text: /*
      ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio
  
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
  
          http://www.apache.org/licenses/LICENSE-2.0
  
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.
  */
  
  /**
   * @file    hal_spi.h
   * @brief   SPI Driver macros and structures.
   *
   * @addtogroup SPI
   * @{
   */
  
  #ifndef HAL_SPI_H
  #define HAL_SPI_H
  
  #if (HAL_USE_SPI == TRUE) || defined(__DOXYGEN__)
  
  /*===========================================================================*/
  /* Driver constants.                                                         */
  /*===========================================================================*/
  
  /**
   * @name    Chip Select modes
   * @{
   */
  #define SPI_SELECT_MODE_NONE                0   /** @brief @p spiSelect() and
                                                      @p spiUnselect() do
                                                      nothing.                */
  #define SPI_SELECT_MODE_PAD                 1   /** @brief Legacy mode.     */
  #define SPI_SELECT_MODE_PORT                2   /** @brief Fastest mode.    */
  #define SPI_SELECT_MODE_LINE                3   /** @brief Packed mode.     */
  #define SPI_SELECT_MODE_LLD                 4   /** @brief LLD-defined mode.*/
  /** @} */
  
  /*===========================================================================*/
  /* Driver pre-compile time settings.                                         */
  /*===========================================================================*/
  
  /**
   * @name    SPI configuration options
   * @{
   */
  /**
   * @brief   Enables synchronous APIs.
   * @note    Disabling this option saves both code and data space.
   */
  #if !defined(SPI_USE_WAIT) || defined(__DOXYGEN__)
  #define SPI_USE_WAIT                        TRUE
  #endif
  
  /**
   * @brief   Enables circular transfers APIs.
   * @note    Disabling this option saves both code and data space.
   */
  #if !defined(SPI_USE_CIRCULAR) || defined(__DOXYGEN__)
  #define SPI_USE_CIRCULAR                    FALSE
  #endif
  
  /**
   * @brief   Enables the @p spiAcquireBus() and @p spiReleaseBus() APIs.
   * @note    Disabling this option saves both code and data space.
   */
  #if !defined(SPI_USE_MUTUAL_EXCLUSION) || defined(__DOXYGEN__)
  #define SPI_USE_MUTUAL_EXCLUSION            TRUE
  #endif
  
  /**
   * @brief   Handling method for SPI CS line.
   * @note    Disabling this option saves both code and data space.
   */
  #if !defined(SPI_SELECT_MODE) || defined(__DOXYGEN__)
  #define SPI_SELECT_MODE                     SPI_SELECT_MODE_PAD
  #endif
  /** @} */
  
  /*===========================================================================*/
  /* Derived constants and error checks.                                       */
  /*===========================================================================*/
  
  #if (SPI_SELECT_MODE != SPI_SELECT_MODE_NONE) &&                            \
      (SPI_SELECT_MODE != SPI_SELECT_MODE_PAD)  &&                            \
      (SPI_SELECT_MODE != SPI_SELECT_MODE_PORT) &&                            \
      (SPI_SELECT_MODE != SPI_SELECT_MODE_LINE) &&                            \
      (SPI_SELECT_MODE != SPI_SELECT_MODE_LLD)
  #error "invalid SPI_SELECT_MODE setting"
  #endif
  
  /* Some modes have a dependency on the PAL driver, making the required
     checks here.*/
  #if ((SPI_SELECT_MODE != SPI_SELECT_MODE_PAD)  ||                           \
       (SPI_SELECT_MODE != SPI_SELECT_MODE_PORT) ||                           \
       (SPI_SELECT_MODE != SPI_SELECT_MODE_LINE)) &&                          \
      (HAL_USE_PAL != TRUE)
  #error "current SPI_SELECT_MODE requires HAL_USE_PAL"
  #endif
  
  /*===========================================================================*/
  /* Driver data structures and types.                                         */
  /*===========================================================================*/
  
  /**
   * @brief   Driver state machine possible states.
   */
  typedef enum {
    SPI_UNINIT = 0,                   /**< Not initialized.                   */
    SPI_STOP = 1,                     /**< Stopped.                           */
    SPI_READY = 2,                    /**< Ready.                             */
    SPI_ACTIVE = 3,                   /**< Exchanging data.                   */
    SPI_COMPLETE = 4                  /**< Asynchronous operation complete.   */
  } spistate_t;
  
