct media_pad pads[2];
> +	struct v4l2_async_notifier notifier;
> +	struct v4l2_subdev *remote;
> +};
> +
> +/**
> + * struct rzg2l_cru_dev - Renesas CRU device structure
> + * @dev:		(OF) device
> + * @base:		device I/O register space remapped to virtual memory
> + * @info:		info about CRU instance
> + *
> + * @presetn:		CRU_PRESETN reset line
> + * @aresetn:		CRU_ARESETN reset line
> + *
> + * @vclk:		CRU Main clock
> + *
> + * @vdev:		V4L2 video device associated with CRU
> + * @v4l2_dev:		V4L2 device
> + * @ctrl_handler:	V4L2 control handler

The field doesn't exist.

> + * @num_buf:		Holds the current number of buffers enabled
> + * @notifier:		V4L2 asynchronous subdevs notifier
> + *
> + * @ip:			Image processing subdev info
> + * @csi:		CSI info
> + * @mdev:		media device
> + * @mdev_lock:		protects the count, notifier and csi members
> + * @pad:		media pad for the video device entity
> + *
> + * @lock:		protects @queue
> + * @queue:		vb2 buffers queue
> + * @scratch:		cpu address for scratch buffer
> + * @scratch_phys:	physical address of the scratch buffer
> + *
> + * @qlock:		protects @queue_buf, @buf_list, @sequence
> + *			@state
> + * @queue_buf:		Keeps track of buffers given to HW slot
> + * @buf_list:		list of queued buffers
> + * @sequence:		V4L2 buffers sequence number
> + * @state:		keeps track of operation state
> + *
> + * @is_csi:		flag to mark the CRU as using a CSI-2 subdevice
> + *
> + * @input_is_yuv:	flag to mark the input format of CRU
> + * @output_is_yuv:	flag to mark the output format of CRU

Those two fields are only used in rzg2l_cru_initialize_image_conv() and
in the rzg2l_cru_csi2_setup() function that it calls, I'd move them
there as local variables.

> + *
> + * @mbus_code:		media bus format code
> + * @format:		active V4L2 pixel format
> + *
> + * @compose:		active composing
> + */
> +struct rzg2l_cru_dev {
> +	struct device *dev;
> +	void __iomem *base;
> +	const struct rzg2l_cru_info *info;
> +
> +	struct reset_control *presetn;
> +	struct reset_control *aresetn;
> +
> +	struct clk *vclk;
> +
> +	int image_conv_irq;
> +
> +	struct video_device vdev;
> +	struct v4l2_device v4l2_dev;
> +	u8 num_buf;
> +
> +	struct v4l2_async_notifier notifier;
> +
> +	struct rzg2l_cru_ip ip;
> +	struct rzg2l_cru_csi csi;
> +	struct media_device mdev;
> +	struct mutex mdev_lock;
> +	struct media_pad pad;
> +
> +	struct mutex lock;
> +	struct vb2_queue queue;
> +	void *scratch;
> +	dma_addr_t scratch_phys;
> +
> +	spinlock_t qlock;
> +	struct vb2_v4l2_buffer *queue_buf[RZG2L_CRU_HW_BUFFER_MAX];
> +	struct list_head buf_list;
> +	unsigned int sequence;
> +	enum rzg2l_cru_dma_state state;
> +
> +	bool is_csi;
> +
> +	bool input_is_yuv;
> +	bool output_is_yuv;
> +
> +	u32 mbus_code;
> +	struct v4l2_pix_format format;
> +
> +	struct v4l2_rect compose;
> +};
> +
> +void rzg2l_cru_vclk_unprepare(struct rzg2l_cru_dev *cru);
> +int rzg2l_cru_vclk_prepare(struct rzg2l_cru_dev *cru);
> +
> +int rzg2l_cru_start_image_processing(struct rzg2l_cru_dev *cru);
> +void rzg2l_cru_stop_image_processing(struct rzg2l_cru_dev *cru);
> +
> +int rzg2l_cru_dma_register(struct rzg2l_cru_dev *cru);
> +void rzg2l_cru_dma_unregister(struct rzg2l_cru_dev *cru);
> +
> +int rzg2l_cru_video_register(struct rzg2l_cru_dev *cru);
> +void rzg2l_cru_video_unregister(struct rzg2l_cru_dev *cru);
> +
> +const struct v4l2_format_info *rzg2l_cru_format_from_pixel(u32 format);
> +
> +int rzg2l_cru_ip_subdev_register(struct rzg2l_cru_dev *cru);
> +void rzg2l_cru_ip_subdev_unregister(struct rzg2l_cru_dev *cru);
> +
> +#endif
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> new file mode 100644
> index 000000000000..0862bd918440
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> @@ -0,0 +1,283 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for Renesas RZ/G2L CRU
> + *
> + * Copyright (C) 2022 Renesas Electronics Corp.
> + */
> +
> +#include "rzg2l-cru.h"
> +
> +struct rzg2l_cru_ip_format {
> +	u32 code;
> +	unsigned int datatype;
> +	unsigned int bpp;
> +};
> +
> +static const struct rzg2l_cru_ip_format rzg2l_cru_ip_formats[] = {
> +	{ .code = MEDIA_BUS_FMT_UYVY8_1X16,	.datatype = 0x1e, .bpp = 16 },
> +};
> +
> +enum rzg2l_csi2_pads {
> +	RZG2L_CRU_IP_SINK = 0,
> +	RZG2L_CRU_IP_SOURCE,
> +};
> +
> +static const struct rzg2l_cru_ip_format
> +*rzg2l_cru_ip_code_to_fmt(unsigned int code)

static const struct rzg2l_cru_ip_format *
rzg2l_cru_ip_code_to_fmt(unsigned int code)

> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(rzg2l_cru_ip_formats); i++)
> +		if (rzg2l_cru_ip_formats[i].code == code)
> +			return &rzg2l_cru_ip_formats[i];
> +
> +	return NULL;
> +}
> +
> +static int rzg2l_cru_ip_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct rzg2l_cru_dev *cru;
> +	int s_stream_ret = 0;
> +	int ret;
> +
> +	cru = v4l2_get_subdevdata(sd);
> +
> +	if (!cru->is_csi)
> +		return -EINVAL;
> +
> +	if (!enable) {
> +		ret = v4l2_subdev_call(cru->ip.remote, video, s_stream, enable);
> +		if (ret)
> +			s_stream_ret = ret;
> +
> +		ret = v4l2_subdev_call(cru->ip.remote, video, post_streamoff);
> +		if (ret == -ENOIOCTLCMD)
> +			ret = 0;
> +		if (ret && !s_stream_ret)
> +			s_stream_ret = ret;
> +		rzg2l_cru_stop_image_processing(cru);
> +	} else {
> +		ret = v4l2_subdev_call(cru->ip.remote, video, pre_streamon, 0);
> +		if (ret == -ENOIOCTLCMD)
> +			ret = 0;
> +		if (ret)
> +			return ret;
> +
> +		ret = rzg2l_cru_start_image_processing(cru);
> +		if (ret) {
> +			v4l2_subdev_call(cru->ip.remote, video, post_streamoff);
> +			return ret;
> +		}
> +
> +		rzg2l_cru_vclk_unprepare(cru);
> +
> +		ret = v4l2_subdev_call(cru->ip.remote, video, s_stream, enable);
> +		if (ret == -ENOIOCTLCMD)
> +			ret = 0;
> +		if (!ret) {
> +			ret = rzg2l_cru_vclk_prepare(cru);
> +			if (!ret)
> +				return 0;
> +		} else {
> +			/* enable back vclk so that release() disables it */
> +			if (rzg2l_cru_vclk_prepare(cru))
> +				dev_err(cru->dev, "Failed to enable vclk\n");
> +		}
> +
> +		s_stream_ret = ret;
> +
> +		v4l2_subdev_call(cru->ip.remote, video, post_streamoff);
> +		rzg2l_cru_stop_image_processing(cru);
> +	}
> +
> +	return s_stream_ret;
> +}
> +
> +static int rzg2l_cru_ip_set_format(struct v4l2_subdev *sd,
> +				   struct v4l2_subdev_state *state,
> +				   struct v4l2_subdev_format *fmt)
> +{
> +	struct v4l2_mbus_framefmt *format;
> +
> +	if (fmt->pad != RZG2L_CRU_IP_SINK && fmt->pad != RZG2L_CRU_IP_SOURCE)
> +		return -EINVAL;
> +
> +	format = v4l2_subdev_get_pad_format(sd, state, fmt->pad);
> +
> +	if (!rzg2l_cru_ip_code_to_fmt(fmt->format.code))
> +		format->code = rzg2l_cru_ip_formats[0].code;
> +	else
> +		format->code = fmt->format.code;
> +
> +	format->field = V4L2_FIELD_NONE;
> +	format->colorspace = fmt->format.colorspace;
> +	format->xfer_func = fmt->format.xfer_func;
> +	format->ycbcr_enc = fmt->format.ycbcr_enc;
> +	format->quantization = fmt->format.quantization;
> +	format->width = clamp_t(u32, fmt->format.width,
> +				RZG2L_CRU_MIN_INPUT_WIDTH, RZG2L_CRU_MAX_INPUT_WIDTH);
> +	format->height = clamp_t(u32, fmt->format.height,
> +				 RZG2L_CRU_MIN_INPUT_HEIGHT, RZG2L_CRU_MAX_INPUT_HEIGHT);
> +
> +	fmt->format = *format;

Missing format propagation. At least the width and height must be
propagated as, as far as I understand the CRU can't scale. The
colorspace and xfer_func values must be propagated too. As you don't
handle ycbcr_enc and quantization in the driver (is it configurable in
the hardware ?), they should be propagated too.

