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/*

    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

    ***************************************************************************

    *                                                                         *

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    *                                                                         *

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    ***************************************************************************

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under

    the terms of the GNU General Public License (version 2) as published by the

    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.

    ***NOTE*** The exception to the GPL is included to allow you to distribute

    a combined work that includes FreeRTOS without being obliged to provide the

    source code for proprietary components outside of the FreeRTOS kernel.

    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT

    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

    more details. You should have received a copy of the GNU General Public

    License and the FreeRTOS license exception along with FreeRTOS; if not it

    can be viewed here: http://www.freertos.org/a00114.html and also obtained

    by writing to Richard Barry, contact details for whom are available on the

    FreeRTOS WEB site.

    1 tab == 4 spaces!

    http://www.FreeRTOS.org - Documentation, latest information, license and

    contact details.

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*/

/*

 * This project contains an application demonstrating the use of the

 * FreeRTOS.org mini real time scheduler on the Luminary Micro LM3S811 Eval

 * board.  See http://www.FreeRTOS.org for more information.

 *

 * main() simply sets up the hardware, creates all the demo application tasks,

 * then starts the scheduler.  http://www.freertos.org/a00102.html provides

 * more information on the standard demo tasks.

 *

 * In addition to a subset of the standard demo application tasks, main.c also

 * defines the following tasks:

 *

 * + A 'Print' task.  The print task is the only task permitted to access the

 * LCD - thus ensuring mutual exclusion and consistent access to the resource.

 * Other tasks do not access the LCD directly, but instead send the text they

 * wish to display to the print task.  The print task spends most of its time

 * blocked - only waking when a message is queued for display.

 *

 * + A 'Button handler' task.  The eval board contains a user push button that

 * is configured to generate interrupts.  The interrupt handler uses a

 * semaphore to wake the button handler task - demonstrating how the priority

 * mechanism can be used to defer interrupt processing to the task level.  The

 * button handler task sends a message both to the LCD (via the print task) and

 * the UART where it can be viewed using a dumb terminal (via the UART to USB

 * converter on the eval board).  NOTES:  The dumb terminal must be closed in

 * order to reflash the microcontroller.  A very basic interrupt driven UART

 * driver is used that does not use the FIFO.  19200 baud is used.

 *

 * + A 'check' task.  The check task only executes every five seconds but has a

 * high priority so is guaranteed to get processor time.  Its function is to

 * check that all the other tasks are still operational and that no errors have

 * been detected at any time.  If no errors have every been detected 'PASS' is

 * written to the display (via the print task) - if an error has ever been

 * detected the message is changed to 'FAIL'.  The position of the message is

 * changed for each write.

 */

/* Environment includes. */

#include "DriverLib.h"

/* Scheduler includes. */

#include "FreeRTOS.h"

#include "task.h"

#include "queue.h"

#include "semphr.h"

/* Demo app includes. */

#include "integer.h"

#include "PollQ.h"

#include "semtest.h"

#include "BlockQ.h"

/* Delay between cycles of the 'check' task. */

#define mainCHECK_DELAY                                         ( ( portTickType ) 5000 / portTICK_RATE_MS )

/* UART configuration - note this does not use the FIFO so is not very

efficient. */

#define mainBAUD_RATE                           ( 19200 )

#define mainFIFO_SET                            ( 0x10 )

/* Demo task priorities. */

#define mainQUEUE_POLL_PRIORITY         ( tskIDLE_PRIORITY + 2 )

#define mainCHECK_TASK_PRIORITY         ( tskIDLE_PRIORITY + 3 )

#define mainSEM_TEST_PRIORITY           ( tskIDLE_PRIORITY + 1 )

#define mainBLOCK_Q_PRIORITY            ( tskIDLE_PRIORITY + 2 )

/* Demo board specifics. */

#define mainPUSH_BUTTON             GPIO_PIN_4

/* Misc. */

#define mainQUEUE_SIZE                          ( 3 )

#define mainDEBOUNCE_DELAY                      ( ( portTickType ) 150 / portTICK_RATE_MS )

#define mainNO_DELAY                            ( ( portTickType ) 0 )

/*

 * Configure the processor and peripherals for this demo.

