Adafruit_SPIDevice.cpp

#include "Adafruit_SPIDevice.h"

#if !defined(SPI_INTERFACES_COUNT) ||                                          \
    (defined(SPI_INTERFACES_COUNT) && (SPI_INTERFACES_COUNT > 0))

//#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) {
  _cs = cspin;
  _sck = _mosi = _miso = -1;
  _spi = theSPI;
  _begun = false;
  _spiSetting = new SPISettings(freq, dataOrder, dataMode);
  _freq = freq;
  _dataOrder = dataOrder;
  _dataMode = dataMode;
}

/*!
 *    @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;
  _spiSetting = new SPISettings(freq, dataOrder, dataMode);
  _spi = NULL;
}

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

/*!
 *    @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) {
  pinMode(_cs, OUTPUT);
  digitalWrite(_cs, HIGH);

  if (_spi) { // hardware SPI
    _spi->begin();
  } 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;
}

/*!
 *    @brief  Transfer (send/receive) one byte over hard/soft SPI
 *    @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) {
  if (_spi) {
    // hardware SPI is easy

#if defined(SPARK)
    _spi->transfer(buffer, buffer, len, NULL);
#elif defined(STM32)
    for (size_t i = 0; i < len; i++) {
      _spi->transfer(buffer[i]);
    }
#else
    _spi->transfer(buffer, len);
#endif
    return;
  }

  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 softSPI we'll do it by hand
  for (size_t i = 0; i < len; i++) {
    // software SPI
    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 |= mosiPinMask;
          else
            *mosiPort &= ~mosiPinMask;
#else
          digitalWrite(_mosi, towrite);
#endif
          lastmosi = towrite;
        }

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

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

#ifdef BUSIO_USE_FAST_PINIO
        *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
 *    @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) {
    _spi->beginTransaction(*_spiSetting);
  }
}

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

/*!
 *    @brief  Write a buffer or two to the SPI device.
 *    @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(uint8_t *buffer, size_t len,
                               uint8_t *prefix_buffer, size_t prefix_len) {
  if (_spi) {
    _spi->beginTransaction(*_spiSetting);
  }

  digitalWrite(_cs, LOW);
  // do the writing
  for (size_t i = 0; i < prefix_len; i++) {
    transfer(prefix_buffer[i]);
  }
  for (size_t i = 0; i < len; i++) {
    transfer(buffer[i]);
  }
  digitalWrite(_cs, HIGH);

  if (_spi) {
    _spi->endTransaction();
  }

#ifdef DEBUG_SERIAL
  DEBUG_SERIAL.print(F("\tSPIDevice Wrote: "));
  if ((prefix_len != 0) && (prefix_buffer != NULL)) {
    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.
 *    @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
  if (_spi) {
    _spi->beginTransaction(*_spiSetting);
  }
  digitalWrite(_cs, LOW);
  transfer(buffer, len);
  digitalWrite(_cs, HIGH);

  if (_spi) {
    _spi->endTransaction();
  }

#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.
 * 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(uint8_t *write_buffer,
                                         size_t write_len, uint8_t *read_buffer,
                                         size_t read_len, uint8_t sendvalue) {
  if (_spi) {
    _spi->beginTransaction(*_spiSetting);
  }

  digitalWrite(_cs, LOW);
  // do the writing
  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

  digitalWrite(_cs, HIGH);

  if (_spi) {
    _spi->endTransaction();
  }

  return true;
}

#endif // SPI exists