drivers: ethernet: Introduce ETH_DRIVER_RAW_MODE option

Add a Kconfig symbol to allow building ethernet device driver without
an L2 layer.

Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>

drivers/ethernet/Kconfig

@@ -5,12 +5,21 @@
 
 menuconfig ETH_DRIVER
 	bool "Ethernet drivers"
-	default y
-	depends on NET_L2_ETHERNET
+	depends on NETWORKING
 	depends on !NET_TEST
+	default y if NET_L2_ETHERNET
 
 if ETH_DRIVER
 
+config ETH_DRIVER_RAW_MODE
+	bool "Ethernet driver without the MAC stack"
+	select NET_RAW_MODE
+	depends on !NET_L2_ETHERNET
+	help
+	  This option enables using the drivers in a so-called "raw" mode,
+	  i.e. without a MAC stack (the net L2 layer for ethernet will not
+	  be built).
+
 module = ETHERNET
 module-dep = LOG
 module-str = Log level for Ethernet driver
@@ -74,7 +83,7 @@ endif # "Ethernet Drivers"
 config ETH_INIT_PRIORITY
 	int "Ethernet driver init priority"
 	default 80
-	depends on NET_L2_ETHERNET
+	depends on NET_L2_ETHERNET || ETH_DRIVER
 	help
 	  Ethernet device driver initialization priority.
 	  Do not mess with it unless you know what you are doing.

drivers/ethernet/phy/Kconfig

@@ -3,8 +3,11 @@
 # Copyright (c) 2021 IP-Logix Inc.
 # SPDX-License-Identifier: Apache-2.0
 
-menu "Ethernet PHY Drivers"
-	depends on NET_L2_ETHERNET
+menuconfig ETH_PHY_DRIVER
+	bool "Ethernet PHY drivers"
+	default y if NET_L2_ETHERNET || ETH_DRIVER
+
+if ETH_PHY_DRIVER
 
 module = PHY
 module-dep = LOG
@@ -63,4 +66,4 @@ config PHY_MONITOR_PERIOD
 	  periodically executed to detect and report any changes in the
 	  PHY link status to the operating system.
 
-endmenu # "Ethernet PHY Drivers"
+endif # "Ethernet PHY Drivers"

drivers/net/Kconfig

@@ -153,7 +153,6 @@ config SLIP_STATISTICS
 config SLIP_TAP
 	bool "Use TAP interface to host"
 	default y
-	select NET_L2_ETHERNET
 	help
 	  In TAP the Ethernet frames are transferred over SLIP.
 

include/zephyr/net/ethernet.h

@@ -932,6 +932,7 @@ static inline bool net_eth_get_vlan_status(struct net_if *iface)
 }
 #endif
 
+#if !defined(CONFIG_ETH_DRIVER_RAW_MODE)
 #if defined(CONFIG_NET_VLAN)
 
 #define Z_ETH_NET_DEVICE_INIT_INSTANCE(node_id, dev_id, name, instance,	\
@@ -957,6 +958,17 @@ static inline bool net_eth_get_vlan_status(struct net_if *iface)
 				   NET_L2_GET_CTX_TYPE(ETHERNET_L2), mtu)
 #endif /* CONFIG_NET_VLAN */
 
+#else /* CONFIG_ETH_DRIVER_RAW_MODE */
+
+#define Z_ETH_NET_DEVICE_INIT_INSTANCE(node_id, dev_id, name, instance,	\
+				       init_fn, pm, data, config, prio,	\
+				       api, mtu)			\
+	Z_DEVICE_STATE_DEFINE(dev_id);					\
+	Z_DEVICE_DEFINE(node_id, dev_id, name, init_fn, pm, data,	\
+			config, POST_KERNEL, prio, api,			\
+			&Z_DEVICE_STATE_NAME(dev_id));
+#endif /* CONFIG_ETH_DRIVER_RAW_MODE */
+
 #define Z_ETH_NET_DEVICE_INIT(node_id, dev_id, name, init_fn, pm, data,	\
 			      config, prio, api, mtu)			\
 	Z_ETH_NET_DEVICE_INIT_INSTANCE(node_id, dev_id, name, 0,	\

subsys/net/ip/Kconfig

@@ -583,12 +583,6 @@ config NET_CONTEXT_RECV_PKTINFO
 	  This way user can get extra information about the received data in the
 	  socket.
 
-config NET_TEST
-	bool "Network Testing"
-	help
-	  Used for self-contained networking tests that do not require a
-	  network device.
-
 config NET_SLIP_TAP
 	bool "TAP SLIP driver"
 	depends on NET_QEMU_SLIP
@@ -606,6 +600,12 @@ config NET_SLIP_TAP
 
 endif # NET_RAW_MODE
 
+config NET_TEST
+	bool "Network Testing"
+	help
+	  Used for self-contained networking tests that do not require a
+	  network device.
+
 config NET_PKT_RX_COUNT
 	int "How many packet receives can be pending at the same time"
 	default 14 if NET_L2_ETHERNET