Furthermore, when setting the format on the source pad, those fields
must be be overwritten as they must always be identical to the sink pad.

Please run v4l2-compliance for the subdev too.

> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_ip_enum_mbus_code(struct v4l2_subdev *sd,
> +				       struct v4l2_subdev_state *state,
> +				       struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->index >= ARRAY_SIZE(rzg2l_cru_ip_formats))
> +		return -EINVAL;
> +
> +	code->code = rzg2l_cru_ip_formats[code->index].code;
> +	return 0;
> +}
> +
> +static int rzg2l_cru_ip_enum_frame_size(struct v4l2_subdev *sd,
> +					struct v4l2_subdev_state *state,
> +					struct v4l2_subdev_frame_size_enum *fse)
> +{
> +	if (fse->index != 0)
> +		return -EINVAL;

You should verify here that the format is valid, and return -EINVAL
otherwise.

> +
> +	fse->min_width = RZG2L_CRU_MIN_INPUT_WIDTH;
> +	fse->min_height = RZG2L_CRU_MIN_INPUT_HEIGHT;
> +	fse->max_width = RZG2L_CRU_MAX_INPUT_WIDTH;
> +	fse->max_height = RZG2L_CRU_MAX_INPUT_HEIGHT;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_ip_init_config(struct v4l2_subdev *sd,
> +				    struct v4l2_subdev_state *sd_state)
> +{
> +	struct v4l2_subdev_format fmt = { .pad = RZG2L_CRU_IP_SINK, };
> +	int ret;
> +
> +	fmt.format.width = RZG2L_CRU_MIN_INPUT_WIDTH;
> +	fmt.format.height = RZG2L_CRU_MIN_INPUT_HEIGHT;
> +	fmt.format.field = V4L2_FIELD_NONE;
> +	fmt.format.code = MEDIA_BUS_FMT_UYVY8_1X16;
> +	fmt.format.colorspace = V4L2_COLORSPACE_SRGB;
> +	fmt.format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> +	fmt.format.quantization = V4L2_QUANTIZATION_DEFAULT;
> +	fmt.format.xfer_func = V4L2_XFER_FUNC_DEFAULT;
> +
> +	ret = rzg2l_cru_ip_set_format(sd, sd_state, &fmt);
> +	if (ret)
> +		return ret;
> +
> +	fmt.pad = RZG2L_CRU_IP_SOURCE;
> +	return rzg2l_cru_ip_set_format(sd, sd_state, &fmt);

Doing it on the sink pad should be enough if you implement format
propagation.

> +}
> +
> +static int rzg2l_cru_ip_link_setup(struct media_entity *entity,
> +				   const struct media_pad *local,
> +				   const struct media_pad *remote, u32 flags)
> +{
> +	struct v4l2_subdev *remote_source;
> +	struct v4l2_subdev *ip_sd;
> +	struct rzg2l_cru_dev *cru;
> +
> +	ip_sd = media_entity_to_v4l2_subdev(entity);
> +	cru = v4l2_get_subdevdata(ip_sd);
> +	/* We are only interested in remote link */
> +	if ((flags & MEDIA_LNK_FL_ENABLED) && remote) {
> +		if (media_pad_remote_pad_first(remote))
> +			return -EMLINK;
> +
> +		remote_source = media_entity_to_v4l2_subdev(remote->entity);
> +
> +		if (cru->csi.subdev && cru->csi.subdev == remote_source) {
> +			/* Default to VC0 for now */
> +			cru->csi.channel = 0;
> +			cru->is_csi = true;
> +			cru->ip.remote = remote_source;
> +		}
> +	} else if (!flags) {
> +		remote_source = media_entity_to_v4l2_subdev(remote->entity);
> +		if (cru->csi.subdev == remote_source) {
> +			cru->is_csi = false;
> +			cru->ip.remote = NULL;
> +		}
> +	}

Let's make the link to the source immutable and drop all this.

> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_video_ops rzg2l_cru_ip_video_ops = {
> +	.s_stream = rzg2l_cru_ip_s_stream,
> +};
> +
> +static const struct v4l2_subdev_core_ops rzg2l_cru_ip_core_ops = {
> +	.log_status = v4l2_ctrl_subdev_log_status,

The subdev has no control, you can drop this.

> +};
> +
> +static const struct v4l2_subdev_pad_ops rzg2l_cru_ip_pad_ops = {
> +	.enum_mbus_code = rzg2l_cru_ip_enum_mbus_code,
> +	.enum_frame_size = rzg2l_cru_ip_enum_frame_size,
> +	.init_cfg = rzg2l_cru_ip_init_config,
> +	.get_fmt = v4l2_subdev_get_fmt,
> +	.set_fmt = rzg2l_cru_ip_set_format,
> +};
> +
> +static const struct v4l2_subdev_ops rzg2l_cru_ip_subdev_ops = {
> +	.core = &rzg2l_cru_ip_core_ops,
> +	.video = &rzg2l_cru_ip_video_ops,
> +	.pad = &rzg2l_cru_ip_pad_ops,
> +};
> +
> +static const struct media_entity_operations rzg2l_cru_ip_entity_ops = {
> +	.link_setup = rzg2l_cru_ip_link_setup,
> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
> +int rzg2l_cru_ip_subdev_register(struct rzg2l_cru_dev *cru)
> +{
> +	struct rzg2l_cru_ip *ip = &cru->ip;
> +	int ret;
> +
> +	ip->subdev.dev = cru->dev;
> +	v4l2_subdev_init(&ip->subdev, &rzg2l_cru_ip_subdev_ops);
> +	v4l2_set_subdevdata(&ip->subdev, cru);
> +	snprintf(ip->subdev.name, sizeof(ip->subdev.name),
> +		 "cru-ip-%s", dev_name(cru->dev));
> +	ip->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> +	ip->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
> +	ip->subdev.entity.ops = &rzg2l_cru_ip_entity_ops;
> +
> +	ip->pads[0].flags = MEDIA_PAD_FL_SINK;
> +	ip->pads[1].flags = MEDIA_PAD_FL_SOURCE;
> +
> +	ret = media_entity_pads_init(&ip->subdev.entity, 2, ip->pads);
> +	if (ret)
> +		return ret;
> +
> +	ret = v4l2_subdev_init_finalize(&ip->subdev);
> +	if (ret < 0)
> +		goto entity_cleanup;
> +
> +	ret = v4l2_device_register_subdev(&cru->v4l2_dev, &ip->subdev);
> +	if (ret < 0)
> +		goto error_subdev;
> +
> +	return 0;
> +error_subdev:
> +	v4l2_subdev_cleanup(&ip->subdev);
> +entity_cleanup:
> +	media_entity_cleanup(&ip->subdev.entity);
> +
> +	return ret;
> +}
> +
> +void rzg2l_cru_ip_subdev_unregister(struct rzg2l_cru_dev *cru)
> +{
> +	struct rzg2l_cru_ip *ip = &cru->ip;
> +
> +	media_entity_cleanup(&ip->subdev.entity);
> +	v4l2_subdev_cleanup(&ip->subdev);
> +	v4l2_device_unregister_subdev(&ip->subdev);
> +}
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> new file mode 100644
> index 000000000000..9bf1446b5418
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> @@ -0,0 +1,1086 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Driver for Renesas RZ/G2L CRU
> + *
> + * Copyright (C) 2022 Renesas Electronics Corp.
> + *
> + * Based on Renesas R-Car VIN
> + * Copyright (C) 2016 Renesas Electronics Corp.
> + * Copyright (C) 2011-2013 Renesas Solutions Corp.
> + * Copyright (C) 2013 Cogent Embedded, Inc., <source@cogentembedded.com>
> + * Copyright (C) 2008 Magnus Damm
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <media/v4l2-event.h>

Can be dropped.

