[v7,01/28] media: sun6i-csi: Add bridge v4l2 subdev with port management

Message ID 20221103163113.245462-2-paul.kocialkowski@bootlin.com
State New
Headers
Series Allwinner A31/A83T MIPI CSI-2 and A31 ISP / CSI Rework |

Commit Message

Paul Kocialkowski Nov. 3, 2022, 4:30 p.m. UTC
  Introduce a bridge v4l2 subdev to prepare for separation between the
processing part (bridge) and the dma engine, which is required to
properly support ths isp workflow later on.

Currently the bridge just manages fwnode mapping to media pads,
using an async notifier (which was previously in the main code).
The s_stream video op just forwards to the connected v4l2 subdev
(sensor or MIPI CSI-2 bridge).

The video capture device is now registered after the bridge and
attaches to it with a media link.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 .../media/platform/sunxi/sun6i-csi/Makefile   |   2 +-
 .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 157 +-----
 .../platform/sunxi/sun6i-csi/sun6i_csi.h      |  10 +-
 .../sunxi/sun6i-csi/sun6i_csi_bridge.c        | 450 ++++++++++++++++++
 .../sunxi/sun6i-csi/sun6i_csi_bridge.h        |  49 ++
 .../platform/sunxi/sun6i-csi/sun6i_video.c    |  19 +
 6 files changed, 548 insertions(+), 139 deletions(-)
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c
 create mode 100644 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.h
  

Comments

kernel test robot Nov. 9, 2022, 6:23 p.m. UTC | #1
Hi Paul,

I love your patch! Perhaps something to improve:

[auto build test WARNING on media-tree/master]
[also build test WARNING on soc/for-next linus/master v6.1-rc4 next-20221109]
[cannot apply to sailus-media-tree/streams]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Paul-Kocialkowski/Allwinner-A31-A83T-MIPI-CSI-2-and-A31-ISP-CSI-Rework/20221104-003518
base:   git://linuxtv.org/media_tree.git master
patch link:    https://lore.kernel.org/r/20221103163113.245462-2-paul.kocialkowski%40bootlin.com
patch subject: [PATCH v7 01/28] media: sun6i-csi: Add bridge v4l2 subdev with port management
config: arm64-allyesconfig
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 463da45892e2d2a262277b91b96f5f8c05dc25d0)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/d26de0b15ad9da72e89a53abb74503a11cc6a1b9
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Paul-Kocialkowski/Allwinner-A31-A83T-MIPI-CSI-2-and-A31-ISP-CSI-Rework/20221104-003518
        git checkout d26de0b15ad9da72e89a53abb74503a11cc6a1b9
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/gpio/ drivers/gpu/drm/ drivers/media/platform/sunxi/sun6i-csi/ drivers/thermal/intel/ drivers/usb/gadget/udc/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c:272:2: warning: variable 'enabled' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
           default:
           ^~~~~~~
   drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c:279:25: note: uninitialized use occurs here
                                        remote_subdev, enabled);
                                                       ^~~~~~~
   drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c:266:14: note: initialize the variable 'enabled' to silence this warning
           bool enabled;
                       ^
                        = 0
   1 warning generated.


vim +/enabled +272 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c

   253	
   254	static int
   255	sun6i_csi_bridge_notifier_bound(struct v4l2_async_notifier *notifier,
   256					struct v4l2_subdev *remote_subdev,
   257					struct v4l2_async_subdev *async_subdev)
   258	{
   259		struct sun6i_csi_device *csi_dev =
   260			container_of(notifier, struct sun6i_csi_device,
   261				     bridge.notifier);
   262		struct sun6i_csi_bridge_async_subdev *bridge_async_subdev =
   263			container_of(async_subdev, struct sun6i_csi_bridge_async_subdev,
   264				     async_subdev);
   265		struct sun6i_csi_bridge_source *source = bridge_async_subdev->source;
   266		bool enabled;
   267	
   268		switch (source->endpoint.base.port) {
   269		case SUN6I_CSI_PORT_PARALLEL:
   270			enabled = true;
   271			break;
 > 272		default:
   273			break;
   274		}
   275	
   276		source->subdev = remote_subdev;
   277	
   278		return sun6i_csi_bridge_link(csi_dev, SUN6I_CSI_BRIDGE_PAD_SINK,
   279					     remote_subdev, enabled);
   280	}
   281
  
Dan Carpenter Nov. 10, 2022, 6:57 a.m. UTC | #2
Hi Paul,

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Paul-Kocialkowski/Allwinner-A31-A83T-MIPI-CSI-2-and-A31-ISP-CSI-Rework/20221104-003518
base:   git://linuxtv.org/media_tree.git master
patch link:    https://lore.kernel.org/r/20221103163113.245462-2-paul.kocialkowski%40bootlin.com
patch subject: [PATCH v7 01/28] media: sun6i-csi: Add bridge v4l2 subdev with port management
config: arc-randconfig-m041-20221107
compiler: arc-elf-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>

smatch warnings:
drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c:86 sun6i_csi_bridge_s_stream() warn: missing error code 'ret'
drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c:279 sun6i_csi_bridge_notifier_bound() error: uninitialized symbol 'enabled'.