 */

static void prvSetupHardware( void );

/*

 * The 'check' task, as described at the top of this file.

 */

static void vCheckTask( void *pvParameters );

/*

 * The task that is woken by the ISR that processes GPIO interrupts originating

 * from the push button.

 */

static void vButtonHandlerTask( void *pvParameters );

/*

 * The task that controls access to the LCD.

 */

static void vPrintTask( void *pvParameter );

/* String that is transmitted on the UART. */

static portCHAR *cMessage = "Task woken by button interrupt! --- ";

static volatile portCHAR *pcNextChar;

/* The semaphore used to wake the button handler task from within the GPIO

interrupt handler. */

xSemaphoreHandle xButtonSemaphore;

/* The queue used to send strings to the print task for display on the LCD. */

xQueueHandle xPrintQueue;

/*-----------------------------------------------------------*/

int main( void )

{

        /* Configure the clocks, UART and GPIO. */

        prvSetupHardware();

        /* Create the semaphore used to wake the button handler task from the GPIO

        ISR. */

        vSemaphoreCreateBinary( xButtonSemaphore );

        xSemaphoreTake( xButtonSemaphore, 0 );

        /* Create the queue used to pass message to vPrintTask. */

        xPrintQueue = xQueueCreate( mainQUEUE_SIZE, sizeof( portCHAR * ) );

        /* Start the standard demo tasks. */

        vStartIntegerMathTasks( tskIDLE_PRIORITY );

        vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );

        vStartSemaphoreTasks( mainSEM_TEST_PRIORITY );

        vStartBlockingQueueTasks( mainBLOCK_Q_PRIORITY );

        /* Start the tasks defined within the file. */

        xTaskCreate( vCheckTask, "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );

        xTaskCreate( vButtonHandlerTask, "Status", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY + 1, NULL );

        xTaskCreate( vPrintTask, "Print", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY - 1, NULL );

        /* Start the scheduler. */

        vTaskStartScheduler();

        /* Will only get here if there was insufficient heap to start the

        scheduler. */

        return 0;

}

/*-----------------------------------------------------------*/

static void vCheckTask( void *pvParameters )

{

portBASE_TYPE xErrorOccurred = pdFALSE;

portTickType xLastExecutionTime;

const portCHAR *pcPassMessage = "PASS";

const portCHAR *pcFailMessage = "FAIL";

        /* Initialise xLastExecutionTime so the first call to vTaskDelayUntil()

        works correctly. */

        xLastExecutionTime = xTaskGetTickCount();

        for( ;; )

        {

                /* Perform this check every mainCHECK_DELAY milliseconds. */

                vTaskDelayUntil( &xLastExecutionTime, mainCHECK_DELAY );

                /* Has an error been found in any task? */

                if( xAreIntegerMathsTaskStillRunning() != pdTRUE )

                {

                        xErrorOccurred = pdTRUE;

                }

                if( xArePollingQueuesStillRunning() != pdTRUE )

                {

                        xErrorOccurred = pdTRUE;

                }

                if( xAreSemaphoreTasksStillRunning() != pdTRUE )

                {

                        xErrorOccurred = pdTRUE;

                }

                if( xAreBlockingQueuesStillRunning() != pdTRUE )

                {

                        xErrorOccurred = pdTRUE;

                }

                /* Send either a pass or fail message.  If an error is found it is

                never cleared again.  We do not write directly to the LCD, but instead

                queue a message for display by the print task. */

                if( xErrorOccurred == pdTRUE )

                {

                        xQueueSend( xPrintQueue, &pcFailMessage, portMAX_DELAY );

                }

                else

                {

                        xQueueSend( xPrintQueue, &pcPassMessage, portMAX_DELAY );

                }

        }

}

/*-----------------------------------------------------------*/

static void prvSetupHardware( void )

{

        /* Setup the PLL. */

        SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ );

        /* Setup the push button. */

        SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);

    GPIODirModeSet(GPIO_PORTC_BASE, mainPUSH_BUTTON, GPIO_DIR_MODE_IN);

        GPIOIntTypeSet( GPIO_PORTC_BASE, mainPUSH_BUTTON,GPIO_FALLING_EDGE );

