/*
    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

    ***************************************************************************
    *                                                                         *
    * If you are:                                                             *
    *                                                                         *
    *    + New to FreeRTOS,                                                   *
    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
    *    + Looking for basic training,                                        *
    *    + Wanting to improve your FreeRTOS skills and productivity           *
    *                                                                         *
    * then take a look at the FreeRTOS books - available as PDF or paperback  *
    *                                                                         *
    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
    *                  http://www.FreeRTOS.org/Documentation                  *
    *                                                                         *
    * A pdf reference manual is also available.  Both are usually delivered   *
    * to your inbox within 20 minutes to two hours when purchased between 8am *
    * and 8pm GMT (although please allow up to 24 hours in case of            *
    * exceptional circumstances).  Thank you for your support!                *
    *                                                                         *
    ***************************************************************************

    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.

    http://www.SafeRTOS.com - A version that is certified for use in safety
    critical systems.

    http://www.OpenRTOS.com - Commercial support, development, porting,
    licensing and training services.
*/

/* peripheral library include */
#include <plib.h>

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

/* Demo includes. */
#include "lcd.h"

/*
 * The LCD is written to by more than one task so is controlled by this
 * 'gatekeeper' task.  This is the only task that is actually permitted to
 * access the LCD directly.  Other tasks wanting to display a message send
 * the message to the gatekeeper.
 */
static void vLCDTask( void *pvParameters );

/*
 * Setup the peripherals required to communicate with the LCD.
 */
static void prvSetupLCD( void );

/* 
 * Move to the first (0) or second (1) row of the LCD. 
 */
static void prvLCDGotoRow( unsigned short usRow );

/* 
 * Write a string of text to the LCD. 
 */
static void prvLCDPutString( char *pcString );

/* 
 * Clear the LCD. 
 */
static void prvLCDClear( void );

/*-----------------------------------------------------------*/

/* Brief delay to permit the LCD to catch up with commands. */
#define lcdVERY_SHORT_DELAY	( 1 )
#define lcdSHORT_DELAY		( 4 / portTICK_RATE_MS )
#define lcdLONG_DELAY		( 15 / portTICK_RATE_MS )

/* LCD specific definitions. */
#define LCD_CLEAR_DISPLAY_CMD			0x01
#define LCD_CURSOR_HOME_CMD				0x02
#define LCD_ENTRY_MODE_CMD				0x04
#define LCD_ENTRY_MODE_INCREASE			0x02
#define LCD_DISPLAY_CTRL_CMD			0x08
#define LCD_DISPLAY_CTRL_DISPLAY_ON		0x04
#define LCD_FUNCTION_SET_CMD			0x20
#define LCD_FUNCTION_SET_8_BITS			0x10
#define LCD_FUNCTION_SET_2_LINES		0x08
#define LCD_FUNCTION_SET_LRG_FONT		0x04
#define LCD_NEW_LINE					0xC0
#define LCD_COMMAND_ADDRESS				0x00
#define LCD_DATA_ADDRESS				0x01

/* The length of the queue used to send messages to the LCD gatekeeper task. */
#define lcdQUEUE_SIZE		3

/*-----------------------------------------------------------*/

/* The queue used to send messages to the LCD task. */
xQueueHandle xLCDQueue;

/* LCD access functions. */
static void prvLCDCommand( char cCommand );
static void prvLCDData( char cChar );

/*-----------------------------------------------------------*/

xQueueHandle xStartLCDTask( void )
{
	/* Create the queue used by the LCD task.  Messages for display on the LCD
	are received via this queue. */
	xLCDQueue = xQueueCreate( lcdQUEUE_SIZE, sizeof( xLCDMessage ));

