Commit be2fff65 authored by Ezequiel Garcia's avatar Ezequiel Garcia Committed by Mauro Carvalho Chehab
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media: add helpers for memory-to-memory media controller 



A memory-to-memory pipeline device consists in three
entities: two DMA engine and one video processing entities.
The DMA engine entities are linked to a V4L interface.

This commit add a new v4l2_m2m_{un}register_media_controller
API to register this topology.

For instance, a typical mem2mem device topology would
look like this:

Device topology
- entity 1: source (1 pad, 1 link)
            type Node subtype V4L flags 0
	pad0: Source
		-> "proc":1 [ENABLED,IMMUTABLE]

- entity 3: proc (2 pads, 2 links)
            type Node subtype Unknown flags 0
	pad0: Source
		-> "sink":0 [ENABLED,IMMUTABLE]
	pad1: Sink
		<- "source":0 [ENABLED,IMMUTABLE]

- entity 6: sink (1 pad, 1 link)
            type Node subtype V4L flags 0
	pad0: Sink
		<- "proc":0 [ENABLED,IMMUTABLE]

[hans.verkuil@cisco.com: mark interface links as IMMUTABLE]

Suggested-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarEzequiel Garcia <ezequiel@collabora.com>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 4d1e4545

drivers/media/v4l2-core/v4l2-dev.c

+8 −5
Original line number Diff line number Diff line
@@ -202,7 +202,7 @@ static void v4l2_device_release(struct device *cd) 
	mutex_unlock(&videodev_lock);



#if defined(CONFIG_MEDIA_CONTROLLER)

	if (v4l2_dev->mdev) {

	if (v4l2_dev->mdev && vdev->vfl_dir != VFL_DIR_M2M) {

		/* Remove interfaces and interface links */

		media_devnode_remove(vdev->intf_devnode);

		if (vdev->entity.function != MEDIA_ENT_F_UNKNOWN)
@@ -733,19 +733,22 @@ static void determine_valid_ioctls(struct video_device *vdev) 
			BASE_VIDIOC_PRIVATE);

}



static int video_register_media_controller(struct video_device *vdev, int type)

static int video_register_media_controller(struct video_device *vdev)

{

#if defined(CONFIG_MEDIA_CONTROLLER)

	u32 intf_type;

	int ret;



	if (!vdev->v4l2_dev->mdev)

	/* Memory-to-memory devices are more complex and use

	 * their own function to register its mc entities.

	 */

	if (!vdev->v4l2_dev->mdev || vdev->vfl_dir == VFL_DIR_M2M)

		return 0;



	vdev->entity.obj_type = MEDIA_ENTITY_TYPE_VIDEO_DEVICE;

	vdev->entity.function = MEDIA_ENT_F_UNKNOWN;



	switch (type) {

	switch (vdev->vfl_type) {

	case VFL_TYPE_GRABBER:

		intf_type = MEDIA_INTF_T_V4L_VIDEO;

		vdev->entity.function = MEDIA_ENT_F_IO_V4L;
@@ -994,7 +997,7 @@ int __video_register_device(struct video_device *vdev, 
	v4l2_device_get(vdev->v4l2_dev);



	/* Part 5: Register the entity. */

	ret = video_register_media_controller(vdev, type);

	ret = video_register_media_controller(vdev);



	/* Part 6: Activate this minor. The char device can now be used. */

	set_bit(V4L2_FL_REGISTERED, &vdev->flags);

drivers/media/v4l2-core/v4l2-mem2mem.c

+190 −0
Original line number Diff line number Diff line
@@ -17,9 +17,11 @@ 
#include <linux/sched.h>

#include <linux/slab.h>



#include <media/media-device.h>

#include <media/videobuf2-v4l2.h>

#include <media/v4l2-mem2mem.h>

#include <media/v4l2-dev.h>

#include <media/v4l2-device.h>

#include <media/v4l2-fh.h>

#include <media/v4l2-event.h>
@@ -50,6 +52,17 @@ module_param(debug, bool, 0644); 
 * offsets but for different queues */

