/*
    FreeRTOS V8.1.0 - Copyright (C) 2014 Real Time Engineers Ltd. 
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that has become a de facto standard.             *
     *                                                                       *
     *    Help yourself get started quickly and support the FreeRTOS         *
     *    project by purchasing a FreeRTOS tutorial book, reference          *
     *    manual, or both from: http://www.FreeRTOS.org/Documentation        *
     *                                                                       *
     *    Thank you!                                                         *
     *                                                                       *
    ***************************************************************************

    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 modification 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.  Full license text is available from the following
    link: http://www.freertos.org/a00114.html

    1 tab == 4 spaces!

    ***************************************************************************
     *                                                                       *
     *    Having a problem?  Start by reading the FAQ "My application does   *
     *    not run, what could be wrong?"                                     *
     *                                                                       *
     *    http://www.FreeRTOS.org/FAQHelp.html                               *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
    license and Real Time Engineers Ltd. contact details.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
    Integrity Systems to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"

/* Hardware specifics. */
#include "iodefine.h"
#include "lcd.h"

/* States used by the LCD tasks. */
#define	lcdRIGHT_TO_LEFT	0U
#define	lcdLEFT_TO_RIGHT	1U
#define	lcdRUNNING			0U

/* Characters on each line. */
#define lcdSTRING_LEN		8 

/* Commands sent from the IRQ to the task controlling the second line of the
display. */
#define lcdSHIFT_BACK_COMMAND		0x01U
#define lcdSTART_STOP_COMMAND		0x02U
#define lcdSHIFT_FORWARD_COMMAND	0x03U

/* The length of the queue used to send commands from the ISRs. */
#define lcdCOMMAND_QUEUE_LENGTH		32U

/* Defines the minimum time that must pass between consecutive button presses
to accept a button press as a unique press rather than just a bounce. */
#define lcdMIN_TIME_BETWEEN_INTERRUPTS_MS ( 125UL / portTICK_PERIOD_MS )

/* Button interrupt handlers. */
#pragma interrupt ( prvIRQ1_Handler( vect = 65, enable ) )
static void prvIRQ1_Handler( void );

#pragma interrupt ( prvIRQ3_Handler( vect = 67, enable ) )
static void prvIRQ3_Handler( void );

#pragma interrupt ( prvIRQ4_Handler(vect = 68, enable ) )
static void prvIRQ4_Handler( void );

/* 
 * Setup the IO needed for the buttons to generate interrupts. 
 */
static void prvSetupButtonIOAndInterrupts( void );

/*
 * A task that simply scrolls a string from left to right, then back from the
 * right to the left.  This is done on the first line of the display.
 */
static void prvLCDTaskLine1( void *pvParameters );

/*
 * If no buttons are pushed, then this task acts as per prvLCDTaskLine1(), but
 * using the second line of the display.
 *
 * Using the buttons, it is possible to start and stop the scrolling of the 
 * text.  Once the scrolling has been stopped, other buttons can be used to
 * manually scroll the text either left or right.
 */ 
static void prvLCDTaskLine2( void *pvParameters );

/*
 * Looks at the direction the string is currently being scrolled in, and moves
 * the index into the portion of the string that can be seen on the display
 * either forward or backward as appropriate. 
 */
static prvScrollString( unsigned char *pucDirection, unsigned short *pusPosition, size_t xStringLength );

/* 
 * Displays lcdSTRING_LEN characters starting from pcString on the line of the
 * display requested by ucLine.
 */
static void prvDisplayNextString( unsigned char ucLine, char *pcString );

/*
 * Called from the IRQ interrupts, which are generated on button pushes.  Send
 * ucCommand to the task on the button command queue if 
 * lcdMIN_TIME_BETWEEN_INTERRUPTS_MS milliseconds have passed since the button
 * was last pushed (for debouncing). 
 */
static portBASE_TYPE prvSendCommandOnDebouncedInput( TickType_t *pxTimeLastInterrupt, unsigned char ucCommand );

/*-----------------------------------------------------------*/

/* The queue used to pass commands from the button interrupt handlers to the
prvLCDTaskLine2() task. */
static QueueHandle_t xButtonCommandQueue = NULL;

