The 100ask Dongshan Nezha STU is a system-on-module that can be used
standalone or with a carrier board. The SoM provides gigabit Ethernet,
HDMI, a USB peripheral port, and WiFi/Bluetooth via an RTL8723DS chip.

The "DIY" carrier board exposes almost every pin from the D1 SoC to 0.1"
headers, but contains no digital circuitry, so it does not have its own
devicetree.

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
---

(no changes since v3)

Changes in v3:
 - Drop mmc alias

 arch/riscv/boot/dts/allwinner/Makefile        |   1 +
 .../sun20i-d1-dongshan-nezha-stu.dts          | 117 ++++++++++++++++++
 2 files changed, 118 insertions(+)
 create mode 100644 arch/riscv/boot/dts/allwinner/sun20i-d1-dongshan-nezha-stu.dts

diff --git a/arch/riscv/boot/dts/allwinner/Makefile b/arch/riscv/boot/dts/allwinner/Makefile
index 2ed586fafaea..87f70b1af6b4 100644
--- a/arch/riscv/boot/dts/allwinner/Makefile
+++ b/arch/riscv/boot/dts/allwinner/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
+dtb-$(CONFIG_ARCH_SUNXI) += sun20i-d1-dongshan-nezha-stu.dtb
 dtb-$(CONFIG_ARCH_SUNXI) += sun20i-d1-lichee-rv-86-panel-480p.dtb
 dtb-$(CONFIG_ARCH_SUNXI) += sun20i-d1-lichee-rv-86-panel-720p.dtb
 dtb-$(CONFIG_ARCH_SUNXI) += sun20i-d1-lichee-rv-dock.dtb
diff --git a/arch/riscv/boot/dts/allwinner/sun20i-d1-dongshan-nezha-stu.dts b/arch/riscv/boot/dts/allwinner/sun20i-d1-dongshan-nezha-stu.dts
new file mode 100644
index 000000000000..8785de3c9224
--- /dev/null
+++ b/arch/riscv/boot/dts/allwinner/sun20i-d1-dongshan-nezha-stu.dts
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: (GPL-2.0+ or MIT)
+// Copyright (C) 2022 Samuel Holland <samuel@sholland.org>
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/leds/common.h>
+
+/dts-v1/;
+
+#include "sun20i-d1.dtsi"
+#include "sun20i-common-regulators.dtsi"
+
+/ {
+	model = "Dongshan Nezha STU";
+	compatible = "100ask,dongshan-nezha-stu", "allwinner,sun20i-d1";
+
+	aliases {
+		ethernet0 = &emac;
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led-0 {
+			color = <LED_COLOR_ID_GREEN>;
+			function = LED_FUNCTION_STATUS;
+			gpios = <&pio 2 1 GPIO_ACTIVE_HIGH>; /* PC1 */
+		};
+	};
+
+	reg_usbvbus: usbvbus {
+		compatible = "regulator-fixed";
+		regulator-name = "usbvbus";
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+		gpio = <&pio 3 19 GPIO_ACTIVE_HIGH>; /* PD19 */
+		enable-active-high;
+		vin-supply = <&reg_vcc>;
+	};
+
+	/*
+	 * This regulator is PWM-controlled, but the PWM controller is not
+	 * yet supported, so fix the regulator to its default voltage.
+	 */
+	reg_vdd_cpu: vdd-cpu {
+		compatible = "regulator-fixed";
+		regulator-name = "vdd-cpu";
+		regulator-min-microvolt = <1100000>;
+		regulator-max-microvolt = <1100000>;
+		vin-supply = <&reg_vcc>;
+	};
+};
+
+&cpu0 {
+	cpu-supply = <&reg_vdd_cpu>;
+};
+
+&dcxo {
+	clock-frequency = <24000000>;
+};
+
+&ehci0 {
+	status = "okay";
+};
+
+&emac {
+	pinctrl-0 = <&rgmii_pe_pins>;
+	pinctrl-names = "default";
+	phy-handle = <&ext_rgmii_phy>;
+	phy-mode = "rgmii-id";
+	phy-supply = <&reg_vcc_3v3>;
+	status = "okay";
+};
+
+&mdio {
+	ext_rgmii_phy: ethernet-phy@1 {
+		compatible = "ethernet-phy-ieee802.3-c22";
+		reg = <1>;
+	};
+};
+
+&mmc0 {
+	broken-cd;
+	bus-width = <4>;
+	disable-wp;
+	vmmc-supply = <&reg_vcc_3v3>;
+	vqmmc-supply = <&reg_vcc_3v3>;
+	pinctrl-0 = <&mmc0_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&ohci0 {
+	status = "okay";
+};
+
+&uart0 {
+	pinctrl-0 = <&uart0_pb8_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&usb_otg {
+	dr_mode = "otg";
+	status = "okay";
+};
+
+&usbphy {
+	usb0_id_det-gpios = <&pio 3 21 GPIO_ACTIVE_HIGH>; /* PD21 */
+	usb0_vbus_det-gpios = <&pio 3 20 GPIO_ACTIVE_HIGH>; /* PD20 */
+	usb0_vbus-supply = <&reg_usbvbus>;
+	status = "okay";
+};
-- 
2.37.4