Adafruit_SPIDevice.cpp

#include "Adafruit_SPIDevice.h"

// #define DEBUG_SERIAL Serial

/*!
 *    @brief  Create an SPI device with the given CS pin and settings
 *    @param  cspin The arduino pin number to use for chip select
 *    @param  freq The SPI clock frequency to use, defaults to 1MHz
 *    @param  dataOrder The SPI data order to use for bits within each byte,
 * defaults to SPI_BITORDER_MSBFIRST
 *    @param  dataMode The SPI mode to use, defaults to SPI_MODE0
 *    @param  theSPI The SPI bus to use, defaults to &theSPI
 */
Adafruit_SPIDevice::Adafruit_SPIDevice(int8_t cspin, uint32_t freq,
                                       BusIOBitOrder dataOrder,
                                       uint8_t dataMode, SPIClass *theSPI)
{
#ifdef BUSIO_HAS_HW_SPI
    _cs = cspin;
    _sck = _mosi = _miso = -1;
    _spi = theSPI;
    _begun = false;
    _spiSetting = new SPISettings(freq, dataOrder, dataMode);
    _freq = freq;
    _dataOrder = dataOrder;
    _dataMode = dataMode;
#else
    // unused, but needed to suppress compiler warns
    (void)cspin;
    (void)freq;
    (void)dataOrder;
    (void)dataMode;
    (void)theSPI;
#endif
}

/*!
 *    @brief  Create an SPI device with the given CS pin and settings
 *    @param  cspin The arduino pin number to use for chip select
 *    @param  sckpin The arduino pin number to use for SCK
 *    @param  misopin The arduino pin number to use for MISO, set to -1 if not
 * used
 *    @param  mosipin The arduino pin number to use for MOSI, set to -1 if not
 * used
 *    @param  freq The SPI clock frequency to use, defaults to 1MHz
 *    @param  dataOrder The SPI data order to use for bits within each byte,
 * defaults to SPI_BITORDER_MSBFIRST
 *    @param  dataMode The SPI mode to use, defaults to SPI_MODE0
 */
Adafruit_SPIDevice::Adafruit_SPIDevice(int8_t cspin, int8_t sckpin,
                                       int8_t misopin, int8_t mosipin,
                                       uint32_t freq, BusIOBitOrder dataOrder,
                                       uint8_t dataMode)
{
    _cs = cspin;
    _sck = sckpin;
    _miso = misopin;
    _mosi = mosipin;

#ifdef BUSIO_USE_FAST_PINIO
    csPort = (BusIO_PortReg *)portOutputRegister(digitalPinToPort(cspin));
    csPinMask = digitalPinToBitMask(cspin);
    if (mosipin != -1)
    {
        mosiPort = (BusIO_PortReg *)portOutputRegister(digitalPinToPort(mosipin));
        mosiPinMask = digitalPinToBitMask(mosipin);
    }
    if (misopin != -1)
    {
        misoPort = (BusIO_PortReg *)portInputRegister(digitalPinToPort(misopin));
        misoPinMask = digitalPinToBitMask(misopin);
    }
    clkPort = (BusIO_PortReg *)portOutputRegister(digitalPinToPort(sckpin));
    clkPinMask = digitalPinToBitMask(sckpin);
#endif

    _freq = freq;
    _dataOrder = dataOrder;
    _dataMode = dataMode;
    _begun = false;
}

/*!
 *    @brief  Release memory allocated in constructors
 */
Adafruit_SPIDevice::~Adafruit_SPIDevice()
{
    if (_spiSetting)
        delete _spiSetting;
}

/*!
 *    @brief  Initializes SPI bus and sets CS pin high
 *    @return Always returns true because there's no way to test success of SPI
 * init
 */
bool Adafruit_SPIDevice::begin(void)
{
    if (_cs != -1)
    {
        pinMode(_cs, OUTPUT);
        digitalWrite(_cs, HIGH);
    }

    if (_spi)
    { // hardware SPI
#ifdef BUSIO_HAS_HW_SPI
        _spi->begin();
#endif
    }
    else
    {
        pinMode(_sck, OUTPUT);

        if ((_dataMode == SPI_MODE0) || (_dataMode == SPI_MODE1))
        {
            // idle low on mode 0 and 1
            digitalWrite(_sck, LOW);
        }
        else
        {
            // idle high on mode 2 or 3
            digitalWrite(_sck, HIGH);
        }
        if (_mosi != -1)
        {
            pinMode(_mosi, OUTPUT);
            digitalWrite(_mosi, HIGH);
        }
        if (_miso != -1)
        {
            pinMode(_miso, INPUT);
        }
    }

