[PATCH v7 4/8] media: synopsys: Use media_async_register_subdev() to simplify code

[Frank.Li@oss.nxp.com]

From: Frank Li <Frank.Li@nxp.com>

Use the media_async_register_subdev() to simplify the driver.

Replace the local subdev registration and media pad setup code with
media_async_register_subdev(). Reduce boilerplate code and aligns the
driver with the common pattern used by simple subdevices that each media
pad has one endpoint in fwnode.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
chagne in v7
- keep bus_type in csi2 struture
- update set_pad_by_ep() argurment.

change in v6
- use media_async_register_subdev()
- remove sd_1to1.

change in v5
new patch

previous method:
https://lore.kernel.org/imx/20260226-v4l2_init_register-v2-2-902d7140f9fa@nxp.com/
---
 drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 172 +++++------------------
 1 file changed, 39 insertions(+), 133 deletions(-)

diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index f51367409ff46..0d8834e77a08a 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -78,12 +78,6 @@ enum dw_mipi_csi2rx_regs_index {
 	DW_MIPI_CSI2RX_MAX,
 };
 
-enum {
-	DW_MIPI_CSI2RX_PAD_SINK,
-	DW_MIPI_CSI2RX_PAD_SRC,
-	DW_MIPI_CSI2RX_PAD_MAX,
-};
-
 struct dw_mipi_csi2rx_device;
 
 struct dw_mipi_csi2rx_drvdata {
@@ -112,8 +106,6 @@ struct dw_mipi_csi2rx_device {
 	const struct dw_mipi_csi2rx_format *formats;
 	unsigned int formats_num;
 
-	struct media_pad pads[DW_MIPI_CSI2RX_PAD_MAX];
-	struct v4l2_async_notifier notifier;
 	struct v4l2_subdev sd;
 
 	enum v4l2_mbus_type bus_type;
@@ -360,9 +352,10 @@ dw_mipi_csi2rx_find_format(struct dw_mipi_csi2rx_device *csi2, u32 mbus_code)
 
 static int dw_mipi_csi2rx_start(struct dw_mipi_csi2rx_device *csi2)
 {
+	struct media_pad *sink_pad = &csi2->sd.entity.pads[V4L2_SUBDEV_1TO1_PADS_SINK];
+	u32 lanes = csi2->lanes_num;
 	struct media_pad *source_pad;
 	union phy_configure_opts opts;
-	u32 lanes = csi2->lanes_num;
 	u32 control = 0;
 	s64 link_freq;
 	int ret;
@@ -370,8 +363,7 @@ static int dw_mipi_csi2rx_start(struct dw_mipi_csi2rx_device *csi2)
 	if (lanes < 1 || lanes > 4)
 		return -EINVAL;
 
-	source_pad = media_pad_remote_pad_unique(
-		&csi2->pads[DW_MIPI_CSI2RX_PAD_SINK]);
+	source_pad = media_pad_remote_pad_unique(sink_pad);
 	if (IS_ERR(source_pad))
 		return PTR_ERR(source_pad);
 
@@ -458,16 +450,16 @@ dw_mipi_csi2rx_enum_mbus_code(struct v4l2_subdev *sd,
 	struct dw_mipi_csi2rx_device *csi2 = to_csi2(sd);
 
 	switch (code->pad) {
-	case DW_MIPI_CSI2RX_PAD_SRC:
+	case V4L2_SUBDEV_1TO1_PADS_SOURCE:
 		if (code->index)
 			return -EINVAL;
 
 		code->code =
 			v4l2_subdev_state_get_format(sd_state,
-						     DW_MIPI_CSI2RX_PAD_SINK)->code;
+						     V4L2_SUBDEV_1TO1_PADS_SINK)->code;
 
 		return 0;
-	case DW_MIPI_CSI2RX_PAD_SINK:
+	case V4L2_SUBDEV_1TO1_PADS_SINK:
 		if (code->index >= csi2->formats_num)
 			return -EINVAL;
 
@@ -487,7 +479,7 @@ static int dw_mipi_csi2rx_set_fmt(struct v4l2_subdev *sd,
 	struct v4l2_mbus_framefmt *sink, *src;
 
 	/* the format on the source pad always matches the sink pad */
-	if (format->pad == DW_MIPI_CSI2RX_PAD_SRC)
+	if (format->pad == V4L2_SUBDEV_1TO1_PADS_SOURCE)
 		return v4l2_subdev_get_fmt(sd, state, format);
 
 	sink = v4l2_subdev_state_get_format(state, format->pad, format->stream);
@@ -549,12 +541,12 @@ static int dw_mipi_csi2rx_enable_streams(struct v4l2_subdev *sd,
 	u64 mask;
 	int ret;
 
-	sink_pad = &sd->entity.pads[DW_MIPI_CSI2RX_PAD_SINK];
+	sink_pad = &sd->entity.pads[V4L2_SUBDEV_1TO1_PADS_SINK];
 	remote_pad = media_pad_remote_pad_first(sink_pad);
 	remote_sd = media_entity_to_v4l2_subdev(remote_pad->entity);
 