  /**
   * @brief   Type of a structure representing an SPI driver.
   */
  typedef struct hal_spi_driver SPIDriver;
  /**
   * @brief   Type of a SPI driver configuration structure.
   */
  typedef struct hal_spi_config SPIConfig;
  
  /**
   * @brief   SPI notification callback type.
   *
   * @param[in] spip      pointer to the @p SPIDriver object triggering the
   *                      callback
   */
  typedef void (*spicallback_t)(SPIDriver *spip);
  
  /* Including the low level driver header, it exports information required
     for completing types.*/
  #include "hal_spi_lld.h"
  
  /**
   * @brief   Driver configuration structure.
   */
  struct hal_spi_config {
  #if (SPI_SUPPORTS_CIRCULAR == TRUE) || defined(__DOXYGEN__)
    /**
     * @brief   Enables the circular buffer mode.
     */
    bool                      circular;
  #endif
    /**
     * @brief Operation complete callback or @p NULL.
     */
    spicallback_t             end_cb;
  #if (SPI_SELECT_MODE == SPI_SELECT_MODE_LINE) || defined(__DOXYGEN__)
    /**
     * @brief The chip select line.
     */
    ioline_t                  ssline;
  #endif
  #if (SPI_SELECT_MODE == SPI_SELECT_MODE_PORT) || defined(__DOXYGEN__)
    /**
     * @brief The chip select port.
     */
    ioportid_t                ssport;
    /**
     * @brief The chip select port mask.
     */
    ioportmask_t              ssmask;
  #endif
  #if (SPI_SELECT_MODE == SPI_SELECT_MODE_PAD) || defined(__DOXYGEN__)
    /**
     * @brief The chip select port.
     */
    ioportid_t                ssport;
    /**
     * @brief The chip select pad number.
     */
    uint_fast8_t              sspad;
  #endif
    /* End of the mandatory fields.*/
    spi_lld_config_fields;
  };
  
  /**
   * @brief   Structure representing an SPI driver.
   */
  struct hal_spi_driver {
    /**
     * @brief Driver state.
     */
    spistate_t                state;
    /**
     * @brief Current configuration data.
     */
    const SPIConfig           *config;
  #if (SPI_USE_WAIT == TRUE) || defined(__DOXYGEN__)
    /**
     * @brief   Waiting thread.
     */
    thread_reference_t        thread;
  #endif /* SPI_USE_WAIT == TRUE */
  #if (SPI_USE_MUTUAL_EXCLUSION == TRUE) || defined(__DOXYGEN__)
    /**
     * @brief   Mutex protecting the peripheral.
     */
    mutex_t                   mutex;
  #endif /* SPI_USE_MUTUAL_EXCLUSION == TRUE */
  #if defined(SPI_DRIVER_EXT_FIELDS)
    SPI_DRIVER_EXT_FIELDS
  #endif
    /* End of the mandatory fields.*/
    spi_lld_driver_fields;
  };
  
  /*===========================================================================*/
  /* Driver macros.                                                            */
  /*===========================================================================*/
  
  /**
   * @name    Macro Functions
   * @{
   */
  /**
   * @brief   Buffer state.
   * @note    This function is meant to be called from the SPI callback only.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   * @return              The buffer state.
   * @retval              false if the driver filled/sent the first half of the
   *                      buffer.
   * @retval              true if the driver filled/sent the second half of the
   *                      buffer.
   *
   * @special
   */
  #define spiIsBufferComplete(spip) ((bool)((spip)->state == SPI_COMPLETE))
  
  #if (SPI_SELECT_MODE == SPI_SELECT_MODE_LLD) || defined(__DOXYGEN__)
  /**
   * @brief   Asserts the slave select signal and prepares for transfers.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   *
   * @iclass
   */
  #define spiSelectI(spip)                                                    \
  do {                                                                        \
    spi_lld_select(spip);                                                     \
  } while (false)
  
  /**
   * @brief   Deasserts the slave select signal.
   * @details The previously selected peripheral is unselected.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   *
   * @iclass
   */
  #define spiUnselectI(spip)                                                  \
  do {                                                                        \
    spi_lld_unselect(spip);                                                   \
  } while (false)
  
  #elif SPI_SELECT_MODE == SPI_SELECT_MODE_LINE
  #define spiSelectI(spip)                                                    \
  do {                                                                        \
    palClearLine((spip)->config->ssline);                                     \
  } while (false)
  
  #define spiUnselectI(spip)                                                  \
  do {                                                                        \
    palSetLine((spip)->config->ssline);                                       \
  } while (false)
  