> +#include <media/v4l2-ioctl.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include "rzg2l-cru.h"
> +
> +/* HW CRU Registers Definition */
> +
> +/* CRU Control Register */
> +#define CRUnCTRL			0x0
> +#define CRUnCTRL_VINSEL(x)		((x) << 0)
> +
> +/* CRU Interrupt Enable Register */
> +#define CRUnIE				0x4
> +#define CRUnIE_EFE			BIT(17)
> +
> +/* CRU Interrupt Status Register */
> +#define CRUnINTS			0x8
> +#define CRUnINTS_SFS			BIT(16)
> +
> +/* CRU Reset Register */
> +#define CRUnRST				0xc
> +#define CRUnRST_VRESETN			BIT(0)
> +
> +/* Memory Bank Base Address (Lower) Register for CRU Image Data */
> +#define AMnMBxADDRL(x)			(0x100 + ((x) * 8))
> +
> +/* Memory Bank Base Address (Higher) Register for CRU Image Data */
> +#define AMnMBxADDRH(x)			(0x104 + ((x) * 8))
> +
> +/* Memory Bank Enable Register for CRU Image Data */
> +#define AMnMBVALID			0x148
> +#define AMnMBVALID_MBVALID(x)		GENMASK(x, 0)
> +
> +/* Memory Bank Status Register for CRU Image Data */
> +#define AMnMBS				0x14c
> +#define AMnMBS_MBSTS			0x7
> +
> +/* AXI Master FIFO Pointer Register for CRU Image Data */
> +#define AMnFIFOPNTR			0x168
> +#define AMnFIFOPNTR_FIFOWPNTR		GENMASK(7, 0)
> +#define AMnFIFOPNTR_FIFORPNTR_Y		GENMASK(23, 16)
> +
> +/* AXI Master Transfer Stop Register for CRU Image Data */
> +#define AMnAXISTP			0x174
> +#define AMnAXISTP_AXI_STOP		BIT(0)
> +
> +/* AXI Master Transfer Stop Status Register for CRU Image Data */
> +#define AMnAXISTPACK			0x178
> +#define AMnAXISTPACK_AXI_STOP_ACK	BIT(0)
> +
> +/* CRU Image Processing Enable Register */
> +#define ICnEN				0x200
> +#define ICnEN_ICEN			BIT(0)
> +
> +/* CRU Image Processing Main Control Register */
> +#define ICnMC				0x208
> +#define ICnMC_CSCTHR			BIT(5)
> +#define ICnMC_INF_YUV8_422		(0x1e << 16)
> +#define ICnMC_INF_USER			(0x30 << 16)
> +#define ICnMC_VCSEL(x)			((x) << 22)
> +#define ICnMC_INF_MASK			GENMASK(21, 16)
> +
> +/* CRU Module Status Register */
> +#define ICnMS				0x254
> +#define ICnMS_IA			BIT(2)
> +
> +/* CRU Data Output Mode Register */
> +#define ICnDMR				0x26c
> +#define ICnDMR_YCMODE_UYVY		(1 << 4)
> +
> +#define RZG2L_TIMEOUT_MS		100
> +#define RZG2L_RETRIES			10
> +
> +#define RZG2L_CRU_DEFAULT_FORMAT	V4L2_PIX_FMT_UYVY
> +#define RZG2L_CRU_DEFAULT_WIDTH		RZG2L_CRU_MIN_INPUT_WIDTH
> +#define RZG2L_CRU_DEFAULT_HEIGHT	RZG2L_CRU_MIN_INPUT_HEIGHT
> +#define RZG2L_CRU_DEFAULT_FIELD		V4L2_FIELD_NONE
> +#define RZG2L_CRU_DEFAULT_COLORSPACE	V4L2_COLORSPACE_SRGB
> +
> +struct rzg2l_cru_buffer {
> +	struct vb2_v4l2_buffer vb;
> +	struct list_head list;
> +};
> +
> +#define to_buf_list(vb2_buffer) \
> +	(&container_of(vb2_buffer, struct rzg2l_cru_buffer, vb)->list)
> +
> +/* -----------------------------------------------------------------------------
> + * DMA operations
> + */
> +static void rzg2l_cru_write(struct rzg2l_cru_dev *cru, u32 offset, u32 value)
> +{
> +	iowrite32(value, cru->base + offset);
> +}
> +
> +static u32 rzg2l_cru_read(struct rzg2l_cru_dev *cru, u32 offset)
> +{
> +	return ioread32(cru->base + offset);
> +}
> +
> +/* Need to hold qlock before calling */
> +static void return_unused_buffers(struct rzg2l_cru_dev *cru,
> +				  enum vb2_buffer_state state)
> +{
> +	struct rzg2l_cru_buffer *buf, *node;
> +	unsigned long flags;
> +	unsigned int i;
> +
> +	spin_lock_irqsave(&cru->qlock, flags);
> +	for (i = 0; i < cru->num_buf; i++) {
> +		if (cru->queue_buf[i]) {
> +			vb2_buffer_done(&cru->queue_buf[i]->vb2_buf,
> +					state);
> +			cru->queue_buf[i] = NULL;
> +		}
> +	}
> +
> +	list_for_each_entry_safe(buf, node, &cru->buf_list, list) {
> +		vb2_buffer_done(&buf->vb.vb2_buf, state);
> +		list_del(&buf->list);
> +	}
> +	spin_unlock_irqrestore(&cru->qlock, flags);
> +}
> +
> +static int rzg2l_cru_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
> +				 unsigned int *nplanes, unsigned int sizes[],
> +				 struct device *alloc_devs[])
> +{
> +	struct rzg2l_cru_dev *cru = vb2_get_drv_priv(vq);
> +
> +	/* Make sure the image size is large enough. */
> +	if (*nplanes)
> +		return sizes[0] < cru->format.sizeimage ? -EINVAL : 0;
> +
> +	*nplanes = 1;
> +	sizes[0] = cru->format.sizeimage;
> +
> +	return 0;
> +};
> +
> +static int rzg2l_cru_buffer_prepare(struct vb2_buffer *vb)
> +{
> +	struct rzg2l_cru_dev *cru = vb2_get_drv_priv(vb->vb2_queue);
> +	unsigned long size = cru->format.sizeimage;
> +
> +	if (vb2_plane_size(vb, 0) < size) {
> +		dev_err(cru->dev, "buffer too small (%lu < %lu)\n",
> +			vb2_plane_size(vb, 0), size);
> +		return -EINVAL;
> +	}
> +
> +	vb2_set_plane_payload(vb, 0, size);
> +
> +	return 0;
> +}
> +
> +static void rzg2l_cru_buffer_queue(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct rzg2l_cru_dev *cru = vb2_get_drv_priv(vb->vb2_queue);
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&cru->qlock, flags);
> +
> +	list_add_tail(to_buf_list(vbuf), &cru->buf_list);
> +
> +	spin_unlock_irqrestore(&cru->qlock, flags);
> +}
> +
> +static int rzg2l_cru_mc_validate_format(struct rzg2l_cru_dev *cru,
> +					struct v4l2_subdev *sd,
> +					struct media_pad *pad)
> +{
> +	struct v4l2_subdev_format fmt = {
> +		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> +	};
> +
> +	fmt.pad = pad->index;
> +	if (v4l2_subdev_call_state_active(sd, pad, get_fmt, &fmt))
> +		return -EPIPE;
> +
> +	if (cru->is_csi) {
> +		switch (fmt.format.code) {
> +		case MEDIA_BUS_FMT_UYVY8_1X16:
> +			break;
> +		default:
> +			return -EPIPE;
> +		}
> +	}
> +	cru->mbus_code = fmt.format.code;
> +
> +	switch (fmt.format.field) {
> +	case V4L2_FIELD_TOP:
> +	case V4L2_FIELD_BOTTOM:
> +	case V4L2_FIELD_NONE:
> +	case V4L2_FIELD_INTERLACED_TB:
> +	case V4L2_FIELD_INTERLACED_BT:
> +	case V4L2_FIELD_INTERLACED:
> +	case V4L2_FIELD_SEQ_TB:
> +	case V4L2_FIELD_SEQ_BT:
> +		break;
> +	default:
> +		return -EPIPE;
> +	}
> +
> +	if (fmt.format.width != cru->format.width ||
> +	    fmt.format.height != cru->format.height ||
> +	    fmt.format.code != cru->mbus_code)
> +		return -EPIPE;
> +
> +	return 0;
> +}
> +
> +static void rzg2l_cru_set_slot_addr(struct rzg2l_cru_dev *cru,
> +				    int slot, dma_addr_t addr)
> +{
> +	const struct v4l2_format_info *fmt;
> +	int offsetx, offsety;
> +	dma_addr_t offset;
> +
> +	fmt = rzg2l_cru_format_from_pixel(cru->format.pixelformat);
> +
> +	/*
> +	 * There is no HW support for composition do the best we can
> +	 * by modifying the buffer offset
> +	 */
> +	offsetx = cru->compose.left * fmt->bpp[0];
> +	offsety = cru->compose.top * cru->format.bytesperline;
> +	offset = addr + offsetx + offsety;
> +
> +	/*
> +	 * The address needs to be 512 bytes aligned. Driver should never accept
> +	 * settings that do not satisfy this in the first place...
> +	 */
> +	if (WARN_ON((offsetx | offsety | offset) & RZG2L_CRU_HW_BUFFER_MASK))
> +		return;
> +
> +	/* Currently, we just use the buffer in 32 bits address */
> +	rzg2l_cru_write(cru, AMnMBxADDRL(slot), offset);
> +	rzg2l_cru_write(cru, AMnMBxADDRH(slot), 0);
> +}
> +
> +/*
> + * Moves a buffer from the queue to the HW slot. If no buffer is
> + * available use the scratch buffer. The scratch buffer is never
> + * returned to userspace, its only function is to enable the capture
> + * loop to keep running.
> + */
> +static void rzg2l_cru_fill_hw_slot(struct rzg2l_cru_dev *cru, int slot)
> +{
> +	struct vb2_v4l2_buffer *vbuf;
> +	struct rzg2l_cru_buffer *buf;
> +	dma_addr_t phys_addr;
> +
> +	/* A already populated slot shall never be overwritten. */
> +	if (WARN_ON(cru->queue_buf[slot]))
> +		return;
> +
> +	dev_dbg(cru->dev, "Filling HW slot: %d\n", slot);
> +
> +	if (list_empty(&cru->buf_list)) {
> +		cru->queue_buf[slot] = NULL;
> +		phys_addr = cru->scratch_phys;
> +	} else {
> +		/* Keep track of buffer we give to HW */
> +		buf = list_entry(cru->buf_list.next,
> +				 struct rzg2l_cru_buffer, list);
> +		vbuf = &buf->vb;
> +		list_del_init(to_buf_list(vbuf));
> +		cru->queue_buf[slot] = vbuf;
> +
> +		/* Setup DMA */
> +		phys_addr = vb2_dma_contig_plane_dma_addr(&vbuf->vb2_buf, 0);
> +	}
> +
> +	rzg2l_cru_set_slot_addr(cru, slot, phys_addr);
> +}
> +
> +static void rzg2l_cru_initialize_axi(struct rzg2l_cru_dev *cru)
> +{
> +	unsigned int slot;
> +
> +	/*
> +	 * Set image data memory banks.
> +	 * Currently, we will use maximum address.
> +	 */
> +	rzg2l_cru_write(cru, AMnMBVALID, AMnMBVALID_MBVALID(cru->num_buf - 1));
> +
> +	for (slot = 0; slot < cru->num_buf; slot++)
> +		rzg2l_cru_fill_hw_slot(cru, slot);
> +}
> +
> +static void rzg2l_cru_csi2_setup(struct rzg2l_cru_dev *cru)
> +{
> +	u32 icnmc;
> +
> +	switch (cru->mbus_code) {

