/*
	FreeRTOS.org V5.2.0 - Copyright (C) 2003-2009 Richard Barry.

	This file is part of the FreeRTOS.org distribution.

	FreeRTOS.org is free software; you can redistribute it and/or modify it 
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	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 along 
	with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59 
	Temple Place, Suite 330, Boston, MA  02111-1307  USA.

	A special exception to the GPL is included to allow you to distribute a 
	combined work that includes FreeRTOS.org without being obliged to provide
	the source code for any proprietary components.  See the licensing section
	of http://www.FreeRTOS.org for full details.


	***************************************************************************
	*                                                                         *
	* Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *
	*                                                                         *
	* This is a concise, step by step, 'hands on' guide that describes both   *
	* general multitasking concepts and FreeRTOS specifics. It presents and   *
	* explains numerous examples that are written using the FreeRTOS API.     *
	* Full source code for all the examples is provided in an accompanying    *
	* .zip file.                                                              *
	*                                                                         *
	***************************************************************************

	1 tab == 4 spaces!

	Please ensure to read the configuration and relevant port sections of the
	online documentation.

	http://www.FreeRTOS.org - Documentation, latest information, license and
	contact details.

	http://www.SafeRTOS.com - A version that is certified for use in safety
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	http://www.OpenRTOS.com - Commercial support, development, porting,
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*/

/*
	BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
*/

/* Library includes. */
#include "75x_uart.h"
#include "75x_gpio.h"
#include "75x_eic.h"
#include "75x_mrcc.h"

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "queue.h"

/* Demo application includes. */
#include "serial.h"

#define serINVALID_QUEUE				( ( xQueueHandle ) 0 )
#define serNO_BLOCK						( ( portTickType ) 0 )

/*-----------------------------------------------------------*/

/* Queues used to hold received characters, and characters waiting to be
transmitted. */
static xQueueHandle xRxedChars;
static xQueueHandle xCharsForTx;

static volatile portBASE_TYPE xQueueEmpty = pdTRUE;

/*-----------------------------------------------------------*/

/* The interrupt service routine - called from the assembly entry point. */
__arm void vSerialISR( void );

/*-----------------------------------------------------------*/

/*
 * See the serial2.h header file.
 */
xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
xComPortHandle xReturn;
UART_InitTypeDef UART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
EIC_IRQInitTypeDef  EIC_IRQInitStructure;	

	/* Create the queues used to hold Rx and Tx characters. */
	xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
	xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );

	/* If the queues were created correctly then setup the serial port
	hardware. */
	if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
	{
		portENTER_CRITICAL();
		{
			/* Enable the UART0 Clock. */
			MRCC_PeripheralClockConfig( MRCC_Peripheral_UART0, ENABLE );
			
			/* Configure the UART0_Tx as alternate function */
			GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
			GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_11;
			GPIO_Init(GPIO0, &GPIO_InitStructure);
			
			/* Configure the UART0_Rx as input floating */
			GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
			GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
			GPIO_Init(GPIO0, &GPIO_InitStructure);
			
			/* Configure UART0. */
			UART_InitStructure.UART_WordLength = UART_WordLength_8D;
			UART_InitStructure.UART_StopBits = UART_StopBits_1;
			UART_InitStructure.UART_Parity = UART_Parity_No;
			UART_InitStructure.UART_BaudRate = ulWantedBaud;
			UART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_None;
			UART_InitStructure.UART_Mode = UART_Mode_Tx_Rx;
			UART_InitStructure.UART_TxFIFOLevel = UART_FIFOLevel_1_2; /* FIFO size 16 bytes, FIFO level 8 bytes */
			UART_InitStructure.UART_RxFIFOLevel = UART_FIFOLevel_1_2; /* FIFO size 16 bytes, FIFO level 8 bytes */
			UART_Init(UART0, &UART_InitStructure);

			/* Enable the UART0 */
			UART_Cmd(UART0, ENABLE);

			/* Configure the IEC for the UART interrupts. */			
			EIC_IRQInitStructure.EIC_IRQChannelCmd = ENABLE;
			EIC_IRQInitStructure.EIC_IRQChannel = UART0_IRQChannel;
			EIC_IRQInitStructure.EIC_IRQChannelPriority = 1;
			EIC_IRQInit(&EIC_IRQInitStructure);
			
			xQueueEmpty = pdTRUE;
			UART_ITConfig( UART0, UART_IT_Transmit | UART_IT_Receive, ENABLE );
		}
		portEXIT_CRITICAL();
	}
	else
	{
		xReturn = ( xComPortHandle ) 0;
	}

	/* This demo file only supports a single port but we have to return
	something to comply with the standard demo header file. */
	return xReturn;
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
{
	/* The port handle is not required as this driver only supports one port. */
	( void ) pxPort;

	/* Get the next character from the buffer.  Return false if no characters
	are available, or arrive before xBlockTime expires. */
	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
	{
		return pdTRUE;
	}
	else
	{
		return pdFALSE;
	}
}
/*-----------------------------------------------------------*/

void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )
{
signed portCHAR *pxNext;

	/* A couple of parameters that this port does not use. */
	( void ) usStringLength;
	( void ) pxPort;

	/* NOTE: This implementation does not handle the queue being full as no
	block time is used! */

	/* The port handle is not required as this driver only supports UART0. */
	( void ) pxPort;

	/* Send each character in the string, one at a time. */
	pxNext = ( signed portCHAR * ) pcString;
	while( *pxNext )
	{
		xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
		pxNext++;
	}
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
{
portBASE_TYPE xReturn;

	/* Place the character in the queue of characters to be transmitted. */
	portENTER_CRITICAL();
	{
		if( xQueueEmpty == pdTRUE )
		{
			UART0->DR = cOutChar;
			xReturn = pdPASS;
		}
		else
		{
			if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
			{
				xReturn = pdFAIL;
			}			
			else
			{
				xReturn = pdPASS;				
			}
		}
		
		xQueueEmpty = pdFALSE;
	}
	portEXIT_CRITICAL();

	return xReturn;
}
/*-----------------------------------------------------------*/

void vSerialClose( xComPortHandle xPort )
{
	/* Not supported as not required by the demo application. */
}
/*-----------------------------------------------------------*/

__arm void vSerialISR( void )
{
signed portCHAR cChar;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	do
	{
		if( UART0->MIS & UART_IT_Transmit )
		{
			/* The interrupt was caused by the THR becoming empty.  Are there any
			more characters to transmit? */
			if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
			{
				/* A character was retrieved from the queue so can be sent to the
				THR now. */
				UART0->DR = cChar;
			}
			else
			{
				xQueueEmpty = pdTRUE;		
			}		

			UART_ClearITPendingBit( UART0, UART_IT_Transmit );
		}
	
		if( UART0->MIS & UART_IT_Receive )
		{
			/* The interrupt was caused by a character being received.  Grab the
			character from the RHR and place it in the queue of received
			characters. */
			cChar = UART0->DR;
			xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
			UART_ClearITPendingBit( UART0, UART_IT_Receive );
		}
	} while( UART0->MIS );

	/* If a task was woken by either a character being received or a character
	being transmitted then we may need to switch to another task. */
	portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
}