    _begun = true;
    return true;
}

void Adafruit_SPIDevice::end(void)
{
    if (_cs != -1)
    {
        pinMode(_cs, INPUT);
    }
    if (_sck != -1)
    {
        pinMode(_sck, INPUT);
    }
    if (_mosi != -1)
    {
        pinMode(_mosi, INPUT);
    }
    if (_miso != -1)
    {
        pinMode(_miso, INPUT);
    }

    if (_spi != nullptr)
    {
        _spi->end();
    }
}

/*!
 *    @brief  Transfer (send/receive) a buffer over hard/soft SPI, without
 * transaction management
 *    @param  buffer The buffer to send and receive at the same time
 *    @param  len    The number of bytes to transfer
 */
void Adafruit_SPIDevice::transfer(uint8_t *buffer, size_t len)
{
    //
    // HARDWARE SPI
    //
    if (_spi)
    {
#ifdef BUSIO_HAS_HW_SPI
#if defined(SPARK)
        _spi->transfer(buffer, buffer, len, nullptr);
#elif defined(STM32)
        for (size_t i = 0; i < len; i++)
        {
            _spi->transfer(buffer[i]);
        }
#else
        _spi->transfer(buffer, len);
#endif
        return;
#endif
    }

    //
    // SOFTWARE SPI
    //
    uint8_t startbit;
    if (_dataOrder == SPI_BITORDER_LSBFIRST)
    {
        startbit = 0x1;
    }
    else
    {
        startbit = 0x80;
    }

    bool towrite, lastmosi = !(buffer[0] & startbit);
    uint8_t bitdelay_us = (1000000 / _freq) / 2;

    for (size_t i = 0; i < len; i++)
    {
        uint8_t reply = 0;
        uint8_t send = buffer[i];

        /*
        Serial.print("\tSending software SPI byte 0x");
        Serial.print(send, HEX);
        Serial.print(" -> 0x");
        */

        // Serial.print(send, HEX);
        for (uint8_t b = startbit; b != 0;
             b = (_dataOrder == SPI_BITORDER_LSBFIRST) ? b << 1 : b >> 1)
        {

            if (bitdelay_us)
            {
                delayMicroseconds(bitdelay_us);
            }

            if (_dataMode == SPI_MODE0 || _dataMode == SPI_MODE2)
            {
                towrite = send & b;
                if ((_mosi != -1) && (lastmosi != towrite))
                {
#ifdef BUSIO_USE_FAST_PINIO
                    if (towrite)
                        *mosiPort = *mosiPort | mosiPinMask;
                    else
                        *mosiPort = *mosiPort & ~mosiPinMask;
#else
                    digitalWrite(_mosi, towrite);
#endif
                    lastmosi = towrite;
                }

#ifdef BUSIO_USE_FAST_PINIO
                *clkPort = *clkPort | clkPinMask; // Clock high
#else
                digitalWrite(_sck, HIGH);
#endif

                if (bitdelay_us)
                {
                    delayMicroseconds(bitdelay_us);
                }

                if (_miso != -1)
                {
#ifdef BUSIO_USE_FAST_PINIO
                    if (*misoPort & misoPinMask)
                    {
#else
                    if (digitalRead(_miso))
                    {
#endif
                        reply |= b;
                    }
                }

#ifdef BUSIO_USE_FAST_PINIO
                *clkPort = *clkPort & ~clkPinMask; // Clock low
#else
                digitalWrite(_sck, LOW);
#endif
            }
            else
            { // if (_dataMode == SPI_MODE1 || _dataMode == SPI_MODE3)

#ifdef BUSIO_USE_FAST_PINIO
                *clkPort = *clkPort | clkPinMask; // Clock high
#else
                digitalWrite(_sck, HIGH);
#endif

                if (bitdelay_us)
                {
                    delayMicroseconds(bitdelay_us);
                }

                if (_mosi != -1)
                {
#ifdef BUSIO_USE_FAST_PINIO
                    if (send & b)
                        *mosiPort = *mosiPort | mosiPinMask;
                    else
                        *mosiPort = *mosiPort & ~mosiPinMask;
#else
                    digitalWrite(_mosi, send & b);
#endif
                }

