/*
    FreeRTOS V6.1.0 - Copyright (C) 2010 Real Time Engineers Ltd.

    ***************************************************************************
    *                                                                         *
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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.

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*/

/* 
 * This demo application creates eight co-routines and four tasks (five 
 * including the idle task).  The co-routines execute as part of the idle task 
 * hook.  The application is limited in size to allow its compilation using
 * the KickStart version of the IAR compiler.
 *
 * Six of the created co-routines are the standard 'co-routine flash' 
 * co-routines contained within the Demo/Common/Minimal/crflash.c file and 
 * documented on the FreeRTOS.org WEB site.  
 *
 * The 'LCD Task' waits on a message queue for messages informing it what and
 * where to display text.  This is the only task that accesses the LCD
 * so mutual exclusion is guaranteed.
 *
 * The 'LCD Message Task' periodically sends strings to the LCD Task using
 * the message queue.  The strings are rotated to form a short message and
 * are written to the top row of the LCD.
 *
 * The 'ADC Co-routine' periodically reads the ADC input that is connected to
 * the light sensor, forms a short message from the value, and then sends this
 * message to the LCD Task using the same message queue.  The ADC readings are
 * displayed on the bottom row of the LCD.  
 *
 * The eighth co-routine and final task control the transmission and reception
 * of a string to UART 0.  The co-routine periodically sends the first 
 * character of the string to the UART, with the UART's TxEnd interrupt being
 * used to transmit the remaining characters.  The UART's RxEnd interrupt 
 * receives the characters and places them on a queue to be processed by the 
 * 'COMs Rx' task.  An error is latched should an unexpected character be 
 * received, or any character be received out of sequence.  
 *
 * A loopback connector is required to ensure that each character transmitted 
 * on the UART is also received on the same UART.  For test purposes the UART
 * FIFO's are not utalised in order to maximise the interrupt overhead.  Also
 * a pseudo random interval is used between the start of each transmission in 
 * order that the resultant interrupts are more randomly distributed and 
 * therefore more likely to highlight any problems.
 *
 * The flash co-routines control LED's zero to four.  LED five is toggled each
 * time the string is transmitted on the UART.  LED six is toggled each time
 * the string is CORRECTLY received on the UART.  LED seven is latched on 
 * should an error be detected in any task or co-routine.
 *
 * In addition the idle task makes repetitive calls to 
 * vSetAndCheckRegisters().  This simply loads the general purpose registers 
 * with a known value, then checks each register to ensure the held value is 
 * still correct.  As a low priority task this checking routine is likely to 
 * get repeatedly swapped in and out.  A register being found to contain an 
 * incorrect value is therefore indicative of an error in the task switching 
 * mechanism.
 *
 */

/* standard include files. */
#include <stdio.h>

/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "croutine.h"

/* Demo application include files. */
#include "partest.h"
#include "crflash.h"
#include "commstest.h"

/* Library include files. */
#include "DriverLib.h"

/* The time to delay between writing each character to the LCD. */
#define mainCHAR_WRITE_DELAY		( 2 / portTICK_RATE_MS )

/* The time to delay between writing each string to the LCD. */
#define mainSTRING_WRITE_DELAY		( 400 / portTICK_RATE_MS )

#define mainADC_DELAY				( 200 / portTICK_RATE_MS )

/* The number of flash co-routines to create. */
#define mainNUM_FLASH_CO_ROUTINES	( 5 )

/* The length of the queue used to send messages to the LCD task. */
#define mainLCD_QUEUE_LEN			( 3 )

/* The priority of the co-routine used to initiate the transmission of the 
string on UART 0. */
#define mainTX_CO_ROUTINE_PRIORITY	( 1 )
#define mainADC_CO_ROUTINE_PRIORITY 	( 2 )

/* Only one of each co-routine is created so its index is not important. */
#define mainTX_CO_ROUTINE_INDEX		( 0 )
#define mainADC_CO_ROUTINE_INDEX  	( 0 )

/* The task priorities. */
#define mainLCD_TASK_PRIORITY		( tskIDLE_PRIORITY + 1 )
#define mainMSG_TASK_PRIORITY		( mainLCD_TASK_PRIORITY - 1 )
#define mainCOMMS_RX_TASK_PRIORITY	( tskIDLE_PRIORITY + 1 )

/* The LCD had two rows. */
#define mainTOP_ROW		0
#define mainBOTTOM_ROW 	1

/* Dimension for the buffer into which the ADC value string is written. */
#define mainMAX_ADC_STRING_LEN	20

/* The LED that is lit should an error be detected in any of the tasks or
co-routines. */
#define mainFAIL_LED			( 7 )

/*-----------------------------------------------------------*/

/*
 * The task that displays text on the LCD.
 */
static void prvLCDTask( void * pvParameters );

/*
 * The task that sends messages to be displayed on the top row of the LCD.
 */
static void prvLCDMessageTask( void * pvParameters );

/*
 * The co-routine that reads the ADC and sends messages for display on the
 * bottom row of the LCD.
 */
static void prvADCCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );

/*
 * Function to simply set a known value into the general purpose registers
 * then read them back to ensure they remain set correctly.  An incorrect value
 * being indicative of an error in the task switching mechanism.
 */
extern void vSetAndCheckRegisters( void );

/*
 * Latch the LED that indicates that an error has occurred. 
 */
void vSetErrorLED( void );

/*
 * Thread safe write to the PDC.
 */
static void prvPDCWrite( char cAddress, char cData );

/*
 * Sets up the hardware used by the demo.
 */
static void prvSetupHardware( void );


/*-----------------------------------------------------------*/

/* The structure that is passed on the LCD message queue. */
typedef struct
{
	char **ppcMessageToDisplay; /*<< Points to a char* pointing to the message to display. */
	portBASE_TYPE xRow;				/*<< The row on which the message should be displayed. */
} xLCDMessage;

/* Error flag set to pdFAIL if an error is encountered in the tasks/co-routines
defined within this file. */
unsigned portBASE_TYPE uxErrorStatus = pdPASS;

/* The queue used to transmit messages to the LCD task. */
static xQueueHandle xLCDQueue;

/*-----------------------------------------------------------*/

/*
 * Setup the hardware, create the tasks/co-routines, then start the scheduler.
 */
void main( void )
{
	/* Create the queue used by tasks wanting to write to the LCD. */
	xLCDQueue = xQueueCreate( mainLCD_QUEUE_LEN, sizeof( xLCDMessage ) );

	/* Setup the ports used by the demo and the clock. */
	prvSetupHardware();

	/* Create the co-routines that flash the LED's. */
	vStartFlashCoRoutines( mainNUM_FLASH_CO_ROUTINES );

	/* Create the co-routine that initiates the transmission of characters
	on the UART and the task that receives them, as described at the top of
	this file. */
	xCoRoutineCreate( vSerialTxCoRoutine, mainTX_CO_ROUTINE_PRIORITY, mainTX_CO_ROUTINE_INDEX );
	xTaskCreate( vCommsRxTask, "CMS", configMINIMAL_STACK_SIZE, NULL, mainCOMMS_RX_TASK_PRIORITY, NULL );

	/* Create the task that waits for messages to display on the LCD, plus the
	task and co-routine that send messages for display (as described at the top
	of this file. */
	xTaskCreate( prvLCDTask, "LCD", configMINIMAL_STACK_SIZE, ( void * ) &xLCDQueue, mainLCD_TASK_PRIORITY, NULL );
	xTaskCreate( prvLCDMessageTask, "MSG", configMINIMAL_STACK_SIZE, ( void * ) &xLCDQueue, mainMSG_TASK_PRIORITY, NULL );
	xCoRoutineCreate( prvADCCoRoutine, mainADC_CO_ROUTINE_PRIORITY, mainADC_CO_ROUTINE_INDEX );

	/* Start the scheduler running the tasks and co-routines just created. */
	vTaskStartScheduler();

	/* Should not get here unless we did not have enough memory to start the
	scheduler. */
	for( ;; );
}
/*-----------------------------------------------------------*/

static void prvLCDMessageTask( void * pvParameters )
{
/* The strings that are written to the LCD. */
char *pcStringsToDisplay[] = {										
									"IAR             ",
									"Stellaris       ",
									"Demo            ",
									"www.FreeRTOS.org",
									""
								};

xQueueHandle *pxLCDQueue;	
xLCDMessage xMessageToSend;
portBASE_TYPE xIndex = 0;

	/* To test the parameter passing mechanism, the queue on which messages are
	posted is passed in as a parameter even though it is available as a file
	scope variable anyway. */
	pxLCDQueue = ( xQueueHandle * ) pvParameters;

	for( ;; )
	{
		/* Wait until it is time to move onto the next string. */
		vTaskDelay( mainSTRING_WRITE_DELAY );		
		
		/* Create the message object to send to the LCD task. */
		xMessageToSend.ppcMessageToDisplay = &pcStringsToDisplay[ xIndex ];
		xMessageToSend.xRow = mainTOP_ROW;
		
		/* Post the message to be displayed. */
		if( !xQueueSend( *pxLCDQueue, ( void * ) &xMessageToSend, 0 ) )
		{
			uxErrorStatus = pdFAIL;
		}
		
		/* Move onto the next message, wrapping when necessary. */
		xIndex++;		
		if( *( pcStringsToDisplay[ xIndex ] ) == 0x00 )
		{
			xIndex = 0;

			/* Delay longer before going back to the start of the messages. */
			vTaskDelay( mainSTRING_WRITE_DELAY * 2 );
		}
	}
}
/*-----------------------------------------------------------*/

void prvLCDTask( void * pvParameters )
{
unsigned portBASE_TYPE uxIndex;
xQueueHandle *pxLCDQueue;
xLCDMessage xReceivedMessage;
char *pcString;
const unsigned char ucCFGData[] = {	
											0x30,   /* Set data bus to 8-bits. */
											0x30,
											0x30,
											0x3C,   /* Number of lines/font. */
											0x08,   /* Display off. */
											0x01,   /* Display clear. */
											0x06,   /* Entry mode [cursor dir][shift]. */
											0x0C	/* Display on [display on][curson on][blinking on]. */
									  };  