  #elif SPI_SELECT_MODE == SPI_SELECT_MODE_PORT
  #define spiSelectI(spip)                                                    \
  do {                                                                        \
    palClearPort((spip)->config->ssport, (spip)->config->ssmask);             \
  } while (false)
  
  #define spiUnselectI(spip)                                                  \
  do {                                                                        \
    palSetPort((spip)->config->ssport, (spip)->config->ssmask);               \
  } while (false)
  
  #elif SPI_SELECT_MODE == SPI_SELECT_MODE_PAD
  #define spiSelectI(spip)                                                    \
  do {                                                                        \
    palClearPad((spip)->config->ssport, (spip)->config->sspad);               \
  } while (false)
  
  #define spiUnselectI(spip)                                                  \
  do {                                                                        \
    palSetPad((spip)->config->ssport, (spip)->config->sspad);                 \
  } while (false)
  
  #elif SPI_SELECT_MODE == SPI_SELECT_MODE_NONE
  #define spiSelectI(spip)
  
  #define spiUnselectI(spip)
  #endif
  
  /**
   * @brief   Ignores data on the SPI bus.
   * @details This asynchronous function starts the transmission of a series of
   *          idle words on the SPI bus and ignores the received data.
   * @pre     A slave must have been selected using @p spiSelect() or
   *          @p spiSelectI().
   * @post    At the end of the operation the configured callback is invoked.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   * @param[in] n         number of words to be ignored
   *
   * @iclass
   */
  #define spiStartIgnoreI(spip, n) {                                          \
    (spip)->state = SPI_ACTIVE;                                               \
    spi_lld_ignore(spip, n);                                                  \
  }
  
  /**
   * @brief   Exchanges data on the SPI bus.
   * @details This asynchronous function starts a simultaneous transmit/receive
   *          operation.
   * @pre     A slave must have been selected using @p spiSelect() or
   *          @p spiSelectI().
   * @post    At the end of the operation the configured callback is invoked.
   * @note    The buffers are organized as uint8_t arrays for data sizes below
   *          or equal to 8 bits else it is organized as uint16_t arrays.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   * @param[in] n         number of words to be exchanged
   * @param[in] txbuf     the pointer to the transmit buffer
   * @param[out] rxbuf    the pointer to the receive buffer
   *
   * @iclass
   */
  #define spiStartExchangeI(spip, n, txbuf, rxbuf) {                          \
    (spip)->state = SPI_ACTIVE;                                               \
    spi_lld_exchange(spip, n, txbuf, rxbuf);                                  \
  }
  
  /**
   * @brief   Sends data over the SPI bus.
   * @details This asynchronous function starts a transmit operation.
   * @pre     A slave must have been selected using @p spiSelect() or
   *          @p spiSelectI().
   * @post    At the end of the operation the configured callback is invoked.
   * @note    The buffers are organized as uint8_t arrays for data sizes below
   *          or equal to 8 bits else it is organized as uint16_t arrays.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   * @param[in] n         number of words to send
   * @param[in] txbuf     the pointer to the transmit buffer
   *
   * @iclass
   */
  #define spiStartSendI(spip, n, txbuf) {                                     \
    (spip)->state = SPI_ACTIVE;                                               \
    spi_lld_send(spip, n, txbuf);                                             \
  }
  
  /**
   * @brief   Receives data from the SPI bus.
   * @details This asynchronous function starts a receive operation.
   * @pre     A slave must have been selected using @p spiSelect() or
   *          @p spiSelectI().
   * @post    At the end of the operation the configured callback is invoked.
   * @note    The buffers are organized as uint8_t arrays for data sizes below
   *          or equal to 8 bits else it is organized as uint16_t arrays.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   * @param[in] n         number of words to receive
   * @param[out] rxbuf    the pointer to the receive buffer
   *
   * @iclass
   */
  #define spiStartReceiveI(spip, n, rxbuf) {                                  \
    (spip)->state = SPI_ACTIVE;                                               \
    spi_lld_receive(spip, n, rxbuf);                                          \
  }
  
  /**
   * @brief   Exchanges one frame using a polled wait.
   * @details This synchronous function exchanges one frame using a polled
   *          synchronization method. This function is useful when exchanging
   *          small amount of data on high speed channels, usually in this
   *          situation is much more efficient just wait for completion using
   *          polling than suspending the thread waiting for an interrupt.
   * @note    This API is implemented as a macro in order to minimize latency.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   * @param[in] frame     the data frame to send over the SPI bus
   * @return              The received data frame from the SPI bus.
   */
  #define spiPolledExchange(spip, frame) spi_lld_polled_exchange(spip, frame)
  /** @} */
  
