Subversion Repositories idreammicro-avr

/**************************************************************************//**
 * \brief SPI library
 * \author Copyright (C) 2011  Julien Le Sech - www.idreammicro.com
 * \version 1.0
 * \date 20110315
 *
 * This file is part of the iDreamMicro library.
 *
 * This library is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 *
 * This library 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 Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see http://www.gnu.org/licenses/
 ******************************************************************************/

/**************************************************************************//**
 * \file spi_slave.c
 ******************************************************************************/

/******************************************************************************
 * Header file inclusions.
 ******************************************************************************/

#include <spi/spi.h>

#include <useful/bits.h>

#include <avr/io.h>

#include <stdint.h>

#if defined (__AVR_ATmega128__)
    #include "../include/spi_atmega128.h"
#elif defined (__AVR_ATmega328P__) || defined (__AVR_ATmega328__)
    #include "../include/spi_atmega328.h"
#elif defined (__AVR_ATmega2560__)
    #include "../include/spi_atmega2560.h"
#endif

/******************************************************************************
 * Public function definitions.
 ******************************************************************************/

/**************************************************************************//**
 * \fn void spi_slave__initialize(void)
 *
 * \brief Initialize SPI in slave mode.
 ******************************************************************************/
void
spi_slave__initialize
(
    void
){
    // Configure pins.
    DDR_SPI = _BV(DD_MISO);

    // Enable SPI.
    SPCR = _BV(SPE);
}

/**************************************************************************//**
 * \fn uint8_t spi_slave__receive(void)
 *
 * \brief Receive data.
 *
 * \return Received data.
 ******************************************************************************/
uint8_t
spi_slave__receive
(
    void
){
    // Wait for previous transmission complete.
    while (!(SPSR & (1 << SPIF)));

    // Read data from SPI data register.
    return SPDR;
}