On 08/07/15 16:20, Mauro Carvalho Chehab wrote:
> Interfaces are different than entities: they represent a
> Kernel<->userspace interaction, while entities represent a
> piece of hardware/firmware/software that executes a function.
>
> Let's distinguish them by creating a separate structure to
> store the interfaces.
>
> Latter patches should change the existing drivers and logic
> to split the current interface embedded inside the entity
> structure (device nodes) into a separate object of the graph.
So, to be clear, the plan is to replace the embedded media_entity
struct in struct video_device by a struct media_intf_devnode pointer
that is allocated with media_devnode_create()?
Can we keep struct media_intf_devnode embedded in struct video_device?
Or is that impossible since all media_graph_obj structs are expected
to be allocated?
I do have a preference for keeping structs embedded, unless there is a
good reason not to. I just want to make sure there is a good reason.
Regards,
Hans
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
>
> diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
> index 5c0d197fa072..bc806958815e 100644
> --- a/drivers/media/media-entity.c
> +++ b/drivers/media/media-entity.c
> @@ -741,3 +741,59 @@ struct media_pad *media_entity_remote_pad(struct media_pad *pad)
>
> }
> EXPORT_SYMBOL_GPL(media_entity_remote_pad);
> +
> +
> +/* Functions related to the media interface via device nodes */
> +
> +struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
> + u32 major, u32 minor,
> + gfp_t gfp_flags)
> +{
> + struct media_intf_devnode *devnode;
> +
> + devnode = kzalloc(sizeof(*devnode), gfp_flags);
> + if (!devnode)
> + return NULL;
> +
> + devnode->major = major;
> + devnode->minor = minor;
> + INIT_LIST_HEAD(&devnode->intf.entity_links);
> +
> + graph_obj_init(mdev, MEDIA_GRAPH_INTF_DEVNODE,
> + &devnode->intf.graph_obj);
> +
> + return devnode;
> +}
> +EXPORT_SYMBOL_GPL(media_devnode_create);
> +
> +void media_devnode_remove(struct media_intf_devnode *devnode)
> +{
> + graph_obj_remove(&devnode->intf.graph_obj);
> + kfree(devnode);
> +}
> +EXPORT_SYMBOL_GPL(media_devnode_remove);
> +
> +struct media_link *media_create_intf_link(struct media_entity *entity,
> + struct media_graph_obj *gobj,
> + u32 flags)
> +{
> + struct media_link *link;
> +
> + /* Only accept links between entity<==>interface */
> + if (gobj->type != MEDIA_GRAPH_INTF_DEVNODE)
> + return NULL;
> +
> + link = __media_create_link(entity->parent,
> + MEDIA_LINK_DIR_BIDIRECTIONAL,
> + &entity->graph_obj,
> + gobj,
> + flags, &entity->intf_links);
> + if (link == NULL)
> + return NULL;
> +
> + /* Create the link at the interface */
> + list_add(&gobj_to_interface(gobj)->entity_links, &link->list);
> +
> + return link;
> +}
> +EXPORT_SYMBOL_GPL(media_create_intf_link);
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index 5f080ab88399..1faeb74f8489 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -36,11 +36,14 @@
> * @MEDIA_GRAPH_ENTITY: Identify a media entity
> * @MEDIA_GRAPH_PAD: Identify a media PAD
> * @MEDIA_GRAPH_LINK: Identify a media link
> + * @MEDIA_GRAPH_INTF_DEVNODE: Identify a media Kernel API interface via
> + * a device node
> */
> enum media_graph_type {
> MEDIA_GRAPH_ENTITY,
> MEDIA_GRAPH_PAD,
> MEDIA_GRAPH_LINK,
> + MEDIA_GRAPH_INTF_DEVNODE,
> };
>
> /**
> @@ -136,7 +139,9 @@ struct media_entity {
> u16 num_backlinks; /* Number of backlinks */
>
> struct media_pad *pads; /* Pads array (num_pads elements) */
> - struct list_head links; /* Links list */
> + struct list_head links; /* PAD links list */
> +
> + struct list_head intf_links; /* Interface links list */
>
> const struct media_entity_operations *ops; /* Entity operations */
>
> @@ -161,6 +166,30 @@ struct media_entity {
> } info;
> };
>
> +/**
> + * struct media_intf_devnode - Define a Kernel API interface
> + *
> + * @graph_obj: embedded graph object
> + * @ent_links: List of links pointing to graph entities
> + */
> +struct media_interface {
> + struct media_graph_obj graph_obj;
> + struct list_head entity_links;
> +};
> +
> +/**
> + * struct media_intf_devnode - Define a Kernel API interface via a device node
> + *
> + * @intf: embedded interface object
> + * @major: Major number of a device node
> + * @minor: Minor number of a device node
> + */
> +struct media_intf_devnode {
> + struct media_interface intf;
> + u32 major;
> + u32 minor;
> +};
> +
> static inline u32 media_entity_type(struct media_entity *entity)
> {
> return entity->type & MEDIA_ENT_TYPE_MASK;
> @@ -193,6 +222,9 @@ struct media_entity_graph {
> #define gobj_to_pad(gobj) \
> container_of(gobj, struct media_pad, graph_obj)
>
> +#define gobj_to_interface(gobj) \
> + container_of(gobj, struct media_interface, graph_obj)
> +
> void graph_obj_init(struct media_device *mdev,
> enum media_graph_type type,
> struct media_graph_obj *gobj);
> @@ -224,6 +256,14 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
> struct media_pipeline *pipe);
> void media_entity_pipeline_stop(struct media_entity *entity);
>
> +struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
> + u32 major, u32 minor,
> + gfp_t gfp_flags);
> +void media_devnode_remove(struct media_intf_devnode *devnode);
> +struct media_link *media_create_intf_link(struct media_entity *entity,
> + struct media_graph_obj *gobj,
> + u32 flags);
> +
> #define media_entity_call(entity, operation, args...) \
> (((entity)->ops && (entity)->ops->operation) ? \
> (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
>
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