-	mask = v4l2_subdev_state_xlate_streams(state, DW_MIPI_CSI2RX_PAD_SINK,
-					       DW_MIPI_CSI2RX_PAD_SRC,
+	mask = v4l2_subdev_state_xlate_streams(state, V4L2_SUBDEV_1TO1_PADS_SINK,
+					       V4L2_SUBDEV_1TO1_PADS_SOURCE,
 					       &streams_mask);
 
 	if (!csi2->enabled_streams) {
@@ -608,12 +600,12 @@ static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
 	u64 mask;
 	int ret;
 
-	sink_pad = &sd->entity.pads[DW_MIPI_CSI2RX_PAD_SINK];
+	sink_pad = &sd->entity.pads[V4L2_SUBDEV_1TO1_PADS_SINK];
 	remote_pad = media_pad_remote_pad_first(sink_pad);
 	remote_sd = media_entity_to_v4l2_subdev(remote_pad->entity);
 
-	mask = v4l2_subdev_state_xlate_streams(state, DW_MIPI_CSI2RX_PAD_SINK,
-					       DW_MIPI_CSI2RX_PAD_SRC,
+	mask = v4l2_subdev_state_xlate_streams(state, V4L2_SUBDEV_1TO1_PADS_SINK,
+					       V4L2_SUBDEV_1TO1_PADS_SOURCE,
 					       &streams_mask);
 
 	ret = v4l2_subdev_disable_streams(remote_sd, remote_pad->index, mask);
@@ -649,9 +641,9 @@ static int dw_mipi_csi2rx_init_state(struct v4l2_subdev *sd,
 {
 	struct v4l2_subdev_route routes[] = {
 		{
-			.sink_pad = DW_MIPI_CSI2RX_PAD_SINK,
+			.sink_pad = V4L2_SUBDEV_1TO1_PADS_SINK,
 			.sink_stream = 0,
-			.source_pad = DW_MIPI_CSI2RX_PAD_SRC,
+			.source_pad = V4L2_SUBDEV_1TO1_PADS_SOURCE,
 			.source_stream = 0,
 			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
 		},
@@ -666,95 +658,42 @@ static int dw_mipi_csi2rx_init_state(struct v4l2_subdev *sd,
 						&default_format);
 }
 
-static const struct v4l2_subdev_internal_ops dw_mipi_csi2rx_internal_ops = {
-	.init_state = dw_mipi_csi2rx_init_state,
-};
-
-static int dw_mipi_csi2rx_notifier_bound(struct v4l2_async_notifier *notifier,
-					 struct v4l2_subdev *sd,
-					 struct v4l2_async_connection *asd)
+static int dw_mipi_set_pad_by_ep(struct v4l2_subdev *sd, struct media_pad *pad,
+				 struct v4l2_fwnode_endpoint *vep)
 {
-	struct dw_mipi_csi2rx_device *csi2 =
-		container_of(notifier, struct dw_mipi_csi2rx_device, notifier);
-	struct media_pad *sink_pad = &csi2->pads[DW_MIPI_CSI2RX_PAD_SINK];
-	int ret;
-
-	ret = v4l2_create_fwnode_links_to_pad(sd, sink_pad,
-					      MEDIA_LNK_FL_ENABLED);
-	if (ret) {
-		dev_err(csi2->dev, "failed to link source pad of %s\n",
-			sd->name);
-		return ret;
-	}
-
-	return 0;
-}
-
-static const struct v4l2_async_notifier_operations dw_mipi_csi2rx_notifier_ops = {
-	.bound = dw_mipi_csi2rx_notifier_bound,
-};
-
-static int dw_mipi_csi2rx_register_notifier(struct dw_mipi_csi2rx_device *csi2)
-{
-	struct v4l2_async_connection *asd;
-	struct v4l2_async_notifier *ntf = &csi2->notifier;
-	struct v4l2_fwnode_endpoint vep;
-	struct v4l2_subdev *sd = &csi2->sd;
-	struct device *dev = csi2->dev;
-	int ret;
-
-	struct fwnode_handle *ep __free(fwnode_handle) =
-		fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0, 0);
-	if (!ep)
-		return dev_err_probe(dev, -ENODEV, "failed to get endpoint\n");
-
-	vep.bus_type = V4L2_MBUS_UNKNOWN;
-	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
-	if (ret)
-		return dev_err_probe(dev, ret, "failed to parse endpoint\n");
+	if (vep->base.port == V4L2_SUBDEV_1TO1_PADS_SINK) {
+		if (vep->bus_type != V4L2_MBUS_CSI2_DPHY &&
+		    vep->bus_type != V4L2_MBUS_CSI2_CPHY)
+			return -EINVAL;
 
