text: /**
   * Copyright (c) 2015 - 2021, Nordic Semiconductor ASA
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
   *    such product, must reproduce the above copyright notice, this list of
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   *
   * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
   *    contributors may be used to endorse or promote products derived from this
   *    software without specific prior written permission.
   *
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
   *
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   *    engineered, decompiled, modified and/or disassembled.
   *
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   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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   */
  
  #ifndef NRF_SPI_H__
  #define NRF_SPI_H__
  
  #include <nrfx.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * @defgroup nrf_spi_hal SPI HAL
   * @{
   * @ingroup nrf_spi
   * @brief   Hardware access layer for managing the SPI peripheral.
   */
  
  /**
   * @brief This value can be used as a parameter for the @ref nrf_spi_pins_set
   *        function to specify that a given SPI signal (SCK, MOSI, or MISO)
   *        shall not be connected to a physical pin.
   */
  #define NRF_SPI_PIN_NOT_CONNECTED  0xFFFFFFFF
  
  
  /** @brief SPI events. */
  typedef enum
  {
      NRF_SPI_EVENT_READY = offsetof(NRF_SPI_Type, EVENTS_READY) ///< TXD byte sent and RXD byte received.
  } nrf_spi_event_t;
  
  /** @brief SPI interrupts. */
  typedef enum
  {
      NRF_SPI_INT_READY_MASK = SPI_INTENSET_READY_Msk, ///< Interrupt on READY event.
      NRF_SPI_ALL_INTS_MASK  = SPI_INTENSET_READY_Msk  ///< All SPI interrupts.
  } nrf_spi_int_mask_t;
  
  /** @brief SPI data rates. */
  typedef enum
  {
      NRF_SPI_FREQ_125K = SPI_FREQUENCY_FREQUENCY_K125,   ///< 125 kbps.
      NRF_SPI_FREQ_250K = SPI_FREQUENCY_FREQUENCY_K250,   ///< 250 kbps.
      NRF_SPI_FREQ_500K = SPI_FREQUENCY_FREQUENCY_K500,   ///< 500 kbps.
      NRF_SPI_FREQ_1M   = SPI_FREQUENCY_FREQUENCY_M1,     ///< 1 Mbps.
      NRF_SPI_FREQ_2M   = SPI_FREQUENCY_FREQUENCY_M2,     ///< 2 Mbps.
      NRF_SPI_FREQ_4M   = SPI_FREQUENCY_FREQUENCY_M4,     ///< 4 Mbps.
      // [conversion to 'int' needed to prevent compilers from complaining
      //  that the provided value (0x80000000UL) is out of range of "int"]
      NRF_SPI_FREQ_8M   = (int)SPI_FREQUENCY_FREQUENCY_M8 ///< 8 Mbps.
  } nrf_spi_frequency_t;
  
  /** @brief SPI modes. */
  typedef enum
  {
      NRF_SPI_MODE_0, ///< SCK active high, sample on leading edge of clock.
      NRF_SPI_MODE_1, ///< SCK active high, sample on trailing edge of clock.
      NRF_SPI_MODE_2, ///< SCK active low, sample on leading edge of clock.
      NRF_SPI_MODE_3  ///< SCK active low, sample on trailing edge of clock.
  } nrf_spi_mode_t;
  
  /** @brief SPI bit orders. */
  typedef enum
  {
      NRF_SPI_BIT_ORDER_MSB_FIRST = SPI_CONFIG_ORDER_MsbFirst, ///< Most significant bit shifted out first.
      NRF_SPI_BIT_ORDER_LSB_FIRST = SPI_CONFIG_ORDER_LsbFirst  ///< Least significant bit shifted out first.
  } nrf_spi_bit_order_t;
  
  
  /**
   * @brief Function for clearing the specified SPI event.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   * @param[in] event Event to be cleared.
   */
  __STATIC_INLINE void nrf_spi_event_clear(NRF_SPI_Type *  p_reg,
                                           nrf_spi_event_t event);
  
  /**
   * @brief Function for retrieving the state of the SPI event.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   * @param[in] event Event to be checked.
   *
   * @retval true  The event has been generated.
   * @retval false The event has not been generated.
   */
  __STATIC_INLINE bool nrf_spi_event_check(NRF_SPI_Type *  p_reg,
                                           nrf_spi_event_t event);
  