vim +/ret +86 drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c

d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   62  static int sun6i_csi_bridge_s_stream(struct v4l2_subdev *subdev, int on)
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   63  {
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   64  	struct sun6i_csi_device *csi_dev = v4l2_get_subdevdata(subdev);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   65  	struct sun6i_csi_bridge *bridge = &csi_dev->bridge;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   66  	struct media_pad *local_pad = &bridge->pads[SUN6I_CSI_BRIDGE_PAD_SINK];
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   67  	struct device *dev = csi_dev->dev;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   68  	struct v4l2_subdev *source_subdev;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   69  	struct media_pad *remote_pad;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   70  	/* Initialize to 0 to use both in disable label (ret != 0) and off. */
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   71  	int ret = 0;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   72  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   73  	/* Source */
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   74  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   75  	remote_pad = media_pad_remote_pad_unique(local_pad);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   76  	if (IS_ERR(remote_pad)) {
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   77  		dev_err(dev,
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   78  			"zero or more than a single source connected to the bridge\n");
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   79  		return PTR_ERR(remote_pad);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   80  	}
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   81  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   82  	source_subdev = media_entity_to_v4l2_subdev(remote_pad->entity);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   83  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   84  	if (!on) {
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   85  		v4l2_subdev_call(source_subdev, video, s_stream, 0);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  @86  		goto disable;

This is intentional, but it should just return 0;

d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   87  	}
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   88  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   89  	ret = v4l2_subdev_call(source_subdev, video, s_stream, 1);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   90  	if (ret && ret != -ENOIOCTLCMD)
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   91  		goto disable;

Do we really need to clean anything up?  Why not just:

	source_subdev = media_entity_to_v4l2_subdev(remote_pad->entity);

	return v4l2_subdev_call(source_subdev, video, s_stream, !!on);

d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   92  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   93  	return 0;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   94  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   95  disable:
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   96  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   97  	return ret;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   98  }
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03   99  

[ snip ]

d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  254  static int
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  255  sun6i_csi_bridge_notifier_bound(struct v4l2_async_notifier *notifier,
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  256  				struct v4l2_subdev *remote_subdev,
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  257  				struct v4l2_async_subdev *async_subdev)
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  258  {
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  259  	struct sun6i_csi_device *csi_dev =
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  260  		container_of(notifier, struct sun6i_csi_device,
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  261  			     bridge.notifier);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  262  	struct sun6i_csi_bridge_async_subdev *bridge_async_subdev =
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  263  		container_of(async_subdev, struct sun6i_csi_bridge_async_subdev,
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  264  			     async_subdev);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  265  	struct sun6i_csi_bridge_source *source = bridge_async_subdev->source;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  266  	bool enabled;

This neesds to be "bool enabled = false;"

d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  267  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  268  	switch (source->endpoint.base.port) {
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  269  	case SUN6I_CSI_PORT_PARALLEL:
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  270  		enabled = true;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  271  		break;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  272  	default:
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  273  		break;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  274  	}
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  275  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  276  	source->subdev = remote_subdev;
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  277  
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  278  	return sun6i_csi_bridge_link(csi_dev, SUN6I_CSI_BRIDGE_PAD_SINK,
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03 @279  				     remote_subdev, enabled);
d26de0b15ad9da7 Paul Kocialkowski 2022-11-03  280  }
  

Patch

diff --git a/drivers/media/platform/sunxi/sun6i-csi/Makefile b/drivers/media/platform/sunxi/sun6i-csi/Makefile
index e7e315347804..7a699580a641 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/Makefile
+++ b/drivers/media/platform/sunxi/sun6i-csi/Makefile
@@ -1,4 +1,4 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
-sun6i-csi-y += sun6i_video.o sun6i_csi.o
+sun6i-csi-y += sun6i_video.o sun6i_csi.o sun6i_csi_bridge.o
 
 obj-$(CONFIG_VIDEO_SUN6I_CSI) += sun6i-csi.o
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
index 8b99c17e8403..49f1218b0b28 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
@@ -34,16 +34,17 @@ 
 bool sun6i_csi_is_format_supported(struct sun6i_csi_device *csi_dev,
 				   u32 pixformat, u32 mbus_code)
 {
-	struct sun6i_csi_v4l2 *v4l2 = &csi_dev->v4l2;
+	struct v4l2_fwnode_endpoint *endpoint =
+		&csi_dev->bridge.source_parallel.endpoint;
 