  /**
   * @name    Low level driver helper macros
   * @{
   */
  #if (SPI_USE_WAIT == TRUE) || defined(__DOXYGEN__)
  /**
   * @brief   Wakes up the waiting thread.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   *
   * @notapi
   */
  #define _spi_wakeup_isr(spip) {                                             \
    osalSysLockFromISR();                                                     \
    osalThreadResumeI(&(spip)->thread, MSG_OK);                               \
    osalSysUnlockFromISR();                                                   \
  }
  #else /* !SPI_USE_WAIT */
  #define _spi_wakeup_isr(spip)
  #endif /* !SPI_USE_WAIT */
  
  /**
   * @brief   Common ISR code when circular mode is not supported.
   * @details This code handles the portable part of the ISR code:
   *          - Callback invocation.
   *          - Waiting thread wakeup, if any.
   *          - Driver state transitions.
   *          .
   * @note    This macro is meant to be used in the low level drivers
   *          implementation only.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   *
   * @notapi
   */
  #define _spi_isr_code(spip) {                                               \
    if ((spip)->config->end_cb) {                                             \
      (spip)->state = SPI_COMPLETE;                                           \
      (spip)->config->end_cb(spip);                                           \
      if ((spip)->state == SPI_COMPLETE)                                      \
        (spip)->state = SPI_READY;                                            \
    }                                                                         \
    else                                                                      \
      (spip)->state = SPI_READY;                                              \
    _spi_wakeup_isr(spip);                                                    \
  }
  
  /**
   * @brief   Half buffer filled ISR code in circular mode.
   * @details This code handles the portable part of the ISR code:
   *          - Callback invocation.
   *          .
   * @note    This macro is meant to be used in the low level drivers
   *          implementation only.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   *
   * @notapi
   */
  #define _spi_isr_half_code(spip) {                                          \
    if ((spip)->config->end_cb) {                                             \
      (spip)->config->end_cb(spip);                                           \
    }                                                                         \
  }
  
  /**
   * @brief   Full buffer filled ISR code in circular mode.
   * @details This code handles the portable part of the ISR code:
   *          - Callback invocation.
   *          - Driver state transitions.
   *          .
   * @note    This macro is meant to be used in the low level drivers
   *          implementation only.
   *
   * @param[in] spip      pointer to the @p SPIDriver object
   *
   * @notapi
   */
  #define _spi_isr_full_code(spip) {                                          \
    if ((spip)->config->end_cb) {                                             \
      (spip)->state = SPI_COMPLETE;                                           \
      (spip)->config->end_cb(spip);                                           \
      if ((spip)->state == SPI_COMPLETE)                                      \
        (spip)->state = SPI_ACTIVE;                                           \
    }                                                                         \
  }
  /** @} */
  
  /*===========================================================================*/
  /* External declarations.                                                    */
  /*===========================================================================*/
  
  #ifdef __cplusplus
  extern "C" {
  #endif
    void spiInit(void);
    void spiObjectInit(SPIDriver *spip);
    void spiStart(SPIDriver *spip, const SPIConfig *config);
    void spiStop(SPIDriver *spip);
    void spiSelect(SPIDriver *spip);
    void spiUnselect(SPIDriver *spip);
    void spiStartIgnore(SPIDriver *spip, size_t n);
    void spiStartExchange(SPIDriver *spip, size_t n,
                          const void *txbuf, void *rxbuf);
    void spiStartSend(SPIDriver *spip, size_t n, const void *txbuf);
    void spiStartReceive(SPIDriver *spip, size_t n, void *rxbuf);
  #if SPI_SUPPORTS_CIRCULAR == TRUE
    void spiAbortI(SPIDriver *spip);
    void spiAbort(SPIDriver *spip);
  #endif
  #if SPI_USE_WAIT == TRUE
    void spiIgnore(SPIDriver *spip, size_t n);
    void spiExchange(SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf);
    void spiSend(SPIDriver *spip, size_t n, const void *txbuf);
    void spiReceive(SPIDriver *spip, size_t n, void *rxbuf);
  #endif
  #if SPI_USE_MUTUAL_EXCLUSION == TRUE
    void spiAcquireBus(SPIDriver *spip);
    void spiReleaseBus(SPIDriver *spip);
  #endif
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* HAL_USE_SPI == TRUE */
  
  #endif /* HAL_SPI_H */
  
  /** @} */
  