media: mc: entity: Add iterator helper for entity pads

Add an iterator helper to easily cycle through all pads in an entity and
use it in media-entity and media-device code where appropriate.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/mc/mc-device.c

@@ -581,7 +581,7 @@ static void __media_device_unregister_entity(struct media_entity *entity)
 	struct media_device *mdev = entity->graph_obj.mdev;
 	struct media_link *link, *tmp;
 	struct media_interface *intf;
-	unsigned int i;
+	struct media_pad *iter;
 
 	ida_free(&mdev->entity_internal_idx, entity->internal_idx);
 
@@ -597,8 +597,8 @@ static void __media_device_unregister_entity(struct media_entity *entity)
 	__media_entity_remove_links(entity);
 
 	/* Remove all pads that belong to this entity */
-	for (i = 0; i < entity->num_pads; i++)
-		media_gobj_destroy(&entity->pads[i].graph_obj);
+	media_entity_for_each_pad(entity, iter)
+		media_gobj_destroy(&iter->graph_obj);
 
 	/* Remove the entity */
 	media_gobj_destroy(&entity->graph_obj);
@@ -610,7 +610,7 @@ int __must_check media_device_register_entity(struct media_device *mdev,
 					      struct media_entity *entity)
 {
 	struct media_entity_notify *notify, *next;
-	unsigned int i;
+	struct media_pad *iter;
 	int ret;
 
 	if (entity->function == MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN ||
@@ -639,9 +639,8 @@ int __must_check media_device_register_entity(struct media_device *mdev,
 	media_gobj_create(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
 
 	/* Initialize objects at the pads */
-	for (i = 0; i < entity->num_pads; i++)
-		media_gobj_create(mdev, MEDIA_GRAPH_PAD,
-			       &entity->pads[i].graph_obj);
+	media_entity_for_each_pad(entity, iter)
+		media_gobj_create(mdev, MEDIA_GRAPH_PAD, &iter->graph_obj);
 
 	/* invoke entity_notify callbacks */
 	list_for_each_entry_safe(notify, next, &mdev->entity_notify, list)

drivers/media/mc/mc-entity.c

@@ -193,7 +193,8 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 			   struct media_pad *pads)
 {
 	struct media_device *mdev = entity->graph_obj.mdev;
-	unsigned int i;
+	struct media_pad *iter;
+	unsigned int i = 0;
 
 	if (num_pads >= MEDIA_ENTITY_MAX_PADS)
 		return -E2BIG;
@@ -204,12 +205,12 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 	if (mdev)
 		mutex_lock(&mdev->graph_mutex);
 
-	for (i = 0; i < num_pads; i++) {
-		pads[i].entity = entity;
-		pads[i].index = i;
+	media_entity_for_each_pad(entity, iter) {
+		iter->entity = entity;
+		iter->index = i++;
 		if (mdev)
 			media_gobj_create(mdev, MEDIA_GRAPH_PAD,
-					&entity->pads[i].graph_obj);
+					  &iter->graph_obj);
 	}
 
 	if (mdev)

include/media/media-entity.h

@@ -316,6 +316,18 @@ struct media_entity {
 	} info;
 };
 
+/**
+ * media_entity_for_each_pad - Iterate on all pads in an entity
+ * @entity: The entity the pads belong to
+ * @iter: The iterator pad
+ *
+ * Iterate on all pads in a media entity.
+ */
+#define media_entity_for_each_pad(entity, iter)			\
+	for (iter = (entity)->pads;				\
+	     iter < &(entity)->pads[(entity)->num_pads];	\
+	     ++iter)
+
 /**
  * struct media_interface - A media interface graph object.
  *