rockchip: rk3399: Add Nanopc T4 board support

Add initial support for Nanopc T4 board.

Specification
- Rockchip RK3399
- Dual-Channel 4GB LPDDR3-1866
- SD card slot
- 16GB eMMC
- RTL8211E 1Gbps
- AP6356S WiFI/BT
- HDMI In/Out, DP, MIPI DSI/CSI, eDP
- USB 3.0, 2.0
- USB Type C power and data
- GPIO expansion ports
- DC 12V/2A

Commit details of rk3399-nanopc-t4.dts sync from Linux 5.1-rc2:
"arm64: dts: rockchip: Add NanoPC-T4 IR receiver"
(sha1: 95658e21b1707ad7844f873db2fdaa295109a5a3)

Tested-by: Daniel Gröber <dxld@darkboxed.org>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index c77e763..75d4fda 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -106,6 +106,7 @@
 	rk3399-ficus.dtb \
 	rk3399-firefly.dtb \
 	rk3399-gru-bob.dtb \
+	rk3399-nanopc-t4.dtb \
 	rk3399-nanopi-m4.dtb \
 	rk3399-orangepi.dtb \
 	rk3399-puma-ddr1333.dtb \
diff --git a/arch/arm/dts/rk3399-nanopc-t4-u-boot.dtsi b/arch/arm/dts/rk3399-nanopc-t4-u-boot.dtsi
new file mode 100644
index 0000000..17201bc
--- /dev/null
+++ b/arch/arm/dts/rk3399-nanopc-t4-u-boot.dtsi
@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Jagan Teki <jagan@amarulasolutions.com>
+ */
+
+#include "rk3399-nanopi4-u-boot.dtsi"
+#include "rk3399-sdram-lpddr3-samsung-4GB-1866.dtsi"
diff --git a/arch/arm/dts/rk3399-nanopc-t4.dts b/arch/arm/dts/rk3399-nanopc-t4.dts
new file mode 100644
index 0000000..84433cf
--- /dev/null
+++ b/arch/arm/dts/rk3399-nanopc-t4.dts
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * FriendlyElec NanoPC-T4 board device tree source
+ *
+ * Copyright (c) 2018 FriendlyElec Computer Tech. Co., Ltd.
+ * (http://www.friendlyarm.com)
+ *
+ * Copyright (c) 2018 Collabora Ltd.
+ */
+
+/dts-v1/;
+#include "rk3399-nanopi4.dtsi"
+
+/ {
+	model = "FriendlyElec NanoPC-T4";
+	compatible = "friendlyarm,nanopc-t4", "rockchip,rk3399";
+
+	vcc12v0_sys: vcc12v0-sys {
+		compatible = "regulator-fixed";
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-max-microvolt = <12000000>;
+		regulator-min-microvolt = <12000000>;
+		regulator-name = "vcc12v0_sys";
+	};
+
+	vcc5v0_host0: vcc5v0-host0 {
+		compatible = "regulator-fixed";
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-name = "vcc5v0_host0";
+		vin-supply = <&vcc5v0_sys>;
+	};
+
+	adc-keys {
+		compatible = "adc-keys";
+		io-channels = <&saradc 1>;
+		io-channel-names = "buttons";
+		keyup-threshold-microvolt = <1800000>;
+		poll-interval = <100>;
+
+		recovery {
+			label = "Recovery";
+			linux,code = <KEY_VENDOR>;
+			press-threshold-microvolt = <18000>;
+		};
+	};
+
+	ir-receiver {
+		compatible = "gpio-ir-receiver";
+		gpios = <&gpio0 RK_PA6 GPIO_ACTIVE_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&ir_rx>;
+	};
+};
+
+&pinctrl {
+	ir {
+		ir_rx: ir-rx {
+			/* external pullup to VCC3V3_SYS, despite being 1.8V :/ */
+			rockchip,pins = <0 RK_PA6 RK_FUNC_1 &pcfg_pull_none>;
+		};
+	};
+};
+
+&sdhci {
+	mmc-hs400-1_8v;
+	mmc-hs400-enhanced-strobe;
+};
+
+&u2phy0_host {
+	phy-supply = <&vcc5v0_host0>;
+};
+
+&u2phy1_host {
+	phy-supply = <&vcc5v0_host0>;
+};
+
+&vcc5v0_sys {
+	vin-supply = <&vcc12v0_sys>;
+};
+
+&vcc3v3_sys {
+	vin-supply = <&vcc12v0_sys>;
+};
+
+&vbus_typec {
+	enable-active-high;
+	gpios = <&gpio4 RK_PD2 GPIO_ACTIVE_HIGH>;
+	vin-supply = <&vcc5v0_sys>;
+};