#ifdef BUSIO_USE_FAST_PINIO
                *clkPort = *clkPort & ~clkPinMask; // Clock low
#else
                digitalWrite(_sck, LOW);
#endif

                if (_miso != -1)
                {
#ifdef BUSIO_USE_FAST_PINIO
                    if (*misoPort & misoPinMask)
                    {
#else
                    if (digitalRead(_miso))
                    {
#endif
                        reply |= b;
                    }
                }
            }
            if (_miso != -1)
            {
                buffer[i] = reply;
            }
        }
    }
    return;
}

/*!
 *    @brief  Transfer (send/receive) one byte over hard/soft SPI, without
 * transaction management
 *    @param  send The byte to send
 *    @return The byte received while transmitting
 */
uint8_t Adafruit_SPIDevice::transfer(uint8_t send)
{
    uint8_t data = send;
    transfer(&data, 1);
    return data;
}

/*!
 *    @brief  Manually begin a transaction (calls beginTransaction if hardware
 * SPI)
 */
void Adafruit_SPIDevice::beginTransaction(void)
{
    if (_spi)
    {
#ifdef BUSIO_HAS_HW_SPI
        _spi->beginTransaction(*_spiSetting);
#endif
    }
}

/*!
 *    @brief  Manually end a transaction (calls endTransaction if hardware SPI)
 */
void Adafruit_SPIDevice::endTransaction(void)
{
    if (_spi)
    {
#ifdef BUSIO_HAS_HW_SPI
        _spi->endTransaction();
#endif
    }
}

/*!
 *    @brief  Assert/Deassert the CS pin if it is defined
 *    @param  value The state the CS is set to
 */
void Adafruit_SPIDevice::setChipSelect(int value)
{
    if (_cs != -1)
    {
        digitalWrite(_cs, value);
    }
}

/*!
 *    @brief  Write a buffer or two to the SPI device, with transaction
 * management.
 *    @brief  Manually begin a transaction (calls beginTransaction if hardware
 *            SPI) with asserting the CS pin
 */
void Adafruit_SPIDevice::beginTransactionWithAssertingCS()
{
    beginTransaction();
    setChipSelect(LOW);
}

/*!
 *    @brief  Manually end a transaction (calls endTransaction if hardware SPI)
 *            with deasserting the CS pin
 */
void Adafruit_SPIDevice::endTransactionWithDeassertingCS()
{
    setChipSelect(HIGH);
    endTransaction();
}

/*!
 *    @brief  Write a buffer or two to the SPI device, with transaction
 * management.
 *    @param  buffer Pointer to buffer of data to write
 *    @param  len Number of bytes from buffer to write
 *    @param  prefix_buffer Pointer to optional array of data to write before
 * buffer.
 *    @param  prefix_len Number of bytes from prefix buffer to write
 *    @return Always returns true because there's no way to test success of SPI
 * writes
 */
bool Adafruit_SPIDevice::write(const uint8_t *buffer, size_t len,
                               const uint8_t *prefix_buffer,
                               size_t prefix_len)
{
    beginTransactionWithAssertingCS();

    // do the writing
#if defined(ARDUINO_ARCH_ESP32)
    if (_spi)
    {
        if (prefix_len > 0)
        {
            _spi->transferBytes((uint8_t *)prefix_buffer, nullptr, prefix_len);
        }
        if (len > 0)
        {
            _spi->transferBytes((uint8_t *)buffer, nullptr, len);
        }
    }
    else
#endif
    {
        for (size_t i = 0; i < prefix_len; i++)
        {
            transfer(prefix_buffer[i]);
        }
        for (size_t i = 0; i < len; i++)
        {
            transfer(buffer[i]);
        }
    }
    endTransactionWithDeassertingCS();

#ifdef DEBUG_SERIAL
    DEBUG_SERIAL.print(F("\tSPIDevice Wrote: "));
    if ((prefix_len != 0) && (prefix_buffer != nullptr))
    {
        for (uint16_t i = 0; i < prefix_len; i++)
        {
            DEBUG_SERIAL.print(F("0x"));
            DEBUG_SERIAL.print(prefix_buffer[i], HEX);
            DEBUG_SERIAL.print(F(", "));
        }
    }
    for (uint16_t i = 0; i < len; i++)
    {
        DEBUG_SERIAL.print(F("0x"));
        DEBUG_SERIAL.print(buffer[i], HEX);
        DEBUG_SERIAL.print(F(", "));
        if (i % 32 == 31)
        {
            DEBUG_SERIAL.println();
        }
    }
    DEBUG_SERIAL.println();
#endif