Let's minimize the amount of state stored in the rzg2l_cru_dev
structure, you can drop the mbus_code field and retrieve the mbus code
from the subdev's source pad here.

> +	case MEDIA_BUS_FMT_UYVY8_1X16:
> +		icnmc = ICnMC_INF_YUV8_422;
> +		cru->input_is_yuv = true;
> +		break;
> +	default:
> +		cru->input_is_yuv = false;
> +		icnmc = ICnMC_INF_USER;
> +		break;
> +	}
> +
> +	icnmc |= (rzg2l_cru_read(cru, ICnMC) & ~ICnMC_INF_MASK);
> +
> +	/* Set virtual channel CSI2 */
> +	icnmc |= ICnMC_VCSEL(cru->csi.channel);
> +
> +	rzg2l_cru_write(cru, ICnMC, icnmc);
> +}
> +
> +static int rzg2l_cru_initialize_image_conv(struct rzg2l_cru_dev *cru)
> +{
> +	u32 icndmr;
> +
> +	if (cru->is_csi)
> +		rzg2l_cru_csi2_setup(cru);
> +
> +	/* Output format */
> +	switch (cru->format.pixelformat) {
> +	case V4L2_PIX_FMT_UYVY:
> +		icndmr = ICnDMR_YCMODE_UYVY;
> +		cru->output_is_yuv = true;
> +		break;
> +	default:
> +		dev_err(cru->dev, "Invalid pixelformat (0x%x)\n",
> +			cru->format.pixelformat);
> +		return -EINVAL;
> +	}
> +
> +	/* If input and output use same colorspace, do bypass mode */
> +	if (cru->output_is_yuv == cru->input_is_yuv)
> +		rzg2l_cru_write(cru, ICnMC,
> +				rzg2l_cru_read(cru, ICnMC) | ICnMC_CSCTHR);
> +	else
> +		rzg2l_cru_write(cru, ICnMC,
> +				rzg2l_cru_read(cru, ICnMC) & (~ICnMC_CSCTHR));
> +
> +	/* Set output data format */
> +	rzg2l_cru_write(cru, ICnDMR, icndmr);
> +
> +	return 0;
> +}
> +
> +void rzg2l_cru_stop_image_processing(struct rzg2l_cru_dev *cru)
> +{
> +	u32 amnfifopntr, amnfifopntr_w, amnfifopntr_r_y;
> +	unsigned int retries = 0;
> +	unsigned long flags;
> +	u32 icnms;
> +
> +	spin_lock_irqsave(&cru->qlock, flags);
> +
> +	/* Disable and clear the interrupt */
> +	rzg2l_cru_write(cru, CRUnIE, 0);
> +	rzg2l_cru_write(cru, CRUnINTS, 0x001F0F0F);
> +
> +	/* Stop the operation of image conversion */
> +	rzg2l_cru_write(cru, ICnEN, 0);
> +
> +	/* Wait for streaming to stop */
> +	while ((rzg2l_cru_read(cru, ICnMS) & ICnMS_IA) && retries++ < RZG2L_RETRIES) {
> +		spin_unlock_irqrestore(&cru->qlock, flags);
> +		msleep(RZG2L_TIMEOUT_MS);
> +		spin_lock_irqsave(&cru->qlock, flags);
> +	}
> +
> +	icnms = rzg2l_cru_read(cru, ICnMS) & ICnMS_IA;
> +	if (icnms)
> +		dev_err(cru->dev, "Failed stop HW, something is seriously broken\n");
> +
> +	cru->state = RZG2L_CRU_DMA_STOPPED;
> +
> +	/* Wait until the FIFO becomes empty */
> +	for (retries = 5; retries > 0; retries--) {
> +		amnfifopntr = rzg2l_cru_read(cru, AMnFIFOPNTR);
> +
> +		amnfifopntr_w = amnfifopntr & AMnFIFOPNTR_FIFOWPNTR;
> +		amnfifopntr_r_y =
> +			(amnfifopntr & AMnFIFOPNTR_FIFORPNTR_Y) >> 16;
> +		if (amnfifopntr_w == amnfifopntr_r_y)
> +			break;
> +
> +		usleep_range(10, 20);
> +	}
> +
> +	/* Notify that FIFO is not empty here */
> +	if (!retries)
> +		dev_err(cru->dev, "Failed to empty FIFO\n");
> +
> +	/* Stop AXI bus */
> +	rzg2l_cru_write(cru, AMnAXISTP, AMnAXISTP_AXI_STOP);
> +
> +	/* Wait until the AXI bus stop */
> +	for (retries = 5; retries > 0; retries--) {
> +		if (rzg2l_cru_read(cru, AMnAXISTPACK) &
> +			AMnAXISTPACK_AXI_STOP_ACK)
> +			break;
> +
> +		usleep_range(10, 20);
> +	};
> +
> +	/* Notify that AXI bus can not stop here */
> +	if (!retries)
> +		dev_err(cru->dev, "Failed to stop AXI bus\n");
> +
> +	/* Cancel the AXI bus stop request */
> +	rzg2l_cru_write(cru, AMnAXISTP, 0);
> +
> +	/* Reset the CRU (AXI-master) */
> +	reset_control_assert(cru->aresetn);
> +
> +	/* Resets the image processing module */
> +	rzg2l_cru_write(cru, CRUnRST, 0);
> +
> +	spin_unlock_irqrestore(&cru->qlock, flags);
> +}
> +
> +int rzg2l_cru_start_image_processing(struct rzg2l_cru_dev *cru)
> +{
> +	unsigned long flags;
> +	int ret;
> +
> +	spin_lock_irqsave(&cru->qlock, flags);
> +
> +	/* Initialize image convert */
> +	ret = rzg2l_cru_initialize_image_conv(cru);
> +	if (ret) {
> +		spin_unlock_irqrestore(&cru->qlock, flags);
> +		return ret;
> +	}
> +
> +	/* Select a video input */
> +	if (cru->is_csi)
> +		rzg2l_cru_write(cru, CRUnCTRL, CRUnCTRL_VINSEL(0));
> +
> +	/* Cancel the software reset for image processing block */
> +	rzg2l_cru_write(cru, CRUnRST, CRUnRST_VRESETN);
> +
> +	/* Disable and clear the interrupt before using */
> +	rzg2l_cru_write(cru, CRUnIE, 0);
> +	rzg2l_cru_write(cru, CRUnINTS, 0x001f000f);
> +
> +	/* Initialize the AXI master */
> +	rzg2l_cru_initialize_axi(cru);
> +
> +	/* Enable interrupt */
> +	rzg2l_cru_write(cru, CRUnIE, CRUnIE_EFE);
> +
> +	/* Enable image processing reception */
> +	rzg2l_cru_write(cru, ICnEN, ICnEN_ICEN);
> +
> +	spin_unlock_irqrestore(&cru->qlock, flags);
> +
> +	return 0;
> +}
> +
> +void rzg2l_cru_vclk_unprepare(struct rzg2l_cru_dev *cru)
> +{
> +	clk_disable_unprepare(cru->vclk);