#define DST_QUEUE_OFF_BASE	(1 << 30)



enum v4l2_m2m_entity_type {

	MEM2MEM_ENT_TYPE_SOURCE,

	MEM2MEM_ENT_TYPE_SINK,

	MEM2MEM_ENT_TYPE_PROC

};



static const char * const m2m_entity_name[] = {

	"source",

	"sink",

	"proc"

};



/**

 * struct v4l2_m2m_dev - per-device context
@@ -60,6 +73,15 @@ module_param(debug, bool, 0644); 
 */

struct v4l2_m2m_dev {

	struct v4l2_m2m_ctx	*curr_ctx;

#ifdef CONFIG_MEDIA_CONTROLLER

	struct media_entity	*source;

	struct media_pad	source_pad;

	struct media_entity	sink;

	struct media_pad	sink_pad;

	struct media_entity	proc;

	struct media_pad	proc_pads[2];

	struct media_intf_devnode *intf_devnode;

#endif



	struct list_head	job_queue;

	spinlock_t		job_spinlock;
@@ -594,6 +616,174 @@ int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 
}

EXPORT_SYMBOL(v4l2_m2m_mmap);



#if defined(CONFIG_MEDIA_CONTROLLER)

void v4l2_m2m_unregister_media_controller(struct v4l2_m2m_dev *m2m_dev)

{

	media_remove_intf_links(&m2m_dev->intf_devnode->intf);

	media_devnode_remove(m2m_dev->intf_devnode);



	media_entity_remove_links(m2m_dev->source);

	media_entity_remove_links(&m2m_dev->sink);

	media_entity_remove_links(&m2m_dev->proc);

	media_device_unregister_entity(m2m_dev->source);

	media_device_unregister_entity(&m2m_dev->sink);

	media_device_unregister_entity(&m2m_dev->proc);

	kfree(m2m_dev->source->name);

	kfree(m2m_dev->sink.name);

	kfree(m2m_dev->proc.name);

}

EXPORT_SYMBOL_GPL(v4l2_m2m_unregister_media_controller);



static int v4l2_m2m_register_entity(struct media_device *mdev,

	struct v4l2_m2m_dev *m2m_dev, enum v4l2_m2m_entity_type type,

	struct video_device *vdev, int function)

{

	struct media_entity *entity;

	struct media_pad *pads;

	char *name;

	unsigned int len;

	int num_pads;

	int ret;



	switch (type) {

	case MEM2MEM_ENT_TYPE_SOURCE:

		entity = m2m_dev->source;

		pads = &m2m_dev->source_pad;

		pads[0].flags = MEDIA_PAD_FL_SOURCE;

		num_pads = 1;

		break;

	case MEM2MEM_ENT_TYPE_SINK:

		entity = &m2m_dev->sink;

		pads = &m2m_dev->sink_pad;

		pads[0].flags = MEDIA_PAD_FL_SINK;

		num_pads = 1;

		break;

	case MEM2MEM_ENT_TYPE_PROC:

		entity = &m2m_dev->proc;

		pads = m2m_dev->proc_pads;

		pads[0].flags = MEDIA_PAD_FL_SINK;

		pads[1].flags = MEDIA_PAD_FL_SOURCE;

		num_pads = 2;

		break;

	default:

		return -EINVAL;

	}



	entity->obj_type = MEDIA_ENTITY_TYPE_BASE;

	if (type != MEM2MEM_ENT_TYPE_PROC) {

		entity->info.dev.major = VIDEO_MAJOR;

		entity->info.dev.minor = vdev->minor;

	}

	len = strlen(vdev->name) + 2 + strlen(m2m_entity_name[type]);

	name = kmalloc(len, GFP_KERNEL);

	if (!name)

		return -ENOMEM;

	snprintf(name, len, "%s-%s", vdev->name, m2m_entity_name[type]);

	entity->name = name;

	entity->function = function;



	ret = media_entity_pads_init(entity, num_pads, pads);

	if (ret)

		return ret;

	ret = media_device_register_entity(mdev, entity);

	if (ret)

		return ret;



	return 0;

}



int v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev,

		struct video_device *vdev, int function)

{

	struct media_device *mdev = vdev->v4l2_dev->mdev;

	struct media_link *link;

	int ret;



	if (!mdev)

		return 0;



	/* A memory-to-memory device consists in two

	 * DMA engine and one video processing entities.

