/*
	FreeRTOS.org V4.8.1 - Copyright (C) 2003-2008 Richard Barry.

	This file is part of the FreeRTOS.org distribution.

	FreeRTOS.org is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	FreeRTOS.org 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
	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 can be applied should you wish 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 of how and when the exception
	can be applied.

	***************************************************************************
	See http://www.FreeRTOS.org for documentation, latest information, license
	and contact details.  Please ensure to read the configuration and relevant
	port sections of the online documentation.
	***************************************************************************
*/

/* Kernel includes. */
#include "FreeRTOS.h"
#include "Semphr.h"
#include "task.h"

/* Demo includes. */
#include "emac.h"

/* uIP includes. */
#include "uip.h"

/* Hardware library includes. */
#include "hw_types.h"
#include "hw_memmap.h"
#include "hw_ints.h"
#include "hw_ethernet.h"
#include "ethernet.h"
#include "interrupt.h"

#define emacNUM_RX_BUFFERS		5
#define emacFRAM_SIZE_BYTES 	2
#define macNEGOTIATE_DELAY 		2000
#define macWAIT_SEND_TIME		( 10 )

/* The task that handles the MAC peripheral.  This is created at a high
priority and is effectively a deferred interrupt handler.  The peripheral
handling is deferred to a task to prevent the entire FIFO having to be read
from within an ISR. */
void vMACHandleTask( void *pvParameters );

/*-----------------------------------------------------------*/

/* The semaphore used to wake the uIP task when data arrives. */
xSemaphoreHandle xEMACSemaphore = NULL;

/* The semaphore used to wake the interrupt handler task.  The peripheral
is processed at the task level to prevent the need to read the entire FIFO from
within the ISR itself. */
xSemaphoreHandle xMACInterruptSemaphore = NULL;

/* The buffer used by the uIP stack.  In this case the pointer is used to
point to one of the Rx buffers. */
unsigned portCHAR *uip_buf;

/* Buffers into which Rx data is placed. */
static unsigned portCHAR ucRxBuffers[ emacNUM_RX_BUFFERS ][ UIP_BUFSIZE + ( 4 * emacFRAM_SIZE_BYTES ) ];

/* The length of the data within each of the Rx buffers. */
static unsigned portLONG ulRxLength[ emacNUM_RX_BUFFERS ];

/* Used to keep a track of the number of bytes to transmit. */
static unsigned portLONG ulNextTxSpace;

/*-----------------------------------------------------------*/

portBASE_TYPE vInitEMAC( void )
{
unsigned long ulTemp;
portBASE_TYPE xReturn;

	/* Ensure all interrupts are disabled. */
	EthernetIntDisable( ETH_BASE, ( ETH_INT_PHY | ETH_INT_MDIO | ETH_INT_RXER | ETH_INT_RXOF | ETH_INT_TX | ETH_INT_TXER | ETH_INT_RX));

	/* Clear any interrupts that were already pending. */
    ulTemp = EthernetIntStatus( ETH_BASE, pdFALSE );
    EthernetIntClear( ETH_BASE, ulTemp );

	/* Initialise the MAC and connect. */
    EthernetInit( ETH_BASE );
    EthernetConfigSet( ETH_BASE, ( ETH_CFG_TX_DPLXEN | ETH_CFG_TX_CRCEN | ETH_CFG_TX_PADEN ) );
    EthernetEnable( ETH_BASE );

	/* Mark each Rx buffer as empty. */
	for( ulTemp = 0; ulTemp < emacNUM_RX_BUFFERS; ulTemp++ )
	{
		ulRxLength[ ulTemp ] = 0;
	}
	
	/* Create the queue and task used to defer the MAC processing to the
	task level. */
	vSemaphoreCreateBinary( xMACInterruptSemaphore );
	xSemaphoreTake( xMACInterruptSemaphore, 0 );
	xReturn = xTaskCreate( vMACHandleTask, ( signed portCHAR * ) "MAC", configMINIMAL_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL );
	vTaskDelay( macNEGOTIATE_DELAY );
	
