[media] media: Links setup

Create the following ioctl and implement it at the media device level to
setup links.

- MEDIA_IOC_SETUP_LINK: Modify the properties of a given link

The only property that can currently be modified is the ENABLED link
flag to enable/disable a link. Links marked with the IMMUTABLE link flag
can not be enabled or disabled.

Enabling or disabling a link has effects on entities' use count. Those
changes are automatically propagated through the graph.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 51bdafce72c7..d889dcc67d0d 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -39,6 +39,12 @@ struct media_pad {
 	unsigned long flags;		/* Pad flags (MEDIA_PAD_FL_*) */
 };
 
+struct media_entity_operations {
+	int (*link_setup)(struct media_entity *entity,
+			  const struct media_pad *local,
+			  const struct media_pad *remote, u32 flags);
+};
+
 struct media_entity {
 	struct list_head list;
 	struct media_device *parent;	/* Media device this entity belongs to*/
@@ -59,6 +65,8 @@ struct media_entity {
 	struct media_pad *pads;		/* Pads array (num_pads elements) */
 	struct media_link *links;	/* Links array (max_links elements)*/
 
+	const struct media_entity_operations *ops;	/* Entity operations */
+
 	/* Reference counts must never be negative, but are signed integers on
 	 * purpose: a simple WARN_ON(<0) check can be used to detect reference
 	 * count bugs that would make them negative.
@@ -112,6 +120,11 @@ int media_entity_init(struct media_entity *entity, u16 num_pads,
 void media_entity_cleanup(struct media_entity *entity);
 int media_entity_create_link(struct media_entity *source, u16 source_pad,
 		struct media_entity *sink, u16 sink_pad, u32 flags);
+int __media_entity_setup_link(struct media_link *link, u32 flags);
+int media_entity_setup_link(struct media_link *link, u32 flags);
+struct media_link *media_entity_find_link(struct media_pad *source,
+		struct media_pad *sink);
+struct media_pad *media_entity_remote_source(struct media_pad *pad);
 
 struct media_entity *media_entity_get(struct media_entity *entity);
 void media_entity_put(struct media_entity *entity);
@@ -121,4 +134,8 @@ void media_entity_graph_walk_start(struct media_entity_graph *graph,
 struct media_entity *
 media_entity_graph_walk_next(struct media_entity_graph *graph);
 
+#define media_entity_call(entity, operation, args...)			\
+	(((entity)->ops && (entity)->ops->operation) ?			\
+	 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
+
 #endif