ARM: sun8i: Introduce A23 Evaluation Board Support

The A23 Evaluation Board has an MMC slot, two UARTs, NAND, a few display
connectors (RGB, MIPI, LVDS), a mini-PCIE slot, USB host and OTG and a
bunch of embedded sensors.

Signed-off-by: Maxime Ripard <[e-mail]>

arch/arm/boot/dts/Makefile

···
 	sun7i-a20-pcduino3-nano.dtb \
 	sun7i-a20-wexler-tab7200.dtb
 dtb-$(CONFIG_MACH_SUN8I) += \
+	sun8i-a23-evb.dtb \
 	sun8i-a23-ippo-q8h-v5.dtb \
 	sun8i-a23-ippo-q8h-v1.2.dtb
 dtb-$(CONFIG_MACH_SUN9I) += \

arch/arm/boot/dts/sun8i-a23-evb.dts

···
+/*
+ * Copyright 2015 Maxime Ripard
+ *
+ * Maxime Ripard <[e-mail]>
+ *
+ * This file is dual-licensed: you can use it either under the terms
+ * of the GPL or the X11 license, at your option. Note that this dual
+ * licensing only applies to this file, and not this project as a
+ * whole.
+ *
+ *  a) This file is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License as
+ *     published by the Free Software Foundation; either version 2 of the
+ *     License, or (at your option) any later version.
+ *
+ *     This file is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ * Or, alternatively,
+ *
+ *  b) Permission is hereby granted, free of charge, to any person
+ *     obtaining a copy of this software and associated documentation
+ *     files (the "Software"), to deal in the Software without
+ *     restriction, including without limitation the rights to use,
+ *     copy, modify, merge, publish, distribute, sublicense, and/or
+ *     sell copies of the Software, and to permit persons to whom the
+ *     Software is furnished to do so, subject to the following
+ *     conditions:
+ *
+ *     The above copyright notice and this permission notice shall be
+ *     included in all copies or substantial portions of the Software.
+ *
+ *     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *     OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *     OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/dts-v1/;
+#include "sun8i-a23.dtsi"
+#include "sunxi-common-regulators.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/pinctrl/sun4i-a10.h>
+
+/ {
+	model = "Allwinner A23 Evaluation Board";
+	compatible = "allwinner,sun8i-a23-evb", "allwinner,sun8i-a23";
+
+	aliases {
+		i2c0 = &i2c0;
+		i2c1 = &i2c1;
+		serial0 = &r_uart;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+};
+
+&i2c0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c0_pins_a>;
+	status = "okay";
+};
+
+&i2c1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c1_pins_a>;
+	status = "okay";
+};
+
+&lradc {
+	vref-supply = <&reg_vcc3v0>;
+	status = "okay";
+
+	button@190 {
+		label = "Volume Up";
+		linux,code = <KEY_VOLUMEUP>;
+		channel = <0>;
+		voltage = <190000>;
+	};
+
+	button@390 {
+		label = "Volume Down";
+		linux,code = <KEY_VOLUMEDOWN>;
+		channel = <0>;
+		voltage = <390000>;
+	};
+
+	button@600 {
+		label = "Home";
+		linux,code = <KEY_HOME>;
+		channel = <0>;
+		voltage = <600000>;
+	};
+};
+
+&mmc0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&mmc0_pins_a>, <&mmc0_cd_pin_evb>;
+	vmmc-supply = <&reg_vcc3v0>;
+	bus-width = <4>;
+	cd-gpios = <&pio 1 4 GPIO_ACTIVE_HIGH>; /* PB4 */
+	cd-inverted;
+	status = "okay";
+};
+
+&pio {
+	mmc0_cd_pin_evb: mmc0_cd_pin@0 {
+		allwinner,pins = "PB4";
+		allwinner,function = "gpio_in";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
+	};
+};
+
+/*
+ * The RX line has a non-populated resistance. In order to use it, you
+ * need to solder R207 on the back of the board in order to close the
+ * line and get a working UART.
+ */
+&r_uart {
+	pinctrl-names = "default";
+	pinctrl-0 = <&r_uart_pins_a>;
+	status = "okay";
+};