source: rtos_arduino/trunk/arduino_lib/hardware/arduino/samd/libraries/SPI/SPI.cpp@ 136

/*
 * Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
 * SPI Master library for arduino.
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of either the GNU General Public License version 2
 * or the GNU Lesser General Public License version 2.1, both as
 * published by the Free Software Foundation.
 */

#include "SPI.h"
#include "wiring_digital.h"
#include "assert.h"
#include "variant.h"

SPIClass::SPIClass(SERCOM *p_sercom, uint8_t uc_pinMISO, uint8_t uc_pinSCK, uint8_t uc_pinMOSI)
{
        assert(p_sercom != NULL );
        _p_sercom = p_sercom;

  _uc_pinMiso = uc_pinMISO;
  _uc_pinSCK = uc_pinSCK;
  _uc_pinMosi = uc_pinMOSI;
}

void SPIClass::begin()
{
  // PIO init
  pinPeripheral(_uc_pinMiso, g_APinDescription[_uc_pinMiso].ulPinType);
  pinPeripheral(_uc_pinSCK, g_APinDescription[_uc_pinSCK].ulPinType);
  pinPeripheral(_uc_pinMosi, g_APinDescription[_uc_pinMosi].ulPinType);

        // Default speed set to 4Mhz, SPI mode set to MODE 0 and Bit order set to MSB first.
        _p_sercom->initSPI(SPI_PAD_2_SCK_3, SERCOM_RX_PAD_0, SPI_CHAR_SIZE_8_BITS, MSB_FIRST);
        _p_sercom->initSPIClock(SERCOM_SPI_MODE_0, 4000000);
        
        _p_sercom->enableSPI();
}

void SPIClass::end()
{
        _p_sercom->resetSPI();
}

void SPIClass::setBitOrder(BitOrder order)
{
        if(order == LSBFIRST)
                _p_sercom->setDataOrderSPI(LSB_FIRST);
        else
                _p_sercom->setDataOrderSPI(MSB_FIRST);
}

void SPIClass::setDataMode(uint8_t mode)
{
        switch(mode)
        {
                case SPI_MODE0:
                        _p_sercom->setClockModeSPI(SERCOM_SPI_MODE_0);
                        break;
                        
                case SPI_MODE1:
                        _p_sercom->setClockModeSPI(SERCOM_SPI_MODE_1);
                        break;
                        
                case SPI_MODE2:
                        _p_sercom->setClockModeSPI(SERCOM_SPI_MODE_2);
                        break;
                        
                case SPI_MODE3:
                        _p_sercom->setClockModeSPI(SERCOM_SPI_MODE_3);
                        break;
                
                default:
                        break;
        }
}

void SPIClass::setClockDivider(uint8_t div)
{
        _p_sercom->setBaudrateSPI(div);
}

byte SPIClass::transfer(uint8_t data)
{
        //Writing the data
        _p_sercom->writeDataSPI(data);
        
        //Read data
        return _p_sercom->readDataSPI();
}

void SPIClass::attachInterrupt() {
        // Should be enableInterrupt()
}

void SPIClass::detachInterrupt() {
        // Should be disableInterrupt()
}

SPIClass SPI(&sercom4, 18, 20, 21);