uart_async_rx.h

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/*
 * Copyright (c) 2023 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_DRIVERS_SERIAL_UART_ASYNC_RX_H_
#define ZEPHYR_DRIVERS_SERIAL_UART_ASYNC_RX_H_
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <zephyr/kernel.h>
 
/* @brief RX buffer structure which holds the buffer and its state. */
struct uart_async_rx_buf {
        /* Write index which is incremented whenever new data is reported to be
         * received to that buffer.
         */
        uint8_t wr_idx:7;
 
        /* Set to one if buffer is released by the driver. */
        uint8_t completed:1;
 
        /* Location which is passed to the UART driver. */
        uint8_t buffer[];
};
 
struct uart_async_rx {
        /* Pointer to the configuration structure. Structure must be persistent. */
        const struct uart_async_rx_config *config;
 
        /* Total amount of pending bytes. Bytes may be spread across multiple RX buffers. */
        atomic_t pending_bytes;
 
        /* Number of buffers which are free. */
        atomic_t free_buf_cnt;
 
        /* Single buffer size. */
        uint8_t buf_len;
 
        /* Index of the next buffer to be provided to the driver. */
        uint8_t drv_buf_idx;
 
        /* Current buffer from which data is being consumed. */
        uint8_t rd_buf_idx;
 
        /* Current read index in the buffer from which data is being consumed.
         * Read index which is incremented whenever data is consumed from the buffer.
         */
        uint8_t rd_idx;
};
 
struct uart_async_rx_config {
        /* Pointer to the buffer. */
        uint8_t *buffer;
 
        /* Buffer length. */
        size_t length;
 
        /* Number of buffers into provided space shall be split. */
        uint8_t buf_cnt;
};
 
static inline uint8_t uart_async_rx_get_buf_len(struct uart_async_rx *async_rx)
{
        return async_rx->buf_len;
}
 
#define UART_ASYNC_RX_BUF_OVERHEAD offsetof(struct uart_async_rx_buf, buffer)
 
int uart_async_rx_init(struct uart_async_rx *async_rx,
                       const struct uart_async_rx_config *config);
 
void uart_async_rx_reset(struct uart_async_rx *async_rx);
 
void uart_async_rx_on_rdy(struct uart_async_rx *async_rx, uint8_t *buffer, size_t length);
 
uint8_t *uart_async_rx_buf_req(struct uart_async_rx *async_rx);
 
void uart_async_rx_on_buf_rel(struct uart_async_rx *async_rx, uint8_t *buf);
 
size_t uart_async_rx_data_claim(struct uart_async_rx *async_rx, uint8_t **data, size_t length);
 
bool uart_async_rx_data_consume(struct uart_async_rx *async_rx, size_t length);
 
#ifdef __cplusplus
}
#endif
 
#endif /* ZEPHYR_DRIVERS_SERIAL_UART_ASYNC_RX_H_ */