/* The mutex used to ensure only one task writes to the display at any one
time. */
static SemaphoreHandle_t xLCDMutex = NULL;

/* The string that is scrolled up and down the first line of the display. */
static const char cDataString1[] = "        http://www.FreeRTOS.org        ";

/* The string that is scrolled/nudged up and down the second line of the 
display. */
static const char cDataString2[] = "........Rx210 Highlights....1.56 DMips/MHz....DSP functions....1.62V-5.5V operation....200 uA/MHz....Up to 512 kBytes Flash....up to 64 kbytes SRAM....EE Dataflash with 100k w/e....1.3 uA in Real Time Clock Mode....Powerful Motor control timer....4 x 16-bit timers....4 x 8-bit timers....Full Real Time Clock calendar with calibration and alarm functions....Up to 16 channels 1 uS 12-bit ADC, with Dual group programmable SCAN, 3 sample and holds, sample accumulate function....DMA controller....Data Transfer Controller....Up to 9 serial Channels....Up to 6 USARTs ( with Simple I2C / SPI )....USART ( with unique Frame based protocol support )....Multimaster IIC....RSPI....Temperature Sensor....Event Link Controller....Comparators....Safety features include CRC....March X....Dual watchdog Timers with window and independent oscillator....ADC self test....I/O Pin Test....Supported with E1 on chip debugger and RSK210 evaluation system....Rx210 Highlights........";

/* Structures passed into the two tasks to inform them which line to use on the
display, how long to delay for, and which string to use. */
struct _LCD_Params xLCDLine1 = 
{
	LCD_LINE1, 215, ( char * ) cDataString1	
};

struct _LCD_Params xLCDLine2 = 
{
	LCD_LINE2, 350, ( char * ) cDataString2
};


/*-----------------------------------------------------------*/

void vStartButtonAndLCDDemo( void )
{
	prvSetupButtonIOAndInterrupts();
	InitialiseDisplay();

	/* Create the mutex used to guard the LCD. */
	xLCDMutex = xSemaphoreCreateMutex();
	configASSERT( xLCDMutex );
	
	/* Create the queue used to pass commands from the IRQ interrupts to the
	prvLCDTaskLine2() task. */
	xButtonCommandQueue = xQueueCreate( lcdCOMMAND_QUEUE_LENGTH, sizeof( unsigned char ) );
	configASSERT( xButtonCommandQueue );

	/* Start the two tasks as described at the top of this file. */
	xTaskCreate( prvLCDTaskLine1, "LCD1", configMINIMAL_STACK_SIZE * 3, ( void * ) &xLCDLine1, tskIDLE_PRIORITY + 1, NULL );
	xTaskCreate( prvLCDTaskLine2, "LCD2", configMINIMAL_STACK_SIZE * 3, ( void * ) &xLCDLine2, tskIDLE_PRIORITY + 2, NULL );
}
/*-----------------------------------------------------------*/

static void prvLCDTaskLine1( void *pvParameters )
{
struct _LCD_Params *pxLCDParamaters = ( struct _LCD_Params * ) pvParameters;
unsigned short usPosition = 0U;
unsigned char ucDirection = lcdRIGHT_TO_LEFT;
	
	for( ;; )
	{
		vTaskDelay( pxLCDParamaters->Speed / portTICK_PERIOD_MS );		

		/* Write the string. */
		prvDisplayNextString( pxLCDParamaters->Line, &( pxLCDParamaters->ptr_str[ usPosition ] ) );

