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