SPI.h

/*
 * Copyright (c) 2010 by Cristian Maglie <c.maglie@arduino.cc>
 * Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API)
 * 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.
 */

#ifndef _SPI_H_INCLUDED
#define _SPI_H_INCLUDED

#include "variant.h"
#include <stdio.h>
#include <inttypes.h>

// SPI_HAS_TRANSACTION means SPI has
//   - beginTransaction()
//   - endTransaction()
//   - usingInterrupt()
//   - SPISetting(clock, bitOrder, dataMode)
#define SPI_HAS_TRANSACTION 1

// SPI_HAS_EXTENDED_CS_PIN_HANDLING means SPI has automatic 
// CS pin handling and provides the following methods:
//   - begin(pin)
//   - end(pin)
//   - setBitOrder(pin, bitorder)
//   - setDataMode(pin, datamode)
//   - setClockDivider(pin, clockdiv)
//   - transfer(pin, data, SPI_LAST/SPI_CONTINUE)
//   - beginTransaction(pin, SPISettings settings) (if transactions are available)
#define SPI_HAS_EXTENDED_CS_PIN_HANDLING 1

#define SPI_MODE0 0x00
#define SPI_MODE1 0x01
#define SPI_MODE2 0x02
#define SPI_MODE3 0x03

enum SPITransferMode {
    SPI_CONTINUE,
    SPI_LAST
};

class SPISettings {
public:
    SPISettings(uint32_t clock, BitOrder bitOrder, uint8_t dataMode) {
        _clock = clock;
        _bitOrder = bitOrder;
        _dataMode = dataMode;
    }
    SPISettings() {
        SPISettings(4000000, MSBFIRST, SPI_MODE0);
    }

private:
    uint32_t _clock;
    BitOrder _bitOrder;
    uint8_t _dataMode;

    friend class SPIClass;
};

class SPIClass {
public:
    SPIClass(void *pSpiObj, int mosi, int miso, int clk, int ss);

    byte transfer(byte _pin, uint8_t _data, SPITransferMode _mode = SPI_LAST);
    byte transfer(uint8_t _data, SPITransferMode _mode = SPI_LAST);

    void transfer(byte _pin, void *_buf, size_t _count, SPITransferMode _mode = SPI_LAST);
    void transfer(void *_buf, size_t _count, SPITransferMode _mode = SPI_LAST);

    uint16_t transfer16(byte _pin, uint16_t _data, SPITransferMode _mode = SPI_LAST);
    uint16_t transfer16(uint16_t _data, SPITransferMode _mode = SPI_LAST);

    void beginTransaction(uint8_t pin, SPISettings settings);
    void beginTransaction(SPISettings settings);
    void endTransaction(void);

    void begin(void);
    void begin(int ss);
    void end(void);

    void setBitOrder(uint8_t _pin, BitOrder _bitOrder);
    void setDataMode(uint8_t _pin, uint8_t _mode);
    void setClockDivider(uint8_t _pin, uint8_t _divider);

    void setBitOrder(BitOrder _order);
    void setDataMode(uint8_t _mode);
    void setClockDivider(uint8_t _div);

    /* extend api added by RTK */
    void setDefaultFrequency(int _frequency);

private:
    void *pSpiMaster;
    int pinMOSI;
    int pinMISO;
    int pinCLK;
    int pinSS;
    int pinUserSS;
    BitOrder bitOrder;

    int defaultFrequency; 
};

#if defined(BOARD_RTL8722DM)
extern SPIClass SPI;
extern SPIClass SPI1;
#elif defined(BOARD_RTL8722DM_MINI)
extern SPIClass SPI;
#elif defined(BOARD_RTL8720DN_BW16)
extern SPIClass SPI;
#else
#error check the board supported
#endif

#endif