rockchip: rk3399: Add Nanopi M4 2GB board support

commit b2f5da9dd068 ("rockchip: rk3399: Add Nanopi M4 board support") added
support for Nanopi M4 board with Dual-Channel 4GB LPDDR3-1866 RAM.
This patch adds another variant of NanoPi M4 board with Dual-Channel
2GB DDR3-1866 RAM.

Signed-off-by: Deepak Das <deepakdas.linux@gmail.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index e1be8b4..23aa125 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -126,6 +126,7 @@
 	rk3399-leez-p710.dtb \
 	rk3399-nanopc-t4.dtb \
 	rk3399-nanopi-m4.dtb \
+	rk3399-nanopi-m4-2gb.dtb \
 	rk3399-nanopi-neo4.dtb \
 	rk3399-orangepi.dtb \
 	rk3399-puma-ddr1333.dtb \
diff --git a/arch/arm/dts/rk3399-nanopi-m4-2gb-u-boot.dtsi b/arch/arm/dts/rk3399-nanopi-m4-2gb-u-boot.dtsi
new file mode 100644
index 0000000..a2f9786
--- /dev/null
+++ b/arch/arm/dts/rk3399-nanopi-m4-2gb-u-boot.dtsi
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Jagan Teki <jagan@amarulasolutions.com>
+ * Copyright (C) 2020 Deepak Das <deepakdas.linux@gmail.com>
+ */
+
+#include "rk3399-nanopi4-u-boot.dtsi"
+#include "rk3399-sdram-ddr3-1866.dtsi"
diff --git a/arch/arm/dts/rk3399-nanopi-m4-2gb.dts b/arch/arm/dts/rk3399-nanopi-m4-2gb.dts
new file mode 100644
index 0000000..60358ab
--- /dev/null
+++ b/arch/arm/dts/rk3399-nanopi-m4-2gb.dts
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * FriendlyElec NanoPi M4 board device tree source
+ *
+ * Copyright (c) 2018 FriendlyElec Computer Tech. Co., Ltd.
+ * (http://www.friendlyarm.com)
+ *
+ * Copyright (c) 2018 Collabora Ltd.
+ * Copyright (c) 2019 Arm Ltd.
+ */
+
+/dts-v1/;
+#include "rk3399-nanopi4.dtsi"
+
+/ {
+	model = "FriendlyElec NanoPi M4";
+	compatible = "friendlyarm,nanopi-m4", "rockchip,rk3399";
+
+	vdd_5v: vdd-5v {
+		compatible = "regulator-fixed";
+		regulator-name = "vdd_5v";
+		regulator-always-on;
+		regulator-boot-on;
+	};
+
+	vcc5v0_core: vcc5v0-core {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc5v0_core";
+		regulator-always-on;
+		regulator-boot-on;
+		vin-supply = <&vdd_5v>;
+	};
+
+	vcc5v0_usb1: vcc5v0-usb1 {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc5v0_usb1";
+		regulator-always-on;
+		regulator-boot-on;
+		vin-supply = <&vcc5v0_sys>;
+	};
+
+	vcc5v0_usb2: vcc5v0-usb2 {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc5v0_usb2";
+		regulator-always-on;
+		regulator-boot-on;
+		vin-supply = <&vcc5v0_sys>;
+	};
+};
+
+&vcc3v3_sys {
+	vin-supply = <&vcc5v0_core>;
+};
+
+&u2phy0_host {
+	phy-supply = <&vcc5v0_usb1>;
+};
+
+&u2phy1_host {
+	phy-supply = <&vcc5v0_usb2>;
+};
+
+&vbus_typec {
+	regulator-always-on;
+	vin-supply = <&vdd_5v>;
+};