/** * Copyright (c) 2013 - 2020, 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 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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. * */ /**@file * * @defgroup app_fifo FIFO implementation * @{ * @ingroup app_common * * @brief FIFO implementation. */ #ifndef APP_FIFO_H__ #define APP_FIFO_H__ #include #include #ifdef __cplusplus extern "C" { #endif /**@brief A FIFO instance structure. * @details Keeps track of which bytes to read and write next. * Also, it keeps the information about which memory is allocated for the buffer * and its size. This structure must be initialized by app_fifo_init() before use. */ typedef struct { uint8_t * p_buf; /**< Pointer to FIFO buffer memory. */ uint16_t buf_size_mask; /**< Read/write index mask. Also used for size checking. */ volatile uint32_t read_pos; /**< Next read position in the FIFO buffer. */ volatile uint32_t write_pos; /**< Next write position in the FIFO buffer. */ } app_fifo_t; /**@brief Function for initializing the FIFO. * * @param[out] p_fifo FIFO object. * @param[in] p_buf FIFO buffer for storing data. The buffer size must be a power of two. * @param[in] buf_size Size of the FIFO buffer provided. This size must be a power of two. * * @retval NRF_SUCCESS If initialization was successful. * @retval NRF_ERROR_NULL If a NULL pointer is provided as buffer. * @retval NRF_ERROR_INVALID_LENGTH If size of buffer provided is not a power of two. */ uint32_t app_fifo_init(app_fifo_t * p_fifo, uint8_t * p_buf, uint16_t buf_size); /**@brief Function for adding an element to the FIFO. * * @param[in] p_fifo Pointer to the FIFO. * @param[in] byte Data byte to add to the FIFO. * * @retval NRF_SUCCESS If an element has been successfully added to the FIFO. * @retval NRF_ERROR_NO_MEM If the FIFO is full. */ uint32_t app_fifo_put(app_fifo_t * p_fifo, uint8_t byte); /**@brief Function for getting the next element from the FIFO. * * @param[in] p_fifo Pointer to the FIFO. * @param[out] p_byte Byte fetched from the FIFO. * * @retval NRF_SUCCESS If an element was returned. * @retval NRF_ERROR_NOT_FOUND If there are no more elements in the queue. */ uint32_t app_fifo_get(app_fifo_t * p_fifo, uint8_t * p_byte); /**@brief Function for looking at an element in the FIFO, without consuming it. * * @param[in] p_fifo Pointer to the FIFO. * @param[in] index Which element to look at. The lower the index, the earlier it was put. * @param[out] p_byte Byte fetched from the FIFO. * * @retval NRF_SUCCESS If an element was returned. * @retval NRF_ERROR_NOT_FOUND If there are no more elements in the queue, or the index was * too large. */ uint32_t app_fifo_peek(app_fifo_t * p_fifo, uint16_t index, uint8_t * p_byte); /**@brief Function for flushing the FIFO. * * @param[in] p_fifo Pointer to the FIFO. * * @retval NRF_SUCCESS If the FIFO was flushed successfully. */ uint32_t app_fifo_flush(app_fifo_t * p_fifo); /**@brief Function for reading bytes from the FIFO. * * This function can also be used to get the number of bytes in the FIFO. * * @param[in] p_fifo Pointer to the FIFO. Must not be NULL. * @param[out] p_byte_array Memory pointer where the read bytes are fetched from the FIFO. * Can be NULL. If NULL, the number of bytes that can be read in the FIFO * are returned in the p_size parameter. * @param[inout] p_size Address to memory indicating the maximum number of bytes to be read. * The provided memory is overwritten with the actual number of bytes * read if the procedure was successful. This field must not be NULL. * If p_byte_array is set to NULL by the application, this parameter * returns the number of bytes in the FIFO. * * @retval NRF_SUCCESS If the procedure is successful. The actual number of bytes read might * be less than the requested maximum, depending on how many elements exist * in the FIFO. Even if less bytes are returned, the procedure is considered * successful. * @retval NRF_ERROR_NULL If a NULL parameter was passed for a parameter that must not * be NULL. * @retval NRF_ERROR_NOT_FOUND If the FIFO is empty. */ uint32_t app_fifo_read(app_fifo_t * p_fifo, uint8_t * p_byte_array, uint32_t * p_size); /**@brief Function for writing bytes to the FIFO. * * This function can also be used to get the available size on the FIFO. * * @param[in] p_fifo Pointer to the FIFO. Must not be NULL. * @param[in] p_byte_array Memory pointer containing the bytes to be written to the FIFO. * Can be NULL. If NULL, this function returns the number of bytes * that can be written to the FIFO. * @param[inout] p_size Address to memory indicating the maximum number of bytes to be written. * The provided memory is overwritten with the number of bytes that were actually * written if the procedure is successful. This field must not be NULL. * If p_byte_array is set to NULL by the application, this parameter * returns the number of bytes available in the FIFO. * * @retval NRF_SUCCESS If the procedure is successful. The actual number of bytes written might * be less than the requested maximum, depending on how much room there is in * the FIFO. Even if less bytes are written, the procedure is considered * successful. If the write was partial, the application should use * subsequent calls to attempt writing the data again. * @retval NRF_ERROR_NULL If a NULL parameter was passed for a parameter that must not * be NULL. * @retval NRF_ERROR_NO_MEM If the FIFO is full. * */ uint32_t app_fifo_write(app_fifo_t * p_fifo, uint8_t const * p_byte_array, uint32_t * p_size); #ifdef __cplusplus } #endif #endif // APP_FIFO_H__ /** @} */