From 1ed3d6446b966143e67a106132eea169b3fc5e1c Mon Sep 17 00:00:00 2001 From: Daniel Scally Date: Thu, 7 Jul 2022 23:47:32 +0100 Subject: [PATCH] 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 Reviewed-by: Laurent Pinchart Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/mc/mc-entity.c | 16 ++++++++++++++++ include/media/media-entity.h | 30 ++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c index 11f5207f73aa..a247d5679930 100644 --- a/drivers/media/mc/mc-entity.c +++ b/drivers/media/mc/mc-entity.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -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); diff --git a/include/media/media-entity.h b/include/media/media-entity.h index a9a1c0ec5d1c..4efe2f88e6dc 100644 --- a/include/media/media-entity.h +++ b/include/media/media-entity.h @@ -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