[media] media: use media_gobj inside pads

PADs also need unique object IDs that won't conflict with
the entity object IDs.

The pad objects are currently created via media_entity_init()
and, once created, never change.

While this will likely change in the future in order to
support dynamic changes, for now we'll keep PADs as arrays
and initialize the media_gobj embedded structs when
registering the entity.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 81d6a13..3bdda16 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -427,6 +427,8 @@
 int __must_check media_device_register_entity(struct media_device *mdev,
 					      struct media_entity *entity)
 {
+	int i;
+
 	/* Warn if we apparently re-register an entity */
 	WARN_ON(entity->parent != NULL);
 	entity->parent = mdev;
@@ -435,6 +437,12 @@
 	/* Initialize media_gobj embedded at the entity */
 	media_gobj_init(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
 	list_add_tail(&entity->list, &mdev->entities);
+
+	/* Initialize objects at the pads */
+	for (i = 0; i < entity->num_pads; i++)
+		media_gobj_init(mdev, MEDIA_GRAPH_PAD,
+			       &entity->pads[i].graph_obj);
+
 	spin_unlock(&mdev->lock);
 
 	return 0;
@@ -450,12 +458,15 @@
  */
 void media_device_unregister_entity(struct media_entity *entity)
 {
+	int i;
 	struct media_device *mdev = entity->parent;
 
 	if (mdev == NULL)
 		return;
 
 	spin_lock(&mdev->lock);
+	for (i = 0; i < entity->num_pads; i++)
+		media_gobj_remove(&entity->pads[i].graph_obj);
 	media_gobj_remove(&entity->graph_obj);
 	list_del(&entity->list);
 	spin_unlock(&mdev->lock);
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index 9f6f056..2d94c85 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -48,6 +48,9 @@
 	case MEDIA_GRAPH_ENTITY:
 		gobj->id = media_gobj_gen_id(type, ++mdev->entity_id);
 		break;
+	case MEDIA_GRAPH_PAD:
+		gobj->id = media_gobj_gen_id(type, ++mdev->pad_id);
+		break;
 	}
 }