owner-nrf52sdk/nRF5_SDK_15.2.0/modules/nrfx/drivers/include/nrfx_i2s.h

/**
 * Copyright (c) 2015 - 2018, Nordic Semiconductor ASA
 *
 * All rights reserved.
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 * are permitted provided that the following conditions are met:
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 *    software without specific prior written permission.
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 * 4. This software, with or without modification, must only be used with a
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#ifndef NRFX_I2S_H__
#define NRFX_I2S_H__

#include <nrfx.h>
#include <hal/nrf_i2s.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup nrfx_i2s I2S driver
 * @{
 * @ingroup nrf_i2s
 * @brief   Inter-IC Sound (I2S) peripheral driver.
 */


/**
 * @brief This value can be provided instead of a pin number for the signals
 *        SDOUT, SDIN, and MCK to specify that a given signal is not used
 *        and therefore does not need to be connected to a pin.
 */
#define NRFX_I2S_PIN_NOT_USED  0xFF

/** @brief I2S driver configuration structure. */
typedef struct
{
    uint8_t sck_pin;      ///< SCK pin number.
    uint8_t lrck_pin;     ///< LRCK pin number.
    uint8_t mck_pin;      ///< MCK pin number.
                          /**< Optional. Use @ref NRFX_I2S_PIN_NOT_USED
                           *   if this signal is not needed. */
    uint8_t sdout_pin;    ///< SDOUT pin number.
                          /**< Optional. Use @ref NRFX_I2S_PIN_NOT_USED
                           *   if this signal is not needed. */
    uint8_t sdin_pin;     ///< SDIN pin number.
                          /**< Optional. Use @ref NRFX_I2S_PIN_NOT_USED
                           *   if this signal is not needed. */
    uint8_t irq_priority; ///< Interrupt priority.

    nrf_i2s_mode_t     mode;         ///< Mode of operation.
    nrf_i2s_format_t   format;       ///< Frame format.
    nrf_i2s_align_t    alignment;    ///< Alignment of sample within a frame.
    nrf_i2s_swidth_t   sample_width; ///< Sample width.
    nrf_i2s_channels_t channels;     ///< Enabled channels.
    nrf_i2s_mck_t      mck_setup;    ///< Master clock setup.
    nrf_i2s_ratio_t    ratio;        ///< MCK/LRCK ratio.
} nrfx_i2s_config_t;

/** @brief I2S driver buffers structure. */
typedef struct
{
    uint32_t       * p_rx_buffer;
    uint32_t const * p_tx_buffer;
} nrfx_i2s_buffers_t;

/**
 * @brief I2S driver default configuration.
 */
#define NRFX_I2S_DEFAULT_CONFIG                                   \
{                                                                 \
    .sck_pin      = NRFX_I2S_CONFIG_SCK_PIN,                      \
    .lrck_pin     = NRFX_I2S_CONFIG_LRCK_PIN,                     \
    .mck_pin      = NRFX_I2S_CONFIG_MCK_PIN,                      \
    .sdout_pin    = NRFX_I2S_CONFIG_SDOUT_PIN,                    \
    .sdin_pin     = NRFX_I2S_CONFIG_SDIN_PIN,                     \
    .irq_priority = NRFX_I2S_CONFIG_IRQ_PRIORITY,                 \
    .mode         = (nrf_i2s_mode_t)NRFX_I2S_CONFIG_MASTER,       \
    .format       = (nrf_i2s_format_t)NRFX_I2S_CONFIG_FORMAT,     \
    .alignment    = (nrf_i2s_align_t)NRFX_I2S_CONFIG_ALIGN,       \
    .sample_width = (nrf_i2s_swidth_t)NRFX_I2S_CONFIG_SWIDTH,     \
    .channels     = (nrf_i2s_channels_t)NRFX_I2S_CONFIG_CHANNELS, \
    .mck_setup    = (nrf_i2s_mck_t)NRFX_I2S_CONFIG_MCK_SETUP,     \
    .ratio        = (nrf_i2s_ratio_t)NRFX_I2S_CONFIG_RATIO,       \
}


#define NRFX_I2S_STATUS_NEXT_BUFFERS_NEEDED  (1UL << 0)
    /**< The application should provide buffers that are to be used in the next
     *   part of the transfer. A call to @ref nrfx_i2s_next_buffers_set should
     *   be done before the currently used buffers are completely processed
     *   (i.e. the time remaining for supplying the next buffers depends on
     *   the used size of the buffers). */

