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]

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

[Depraz]

Do you have the following code somewhere in the DTS?

&gpio0 {
status = "okay";
};

 

and CONFIG_GPIO ?

[Eduan Shuda]

Hi, yes seems

&gpio0 {
status = "okay";
};

fixed it.

Weird part is that it worked without this setting before. But thanks for your help. Appreciate it.