> +}
> +
> +int rzg2l_cru_vclk_prepare(struct rzg2l_cru_dev *cru)
> +{
> +	return clk_prepare_enable(cru->vclk);
> +}
> +
> +static int rzg2l_cru_set_stream(struct rzg2l_cru_dev *cru, int on)
> +{
> +	struct media_pipeline *pipe;
> +	struct v4l2_subdev *sd;
> +	struct media_pad *pad;
> +	int ret;
> +
> +	pad = media_pad_remote_pad_first(&cru->pad);
> +	if (!pad)
> +		return -EPIPE;
> +
> +	sd = media_entity_to_v4l2_subdev(pad->entity);
> +
> +	if (!on) {
> +		int stream_off_ret = 0;
> +
> +		ret = v4l2_subdev_call(sd, video, s_stream, 0);
> +		if (ret)
> +			stream_off_ret = ret;
> +
> +		ret = v4l2_subdev_call(sd, video, post_streamoff);
> +		if (ret == -ENOIOCTLCMD)
> +			ret = 0;
> +		if (ret && !stream_off_ret)
> +			stream_off_ret = ret;
> +
> +		media_pipeline_stop(&cru->vdev.entity);
> +
> +		return stream_off_ret;
> +	}
> +
> +	ret = rzg2l_cru_mc_validate_format(cru, sd, pad);
> +	if (ret)
> +		return ret;
> +
> +	pipe = sd->entity.pipe ? sd->entity.pipe : &cru->vdev.pipe;
> +	ret = media_pipeline_start(&cru->vdev.entity, pipe);
> +	if (ret)
> +		return ret;
> +
> +	ret = v4l2_subdev_call(sd, video, pre_streamon, 0);
> +	if (ret == -ENOIOCTLCMD)
> +		ret = 0;
> +	if (ret)
> +		goto pipe_line_stop;
> +
> +	ret = v4l2_subdev_call(sd, video, s_stream, 1);
> +	if (ret == -ENOIOCTLCMD)
> +		ret = 0;
> +	if (ret)
> +		goto err_s_stream;
> +
> +	return 0;
> +
> +err_s_stream:
> +	v4l2_subdev_call(sd, video, post_streamoff);
> +
> +pipe_line_stop:
> +	media_pipeline_stop(&cru->vdev.entity);
> +
> +	return ret;
> +}
> +
> +static void rzg2l_cru_stop_streaming(struct rzg2l_cru_dev *cru)
> +{
> +	cru->state = RZG2L_CRU_DMA_STOPPING;
> +
> +	rzg2l_cru_set_stream(cru, 0);
> +}
> +
> +static irqreturn_t rzg2l_cru_irq(int irq, void *data)
> +{
> +	struct rzg2l_cru_dev *cru = data;
> +	unsigned int handled = 0;
> +	unsigned long flags;
> +	u32 irq_status;
> +	u32 amnmbs;
> +	int slot;
> +
> +	spin_lock_irqsave(&cru->qlock, flags);
> +
> +	irq_status = rzg2l_cru_read(cru, CRUnINTS);
> +	if (!irq_status)
> +		goto done;
> +
> +	handled = 1;
> +
> +	rzg2l_cru_write(cru, CRUnINTS, rzg2l_cru_read(cru, CRUnINTS));
> +
> +	/* Nothing to do if capture status is 'RZG2L_CRU_DMA_STOPPED' */
> +	if (cru->state == RZG2L_CRU_DMA_STOPPED) {
> +		dev_dbg(cru->dev, "IRQ while state stopped\n");
> +		goto done;
> +	}
> +
> +	/* Increase stop retries if capture status is 'RZG2L_CRU_DMA_STOPPING' */
> +	if (cru->state == RZG2L_CRU_DMA_STOPPING) {
> +		if (irq_status & CRUnINTS_SFS)
> +			dev_dbg(cru->dev, "IRQ while state stopping\n");
> +		goto done;
> +	}
> +
> +	/* Prepare for capture and update state */
> +	amnmbs = rzg2l_cru_read(cru, AMnMBS);
> +	slot = amnmbs & AMnMBS_MBSTS;
> +
> +	/*
> +	 * AMnMBS.MBSTS indicates the destination of Memory Bank (MB).
> +	 * Recalculate to get the current transfer complete MB.
> +	 */
> +	if (slot == 0)
> +		slot = cru->num_buf - 1;
> +	else
> +		slot--;
> +
> +	/*
> +	 * To hand buffers back in a known order to userspace start
> +	 * to capture first from slot 0.
> +	 */
> +	if (cru->state == RZG2L_CRU_DMA_STARTING) {
> +		if (slot != 0) {
> +			dev_dbg(cru->dev, "Starting sync slot: %d\n", slot);
> +			goto done;
> +		}
> +
> +		dev_dbg(cru->dev, "Capture start synced!\n");
> +		cru->state = RZG2L_CRU_DMA_RUNNING;
> +	}
> +
> +	/* Capture frame */
> +	if (cru->queue_buf[slot]) {
> +		cru->queue_buf[slot]->field = cru->format.field;
> +		cru->queue_buf[slot]->sequence = cru->sequence;
> +		cru->queue_buf[slot]->vb2_buf.timestamp = ktime_get_ns();
> +		vb2_buffer_done(&cru->queue_buf[slot]->vb2_buf,
> +				VB2_BUF_STATE_DONE);
> +		cru->queue_buf[slot] = NULL;
> +	} else {
> +		/* Scratch buffer was used, dropping frame. */
> +		dev_dbg(cru->dev, "Dropping frame %u\n", cru->sequence);
> +	}
> +
> +	cru->sequence++;
> +
> +	/* Prepare for next frame */
> +	rzg2l_cru_fill_hw_slot(cru, slot);
> +
> +done:
> +	spin_unlock_irqrestore(&cru->qlock, flags);
> +
> +	return IRQ_RETVAL(handled);
> +}
> +
> +static int rzg2l_cru_start_streaming_vq(struct vb2_queue *vq, unsigned int count)
> +{
> +	struct rzg2l_cru_dev *cru = vb2_get_drv_priv(vq);
> +	int ret;
> +
> +	/* Release reset state */
> +	ret = reset_control_deassert(cru->aresetn);
> +	if (ret) {
> +		dev_err(cru->dev, "failed to deassert aresetn\n");
> +		return ret;
> +	}
> +
> +	ret = reset_control_deassert(cru->presetn);
> +	if (ret) {
> +		reset_control_assert(cru->aresetn);
> +		dev_err(cru->dev, "failed to deassert presetn\n");
> +		return ret;
> +	}
> +
> +	ret = request_irq(cru->image_conv_irq, rzg2l_cru_irq,
> +			  IRQF_SHARED, KBUILD_MODNAME, cru);

Is there a reason for doing this here and not at probe time ?