		/* Move the string in whichever direction the scroll is currently going
		in. */
		prvScrollString( &ucDirection, &usPosition, strlen( pxLCDParamaters->ptr_str ) );
	}
}
/*-----------------------------------------------------------*/

static void prvLCDTaskLine2( void *pvParameters )
{
struct _LCD_Params *pxLCDParamaters = ( struct _LCD_Params * ) pvParameters;
unsigned short usPosition = 0U;
unsigned char ucDirection = lcdRIGHT_TO_LEFT, ucStatus = lcdRUNNING, ucQueueData;
TickType_t xDelayTicks = ( pxLCDParamaters->Speed / portTICK_PERIOD_MS );
	
	for(;;)
	{
		/* Wait for a message from an IRQ handler. */
		if( xQueueReceive( xButtonCommandQueue, &ucQueueData, xDelayTicks ) != pdPASS )
		{
			/* A message was not received before xDelayTicks ticks passed, so
			generate the next string to display and display it. */
			prvDisplayNextString( pxLCDParamaters->Line, &( pxLCDParamaters->ptr_str[ usPosition ] ) );
			
			/* Move the string in whichever direction the scroll is currently 
			going in. */
			prvScrollString( &ucDirection, &usPosition, strlen( pxLCDParamaters->ptr_str ) );			
		}
		else
		{
			/* A command was received.  Process it. */
			switch( ucQueueData )
			{
				case lcdSTART_STOP_COMMAND :

					/* If the LCD is running, top it.  If the LCD is stopped, start
					it. */
					ucStatus = !ucStatus;
					
					if( ucStatus == lcdRUNNING )
					{
						xDelayTicks = ( pxLCDParamaters->Speed / portTICK_PERIOD_MS );
					}
					else
					{
						xDelayTicks = portMAX_DELAY;
					}
					break;

					
				case lcdSHIFT_BACK_COMMAND :

					if( ucStatus != lcdRUNNING )
					{
						/* If not already at the start of the display.... */
						if( usPosition != 0U )
						{
							/* ....move the display position back by one char. */
							usPosition--;												
							prvDisplayNextString( pxLCDParamaters->Line, &( pxLCDParamaters->ptr_str[ usPosition ] ) );
						}
					}
					break;
				
				
				case lcdSHIFT_FORWARD_COMMAND :

					if( ucStatus != lcdRUNNING )
					{
						/* If not already at the end of the display.... */
						if( usPosition != ( strlen( pxLCDParamaters->ptr_str ) - ( lcdSTRING_LEN - 1 ) ) )
						{
							/* ....move the display position forward by one 
							char. */
							usPosition++;
							prvDisplayNextString( pxLCDParamaters->Line, &( pxLCDParamaters->ptr_str[ usPosition ] ) );
						}
					}
					break;
			}
		}
	}
}
/*-----------------------------------------------------------*/

void prvSetupButtonIOAndInterrupts( void )
{
	/* Configure SW 1-3 pin settings */
	PORT3.PDR.BIT.B1 = 0;		/* Switch 1 - Port 3.1 - IRQ1 */
	PORT3.PDR.BIT.B3 = 0;		/* Switch 2 - Port 3.3 - IRQ3 */
	PORT3.PDR.BIT.B4 = 0;		/* Switch 3 - Port 3.4 - IRQ4 */

	PORT3.PMR.BIT.B1 = 1;
	PORT3.PMR.BIT.B3 = 1;
	PORT3.PMR.BIT.B4 = 1;

	MPC.PWPR.BIT.B0WI = 0;		/* Writing to the PFSWE bit is enabled */
	MPC.PWPR.BIT.PFSWE = 1;		/* Writing to the PFS register is enabled */
	MPC.P31PFS.BIT.ISEL = 1;
	MPC.P33PFS.BIT.ISEL = 1;
	MPC.P34PFS.BIT.ISEL = 1;

	/* IRQ1	*/
	ICU.IER[ 0x08 ].BIT.IEN1 = 1;	
	ICU.IPR[ 65 ].BIT.IPR = configMAX_SYSCALL_INTERRUPT_PRIORITY - 1;
	ICU.IR[ 65 ].BIT.IR = 0;
	ICU.IRQCR[ 1 ].BIT.IRQMD = 2;	/* Rising edge */

	/* IRQ3	*/
	ICU.IER[ 0x08 ].BIT.IEN3 = 1;	
	ICU.IPR[ 67 ].BIT.IPR = configMAX_SYSCALL_INTERRUPT_PRIORITY - 1;
	ICU.IR[ 67 ].BIT.IR = 0;
	ICU.IRQCR[ 3 ].BIT.IRQMD = 2;	/* Rising edge */