	/* Start the task that will write to the LCD.  The LCD hardware is
	initialised from within the task itself so delays can be used. */
	xTaskCreate( vLCDTask, ( signed char * ) "LCD", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL );

	return xLCDQueue;
}
/*-----------------------------------------------------------*/

static void prvLCDGotoRow( unsigned short usRow )
{
	if(usRow == 0) 
	{
		prvLCDCommand( LCD_CURSOR_HOME_CMD );
	} 
	else 
	{
		prvLCDCommand( LCD_NEW_LINE );
	}
}
/*-----------------------------------------------------------*/

static void prvLCDCommand( char cCommand ) 
{
	PMPSetAddress( LCD_COMMAND_ADDRESS );
	PMPMasterWrite( cCommand );
   	vTaskDelay( lcdSHORT_DELAY );
}
/*-----------------------------------------------------------*/

static void prvLCDData( char cChar )
{
	PMPSetAddress( LCD_DATA_ADDRESS );
	PMPMasterWrite( cChar );
	vTaskDelay( lcdVERY_SHORT_DELAY );
}
/*-----------------------------------------------------------*/

static void prvLCDPutString( char *pcString )
{
	/* Write out each character with appropriate delay between each. */
	while(*pcString)
	{
		prvLCDData(*pcString);
		pcString++;
		vTaskDelay(lcdSHORT_DELAY);
	}
}
/*-----------------------------------------------------------*/

static void prvLCDClear(void)
{
	prvLCDCommand(LCD_CLEAR_DISPLAY_CMD);
}
/*-----------------------------------------------------------*/

static void prvSetupLCD(void)
{
	/* Wait for proper power up. */
	vTaskDelay( lcdLONG_DELAY );
	
	/* Open the PMP port */
	mPMPOpen((PMP_ON | PMP_READ_WRITE_EN | PMP_CS2_CS1_EN |
			  PMP_LATCH_POL_HI | PMP_CS2_POL_HI | PMP_CS1_POL_HI |
			  PMP_WRITE_POL_HI | PMP_READ_POL_HI),
			 (PMP_MODE_MASTER1 | PMP_WAIT_BEG_4 | PMP_WAIT_MID_15 |
			  PMP_WAIT_END_4),
			  PMP_PEN_0, 0);
			 
	/* Wait for the LCD to power up correctly. */
	vTaskDelay( lcdLONG_DELAY );
	vTaskDelay( lcdLONG_DELAY );
	vTaskDelay( lcdLONG_DELAY );

	/* Set up the LCD function. */
	prvLCDCommand( LCD_FUNCTION_SET_CMD | LCD_FUNCTION_SET_8_BITS | LCD_FUNCTION_SET_2_LINES | LCD_FUNCTION_SET_LRG_FONT );
	
	/* Turn the display on. */
	prvLCDCommand( LCD_DISPLAY_CTRL_CMD | LCD_DISPLAY_CTRL_DISPLAY_ON );
	
	/* Clear the display. */
	prvLCDCommand( LCD_CLEAR_DISPLAY_CMD );
	vTaskDelay( lcdLONG_DELAY );	
	
	/* Increase the cursor. */
	prvLCDCommand( LCD_ENTRY_MODE_CMD | LCD_ENTRY_MODE_INCREASE );
	vTaskDelay( lcdLONG_DELAY );		  	
	vTaskDelay( lcdLONG_DELAY );		  	
	vTaskDelay( lcdLONG_DELAY );
}
/*-----------------------------------------------------------*/

static void vLCDTask(void *pvParameters)
{
xLCDMessage xMessage;
unsigned short usRow = 0;

	/* Initialise the hardware.  This uses delays so must not be called prior
	to the scheduler being started. */
	prvSetupLCD();

	/* Welcome message. */
	prvLCDPutString( "www.FreeRTOS.org" );

	for(;;)
	{
		/* Wait for a message to arrive that requires displaying. */
		while( xQueueReceive( xLCDQueue, &xMessage, portMAX_DELAY ) != pdPASS );

		/* Clear the current display value. */
		prvLCDClear();

		/* Switch rows each time so we can see that the display is still being
		updated. */
		prvLCDGotoRow( usRow & 0x01 );
		usRow++;
		prvLCDPutString( xMessage.pcMessage );

		/* Delay the requested amount of time to ensure the text just written 
		to the LCD is not overwritten. */
		vTaskDelay( xMessage.xMinDisplayTime );		
	}
}