> +	if (ret) {
> +		dev_err(cru->dev, "failed to request irq\n");
> +		goto assert_resets;
> +	}
> +
> +	/* Allocate scratch buffer. */
> +	cru->scratch = dma_alloc_coherent(cru->dev, cru->format.sizeimage,
> +					  &cru->scratch_phys, GFP_KERNEL);
> +	if (!cru->scratch) {
> +		return_unused_buffers(cru, VB2_BUF_STATE_QUEUED);
> +		dev_err(cru->dev, "Failed to allocate scratch buffer\n");
> +		goto free_image_conv_irq;
> +	}
> +
> +	cru->sequence = 0;
> +
> +	ret = rzg2l_cru_set_stream(cru, 1);
> +	if (ret) {
> +		return_unused_buffers(cru, VB2_BUF_STATE_QUEUED);
> +		goto out;
> +	}
> +
> +	cru->state = RZG2L_CRU_DMA_STARTING;
> +	dev_dbg(cru->dev, "Starting to capture\n");
> +	return 0;
> +
> +out:
> +	if (ret)
> +		dma_free_coherent(cru->dev, cru->format.sizeimage, cru->scratch,
> +				  cru->scratch_phys);
> +free_image_conv_irq:
> +	free_irq(cru->image_conv_irq, cru);
> +
> +assert_resets:
> +	reset_control_assert(cru->presetn);
> +	reset_control_assert(cru->aresetn);
> +
> +	return ret;
> +}
> +
> +static void rzg2l_cru_stop_streaming_vq(struct vb2_queue *vq)
> +{
> +	struct rzg2l_cru_dev *cru = vb2_get_drv_priv(vq);
> +
> +	rzg2l_cru_stop_streaming(cru);
> +
> +	/* Free scratch buffer */
> +	dma_free_coherent(cru->dev, cru->format.sizeimage,
> +			  cru->scratch, cru->scratch_phys);
> +
> +	free_irq(cru->image_conv_irq, cru);
> +	reset_control_assert(cru->presetn);
> +
> +	return_unused_buffers(cru, VB2_BUF_STATE_ERROR);
> +}
> +
> +static const struct vb2_ops rzg2l_cru_qops = {
> +	.queue_setup		= rzg2l_cru_queue_setup,
> +	.buf_prepare		= rzg2l_cru_buffer_prepare,
> +	.buf_queue		= rzg2l_cru_buffer_queue,
> +	.start_streaming	= rzg2l_cru_start_streaming_vq,
> +	.stop_streaming		= rzg2l_cru_stop_streaming_vq,
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +};
> +
> +void rzg2l_cru_dma_unregister(struct rzg2l_cru_dev *cru)
> +{
> +	mutex_destroy(&cru->lock);
> +
> +	v4l2_device_unregister(&cru->v4l2_dev);
> +	vb2_queue_release(&cru->queue);
> +}
> +
> +int rzg2l_cru_dma_register(struct rzg2l_cru_dev *cru)
> +{
> +	struct vb2_queue *q = &cru->queue;
> +	unsigned int i;
> +	int ret;
> +
> +	/* Initialize the top-level structure */
> +	ret = v4l2_device_register(cru->dev, &cru->v4l2_dev);
> +	if (ret)
> +		return ret;
> +
> +	mutex_init(&cru->lock);
> +	INIT_LIST_HEAD(&cru->buf_list);
> +
> +	spin_lock_init(&cru->qlock);
> +
> +	cru->state = RZG2L_CRU_DMA_STOPPED;
> +
> +	for (i = 0; i < RZG2L_CRU_HW_BUFFER_MAX; i++)
> +		cru->queue_buf[i] = NULL;
> +
> +	/* buffer queue */
> +	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	q->io_modes = VB2_MMAP | VB2_DMABUF;
> +	q->lock = &cru->lock;
> +	q->drv_priv = cru;
> +	q->buf_struct_size = sizeof(struct rzg2l_cru_buffer);
> +	q->ops = &rzg2l_cru_qops;
> +	q->mem_ops = &vb2_dma_contig_memops;
> +	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +	q->min_buffers_needed = 4;
> +	q->dev = cru->dev;
> +
> +	ret = vb2_queue_init(q);
> +	if (ret < 0) {
> +		dev_err(cru->dev, "failed to initialize VB2 queue\n");
> +		goto error;
> +	}
> +
> +	return 0;
> +
> +error:
> +	mutex_destroy(&cru->lock);
> +	v4l2_device_unregister(&cru->v4l2_dev);
> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 stuff
> + */
> +
> +static const struct v4l2_format_info rzg2l_cru_formats[] = {
> +	{
> +		.format = V4L2_PIX_FMT_UYVY,
> +		.bpp[0] = 2,
> +	},
> +};
> +
> +const struct v4l2_format_info *rzg2l_cru_format_from_pixel(u32 format)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(rzg2l_cru_formats); i++)
> +		if (rzg2l_cru_formats[i].format == format)
> +			return rzg2l_cru_formats + i;
> +
> +	return NULL;
> +}
> +
> +static u32 rzg2l_cru_format_bytesperline(struct v4l2_pix_format *pix)
> +{
> +	const struct v4l2_format_info *fmt;
> +
> +	fmt = rzg2l_cru_format_from_pixel(pix->pixelformat);
> +
> +	if (WARN_ON(!fmt))
> +		return -EINVAL;
> +
> +	return pix->width * fmt->bpp[0];
> +}
> +
> +static u32 rzg2l_cru_format_sizeimage(struct v4l2_pix_format *pix)
> +{
> +	return pix->bytesperline * pix->height;
> +}
> +
> +static void rzg2l_cru_format_align(struct rzg2l_cru_dev *cru,
> +				   struct v4l2_pix_format *pix)
> +{
> +	if (!rzg2l_cru_format_from_pixel(pix->pixelformat))
> +		pix->pixelformat = RZG2L_CRU_DEFAULT_FORMAT;
> +
> +	switch (pix->field) {
> +	case V4L2_FIELD_TOP:
> +	case V4L2_FIELD_BOTTOM:
> +	case V4L2_FIELD_NONE:
> +	case V4L2_FIELD_INTERLACED_TB:
> +	case V4L2_FIELD_INTERLACED_BT:
> +	case V4L2_FIELD_INTERLACED:
> +		break;
> +	default:
> +		pix->field = RZG2L_CRU_DEFAULT_FIELD;
> +		break;
> +	}
> +
> +	/* Limit to CRU capabilities */
> +	v4l_bound_align_image(&pix->width, 320, RZG2L_CRU_MAX_INPUT_WIDTH, 1,
> +			      &pix->height, 240, RZG2L_CRU_MAX_INPUT_HEIGHT, 2, 0);
> +
> +	pix->bytesperline = rzg2l_cru_format_bytesperline(pix);
> +	pix->sizeimage = rzg2l_cru_format_sizeimage(pix);
> +
> +	dev_dbg(cru->dev, "Format %ux%u bpl: %u size: %u\n",
> +		pix->width, pix->height, pix->bytesperline, pix->sizeimage);
> +}
> +
> +static void rzg2l_cru_try_format(struct rzg2l_cru_dev *cru,
> +				 struct v4l2_pix_format *pix)
> +{
> +	/*
> +	 * The V4L2 specification clearly documents the colorspace fields
> +	 * as being set by drivers for capture devices. Using the values
> +	 * supplied by userspace thus wouldn't comply with the API. Until
> +	 * the API is updated force fixed values.
> +	 */

For MC-based devices that's not right, but I'm OK if you don't address
it yet.

> +	pix->colorspace = RZG2L_CRU_DEFAULT_COLORSPACE;
> +	pix->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(pix->colorspace);
> +	pix->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(pix->colorspace);
> +	pix->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true, pix->colorspace,
> +							  pix->ycbcr_enc);
> +
> +	rzg2l_cru_format_align(cru, pix);
> +}
> +
> +static int rzg2l_cru_querycap(struct file *file, void *priv,
> +			      struct v4l2_capability *cap)
> +{
> +	struct rzg2l_cru_dev *cru = video_drvdata(file);
> +
> +	strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
> +	strscpy(cap->card, "RZG2L_CRU", sizeof(cap->card));
> +	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
> +		 dev_name(cru->dev));

You can drop bus_info, it's set by v4l_querycap().

> +	return 0;
> +}
> +
> +static int rzg2l_cru_try_fmt_vid_cap(struct file *file, void *priv,
> +				     struct v4l2_format *f)
> +{
> +	struct rzg2l_cru_dev *cru = video_drvdata(file);
> +
> +	rzg2l_cru_try_format(cru, &f->fmt.pix);
> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_s_fmt_vid_cap(struct file *file, void *priv,
> +				   struct v4l2_format *f)
> +{
> +	struct rzg2l_cru_dev *cru = video_drvdata(file);
> +
> +	if (vb2_is_busy(&cru->queue))
> +		return -EBUSY;
> +
> +	rzg2l_cru_try_format(cru, &f->fmt.pix);
> +
> +	cru->format = f->fmt.pix;
> +
> +	cru->compose.top = 0;
> +	cru->compose.left = 0;
> +	cru->compose.width = cru->format.width;
> +	cru->compose.height = cru->format.height;

As cru->compose is only set here, I'd drop it and use cru->format.width
and cru->format.height instead where needed.

> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_g_fmt_vid_cap(struct file *file, void *priv,
> +				   struct v4l2_format *f)
> +{
> +	struct rzg2l_cru_dev *cru = video_drvdata(file);
> +
> +	f->fmt.pix = cru->format;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_enum_fmt_vid_cap(struct file *file, void *priv,
> +				      struct v4l2_fmtdesc *f)
> +{
> +	if (f->index >= ARRAY_SIZE(rzg2l_cru_formats))
> +		return -EINVAL;
> +
> +	f->pixelformat = rzg2l_cru_formats[f->index].format;
> +
> +	return 0;
> +}
> +
> +static int rzg2l_cru_subscribe_event(struct v4l2_fh *fh,
> +				     const struct v4l2_event_subscription *sub)
> +{
> +	switch (sub->type) {
> +	case V4L2_EVENT_SOURCE_CHANGE:
> +		return v4l2_event_subscribe(fh, sub, 4, NULL);
> +	}
> +	return v4l2_ctrl_subscribe_event(fh, sub);
> +}
> +
> +static const struct v4l2_ioctl_ops rzg2l_cru_ioctl_ops = {
> +	.vidioc_querycap		= rzg2l_cru_querycap,
> +	.vidioc_try_fmt_vid_cap		= rzg2l_cru_try_fmt_vid_cap,
> +	.vidioc_g_fmt_vid_cap		= rzg2l_cru_g_fmt_vid_cap,
> +	.vidioc_s_fmt_vid_cap		= rzg2l_cru_s_fmt_vid_cap,
> +	.vidioc_enum_fmt_vid_cap	= rzg2l_cru_enum_fmt_vid_cap,
> +
> +	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
> +	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
> +	.vidioc_querybuf		= vb2_ioctl_querybuf,
> +	.vidioc_qbuf			= vb2_ioctl_qbuf,
> +	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
> +	.vidioc_expbuf			= vb2_ioctl_expbuf,
> +	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
> +	.vidioc_streamon		= vb2_ioctl_streamon,
> +	.vidioc_streamoff		= vb2_ioctl_streamoff,
> +
> +	.vidioc_log_status		= v4l2_ctrl_log_status,

The video node has no control, you can drop this.

> +	.vidioc_subscribe_event		= rzg2l_cru_subscribe_event,
> +	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,

Can this be dropped too, you never generate any event.

> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Media controller file operations
> + */
> +
> +static int rzg2l_cru_open(struct file *file)
> +{
> +	struct rzg2l_cru_dev *cru = video_drvdata(file);
> +	int ret;
> +
> +	ret = pm_runtime_resume_and_get(cru->dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_prepare_enable(cru->vclk);
> +	if (ret)
> +		goto disable_pm;

Do those two operations need to be done here, can't they be moved to
stream on time ?

> +
> +	ret = mutex_lock_interruptible(&cru->lock);
> +	if (ret)
> +		goto disable_vclk;
> +
> +	file->private_data = cru;
> +	ret = v4l2_fh_open(file);
> +	if (ret)
> +		goto err_unlock;
> +
> +	mutex_unlock(&cru->lock);
> +
> +	return 0;
> +
> +err_unlock:
> +	mutex_unlock(&cru->lock);
> +disable_vclk:
> +	clk_disable_unprepare(cru->vclk);
> +disable_pm:
> +	pm_runtime_put_sync(cru->dev);
> +
> +	return ret;
> +}
> +
> +static int rzg2l_cru_release(struct file *file)
> +{
> +	struct rzg2l_cru_dev *cru = video_drvdata(file);
> +	int ret;
> +
> +	mutex_lock(&cru->lock);
> +
> +	/* the release helper will cleanup any on-going streaming. */
> +	ret = _vb2_fop_release(file, NULL);
> +
> +	pm_runtime_put_sync(cru->dev);
> +	clk_disable_unprepare(cru->vclk);
> +
> +	mutex_unlock(&cru->lock);
> +
> +	return ret;
> +}
> +
> +static const struct v4l2_file_operations rzg2l_cru_fops = {
> +	.owner		= THIS_MODULE,
> +	.unlocked_ioctl	= video_ioctl2,
> +	.open		= rzg2l_cru_open,
> +	.release	= rzg2l_cru_release,
> +	.poll		= vb2_fop_poll,
> +	.mmap		= vb2_fop_mmap,
> +	.read		= vb2_fop_read,
> +};
> +
> +static void rzg2l_cru_v4l2_init(struct rzg2l_cru_dev *cru)
> +{
> +	struct video_device *vdev = &cru->vdev;
> +
> +	vdev->v4l2_dev = &cru->v4l2_dev;
> +	vdev->queue = &cru->queue;
> +	snprintf(vdev->name, sizeof(vdev->name), "CRU output");
> +	vdev->release = video_device_release_empty;
> +	vdev->lock = &cru->lock;
> +	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
> +	vdev->device_caps |= V4L2_CAP_IO_MC;
> +	vdev->fops = &rzg2l_cru_fops;
> +	vdev->ioctl_ops = &rzg2l_cru_ioctl_ops;
> +
> +	/* Set a default format */
> +	cru->format.pixelformat	= RZG2L_CRU_DEFAULT_FORMAT;
> +	cru->format.width = RZG2L_CRU_DEFAULT_WIDTH;
> +	cru->format.height = RZG2L_CRU_DEFAULT_HEIGHT;
> +	cru->format.field = RZG2L_CRU_DEFAULT_FIELD;
> +	cru->format.colorspace = RZG2L_CRU_DEFAULT_COLORSPACE;
> +	rzg2l_cru_format_align(cru, &cru->format);
> +}
> +
> +void rzg2l_cru_video_unregister(struct rzg2l_cru_dev *cru)
> +{
> +	video_unregister_device(&cru->vdev);
> +}
> +
> +int rzg2l_cru_video_register(struct rzg2l_cru_dev *cru)
> +{
> +	struct video_device *vdev = &cru->vdev;
> +	int ret;
> +
> +	if (video_is_registered(&cru->vdev)) {
> +		struct media_entity *entity;
> +
> +		entity = &cru->vdev.entity;
> +		if (!entity->graph_obj.mdev)
> +			entity->graph_obj.mdev = &cru->mdev;
> +		return 0;
> +	}
> +
> +	rzg2l_cru_v4l2_init(cru);
> +	video_set_drvdata(vdev, cru);
> +	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
> +	if (ret) {
> +		dev_err(cru->dev, "Failed to register video device\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}

Hi Prabhakar,

On Wed, Nov 02, 2022 at 12:43:29AM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Add v4l driver for Renesas RZ/G2L Camera data Receiving Unit.
> 
> Based on a patch in the BSP by Hien Huynh
> <hien.huynh.px@renesas.com>
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Laurent's comment arrive a little late but the patch does not compile
against the media tree anymore. The argument of the media_pipeline_start()
and media_pipeline_stop() is now a pad, not an entity. See what the changes
look like in other drivers (the commit id is
12cecbf9150f67b0ce7d88bc2e243e67637726c2).

I'll still take the DT binding patches.

Hi Prabhakar,

On Tue, Nov 22, 2022 at 10:26:28AM +0000, Lad, Prabhakar wrote:
> Hi Sakari,
> 
> On Tue, Nov 22, 2022 at 9:38 AM Sakari Ailus
> <sakari.ailus@linux.intel.com> wrote:
> >
> > Hi Prabhakar,
> >
> > On Wed, Nov 02, 2022 at 12:43:29AM +0000, Prabhakar wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Add v4l driver for Renesas RZ/G2L Camera data Receiving Unit.
> > >
> > > Based on a patch in the BSP by Hien Huynh
> > > <hien.huynh.px@renesas.com>
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Laurent's comment arrive a little late but the patch does not compile
> > against the media tree anymore. The argument of the media_pipeline_start()
> > and media_pipeline_stop() is now a pad, not an entity. See what the changes
> > look like in other drivers (the commit id is
> > 12cecbf9150f67b0ce7d88bc2e243e67637726c2).
> >
> I'll go through them soon, when do you plan to close the v6.2 window?
> 
> > I'll still take the DT binding patches.
> >
> Or maybe we could wait and get them alongside the drivers?

Can you send a new version by tomorrow morning (Finnish time)? The needed
changes didn't seem too complicated, I wouldn't want to delay my PR much
later as chances slipping to 6.3 will increase.

