arm64: dts: qcom: Add device tree for Xiaomi Redmi 2 (wingtech-wt88047)

The Xiaomi Redmi 2 is a MSM8916 smartphone that was made by Wingtech
(codename: wt88047). It's fairly similar to the other MSM8916 devices.

The device tree contains initial support for the Xiaomi Redmi 2 with:
  - UART (untested, probably available via some test points)
  - eMMC/SD card
  - Buttons
  - Vibrator
  - WiFi/Bluetooth (WCNSS)
  - USB

Note that the Xiaomi Redmi 2 is available in variants with different
names (e.g. Redmi 2 Prime, Redmi 2 Pro, ...). As far as I know the main
difference between those is the amount of RAM and supported LTE bands.
This difference is automatically handled by bootloader/modem firmware
so there is no need for separate device trees.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210712133735.318250-1-stephan@gerhold.netSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/Makefile

@@ -15,6 +15,7 @@ dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-longcheer-l8910.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-mtp.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-samsung-a3u-eur.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-samsung-a5u-eur.dtb
+dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-wingtech-wt88047.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8992-bullhead-rev-101.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8992-msft-lumia-octagon-talkman.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8992-xiaomi-libra.dtb

arch/arm64/boot/dts/qcom/msm8916-wingtech-wt88047.dts

+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2020 Stephan Gerhold
+
+/dts-v1/;
+
+#include "msm8916-pm8916.dtsi"
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	model = "Xiaomi Redmi 2 (Wingtech WT88047)";
+	compatible = "wingtech,wt88047", "qcom,msm8916";
+
+	aliases {
+		serial0 = &blsp1_uart2;
+	};
+
+	chosen {
+		stdout-path = "serial0";
+	};
+
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&gpio_keys_default>;
+
+		label = "GPIO Buttons";
+
+		volume-up {
+			label = "Volume Up";
+			gpios = <&msmgpio 107 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_VOLUMEUP>;
+		};
+	};
+
+	usb_id: usb-id {
+		compatible = "linux,extcon-usb-gpio";
+		id-gpio = <&msmgpio 110 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&usb_id_default>;
+	};
+};
+
+&blsp1_uart2 {
+	status = "okay";
+};
+
+&pm8916_resin {
+	status = "okay";
+	linux,code = <KEY_VOLUMEDOWN>;
+};
+
+&pm8916_vib {
+	status = "okay";
+};
+
+&pronto {
+	status = "okay";
+};
+
+&sdhc_1 {
+	status = "okay";
+
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&sdc1_clk_on &sdc1_cmd_on &sdc1_data_on>;
+	pinctrl-1 = <&sdc1_clk_off &sdc1_cmd_off &sdc1_data_off>;
+};
+
+&sdhc_2 {
+	status = "okay";
+
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&sdc2_clk_on &sdc2_cmd_on &sdc2_data_on>;
+	pinctrl-1 = <&sdc2_clk_off &sdc2_cmd_off &sdc2_data_off>;
+
+	non-removable;
+};
+
+&usb {
+	status = "okay";
+	extcon = <&usb_id>, <&usb_id>;
+};
+
+&usb_hs_phy {
+	extcon = <&usb_id>;
+};
+
+&smd_rpm_regulators {
+	vdd_l1_l2_l3-supply = <&pm8916_s3>;
+	vdd_l4_l5_l6-supply = <&pm8916_s4>;
+	vdd_l7-supply = <&pm8916_s4>;
+
+	s3 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <1300000>;
+	};
+
+	s4 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <2100000>;
+	};
+
+	l1 {
+		regulator-min-microvolt = <1225000>;
+		regulator-max-microvolt = <1225000>;
+	};
+
+	l2 {
+		regulator-min-microvolt = <1200000>;
+		regulator-max-microvolt = <1200000>;
+	};
+
+	l4 {
+		regulator-min-microvolt = <2050000>;
+		regulator-max-microvolt = <2050000>;
+	};
+
+	l5 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+	};
+
+	l6 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+	};
+
+	l7 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+	};
+
+	l8 {
+		regulator-min-microvolt = <2850000>;
+		regulator-max-microvolt = <2900000>;
+	};
+
+	l9 {
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	l10 {
+		regulator-min-microvolt = <2700000>;
+		regulator-max-microvolt = <2800000>;
+	};
+
+	l11 {
+		regulator-min-microvolt = <2950000>;
+		regulator-max-microvolt = <2950000>;
+		regulator-allow-set-load;
+		regulator-system-load = <200000>;
+	};
+
+	l12 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <2950000>;
+	};
+
+	l13 {
+		regulator-min-microvolt = <3075000>;
+		regulator-max-microvolt = <3075000>;
+	};
+
+	l14 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	l15 {
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	l16 {
+		regulator-min-microvolt = <2800000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	l17 {
+		regulator-min-microvolt = <2850000>;
+		regulator-max-microvolt = <2850000>;
+	};
+
+	l18 {
+		regulator-min-microvolt = <2700000>;
+		regulator-max-microvolt = <2700000>;
+	};
+};
+
+&msmgpio {
+	gpio_keys_default: gpio-keys-default {
+		pins = "gpio107";
+		function = "gpio";
+
+		drive-strength = <2>;
+		bias-pull-up;
+	};
+
+	usb_id_default: usb-id-default {
+		pins = "gpio110";
+		function = "gpio";
+
+		drive-strength = <8>;
+		bias-pull-up;
+	};
+};