/***************************************************************************
 *   Copyright (C) 2024 - 2025 by Federico Amedeo Izzo IU2NUO,             *
 *                                Niccolò Izzo IU2KIN                      *
 *                                Frederik Saraci IU2NRO                   *
 *                                Silvano Seva IU2KWO                      *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 3 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, see <http://www.gnu.org/licenses/>   *
 ***************************************************************************/

#include <errno.h>
#include "spi_custom.h"

int spiCustom_transfer(const struct spiDevice *dev, const void *txBuf,
                       void *rxBuf, const size_t size)
{
    const struct spiCustomDevice *spiDev = (const struct spiCustomDevice *) dev;
    const uint8_t *txData = (const uint8_t *) txBuf;
    uint8_t       *rxData = (uint8_t *) rxBuf;

    if(spiDev->spiFunc == NULL)
        return -EIO;

    // Send only
    if(rxBuf == NULL)
    {
        for(size_t i = 0; i < size; i++)
            spiDev->spiFunc(dev->priv, txData[i]);

        return 0;
    }

    // Receive only
    if(txBuf == NULL)
    {
        for(size_t i = 0; i < size; i++)
            rxData[i] = spiDev->spiFunc(dev->priv, 0x00);

        return 0;
    }

    // Transmit and receive, only symmetric transfer is supported
    for(size_t i = 0; i < size; i++)
        rxData[i] = spiDev->spiFunc(dev->priv, txData[i]);

    return 0;
}