qmk-firmware/keyboards/sx60/sx60.h

#pragma once

#include "quantum.h"
#include <stdint.h>
#include <stdbool.h>
#include "i2c_master.h"
#include <util/delay.h>

/* I2C aliases and register addresses (see "mcp23018.md") */
#define I2C_ADDR        (0b0100000 << 1)
#define I2C_TIMEOUT     100
#define IODIRA          0x00            /* i/o direction register */
#define IODIRB          0x01
#define GPPUA           0x0C            /* GPIO pull-up resistor register */
#define GPPUB           0x0D
#define GPIOA           0x12            /* general purpose i/o port register (write modifies OLAT) */
#define GPIOB           0x13
#define OLATA           0x14            /* output latch register */
#define OLATB           0x15

extern uint8_t mcp23018_status;

uint8_t init_mcp23018(void);