device_get_binding returning NULL for a custom board (blinky example)

[Eduan Shuda]

I created a simple custom board (in VS Code 'Create a new board' Wizard) based on nrf9160 secure.

I copied the LED part of the original dts and I want to run blinky.

At first it worked, then somehow somewhere it stopped working. I traced the issue down to the function device_get_binding() that keeps returning NULL for my custom board even though all applicable settings and pins are identical.

I have tried the same with nrf52840 and nrf52832 and I get the same result.

The frustrating part is that it did work and stopped working all of a sudden - Is there some global setting that I could have accidently changed?

[Depraz]

Hello Eduan, can you share the device tree you are using and show the definition of LED0 ?

[Eduan Shuda]

Hi, this is the dts file for the nrf52832 example:

// Copyright (c) 2022 Nordic Semiconductor ASA
// SPDX-License-Identifier: Apache-2.0

/dts-v1/;
#include <nordic/nrf52832_ciaa.dtsi>

/ {
	model = "act";
	compatible = "nordic,act";

	chosen {
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
	};

	leds {
		compatible = "gpio-leds";
		led0: led_0 {
			/* ANNA-B1 GPIO_29 */
			gpios = <&gpio0 27 GPIO_ACTIVE_LOW>;
			label = "Red LED";
		};
		led1: led_1 {
			/* ANNA-B1 GPIO_30 */
			gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;
			label = "Green LED";
		};
		led2: led_2 {
			/*ANNA-B1 GPIO_31 */
			gpios = <&gpio0 26 GPIO_ACTIVE_LOW>;
			label = "Blue LED";
		};
	};

	aliases {
		led0 = &led0;
		led1 = &led1;
		led2 = &led2;
	};
};

&flash0 {
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x0 0xc000>;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0xc000 0x32000>;
		};
		slot1_partition: partition@3e000 {
			label = "image-1";
			reg = <0x3e000 0x32000>;
		};
		scratch_partition: partition@70000 {
			label = "image-scratch";
			reg = <0x70000 0xa000>;
		};
		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x7a000 0x6000>;
		};
	};
};

[Eduan Shuda]

Here is my main.c:

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>

/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS   1000

/* The devicetree node identifier for the "led0" alias. */
#define LED0_NODE DT_ALIAS(led0)

#if DT_NODE_HAS_STATUS(LED0_NODE, okay)
#define LED0	DT_GPIO_LABEL(LED0_NODE, gpios)
#define PIN	DT_GPIO_PIN(LED0_NODE, gpios)
#define FLAGS	DT_GPIO_FLAGS(LED0_NODE, gpios)
#else
/* A build error here means your board isn't set up to blink an LED. */
#error "Unsupported board: led0 devicetree alias is not defined"
#define LED0	""
#define PIN	0
#define FLAGS	0
#endif

void main(void)
{
	const struct device *dev;
	bool led_is_on = true;
	int ret;

	dev = device_get_binding(LED0);
	if (dev == NULL) {
		return;
	}

	ret = gpio_pin_configure(dev, PIN, GPIO_OUTPUT_ACTIVE | FLAGS);
	if (ret < 0) {
		return;
	}

	while (1) {
		gpio_pin_set(dev, PIN, (int)led_is_on);
		led_is_on = !led_is_on;
		k_msleep(SLEEP_TIME_MS);
	}
}

[Depraz]

Can you try with:

#define C_LED_LABEL DT_GPIO_LABEL(LED0_NODE, gpios)
device_get_binding(C_LED_LABEL);

[Eduan Shuda]

Nope, same issue. How can something as simple as this not work? This is really frustrating