	/* IRQ4	*/
	ICU.IER[ 0x08 ].BIT.IEN4 = 1;	
	ICU.IPR[ 68 ].BIT.IPR = configMAX_SYSCALL_INTERRUPT_PRIORITY - 1;
	ICU.IR[ 68 ].BIT.IR = 0;
	ICU.IRQCR[ 4 ].BIT.IRQMD = 2;	/* Rising edge */
}
/*-----------------------------------------------------------*/

static prvScrollString( unsigned char *pucDirection, unsigned short *pusPosition, size_t xStringLength )
{
	/* Check which way to scroll. */
	if( *pucDirection == lcdRIGHT_TO_LEFT )
	{
		/* Move to the next character. */
		( *pusPosition )++;
		
		/* Has the end of the string been reached? */
		if( ( *pusPosition ) == ( xStringLength - ( lcdSTRING_LEN - 1 ) ) )
		{
			/* Switch direction. */
			*pucDirection = lcdLEFT_TO_RIGHT;
			( *pusPosition )--;				
		}
	}
	else
	{
		/* Move (backward) to the next character. */
		( *pusPosition )--;
		if( *pusPosition == 0U )
		{
			/* Switch Direction. */
			*pucDirection = lcdRIGHT_TO_LEFT;				
		}
	}
}
/*-----------------------------------------------------------*/

static void prvDisplayNextString( unsigned char ucLine, char *pcString )
{
static char cSingleLine[ lcdSTRING_LEN + 1 ];

	xSemaphoreTake( xLCDMutex, portMAX_DELAY );
	strncpy( cSingleLine, pcString, lcdSTRING_LEN );
	DisplayString( ucLine, cSingleLine );
	xSemaphoreGive( xLCDMutex );
}
/*-----------------------------------------------------------*/

static portBASE_TYPE prvSendCommandOnDebouncedInput( TickType_t *pxTimeLastInterrupt, unsigned char ucCommand )
{
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
TickType_t xCurrentTickCount;
	
	/* Check the time now for debouncing purposes. */
	xCurrentTickCount = xTaskGetTickCountFromISR();
	
	/* Has enough time passed since the button was last push to accept it as a
	unique press? */
	if( ( xCurrentTickCount - *pxTimeLastInterrupt ) > lcdMIN_TIME_BETWEEN_INTERRUPTS_MS )
	{
		xQueueSendToBackFromISR( xButtonCommandQueue, &ucCommand, &xHigherPriorityTaskWoken );
	}

	/* Remember the time now, so debounce can be performed again on the next
	interrupt. */	
	*pxTimeLastInterrupt = xCurrentTickCount;
	
	return xHigherPriorityTaskWoken;
}
/*-----------------------------------------------------------*/

static void prvIRQ1_Handler( void )
{
static TickType_t xTimeLastInterrupt = 0UL;
static const unsigned char ucCommand = lcdSHIFT_BACK_COMMAND;
portBASE_TYPE xHigherPriorityTaskWoken;

	xHigherPriorityTaskWoken = prvSendCommandOnDebouncedInput( &xTimeLastInterrupt, ucCommand );
	portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
}
/*-----------------------------------------------------------*/

static void prvIRQ3_Handler(void)
{
static TickType_t xTimeLastInterrupt = 0UL;
static const unsigned char ucCommand = lcdSTART_STOP_COMMAND;
portBASE_TYPE xHigherPriorityTaskWoken;

	xHigherPriorityTaskWoken = prvSendCommandOnDebouncedInput( &xTimeLastInterrupt, ucCommand );
	portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
}
/*-----------------------------------------------------------*/

static void prvIRQ4_Handler(void)
{
static TickType_t xTimeLastInterrupt = 0UL;
static const unsigned char ucCommand = lcdSHIFT_FORWARD_COMMAND;
portBASE_TYPE xHigherPriorityTaskWoken;

	xHigherPriorityTaskWoken = prvSendCommandOnDebouncedInput( &xTimeLastInterrupt, ucCommand );
	portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
}