/**
* Copyright (c) 2015 - 2017, 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
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*/
/**
* @addtogroup nrf_pdm PDM HAL and driver
* @ingroup nrf_drivers
* @brief @tagAPI52 Pulse density modulation (PDM) interface APIs.
*
* The PDM HAL provides basic APIs for accessing the registers of the PDM interface peripheral.
* The PDM driver provides APIs on a higher level.
*
* @defgroup nrf_drv_pdm PDM driver
* @{
* @ingroup nrf_pdm
*
* @brief @tagAPI52 Pulse density modulation (PDM) interface driver.
*/
#ifndef NRF_DRV_PDM_H__
#define NRF_DRV_PDM_H__
#include "sdk_config.h"
#include "nrf_pdm.h"
#include "sdk_errors.h"
#ifdef __cplusplus
extern "C" {
#endif
#define NRF_PDM_MAX_BUFFER_SIZE 32768
/**
* @brief PDM interface driver configuration structure.
*/
typedef struct
{
nrf_pdm_mode_t mode; ///< Interface operation mode.
nrf_pdm_edge_t edge; ///< Sampling mode.
uint8_t pin_clk; ///< CLK pin.
uint8_t pin_din; ///< DIN pin.
nrf_pdm_freq_t clock_freq; ///< Clock frequency.
nrf_pdm_gain_t gain_l; ///< Left channel gain.
nrf_pdm_gain_t gain_r; ///< Right channel gain.
uint8_t interrupt_priority; ///< Interrupt priority.
uint16_t buffer_length; ///< Length of a single buffer (in 16-bit words).
int16_t * buffer_a; ///< Sample buffer A (filled first).
int16_t * buffer_b; ///< Sample buffer B (filled after buffer A).
} nrf_drv_pdm_config_t;
/**
* @brief Macro for setting @ref nrf_drv_pdm_config_t to default settings
* in single ended mode.
*
* @param PIN_CLK CLK output pin.
* @param PIN_DIN DIN input pin.
* @param BUFF_A Sample buffer A (filled first).
* @param BUFF_B Sample buffer B (filled after buffer A).
* @param BUFF_LEN Length of a single buffer (in 16-bit words).
*/
#define NRF_DRV_PDM_DEFAULT_CONFIG(PIN_CLK, PIN_DIN, BUFF_A, BUFF_B, BUFF_LEN) \
{ \
.mode = (nrf_pdm_mode_t)PDM_CONFIG_MODE, \
.edge = (nrf_pdm_edge_t)PDM_CONFIG_EDGE, \
.pin_clk = PIN_CLK, \
.pin_din = PIN_DIN, \
.clock_freq = (nrf_pdm_freq_t)PDM_CONFIG_CLOCK_FREQ, \
.gain_l = NRF_PDM_GAIN_DEFAULT, \
.gain_r = NRF_PDM_GAIN_DEFAULT, \
.interrupt_priority = PDM_CONFIG_IRQ_PRIORITY, \
.buffer_length = BUFF_LEN, \
.buffer_a = BUFF_A, \
.buffer_b = BUFF_B \
}
/**
* @brief Handler for PDM interface ready events.
*
* This event handler is called when a buffer is full and ready to be processed.
*
* @param[in] p_buffer Sample buffer pointer.
* @param[in] length Buffer length in 16-bit words.
*/
typedef void (*nrf_drv_pdm_event_handler_t)(uint32_t * buffer, uint16_t length);
/**
* @brief Function for initializing the PDM interface.
*
* @param[in] p_config Pointer to a configuration structure. If NULL, the default one is used.
* @param[in] event_handler Event handler provided by the user.
*
* @retval NRF_SUCCESS If initialization was successful.
* @retval NRF_ERROR_INVALID_STATE If the driver is already initialized.
* @retval NRF_ERROR_INVALID_PARAM If invalid parameters were specified.
*/
ret_code_t nrf_drv_pdm_init(nrf_drv_pdm_config_t const * p_config,
nrf_drv_pdm_event_handler_t event_handler);
/**
* @brief Function for uninitializing the PDM interface.
*
* This function stops PDM sampling, if it is in progress.
*/
void nrf_drv_pdm_uninit(void);
/**
* @brief Function for getting the address of a PDM interface task.
*
* @param[in] task Task.
*
* @return Task address.
*/
__STATIC_INLINE uint32_t nrf_drv_pdm_task_address_get(nrf_pdm_task_t task)
{
return nrf_pdm_task_address_get(task);
}
/**
* @brief Function for getting the state of the PDM interface.
*
* @retval TRUE If the PDM interface is enabled.
* @retval FALSE If the PDM interface is disabled.
*/
__STATIC_INLINE bool nrf_drv_pdm_enable_check()
{
return nrf_pdm_enable_check();
}
/**
* @brief Function for starting PDM sampling.
*
* @retval NRF_SUCCESS If sampling was started successfully or was already in progress.
* @retval NRF_ERROR_BUSY If a previous start/stop operation is in progress.
*/
ret_code_t nrf_drv_pdm_start(void);
/**
* @brief Function for stopping PDM sampling.
*
* When this function is called, the PDM interface is stopped after finishing
* the current frame.
* The event handler function might be called once more after calling this function.
*
* @retval NRF_SUCCESS If sampling was stopped successfully or was already stopped before.
* @retval NRF_ERROR_BUSY If a previous start/stop operation is in progress.
*/
ret_code_t nrf_drv_pdm_stop(void);
#ifdef __cplusplus
}
#endif
#endif // NRF_DRV_PDM_H__
/** @} */