text: /**
   * Copyright (c) 2015 - 2018, 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
   *    conditions and the following disclaimer in the documentation and/or other
   *    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
   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
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   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
   * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  #ifndef NRF_PDM_H_
  #define NRF_PDM_H_
  
  #include <nrfx.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * @defgroup nrf_pdm_hal PDM HAL
   * @{
   * @ingroup nrf_pdm
   * @brief   Hardware access layer for managing the Pulse Density Modulation (PDM) peripheral.
   */
  
  #define NRF_PDM_GAIN_MINIMUM  0x00
  #define NRF_PDM_GAIN_DEFAULT  0x28
  #define NRF_PDM_GAIN_MAXIMUM  0x50
  
  typedef uint8_t nrf_pdm_gain_t;
  
  
  /**
   * @brief PDM tasks.
   */
  typedef enum /*lint -save -e30 -esym(628,__INTADDR__) */
  {
      NRF_PDM_TASK_START           = offsetof(NRF_PDM_Type, TASKS_START),           ///< Starts continuous PDM transfer.
      NRF_PDM_TASK_STOP            = offsetof(NRF_PDM_Type, TASKS_STOP)             ///< Stops PDM transfer.
  } nrf_pdm_task_t;
  
  
  /**
   * @brief PDM events.
   */
  typedef enum /*lint -save -e30 -esym(628,__INTADDR__) */
  {
      NRF_PDM_EVENT_STARTED       = offsetof(NRF_PDM_Type, EVENTS_STARTED),       ///< PDM transfer has started.
      NRF_PDM_EVENT_STOPPED       = offsetof(NRF_PDM_Type, EVENTS_STOPPED),       ///< PDM transfer has finished.
      NRF_PDM_EVENT_END           = offsetof(NRF_PDM_Type, EVENTS_END)            ///< The PDM has written the last sample specified by SAMPLE.MAXCNT (or the last sample after a STOP task has been received) to Data RAM.
  } nrf_pdm_event_t;
  
  
  /**
   * @brief PDM interrupt masks.
   */
  typedef enum
  {
      NRF_PDM_INT_STARTED = PDM_INTENSET_STARTED_Msk,   ///< Interrupt on EVENTS_STARTED event.
      NRF_PDM_INT_STOPPED = PDM_INTENSET_STOPPED_Msk,   ///< Interrupt on EVENTS_STOPPED event.
      NRF_PDM_INT_END     = PDM_INTENSET_END_Msk        ///< Interrupt on EVENTS_END event.
  } nrf_pdm_int_mask_t;
  
  /**
   * @brief PDM clock frequency.
   */
  typedef enum
  {
      NRF_PDM_FREQ_1000K = PDM_PDMCLKCTRL_FREQ_1000K,  ///< PDM_CLK = 1.000 MHz.
      NRF_PDM_FREQ_1032K = PDM_PDMCLKCTRL_FREQ_Default,  ///< PDM_CLK = 1.032 MHz.
      NRF_PDM_FREQ_1067K = PDM_PDMCLKCTRL_FREQ_1067K   ///< PDM_CLK = 1.067 MHz.
  } nrf_pdm_freq_t;
  
  
  /**
   * @brief PDM operation mode.
   */
  typedef enum
  {
      NRF_PDM_MODE_STEREO = PDM_MODE_OPERATION_Stereo,  ///< Sample and store one pair (Left + Right) of 16-bit samples per RAM word.
      NRF_PDM_MODE_MONO   = PDM_MODE_OPERATION_Mono     ///< Sample and store two successive Left samples (16 bit each) per RAM word.
  } nrf_pdm_mode_t;
  
  
  /**
   * @brief PDM sampling mode.
   */
  typedef enum
  {
      NRF_PDM_EDGE_LEFTFALLING = PDM_MODE_EDGE_LeftFalling,  ///< Left (or mono) is sampled on falling edge of PDM_CLK.
      NRF_PDM_EDGE_LEFTRISING  = PDM_MODE_EDGE_LeftRising    ///< Left (or mono) is sampled on rising edge of PDM_CLK.
  } nrf_pdm_edge_t;
  
  
  /**
   * @brief Function for triggering a PDM task.
   *
   * @param[in] pdm_task PDM task.
   */
  __STATIC_INLINE void nrf_pdm_task_trigger(nrf_pdm_task_t pdm_task)
  {
      *((volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_task)) = 0x1UL;
  }
  
