media: entity: Add support for ancillary links

Add functions to create ancillary links, so that they don't need to
be manually created by users.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>

diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 29d1285..7bf2c73 100644 (file)
--- 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 09737b4..72c7cd8 100644 (file)
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -1107,4 +1107,23 @@ void media_remove_intf_links(struct media_interface *intf);
        (((entity)->ops && (entity)->ops->operation) ?                  \
         (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
 
+/**
+ * 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 controller 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.
+ */
+struct media_link *
+media_create_ancillary_link(struct media_entity *primary,
+                           struct media_entity *ancillary);
+
 #endif