STM32F4_SPI_DMA.h

/* Custom SPI library
 * This library inherits from the STM32 version and adds DMA support for STM32
 * F401. Additional DMA transfer functions are added. After each transfer DMA is
 * disabled, such that the normal transfer functions still work as well
 */
#ifndef STM32F4_SPI_DMA_H
#define STM32F4_SPI_DMA_H

#include <SPI.h>

class SPIDMAClass : public SPIClass {
 public:
  using SPIClass::SPIClass;

  void begin(uint8_t _pin = CS_PIN_CONTROLLED_BY_USER);
  void end();

  byte DMAtransfer(uint8_t pin, uint8_t _data,
                   SPITransferMode _mode = SPI_LAST);
  uint16_t DMAtransfer16(uint8_t pin, uint16_t _data,
                         SPITransferMode _mode = SPI_LAST);
  void DMAtransfer(uint8_t pin, void *_buf, size_t _count,
                   SPITransferMode _mode = SPI_LAST);
  // the byte type is not a typo, but matches the STM32 SPI library.
  void DMAtransfer(byte pin, void *_bufout, void *_bufin, size_t _count,
                   SPITransferMode _mode = SPI_LAST);

  byte DMAtransfer(uint8_t _data, SPITransferMode _mode = SPI_LAST) {
    return DMAtransfer(CS_PIN_CONTROLLED_BY_USER, _data, _mode);
  }
  uint16_t DMAtransfer16(uint16_t _data, SPITransferMode _mode = SPI_LAST) {
    return DMAtransfer16(CS_PIN_CONTROLLED_BY_USER, _data, _mode);
  }
  void DMAtransfer(void *_buf, size_t _count,
                   SPITransferMode _mode = SPI_LAST) {
    return DMAtransfer(CS_PIN_CONTROLLED_BY_USER, _buf, _count, _mode);
  }
  void DMAtransfer(void *_bufout, void *_bufin, size_t _count,
                   SPITransferMode _mode = SPI_LAST) {
    return DMAtransfer(CS_PIN_CONTROLLED_BY_USER, _bufout, _bufin, _count,
                       _mode);
  }

 private:
  DMA_TypeDef *_dma;
  uint32_t _txstream;
  uint32_t _txchannel;
  uint32_t (*LL_DMATX_IsActiveFlag_TC)(DMA_TypeDef *DMAx);
  void (*LL_DMATX_ClearFlag_TC)(DMA_TypeDef *DMAx);
};
#endif  // STM32F4_SPI_DMA_H