-	if (vep.bus_type != V4L2_MBUS_CSI2_DPHY &&
-	    vep.bus_type != V4L2_MBUS_CSI2_CPHY)
-		return dev_err_probe(dev, -EINVAL,
-				     "invalid bus type of endpoint\n");
+		struct dw_mipi_csi2rx_device *csi2 = to_csi2(sd);
 
-	csi2->bus_type = vep.bus_type;
-	csi2->lanes_num = vep.bus.mipi_csi2.num_data_lanes;
+		pad->flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
 
-	v4l2_async_subdev_nf_init(ntf, sd);
-	ntf->ops = &dw_mipi_csi2rx_notifier_ops;
+		csi2->bus_type = vep->bus_type;
+		csi2->lanes_num = vep->bus.mipi_csi2.num_data_lanes;
 
-	asd = v4l2_async_nf_add_fwnode_remote(ntf, ep,
-					      struct v4l2_async_connection);
-	if (IS_ERR(asd)) {
-		ret = PTR_ERR(asd);
-		goto err_nf_cleanup;
+		return 0;
 	}
 
-	ret = v4l2_async_nf_register(ntf);
-	if (ret) {
-		ret = dev_err_probe(dev, ret, "failed to register notifier\n");
-		goto err_nf_cleanup;
+	if (vep->base.port == V4L2_SUBDEV_1TO1_PADS_SOURCE) {
+		pad->flags = MEDIA_PAD_FL_SOURCE | MEDIA_PAD_FL_MUST_CONNECT;
+		return 0;
 	}
 
-	return 0;
-
-err_nf_cleanup:
-	v4l2_async_nf_cleanup(ntf);
-
-	return ret;
+	return -EINVAL;
 }
 
+static const struct v4l2_subdev_internal_ops dw_mipi_csi2rx_internal_ops = {
+	.init_state = dw_mipi_csi2rx_init_state,
+	.set_pad_by_ep = dw_mipi_set_pad_by_ep,
+};
+
 static int dw_mipi_csi2rx_register(struct dw_mipi_csi2rx_device *csi2)
 {
-	struct media_pad *pads = csi2->pads;
 	struct v4l2_subdev *sd = &csi2->sd;
 	int ret;
 
-	ret = dw_mipi_csi2rx_register_notifier(csi2);
-	if (ret)
-		goto err;
-
 	v4l2_subdev_init(sd, &dw_mipi_csi2rx_ops);
 	sd->dev = csi2->dev;
 	sd->entity.ops = &dw_mipi_csi2rx_media_ops;
@@ -764,45 +703,12 @@ static int dw_mipi_csi2rx_register(struct dw_mipi_csi2rx_device *csi2)
 	snprintf(sd->name, sizeof(sd->name), "dw-mipi-csi2rx %s",
 		 dev_name(csi2->dev));
 
-	pads[DW_MIPI_CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK |
-					      MEDIA_PAD_FL_MUST_CONNECT;
-	pads[DW_MIPI_CSI2RX_PAD_SRC].flags = MEDIA_PAD_FL_SOURCE;
-	ret = media_entity_pads_init(&sd->entity, DW_MIPI_CSI2RX_PAD_MAX, pads);
+	ret = media_async_register_subdev(&csi2->sd);
 	if (ret)
-		goto err_notifier_unregister;
-
-	ret = v4l2_subdev_init_finalize(sd);
-	if (ret)
-		goto err_entity_cleanup;
-
-	ret = v4l2_async_register_subdev(sd);
-	if (ret) {
-		dev_err(sd->dev, "failed to register CSI-2 subdev\n");
-		goto err_subdev_cleanup;
-	}
+		return dev_err_probe(sd->dev, ret,
+				     "failed to register CSI-2 subdev\n");
 
 	return 0;
-
-err_subdev_cleanup:
-	v4l2_subdev_cleanup(sd);
-err_entity_cleanup:
-	media_entity_cleanup(&sd->entity);
-err_notifier_unregister:
-	v4l2_async_nf_unregister(&csi2->notifier);
-	v4l2_async_nf_cleanup(&csi2->notifier);
-err:
-	return ret;
-}
-
-static void dw_mipi_csi2rx_unregister(struct dw_mipi_csi2rx_device *csi2)
-{
-	struct v4l2_subdev *sd = &csi2->sd;
-
-	v4l2_async_unregister_subdev(sd);
-	v4l2_subdev_cleanup(sd);
-	media_entity_cleanup(&sd->entity);
-	v4l2_async_nf_unregister(&csi2->notifier);
-	v4l2_async_nf_cleanup(&csi2->notifier);
 }
 
 static void imx93_csi2rx_dphy_assert_reset(struct dw_mipi_csi2rx_device *csi2)
@@ -993,7 +899,7 @@ static void dw_mipi_csi2rx_remove(struct platform_device *pdev)
 {
 	struct dw_mipi_csi2rx_device *csi2 = platform_get_drvdata(pdev);
 
-	dw_mipi_csi2rx_unregister(csi2);
+	media_async_subdev_cleanup(&csi2->sd);
 	phy_exit(csi2->phy);
 }
 

-- 
2.43.0