/dts-v1/;
/plugin/;

#include <dt-bindings/board/am335x-bbw-bbb-base.h>
#include <dt-bindings/pinctrl/am33xx.h>
#include <dt-bindings/gpio/gpio.h>

/ {
	// file identification
	fragment@0 {
		target-path = "/chosen";
		__overlay__ {
			overlays {
				// XXX change property name to the name of this overlay (excluding .dts file suffix)
				gpio-demo = __TIMESTAMP__;
			};
		};
	};

	// XXX caution: not compatible with cape-universal!

	// A udev rule along these lines is recommended to create symlinks in /dev/gpio/
	//
	//	SUBSYSTEM=="subsystem", KERNEL=="gpio", ACTION=="add", \
	//		RUN+="/bin/mkdir -p /dev/gpio"
	//
	//	SUBSYSTEM=="gpio", ACTION=="add", TEST=="value", ATTR{label}!="sysfs", \
	//		RUN+="/bin/ln -sT '/sys/class/gpio/%k' /dev/gpio/%s{label}"

	fragment@1 {
		target-path = "/";
		__overlay__ {
			// If you want to use multiple overlays that do gpio configuration, be
			// sure that each uses a different device tree node!
			gpio-demo {
				compatible = "gpio-of-helper";

				// It is usually not *strictly* required to perform pinmux for
				// GPIOs since this is typically their default, but it's good
				// practice to do it anyway since:
				// 1. it makes *sure* the pinmux is right
				// 2. you can configure internal pull-up/down
				// 3. it lets the kernel know the pins are in use
				pinctrl-names = "default";
				pinctrl-0 = <&gpio_demo_pins>;

				// Note that gpio numbers for each pin can be found in the
				// comments in include/bone/black.h

				// input only, active-low; connect button between pin and gnd.
				// declaring the gpio as ACTIVE_LOW means the value reads as 1
				// when the button is pressed.
				button {
					gpio = <&gpio2 2 GPIO_ACTIVE_LOW>;  // P8.07
					input;
				};

				// output only, active-low, initially high (inactive)
				reset-thing {
					gpio = <&gpio2 3 GPIO_ACTIVE_LOW>;  // P8.08
					init-high;
				};

				// note: GPIO_ACTIVE_LOW inverts the meaning of the value, but it
				// does not invert the meaning of "init-low" / "init-high" !


				// bidirectional, initially input
				input-bidi {
					gpio = <&gpio2 5 GPIO_ACTIVE_HIGH>;  // P8.09
					input;
					dir-changeable;
				};

				// bidirectional, initially output, initially low (inactive)
				output-bidi {
					gpio = <&gpio2 4 GPIO_ACTIVE_HIGH>;  // P8.10
					init-low;
					dir-changeable;
				};
			};
		};
	};

	fragment@2 {
		target = <&am33xx_pinmux>;
		__overlay__ {
			gpio_demo_pins: gpio-demo {
				pinctrl-single,pins = <
					BONE_P8_07 (PIN_INPUT_PULLUP | MUX_MODE7 )  // gpio 2.02 / button
					BONE_P8_08 (PIN_INPUT_PULLUP | MUX_MODE7 )  // gpio 2.03 / reset-thing
					BONE_P8_09 (PIN_INPUT_PULLUP | MUX_MODE7 )  // gpio 2.05 / input-bidi
					BONE_P8_10 (PIN_INPUT_PULLUP | MUX_MODE7 )  // gpio 2.04 / output-bidi
				>;
			};
		};
	};
};