media: cadence: Use v4l2_async_notifier_add_fwnode_remote_subdev

The use of v4l2_async_notifier_add_subdev will be discouraged.
Drivers are instead encouraged to use a helper such as
v4l2_async_notifier_add_fwnode_remote_subdev.

This fixes a misuse of the API, as v4l2_async_notifier_add_subdev
should get a kmalloc'ed struct v4l2_async_subdev,
removing some boilerplate code while at it.

Use the appropriate helper v4l2_async_notifier_add_fwnode_remote_subdev,
which handles the needed setup, instead of open-coding it.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/cadence/cdns-csi2rx.c

@@ -81,7 +81,6 @@ struct csi2rx_priv {
 	struct media_pad		pads[CSI2RX_PAD_MAX];
 
 	/* Remote source */
-	struct v4l2_async_subdev	asd;
 	struct v4l2_subdev		*source_subdev;
 	int				source_pad;
 };
@@ -362,6 +361,7 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
 static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
 {
 	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
+	struct v4l2_async_subdev *asd;
 	struct fwnode_handle *fwh;
 	struct device_node *ep;
 	int ret;
@@ -395,17 +395,13 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
 		return -EINVAL;
 	}
 
-	csi2rx->asd.match.fwnode = fwnode_graph_get_remote_port_parent(fwh);
-	csi2rx->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-	of_node_put(ep);
-
 	v4l2_async_notifier_init(&csi2rx->notifier);
 
-	ret = v4l2_async_notifier_add_subdev(&csi2rx->notifier, &csi2rx->asd);
-	if (ret) {
-		fwnode_handle_put(csi2rx->asd.match.fwnode);
-		return ret;
-	}
+	asd = v4l2_async_notifier_add_fwnode_remote_subdev(&csi2rx->notifier,
+							   fwh, sizeof(*asd));
+	of_node_put(ep);
+	if (IS_ERR(asd))
+		return PTR_ERR(asd);
 
 	csi2rx->notifier.ops = &csi2rx_notifier_ops;