boards/evkmimx8mq/driver_examples/uart/interrupt_transfer/uart_interrupt_transfer.c

/*
 * Copyright (c) 2015, Freescale Semiconductor, Inc.
 * Copyright 2016-2017 NXP
 * All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "board.h"
#include "fsl_uart.h"

#include "pin_mux.h"
#include "clock_config.h"
/*******************************************************************************
 * Definitions
 ******************************************************************************/
#define DEMO_UART          UART2
#define DEMO_UART_CLK_FREQ BOARD_DEBUG_UART_CLK_FREQ

#define ECHO_BUFFER_LENGTH 8

/*******************************************************************************
 * Prototypes
 ******************************************************************************/

/* UART user callback */
void UART_UserCallback(UART_Type *base, uart_handle_t *handle, status_t status, void *userData);

/*******************************************************************************
 * Variables
 ******************************************************************************/
uart_handle_t g_uartHandle;

uint8_t g_tipString[] =
    "Uart interrupt transfer example\r\nBoard receives 8 characters then sends them out\r\nNow please input:\r\n";

uint8_t g_txBuffer[ECHO_BUFFER_LENGTH] = {0};
uint8_t g_rxBuffer[ECHO_BUFFER_LENGTH] = {0};
volatile bool rxBufferEmpty            = true;
volatile bool txBufferFull             = false;
volatile bool txOnGoing                = false;
volatile bool rxOnGoing                = false;

/*******************************************************************************
 * Code
 ******************************************************************************/
/* UART user callback */
void UART_UserCallback(UART_Type *base, uart_handle_t *handle, status_t status, void *userData)
{
    userData = userData;

    if (kStatus_UART_TxIdle == status)
    {
        txBufferFull = false;
        txOnGoing    = false;
    }

    if (kStatus_UART_RxIdle == status)
    {
        rxBufferEmpty = false;
        rxOnGoing     = false;
    }
}

/*!
 * @brief Main function
 */
int main(void)
{
    status_t status;
    uart_config_t config;
    uart_transfer_t xfer;
    uart_transfer_t sendXfer;
    uart_transfer_t receiveXfer;

    /* Board specific RDC settings */
    BOARD_RdcInit();

    BOARD_InitPins();
    BOARD_BootClockRUN();
    BOARD_InitMemory();
    /*
     * config.baudRate_Bps = 115200U;
     * config.parityMode = kUART_ParityDisabled;
     * config.dataBitsCount = kUART_EightDataBits;
     * config.stopBitCount = kUART_OneStopBit;
     * config.txFifoWatermark = 2;
     * config.rxFifoWatermark = 16;
     * config.enableTx = false;
     * config.enableRx = false;
     */
    UART_GetDefaultConfig(&config);
    config.baudRate_Bps    = BOARD_DEBUG_UART_BAUDRATE;
    config.rxFifoWatermark = 16;
    config.enableTx        = true;
    config.enableRx        = true;

    status = UART_Init(DEMO_UART, &config, DEMO_UART_CLK_FREQ);
    if (kStatus_Success != status)
    {
        return kStatus_Fail;
    }

    UART_TransferCreateHandle(DEMO_UART, &g_uartHandle, UART_UserCallback, NULL);

    /* Send g_tipString out. */
    xfer.data     = g_tipString;
    xfer.dataSize = sizeof(g_tipString) - 1;
    txOnGoing     = true;
    UART_TransferSendNonBlocking(DEMO_UART, &g_uartHandle, &xfer);

    /* Wait send finished */
    while (txOnGoing)
    {
    }

    /* Start to echo. */
    sendXfer.data        = g_txBuffer;
    sendXfer.dataSize    = ECHO_BUFFER_LENGTH;
    receiveXfer.data     = g_rxBuffer;
    receiveXfer.dataSize = ECHO_BUFFER_LENGTH;

    while (1)
    {
        /* If RX is idle and g_rxBuffer is empty, start to read data to g_rxBuffer. */
        if ((!rxOnGoing) && rxBufferEmpty)
        {
            rxOnGoing = true;
            UART_TransferReceiveNonBlocking(DEMO_UART, &g_uartHandle, &receiveXfer, NULL);
        }

        /* If TX is idle and g_txBuffer is full, start to send data. */
        if ((!txOnGoing) && txBufferFull)
        {
            txOnGoing = true;
            UART_TransferSendNonBlocking(DEMO_UART, &g_uartHandle, &sendXfer);
        }

        /* If g_txBuffer is empty and g_rxBuffer is full, copy g_rxBuffer to g_txBuffer. */
        if ((!rxBufferEmpty) && (!txBufferFull))
        {
            memcpy(g_txBuffer, g_rxBuffer, ECHO_BUFFER_LENGTH);
            rxBufferEmpty = true;
            txBufferFull  = true;
        }
    }
}