matrix_keypad.h

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/*
 * Copyright (C) 2021 Koen Zandberg
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */
 
#pragma once

 
#include <stdint.h>
#include <stdbool.h>
#include "periph/gpio.h"
 
#ifdef __cplusplus
extern "C" {
#endif

#ifndef CONFIG_MATRIX_KEYPAD_NUM_ROWS
#define CONFIG_MATRIX_KEYPAD_NUM_ROWS   2
#endif

#ifndef CONFIG_MATRIX_KEYPAD_NUM_COLUMNS
#define CONFIG_MATRIX_KEYPAD_NUM_COLUMNS   2
#endif

#ifndef CONFIG_MATRIX_KEYPAD_DEBOUNCE_PATTERN_BEGIN
#define CONFIG_MATRIX_KEYPAD_DEBOUNCE_PATTERN_BEGIN  0xC0
#endif

#ifndef CONFIG_MATRIX_KEYPAD_DEBOUNCE_PATTERN_END
#define CONFIG_MATRIX_KEYPAD_DEBOUNCE_PATTERN_END  0x7
#endif

#ifndef CONFIG_MATRIX_KEYPAD_ROWS_USE_OPEN_DRAIN
#define CONFIG_MATRIX_KEYPAD_ROWS_USE_OPEN_DRAIN  0
#endif

#if CONFIG_MATRIX_KEYPAD_ROWS_USE_OPEN_DRAIN
#define MATRIX_KEYPAD_ROWS_GPIO_MODE GPIO_OD_PU
#else
#define MATRIX_KEYPAD_ROWS_GPIO_MODE GPIO_OUT
#endif

#define MATRIX_KEYPAD_DEBOUNCE_MASK  \
    (CONFIG_MATRIX_KEYPAD_DEBOUNCE_PATTERN_BEGIN | CONFIG_MATRIX_KEYPAD_DEBOUNCE_PATTERN_END)

#if CONFIG_MATRIX_KEYPAD_NUM_COLUMNS <= 8
typedef uint8_t matrix_keypad_state_row_t;
#elif CONFIG_MATRIX_KEYPAD_NUM_COLUMNS <= 16
typedef uint16_t matrix_keypad_state_row_t;
#elif CONFIG_MATRIX_KEYPAD_NUM_COLUMNS <= 32
typedef uint32_t matrix_keypad_state_row_t;
#elif CONFIG_MATRIX_KEYPAD_NUM_COLUMNS <= 64
typedef uint64_t matrix_keypad_state_row_t;
#else
#error Too many columns on matrix keypad.
#endif

typedef struct {
    gpio_t rows[CONFIG_MATRIX_KEYPAD_NUM_ROWS];
    gpio_t columns[CONFIG_MATRIX_KEYPAD_NUM_COLUMNS];
    uint32_t row2col_delay;
} matrix_keypad_params_t;

typedef void (*matrix_keypad_cb_t)(void *arg, size_t row, size_t column, bool state);

typedef struct {
    const matrix_keypad_params_t *params;

    uint8_t debounce[CONFIG_MATRIX_KEYPAD_NUM_ROWS][CONFIG_MATRIX_KEYPAD_NUM_COLUMNS];

    matrix_keypad_state_row_t state[CONFIG_MATRIX_KEYPAD_NUM_ROWS];

    void *arg;

    matrix_keypad_cb_t callback;
} matrix_keypad_t;

int matrix_keypad_init(matrix_keypad_t *dev,
                       const matrix_keypad_params_t *params,
                       matrix_keypad_cb_t callback,
                       void *arg);

size_t matrix_keypad_scan(matrix_keypad_t *dev);
#ifdef __cplusplus
}
#endif