/* * 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 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 the copyright holder nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * 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 NRFX_PDM_H__ #define NRFX_PDM_H__ #include #include #ifdef __cplusplus extern "C" { #endif /** * @defgroup nrfx_pdm PDM driver * @{ * @ingroup nrf_pdm * @brief Pulse Density Modulation (PDM) peripheral driver. */ #define NRFX_PDM_MAX_BUFFER_SIZE 32767 /** * @brief PDM error type. */ typedef enum { NRFX_PDM_NO_ERROR = 0, NRFX_PDM_ERROR_OVERFLOW = 1 } nrfx_pdm_error_t; /** * @brief PDM event structure. */ typedef struct { bool buffer_requested; ///< Buffer request flag. int16_t * buffer_released; ///< Pointer to the released buffer. Can be NULL. nrfx_pdm_error_t error; ///< Error type. } nrfx_pdm_evt_t; /** * @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. } nrfx_pdm_config_t; /** * @brief Macro for setting @ref nrfx_pdm_config_t to default settings * in single ended mode. * * @param _pin_clk CLK output pin. * @param _pin_din DIN input pin. */ #define NRFX_PDM_DEFAULT_CONFIG(_pin_clk, _pin_din) \ { \ .mode = (nrf_pdm_mode_t)NRFX_PDM_CONFIG_MODE, \ .edge = (nrf_pdm_edge_t)NRFX_PDM_CONFIG_EDGE, \ .pin_clk = _pin_clk, \ .pin_din = _pin_din, \ .clock_freq = (nrf_pdm_freq_t)NRFX_PDM_CONFIG_CLOCK_FREQ, \ .gain_l = NRF_PDM_GAIN_DEFAULT, \ .gain_r = NRF_PDM_GAIN_DEFAULT, \ .interrupt_priority = NRFX_PDM_CONFIG_IRQ_PRIORITY \ } /** * @brief Handler for PDM interface ready events. * * This event handler is called on a buffer request, an error or when a buffer * is full and ready to be processed. * * @param[in] p_evt Pointer to the PDM event structure. */ typedef void (*nrfx_pdm_event_handler_t)(nrfx_pdm_evt_t const * const p_evt); /** * @brief Function for initializing the PDM interface. * * @param[in] p_config Pointer to the structure with initial configuration. * @param[in] event_handler Event handler provided by the user. Cannot be NULL. * * @retval NRFX_SUCCESS If initialization was successful. * @retval NRFX_ERROR_INVALID_STATE If the driver is already initialized. * @retval NRFX_ERROR_INVALID_PARAM If invalid configuration was specified. */ nrfx_err_t nrfx_pdm_init(nrfx_pdm_config_t const * p_config, nrfx_pdm_event_handler_t event_handler); /** * @brief Function for uninitializing the PDM interface. * * This function stops PDM sampling, if it is in progress. */ void nrfx_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 nrfx_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 nrfx_pdm_enable_check(void) { return nrf_pdm_enable_check(); } /** * @brief Function for starting PDM sampling. * * @retval NRFX_SUCCESS If sampling was started successfully or was already in progress. * @retval NRFX_ERROR_BUSY If a previous start/stop operation is in progress. */ nrfx_err_t nrfx_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 NRFX_SUCCESS If sampling was stopped successfully or was already stopped before. * @retval NRFX_ERROR_BUSY If a previous start/stop operation is in progress. */ nrfx_err_t nrfx_pdm_stop(void); /** * @brief Function for supplying the sample buffer. * * Call this function after every buffer request event. * * @param[in] buffer Pointer to the receive buffer. Cannot be NULL. * @param[in] buffer_length Length of the receive buffer in 16-bit words. * * @retval NRFX_SUCCESS If the buffer was applied successfully. * @retval NRFX_ERROR_BUSY If the buffer was already supplied or the peripheral is currently being stopped. * @retval NRFX_ERROR_INVALID_STATE If the driver was not initialized. * @retval NRFX_ERROR_INVALID_PARAM If invalid parameters were provided. */ nrfx_err_t nrfx_pdm_buffer_set(int16_t * buffer, uint16_t buffer_length); void nrfx_pdm_irq_handler(void); /** @} */ #ifdef __cplusplus } #endif #endif // NRFX_PDM_H__