Add functions to create ancillary links, so that they don't need to
be manually created by users.
Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
---
Changes since v1:
- Hardcoded MEDIA_LINK_FL_IMMUTABLE and MEDIA_LINK_FL_ENABLED (Laurent)
Changes since the rfc:
- (Laurent) Set gobj0 and gobj1 directly instead of the other union
members
- (Laurent) Added MEDIA_LNK_FL_IMMUTABLE to the kerneldoc for the new
create function
drivers/media/mc/mc-entity.c | 22 ++++++++++++++++++++++
include/media/media-entity.h | 21 +++++++++++++++++++++
2 files changed, 43 insertions(+)
diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 29d1285c805a..7bf2c73a3886 100644
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -1050,3 +1050,25 @@ void media_remove_intf_links(struct media_interface *intf)
mutex_unlock(&mdev->graph_mutex);
}
EXPORT_SYMBOL_GPL(media_remove_intf_links);
+
+struct media_link *media_create_ancillary_link(struct media_entity *primary,
+ struct media_entity *ancillary)
+{
+ struct media_link *link;
+
+ link = media_add_link(&primary->links);
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+
+ link->gobj0 = &primary->graph_obj;
+ link->gobj1 = &ancillary->graph_obj;
+ link->flags = MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED |
+ MEDIA_LNK_FL_ANCILLARY_LINK;
+
+ /* Initialize graph object embedded in the new link */
+ media_gobj_create(primary->graph_obj.mdev, MEDIA_GRAPH_LINK,
+ &link->graph_obj);
+
+ return link;
+}
+EXPORT_SYMBOL_GPL(media_create_ancillary_link);
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index fea489f03d57..afeda41ece4c 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -1104,6 +1104,27 @@ void media_remove_intf_links(struct media_interface *intf);
* it will issue a call to @operation\(@entity, @args\).
*/
+/**
+ * media_create_ancillary_link() - create an ancillary link between two
+ * instances of &media_entity
+ *
+ * @primary: pointer to the primary &media_entity
+ * @ancillary: pointer to the ancillary &media_entity
+ *
+ * Create an ancillary link between two entities, indicating that they
+ * represent two connected pieces of hardware that form a single logical unit.
+ * A typical example is a camera lens being linked to the sensor that it is
+ * supporting.
+ *
+ * The function sets both MEDIA_LNK_FL_ENABLED and MEDIA_LNK_FL_IMMUTABLE for
+ * the new link. This behaviour may be subject to change in the future, so
+ * userspace applications using ancillary links should ensure that ancillary
+ * links are enabled when in use.
+ */
+struct media_link *
+media_create_ancillary_link(struct media_entity *primary,
+ struct media_entity *ancillary);
+
#define media_entity_call(entity, operation, args...) \
(((entity)->ops && (entity)->ops->operation) ? \
(entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
--
2.25.1
