1ca6828db9
Replace device_get_binding with DEVICE_DT_GET for getting access to the pwm controller device. Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
81 lines
1.7 KiB
C
81 lines
1.7 KiB
C
/*
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* Copyright (c) 2016 Intel Corporation
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* Copyright (c) 2020 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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/**
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* @file Sample app to demonstrate PWM-based LED fade
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*/
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#include <zephyr.h>
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#include <sys/printk.h>
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#include <device.h>
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#include <drivers/pwm.h>
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#define PWM_LED0_NODE DT_ALIAS(pwm_led0)
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#if DT_NODE_HAS_STATUS(PWM_LED0_NODE, okay)
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#define PWM_CTLR DT_PWMS_CTLR(PWM_LED0_NODE)
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#define PWM_CHANNEL DT_PWMS_CHANNEL(PWM_LED0_NODE)
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#define PWM_FLAGS DT_PWMS_FLAGS(PWM_LED0_NODE)
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#else
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#error "Unsupported board: pwm-led0 devicetree alias is not defined"
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#define PWM_CTLR DT_INVALID_NODE
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#define PWM_CHANNEL 0
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#define PWM_FLAGS 0
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#endif
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/*
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* This period should be fast enough to be above the flicker fusion
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* threshold. The steps should also be small enough, and happen
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* quickly enough, to make the output fade change appear continuous.
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*/
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#define PERIOD_USEC 20000U
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#define NUM_STEPS 50U
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#define STEP_USEC (PERIOD_USEC / NUM_STEPS)
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#define SLEEP_MSEC 25U
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void main(void)
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{
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const struct device *pwm;
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uint32_t pulse_width = 0U;
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uint8_t dir = 1U;
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int ret;
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printk("PWM-based LED fade\n");
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pwm = DEVICE_DT_GET(PWM_CTLR);
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if (!device_is_ready(pwm)) {
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printk("Error: PWM device %s is not ready\n", pwm->name);
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return;
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}
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while (1) {
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ret = pwm_pin_set_usec(pwm, PWM_CHANNEL, PERIOD_USEC,
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pulse_width, PWM_FLAGS);
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if (ret) {
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printk("Error %d: failed to set pulse width\n", ret);
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return;
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}
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if (dir) {
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pulse_width += STEP_USEC;
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if (pulse_width >= PERIOD_USEC) {
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pulse_width = PERIOD_USEC - STEP_USEC;
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dir = 0U;
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}
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} else {
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if (pulse_width >= STEP_USEC) {
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pulse_width -= STEP_USEC;
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} else {
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pulse_width = STEP_USEC;
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dir = 1U;
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}
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}
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k_sleep(K_MSEC(SLEEP_MSEC));
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}
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}
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