ARM: dts: mmp3: add Dell Wyse 3020 machine

This is a Dell Wyse thin client, variously referred to as "Ariel",
"3020" or "Tx0D" where "x" stands for the software it was shipped with.
I somewhat arbitrarily chose "ariel".

There are bits missing, because the drivers are not in and bindings are not
settled yet:

* Things missing from mmp3.dtsi:
  HSIC controller and its PHY (only the internal Ethernet is connected
  here, the hub with external USB2 ports is connected to the U2O controller
  that works well), Vivante GC2000 GPU

* &twsi1/regulator@19
  Marvell 88pm867 power regulator

* &twsi3/vga-dvi-encoder@76
  Chrontel CH7033B-BF VGA & DVI encoder

* &twsi3/sound-codec@30
  Sound chip, probably a Marvell 88ce156

* &twsi4/embedded-controller@58
  ENE KB3930QF Embedded Controller, also seems to be connected to &ssp4.
  Might not need a driver -- about the only useful thing it can do is to
  reboot the machine when tickled via some GPIO lines.

Also there seems to be something at &twsi1 address 0x50.

Link: https://lore.kernel.org/r/20191022152837.3553524-1-lkundrak@v3.skSigned-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/boot/dts/Makefile

@@ -337,7 +337,8 @@ dtb-$(CONFIG_ARCH_MMP) += \
 	pxa168-aspenite.dtb \
 	pxa910-dkb.dtb \
 	mmp2-brownstone.dtb \
-	mmp2-olpc-xo-1-75.dtb
+	mmp2-olpc-xo-1-75.dtb \
+	mmp3-dell-ariel.dtb
 dtb-$(CONFIG_ARCH_MPS2) += \
 	mps2-an385.dtb \
 	mps2-an399.dtb

arch/arm/boot/dts/mmp3-dell-ariel.dts

+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Dell Wyse 3020 a.k.a. "Ariel" a.k.a. Tx0D (T00D, T10D)
+ *
+ * Copyright (C) 2019 Lubomir Rintel <lkundrak@v3.sk>
+ */
+
+/dts-v1/;
+#include "mmp3.dtsi"
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+
+/ {
+	model = "Dell Ariel";
+	compatible = "dell,wyse-ariel", "marvell,mmp3";
+
+	chosen {
+		#address-cells = <0x1>;
+		#size-cells = <0x1>;
+		ranges;
+		bootargs = "earlyprintk=ttyS2,115200 console=ttyS2,115200";
+	};
+
+	memory {
+		linux,usable-memory = <0x0 0x7f600000>;
+		available = <0x7f700000 0x7ff00000 0x00000000 0x7f600000>;
+		reg = <0x0 0x80000000>;
+		device_type = "memory";
+	};
+};
+
+&uart3 {
+	status = "okay";
+};
+
+&rtc {
+	status = "okay";
+};
+
+&usb_otg0 {
+	status = "okay";
+};
+
+&usb_otg_phy0 {
+	status = "okay";
+};
+
+&mmc3 {
+	status = "okay";
+	max-frequency = <50000000>;
+	status = "okay";
+	bus-width = <8>;
+	non-removable;
+	cap-mmc-highspeed;
+};
+
+&twsi1 {
+	status = "okay";
+
+	rtc@68 {
+		compatible = "dallas,ds1338";
+		reg = <0x68>;
+		status = "okay";
+	};
+};
+
+&twsi3 {
+	status = "okay";
+};
+
+&twsi4 {
+	status = "okay";
+};
+
+&ssp3 {
+	status = "okay";
+	cs-gpios = <&gpio 46 GPIO_ACTIVE_HIGH>;
+
+	firmware-flash@0 {
+		compatible = "st,m25p80", "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <40000000>;
+		m25p,fast-read;
+	};
+};
+
+&ssp4 {
+	cs-gpios = <&gpio 56 GPIO_ACTIVE_HIGH>;
+	status = "okay";
+};