	/* To test the parameter passing mechanism, the queue on which messages are
	received is passed in as a parameter even though it is available as a file
	scope variable anyway. */
	pxLCDQueue = ( xQueueHandle * ) pvParameters;

	/* Configure the LCD. */
	uxIndex = 0;
	while( uxIndex < sizeof( ucCFGData ) )
	{
		prvPDCWrite( PDC_LCD_CSR, ucCFGData[ uxIndex ] );
		uxIndex++;
		vTaskDelay( mainCHAR_WRITE_DELAY );
	}

	/* Turn the LCD Backlight on. */
	prvPDCWrite( PDC_CSR, 0x01 );

	/* Clear display. */
	vTaskDelay( mainCHAR_WRITE_DELAY );
	prvPDCWrite( PDC_LCD_CSR, LCD_CLEAR ); 

	uxIndex = 0;
	for( ;; )    
	{
		/* Wait for a message to arrive. */
		if( xQueueReceive( *pxLCDQueue, &xReceivedMessage, portMAX_DELAY ) )
		{
			/* Which row does the received message say to write to? */
			PDCLCDSetPos( 0, xReceivedMessage.xRow );

			/* Where is the string we are going to display? */
			pcString = *xReceivedMessage.ppcMessageToDisplay;
			
			while( *pcString )
			{
				/* Don't write out the string too quickly as LCD's are usually 
				pretty slow devices. */
				vTaskDelay( mainCHAR_WRITE_DELAY );
				prvPDCWrite( PDC_LCD_RAM, *pcString );
				pcString++;
			}		
		}
	}
}
/*-----------------------------------------------------------*/

static void prvADCCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
{
static unsigned long ulADCValue;
static char cMessageBuffer[ mainMAX_ADC_STRING_LEN ];
static char *pcMessage;
static xLCDMessage xMessageToSend;

	/* Co-routines MUST start with a call to crSTART(). */
	crSTART( xHandle );
	
	for( ;; )
	{
		/* Start an ADC conversion. */
		ADCProcessorTrigger( ADC_BASE, 0 );
		
		/* Simply delay - when we unblock the result should be available */	
		crDELAY( xHandle, mainADC_DELAY );
		
		/* Get the ADC result. */
		ADCSequenceDataGet( ADC_BASE, 0, &ulADCValue );

		/* Create a string with the result. */		
		sprintf( cMessageBuffer, "ADC = %d   ", ulADCValue );
		pcMessage = cMessageBuffer;

		/* Configure the message we are going to send for display. */
		xMessageToSend.ppcMessageToDisplay = ( char** ) &pcMessage;
		xMessageToSend.xRow = mainBOTTOM_ROW;
		
		/* Send the string to the LCD task for display.  We are sending
		on a task queue so do not have the option to block. */
		if( !xQueueSend( xLCDQueue, ( void * ) &xMessageToSend, 0 ) )
		{
			uxErrorStatus = pdFAIL;
		}		
	}
	
	/* Co-routines MUST end with a call to crEND(). */
	crEND();
}
/*-----------------------------------------------------------*/

static void prvSetupHardware( void )
{
	/* Setup the PLL. */
	SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ );
	
	/* Initialise the hardware used to talk to the LCD, LED's and UART. */
	PDCInit();
	vParTestInitialise();
	vSerialInit();

	/* The ADC is used to read the light sensor. */
	SysCtlPeripheralEnable( SYSCTL_PERIPH_ADC );
    ADCSequenceConfigure( ADC_BASE, 3, ADC_TRIGGER_PROCESSOR, 0);
    ADCSequenceStepConfigure( ADC_BASE, 0, 0, ADC_CTL_CH0 | ADC_CTL_END );
    ADCSequenceEnable( ADC_BASE, 0 );

}
/*-----------------------------------------------------------*/

static void prvPDCWrite( char cAddress, char cData )
{
	vTaskSuspendAll();
	{
		PDCWrite( cAddress, cData );
	}
	xTaskResumeAll();
}
/*-----------------------------------------------------------*/

void vSetErrorLED( void )
{
	vParTestSetLED( mainFAIL_LED, pdTRUE );
}
/*-----------------------------------------------------------*/

void vApplicationIdleHook( void )
{
	/* The co-routines are executed in the idle task using the idle task 
	hook. */
	for( ;; )
	{
		/* Schedule the co-routines. */
		vCoRoutineSchedule();

		/* Run the register check function between each co-routine. */
		vSetAndCheckRegisters();
		
		/* See if the comms task and co-routine has found any errors. */
		if( uxGetCommsStatus() != pdPASS )
		{
			vParTestSetLED( mainFAIL_LED, pdTRUE );
		}
	}
}
/*-----------------------------------------------------------*/