ARM: dts: rockchip: Enable WiFi on rk3288-tinker

This patch adds wifi support to the ASUS Tinker Board (S) machines.

This is provided by an wifi card (RTL8723BS) wired into the sdio interface.

It requires certain pins pulled, to enable the WiFi.

The schematics for these board do not show the WiFi connection, so the
connections have been taken from:

https://github.com/TinkerBoard/debian_kernel/blob/develop/arch/arm/boot/dts/rk3288-miniarm.dts

In particular the pulling of two pins.
Co-developed-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David Summers <beagleboard@davidjohnsummers.uk>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Tony McKahan <tonymckahan@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3288-tinker.dtsi

@@ -5,6 +5,7 @@
 
 #include "rk3288.dtsi"
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/clock/rockchip,rk808.h>
 
 / {
 	chosen {
@@ -61,6 +62,16 @@ pwr-led {
 		};
 	};
 
+	sdio_pwrseq: sdio-pwrseq {
+		compatible = "mmc-pwrseq-simple";
+		clocks = <&rk808 RK808_CLKOUT1>;
+		clock-names = "ext_clock";
+		pinctrl-names = "default";
+		pinctrl-0 = <&wifi_enable>;
+		reset-gpios = <&gpio4 RK_PD3 GPIO_ACTIVE_LOW>,
+			<&gpio4 RK_PD4 GPIO_ACTIVE_LOW>;
+	};
+
 	sound {
 		compatible = "simple-audio-card";
 		simple-audio-card,format = "i2s";
@@ -337,6 +348,7 @@ &io_domains {
 	status = "okay";
 
 	sdcard-supply = <&vccio_sd>;
+	wifi-supply = <&vcc_18>;
 };
 
 &pinctrl {
@@ -415,6 +427,13 @@ pwr_3g: pwr-3g {
 			rockchip,pins = <7 8 RK_FUNC_GPIO &pcfg_pull_none>;
 		};
 	};
+
+	sdio {
+		wifi_enable: wifi-enable {
+			rockchip,pins = <4 RK_PD3 RK_FUNC_GPIO &pcfg_pull_none>,
+				<4 RK_PD4 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
 };
 
 &pwm0 {
@@ -439,6 +458,24 @@ &sdmmc {
 	vqmmc-supply = <&vccio_sd>;
 };
 
+&sdio0 {
+	bus-width = <4>;
+	cap-sd-highspeed;
+	cap-sdio-irq;
+	keep-power-in-suspend;
+	max-frequency = <50000000>;
+	mmc-pwrseq = <&sdio_pwrseq>;
+	non-removable;
+	pinctrl-names = "default";
+	pinctrl-0 = <&sdio0_bus4>, <&sdio0_cmd>, <&sdio0_clk>, <&sdio0_int>;
+	sd-uhs-sdr12;
+	sd-uhs-sdr25;
+	sd-uhs-sdr50;
+	vmmc-supply = <&vcc_io>;
+	vqmmc-supply = <&vcc_18>;
+	status = "okay";
+};
+
 &tsadc {
 	rockchip,hw-tshut-mode = <1>; /* tshut mode 0:CRU 1:GPIO */
 	rockchip,hw-tshut-polarity = <1>; /* tshut polarity 0:LOW 1:HIGH */