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From:   Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
To:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        sakari.ailus@linux.intel.com,
        Jacopo Mondi <jacopo+renesas@jmondi.org>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        niklas.soderlund+renesas@ragnatech.se,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        satish.nagireddy@getcruise.com, Tomasz Figa <tfiga@chromium.org>
Cc:     Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Subject: [PATCH v16 07/20] media: subdev: add v4l2_subdev_has_pad_interdep()
Date:   Thu, 15 Dec 2022 14:16:21 +0200
Message-Id: <20221215121634.287100-8-tomi.valkeinen@ideasonboard.com>
In-Reply-To: <20221215121634.287100-1-tomi.valkeinen@ideasonboard.com>
References: <20221215121634.287100-1-tomi.valkeinen@ideasonboard.com>
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Add a v4l2_subdev_has_pad_interdep() helper function which can be used
for media_entity_operations.has_pad_interdep op.

It considers two pads interdependent if there is an active route between
pad0 and pad1.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 31 +++++++++++++++++++++++++++
 include/media/v4l2-subdev.h           | 18 ++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index c31b44800e39..b16121485f79 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1056,6 +1056,37 @@ int v4l2_subdev_link_validate(struct media_link *link)
 }
 EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate);
 
+bool v4l2_subdev_has_pad_interdep(struct media_entity *entity,
+				  unsigned int pad0, unsigned int pad1)
+{
+	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
+	struct v4l2_subdev_krouting *routing;
+	struct v4l2_subdev_state *state;
+	unsigned int i;
+
+	state = v4l2_subdev_lock_and_get_active_state(sd);
+
+	routing = &state->routing;
+
+	for (i = 0; i < routing->num_routes; ++i) {
+		struct v4l2_subdev_route *route = &routing->routes[i];
+
+		if (!(route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
+			continue;
+
+		if ((route->sink_pad == pad0 && route->source_pad == pad1) ||
+		    (route->source_pad == pad0 && route->sink_pad == pad1)) {
+			v4l2_subdev_unlock_state(state);
+			return true;
+		}
+	}
+
+	v4l2_subdev_unlock_state(state);
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_has_pad_interdep);
+
 struct v4l2_subdev_state *
 __v4l2_subdev_state_alloc(struct v4l2_subdev *sd, const char *lock_name,
 			  struct lock_class_key *lock_key)
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 4934dc9468a8..45c41f4d6a2b 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1241,6 +1241,24 @@ int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd,
  */
 int v4l2_subdev_link_validate(struct media_link *link);
 
+/**
+ * v4l2_subdev_has_pad_interdep - MC has_pad_interdep implementation for subdevs
+ *
+ * @entity: pointer to &struct media_entity
+ * @pad0: pad number for the first pad
+ * @pad1: pad number for the second pad
+ *
+ * This function is an implementation of the
+ * media_entity_operations.has_pad_interdep operation for subdevs that
+ * implement the multiplexed streams API (as indicated by the
+ * V4L2_SUBDEV_FL_STREAMS subdev flag).
+ *
+ * It considers two pads interdependent if there is an active route between pad0
+ * and pad1.
+ */
+bool v4l2_subdev_has_pad_interdep(struct media_entity *entity,
+				  unsigned int pad0, unsigned int pad1);
+
 /**
  * __v4l2_subdev_state_alloc - allocate v4l2_subdev_state
  *
-- 
2.34.1