[PATCH 11/13] media: v4l2-subdev: Introduce v4l2_subdev_find_route()

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

v4l2_subdev_find_route() is like v4l2_subdev_routing_find_opposite_end(),
with the difference that it's more flexible: it can look up only active
routes and can find multiple routes, too.

v4l2_subdev_find_route() is intended to replace
v4l2_subdev_routing_find_opposite_end().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 56 ++++++++++++++++++---------
 include/media/v4l2-subdev.h           | 19 +++++++++
 2 files changed, 56 insertions(+), 19 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index c549a462dac7..13d6e96daf3a 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1996,34 +1996,52 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
 }
 EXPORT_SYMBOL_GPL(v4l2_subdev_set_routing_with_fmt);
 
-int v4l2_subdev_routing_find_opposite_end(const struct v4l2_subdev_krouting *routing,
-					  u32 pad, u32 stream, u32 *other_pad,
-					  u32 *other_stream)
+struct v4l2_subdev_route *
+v4l2_subdev_find_route(const struct v4l2_subdev_krouting *routing,
+		       u32 pad, u32 stream, bool active, unsigned int index)
 {
 	unsigned int i;
 
 	for (i = 0; i < routing->num_routes; ++i) {
 		struct v4l2_subdev_route *route = &routing->routes[i];
 
-		if (route->source_pad == pad &&
-		    route->source_stream == stream) {
-			if (other_pad)
-				*other_pad = route->sink_pad;
-			if (other_stream)
-				*other_stream = route->sink_stream;
-			return 0;
-		}
+		if (active && !(route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
+			continue;
 
-		if (route->sink_pad == pad && route->sink_stream == stream) {
-			if (other_pad)
-				*other_pad = route->source_pad;
-			if (other_stream)
-				*other_stream = route->source_stream;
-			return 0;
-		}
+		if ((route->source_pad != pad ||
+		     route->source_stream != stream) &&
+		    (route->sink_pad != pad || route->sink_stream != stream))
+			continue;
+
+		if (index--)
+			continue;
+
+		return route;
 	}
 
-	return -EINVAL;
+	return ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_find_route);
+
+int v4l2_subdev_routing_find_opposite_end(const struct v4l2_subdev_krouting *routing,
+					  u32 pad, u32 stream, u32 *other_pad,
+					  u32 *other_stream)
+{
+	struct v4l2_subdev_route *route;
+
+	route = v4l2_subdev_find_route(routing, pad, stream, false, 0);
+	if (IS_ERR(route))
+		return PTR_ERR(route);
+
+	bool is_source = route->source_pad == pad;
+
+	if (other_pad)
+		*other_pad = is_source ? route->sink_pad : route->source_pad;
+	if (other_stream)
+		*other_stream = is_source ?
+			route->sink_stream : route->source_stream;
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_subdev_routing_find_opposite_end);
 
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index deab128a4779..9ed8600ba3d4 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1547,6 +1547,23 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
 				     const struct v4l2_subdev_krouting *routing,
 				     const struct v4l2_mbus_framefmt *fmt);
 
+/**
+ * v4l2_subdev_find_route() - Find routes from a (pad, stream) pair
+ * @routing: routing used to find the opposite side
+ * @pad: pad id
+ * @stream: stream id
+ * @active: set to true for looking up only active routes
+ * @index: for accessing more than one route from the pad
+ *
+ * Find a route from the routing table where one end has (pad, stream) pair
+ * matching @pad and @stream.
+ *
+ * Returns the route on success or -ENOENT if no matching route is found.
+ */
+struct v4l2_subdev_route *
+v4l2_subdev_find_route(const struct v4l2_subdev_krouting *routing,
+		       u32 pad, u32 stream, bool active, unsigned int index);
+
 /**
  * v4l2_subdev_routing_find_opposite_end() - Find the opposite stream
  * @routing: routing used to find the opposite side
@@ -1555,6 +1572,8 @@ int v4l2_subdev_set_routing_with_fmt(struct v4l2_subdev *sd,
  * @other_pad: pointer used to return the opposite pad
  * @other_stream: pointer used to return the opposite stream
  *
+ * Prefer v4l2_subdev_find_route() over v4l2_subdev_routing_find_opposite_end().
+ *
  * This function uses the routing table to find the pad + stream which is
  * opposite the given pad + stream.
  *
-- 
2.39.5