ARM: dts: Add devicetree for Supermicro X9SCi-LN4F based on WPCM450

The Supermicro X9SCi-LN4F is a server mainboard featuring the WPCM450
BMC. This patch adds a minimal devicetree for Linux running on the BMC.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210406120921.2484986-10-j.neuschaefer@gmx.net
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/Makefile

@@ -333,6 +333,8 @@ dtb-$(CONFIG_ARCH_LPC18XX) += \
 dtb-$(CONFIG_ARCH_LPC32XX) += \
 	lpc3250-ea3250.dtb \
 	lpc3250-phy3250.dtb
+dtb-$(CONFIG_ARCH_WPCM450) += \
+	nuvoton-wpcm450-supermicro-x9sci-ln4f.dtb
 dtb-$(CONFIG_ARCH_NPCM7XX) += \
 	nuvoton-npcm730-gsj.dtb \
 	nuvoton-npcm730-kudo.dtb \

arch/arm/boot/dts/nuvoton-wpcm450-supermicro-x9sci-ln4f.dts

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+// Copyright 2021 Jonathan Neuschäfer
+
+/dts-v1/;
+
+/* The last 16 MiB are dedicated to the GPU */
+/memreserve/ 0x07000000 0x01000000;
+
+#include "nuvoton-wpcm450.dtsi"
+
+/ {
+	model = "Supermicro X9SCi-LN4F BMC";
+	compatible = "supermicro,x9sci-ln4f-bmc", "nuvoton,wpcm450";
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0 0x08000000>; /* 128 MiB */
+	};
+};
+
+&serial0 {
+	/*
+	 * Debug serial port. TX is exposed on the right pad of unpopulated
+	 * resistor R1247, RX on the right pad of R1162.
+	 */
+	status = "okay";
+};
+
+&serial1 {
+	/* "Serial over LAN" port. Connected to ttyS2 of the host system. */
+	status = "okay";
+};
+
+&watchdog0 {
+	status = "okay";
+};