ARM: dts: Add Raspberry Pi Zero 2 W

The Raspberry Pi Zero 2 W mostly bases on the Raspberry Pi Zero W with
the following differences:
* Broadcom BCM2710A1, quad-core 64-bit SoC @ 1 GHz
* Synaptics BCM43436 (reported as BCM43430B0) IEEE 802.11b/g/n wireless LAN

Contrary to the Raspberry Pi 3 boards there is no GPIO expander.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/Makefile

@@ -93,6 +93,7 @@ dtb-$(CONFIG_ARCH_BCM2835) += \
 	bcm2837-rpi-3-b.dtb \
 	bcm2837-rpi-3-b-plus.dtb \
 	bcm2837-rpi-cm3-io3.dtb \
+	bcm2837-rpi-zero-2-w.dtb \
 	bcm2711-rpi-400.dtb \
 	bcm2711-rpi-4-b.dtb \
 	bcm2711-rpi-cm4-io.dtb \

arch/arm/boot/dts/bcm2837-rpi-zero-2-w.dts

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Stefan Wahren <stefan.wahren@i2se.com>
+ */
+
+/dts-v1/;
+#include "bcm2837.dtsi"
+#include "bcm2836-rpi.dtsi"
+#include "bcm283x-rpi-usb-otg.dtsi"
+#include "bcm283x-rpi-wifi-bt.dtsi"
+
+/ {
+	compatible = "raspberrypi,model-zero-2-w", "brcm,bcm2837";
+	model = "Raspberry Pi Zero 2 W";
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0 0x20000000>;
+	};
+
+	chosen {
+		/* 8250 auxiliary UART instead of pl011 */
+		stdout-path = "serial1:115200n8";
+	};
+
+	leds {
+		led-act {
+			gpios = <&gpio 29 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&bt {
+	shutdown-gpios = <&gpio 42 GPIO_ACTIVE_HIGH>;
+};
+
+&gpio {
+	/*
+	 * This is based on the official GPU firmware DT blob.
+	 *
+	 * Legend:
+	 * "NC" = not connected (no rail from the SoC)
+	 * "FOO" = GPIO line named "FOO" on the schematic
+	 * "FOO_N" = GPIO line named "FOO" on schematic, active low
+	 */
+	gpio-line-names = "ID_SDA",
+			  "ID_SCL",
+			  "SDA1",
+			  "SCL1",
+			  "GPIO_GCLK",
+			  "GPIO5",
+			  "GPIO6",
+			  "SPI_CE1_N",
+			  "SPI_CE0_N",
+			  "SPI_MISO",
+			  "SPI_MOSI",
+			  "SPI_SCLK",
+			  "GPIO12",
+			  "GPIO13",
+			  /* Serial port */
+			  "TXD0",
+			  "RXD0",
+			  "GPIO16",
+			  "GPIO17",
+			  "GPIO18",
+			  "GPIO19",
+			  "GPIO20",
+			  "GPIO21",
+			  "GPIO22",
+			  "GPIO23",
+			  "GPIO24",
+			  "GPIO25",
+			  "GPIO26",
+			  "GPIO27",
+			  "HDMI_HPD_N",
+			  "STATUS_LED_N",
+			  "NC", /* GPIO30 */
+			  "NC", /* GPIO31 */
+			  "NC", /* GPIO32 */
+			  "NC", /* GPIO33 */
+			  "NC", /* GPIO34 */
+			  "NC", /* GPIO35 */
+			  "NC", /* GPIO36 */
+			  "NC", /* GPIO37 */
+			  "NC", /* GPIO38 */
+			  "NC", /* GPIO39 */
+			  "CAM_GPIO0", /* GPIO40 */
+			  "WL_ON", /* GPIO41 */
+			  "BT_ON", /* GPIO42 */
+			  "WIFI_CLK", /* GPIO43 */
+			  "SDA0", /* GPIO44 */
+			  "SCL0", /* GPIO45 */
+			  "SMPS_SCL",
+			  "SMPS_SDA",
+			  /* Used by SD Card */
+			  "SD_CLK_R",
+			  "SD_CMD_R",
+			  "SD_DATA0_R",
+			  "SD_DATA1_R",
+			  "SD_DATA2_R",
+			  "SD_DATA3_R";
+
+	pinctrl-0 = <&gpioout &alt0>;
+};
+
+&hdmi {
+	hpd-gpios = <&gpio 28 GPIO_ACTIVE_LOW>;
+	power-domains = <&power RPI_POWER_DOMAIN_HDMI>;
+	status = "okay";
+};
+
+&sdhci {
+	pinctrl-0 = <&emmc_gpio34 &gpclk2_gpio43>;
+};
+
+&sdhost {
+	pinctrl-names = "default";
+	pinctrl-0 = <&sdhost_gpio48>;
+	bus-width = <4>;
+	status = "okay";
+};
+
+&uart0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart0_gpio32 &uart0_ctsrts_gpio30>;
+};
+
+&uart1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart1_gpio14>;
+	status = "okay";
+};
+
+&wifi_pwrseq {
+	reset-gpios = <&gpio 41 GPIO_ACTIVE_LOW>;
+};