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/*
* Copyright (c) 2021 The ZMK Contributors
*
* SPDX-License-Identifier: MIT
*/
#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <sys/util.h>
#define DEBOUNCE_COUNTER_BITS 14
#define DEBOUNCE_COUNTER_MAX BIT_MASK(DEBOUNCE_COUNTER_BITS)
struct debounce_state {
bool pressed : 1;
bool changed : 1;
uint16_t counter : DEBOUNCE_COUNTER_BITS;
};
struct debounce_config {
/** Duration a switch must be pressed to latch as pressed. */
uint32_t debounce_press_ms;
/** Duration a switch must be released to latch as released. */
uint32_t debounce_release_ms;
};
/**
* Debounces one switch.
*
* @param state The state for the switch to debounce.
* @param active Is the switch currently pressed?
* @param elapsed_ms Time elapsed since the previous update in milliseconds.
* @param config Debounce settings.
*/
void debounce_update(struct debounce_state *state, const bool active, const int elapsed_ms,
const struct debounce_config *config);
/**
* @returns whether the switch is either latched as pressed or it is potentially
* pressed but the debouncer has not yet made a decision. If this returns true,
* the kscan driver should continue to poll quickly.
*/
bool debounce_is_active(const struct debounce_state *state);
/**
* @returns whether the switch is latched as pressed.
*/
bool debounce_is_pressed(const struct debounce_state *state);
/**
* @returns whether the pressed state of the switch changed in the last call to
* debounce_update.
*/
bool debounce_get_changed(const struct debounce_state *state);