Demonstration how to use UART with SYS/BIOS.

sys_bios_uart_example.c

/*
 * uartSample_main.c
 *
 * This file contains the test / demo code to demonstrate the UART driver
 * functionality on SYS/BIOS 6
 *
 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
 *
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *    Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 *    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.
 *
 *    Neither the name of Texas Instruments Incorporated 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
 *  OWNER 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    uartSample_main.c
 *
 * \brief   This file contains the test / demo code to demonstrate the
 *          UART driver implemented for SYS/BIOS 6
 *
 *          (C) Copyright 2009, Texas Instruments, Inc
 *
 * \author  PSG
 *
 * \version 0.1   created for the OMAPL138 and C6748 platforms
 */

/* ========================================================================== */
/*                              INCLUDE FILES                                 */
/* ========================================================================== */

#include <xdc/std.h>
#include <string.h>
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/io/GIO.h>
#include <xdc/runtime/log.h>
#include <ti/sysbios/knl/Task.h>
#include <ti/sysbios/knl/Clock.h>
#include <xdc/runtime/Error.h>
#include <xdc/runtime/System.h>
#include <ti/sdo/edma3/drv/edma3_drv.h>

#include <psc/include/Psc.h>
#include <uart/include/Uart.h>
#include <uart/include/UartLocal.h>
#include <platforms/evm6748/Uart_evmInit.h>


GIO_Handle uartRxHandle;
GIO_Handle uartTxHandle;

Task_Handle TASK_uart;
Clock_Handle CLOCK_uart_out;

#define SIZEOF_UART_START_STRING   100
#pragma DATA_ALIGN(uartTestStringStart, 128);
static char uartTestStringStart[SIZEOF_UART_START_STRING];

Semaphore_Handle SEM_uart_tx;
EDMA3_DRV_Handle hEdma;
GIO_Handle uartRxHandle;
GIO_Handle uartTxHandle;
Uart_Params   uartParams;
EDMA3_DRV_Handle edma3init(unsigned int edma3Id, EDMA3_DRV_Result *);

static Void uartEdmaInit(Void);
void user_uart_init(void);
static void uart_out_fired(UArg arg0);
void uartSampleTask(UArg arg1, UArg arg2);


void main(Void)
{
    System_printf("\r\nUart Sample Main\n");

    /* Call the EVM specific initialization function                          */
    configureUart();

    TASK_uart = Task_create(uartSampleTask, NULL, NULL);

    SEM_uart_tx = Semaphore_create(0, NULL, NULL);

    Clock_Params clkParams;
    Clock_Params_init(&clkParams);
    clkParams.startFlag = TRUE;
    clkParams.period = 1000;
    CLOCK_uart_out = Clock_create(uart_out_fired, 1000, &clkParams, NULL);

    BIOS_start();

    return;
}


static void uart_out_fired(UArg arg0) {
	Semaphore_post(SEM_uart_tx);
}

void uartSampleTask(UArg arg1, UArg arg2)
{
    Uart_ChanParams    	chanParams;
	Error_Block 		eb;
 	GIO_Params 			ioParams;

    Error_init(&eb);

    /*
     * Initialize channel attributes.
     */
    GIO_Params_init(&ioParams);
    /* initialise the edma library and get the EDMA handle                    */
    uartEdmaInit();

    /* update the edma Handle                                                 */
    chanParams.hEdma = hEdma;
    ioParams.chanParams = (Ptr)&chanParams;

   	/* create the required streams for the UART demo                           */
    uartTxHandle = GIO_create("/uart2", GIO_OUTPUT, &ioParams, &eb);
    uartRxHandle = GIO_create("/uart2",GIO_INPUT, &ioParams, &eb);

    if ((NULL == uartRxHandle) || (NULL == uartTxHandle))
    {
        System_printf("\nStream creation failed\n");
    }
    else
    {
    	size_t    len     =  0;
		char     *string  =  NULL;
		Int		  status  =  IOM_COMPLETED;

		string = "UART looping demo is started\n";

		strcpy(uartTestStringStart,string);
		len = strlen(uartTestStringStart);

    	while (1)
    	{
    		Semaphore_pend(SEM_uart_tx, BIOS_WAIT_FOREVER);

    	    status = GIO_write(uartTxHandle,&uartTestStringStart,&len);
    	    if (IOM_COMPLETED != status)
    	    {
    		 	System_printf("\r\nGIO_write failed. returned : %d", status);
    	    }

    	    // instaead of clock and semaphore we can also sleep here
    	    // but for demo purposes lets use also clock and semaphore
    	    //Task_sleep(1000);
    	}
    }
}


static void uartEdmaInit(Void)
{
    EDMA3_DRV_Result    edmaResult      = 0;

    hEdma = edma3init(0, &edmaResult);

    if (edmaResult != EDMA3_DRV_SOK)
    {
        /* Report EDMA Error */
        System_printf("\nEDMA driver initialization FAIL\n");
    }
    else
    {
        System_printf("\nEDMA driver initialization PASS.\n");
    }
}

/*
 * UART2 init function called when creating the driver.
 */
void user_uart_init()
{
    Uart_init();

    uartParams = Uart_PARAMS;
	uartParams.opMode = Uart_OpMode_DMAINTERRUPT;
	uartParams.baudRate = Uart_BaudRate_115_2K;
	uartParams.hwiNumber = 9;
	uartParams.rxThreshold = Uart_RxTrigLvl_1;
	uartParams.softTxFifoThreshold = 1;

	if(Uart_OpMode_POLLED == uartParams.opMode)
	{
		System_printf("\r\nUart is configured in polled mode");
	}
	else if (Uart_OpMode_INTERRUPT == uartParams.opMode)
	{
		System_printf("\r\nUart is configured in interrupt mode");
	}
	else if (Uart_OpMode_DMAINTERRUPT == uartParams.opMode)
	{
		System_printf("\r\nUart is configured in dma mode");
	}
	else
	{
		System_printf("\r\nError: Unknown mode of operation!!!!!!!!!!");
	}
}