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[4.19.y-cip,03/40] media: v4l2-async: Accept endpoints and devices for fwnode matching

Message ID 20210309163656.20944-4-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State Accepted
Delegated to: Nobuhiro Iwamatsu
Headers show
Series Renesas RZ/G2{E,H,M,N} add VIN, CSI2 support | expand

Commit Message

Lad Prabhakar March 9, 2021, 4:36 p.m. UTC
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

commit b98158d837efa0b2f2f59ee2ff77f4791f978d74 upstream.

fwnode matching was designed to match on nodes corresponding to a
device. Some drivers, however, needed to match on endpoints, and have
passed endpoint fwnodes to v4l2-async. This works when both the subdev
and the notifier use the same fwnode types (endpoint or device), but
makes drivers that use different types incompatible.

Fix this by extending the fwnode match to handle fwnodes of different
types. When the types (deduced from the presence of remote endpoints)
are different, retrieve the device fwnode for the side that provides an
endpoint fwnode, and compare it with the device fwnode provided by the
other side. This allows interoperability between all drivers, regardless
of which type of fwnode they use for matching.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 43 +++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 2b08d03b251d..72f8c070ad9d 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -73,7 +73,48 @@  static bool match_devname(struct v4l2_subdev *sd,
 
 static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
 {
-	return sd->fwnode == asd->match.fwnode;
+	struct fwnode_handle *other_fwnode;
+	struct fwnode_handle *dev_fwnode;
+	bool asd_fwnode_is_ep;
+	bool sd_fwnode_is_ep;
+
+	/*
+	 * Both the subdev and the async subdev can provide either an endpoint
+	 * fwnode or a device fwnode. Start with the simple case of direct
+	 * fwnode matching.
+	 */
+	if (sd->fwnode == asd->match.fwnode)
+		return true;
+
+	/*
+	 * Otherwise, check if the sd fwnode and the asd fwnode refer to an
+	 * endpoint or a device. If they're of the same type, there's no match.
+	 * Technically speaking this checks if the nodes refer to a connected
+	 * endpoint, which is the simplest check that works for both OF and
+	 * ACPI. This won't make a difference, as drivers should not try to
+	 * match unconnected endpoints.
+	 */
+	sd_fwnode_is_ep = fwnode_graph_is_endpoint(sd->fwnode);
+	asd_fwnode_is_ep = fwnode_graph_is_endpoint(asd->match.fwnode);
+
+	if (sd_fwnode_is_ep == asd_fwnode_is_ep)
+		return false;
+
+	/*
+	 * The sd and asd fwnodes are of different types. Get the device fwnode
+	 * parent of the endpoint fwnode, and compare it with the other fwnode.
+	 */
+	if (sd_fwnode_is_ep) {
+		dev_fwnode = fwnode_graph_get_port_parent(sd->fwnode);
+		other_fwnode = asd->match.fwnode;
+	} else {
+		dev_fwnode = fwnode_graph_get_port_parent(asd->match.fwnode);
+		other_fwnode = sd->fwnode;
+	}
+
+	fwnode_handle_put(dev_fwnode);
+
+	return dev_fwnode == other_fwnode;
 }
 
 static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)