media: entity: Add iterator for entity data links

Iterating over the links for an entity is a somewhat common need
through the media subsystem, but generally the assumption is that
they will all be data links. To meet that assumption add a new macro
that iterates through an entity's links and skips non-data links.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This commit is contained in:
Daniel Scally 2022-07-07 23:47:32 +01:00 committed by Mauro Carvalho Chehab
parent 3193ceeae4
commit 1ed3d6446b
2 changed files with 46 additions and 0 deletions

View file

@ -9,6 +9,7 @@
*/
#include <linux/bitmap.h>
#include <linux/list.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <media/media-entity.h>
@ -1051,3 +1052,18 @@ struct media_link *media_create_ancillary_link(struct media_entity *primary,
return link;
}
EXPORT_SYMBOL_GPL(media_create_ancillary_link);
struct media_link *__media_entity_next_link(struct media_entity *entity,
struct media_link *link,
unsigned long link_type)
{
link = link ? list_next_entry(link, list)
: list_first_entry(&entity->links, typeof(*link), list);
list_for_each_entry_from(link, &entity->links, list)
if ((link->flags & MEDIA_LNK_FL_LINK_TYPE) == link_type)
return link;
return NULL;
}
EXPORT_SYMBOL_GPL(__media_entity_next_link);

View file

@ -1140,4 +1140,34 @@ struct media_link *
media_create_ancillary_link(struct media_entity *primary,
struct media_entity *ancillary);
/**
* __media_entity_next_link() - Iterate through a &media_entity's links
*
* @entity: pointer to the &media_entity
* @link: pointer to a &media_link to hold the iterated values
* @link_type: one of the MEDIA_LNK_FL_LINK_TYPE flags
*
* Return the next link against an entity matching a specific link type. This
* allows iteration through an entity's links whilst guaranteeing all of the
* returned links are of the given type.
*/
struct media_link *__media_entity_next_link(struct media_entity *entity,
struct media_link *link,
unsigned long link_type);
/**
* for_each_media_entity_data_link() - Iterate through an entity's data links
*
* @entity: pointer to the &media_entity
* @link: pointer to a &media_link to hold the iterated values
*
* Iterate over a &media_entity's data links
*/
#define for_each_media_entity_data_link(entity, link) \
for (link = __media_entity_next_link(entity, NULL, \
MEDIA_LNK_FL_DATA_LINK); \
link; \
link = __media_entity_next_link(entity, link, \
MEDIA_LNK_FL_DATA_LINK))
#endif