  /**
   * @brief Function for getting the address of the specified SPI event register.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   * @param[in] event The specified event.
   *
   * @return Address of the specified event register.
   */
  __STATIC_INLINE uint32_t * nrf_spi_event_address_get(NRF_SPI_Type *  p_reg,
                                                       nrf_spi_event_t event);
  
  /**
   * @brief Function for enabling the specified interrupts.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   * @param[in] mask  Mask of interrupts to be enabled.
   */
  __STATIC_INLINE void nrf_spi_int_enable(NRF_SPI_Type * p_reg,
                                          uint32_t       mask);
  
  /**
   * @brief Function for disabling the specified interrupts.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   * @param[in] mask  Mask of interrupts to be disabled.
   */
  __STATIC_INLINE void nrf_spi_int_disable(NRF_SPI_Type * p_reg,
                                           uint32_t       mask);
  
  /**
   * @brief Function for retrieving the state of a given interrupt.
   *
   * @param[in] p_reg   Pointer to the structure of registers of the peripheral.
   * @param[in] spi_int Interrupt to be checked.
   *
   * @retval true  The interrupt is enabled.
   * @retval false The interrupt is not enabled.
   */
  __STATIC_INLINE bool nrf_spi_int_enable_check(NRF_SPI_Type *     p_reg,
                                                nrf_spi_int_mask_t spi_int);
  
  /**
   * @brief Function for enabling the SPI peripheral.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   */
  __STATIC_INLINE void nrf_spi_enable(NRF_SPI_Type * p_reg);
  
  /**
   * @brief Function for disabling the SPI peripheral.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   */
  __STATIC_INLINE void nrf_spi_disable(NRF_SPI_Type * p_reg);
  
  /**
   * @brief Function for configuring SPI pins.
   *
   * If a given signal is not needed, pass the @ref NRF_SPI_PIN_NOT_CONNECTED
   * value instead of its pin number.
   *
   * @param[in] p_reg    Pointer to the structure of registers of the peripheral.
   * @param[in] sck_pin  SCK pin number.
   * @param[in] mosi_pin MOSI pin number.
   * @param[in] miso_pin MISO pin number.
   */
  __STATIC_INLINE void nrf_spi_pins_set(NRF_SPI_Type * p_reg,
                                        uint32_t       sck_pin,
                                        uint32_t       mosi_pin,
                                        uint32_t       miso_pin);
  
  /**
   * @brief Function for writing data to the SPI transmitter register.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   * @param[in] data  TX data to send.
   */
  __STATIC_INLINE void nrf_spi_txd_set(NRF_SPI_Type * p_reg, uint8_t data);
  
  /**
   * @brief Function for reading data from the SPI receiver register.
   *
   * @param[in] p_reg Pointer to the structure of registers of the peripheral.
   *
   * @return RX data received.
   */
  __STATIC_INLINE uint8_t nrf_spi_rxd_get(NRF_SPI_Type * p_reg);
  
  /**
   * @brief Function for setting the SPI master data rate.
   *
   * @param[in] p_reg     Pointer to the structure of registers of the peripheral.
   * @param[in] frequency SPI frequency.
   */
  __STATIC_INLINE void nrf_spi_frequency_set(NRF_SPI_Type *      p_reg,
                                             nrf_spi_frequency_t frequency);
  
  /**
   * @brief Function for setting the SPI configuration.
   *
   * @param[in] p_reg         Pointer to the structure of registers of the peripheral.
   * @param[in] spi_mode      SPI mode.
   * @param[in] spi_bit_order SPI bit order.
   */
  __STATIC_INLINE void nrf_spi_configure(NRF_SPI_Type *      p_reg,
                                         nrf_spi_mode_t      spi_mode,
                                         nrf_spi_bit_order_t spi_bit_order);
  
  
  #ifndef SUPPRESS_INLINE_IMPLEMENTATION
  
  __STATIC_INLINE void nrf_spi_event_clear(NRF_SPI_Type *  p_reg,
                                           nrf_spi_event_t event)
  {
      *((volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)event)) = 0x0UL;
  #if __CORTEX_M == 0x04
      volatile uint32_t dummy = *((volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)event));
      (void)dummy;
  #endif
  }
  
  __STATIC_INLINE bool nrf_spi_event_check(NRF_SPI_Type *  p_reg,
                                           nrf_spi_event_t event)
  {
      return (bool)*(volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)event);
  }
  