    return true;
}

/*!
 *    @brief  Read from SPI into a buffer from the SPI device, with transaction
 * management.
 *    @param  buffer Pointer to buffer of data to read into
 *    @param  len Number of bytes from buffer to read.
 *    @param  sendvalue The 8-bits of data to write when doing the data read,
 * defaults to 0xFF
 *    @return Always returns true because there's no way to test success of SPI
 * writes
 */
bool Adafruit_SPIDevice::read(uint8_t *buffer, size_t len, uint8_t sendvalue)
{
    memset(buffer, sendvalue, len); // clear out existing buffer

    beginTransactionWithAssertingCS();
    transfer(buffer, len);
    endTransactionWithDeassertingCS();

#ifdef DEBUG_SERIAL
    DEBUG_SERIAL.print(F("\tSPIDevice Read: "));
    for (uint16_t i = 0; i < len; i++)
    {
        DEBUG_SERIAL.print(F("0x"));
        DEBUG_SERIAL.print(buffer[i], HEX);
        DEBUG_SERIAL.print(F(", "));
        if (len % 32 == 31)
        {
            DEBUG_SERIAL.println();
        }
    }
    DEBUG_SERIAL.println();
#endif

    return true;
}

/*!
 *    @brief  Write some data, then read some data from SPI into another buffer,
 * with transaction management. The buffers can point to same/overlapping
 * locations. This does not transmit-receive at the same time!
 *    @param  write_buffer Pointer to buffer of data to write from
 *    @param  write_len Number of bytes from buffer to write.
 *    @param  read_buffer Pointer to buffer of data to read into.
 *    @param  read_len Number of bytes from buffer to read.
 *    @param  sendvalue The 8-bits of data to write when doing the data read,
 * defaults to 0xFF
 *    @return Always returns true because there's no way to test success of SPI
 * writes
 */
bool Adafruit_SPIDevice::write_then_read(const uint8_t *write_buffer,
                                         size_t write_len, uint8_t *read_buffer,
                                         size_t read_len, uint8_t sendvalue)
{
    beginTransactionWithAssertingCS();
    // do the writing
#if defined(ARDUINO_ARCH_ESP32)
    if (_spi)
    {
        if (write_len > 0)
        {
            _spi->transferBytes((uint8_t *)write_buffer, nullptr, write_len);
        }
    }
    else
#endif
    {
        for (size_t i = 0; i < write_len; i++)
        {
            transfer(write_buffer[i]);
        }
    }

#ifdef DEBUG_SERIAL
    DEBUG_SERIAL.print(F("\tSPIDevice Wrote: "));
    for (uint16_t i = 0; i < write_len; i++)
    {
        DEBUG_SERIAL.print(F("0x"));
        DEBUG_SERIAL.print(write_buffer[i], HEX);
        DEBUG_SERIAL.print(F(", "));
        if (write_len % 32 == 31)
        {
            DEBUG_SERIAL.println();
        }
    }
    DEBUG_SERIAL.println();
#endif

    // do the reading
    for (size_t i = 0; i < read_len; i++)
    {
        read_buffer[i] = transfer(sendvalue);
    }

#ifdef DEBUG_SERIAL
    DEBUG_SERIAL.print(F("\tSPIDevice Read: "));
    for (uint16_t i = 0; i < read_len; i++)
    {
        DEBUG_SERIAL.print(F("0x"));
        DEBUG_SERIAL.print(read_buffer[i], HEX);
        DEBUG_SERIAL.print(F(", "));
        if (read_len % 32 == 31)
        {
            DEBUG_SERIAL.println();
        }
    }
    DEBUG_SERIAL.println();
#endif

    endTransactionWithDeassertingCS();

    return true;
}

/*!
 *    @brief  Write some data and read some data at the same time from SPI
 * into the same buffer, with transaction management. This is basicaly a wrapper
 * for transfer() with CS-pin and transaction management. This /does/
 * transmit-receive at the same time!
 *    @param  buffer Pointer to buffer of data to write/read to/from
 *    @param  len Number of bytes from buffer to write/read.
 *    @return Always returns true because there's no way to test success of SPI
 * writes
 */
bool Adafruit_SPIDevice::write_and_read(uint8_t *buffer, size_t len)
{
    beginTransactionWithAssertingCS();
    transfer(buffer, len);
    endTransactionWithDeassertingCS();

    return true;
}