/*
  * start rewrite from:
  * https://github.com/arduino/ArduinoCore-mbed/blob/master/libraries/SPI/SPI.cpp
  */
 #ifdef ARDUINO_ARCH_NRF52840
 
 #include "Arduino_NRFXSPI.h"
 
 Arduino_NRFXSPI::Arduino_NRFXSPI(int8_t dc, int8_t cs /* = GFX_NOT_DEFINED */, int8_t sck /* = GFX_NOT_DEFINED */, int8_t mosi /* = GFX_NOT_DEFINED */, int8_t miso /* = GFX_NOT_DEFINED */)
     : _dc(dc), _cs(cs), _sck(sck), _mosi(mosi), _miso(miso)
 {
 }
 
 bool Arduino_NRFXSPI::begin(int32_t speed, int8_t dataMode)
 {
   _speed = (speed == GFX_NOT_DEFINED) ? SPI_DEFAULT_FREQ : speed;
   _dataMode = (dataMode == GFX_NOT_DEFINED) ? SPI_MODE2 : dataMode;
 
   // init pin mask
   uint32_t pin = digitalPinToPinName((pin_size_t)_dc);
   NRF_GPIO_Type *reg = nrf_gpio_pin_port_decode(&pin);
   nrf_gpio_cfg_output(pin);
   _dcPortSet = &reg->OUTSET;
   _dcPortClr = &reg->OUTCLR;
   _dcPinMask = 1UL << pin;
   if (_cs != GFX_NOT_DEFINED)
   {
     pin = digitalPinToPinName((pin_size_t)_cs);
     reg = nrf_gpio_pin_port_decode(&pin);
     nrf_gpio_cfg_output(pin);
     _csPortSet = &reg->OUTSET;
     _csPortClr = &reg->OUTCLR;
     _csPinMask = 1UL << pin;
   }
 
   // init SPI pins
   _nrfxSpiConfig.sck_pin = digitalPinToPinName((pin_size_t)_sck);
   _nrfxSpiConfig.mosi_pin = digitalPinToPinName((pin_size_t)_mosi);
   if (_miso > 0)
   {
     _nrfxSpiConfig.miso_pin = digitalPinToPinName((pin_size_t)_miso);
   }
   else
   {
     _nrfxSpiConfig.miso_pin = NRFX_SPI_PIN_NOT_USED;
   }
 
   // init speed
   if (_speed >= 8000000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_8M;
   }
   else if (_speed >= 4000000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_4M;
   }
   else if (_speed >= 2000000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_2M;
   }
   else if (_speed >= 1000000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_1M;
   }
   else if (_speed >= 500000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_500K;
   }
   else if (_speed >= 250000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_250K;
   }
   else if (_speed >= 125000)
   {
     _nrfxSpiConfig.frequency = NRF_SPI_FREQ_125K;
   }
 
   // init data mode
   if (_dataMode == SPI_MODE1)
   {
     _nrfxSpiConfig.mode = NRF_SPI_MODE_1;
   }
   else if (_dataMode == SPI_MODE2)
   {
     _nrfxSpiConfig.mode = NRF_SPI_MODE_2;
   }
   else if (_dataMode == SPI_MODE3)
   {
     _nrfxSpiConfig.mode = NRF_SPI_MODE_3;
   }
   else
   {
     _dataMode = SPI_MODE0;
     _nrfxSpiConfig.mode = NRF_SPI_MODE_0;
   }
 
   // init SPI
   nrfx_spi_init(&_nrfxSpi, &_nrfxSpiConfig, NULL, NULL);
 
   return true;
 }
 
 void Arduino_NRFXSPI::beginWrite()
 {
   DC_HIGH();
 
   CS_LOW();
 }
 
 void Arduino_NRFXSPI::endWrite()
 {
   CS_HIGH();
 }
 
 void Arduino_NRFXSPI::writeCommand(uint8_t c)
 {
   DC_LOW();
 
   WRITE(c);
 
   DC_HIGH();
 }
 
 void Arduino_NRFXSPI::writeCommand16(uint16_t c)
 {
   DC_LOW();
 
   WRITE16(c);
 
