/*
    FreeRTOS V7.5.1 - Copyright (C) 2013 Real Time Engineers Ltd.

    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.             *
     *                                                                       *
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     *    project by purchasing a FreeRTOS tutorial book, reference          *
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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 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
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    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                               *
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    ***************************************************************************

    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
    license and Real Time Engineers Ltd. contact details.

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    1 tab == 4 spaces!
*/


/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER for port 1.

Note that this driver is written to test the RTOS port and is not intended
to represent an optimised solution. */

/* Processor Expert generated includes. */
#include "com0.h"

/* Scheduler include files. */
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"

/* Demo application include files. */
#include "serial.h"

/* The queues used to communicate between the task code and the interrupt
service routines. */
static xQueueHandle xRxedChars; 
static xQueueHandle xCharsForTx; 

/* Interrupt identification bits. */
#define serOVERRUN_INTERRUPT		( 0x08 )
#define serRX_INTERRUPT				( 0x20 )
#define serTX_INTERRUPT				( 0x80 )

/*-----------------------------------------------------------*/


/*
 * Initialise port for interrupt driven communications.
 */
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
	/* Hardware setup is performed by the Processor Expert generated code.  
	This function just creates the queues used to communicate between the 
	interrupt code and the task code - then sets the required baud rate. */

	xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
	xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );

	COM0_SetBaudRateMode( ( char ) ulWantedBaud );

	return NULL;
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
{
	/* Get the next character from the buffer queue.  Return false if no characters
	are available, or arrive before xBlockTime expires. */
	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
	{
		return pdTRUE;
	}
	else
	{
		return pdFALSE;
	}
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
{
	/* Place the character in the queue of characters to be transmitted. */
	if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
	{
		return pdFAIL;
	}

	/* Turn on the Tx interrupt so the ISR will remove the character from the
	queue and send it.   This does not need to be in a critical section as
	if the interrupt has already removed the character the next interrupt
	will simply turn off the Tx interrupt again. */
	SCI0CR2_SCTIE = 1;;

	return pdPASS;
}
/*-----------------------------------------------------------*/

void vSerialClose( xComPortHandle xPort )
{	
	/* Not supported. */
	( void ) xPort;
}
/*-----------------------------------------------------------*/


/* 
 * Interrupt service routine for the serial port.  Must be in non-banked
 * memory. 
 */

#pragma CODE_SEG __NEAR_SEG NON_BANKED

__interrupt void vCOM0_ISR( void )
{
volatile unsigned char ucByte, ucStatus;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	/* What caused the interrupt? */
	ucStatus = SCI0SR1;
	
	if( ucStatus & serOVERRUN_INTERRUPT )
	{
		/* The interrupt was caused by an overrun.  Clear the error by reading
		the data register. */
		ucByte = SCI0DRL;
	}

	if( ucStatus & serRX_INTERRUPT )
	{	
		/* The interrupt was caused by a character being received.
		Read the received byte. */
		ucByte = SCI0DRL;                      

		/* Post the character onto the queue of received characters - noting
		whether or not this wakes a task. */
		xQueueSendFromISR( xRxedChars, ( void * ) &ucByte, &xHigherPriorityTaskWoken );
	}
	
	if( ( ucStatus & serTX_INTERRUPT ) && ( SCI0CR2_SCTIE ) )
	{	
		/* The interrupt was caused by a character being transmitted. */
		if( xQueueReceiveFromISR( xCharsForTx, ( void * ) &ucByte, &xHigherPriorityTaskWoken ) == pdTRUE )
		{
			/* Clear the SCRF bit. */
			SCI0DRL = ucByte;
		}
		else
		{
			/* Disable transmit interrupt */
			SCI0CR2_SCTIE = 0;                 
		}
	}

	if( xHigherPriorityTaskWoken )
	{
		portYIELD();
	}
}

#pragma CODE_SEG DEFAULT