net: dsa: add NXP NETC tag protocol driver

Added NXP NETC tag protocol driver.

Signed-off-by: Yangbo Lu <[email protected]>

Author: yangbolu1991

subsys/net/l2/ethernet/dsa/CMakeLists.txt

@@ -8,4 +8,5 @@ zephyr_library_sources(dsa_core.c)
 zephyr_library_sources(dsa_port.c)
 zephyr_library_sources(dsa_user.c)
 zephyr_library_sources(dsa_tag.c)
+zephyr_library_sources_ifdef(CONFIG_DSA_TAG_PROTOCOL_NETC dsa_tag_netc.c)
 endif()

subsys/net/l2/ethernet/dsa/Kconfig

@@ -12,6 +12,8 @@ menuconfig NET_DSA
 
 if NET_DSA
 
+DSA_PORT_COMPAT := zephyr,dsa-port
+
 config NET_DSA_DEPRECATED
 	bool "Distributed Switch Architecture support for legacy device"
 	select DEPRECATED
@@ -33,6 +35,14 @@ config DSA_TAG_SIZE
 	help
 	  Set the DSA tag length in bytes.
 
+# Tag protocol ID found in <zephyr/dt-bindings/ethernet/dsa_tag_proto.h>
+config DSA_TAG_PROTOCOL_NETC
+	bool "Tag protocol - NETC"
+	default y
+	depends on $(dt_compat_any_has_prop,$(DSA_PORT_COMPAT),dsa-tag-protocol,1)
+	help
+	  NXP NETC tag protocol.
+
 module = NET_DSA
 module-dep = NET_LOG
 module-str = Log level for DSA

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

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(net_dsa_tag_netc, CONFIG_NET_DSA_LOG_LEVEL);
+
+#include <zephyr/net/ethernet.h>
+#include <zephyr/net/dsa_core.h>
+#include "dsa_tag_netc.h"
+#include "fsl_netc_tag.h"
+
+/* tag is inserted after DMAC/SMAC fields */
+struct dsa_tag_netc_to_host_header {
+	uint8_t dmac[NET_ETH_ADDR_LEN];
+	uint8_t smac[NET_ETH_ADDR_LEN];
+	netc_swt_tag_host_t tag;
+};
+
+struct dsa_tag_netc_to_port_header {
+	uint8_t dmac[NET_ETH_ADDR_LEN];
+	uint8_t smac[NET_ETH_ADDR_LEN];
+	netc_swt_tag_port_no_ts_t tag;
+};
+
+struct net_if *dsa_tag_netc_recv(struct net_if *iface, struct net_pkt *pkt)
+{
+	struct ethernet_context *eth_ctx = net_if_l2_data(iface);
+	uint16_t header_len = sizeof(struct dsa_tag_netc_to_host_header);
+	struct dsa_tag_netc_to_host_header *header;
+	struct net_if *iface_dst = iface;
+	uint8_t *ptr;
+
+	if (pkt->frags->len < header_len) {
+		LOG_ERR("tag len error");
+		return iface_dst;
+	}
+
+	/* redirect to user port */
+	header = (struct dsa_tag_netc_to_host_header *)pkt->frags->data;
+	iface_dst = eth_ctx->dsa_switch_ctx->iface_user[header->tag.comTag.port];
+
+	/* drop tag */
+	ptr = net_buf_pull(pkt->frags, sizeof(netc_swt_tag_host_t));
+	for (int i = 0; i < (NET_ETH_ADDR_LEN * 2); i++) {
+		ptr[i] = *(uint8_t *)((uintptr_t)header + i);
+	}
+
+	return iface_dst;
+}
+
+struct net_pkt *dsa_tag_netc_xmit(struct net_if *iface, struct net_pkt *pkt)
+{
+	const struct device *dev = net_if_get_device(iface);
+	struct dsa_port_config *cfg = (struct dsa_port_config *)dev->config;
+	struct dsa_tag_netc_to_port_header *header;
+	struct net_buf *header_buf;
+
+	/* Allocate net_buf for header */
+	header_buf = net_buf_alloc_len(net_buf_pool_get(pkt->buffer->pool_id),
+				       sizeof(*header), K_NO_WAIT);
+	if (!header_buf) {
+		LOG_ERR("Cannot allocate header buffer");
+		return NULL;
+	}
+
+	header_buf->len = sizeof(*header);
+
+	/* Fill the header */
+	header = (struct dsa_tag_netc_to_port_header *)header_buf->data;
+	memcpy(header, pkt->frags->data, NET_ETH_ADDR_LEN * 2);
+	header->tag.comTag.tpid = NETC_SWITCH_DEFAULT_ETHER_TYPE;
+	header->tag.comTag.subType = kNETC_TagToPortNoTs;
+	header->tag.comTag.type = kNETC_TagToPort;
+	header->tag.comTag.swtId = 1;
+	header->tag.comTag.port = cfg->port_idx;
+
+	/* Drop DMAC/SMAC on original frag */
+	net_buf_pull(pkt->frags, NET_ETH_ADDR_LEN * 2);
+
+	/* Insert header */
+	header_buf->frags = pkt->frags;
+	pkt->frags = header_buf;
+
+	net_pkt_cursor_init(pkt);
+	return pkt;
+}

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

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#ifndef ZEPHYR_SUBSYS_DSA_TAG_NETC_H_
+#define ZEPHYR_SUBSYS_DSA_TAG_NETC_H_
+
+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_ */