net: dsa: support dsa protocol registering with iterable section

Supported dsa protocol registering with iterable section.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>

cmake/linker_script/common/common-rom.cmake

@@ -240,6 +240,10 @@ if(CONFIG_NET_SOCKETS_SERVICE)
   )
 endif()
 
+if(CONFIG_NET_DSA)
+  zephyr_iterable_section(NAME dsa_tag_register KVMA RAM_REGION GROUP RODATA_REGION)
+endif()
+
 if(CONFIG_INPUT)
   zephyr_iterable_section(NAME input_callback KVMA RAM_REGION GROUP RODATA_REGION)
 endif()

include/zephyr/linker/common-rom/common-rom-net.ld

@@ -33,3 +33,7 @@
 #if defined(CONFIG_NET_SOCKETS_SERVICE)
 	ITERABLE_SECTION_ROM(net_socket_service_desc, Z_LINK_ITERABLE_SUBALIGN)
 #endif
+
+#if defined(CONFIG_NET_DSA)
+	ITERABLE_SECTION_ROM(dsa_tag_register, Z_LINK_ITERABLE_SUBALIGN)
+#endif

include/zephyr/net/dsa_tag.h

@@ -21,14 +21,32 @@
  */
 
 #include <zephyr/dt-bindings/ethernet/dsa_tag_proto.h>
-#ifdef CONFIG_DSA_TAG_PROTOCOL_NETC
-#include <zephyr/net/dsa_tag_netc.h>
-#endif
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/**
+ * @brief Registration information for a dsa tag protocol
+ */
+struct dsa_tag_register {
+	/** Protocol ID */
+	int proto;
+
+	/** Received packet handler */
+	struct net_if *(*recv)(struct net_if *iface, struct net_pkt *pkt);
+
+	/** Transmit packet handler */
+	struct net_pkt *(*xmit)(struct net_if *iface, struct net_pkt *pkt);
+};
+
+#define DSA_TAG_REGISTER(_proto, _recv, _xmit)                                                     \
+	static const STRUCT_SECTION_ITERABLE(dsa_tag_register, __dsa_tag_register_##_proto) = {    \
+		.proto = _proto,                                                                   \
+		.recv = _recv,                                                                     \
+		.xmit = _xmit,                                                                     \
+	}
+
 /** @cond INTERNAL_HIDDEN */
 
 /*

include/zephyr/net/dsa_tag_netc.h

@@ -1,6 +1,5 @@
 /*
- * Copyright 2025 NXP
- *
+ * SPDX-FileCopyrightText: Copyright 2025-2026 NXP
  * SPDX-License-Identifier: Apache-2.0
  */
 #ifndef ZEPHYR_SUBSYS_DSA_TAG_NETC_H_
@@ -13,6 +12,4 @@ struct dsa_tag_netc_data {
 #endif
 };
 
-struct net_if *dsa_tag_netc_recv(struct net_if *iface, struct net_pkt *pkt);
-struct net_pkt *dsa_tag_netc_xmit(struct net_if *iface, struct net_pkt *pkt);
 #endif /* ZEPHYR_SUBSYS_DSA_TAG_NETC_H_ */

subsys/net/l2/ethernet/dsa/dsa_tag.c

@@ -44,19 +44,18 @@ void dsa_tag_setup(const struct device *dev_cpu)
 {
 	const struct dsa_port_config *cfg = dev_cpu->config;
 	struct dsa_switch_context *dsa_switch_ctx = dev_cpu->data;
+	bool match = false;
 
-	switch (cfg->tag_proto) {
-#ifdef CONFIG_DSA_TAG_PROTOCOL_NETC
-	case DSA_TAG_PROTO_NETC:
-		dsa_switch_ctx->dapi->recv = dsa_tag_netc_recv;
-		dsa_switch_ctx->dapi->xmit = dsa_tag_netc_xmit;
-		break;
-#endif
-	case DSA_TAG_PROTO_NOTAG:
-		dsa_switch_ctx->dapi->recv = NULL;
-		dsa_switch_ctx->dapi->xmit = NULL;
-		break;
-	default:
+	STRUCT_SECTION_FOREACH(dsa_tag_register, tag) {
+		if (tag->proto == cfg->tag_proto) {
+			dsa_switch_ctx->dapi->recv = tag->recv;
+			dsa_switch_ctx->dapi->xmit = tag->xmit;
+			match = true;
+			break;
+		}
+	}
+
+	if ((!match) && (cfg->tag_proto != DSA_TAG_PROTO_NOTAG)) {
 		LOG_ERR("DSA tag protocol %d not supported", cfg->tag_proto);
 	}
 

subsys/net/l2/ethernet/dsa/dsa_tag_netc.c

@@ -1,6 +1,5 @@
 /*
- * Copyright 2025 NXP
- *
+ * SPDX-FileCopyrightText: Copyright 2025-2026 NXP
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -9,6 +8,7 @@ LOG_MODULE_REGISTER(net_dsa_tag_netc, CONFIG_NET_DSA_LOG_LEVEL);
 
 #include <zephyr/net/ethernet.h>
 #include <zephyr/net/dsa_core.h>
+#include <zephyr/net/dsa_tag.h>
 #include <zephyr/net/dsa_tag_netc.h>
 #include "fsl_netc_tag.h"
 
@@ -157,3 +157,5 @@ struct net_pkt *dsa_tag_netc_xmit(struct net_if *iface, struct net_pkt *pkt)
 	net_pkt_cursor_init(pkt);
 	return pkt;
 }
+
+DSA_TAG_REGISTER(DSA_TAG_PROTO_NETC, dsa_tag_netc_recv, dsa_tag_netc_xmit);