Hi Laurent,

On Tue, Nov 22, 2022 at 8:28 PM Lad, Prabhakar
<prabhakar.csengg@gmail.com> wrote:
>
> Hi Laurent,
>
> Thank you for the review.
>
> On Tue, Nov 22, 2022 at 2:00 AM Laurent Pinchart
> <laurent.pinchart@ideasonboard.com> wrote:
> >
> > Hi Prabhakar,
> >
> > Thank you for the patch.
> >
> > On Wed, Nov 02, 2022 at 12:43:29AM +0000, Prabhakar wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Add v4l driver for Renesas RZ/G2L Camera data Receiving Unit.
> > >
> > > Based on a patch in the BSP by Hien Huynh
> > > <hien.huynh.px@renesas.com>
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > > -v4 -> v5
> > > * Made sure we call pre_streamon/post_streamoff around s_stream
> > > * Made sure to cleanup on error path in s_stream
> > > * Dropped pre_streamon/post_streamoff callbacks from IP subdev
> > > * Moved the CRU start/stop configuration to IP subdev to avoid
> > >   recursively calling pre_streamon/post_streamoff callbacks.
> > >
> > > -v3 -> v4
> > > * Undoing the configuration in case s_stream(1) fails
> > > * Made sure we call post_streamoff in the error path of s_stream(1)
> > >
> > > v2 -> v3
> > > * Switched to PM runtime
> > > * Modeled CRU IP block as a subdev
> > > * Dropped explicitly selecting VIDEO_RZG2L_CSI2 for VIDEO_RZG2L_CRU config
> > > * Replaced v4l2_dev_to_cru macro with inline function notifier_to_cru()
> > > * Dropped id parameter from rvin_mc_parse_of()
> > > * Renamed rzg2l_cru_csi2_init() -> rzg2l_cru_media_init()
> > > * Used dev_err_probe() in rzg2l_cru_probe()
> > > * Replaced devm_reset_control_get() -> devm_reset_control_get_exclusive()
> > > * Prefixed HW_BUFFER_MAX and HW_BUFFER_DEFAULT macros with RZG2L_CRU_
> > > * Moved asserting presetn signal from rzg2l_cru_dma_register() to rzg2l_cru_start_streaming_vq()
> > > * Dropped VB2_READ from VB2 io_modes
> > > * Used dev_dbg() in rzg2l_cru_video_register() and rzg2l_cru_video_unregister()
> > > * Got rid of rzg2l_cru_notify()
> > > * Dropped V4L2_CAP_READWRITE from device caps
> > > * Introduced rzg2l_cru_v4l2_init() for initialization.
> > > * Got rid v4l2_pipeline_pm_get() and used PM in ov5645 sensor driver. Patch posted
> > >   https://patchwork.linuxtv.org/project/linux-media/patch/20220927201634.750141-1-prabhakar.mahadev-lad.rj@bp.renesas.com/
> > >
> > > v1 -> v2
> > > * No change
> > >
> > > RFC v2 -> v1
> > > * Moved the driver to renesas folder
> > > * Fixed review comments pointed by Jacopo
> > >
> > > RFC v1 -> RFC v2
> > > * Dropped group
> > > * Dropped CSI subdev and implemented as new driver
> > > * Dropped "mc_" from function names
> > > * Moved the driver to renesas folder
> > > ---
> > >  .../media/platform/renesas/rzg2l-cru/Kconfig  |   16 +
> > >  .../media/platform/renesas/rzg2l-cru/Makefile |    3 +
> > >  .../platform/renesas/rzg2l-cru/rzg2l-core.c   |  370 ++++++
> > >  .../platform/renesas/rzg2l-cru/rzg2l-cru.h    |  169 +++
> > >  .../platform/renesas/rzg2l-cru/rzg2l-ip.c     |  283 +++++
> > >  .../platform/renesas/rzg2l-cru/rzg2l-video.c  | 1086 +++++++++++++++++
> > >  6 files changed, 1927 insertions(+)
> > >  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
> > >  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
> > >  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> > >  create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > >
> > > diff --git a/drivers/media/platform/renesas/rzg2l-cru/Kconfig b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> > > index 57c40bb499df..b39818c1f053 100644
> > > --- a/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> > > +++ b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> > > @@ -15,3 +15,19 @@ config VIDEO_RZG2L_CSI2
> > >
> > >         To compile this driver as a module, choose M here: the
> > >         module will be called rzg2l-csi2.
> > > +
> > > +config VIDEO_RZG2L_CRU
> > > +     tristate "RZ/G2L Camera Receiving Unit (CRU) Driver"
> > > +     depends on ARCH_RENESAS || COMPILE_TEST
> > > +     depends on V4L_PLATFORM_DRIVERS
> > > +     depends on VIDEO_DEV && OF
> > > +     select MEDIA_CONTROLLER
> > > +     select V4L2_FWNODE
> > > +     select VIDEOBUF2_DMA_CONTIG
> > > +     select VIDEO_V4L2_SUBDEV_API
> > > +     help
> > > +       Support for Renesas RZ/G2L (and alike SoC's) Camera Receiving
> > > +       Unit (CRU) driver.
> > > +
> > > +       To compile this driver as a module, choose M here: the
> > > +       module will be called rzg2l-cru.
> > > diff --git a/drivers/media/platform/renesas/rzg2l-cru/Makefile b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> > > index 91ea97a944e6..c4db2632874f 100644
> > > --- a/drivers/media/platform/renesas/rzg2l-cru/Makefile
> > > +++ b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> > > @@ -1,3 +1,6 @@
> > >  # SPDX-License-Identifier: GPL-2.0
> > >
> > >  obj-$(CONFIG_VIDEO_RZG2L_CSI2) += rzg2l-csi2.o
> > > +
> > > +rzg2l-cru-objs = rzg2l-core.o rzg2l-ip.o rzg2l-video.o
> > > +obj-$(CONFIG_VIDEO_RZG2L_CRU) += rzg2l-cru.o
> > > diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
> > > new file mode 100644
> > > index 000000000000..7a92fcfee84c
> > > --- /dev/null
> > > +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-core.c
> > > @@ -0,0 +1,370 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +/*
> > > + * Driver for Renesas RZ/G2L CRU
> > > + *
> > > + * Copyright (C) 2022 Renesas Electronics Corp.
> > > + *
> > > + * Based on Renesas R-Car VIN
> > > + * Copyright (C) 2011-2013 Renesas Solutions Corp.
> > > + * Copyright (C) 2013 Cogent Embedded, Inc., <source@cogentembedded.com>
> > > + * Copyright (C) 2008 Magnus Damm
> > > + */
> > > +
> > > +#include <linux/clk.h>
> > > +#include <linux/module.h>
> > > +#include <linux/mod_devicetable.h>
> > > +#include <linux/of.h>
> > > +#include <linux/of_device.h>
> > > +#include <linux/of_graph.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/pm_runtime.h>
> > > +
> > > +#include <media/v4l2-fwnode.h>
> > > +#include <media/v4l2-mc.h>
> > > +
> > > +#include "rzg2l-cru.h"
> > > +
> > > +static inline struct rzg2l_cru_dev *notifier_to_cru(struct v4l2_async_notifier *n)
> > > +{
> > > +     return container_of(n, struct rzg2l_cru_dev, notifier);
> > > +}
> > > +
> > > +static int rzg2l_cru_csi2_link_notify(struct media_link *link, u32 flags,
> > > +                                   unsigned int notification)
> > > +{
> > > +     struct media_entity *entity;
> > > +     struct rzg2l_cru_dev *cru;
> > > +     int ret;
> > > +
> > > +     ret = v4l2_pipeline_link_notify(link, flags, notification);
> > > +     if (ret)
> > > +             return ret;
> > > +
> > > +     /* Only care about link enablement for CRU nodes. */
> > > +     if (!(flags & MEDIA_LNK_FL_ENABLED))
> > > +             return 0;
> > > +
> > > +     cru = container_of(link->graph_obj.mdev, struct rzg2l_cru_dev, mdev);
> > > +     /*
> > > +      * Don't allow link changes if any entity in the graph is
> > > +      * streaming, modifying the CHSEL register fields can disrupt
> > > +      * running streams.
> > > +      */
> > > +     media_device_for_each_entity(entity, &cru->mdev)
> > > +             if (media_entity_is_streaming(entity))
> > > +                     return -EBUSY;
> > > +
> > > +     mutex_lock(&cru->mdev_lock);
> > > +     if (media_pad_remote_pad_first(&cru->vdev.entity.pads[0]))
> > > +             ret = -EMLINK;
> > > +     mutex_unlock(&cru->mdev_lock);
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +static const struct media_device_ops rzg2l_cru_media_ops = {
> > > +     .link_notify = rzg2l_cru_csi2_link_notify,
> > > +};
> > > +
> > > +/* -----------------------------------------------------------------------------
> > > + * Group async notifier
> > > + */
> > > +
> > > +static int rzg2l_cru_group_notify_complete(struct v4l2_async_notifier *notifier)
> > > +{
> > > +     struct rzg2l_cru_dev *cru = notifier_to_cru(notifier);
> > > +     struct media_entity *source, *sink;
> > > +     int ret;
> > > +
> > > +     ret = media_device_register(&cru->mdev);
> > > +     if (ret)
> > > +             return ret;
> >
> > I'd move the v4l2_device_register() call here, as it's the V4L2
> > counterpart of the media device, and handling them together would be
> > best.
> >
> OK, but now that we plan to get rid of rzg2l_cru_csi2_link_notify()
> I'll move this call into rzg2l_cru_dma_register().
>
I misread the comment earlier, I will get rid of
rzg2l_cru_csi2_link_notify() and use v4l2_pipeline_link_notify()
instead. And I will also move the media_device_register() into
rzg2l_cru_dma_register().

Cheers,
Prabhakar