   DC_HIGH();
 }
 
 void Arduino_NRFXSPI::write(uint8_t d)
 {
   WRITE(d);
 }
 
 void Arduino_NRFXSPI::write16(uint16_t d)
 {
   WRITE16(d);
 }
 
 void Arduino_NRFXSPI::writeRepeat(uint16_t p, uint32_t len)
 {
   MSB_16_SET(p, p);
   uint32_t bufLen = (len < SPI_MAX_PIXELS_AT_ONCE) ? len : SPI_MAX_PIXELS_AT_ONCE;
   uint32_t xferLen;
   for (uint32_t i = 0; i < bufLen; i++)
   {
     _buffer16[i] = p;
   }
 
   while (len)
   {
     xferLen = (bufLen < len) ? bufLen : len;
     WRITEBUF(_buffer, xferLen * 2);
     len -= xferLen;
   }
 }
 
 void Arduino_NRFXSPI::writePixels(uint16_t *data, uint32_t len)
 {
   uint32_t xferLen;
   uint8_t *p;
   union
   {
     uint16_t val;
     struct
     {
       uint8_t lsb;
       uint8_t msb;
     };
   } t;
   while (len)
   {
     xferLen = (len < SPI_MAX_PIXELS_AT_ONCE) ? len : SPI_MAX_PIXELS_AT_ONCE;
     p = _buffer;
     for (uint32_t i = 0; i < xferLen; i++)
     {
       t.val = *data++;
       *p++ = t.msb;
       *p++ = t.lsb;
     }
     len -= xferLen;
 
     xferLen += xferLen; // uint16_t to uint8_t, double length
     WRITEBUF(_buffer, xferLen);
   }
 }
 
 void Arduino_NRFXSPI::writeC8D8(uint8_t c, uint8_t d)
 {
   DC_LOW();
 
   WRITE(c);
 
   DC_HIGH();
 
   WRITE(d);
 }
 
 void Arduino_NRFXSPI::writeC8D16(uint8_t c, uint16_t d)
 {
   DC_LOW();
 
   WRITE(c);
 
   DC_HIGH();
 
   WRITE16(d);
 }
 
 void Arduino_NRFXSPI::writeC8D16D16(uint8_t c, uint16_t d1, uint16_t d2)
 {
   DC_LOW();
 
   const nrfx_spi_xfer_desc_t xfer_desc1 = NRFX_SPI_SINGLE_XFER(&c, 1, NULL, 0);
   nrfx_spi_xfer(&_nrfxSpi, &xfer_desc1, 0);
 
   DC_HIGH();
 
   uint32_t d;
   MSB_32_16_16_SET(d, d1, d2);
   const nrfx_spi_xfer_desc_t xfer_desc2 = NRFX_SPI_SINGLE_XFER(&d, 4, NULL, 0);
   nrfx_spi_xfer(&_nrfxSpi, &xfer_desc2, 0);
 }
 
 void Arduino_NRFXSPI::writeBytes(uint8_t *data, uint32_t len)
 {
   WRITEBUF(data, len);
 }
 
 void Arduino_NRFXSPI::writePattern(uint8_t *data, uint8_t len, uint32_t repeat)
 {
   while (repeat--)
   {
     WRITEBUF(data, len);
   }
 }
 
 INLINE void Arduino_NRFXSPI::WRITE(uint8_t d)
 {
   const nrfx_spi_xfer_desc_t xfer_desc = NRFX_SPI_SINGLE_XFER(&d, 1, NULL, 0);
   nrfx_spi_xfer(&_nrfxSpi, &xfer_desc, 0);
 }
 
 INLINE void Arduino_NRFXSPI::WRITE16(uint16_t d)
 {
   MSB_16_SET(d, d);
   const nrfx_spi_xfer_desc_t xfer_desc = NRFX_SPI_SINGLE_XFER(&d, 2, NULL, 0);
   nrfx_spi_xfer(&_nrfxSpi, &xfer_desc, 0);
 }
 
 INLINE void Arduino_NRFXSPI::WRITEBUF(uint8_t *buf, size_t count)
 {
   const nrfx_spi_xfer_desc_t xfer_desc = NRFX_SPI_SINGLE_XFER(buf, count, NULL, 0);
   nrfx_spi_xfer(&_nrfxSpi, &xfer_desc, 0);
 }
 
 /******** low level bit twiddling **********/
 
 INLINE void Arduino_NRFXSPI::DC_HIGH(void)
 {
   *_dcPortSet = _dcPinMask;
 }
 
 INLINE void Arduino_NRFXSPI::DC_LOW(void)
 {
   *_dcPortClr = _dcPinMask;
 }
 
 INLINE void Arduino_NRFXSPI::CS_HIGH(void)
 {
   if (_cs != GFX_NOT_DEFINED)
   {
     *_csPortSet = _csPinMask;
   }
 }
 
 INLINE void Arduino_NRFXSPI::CS_LOW(void)
 {
   if (_cs != GFX_NOT_DEFINED)
   {
     *_csPortClr = _csPinMask;
   }
 }
 
 #endif // #ifdef ARDUINO_ARCH_NRF52840

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