	 * The DMA engine entities are linked to a V4L interface

	 */



	/* Create the three entities with their pads */

	m2m_dev->source = &vdev->entity;

	ret = v4l2_m2m_register_entity(mdev, m2m_dev,

			MEM2MEM_ENT_TYPE_SOURCE, vdev, MEDIA_ENT_F_IO_V4L);

	if (ret)

		return ret;

	ret = v4l2_m2m_register_entity(mdev, m2m_dev,

			MEM2MEM_ENT_TYPE_PROC, vdev, function);

	if (ret)

		goto err_rel_entity0;

	ret = v4l2_m2m_register_entity(mdev, m2m_dev,

			MEM2MEM_ENT_TYPE_SINK, vdev, MEDIA_ENT_F_IO_V4L);

	if (ret)

		goto err_rel_entity1;



	/* Connect the three entities */

	ret = media_create_pad_link(m2m_dev->source, 0, &m2m_dev->proc, 1,

			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);

	if (ret)

		goto err_rel_entity2;



	ret = media_create_pad_link(&m2m_dev->proc, 0, &m2m_dev->sink, 0,

			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);

	if (ret)

		goto err_rm_links0;



	/* Create video interface */

	m2m_dev->intf_devnode = media_devnode_create(mdev,

			MEDIA_INTF_T_V4L_VIDEO, 0,

			VIDEO_MAJOR, vdev->minor);

	if (!m2m_dev->intf_devnode) {

		ret = -ENOMEM;

		goto err_rm_links1;

	}



	/* Connect the two DMA engines to the interface */

	link = media_create_intf_link(m2m_dev->source,

			&m2m_dev->intf_devnode->intf,

			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);

	if (!link) {

		ret = -ENOMEM;

		goto err_rm_devnode;

	}



	link = media_create_intf_link(&m2m_dev->sink,

			&m2m_dev->intf_devnode->intf,

			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);

	if (!link) {

		ret = -ENOMEM;

		goto err_rm_intf_link;

	}

	return 0;



err_rm_intf_link:

	media_remove_intf_links(&m2m_dev->intf_devnode->intf);

err_rm_devnode:

	media_devnode_remove(m2m_dev->intf_devnode);

err_rm_links1:

	media_entity_remove_links(&m2m_dev->sink);

err_rm_links0:

	media_entity_remove_links(&m2m_dev->proc);

	media_entity_remove_links(m2m_dev->source);

err_rel_entity2:

	media_device_unregister_entity(&m2m_dev->proc);

	kfree(m2m_dev->proc.name);

err_rel_entity1:

	media_device_unregister_entity(&m2m_dev->sink);

	kfree(m2m_dev->sink.name);

err_rel_entity0:

	media_device_unregister_entity(m2m_dev->source);

	kfree(m2m_dev->source->name);

	return ret;

	return 0;

}

EXPORT_SYMBOL_GPL(v4l2_m2m_register_media_controller);

#endif



struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)

{

	struct v4l2_m2m_dev *m2m_dev;

include/media/v4l2-mem2mem.h

+19 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ struct v4l2_m2m_ops { 
	void (*job_abort)(void *priv);

};



struct video_device;

struct v4l2_m2m_dev;



/**
@@ -322,6 +323,24 @@ int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 
 */

struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops);



#if defined(CONFIG_MEDIA_CONTROLLER)

void v4l2_m2m_unregister_media_controller(struct v4l2_m2m_dev *m2m_dev);

int v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev,

			struct video_device *vdev, int function);

#else

static inline void

v4l2_m2m_unregister_media_controller(struct v4l2_m2m_dev *m2m_dev)

{

}



static inline int

v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev,

		struct video_device *vdev, int function)

{

	return 0;

}

#endif



/**

 * v4l2_m2m_release() - cleans up and frees a m2m_dev structure

 *

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