net: ethernet: rtsn: Add support for Renesas Ethernet-TSN

Add initial support for Renesas Ethernet-TSN End-station device of R-Car
V4H. The Ethernet End-station can connect to an Ethernet network using a
10 Mbps, 100 Mbps, or 1 Gbps full-duplex link via MII/GMII/RMII/RGMII.
Depending on the connected PHY.

The driver supports Rx checksum and offload and hardware timestamps.

While full power management and suspend/resume is not yet supported the
driver enables runtime PM in order to enable the module clock. While
explicit clock management using clk_enable() would suffice for the
supported SoC, the module could be reused on SoCs where the module is
part of a power domain.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -19032,6 +19032,14 @@ F:	drivers/net/ethernet/renesas/Makefile
 F:	drivers/net/ethernet/renesas/rcar_gen4*
 F:	drivers/net/ethernet/renesas/rswitch*
 
+RENESAS ETHERNET TSN DRIVER
+M:	Niklas Söderlund <niklas.soderlund@ragnatech.se>
+L:	netdev@vger.kernel.org
+L:	linux-renesas-soc@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/net/renesas,ethertsn.yaml
+F:	drivers/net/ethernet/renesas/rtsn.*
+
 RENESAS IDT821034 ASoC CODEC
 M:	Herve Codina <herve.codina@bootlin.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)

drivers/net/ethernet/renesas/Kconfig

@@ -59,4 +59,14 @@ config RENESAS_GEN4_PTP
 	help
 	  Renesas R-Car Gen4 gPTP device driver.
 
+config RTSN
+	tristate "Renesas Ethernet-TSN support"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	depends on PTP_1588_CLOCK
+	select CRC32
+	select PHYLIB
+	select RENESAS_GEN4_PTP
+	help
+	  Renesas Ethernet-TSN device driver.
+
 endif # NET_VENDOR_RENESAS

drivers/net/ethernet/renesas/Makefile

@@ -11,3 +11,5 @@ obj-$(CONFIG_RAVB) += ravb.o
 obj-$(CONFIG_RENESAS_ETHER_SWITCH) += rswitch.o
 
 obj-$(CONFIG_RENESAS_GEN4_PTP) += rcar_gen4_ptp.o
+
+obj-$(CONFIG_RTSN) += rtsn.o