/*
 * Copyright (c) 2020, Texas Instruments Incorporated
 * All rights reserved.
 *
 * 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.
 */

/*
 *  ======== uart2echo.c ========
 */
#include <stdint.h>
#include <stddef.h>

/* Driver Header files */
#include <ti/drivers/GPIO.h>
#include <ti/drivers/UART2.h>
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>

/* Driver configuration */
#include "ti_drivers_config.h"

UART2_Handle uart;
UART2_Params uartParams;

void echo(uint32_t * excStack, uint32_t lr)
{
    char input;
    size_t bytesRead;
    size_t bytesWritten = 0;

    /* Loop forever echoing */
    while (1) {
        bytesRead = 0;
        while (bytesRead == 0) {
            UART2_read(uart, &input, 1, &bytesRead);
        }

        bytesWritten = 0;
        while (bytesWritten == 0) {
            UART2_write(uart, &input, 1, &bytesWritten);
        }


        // Trigger an exception if this is a task context
        if((input == 'e') && (BIOS_getThreadType() == BIOS_ThreadType_Task))
        {
            const char * exceptionMsg = "Triggering an exception!\r\n";
            UART2_write(uart, exceptionMsg, strlen(exceptionMsg), NULL);
            *((char *)NULL) = 5;
        }
    }
}

/*
 *  ======== mainThread ========
 */
void *mainThread(void *arg0)
{
    /* Call driver init functions */
    GPIO_init();

    /* Configure the LED pin */
    GPIO_setConfig(CONFIG_GPIO_LED_0, GPIO_CFG_OUT_STD | GPIO_CFG_OUT_LOW);

    /* Create a UART where the default read and write mode is BLOCKING */
    UART2_Params_init(&uartParams);
    uartParams.baudRate = 115200;
    uartParams.readMode = UART2_Mode_NONBLOCKING;
    uartParams.writeMode = UART2_Mode_NONBLOCKING;

    uart = UART2_open(CONFIG_UART2_0, &uartParams);

    if (uart == NULL) {
        /* UART2_open() failed */
        while (1);
    }

    /* Turn on user LED to indicate successful initialization */
    GPIO_write(CONFIG_GPIO_LED_0, CONFIG_GPIO_LED_ON);

    const char   echoPrompt[] = "Echoing characters:\r\n";
    UART2_write(uart, echoPrompt, sizeof(echoPrompt), NULL);

    echo(NULL, 0);
}