 	/*
 	 * Some video receivers have the ability to be compatible with
 	 * 8bit and 16bit bus width.
 	 * Identify the media bus format from device tree.
 	 */
-	if ((v4l2->v4l2_ep.bus_type == V4L2_MBUS_PARALLEL
-	     || v4l2->v4l2_ep.bus_type == V4L2_MBUS_BT656)
-	     && v4l2->v4l2_ep.bus.parallel.bus_width == 16) {
+	if ((endpoint->bus_type == V4L2_MBUS_PARALLEL
+	     || endpoint->bus_type == V4L2_MBUS_BT656)
+	     && endpoint->bus.parallel.bus_width == 16) {
 		switch (pixformat) {
 		case V4L2_PIX_FMT_NV12_16L16:
 		case V4L2_PIX_FMT_NV12:
@@ -328,7 +329,8 @@  static enum csi_input_seq get_csi_input_seq(struct sun6i_csi_device *csi_dev,
 
 static void sun6i_csi_setup_bus(struct sun6i_csi_device *csi_dev)
 {
-	struct v4l2_fwnode_endpoint *endpoint = &csi_dev->v4l2.v4l2_ep;
+	struct v4l2_fwnode_endpoint *endpoint =
+		&csi_dev->bridge.source_parallel.endpoint;
 	struct sun6i_csi_config *config = &csi_dev->config;
 	unsigned char bus_width;
 	u32 flags;
@@ -583,103 +585,11 @@  static const struct media_device_ops sun6i_csi_media_ops = {
 
 /* V4L2 */
 
-static int sun6i_csi_link_entity(struct sun6i_csi_device *csi_dev,
-				 struct media_entity *entity,
-				 struct fwnode_handle *fwnode)
-{
-	struct media_entity *sink;
-	struct media_pad *sink_pad;
-	int src_pad_index;
-	int ret;
-
-	ret = media_entity_get_fwnode_pad(entity, fwnode, MEDIA_PAD_FL_SOURCE);
-	if (ret < 0) {
-		dev_err(csi_dev->dev,
-			"%s: no source pad in external entity %s\n", __func__,
-			entity->name);
-		return -EINVAL;
-	}
-
-	src_pad_index = ret;
-
-	sink = &csi_dev->video.video_dev.entity;
-	sink_pad = &csi_dev->video.pad;
-
-	dev_dbg(csi_dev->dev, "creating %s:%u -> %s:%u link\n",
-		entity->name, src_pad_index, sink->name, sink_pad->index);
-	ret = media_create_pad_link(entity, src_pad_index, sink,
-				    sink_pad->index,
-				    MEDIA_LNK_FL_ENABLED |
-				    MEDIA_LNK_FL_IMMUTABLE);
-	if (ret < 0) {
-		dev_err(csi_dev->dev, "failed to create %s:%u -> %s:%u link\n",
-			entity->name, src_pad_index,
-			sink->name, sink_pad->index);
-		return ret;
-	}
-
-	return 0;
-}
-
-static int sun6i_subdev_notify_complete(struct v4l2_async_notifier *notifier)
-{
-	struct sun6i_csi_device *csi_dev =
-		container_of(notifier, struct sun6i_csi_device,
-			     v4l2.notifier);
-	struct sun6i_csi_v4l2 *v4l2 = &csi_dev->v4l2;
-	struct v4l2_device *v4l2_dev = &v4l2->v4l2_dev;
-	struct v4l2_subdev *sd;
-	int ret;
-
-	dev_dbg(csi_dev->dev, "notify complete, all subdevs registered\n");
-
-	sd = list_first_entry(&v4l2_dev->subdevs, struct v4l2_subdev, list);
-	if (!sd)
-		return -EINVAL;
-
-	ret = sun6i_csi_link_entity(csi_dev, &sd->entity, sd->fwnode);
-	if (ret < 0)
-		return ret;
-
-	ret = v4l2_device_register_subdev_nodes(v4l2_dev);
-	if (ret < 0)
-		return ret;
-
-	return 0;
-}
-
-static const struct v4l2_async_notifier_operations sun6i_csi_async_ops = {
-	.complete = sun6i_subdev_notify_complete,
-};
-
-static int sun6i_csi_fwnode_parse(struct device *dev,
-				  struct v4l2_fwnode_endpoint *vep,
-				  struct v4l2_async_subdev *asd)
-{
-	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
-
-	if (vep->base.port || vep->base.id) {
-		dev_warn(dev, "Only support a single port with one endpoint\n");
-		return -ENOTCONN;
-	}
-
-	switch (vep->bus_type) {
-	case V4L2_MBUS_PARALLEL:
-	case V4L2_MBUS_BT656:
-		csi_dev->v4l2.v4l2_ep = *vep;
-		return 0;
-	default:
-		dev_err(dev, "Unsupported media bus type\n");
-		return -ENOTCONN;
-	}
-}
-
 static int sun6i_csi_v4l2_setup(struct sun6i_csi_device *csi_dev)
 {
 	struct sun6i_csi_v4l2 *v4l2 = &csi_dev->v4l2;
 	struct media_device *media_dev = &v4l2->media_dev;
 	struct v4l2_device *v4l2_dev = &v4l2->v4l2_dev;
-	struct v4l2_async_notifier *notifier = &v4l2->notifier;
 	struct device *dev = csi_dev->dev;
 	int ret;
 
