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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Ezequiel Garcia 2018-07-02 11:36:05 -04:00 committed by Mauro Carvalho Chehab
parent 4d1e4545a6
commit be2fff6563
3 changed files with 217 additions and 5 deletions

View File

@ -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);

View File

@ -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;

View File

@ -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
*