text: /**
   * Copyright (c) 2015 - 2019, 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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   *    materials provided with the distribution.
   *
   * 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.
   *
   * 5. Any software provided in binary form under this license must not be reverse
   *    engineered, decompiled, modified and/or disassembled.
   *
   * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
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   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
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   */
  
  #ifndef NRFX_QDEC_H__
  #define NRFX_QDEC_H__
  
  #include <nrfx.h>
  #include <hal/nrf_qdec.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * @defgroup nrfx_qdec QDEC driver
   * @{
   * @ingroup nrf_qdec
   * @brief   Quadrature Decoder (QDEC) peripheral driver.
   */
  
  /** @brief QDEC configuration structure. */
  typedef struct
  {
      nrf_qdec_reportper_t reportper;          /**< Report period in samples. */
      nrf_qdec_sampleper_t sampleper;          /**< Sampling period in microseconds. */
      uint32_t             psela;              /**< Pin number for A input. */
      uint32_t             pselb;              /**< Pin number for B input. */
      uint32_t             pselled;            /**< Pin number for LED output. */
      uint32_t             ledpre;             /**< Time (in microseconds) how long LED is switched on before sampling. */
      nrf_qdec_ledpol_t    ledpol;             /**< Active LED polarity. */
      bool                 dbfen;              /**< State of debouncing filter. */
      bool                 sample_inten;       /**< Enabling sample ready interrupt. */
      uint8_t              interrupt_priority; /**< QDEC interrupt priority. */
  } nrfx_qdec_config_t;
  
  /**@brief QDEC default configuration. */
  #define NRFX_QDEC_DEFAULT_CONFIG                                            \
  {                                                                           \
      .reportper          = (nrf_qdec_reportper_t)NRFX_QDEC_CONFIG_REPORTPER, \
      .sampleper          = (nrf_qdec_sampleper_t)NRFX_QDEC_CONFIG_SAMPLEPER, \
      .psela              = NRFX_QDEC_CONFIG_PIO_A,                           \
      .pselb              = NRFX_QDEC_CONFIG_PIO_B,                           \
      .pselled            = NRFX_QDEC_CONFIG_PIO_LED,                         \
      .ledpre             = NRFX_QDEC_CONFIG_LEDPRE,                          \
      .ledpol             = (nrf_qdec_ledpol_t)NRFX_QDEC_CONFIG_LEDPOL,       \
      .dbfen              = NRFX_QDEC_CONFIG_DBFEN,                           \
      .sample_inten       = NRFX_QDEC_CONFIG_SAMPLE_INTEN,                    \
      .interrupt_priority = NRFX_QDEC_CONFIG_IRQ_PRIORITY,                    \
  }
  
  /** @brief QDEC sample event data. */
  typedef struct
  {
      int8_t value; /**< Sample value. */
  } nrfx_qdec_sample_data_evt_t;
  
  /** @brief QDEC report event data. */
  typedef struct
  {
      int16_t acc;     /**< Accumulated transitions. */
      uint16_t accdbl; /**< Accumulated double transitions. */
  } nrfx_qdec_report_data_evt_t;
  
  /** @brief QDEC event handler structure. */
  typedef struct
  {
      nrf_qdec_event_t  type; /**< Event type. */
      union
      {
          nrfx_qdec_sample_data_evt_t sample; /**< Sample event data. */
          nrfx_qdec_report_data_evt_t report; /**< Report event data. */
      } data;                                 /**< Union to store event data. */
  } nrfx_qdec_event_t;
  
  /**
   * @brief QDEC event handler.
   *
   * @param[in] event QDEC event structure.
   */
  typedef void (*nrfx_qdec_event_handler_t)(nrfx_qdec_event_t event);
  
  /**
   * @brief Function for initializing QDEC.
   *
   * @param[in] p_config      Pointer to the structure with the initial configuration.
   * @param[in] event_handler Event handler provided by the user.
   *                          Must not be NULL.
   *
   * @retval NRFX_SUCCESS             Initialization was successful.
   * @retval NRFX_ERROR_INVALID_STATE The QDEC was already initialized.
   */
  nrfx_err_t nrfx_qdec_init(nrfx_qdec_config_t const * p_config,
                            nrfx_qdec_event_handler_t  event_handler);
  
  /**
   * @brief Function for uninitializing QDEC.
   *
   * @note Function asserts if module is uninitialized.
   */
  void nrfx_qdec_uninit(void);
  
  /**
   * @brief Function for enabling QDEC.
   *
   * @note Function asserts if module is uninitialized or enabled.
   */
  void nrfx_qdec_enable(void);
  
  /**
   * @brief Function for disabling QDEC.
   *
   * @note Function asserts if module is uninitialized or disabled.
   */
  void nrfx_qdec_disable(void);
  
  /**
   * @brief Function for reading accumulated transitions from the QDEC peripheral.
   *
   * @note Function asserts if module is not enabled.
   * @note Accumulators are cleared after reading.
   *
   * @param[out] p_acc    Pointer to store the accumulated transitions.
   * @param[out] p_accdbl Pointer to store the accumulated double transitions.
   */
  void nrfx_qdec_accumulators_read(int16_t * p_acc, int16_t * p_accdbl);
  
  /**
   * @brief Function for returning the address of the specified QDEC task.
   *
   * @param task QDEC task.
   *
   * @return Task address.
   */
  __STATIC_INLINE uint32_t nrfx_qdec_task_address_get(nrf_qdec_task_t task)
  {
      return (uint32_t)nrf_qdec_task_address_get(task);
  }
  
  /**
   * @brief Function for returning the address of the specified QDEC event.
   *
   * @param event QDEC event.
   *
   * @return Event address.
   */
  __STATIC_INLINE uint32_t nrfx_qdec_event_address_get(nrf_qdec_event_t event)
  {
      return (uint32_t)nrf_qdec_event_address_get(event);
  }
  
  /** @} */
  
  
  void nrfx_qdec_irq_handler(void);
  
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif // NRFX_QDEC_H__
  