@@ -709,42 +619,8 @@  static int sun6i_csi_v4l2_setup(struct sun6i_csi_device *csi_dev)
 		goto error_media;
 	}
 
-	/* Video */
-
-	ret = sun6i_video_setup(csi_dev);
-	if (ret)
-		goto error_v4l2_device;
-
-	/* V4L2 Async */
-
-	v4l2_async_nf_init(notifier);
-	notifier->ops = &sun6i_csi_async_ops;
-
-	ret = v4l2_async_nf_parse_fwnode_endpoints(dev, notifier,
-						   sizeof(struct
-							  v4l2_async_subdev),
-						   sun6i_csi_fwnode_parse);
-	if (ret)
-		goto error_video;
-
-	ret = v4l2_async_nf_register(v4l2_dev, notifier);
-	if (ret) {
-		dev_err(dev, "failed to register v4l2 async notifier: %d\n",
-			ret);
-		goto error_v4l2_async_notifier;
-	}
-
 	return 0;
 
-error_v4l2_async_notifier:
-	v4l2_async_nf_cleanup(notifier);
-
-error_video:
-	sun6i_video_cleanup(csi_dev);
-
-error_v4l2_device:
-	v4l2_device_unregister(&v4l2->v4l2_dev);
-
 error_media:
 	media_device_unregister(media_dev);
 	media_device_cleanup(media_dev);
@@ -757,9 +633,6 @@  static void sun6i_csi_v4l2_cleanup(struct sun6i_csi_device *csi_dev)
 	struct sun6i_csi_v4l2 *v4l2 = &csi_dev->v4l2;
 
 	media_device_unregister(&v4l2->media_dev);
-	v4l2_async_nf_unregister(&v4l2->notifier);
-	v4l2_async_nf_cleanup(&v4l2->notifier);
-	sun6i_video_cleanup(csi_dev);
 	v4l2_device_unregister(&v4l2->v4l2_dev);
 	media_device_cleanup(&v4l2->media_dev);
 }
@@ -964,8 +837,22 @@  static int sun6i_csi_probe(struct platform_device *platform_dev)
 	if (ret)
 		goto error_resources;
 
+	ret = sun6i_csi_bridge_setup(csi_dev);
+	if (ret)
+		goto error_v4l2;
+
+	ret = sun6i_video_setup(csi_dev);
+	if (ret)
+		goto error_bridge;
+
 	return 0;
 
+error_bridge:
+	sun6i_csi_bridge_cleanup(csi_dev);
+
+error_v4l2:
+	sun6i_csi_v4l2_cleanup(csi_dev);
+
 error_resources:
 	sun6i_csi_resources_cleanup(csi_dev);
 
@@ -976,6 +863,8 @@  static int sun6i_csi_remove(struct platform_device *pdev)
 {
 	struct sun6i_csi_device *csi_dev = platform_get_drvdata(pdev);
 
+	sun6i_video_cleanup(csi_dev);
+	sun6i_csi_bridge_cleanup(csi_dev);
 	sun6i_csi_v4l2_cleanup(csi_dev);
 	sun6i_csi_resources_cleanup(csi_dev);
 
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
index bab705678280..1dd76631ec87 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h
@@ -12,11 +12,16 @@ 
 #include <media/v4l2-fwnode.h>
 #include <media/videobuf2-v4l2.h>
 
+#include "sun6i_csi_bridge.h"
 #include "sun6i_video.h"
 
 #define SUN6I_CSI_NAME		"sun6i-csi"
 #define SUN6I_CSI_DESCRIPTION	"Allwinner A31 CSI Device"
 
+enum sun6i_csi_port {
+	SUN6I_CSI_PORT_PARALLEL		= 0,
+};
+
 struct sun6i_csi_buffer {
 	struct vb2_v4l2_buffer		v4l2_buffer;
 	struct list_head		list;
@@ -44,10 +49,6 @@  struct sun6i_csi_config {
 struct sun6i_csi_v4l2 {
 	struct v4l2_device		v4l2_dev;
 	struct media_device		media_dev;
-
-	struct v4l2_async_notifier	notifier;
-	/* video port settings */
-	struct v4l2_fwnode_endpoint	v4l2_ep;
 };
 
 struct sun6i_csi_device {
@@ -55,6 +56,7 @@  struct sun6i_csi_device {
 
 	struct sun6i_csi_config		config;
 	struct sun6i_csi_v4l2		v4l2;
+	struct sun6i_csi_bridge		bridge;
 	struct sun6i_video		video;
 