	/* We are only interested in Rx interrupts. */
	IntPrioritySet( INT_ETH, configKERNEL_INTERRUPT_PRIORITY );
    IntEnable( INT_ETH );
    EthernetIntEnable(ETH_BASE, ETH_INT_RX);

	return xReturn;
}
/*-----------------------------------------------------------*/

unsigned int uiGetEMACRxData( unsigned char *ucBuffer )
{
static unsigned long ulNextRxBuffer = 0;
unsigned int iLen;

	iLen = ulRxLength[ ulNextRxBuffer ];

	if( iLen != 0 )
	{
		/* Leave room for the size at the start of the buffer. */
		uip_buf = &( ucRxBuffers[ ulNextRxBuffer ][ 2 ] );
		
		ulRxLength[ ulNextRxBuffer ] = 0;
		
		ulNextRxBuffer++;
		if( ulNextRxBuffer >= emacNUM_RX_BUFFERS )
		{
			ulNextRxBuffer = 0;
		}
	}

    return iLen;
}
/*-----------------------------------------------------------*/

void vInitialiseSend( void )
{
	/* Set the index to the first byte to send - skipping over the size
	bytes. */
	ulNextTxSpace = 2;
}
/*-----------------------------------------------------------*/

void vIncrementTxLength( unsigned portLONG ulLength )
{
	ulNextTxSpace += ulLength;
}
/*-----------------------------------------------------------*/

void vSendBufferToMAC( void )
{
unsigned long *pulSource;
unsigned portSHORT * pus;
unsigned portLONG ulNextWord;

	/* Locate the data to be send. */
	pus = ( unsigned portSHORT * ) uip_buf;

	/* Add in the size of the data. */
	pus--;
	*pus = ulNextTxSpace;

	/* Wait for data to be sent if there is no space immediately. */
    while( !EthernetSpaceAvail( ETH_BASE ) )
    {
		vTaskDelay( macWAIT_SEND_TIME );
    }
	
	pulSource = ( unsigned portLONG * ) pus;	
	
	for( ulNextWord = 0; ulNextWord < ulNextTxSpace; ulNextWord += sizeof( unsigned portLONG ) )
	{
       	HWREG(ETH_BASE + MAC_O_DATA) = *pulSource;
		pulSource++;
	}

	/* Go. */
    HWREG( ETH_BASE + MAC_O_TR ) = MAC_TR_NEWTX;
}
/*-----------------------------------------------------------*/

void vEMAC_ISR( void )
{
portBASE_TYPE xSwitchRequired = pdFALSE;
unsigned portLONG ulTemp;

	/* Clear the interrupt. */
	ulTemp = EthernetIntStatus( ETH_BASE, pdFALSE );
	EthernetIntClear( ETH_BASE, ulTemp );
		
	/* Was it an Rx interrupt? */
	if( ulTemp & ETH_INT_RX )
	{
		xSwitchRequired = pdTRUE;
		xSemaphoreGiveFromISR( xMACInterruptSemaphore, pdFALSE );
		EthernetIntDisable( ETH_BASE, ETH_INT_RX );
	}
		
    /* Switch to the uIP task. */
	portEND_SWITCHING_ISR( xSwitchRequired );
}
/*-----------------------------------------------------------*/

void vMACHandleTask( void *pvParameters )
{
unsigned long i;
unsigned portLONG ulLength;
unsigned long *pulBuffer;
static unsigned portLONG ulNextRxBuffer = 0;

	for( ;; )
	{
		/* Wait for something to do. */
		xSemaphoreTake( xMACInterruptSemaphore, portMAX_DELAY );
		
		while( ( EthernetIntStatus( ETH_BASE, pdFALSE ) & ETH_INT_RX ) != 0 )
		{		
			ulLength = HWREG( ETH_BASE + MAC_O_DATA );
			
			/* Leave room at the start of the buffer for the size. */
			pulBuffer = ( unsigned long * ) &( ucRxBuffers[ ulNextRxBuffer ][ 2 ] );			
			*pulBuffer = ( ulLength >> 16 );

			/* Get the size of the data. */			
			pulBuffer = ( unsigned long * ) &( ucRxBuffers[ ulNextRxBuffer ][ 4 ] );			
			ulLength &= 0xFFFF;
			
			if( ulLength > 4 )
			{
				ulLength -= 4;
				
				if( ulLength >= UIP_BUFSIZE )
				{
					/* The data won't fit in our buffer.  Ensure we don't
					try to write into the buffer. */
					ulLength = 0;
				}

				/* Read out the data into our buffer. */
				for( i = 0; i < ulLength; i += sizeof( unsigned portLONG ) )
				{
					*pulBuffer = HWREG( ETH_BASE + MAC_O_DATA );
					pulBuffer++;
				}
				
				/* Store the length of the data into the separate array. */
				ulRxLength[ ulNextRxBuffer ] = ulLength;
				
				/* Use the next buffer the next time through. */
				ulNextRxBuffer++;
				if( ulNextRxBuffer >= emacNUM_RX_BUFFERS )
				{
					ulNextRxBuffer = 0;
				}
		
				/* Ensure the uIP task is not blocked as data has arrived. */
				xSemaphoreGive( xEMACSemaphore );
			}
		}
		
		EthernetIntEnable( ETH_BASE, ETH_INT_RX );
	}
}