        IntPrioritySet( INT_GPIOC, configKERNEL_INTERRUPT_PRIORITY );

        GPIOPinIntEnable( GPIO_PORTC_BASE, mainPUSH_BUTTON );

        IntEnable( INT_GPIOC );

        /* Enable the UART.  */

        SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

        SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

        /* Set GPIO A0 and A1 as peripheral function.  They are used to output the

        UART signals. */

        GPIODirModeSet( GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1, GPIO_DIR_MODE_HW );

        /* Configure the UART for 8-N-1 operation. */

        UARTConfigSet( UART0_BASE, mainBAUD_RATE, UART_CONFIG_WLEN_8 | UART_CONFIG_PAR_NONE | UART_CONFIG_STOP_ONE );

        /* We don't want to use the fifo.  This is for test purposes to generate

        as many interrupts as possible. */

        HWREG( UART0_BASE + UART_O_LCR_H ) &= ~mainFIFO_SET;

        /* Enable Tx interrupts. */

        HWREG( UART0_BASE + UART_O_IM ) |= UART_INT_TX;

        IntPrioritySet( INT_UART0, configKERNEL_INTERRUPT_PRIORITY );

        IntEnable( INT_UART0 );

        /* Initialise the LCD> */

    OSRAMInit( false );

    OSRAMStringDraw("www.FreeRTOS.org", 0, 0);

        OSRAMStringDraw("LM3S811 demo", 16, 1);

}

/*-----------------------------------------------------------*/

static void vButtonHandlerTask( void *pvParameters )

{

const portCHAR *pcInterruptMessage = "Int";

        for( ;; )

        {

                /* Wait for a GPIO interrupt to wake this task. */

                while( xSemaphoreTake( xButtonSemaphore, portMAX_DELAY ) != pdPASS );

                /* Start the Tx of the message on the UART. */

                UARTIntDisable( UART0_BASE, UART_INT_TX );

                {

                        pcNextChar = cMessage;

                        /* Send the first character. */

                        if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )

                        {

                                HWREG( UART0_BASE + UART_O_DR ) = *pcNextChar;

                        }

                        pcNextChar++;

                }

                UARTIntEnable(UART0_BASE, UART_INT_TX);

                /* Queue a message for the print task to display on the LCD. */

                xQueueSend( xPrintQueue, &pcInterruptMessage, portMAX_DELAY );

                /* Make sure we don't process bounces. */

                vTaskDelay( mainDEBOUNCE_DELAY );

                xSemaphoreTake( xButtonSemaphore, mainNO_DELAY );

        }

}

/*-----------------------------------------------------------*/

void vUART_ISR(void)

{

unsigned portLONG ulStatus;

        /* What caused the interrupt. */

        ulStatus = UARTIntStatus( UART0_BASE, pdTRUE );

        /* Clear the interrupt. */

        UARTIntClear( UART0_BASE, ulStatus );

        /* Was a Tx interrupt pending? */

        if( ulStatus & UART_INT_TX )

        {

                /* Send the next character in the string.  We are not using the FIFO. */

                if( *pcNextChar != 0 )

                {

                        if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )

                        {

                                HWREG( UART0_BASE + UART_O_DR ) = *pcNextChar;

                        }

                        pcNextChar++;

                }

        }

}

/*-----------------------------------------------------------*/

void vGPIO_ISR( void )

{

portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

        /* Clear the interrupt. */

        GPIOPinIntClear(GPIO_PORTC_BASE, mainPUSH_BUTTON);

        /* Wake the button handler task. */

        xSemaphoreGiveFromISR( xButtonSemaphore, &xHigherPriorityTaskWoken );

        portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );

}

/*-----------------------------------------------------------*/

static void vPrintTask( void *pvParameters )

{

portCHAR *pcMessage;

unsigned portBASE_TYPE uxLine = 0, uxRow = 0;

        for( ;; )

        {

                /* Wait for a message to arrive. */

                xQueueReceive( xPrintQueue, &pcMessage, portMAX_DELAY );

                /* Write the message to the LCD. */

                uxRow++;

                uxLine++;

                OSRAMClear();

                OSRAMStringDraw( pcMessage, uxLine & 0x3f, uxRow & 0x01);

        }

}