  
  /**
   * @brief Function for getting the address of a PDM task register.
   *
   * @param[in] pdm_task PDM task.
   *
   * @return Address of the specified PDM task.
   */
  __STATIC_INLINE uint32_t nrf_pdm_task_address_get(nrf_pdm_task_t pdm_task)
  {
      return (uint32_t)((uint8_t *)NRF_PDM + (uint32_t)pdm_task);
  }
  
  
  /**
   * @brief Function for getting the state of a PDM event.
   *
   * @param[in] pdm_event PDM event.
   *
   * @return State of the specified PDM event.
   */
  __STATIC_INLINE bool nrf_pdm_event_check(nrf_pdm_event_t pdm_event)
  {
      return (bool)*(volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event);
  }
  
  
  /**
   * @brief Function for clearing a PDM event.
   *
   * @param[in] pdm_event PDM event.
   */
  __STATIC_INLINE void nrf_pdm_event_clear(nrf_pdm_event_t pdm_event)
  {
      *((volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event)) = 0x0UL;
  #if __CORTEX_M == 0x04
      volatile uint32_t dummy = *((volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event));
      (void)dummy;
  #endif
  }
  
  
  /**
   * @brief Function for getting the address of a PDM event register.
   *
   * @param[in] pdm_event PDM event.
   *
   * @return Address of the specified PDM event.
   */
  __STATIC_INLINE volatile uint32_t * nrf_pdm_event_address_get(nrf_pdm_event_t pdm_event)
  {
      return (volatile uint32_t *)((uint8_t *)NRF_PDM + (uint32_t)pdm_event);
  }
  
  
  /**
   * @brief Function for enabling PDM interrupts.
   *
   * @param[in] pdm_int_mask Interrupts to enable.
   */
  __STATIC_INLINE void nrf_pdm_int_enable(uint32_t pdm_int_mask)
  {
      NRF_PDM->INTENSET = pdm_int_mask;
  }
  
  
  /**
   * @brief Function for retrieving the state of PDM interrupts.
   *
   * @param[in] pdm_int_mask Interrupts to check.
   *
   * @retval true  If all specified interrupts are enabled.
   * @retval false If at least one of the given interrupts is not enabled.
   */
  __STATIC_INLINE bool nrf_pdm_int_enable_check(uint32_t pdm_int_mask)
  {
      return (bool)(NRF_PDM->INTENSET & pdm_int_mask);
  }
  
  
  /**
   * @brief Function for disabling interrupts.
   *
   * @param pdm_int_mask Interrupts to disable.
   */
  __STATIC_INLINE void nrf_pdm_int_disable(uint32_t pdm_int_mask)
  {
      NRF_PDM->INTENCLR = pdm_int_mask;
  }
  
  
  /**
   * @brief Function for enabling the PDM peripheral.
   *
   * The PDM peripheral must be enabled before use.
   */
  __STATIC_INLINE void nrf_pdm_enable(void)
  {
      NRF_PDM->ENABLE = (PDM_ENABLE_ENABLE_Enabled << PDM_ENABLE_ENABLE_Pos);
  }
  
  
  /**
   * @brief Function for disabling the PDM peripheral.
   */
  __STATIC_INLINE void nrf_pdm_disable(void)
  {
      NRF_PDM->ENABLE = (PDM_ENABLE_ENABLE_Disabled << PDM_ENABLE_ENABLE_Pos);
  }
  
  
  /**
   * @brief Function for checking if the PDM peripheral is enabled.
   *
   * @retval true  If the PDM peripheral is enabled.
   * @retval false If the PDM peripheral is not enabled.
   */
  __STATIC_INLINE bool nrf_pdm_enable_check(void)
  {
      return (NRF_PDM->ENABLE == (PDM_ENABLE_ENABLE_Enabled << PDM_ENABLE_ENABLE_Pos));
  }
  
  
  /**
   * @brief Function for setting the PDM operation mode.
   *
   * @param[in] pdm_mode PDM operation mode.
   * @param[in] pdm_edge PDM sampling mode.
   */
  __STATIC_INLINE void nrf_pdm_mode_set(nrf_pdm_mode_t pdm_mode, nrf_pdm_edge_t pdm_edge)
  {
      NRF_PDM->MODE = ((pdm_mode << PDM_MODE_OPERATION_Pos) & PDM_MODE_OPERATION_Msk)
                      | ((pdm_edge << PDM_MODE_EDGE_Pos) & PDM_MODE_EDGE_Msk);
  }
  
