io_pin_remap.cpp

#if defined(BOARD_HAS_PIN_REMAP) && !defined(ARDUINO_CORE_BUILD)
// -DARDUINO_CORE_BUILD must be set for core files only, to avoid extra
// remapping steps that would create all sorts of issues in the core.
// Removing -DBOARD_HAS_PIN_REMAP at least does correctly restore the
// use of GPIO numbers in the API.
#error This build system is not supported. Please rebuild without BOARD_HAS_PIN_REMAP.
#endif

#if !defined(BOARD_HAS_PIN_REMAP)
// This board uses pin mapping but the build system has disabled it
#warning The build system forces the Arduino API to use GPIO numbers on a board that has custom pin mapping.
#elif defined(BOARD_USES_HW_GPIO_NUMBERS)
// The user has chosen to disable pin mappin.
#warning The Arduino API will use GPIO numbers for this build.
#endif

#include "Arduino.h"

// NOTE: This must match with the remapped pin sequence in pins_arduino.h
static const int8_t TO_GPIO_NUMBER[] = {
    44, // [ 0] D0, RX
    43, // [ 1] D1, TX
    5,  // [ 2] D2
    6,  // [ 3] D3, CTS
    7,  // [ 4] D4, DSR
    8,  // [ 5] D5
    9,  // [ 6] D6
    10, // [ 7] D7
    17, // [ 8] D8
    18, // [ 9] D9
    21, // [10] D10, SS
    38, // [11] D11, MOSI
    47, // [12] D12, MISO
    48, // [13] D13, SCK, LED_BUILTIN
    46, // [14] LED_RED
    0,  // [15] LED_GREEN
    45, // [16] LED_BLUE, RTS
    1,  // [17] A0, DTR
    2,  // [18] A1
    3,  // [19] A2
    4,  // [20] A3
    11, // [21] A4, SDA
    12, // [22] A5, SCL
    13, // [23] A6
    14, // [24] A7
};

void _nano_nora_reset_gpio_matrix(void)
{
    // In this core file pin mapping is _not_ applied, so the API is
    // always GPIO-based, but the constants can be either.
    for (int pin = 0; pin < sizeof(TO_GPIO_NUMBER); ++pin) {
        int gpio = TO_GPIO_NUMBER[pin];
#if defined(BOARD_HAS_PIN_REMAP) && !defined(BOARD_USES_HW_GPIO_NUMBERS)
        // Pin remapping in effect, constants = indexes
        switch (pin) {
#else
        // Pin remapping disabled, constants = GPIO numbers
        switch (gpio) {
#endif
            case LED_RED:
            case LED_GREEN:
            case LED_BLUE:
                // set RGB pins to dig outputs, HIGH=off
                pinMode(gpio, OUTPUT);
                digitalWrite(gpio, HIGH);
                break;

            case TX:
            case RX:
                // leave UART pins alone
                break;

            default:
                // initialize other pins to dig inputs
                pinMode(gpio, INPUT);
                break;
        }
    }
}

#if defined(BOARD_HAS_PIN_REMAP) && !defined(BOARD_USES_HW_GPIO_NUMBERS)

int8_t digitalPinToGPIONumber(int8_t digitalPin)
{
    if ((digitalPin < 0) || (digitalPin >= NUM_DIGITAL_PINS))
        return -1;
    return TO_GPIO_NUMBER[digitalPin];
}

int8_t gpioNumberToDigitalPin(int8_t gpioNumber)
{
    if (gpioNumber < 0)
        return -1;

    // slow linear table lookup
    for (int8_t digitalPin = 0; digitalPin < NUM_DIGITAL_PINS; ++digitalPin) {
        if (TO_GPIO_NUMBER[digitalPin] == gpioNumber)
            return digitalPin;
    }

    // not found
    return -1;
}

#endif