Arduino yun openwrt 19 ATH79 port devicetree

ar9331_arduino-yun.dts

// SPDX-License-Identifier: GPL-2.0
/dts-v1/;

#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/input/input.h>

#include "ar9331.dtsi"
/*

ar9331 GPIO : function
26	: bitbang SPI SS ( uses spi-gpio-custom )
27	: bitbang SPI MOSI
8	: bitbang SPI MISO
11	: bitbang SPI SCK
21	: SPI level shifter enable
19	: AVR handsake signal ( has 10k pullup )
6	: GP6 on pcb
22	: handshake and GP6 level shifter enable
23	: UART level shifter enable
18 	: AVR reset
20	: configuration button
1	: LED0 : Wireless LED (blue)
0	: LED1 : USB/System Led (White)
17	: LED6 : WAN led (yellow)
*/
/ {
	model = "Arduino Yun";
	compatible = "Yun", "qca,ar9331";

	aliases {
		serial0 = &uart;
		led-boot = &led_system;
		led-failsafe = &led_system;
		led-running = &led_system;
		led-upgrade = &led_system;
	};

	leds {
		compatible = "gpio-leds";
		pinctrl-names = "default";
		pinctrl-0 = <&switch_led_disable_pins>;

		led_system: system {
			label = "arduino:white:usb";
			gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
			default-state = "on";
		};

 		wlan {
                         label = "arduino:blue:wlan";
                         gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
                         default-state = "off";
			 linux,default-trigger = "phy0tpt";
                };
 
            	lan {
                         label = "arduino:yellow:wan";
                         gpios = <&gpio 17 GPIO_ACTIVE_LOW>; 
                         default-state = "off";
                };
	
	};
	keys {
		compatible = "gpio-keys-polled";
		poll-interval = <20>;

		button0 {
			label = "configuration button";
			linux,code = <KEY_WPS_BUTTON>;
			gpios = <&gpio 20 GPIO_ACTIVE_LOW>;
		};
 
	};

	gpio-export {
 		compatible = "gpio-export";
		pinctrl-names = "default";
		pinctrl-0 = <&mdio_gpio &jtag_disable_pins &jumpstart_disable>; // needed for GPIO 26 and 27 

		gpio_DS2_OE_1 { // Put the avr reset to high ( was used on older boards, new ones use 18 )
			gpio-export,name = "DS2_OE-1";
			gpio-export,output = <0>; // init low
			gpio-export,direction_may_change;
			gpios = <&gpio 7 GPIO_ACTIVE_HIGH>;
		};

		gpio_level_shifter { // enable OE of level shifter ( SPI )
			gpio-export,name = "OE-1";
			gpio-export,output = <0>; // init low = disabled
			gpio-export,direction_may_change;
			gpios = <&gpio 21 GPIO_ACTIVE_HIGH>;
		};

		gpio_OE2 { 	// enable OE of level shifter ( handshake )
			gpio-export,name = "OE-2";
			gpio-export,output = <0>; // init low = disabled
			gpio-export,direction_may_change;
			gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
		};

		gpio_uart_en { // enable level shifter ( UART )
			gpio-export,name = "UART-ENA";
			gpio-export,output = <0>; // init low = enabled
			gpio-export,direction_may_change;
			gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
		};
		
		gpio_avr_reset { // AVR reset 
			gpio-export,name = "AVR-RESET";
			gpio-export,output = <0>; // init low ( AVR running normally - take High to Reset)
			gpio-export,direction_may_change;
			gpios = <&gpio 18 GPIO_ACTIVE_HIGH>;
		};

		gpio_handshake { // AVR handshake signal 
			gpio-export,name = "AVR-Handshake";
			gpio-export,output = <0>; // init low ( AVR running normally - take High to Reset)
			gpio-export,direction_may_change;
			gpios = <&gpio 19 GPIO_ACTIVE_HIGH>;
		};

		gpio_gpio6 { // AVR reset (take High to Reset)
			gpio-export,name = "GPIO6";
			gpio-export,output = <1>; // init high (has external 10k pullup )
			gpio-export,direction_may_change;
			gpios = <&gpio 6 GPIO_ACTIVE_HIGH>;
		};


	};

};
// arduino uses 250000 baud, possibly for "bridge" library to exchange data between AVR and Linux, needs a baudrate patch
&chosen {
		bootargs = "console=ttyATH0,115200";
	};

&ref {
	clock-frequency = <25000000>;
};

&uart {
	status = "okay";
};

&gpio {
	status = "okay";
};

&usb {
	dr_mode = "host";
	status = "okay";
};

&usb_phy {
	status = "okay";
};

&spi {
	num-chipselects = <1>;
	status = "okay";

	/* Winbond 25Q128FVSG SPI flash */
	flash@0 {
		compatible = "jedec,spi-nor";
		spi-max-frequency = <104000000>;
		reg = <0>;
		partitions {
                          compatible = "fixed-partitions";
                          #address-cells = <1>;
                          #size-cells = <1>;
  
                          partition@0 {
                                  label = "u-boot";
                                  reg = <0x000000 0x040000>;
                                  read-only;
                          };
  
                          partition@1 {
                                  label = "u-boot-env";
                                  reg = <0x040000 0x010000>;
                          };
  
                          partition@2 {
				  compatible = "denx,uimage";
                                  label = "firmware";
                                  reg = <0x050000 0xfa0000>;
                          };
  
                          art: partition@3 {
                                  label = "art";
                                  reg = <0xff0000 0x010000>;
                                  read-only;
                          };
                  };
	};
};


&eth0 {
	// ETH0 ( wired ) gets MAC adress from art partition, modified : mac[3] |= 0x08; 
	// we cannot |=08  in dt, so we just increment by 1 so its different from wlan
	status = "okay";
	mtd-mac-address = <&art 0x0000>;
	//mtd-mac-address-increment-byte = <3>;
	//mtd-mac-address-increment = <(-1)>;
};

&eth1 {
	// ETH1 ( wired into switch but not present on PCB ) gets MAC adress from art partition, modified mac[3] &= 0xF7;
	status = "okay";
	mtd-mac-address = <&art 0x0006>;
	//mtd-mac-address-increment-byte = <3>;
	//mtd-mac-address-increment = <1>;
};

&wmac {
	// wmac ( wireless ) gets MAC adress from ART partition unmolested
	status = "okay";
	mtd-cal-data = <&art 0x1000>;
	mtd-mac-address = <&art 0x1002>;
};

&switch_led_disable_pins{
	// disable switch controlled LEDs to use them as regular GPIO (13,14,15,16) ,  <offset value mask>;
	pinctrl-single,bits = <0x0 0x0 0xf8>;
};