[PATCH 2/3] ARM: dts: rk3288 Tinker Board (S) add wi-fi

[David Summers <beagleboard@davidjohnsummers.uk>]

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

Unfortunatly neither the Tinker Board nor the Tinker Board S schematic
indicate how the WiFi is wired up on these devices. The WiFi is
provided by the RTL8723BS device, that has sdio WiFi and UART
Bluetooth. This patch just adds the WiFi interface.

With no schematic, most of the wiring has been derived from the ASUS
patch to Debian:

https://github.com/TinkerBoard/debian_kernel/commit/6a3128ade33f758887048578ada61a4b7ab8e678

In conjunction with the pin out of the RTL8723BS device:

http://files.pine64.org/doc/datasheet/pine64/RTL8723BS.pdf
http://cit.odessa.ua/media/pdf/Intel-Compute-Stick/FN-Link_F23BDSM25-W1.pdf

The only unusual part is that to bring the card up, both the pins
RK_PD3 and RK_PD4 need to be pulled. Why this needs to be done is not
clear, best explaination is that they are connected to the RTL8723BS
pins WL_DIS# and BT_DIS#, which the data sheet vaguely says:

Shared with GPIO9 This Pin Can Externally Shutdown the RTL8723BS WLAN
function when BT_DISn is Pulled Low. When this pin deasserted, SDIO
interface will be disabled. This pin can also support the WLAN Ra
dio-off function with host interface remaining connected.

Anyway extensive testing the TheSaint on ArchLinux Arm Forum 

https://archlinuxarm.org/forum/viewtopic.php?f=44&t=13064&start=120#p60548

Signed-off-by: David Summers <beagleboard@davidjohnsummers.uk>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 arch/arm/boot/dts/rk3288-tinker.dtsi | 39 +++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi
index fceaeed44e34..e1796f340eef 100644
--- a/arch/arm/boot/dts/rk3288-tinker.dtsi
+++ b/arch/arm/boot/dts/rk3288-tinker.dtsi
@@ -3,8 +3,9 @@
  * Copyright (c) 2017 Fuzhou Rockchip Electronics Co., Ltd.
  */
 
 #include "rk3288.dtsi"
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/clock/rockchip,rk808.h>
 
 / {
 	chosen {
@@ -98,6 +97,15 @@
 		startup-delay-us = <100000>;
 		vin-supply = <&vcc_io>;
 	};
+
+	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>;
+	};
 };
 
 &cpu0 {
@@ -337,8 +345,8 @@
 
 &io_domains {
 	status = "okay";
-
 	sdcard-supply = <&vccio_sd>;
+	wifi-supply = <&vcc_18>;
 };
 
 &pinctrl {
@@ -417,6 +425,12 @@
 			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 {
@@ -440,6 +454,25 @@
 	vqmmc-supply = <&vccio_sd>;
 };
 
+&sdio0 {
+	bus-width = <4>;
+	cap-sd-highspeed;
+	cap-sdio-irq;
+	keep-power-in-suspend;
+	mmc-pwrseq = <&sdio_pwrseq>;
+	non-removable;
+	pinctrl-names = "default";
+	pinctrl-0 = <&sdio0_bus4>, <&sdio0_cmd>, <&sdio0_clk>, <&sdio0_int>;
+	max-frequency = <50000000>;
+	sd-uhs-sdr12;
+	sd-uhs-sdr25;
+	sd-uhs-sdr50;
+	sd-uhs-ddr50;
+	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 */
-- 
beagleboard@davidjohnsummers.uk