/*
    FreeRTOS V7.4.0 - Copyright (C) 2013 Real Time Engineers Ltd.

    FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT
    http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS tutorial books are available in pdf and paperback.        *
     *    Complete, revised, and edited pdf reference manuals are also       *
     *    available.                                                         *
     *                                                                       *
     *    Purchasing FreeRTOS documentation will not only help you, by       *
     *    ensuring you get running as quickly as possible and with an        *
     *    in-depth knowledge of how to use FreeRTOS, it will also help       *
     *    the FreeRTOS project to continue with its mission of providing     *
     *    professional grade, cross platform, de facto standard solutions    *
     *    for microcontrollers - completely free of charge!                  *
     *                                                                       *
     *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
     *                                                                       *
     *    Thank you for using FreeRTOS, and 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 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.  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 itcan be
    viewed here: http://www.freertos.org/a00114.html and also obtained by
    writing to Real Time Engineers Ltd., contact details for whom are available
    on the FreeRTOS WEB site.

    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, and our new
    fully thread aware and reentrant UDP/IP stack.

    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High 
    Integrity Systems, who sell the code with commercial support, 
    indemnification and middleware, under the OpenRTOS brand.
    
    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.
*/

/*
	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 long 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 char ) );
	xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );

	/* 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 char *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 char * const pcString, unsigned short usStringLength )
{
signed char *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 char * ) pcString;
	while( *pxNext )
	{
		xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
		pxNext++;
	}
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char 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 char 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 );
}