 	struct regmap			*regmap;
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c
new file mode 100644
index 000000000000..cac1b150e544
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c
@@ -0,0 +1,450 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021-2022 Bootlin
+ * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+ */
+
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+
+#include "sun6i_csi.h"
+#include "sun6i_csi_bridge.h"
+
+/* Format */
+
+static const u32 sun6i_csi_bridge_mbus_codes[] = {
+	/* Bayer */
+	MEDIA_BUS_FMT_SBGGR8_1X8,
+	MEDIA_BUS_FMT_SGBRG8_1X8,
+	MEDIA_BUS_FMT_SGRBG8_1X8,
+	MEDIA_BUS_FMT_SRGGB8_1X8,
+	MEDIA_BUS_FMT_SBGGR10_1X10,
+	MEDIA_BUS_FMT_SGBRG10_1X10,
+	MEDIA_BUS_FMT_SGRBG10_1X10,
+	MEDIA_BUS_FMT_SRGGB10_1X10,
+	MEDIA_BUS_FMT_SBGGR12_1X12,
+	MEDIA_BUS_FMT_SGBRG12_1X12,
+	MEDIA_BUS_FMT_SGRBG12_1X12,
+	MEDIA_BUS_FMT_SRGGB12_1X12,
+	/* RGB */
+	MEDIA_BUS_FMT_RGB565_2X8_LE,
+	MEDIA_BUS_FMT_RGB565_2X8_BE,
+	/* YUV422 */
+	MEDIA_BUS_FMT_YUYV8_2X8,
+	MEDIA_BUS_FMT_UYVY8_2X8,
+	MEDIA_BUS_FMT_YVYU8_2X8,
+	MEDIA_BUS_FMT_UYVY8_2X8,
+	MEDIA_BUS_FMT_VYUY8_2X8,
+	MEDIA_BUS_FMT_YUYV8_1X16,
+	MEDIA_BUS_FMT_UYVY8_1X16,
+	MEDIA_BUS_FMT_YVYU8_1X16,
+	MEDIA_BUS_FMT_UYVY8_1X16,
+	MEDIA_BUS_FMT_VYUY8_1X16,
+	/* Compressed */
+	MEDIA_BUS_FMT_JPEG_1X8,
+};
+
+static bool sun6i_csi_bridge_mbus_code_check(u32 mbus_code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(sun6i_csi_bridge_mbus_codes); i++)
+		if (sun6i_csi_bridge_mbus_codes[i] == mbus_code)
+			return true;
+
+	return false;
+}
+
+/* V4L2 Subdev */
+
+static int sun6i_csi_bridge_s_stream(struct v4l2_subdev *subdev, int on)
+{
+	struct sun6i_csi_device *csi_dev = v4l2_get_subdevdata(subdev);
+	struct sun6i_csi_bridge *bridge = &csi_dev->bridge;
+	struct media_pad *local_pad = &bridge->pads[SUN6I_CSI_BRIDGE_PAD_SINK];
+	struct device *dev = csi_dev->dev;
+	struct v4l2_subdev *source_subdev;
+	struct media_pad *remote_pad;
+	/* Initialize to 0 to use both in disable label (ret != 0) and off. */
+	int ret = 0;
+
+	/* Source */
+
+	remote_pad = media_pad_remote_pad_unique(local_pad);
+	if (IS_ERR(remote_pad)) {
+		dev_err(dev,
+			"zero or more than a single source connected to the bridge\n");
+		return PTR_ERR(remote_pad);
+	}
+
+	source_subdev = media_entity_to_v4l2_subdev(remote_pad->entity);
+
+	if (!on) {
+		v4l2_subdev_call(source_subdev, video, s_stream, 0);
+		goto disable;
+	}
+
+	ret = v4l2_subdev_call(source_subdev, video, s_stream, 1);
+	if (ret && ret != -ENOIOCTLCMD)
+		goto disable;
+
+	return 0;
+
+disable:
+
+	return ret;
+}
+
+static const struct v4l2_subdev_video_ops sun6i_csi_bridge_video_ops = {
+	.s_stream	= sun6i_csi_bridge_s_stream,
+};
+
+static void
+sun6i_csi_bridge_mbus_format_prepare(struct v4l2_mbus_framefmt *mbus_format)
+{
+	if (!sun6i_csi_bridge_mbus_code_check(mbus_format->code))
+		mbus_format->code = sun6i_csi_bridge_mbus_codes[0];
+
+	mbus_format->field = V4L2_FIELD_NONE;
+	mbus_format->colorspace = V4L2_COLORSPACE_RAW;
+	mbus_format->quantization = V4L2_QUANTIZATION_DEFAULT;
+	mbus_format->xfer_func = V4L2_XFER_FUNC_DEFAULT;
+}
+
+static int sun6i_csi_bridge_init_cfg(struct v4l2_subdev *subdev,
+				     struct v4l2_subdev_state *state)
+{
+	struct sun6i_csi_device *csi_dev = v4l2_get_subdevdata(subdev);
+	unsigned int pad = SUN6I_CSI_BRIDGE_PAD_SINK;
+	struct v4l2_mbus_framefmt *mbus_format =
+		v4l2_subdev_get_try_format(subdev, state, pad);
+	struct mutex *lock = &csi_dev->bridge.lock;
+
+	mutex_lock(lock);
+
+	mbus_format->code = sun6i_csi_bridge_mbus_codes[0];
+	mbus_format->width = 1280;
+	mbus_format->height = 720;
+
+	sun6i_csi_bridge_mbus_format_prepare(mbus_format);
+
+	mutex_unlock(lock);
