[media] media: Change media device link_notify behaviour

Currently the media device link_notify callback is invoked before the
actual change of state of a link when the link is being enabled, and
after the actual change of state when the link is being disabled.
This doesn't allow a media device driver to perform any operations
on a full graph before a link is disabled, as well as performing
any tasks on a modified graph right after a link's state is changed.
This patch modifies signature of the link_notify callback. This
callback is now called always before and after a link's state change.
To distinguish the notifications a 'notification' argument is added
to the link_notify callback: MEDIA_DEV_NOTIFY_PRE_LINK_CH indicates
notification before link's state change and
MEDIA_DEV_NOTIFY_POST_LINK_CH corresponds to a notification after
link flags change.

[mchehab@redhat.com: whitespace cleanups]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/media/media-device.h b/include/media/media-device.h
index eaade9815bb6..12155a9596c4 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -45,6 +45,7 @@ struct device;
  * @entities:	List of registered entities
  * @lock:	Entities list lock
  * @graph_mutex: Entities graph operation lock
+ * @link_notify: Link state change notification callback
  *
  * This structure represents an abstract high-level media device. It allows easy
  * access to entities and provides basic media device-level support. The
@@ -75,10 +76,14 @@ struct media_device {
 	/* Serializes graph operations. */
 	struct mutex graph_mutex;
 
-	int (*link_notify)(struct media_pad *source,
-			   struct media_pad *sink, u32 flags);
+	int (*link_notify)(struct media_link *link, u32 flags,
+			   unsigned int notification);
 };
 
+/* Supported link_notify @notification values. */
+#define MEDIA_DEV_NOTIFY_PRE_LINK_CH	0
+#define MEDIA_DEV_NOTIFY_POST_LINK_CH	1
+
 /* media_devnode to media_device */
 #define to_media_device(node) container_of(node, struct media_device, devnode)