  
  /**
   * @brief Function for getting the PDM operation mode.
   *
   * @param[out] p_pdm_mode PDM operation mode.
   * @param[out] p_pdm_edge PDM sampling mode.
   */
  __STATIC_INLINE void nrf_pdm_mode_get(nrf_pdm_mode_t * p_pdm_mode, nrf_pdm_edge_t * p_pdm_edge)
  {
      uint32_t mode = NRF_PDM->MODE;
      *p_pdm_mode = (nrf_pdm_mode_t)((mode & PDM_MODE_OPERATION_Msk ) >> PDM_MODE_OPERATION_Pos);
      *p_pdm_edge = (nrf_pdm_edge_t)((mode & PDM_MODE_EDGE_Msk ) >> PDM_MODE_EDGE_Pos);
  }
  
  
  /**
   * @brief Function for setting the PDM clock frequency.
   *
   * @param[in] pdm_freq PDM clock frequency.
   */
  __STATIC_INLINE void nrf_pdm_clock_set(nrf_pdm_freq_t pdm_freq)
  {
      NRF_PDM->PDMCLKCTRL = ((pdm_freq << PDM_PDMCLKCTRL_FREQ_Pos) & PDM_PDMCLKCTRL_FREQ_Msk);
  }
  
  
  /**
   * @brief Function for getting the PDM clock frequency.
   */
  __STATIC_INLINE nrf_pdm_freq_t nrf_pdm_clock_get(void)
  {
       return (nrf_pdm_freq_t) ((NRF_PDM->PDMCLKCTRL << PDM_PDMCLKCTRL_FREQ_Pos) & PDM_PDMCLKCTRL_FREQ_Msk);
  }
  
  
  /**
   * @brief Function for setting up the PDM pins.
   *
   * @param[in] psel_clk CLK pin number.
   * @param[in] psel_din DIN pin number.
   */
  __STATIC_INLINE void nrf_pdm_psel_connect(uint32_t psel_clk, uint32_t psel_din)
  {
      NRF_PDM->PSEL.CLK = psel_clk;
      NRF_PDM->PSEL.DIN = psel_din;
  }
  
  /**
   * @brief Function for disconnecting the PDM pins.
   */
  __STATIC_INLINE void nrf_pdm_psel_disconnect()
  {
      NRF_PDM->PSEL.CLK = ((PDM_PSEL_CLK_CONNECT_Disconnected << PDM_PSEL_CLK_CONNECT_Pos)
                           & PDM_PSEL_CLK_CONNECT_Msk);
      NRF_PDM->PSEL.DIN = ((PDM_PSEL_DIN_CONNECT_Disconnected << PDM_PSEL_DIN_CONNECT_Pos)
                           & PDM_PSEL_DIN_CONNECT_Msk);
  }
  
  
  /**
   * @brief Function for setting the PDM gain.
   *
   * @param[in] gain_l Left channel gain.
   * @param[in] gain_r Right channel gain.
   */
  __STATIC_INLINE void nrf_pdm_gain_set(nrf_pdm_gain_t gain_l, nrf_pdm_gain_t gain_r)
  {
      NRF_PDM->GAINL = gain_l;
      NRF_PDM->GAINR = gain_r;
  }
  
  
  /**
   * @brief Function for getting the PDM gain.
   *
   * @param[out] p_gain_l Left channel gain.
   * @param[out] p_gain_r Right channel gain.
   */
  __STATIC_INLINE void nrf_pdm_gain_get(nrf_pdm_gain_t * p_gain_l, nrf_pdm_gain_t * p_gain_r)
  {
      *p_gain_l = NRF_PDM->GAINL;
      *p_gain_r = NRF_PDM->GAINR;
  }
  
  
  /**
   * @brief Function for setting the PDM sample buffer.
   *
   * @param[in] p_buffer Pointer to the RAM address where samples should be written with EasyDMA.
   * @param[in] num    Number of samples to allocate memory for in EasyDMA mode.
   *
   * The amount of allocated RAM depends on the operation mode.
   * - For stereo mode: N 32-bit words.
   * - For mono mode: Ceil(N/2) 32-bit words.
   */
  __STATIC_INLINE void nrf_pdm_buffer_set(uint32_t * p_buffer, uint32_t num)
  {
      NRF_PDM->SAMPLE.PTR = (uint32_t)p_buffer;
      NRF_PDM->SAMPLE.MAXCNT = num;
  }
  
  /**
   * @brief Function for getting the current PDM sample buffer address.
   *
   * @return Pointer to the current sample buffer.
   */
  __STATIC_INLINE uint32_t * nrf_pdm_buffer_get()
  {
      return (uint32_t *)NRF_PDM->SAMPLE.PTR;
  }
  
  /** @} */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* NRF_PDM_H_ */
  