+
+	return 0;
+}
+
+static int
+sun6i_csi_bridge_enum_mbus_code(struct v4l2_subdev *subdev,
+				struct v4l2_subdev_state *state,
+				struct v4l2_subdev_mbus_code_enum *code_enum)
+{
+	if (code_enum->index >= ARRAY_SIZE(sun6i_csi_bridge_mbus_codes))
+		return -EINVAL;
+
+	code_enum->code = sun6i_csi_bridge_mbus_codes[code_enum->index];
+
+	return 0;
+}
+
+static int sun6i_csi_bridge_get_fmt(struct v4l2_subdev *subdev,
+				    struct v4l2_subdev_state *state,
+				    struct v4l2_subdev_format *format)
+{
+	struct sun6i_csi_device *csi_dev = v4l2_get_subdevdata(subdev);
+	struct v4l2_mbus_framefmt *mbus_format = &format->format;
+	struct mutex *lock = &csi_dev->bridge.lock;
+
+	mutex_lock(lock);
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
+		*mbus_format = *v4l2_subdev_get_try_format(subdev, state,
+							   format->pad);
+	else
+		*mbus_format = csi_dev->bridge.mbus_format;
+
+	mutex_unlock(lock);
+
+	return 0;
+}
+
+static int sun6i_csi_bridge_set_fmt(struct v4l2_subdev *subdev,
+				    struct v4l2_subdev_state *state,
+				    struct v4l2_subdev_format *format)
+{
+	struct sun6i_csi_device *csi_dev = v4l2_get_subdevdata(subdev);
+	struct v4l2_mbus_framefmt *mbus_format = &format->format;
+	struct mutex *lock = &csi_dev->bridge.lock;
+
+	mutex_lock(lock);
+
+	sun6i_csi_bridge_mbus_format_prepare(mbus_format);
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
+		*v4l2_subdev_get_try_format(subdev, state, format->pad) =
+			*mbus_format;
+	else
+		csi_dev->bridge.mbus_format = *mbus_format;
+
+	mutex_unlock(lock);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops sun6i_csi_bridge_pad_ops = {
+	.init_cfg	= sun6i_csi_bridge_init_cfg,
+	.enum_mbus_code	= sun6i_csi_bridge_enum_mbus_code,
+	.get_fmt	= sun6i_csi_bridge_get_fmt,
+	.set_fmt	= sun6i_csi_bridge_set_fmt,
+};
+
+const struct v4l2_subdev_ops sun6i_csi_bridge_subdev_ops = {
+	.video	= &sun6i_csi_bridge_video_ops,
+	.pad	= &sun6i_csi_bridge_pad_ops,
+};
+
+/* Media Entity */
+
+static const struct media_entity_operations sun6i_csi_bridge_entity_ops = {
+	.link_validate	= v4l2_subdev_link_validate,
+};
+
+/* V4L2 Async */
+
+static int sun6i_csi_bridge_link(struct sun6i_csi_device *csi_dev,
+				 int sink_pad_index,
+				 struct v4l2_subdev *remote_subdev,
+				 bool enabled)
+{
+	struct device *dev = csi_dev->dev;
+	struct v4l2_subdev *subdev = &csi_dev->bridge.subdev;
+	struct media_entity *sink_entity = &subdev->entity;
+	struct media_entity *source_entity = &remote_subdev->entity;
+	int source_pad_index;
+	int ret;
+
+	/* Get the first remote source pad. */
+	ret = media_entity_get_fwnode_pad(source_entity, remote_subdev->fwnode,
+					  MEDIA_PAD_FL_SOURCE);
+	if (ret < 0) {
+		dev_err(dev, "missing source pad in external entity %s\n",
+			source_entity->name);
+		return -EINVAL;
+	}
+
+	source_pad_index = ret;
+
+	dev_dbg(dev, "creating %s:%u -> %s:%u link\n", source_entity->name,
+		source_pad_index, sink_entity->name, sink_pad_index);
+
+	ret = media_create_pad_link(source_entity, source_pad_index,
+				    sink_entity, sink_pad_index,
+				    enabled ? MEDIA_LNK_FL_ENABLED : 0);
+	if (ret < 0) {
+		dev_err(dev, "failed to create %s:%u -> %s:%u link\n",
+			source_entity->name, source_pad_index,
+			sink_entity->name, sink_pad_index);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int
+sun6i_csi_bridge_notifier_bound(struct v4l2_async_notifier *notifier,
+				struct v4l2_subdev *remote_subdev,
+				struct v4l2_async_subdev *async_subdev)
+{
+	struct sun6i_csi_device *csi_dev =
+		container_of(notifier, struct sun6i_csi_device,
+			     bridge.notifier);
+	struct sun6i_csi_bridge_async_subdev *bridge_async_subdev =
