[PATCH v5 12/24] media: entity: Add an iterator helper for connected pads

[Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>]

From: Sakari Ailus <sakari.ailus@linux.intel.com>

Add a helper macro for iterating over pads that are connected through
enabled routes. This can be used to find all the connected pads within an
entity, for instance starting from the pad which has been obtained during
the graph walk.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

- Make __media_entity_next_routed_pad() return NULL and adjust the
  iterator to handle that
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 include/media/media-entity.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 73de1c335e4e..edd6f60ed6b4 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -916,6 +916,33 @@ __must_check int media_graph_walk_init(
 bool media_entity_has_route(struct media_entity *entity, unsigned int pad0,
 			    unsigned int pad1);
 
+static inline struct media_pad *__media_entity_next_routed_pad(
+	struct media_pad *start, struct media_pad *iter)
+{
+	struct media_entity *entity = start->entity;
+
+	for (; iter < &entity->pads[entity->num_pads]; iter++)
+		if (media_entity_has_route(entity, start->index, iter->index))
+			return iter;
+
+	return NULL;
+}
+
+/**
+ * media_entity_for_each_routed_pad - Iterate over entity pads connected by routes
+ *
+ * @start: The stating pad
+ * @iter: The iterator pad
+ *
+ * Iterate over all pads connected through routes from a given pad
+ * within an entity. The iteration will include the starting pad itself.
+ */
+#define media_entity_for_each_routed_pad(start, iter)			\
+	for (iter = __media_entity_next_routed_pad(			\
+		     start, (start)->entity->pads);			\
+	     iter != NULL;						\
+	     iter = __media_entity_next_routed_pad(start, iter + 1))
+
 /**
  * media_graph_walk_cleanup - Release resources used by graph walk.
  *
-- 
2.25.1