net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver

Add Renesas RZ/N1 advanced 5 port switch driver. This switch handles 5
ports including 1 CPU management port. A MDIO bus is also exposed by
this switch and allows to communicate with PHYs connected to the ports.
Each switch port (except for the CPU management ports) is connected to
the MII converter.

This driver includes basic bridging support, more support will be added
later (vlan, etc).

Suggested-by: Jean-Pierre Geslin <jean-pierre.geslin@non.se.com>
Suggested-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/Kconfig

@@ -70,6 +70,15 @@ config NET_DSA_QCA8K
 
 source "drivers/net/dsa/realtek/Kconfig"
 
+config NET_DSA_RZN1_A5PSW
+	tristate "Renesas RZ/N1 A5PSW Ethernet switch support"
+	depends on OF && ARCH_RZN1
+	select NET_DSA_TAG_RZN1_A5PSW
+	select PCS_RZN1_MIIC
+	help
+	  This driver supports the A5PSW switch, which is embedded in Renesas
+	  RZ/N1 SoC.
+
 config NET_DSA_SMSC_LAN9303
 	tristate
 	select NET_DSA_TAG_LAN9303

drivers/net/dsa/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_NET_DSA_LANTIQ_GSWIP) += lantiq_gswip.o
 obj-$(CONFIG_NET_DSA_MT7530)	+= mt7530.o
 obj-$(CONFIG_NET_DSA_MV88E6060) += mv88e6060.o
 obj-$(CONFIG_NET_DSA_QCA8K)	+= qca8k.o
+obj-$(CONFIG_NET_DSA_RZN1_A5PSW) += rzn1_a5psw.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303) += lan9303-core.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303_I2C) += lan9303_i2c.o
 obj-$(CONFIG_NET_DSA_SMSC_LAN9303_MDIO) += lan9303_mdio.o