  __STATIC_INLINE uint32_t * nrf_spi_event_address_get(NRF_SPI_Type *  p_reg,
                                                       nrf_spi_event_t event)
  {
      return (uint32_t *)((uint8_t *)p_reg + (uint32_t)event);
  }
  
  __STATIC_INLINE void nrf_spi_int_enable(NRF_SPI_Type * p_reg,
                                          uint32_t       mask)
  {
      p_reg->INTENSET = mask;
  }
  
  __STATIC_INLINE void nrf_spi_int_disable(NRF_SPI_Type * p_reg,
                                           uint32_t       mask)
  {
      p_reg->INTENCLR = mask;
  }
  
  __STATIC_INLINE bool nrf_spi_int_enable_check(NRF_SPI_Type *     p_reg,
                                                nrf_spi_int_mask_t spi_int)
  {
      return (bool)(p_reg->INTENSET & spi_int);
  }
  
  __STATIC_INLINE void nrf_spi_enable(NRF_SPI_Type * p_reg)
  {
      p_reg->ENABLE = (SPI_ENABLE_ENABLE_Enabled << SPI_ENABLE_ENABLE_Pos);
  }
  
  __STATIC_INLINE void nrf_spi_disable(NRF_SPI_Type * p_reg)
  {
      p_reg->ENABLE = (SPI_ENABLE_ENABLE_Disabled << SPI_ENABLE_ENABLE_Pos);
  }
  
  __STATIC_INLINE void nrf_spi_pins_set(NRF_SPI_Type * p_reg,
                                        uint32_t       sck_pin,
                                        uint32_t       mosi_pin,
                                        uint32_t       miso_pin)
  {
  #if defined(SPI_PSEL_SCK_CONNECT_Pos)
      p_reg->PSEL.SCK = sck_pin;
  #else
      p_reg->PSELSCK  = sck_pin;
  #endif
  
  #if defined(SPI_PSEL_MOSI_CONNECT_Pos)
      p_reg->PSEL.MOSI = mosi_pin;
  #else
      p_reg->PSELMOSI = mosi_pin;
  #endif
  
  #if defined(SPI_PSEL_MISO_CONNECT_Pos)
      p_reg->PSEL.MISO = miso_pin;
  #else
      p_reg->PSELMISO = miso_pin;
  #endif
  }
  
  __STATIC_INLINE void nrf_spi_txd_set(NRF_SPI_Type * p_reg, uint8_t data)
  {
      p_reg->TXD = data;
  }
  
  __STATIC_INLINE uint8_t nrf_spi_rxd_get(NRF_SPI_Type * p_reg)
  {
      return p_reg->RXD;
  }
  
  __STATIC_INLINE void nrf_spi_frequency_set(NRF_SPI_Type *      p_reg,
                                             nrf_spi_frequency_t frequency)
  {
      p_reg->FREQUENCY = frequency;
  }
  
  __STATIC_INLINE void nrf_spi_configure(NRF_SPI_Type *      p_reg,
                                         nrf_spi_mode_t      spi_mode,
                                         nrf_spi_bit_order_t spi_bit_order)
  {
      uint32_t config = (spi_bit_order == NRF_SPI_BIT_ORDER_MSB_FIRST ?
          SPI_CONFIG_ORDER_MsbFirst : SPI_CONFIG_ORDER_LsbFirst);
      switch (spi_mode)
      {
      default:
      case NRF_SPI_MODE_0:
          config |= (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos) |
                    (SPI_CONFIG_CPHA_Leading    << SPI_CONFIG_CPHA_Pos);
          break;
  
      case NRF_SPI_MODE_1:
          config |= (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos) |
                    (SPI_CONFIG_CPHA_Trailing   << SPI_CONFIG_CPHA_Pos);
          break;
  
      case NRF_SPI_MODE_2:
          config |= (SPI_CONFIG_CPOL_ActiveLow  << SPI_CONFIG_CPOL_Pos) |
                    (SPI_CONFIG_CPHA_Leading    << SPI_CONFIG_CPHA_Pos);
          break;
  
      case NRF_SPI_MODE_3:
          config |= (SPI_CONFIG_CPOL_ActiveLow  << SPI_CONFIG_CPOL_Pos) |
                    (SPI_CONFIG_CPHA_Trailing   << SPI_CONFIG_CPHA_Pos);
          break;
      }
      p_reg->CONFIG = config;
  }
  
  #endif // SUPPRESS_INLINE_IMPLEMENTATION
  
  /** @} */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif // NRF_SPI_H__
  