SPISettings.h

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/****
 * Sming Framework Project - Open Source framework for high efficiency native ESP8266 development.
 * Created 2015 by Skurydin Alexey
 * http://github.com/SmingHub/Sming
 * All files of the Sming Core are provided under the LGPL v3 license.
 *
 * SPISettings.h
 *
 *  Created on: Mar 2, 2016
 *      Author: harry
 *
 ****/

#pragma once

#include <Digital.h>
#include <sming_attr.h>
#ifdef SPI_DEBUG
#include <debug_progmem.h>
#endif

// Mode         Clock Polarity (CPOL)   Clock Phase (CPHA)
//  SPI_MODE0       0                   0
//  SPI_MODE1       0                   1
//  SPI_MODE2       1                   0
//  SPI_MODE3       1                   1

enum SpiMode : uint8_t {
    SPI_MODE0 = 0x00,
    SPI_MODE1 = 0x0F,
    SPI_MODE2 = 0xF0,
    SPI_MODE3 = 0xFF,
};

const uint32_t SPI_SPEED_DEFAULT = 4000000UL;

struct SPISpeed {
    uint32_t frequency{0};
    uint32_t regVal{0}; 

    SPISpeed(uint32_t freq = SPI_SPEED_DEFAULT) : frequency(freq)
    {
    }

    SPISpeed& operator=(uint32_t freq)
    {
        setFrequency(freq);
        return *this;
    }

    bool operator==(const SPISpeed& speed) const
    {
        return frequency == speed.frequency;
    }

    void setFrequency(uint32_t freq)
    {
        if(freq != frequency) {
            frequency = freq;
            regVal = 0;
        }
    }
};

class SPISettings
{
public:
    SPISettings()
    {
#ifdef SPI_DEBUG
        debugf("SPISettings::SPISettings() default");
#endif
    }

    SPISettings(uint32_t speed, uint8_t bitOrder, SpiMode dataMode)
        : speed(speed), bitOrder(bitOrder), dataMode(dataMode)
    {
#ifdef SPI_DEBUG
        debugf("SPISettings(int %i, uint8 %u, uint8 %u)", speed, bitOrder, dataMode);
#endif
    }

    /*
     * Arduino libraries use non-typed dataMode
     */
    SPISettings(uint32_t speed, uint8_t bitOrder, uint8_t dataMode)
        : speed(speed), bitOrder(bitOrder), dataMode(SpiMode(dataMode))
    {
    }

    // overload operator to check whether the settings are equal
    bool operator==(const SPISettings& other) const
    {
        return (speed == other.speed) && (bitOrder == other.bitOrder) && (dataMode == other.dataMode);
    }

    void print(const char* s)
    {
#ifdef SPI_DEBUG
        debugf("->  %s -> SPISettings(%u, %u, %u)", s, speed.frequency, bitOrder, dataMode);
#endif
    }

    static uint8_t getModeNum(SpiMode mode)
    {
        return (mode <= 3) ? mode : ((mode & 0x10) >> 3) | (mode & 0x01);
    }

    SPISpeed speed;
    uint8_t bitOrder{MSBFIRST};
    SpiMode dataMode{SPI_MODE0};
};