net: ethernet: renesas: Add support for "Ethernet Switch"

Add initial support for Renesas "Ethernet Switch" device of R-Car S4-8.
The hardware has features about forwarding for an ethernet switch
device. But, for now, it acts as ethernet controllers so that any
forwarding offload features are not supported. So, any switchdev
header files and DSA framework are not used.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/Kconfig

@@ -42,4 +42,15 @@ config RAVB
 	  This driver supports the following SoCs:
 		- R8A779x.
 
+config RENESAS_ETHER_SWITCH
+	tristate "Renesas Ethernet Switch support"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select CRC32
+	select MII
+	select PHYLINK
+	help
+	  Renesas Ethernet Switch device driver.
+	  This driver supports the following SoCs:
+		- R8A779Fx.
+
 endif # NET_VENDOR_RENESAS

drivers/net/ethernet/renesas/Makefile

@@ -8,3 +8,7 @@ obj-$(CONFIG_SH_ETH) += sh_eth.o
 ravb-objs := ravb_main.o ravb_ptp.o
 
 obj-$(CONFIG_RAVB) += ravb.o
+
+rswitch_drv-objs := rswitch.o
+
+obj-$(CONFIG_RENESAS_ETHER_SWITCH) += rswitch_drv.o