samples/drivers/led/pwm/src/main.c

/*
 * Copyright (c) 2020 Seagate Technology LLC
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <errno.h>
#include <zephyr/drivers/led.h>
#include <zephyr/sys/util.h>
#include <zephyr/kernel.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(main, CONFIG_LOG_DEFAULT_LEVEL);

#define LED_PWM_NODE_ID	 DT_COMPAT_GET_ANY_STATUS_OKAY(pwm_leds)

const char *led_label[] = {
	DT_FOREACH_CHILD_SEP_VARGS(LED_PWM_NODE_ID, DT_PROP_OR, (,), label, NULL)
};

const int num_leds = ARRAY_SIZE(led_label);

#define MAX_BRIGHTNESS	100

/**
 * @brief Run tests on a single LED using the LED API syscalls.
 *
 * @param led_pwm LED PWM device.
 * @param led Number of the LED to test.
 */
static void run_led_test(const struct device *led_pwm, uint8_t led)
{
	int err;
	int16_t level;

	LOG_INF("Testing LED %d - %s", led, led_label[led] ? : "no label");

	/* Turn LED on. */
	err = led_on(led_pwm, led);
	if (err < 0) {
		LOG_ERR("err=%d", err);
		return;
	}
	LOG_INF("  Turned on");
	k_sleep(K_MSEC(1000));

	/* Turn LED off. */
	err = led_off(led_pwm, led);
	if (err < 0) {
		LOG_ERR("err=%d", err);
		return;
	}
	LOG_INF("  Turned off");
	k_sleep(K_MSEC(1000));

	/* Increase LED brightness gradually up to the maximum level. */
	LOG_INF("  Increasing brightness gradually");
	for (level = 0; level <= MAX_BRIGHTNESS; level++) {
		err = led_set_brightness(led_pwm, led, level);
		if (err < 0) {
			LOG_ERR("err=%d brightness=%d\n", err, level);
			return;
		}
		k_sleep(K_MSEC(CONFIG_FADE_DELAY));
	}
	k_sleep(K_MSEC(1000));

	/* Decrease LED brightness gradually down to the minimum level. */
	LOG_INF("  Decreasing brightness gradually");
	for (level = MAX_BRIGHTNESS; level >= 0; level--) {
		err = led_set_brightness(led_pwm, led, level);
		if (err < 0) {
			LOG_ERR("err=%d brightness=%d\n", err, level);
			return;
		}
		k_sleep(K_MSEC(CONFIG_FADE_DELAY));
	}
	k_sleep(K_MSEC(1000));

#if CONFIG_BLINK_DELAY_SHORT > 0
	/* Start LED blinking (short cycle) */
	err = led_blink(led_pwm, led, CONFIG_BLINK_DELAY_SHORT, CONFIG_BLINK_DELAY_SHORT);
	if (err < 0) {
		LOG_ERR("err=%d", err);
		return;
	}
	LOG_INF("  Blinking "
		"on: " STRINGIFY(CONFIG_BLINK_DELAY_SHORT) " msec, "
		"off: " STRINGIFY(CONFIG_BLINK_DELAY_SHORT) " msec");
	k_sleep(K_MSEC(5000));
#endif

#if CONFIG_BLINK_DELAY_LONG > 0
	/* Start LED blinking (long cycle) */
	err = led_blink(led_pwm, led, CONFIG_BLINK_DELAY_LONG, CONFIG_BLINK_DELAY_LONG);
	if (err < 0) {
		LOG_ERR("err=%d", err);
		LOG_INF("  Cycle period not supported - "
			"on: " STRINGIFY(CONFIG_BLINK_DELAY_LONG) "  msec, "
			"off: " STRINGIFY(CONFIG_BLINK_DELAY_LONG) " msec");
	} else {
		LOG_INF("  Blinking "
			"on: " STRINGIFY(CONFIG_BLINK_DELAY_LONG) " msec, "
			"off: " STRINGIFY(CONFIG_BLINK_DELAY_LONG) " msec");
	}
	k_sleep(K_MSEC(5000));
#endif

	/* Turn LED off. */
	err = led_off(led_pwm, led);
	if (err < 0) {
		LOG_ERR("err=%d", err);
		return;
	}
	LOG_INF("  Turned off, loop end");
}

int main(void)
{
	const struct device *led_pwm;
	uint8_t led;

	led_pwm = DEVICE_DT_GET(LED_PWM_NODE_ID);
	if (!device_is_ready(led_pwm)) {
		LOG_ERR("Device %s is not ready", led_pwm->name);
		return 0;
	}

	if (!num_leds) {
		LOG_ERR("No LEDs found for %s", led_pwm->name);
		return 0;
	}

	do {
		for (led = 0; led < num_leds; led++) {
			run_led_test(led_pwm, led);
		}
	} while (true);
	return 0;
}