/**
 * @brief I2S driver data handler type.
 *
 * A data handling function of this type must be specified during initialization
 * of the driver. The driver will call this function when it finishes using
 * buffers passed to it by the application, and when it needs to be provided
 * with buffers for the next part of the transfer.
 *
 * @note The @c p_released pointer passed to this function is temporary and
 *       will be invalid after the function returns, hence it cannot be stored
 *       and used later. If needed, the pointed content (i.e. buffers pointers)
 *       should be copied instead.
 *
 * @param[in] p_released  Pointer to a structure with pointers to buffers
 *                        passed previously to the driver that will no longer
 *                        be access by it (they can be now safely released or
 *                        used for another purpose, in particular for a next
 *                        part of the transfer).
 *                        This pointer will be NULL if the application did not
 *                        supply the buffers for the next part of the transfer
 *                        (via a call to @ref nrfx_i2s_next_buffers_set) since
 *                        the previous time the data handler signaled such need.
 *                        This means that data corruption occurred (the previous
 *                        buffers are used for the second time) and no buffers
 *                        can be released at the moment.
 *                        Both pointers in this structure are NULL when the
 *                        handler is called for the first time after a transfer
 *                        is started, because no data has been transferred yet
 *                        at this point. In all successive calls the pointers
 *                        specify what has been sent (TX) and what has been
 *                        received (RX) in the part of transfer that has just
 *                        been completed (provided that a given direction is
 *                        enabled, see @ref nrfx_i2s_start).
 * @param[in] status  Bit field describing the current status of the transfer.
 *                    It can be 0 or a combination of the following flags:
 *                    - @ref NRFX_I2S_STATUS_NEXT_BUFFERS_NEEDED
 */
typedef void (* nrfx_i2s_data_handler_t)(nrfx_i2s_buffers_t const * p_released,
                                         uint32_t                   status);


/**
 * @brief Function for initializing the I2S driver.
 *
 * @param[in] p_config  Pointer to the structure with initial configuration.
 * @param[in] handler   Data handler provided by the user. Must not be NULL.
 *
 * @retval NRFX_SUCCESS              If initialization was successful.
 * @retval NRFX_ERROR_INVALID_STATE  If the driver was already initialized.
 * @retval NRFX_ERROR_INVALID_PARAM  If the requested combination of configuration
 *                                   options is not allowed by the I2S peripheral.
 */
nrfx_err_t nrfx_i2s_init(nrfx_i2s_config_t const * p_config,
                         nrfx_i2s_data_handler_t   handler);

/** @brief Function for uninitializing the I2S driver. */
void nrfx_i2s_uninit(void);

/**
 * @brief Function for starting the continuous I2S transfer.
 *
 * The I2S data transfer can be performed in one of three modes: RX (reception)
 * only, TX (transmission) only, or in both directions simultaneously.
 * The mode is selected by specifying a proper buffer for a given direction
 * in the call to this function or by passing NULL instead if this direction
 * should be disabled.
 *
 * The length of the buffer (which is a common value for RX and TX if both
 * directions are enabled) is specified in 32-bit words. One 32-bit memory
 * word can either contain four 8-bit samples, two 16-bit samples, or one
 * right-aligned 24-bit sample sign-extended to a 32-bit value.
 * For a detailed memory mapping for different supported configurations,
 * see the @linkProductSpecification52.
 *
 * @note Peripherals using EasyDMA (including I2S) require the transfer buffers
 *       to be placed in the Data RAM region. If this condition is not met,
 *       this function will fail with the error code NRFX_ERROR_INVALID_ADDR.
 *
 * @param[in] p_initial_buffers  Pointer to a structure specifying the buffers
 *                               to be used in the initial part of the transfer
 *                               (buffers for all consecutive parts are provided
 *                               through the data handler).
 * @param[in] buffer_size        Size of the buffers (in 32-bit words).
 *                               Must not be 0.
 * @param[in] flags              Transfer options (0 for default settings).
 *                               Currently, no additional flags are available.
 *
 * @retval NRFX_SUCCESS              If the operation was successful.
 * @retval NRFX_ERROR_INVALID_STATE  If a transfer was already started or
 *                                   the driver has not been initialized.
 * @retval NRFX_ERROR_INVALID_ADDR   If the provided buffers are not placed
 *                                   in the Data RAM region.
 */
nrfx_err_t nrfx_i2s_start(nrfx_i2s_buffers_t const * p_initial_buffers,
                          uint16_t                   buffer_size,
                          uint8_t                    flags);

/**
 * @brief Function for supplying the buffers to be used in the next part of
 *        the transfer.
 *
 * The application should call this function when the data handler receives
 * @ref NRFX_I2S_STATUS_NEXT_BUFFERS_NEEDED in the @c status parameter.
 * The call can be done immediately from the data handler function or later,
 * but it has to be done before the I2S peripheral finishes processing the
 * buffers supplied previously. Otherwise, data corruption will occur.
 *
 * @sa nrfx_i2s_data_handler_t
 *
 * @retval NRFX_SUCCESS              If the operation was successful.
 * @retval NRFX_ERROR_INVALID_STATE  If the buffers were already supplied or
 *                                   the peripheral is currently being stopped.
 */
nrfx_err_t nrfx_i2s_next_buffers_set(nrfx_i2s_buffers_t const * p_buffers);

/** @brief Function for stopping the I2S transfer. */
void nrfx_i2s_stop(void);

/** @} */


void nrfx_i2s_irq_handler(void);


#ifdef __cplusplus
}
#endif

#endif // NRFX_I2S_H__