From b01cc9ce7c13e0463575332dfa3171727f706afb Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 30 Dec 2015 09:45:48 -0200 Subject: [PATCH] [media] media-entitiy: add a function to create multiple links Sometimes, it is desired to create 1:n and n:1 or even n:n links between different entities with the same function. This is actually needed to support DVB devices that have multiple frontends. While we could do a function like that internally at the DVB core, such function is generic enough to be at media-entity, and it could be useful on some other places. So, add such function. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-entity.c | 65 ++++++++++++++++++++++++++++++++++++ include/media/media-entity.h | 51 ++++++++++++++++++++++++++++ 2 files changed, 116 insertions(+) diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index eb38bc35320a..e89d85a7d31b 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -625,6 +625,71 @@ media_create_pad_link(struct media_entity *source, u16 source_pad, } EXPORT_SYMBOL_GPL(media_create_pad_link); +int media_create_pad_links(const struct media_device *mdev, + const u32 source_function, + struct media_entity *source, + const u16 source_pad, + const u32 sink_function, + struct media_entity *sink, + const u16 sink_pad, + u32 flags, + const bool allow_both_undefined) +{ + struct media_entity *entity; + unsigned function; + int ret; + + /* Trivial case: 1:1 relation */ + if (source && sink) + return media_create_pad_link(source, source_pad, + sink, sink_pad, flags); + + /* Worse case scenario: n:n relation */ + if (!source && !sink) { + if (!allow_both_undefined) + return 0; + media_device_for_each_entity(source, mdev) { + if (source->function != source_function) + continue; + media_device_for_each_entity(sink, mdev) { + if (sink->function != sink_function) + continue; + ret = media_create_pad_link(source, source_pad, + sink, sink_pad, + flags); + if (ret) + return ret; + flags &= ~(MEDIA_LNK_FL_ENABLED | + MEDIA_LNK_FL_IMMUTABLE); + } + } + return 0; + } + + /* Handle 1:n and n:1 cases */ + if (source) + function = sink_function; + else + function = source_function; + + media_device_for_each_entity(entity, mdev) { + if (entity->function != function) + continue; + + if (source) + ret = media_create_pad_link(source, source_pad, + entity, sink_pad, flags); + else + ret = media_create_pad_link(entity, source_pad, + sink, sink_pad, flags); + if (ret) + return ret; + flags &= ~(MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE); + } + return 0; +} +EXPORT_SYMBOL_GPL(media_create_pad_links); + void __media_entity_remove_links(struct media_entity *entity) { struct media_link *link, *tmp; diff --git a/include/media/media-entity.h b/include/media/media-entity.h index 79dd81fd463e..fe485d367985 100644 --- a/include/media/media-entity.h +++ b/include/media/media-entity.h @@ -613,6 +613,57 @@ static inline void media_entity_cleanup(struct media_entity *entity) {}; __must_check int media_create_pad_link(struct media_entity *source, u16 source_pad, struct media_entity *sink, u16 sink_pad, u32 flags); + +/** + * media_create_pad_links() - creates a link between two entities. + * + * @mdev: Pointer to the media_device that contains the object + * @source_function: Function of the source entities. Used only if @source is + * NULL. + * @source: pointer to &media_entity of the source pad. If NULL, it will use + * all entities that matches the @sink_function. + * @source_pad: number of the source pad in the pads array + * @sink_function: Function of the sink entities. Used only if @sink is NULL. + * @sink: pointer to &media_entity of the sink pad. If NULL, it will use + * all entities that matches the @sink_function. + * @sink_pad: number of the sink pad in the pads array. + * @flags: Link flags, as defined in include/uapi/linux/media.h. + * @allow_both_undefined: if true, then both @source and @sink can be NULL. + * In such case, it will create a crossbar between all entities that + * matches @source_function to all entities that matches @sink_function. + * If false, it will return 0 and won't create any link if both @source + * and @sink are NULL. + * + * Valid values for flags: + * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be + * used to transfer media data. If multiple links are created and this + * flag is passed as an argument, only the first created link will have + * this flag. + * + * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't + * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then + * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is + * always enabled. + * + * It is common for some devices to have multiple source and/or sink entities + * of the same type that should be linked. While media_create_pad_link() + * creates link by link, this function is meant to allow 1:n, n:1 and even + * cross-bar (n:n) links. + * + * NOTE: Before calling this function, media_entity_pads_init() and + * media_device_register_entity() should be called previously for the entities + * to be linked. + */ +int media_create_pad_links(const struct media_device *mdev, + const u32 source_function, + struct media_entity *source, + const u16 source_pad, + const u32 sink_function, + struct media_entity *sink, + const u16 sink_pad, + u32 flags, + const bool allow_both_undefined); + void __media_entity_remove_links(struct media_entity *entity); /** -- 2.20.1