+		container_of(async_subdev, struct sun6i_csi_bridge_async_subdev,
+			     async_subdev);
+	struct sun6i_csi_bridge_source *source = bridge_async_subdev->source;
+	bool enabled;
+
+	switch (source->endpoint.base.port) {
+	case SUN6I_CSI_PORT_PARALLEL:
+		enabled = true;
+		break;
+	default:
+		break;
+	}
+
+	source->subdev = remote_subdev;
+
+	return sun6i_csi_bridge_link(csi_dev, SUN6I_CSI_BRIDGE_PAD_SINK,
+				     remote_subdev, enabled);
+}
+
+static int
+sun6i_csi_bridge_notifier_complete(struct v4l2_async_notifier *notifier)
+{
+	struct sun6i_csi_device *csi_dev =
+		container_of(notifier, struct sun6i_csi_device,
+			     bridge.notifier);
+	struct v4l2_device *v4l2_dev = &csi_dev->v4l2.v4l2_dev;
+
+	return v4l2_device_register_subdev_nodes(v4l2_dev);
+}
+
+static const struct v4l2_async_notifier_operations
+sun6i_csi_bridge_notifier_ops = {
+	.bound		= sun6i_csi_bridge_notifier_bound,
+	.complete	= sun6i_csi_bridge_notifier_complete,
+};
+
+/* Bridge */
+
+static int sun6i_csi_bridge_source_setup(struct sun6i_csi_device *csi_dev,
+					 struct sun6i_csi_bridge_source *source,
+					 u32 port,
+					 enum v4l2_mbus_type *bus_types)
+{
+	struct device *dev = csi_dev->dev;
+	struct v4l2_async_notifier *notifier = &csi_dev->bridge.notifier;
+	struct v4l2_fwnode_endpoint *endpoint = &source->endpoint;
+	struct sun6i_csi_bridge_async_subdev *bridge_async_subdev;
+	struct fwnode_handle *handle;
+	int ret;
+
+	handle = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), port, 0, 0);
+	if (!handle)
+		return -ENODEV;
+
+	ret = v4l2_fwnode_endpoint_parse(handle, endpoint);
+	if (ret)
+		goto complete;
+
+	if (bus_types) {
+		bool valid = false;
+		unsigned int i;
+
+		for (i = 0; bus_types[i] != V4L2_MBUS_INVALID; i++) {
+			if (endpoint->bus_type == bus_types[i]) {
+				valid = true;
+				break;
+			}
+		}
+
+		if (!valid) {
+			dev_err(dev, "unsupported bus type for port %d\n",
+				port);
+			ret = -EINVAL;
+			goto complete;
+		}
+	}
+
+	bridge_async_subdev =
+		v4l2_async_nf_add_fwnode_remote(notifier, handle,
+						struct
+						sun6i_csi_bridge_async_subdev);
+	if (IS_ERR(bridge_async_subdev)) {
+		ret = PTR_ERR(bridge_async_subdev);
+		goto complete;
+	}
+
+	bridge_async_subdev->source = source;
+
+	source->expected = true;
+
+complete:
+	fwnode_handle_put(handle);
+
+	return ret;
+}
+
+int sun6i_csi_bridge_setup(struct sun6i_csi_device *csi_dev)
+{
+	struct device *dev = csi_dev->dev;
+	struct sun6i_csi_bridge *bridge = &csi_dev->bridge;
+	struct v4l2_device *v4l2_dev = &csi_dev->v4l2.v4l2_dev;
+	struct v4l2_subdev *subdev = &bridge->subdev;
+	struct v4l2_async_notifier *notifier = &bridge->notifier;
+	struct media_pad *pads = bridge->pads;
+	enum v4l2_mbus_type parallel_mbus_types[] = {
+		V4L2_MBUS_PARALLEL,
+		V4L2_MBUS_BT656,
+		V4L2_MBUS_INVALID
+	};
+	int ret;
+
+	mutex_init(&bridge->lock);
+
+	/* V4L2 Subdev */
+
+	v4l2_subdev_init(subdev, &sun6i_csi_bridge_subdev_ops);
+	strscpy(subdev->name, SUN6I_CSI_BRIDGE_NAME, sizeof(subdev->name));
+	subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	subdev->owner = THIS_MODULE;
+	subdev->dev = dev;
+
+	v4l2_set_subdevdata(subdev, csi_dev);
+
+	/* Media Entity */
+
+	subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	subdev->entity.ops = &sun6i_csi_bridge_entity_ops;
+
+	/* Media Pads */
+
+	pads[SUN6I_CSI_BRIDGE_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+	pads[SUN6I_CSI_BRIDGE_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE |
+						  MEDIA_PAD_FL_MUST_CONNECT;
+
+	ret = media_entity_pads_init(&subdev->entity,
+				     SUN6I_CSI_BRIDGE_PAD_COUNT, pads);
+	if (ret < 0)
+		return ret;
+
+	/* V4L2 Subdev */
+
