57 lines
1.6 KiB
C
57 lines
1.6 KiB
C
|
/*
|
||
|
|
* 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);
|