[PATCH v12 01/86] media: mc: Add INTERNAL pad flag

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Internal sink pads will be used as routing endpoints in V4L2 [GS]_ROUTING
IOCTLs, to indicate that the stream begins in the entity. Internal sink
pads are pads that have both SINK and INTERNAL flags set.

Also prevent creating links to pads that have been flagged as internal and
initialising SOURCE pads with INTERNAL flag set.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Mirela Rabulea <mirela.rabulea@nxp.com>
---
 .../userspace-api/media/mediactl/media-types.rst  |  8 ++++++++
 drivers/media/mc/mc-entity.c                      | 15 ++++++++++++---
 include/uapi/linux/media.h                        |  1 +
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/Documentation/userspace-api/media/mediactl/media-types.rst b/Documentation/userspace-api/media/mediactl/media-types.rst
index d6a690655a01..032f55ea0b33 100644
--- a/Documentation/userspace-api/media/mediactl/media-types.rst
+++ b/Documentation/userspace-api/media/mediactl/media-types.rst
@@ -361,6 +361,7 @@ Types and flags used to represent the media graph elements
 .. _MEDIA-PAD-FL-SINK:
 .. _MEDIA-PAD-FL-SOURCE:
 .. _MEDIA-PAD-FL-MUST-CONNECT:
+.. _MEDIA-PAD-FL-INTERNAL:
 
 .. flat-table:: Media pad flags
     :header-rows:  0
@@ -381,6 +382,13 @@ Types and flags used to represent the media graph elements
 	  enabled links even when this flag isn't set; the absence of the flag
 	  doesn't imply there is none.
 
+    *  -  ``MEDIA_PAD_FL_INTERNAL``
+       -  The internal flag indicates an internal pad that has no external
+	  connections. As they are internal to entities, internal pads shall not
+	  be connected with links.
+
+	  The internal flag may currently be present only in a sink pad where it
+	  indicates that the :term:`Stream` originates from within the entity.
 
 One and only one of ``MEDIA_PAD_FL_SINK`` and ``MEDIA_PAD_FL_SOURCE``
 must be set for every pad.
diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 5b0162f81425..0373ca7afc16 100644
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -209,11 +209,16 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 		mutex_lock(&mdev->graph_mutex);
 
 	media_entity_for_each_pad(entity, iter) {
+		const u32 pad_flags = iter->flags & (MEDIA_PAD_FL_SINK |
+						     MEDIA_PAD_FL_SOURCE |
+						     MEDIA_PAD_FL_INTERNAL);
+
 		iter->entity = entity;
 		iter->index = i++;
 
-		if (hweight32(iter->flags & (MEDIA_PAD_FL_SINK |
-					     MEDIA_PAD_FL_SOURCE)) != 1) {
+		if (pad_flags != MEDIA_PAD_FL_SINK &&
+		    pad_flags != (MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_INTERNAL) &&
+		    pad_flags != MEDIA_PAD_FL_SOURCE) {
 			ret = -EINVAL;
 			break;
 		}
@@ -1174,7 +1179,8 @@ int media_get_pad_index(struct media_entity *entity, u32 pad_type,
 
 	for (i = 0; i < entity->num_pads; i++) {
 		if ((entity->pads[i].flags &
-		     (MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_SOURCE)) != pad_type)
+		     (MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_SOURCE |
+		      MEDIA_PAD_FL_INTERNAL)) != pad_type)
 			continue;
 
 		if (entity->pads[i].sig_type == sig_type)
@@ -1204,6 +1210,9 @@ media_create_pad_link(struct media_entity *source, u16 source_pad,
 		return -EINVAL;
 	if (WARN_ON(!(sink->pads[sink_pad].flags & MEDIA_PAD_FL_SINK)))
 		return -EINVAL;
+	if (WARN_ON(source->pads[source_pad].flags & MEDIA_PAD_FL_INTERNAL) ||
+	    WARN_ON(sink->pads[sink_pad].flags & MEDIA_PAD_FL_INTERNAL))
+		return -EINVAL;
 
 	/*
 	 * With the late validate flag, either source or sink shall have exactly
diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h
index c96e2118ea99..39e0a778edb5 100644
--- a/include/uapi/linux/media.h
+++ b/include/uapi/linux/media.h
@@ -208,6 +208,7 @@ struct media_entity_desc {
 #define MEDIA_PAD_FL_SINK			(1U << 0)
 #define MEDIA_PAD_FL_SOURCE			(1U << 1)
 #define MEDIA_PAD_FL_MUST_CONNECT		(1U << 2)
+#define MEDIA_PAD_FL_INTERNAL			(1U << 3)
 
 struct media_pad_desc {
 	__u32 entity;		/* entity ID */
-- 
2.47.3