+	ret = v4l2_device_register_subdev(v4l2_dev, subdev);
+	if (ret) {
+		dev_err(dev, "failed to register v4l2 subdev: %d\n", ret);
+		goto error_media_entity;
+	}
+
+	/* V4L2 Async */
+
+	v4l2_async_nf_init(notifier);
+	notifier->ops = &sun6i_csi_bridge_notifier_ops;
+
+	sun6i_csi_bridge_source_setup(csi_dev, &bridge->source_parallel,
+				      SUN6I_CSI_PORT_PARALLEL,
+				      parallel_mbus_types);
+
+	ret = v4l2_async_nf_register(v4l2_dev, notifier);
+	if (ret) {
+		dev_err(dev, "failed to register v4l2 async notifier: %d\n",
+			ret);
+		goto error_v4l2_async_notifier;
+	}
+
+	return 0;
+
+error_v4l2_async_notifier:
+	v4l2_async_nf_cleanup(notifier);
+
+	v4l2_device_unregister_subdev(subdev);
+
+error_media_entity:
+	media_entity_cleanup(&subdev->entity);
+
+	return ret;
+}
+
+void sun6i_csi_bridge_cleanup(struct sun6i_csi_device *csi_dev)
+{
+	struct v4l2_subdev *subdev = &csi_dev->bridge.subdev;
+	struct v4l2_async_notifier *notifier = &csi_dev->bridge.notifier;
+
+	v4l2_async_nf_unregister(notifier);
+	v4l2_async_nf_cleanup(notifier);
+
+	v4l2_device_unregister_subdev(subdev);
+
+	media_entity_cleanup(&subdev->entity);
+}
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.h
new file mode 100644
index 000000000000..f9bf87bf3667
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.h
@@ -0,0 +1,49 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2021-2022 Bootlin
+ * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+ */
+
+#ifndef _SUN6I_CSI_BRIDGE_H_
+#define _SUN6I_CSI_BRIDGE_H_
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+
+#define SUN6I_CSI_BRIDGE_NAME	"sun6i-csi-bridge"
+
+enum sun6i_csi_bridge_pad {
+	SUN6I_CSI_BRIDGE_PAD_SINK	= 0,
+	SUN6I_CSI_BRIDGE_PAD_SOURCE	= 1,
+	SUN6I_CSI_BRIDGE_PAD_COUNT	= 2,
+};
+
+struct sun6i_csi_device;
+
+struct sun6i_csi_bridge_source {
+	struct v4l2_subdev		*subdev;
+	struct v4l2_fwnode_endpoint	endpoint;
+	bool				expected;
+};
+
+struct sun6i_csi_bridge_async_subdev {
+	struct v4l2_async_subdev	async_subdev;
+	struct sun6i_csi_bridge_source	*source;
+};
+
+struct sun6i_csi_bridge {
+	struct v4l2_subdev		subdev;
+	struct v4l2_async_notifier	notifier;
+	struct media_pad		pads[2];
+	struct v4l2_mbus_framefmt	mbus_format;
+	struct mutex			lock; /* Mbus format lock. */
+
+	struct sun6i_csi_bridge_source	source_parallel;
+};
+
+/* Bridge */
+
+int sun6i_csi_bridge_setup(struct sun6i_csi_device *csi_dev);
+void sun6i_csi_bridge_cleanup(struct sun6i_csi_device *csi_dev);
+
+#endif
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
index 791583d23a65..fa83211a2c5a 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
@@ -632,6 +632,7 @@  int sun6i_video_setup(struct sun6i_csi_device *csi_dev)
 {
 	struct sun6i_video *video = &csi_dev->video;
 	struct v4l2_device *v4l2_dev = &csi_dev->v4l2.v4l2_dev;
+	struct v4l2_subdev *bridge_subdev = &csi_dev->bridge.subdev;
 	struct video_device *video_dev = &video->video_dev;
 	struct vb2_queue *queue = &video->queue;
 	struct media_pad *pad = &video->pad;
@@ -712,8 +713,26 @@  int sun6i_video_setup(struct sun6i_csi_device *csi_dev)
 		goto error_media_entity;
 	}
 
+	/* Media Pad Link */
+
+	ret = media_create_pad_link(&bridge_subdev->entity,
+				    SUN6I_CSI_BRIDGE_PAD_SOURCE,
+				    &video_dev->entity, 0,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+	if (ret < 0) {
+		v4l2_err(v4l2_dev, "failed to create %s:%u -> %s:%u link\n",
+			 bridge_subdev->entity.name,
+			 SUN6I_CSI_BRIDGE_PAD_SOURCE,
+			 video_dev->entity.name, 0);
+		goto error_video_device;
+	}
+
 	return 0;
 
+error_video_device:
+	vb2_video_unregister_device(video_dev);
+
 error_media_entity:
 	media_entity_cleanup(&video_dev->entity);