[RFC PATCH 3/3] arm64: dts: ti: k3-j784s4: Add overlay for dual port USXGMII mode

[Siddharth Vadapalli]

The CPSW9G instance of the CPSW Ethernet Switch supports USXGMII mode
with MAC Ports 1 and 2 of the instance, which are connected to ENET
Expansion 1 and ENET Expansion 2 slots on the EVM respectively, through
the Serdes2 instance of the SERDES.

Enable CPSW9G MAC Ports 1 and 2 in fixed-link configuration USXGMII mode
at 5 Gbps each.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>
---
 arch/arm64/boot/dts/ti/Makefile               |  1 +
 .../ti/k3-j784s4-evm-usxgmii-exp1-exp2.dtso   | 72 +++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 arch/arm64/boot/dts/ti/k3-j784s4-evm-usxgmii-exp1-exp2.dtso

diff --git a/arch/arm64/boot/dts/ti/Makefile b/arch/arm64/boot/dts/ti/Makefile
index 88c43f1f211b..8ac7507f60ba 100644
--- a/arch/arm64/boot/dts/ti/Makefile
+++ b/arch/arm64/boot/dts/ti/Makefile
@@ -47,6 +47,7 @@ dtb-$(CONFIG_ARCH_K3) += k3-j721s2-common-proc-board.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am69-sk.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-j784s4-evm.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-j784s4-evm-quad-port-eth-exp1.dtbo
+dtb-$(CONFIG_ARCH_K3) += k3-j784s4-evm-usxgmii-exp1-exp2.dtbo
 
 # Enable support for device-tree overlays
 DTC_FLAGS_k3-am6548-iot2050-advanced-m2 += -@
diff --git a/arch/arm64/boot/dts/ti/k3-j784s4-evm-usxgmii-exp1-exp2.dtso b/arch/arm64/boot/dts/ti/k3-j784s4-evm-usxgmii-exp1-exp2.dtso
new file mode 100644
index 000000000000..90f045a6a9ad
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-j784s4-evm-usxgmii-exp1-exp2.dtso
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * DT Overlay for CPSW9G in dual port fixed-link USXGMII mode using ENET-1
+ * and ENET-2 Expansion slots of J784S4 EVM.
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/mux/ti-serdes.h>
+#include <dt-bindings/phy/phy-cadence.h>
+#include <dt-bindings/phy/phy.h>
+
+&main_cpsw0 {
+	status = "okay";
+	pinctrl-names = "default";
+};
+
+&main_cpsw0_port1 {
+	status = "okay";
+	phy-mode = "usxgmii";
+	mac-address = [00 00 00 00 00 00];
+	phys = <&cpsw0_phy_gmii_sel 1>, <&serdes2_usxgmii_link>;
+	phy-names = "mac", "serdes";
+	fixed-link {
+		speed = <5000>;
+		full-duplex;
+	};
+};
+
+&main_cpsw0_port2 {
+	status = "okay";
+	phy-mode = "usxgmii";
+	mac-address = [00 00 00 00 00 00];
+	phys = <&cpsw0_phy_gmii_sel 2>, <&serdes2_usxgmii_link>;
+	phy-names = "mac", "serdes";
+	fixed-link {
+		speed = <5000>;
+		full-duplex;
+	};
+};
+
+&serdes_wiz2 {
+	status = "okay";
+	assigned-clock-parents = <&k3_clks 406 9>;
+};
+
+&serdes2 {
+	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	serdes2_usxgmii_link: phy@2 {
+		reg = <2>;
+		cdns,num-lanes = <2>;
+		#phy-cells = <0>;
+		cdns,phy-type = <PHY_TYPE_USXGMII>;
+		resets = <&serdes_wiz2 3>, <&serdes_wiz2 4>;
+	};
+};
+
+&serdes_ln_ctrl {
+	idle-states = <J784S4_SERDES0_LANE0_PCIE1_LANE0>, <J784S4_SERDES0_LANE1_PCIE1_LANE1>,
+		      <J784S4_SERDES0_LANE2_IP3_UNUSED>, <J784S4_SERDES0_LANE3_USB>,
+		      <J784S4_SERDES1_LANE0_PCIE0_LANE0>, <J784S4_SERDES1_LANE1_PCIE0_LANE1>,
+		      <J784S4_SERDES1_LANE2_PCIE0_LANE2>, <J784S4_SERDES1_LANE3_PCIE0_LANE3>,
+		      <J784S4_SERDES2_LANE0_IP2_UNUSED>, <J784S4_SERDES2_LANE1_IP2_UNUSED>,
+		      <J784S4_SERDES2_LANE2_QSGMII_LANE1>, <J784S4_SERDES2_LANE3_QSGMII_LANE2>;
+};
-- 
2.25.1