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/*
    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
 
    ***************************************************************************
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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 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.
 
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*/
 
/* Hardware specific includes. */
#include "iodefine.h"
#include "typedefine.h"
#include "r_ether.h"
#include "phy.h"
 
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
 
/* uIP includes. */
#include "net/uip.h"
 
/* The time to wait between attempts to obtain a free buffer. */
#define emacBUFFER_WAIT_DELAY_ms		( 3 / portTICK_RATE_MS )
 
/* The number of times emacBUFFER_WAIT_DELAY_ms should be waited before giving
up on attempting to obtain a free buffer all together. */
#define emacBUFFER_WAIT_ATTEMPTS	( 30 )
 
/* The number of Rx descriptors. */
#define emacNUM_RX_DESCRIPTORS	8
 
/* The number of Tx descriptors.  When using uIP there is not point in having
more than two. */
#define emacNUM_TX_BUFFERS	2
 
/* The total number of EMAC buffers to allocate. */
#define emacNUM_BUFFERS		( emacNUM_RX_DESCRIPTORS + emacNUM_TX_BUFFERS )
 
/* The time to wait for the Tx descriptor to become free. */
#define emacTX_WAIT_DELAY_ms ( 10 / portTICK_RATE_MS )
 
/* The total number of times to wait emacTX_WAIT_DELAY_ms for the Tx descriptor to
become free. */
#define emacTX_WAIT_ATTEMPTS ( 50 )
 
/* Only Rx end and Tx end interrupts are used by this driver. */
#define emacTX_END_INTERRUPT	( 1UL << 21UL )
#define emacRX_END_INTERRUPT	( 1UL << 18UL )
 
/*-----------------------------------------------------------*/
 
/* The buffers and descriptors themselves.  */
static volatile ethfifo xRxDescriptors[ emacNUM_RX_DESCRIPTORS ] __attribute__((aligned(16)));
static volatile ethfifo xTxDescriptors[ emacNUM_TX_BUFFERS ] __attribute__((aligned(16)));
static char xEthernetBuffers[ emacNUM_BUFFERS ][ UIP_BUFSIZE ] __attribute__((aligned(16)));
 
/* Used to indicate which buffers are free and which are in use.  If an index
contains 0 then the corresponding buffer in xEthernetBuffers is free, otherwise 
the buffer is in use or about to be used. */
static unsigned char ucBufferInUse[ emacNUM_BUFFERS ];
 
/*-----------------------------------------------------------*/
 
/*
 * Initialise both the Rx and Tx descriptors.
 */
static void prvInitialiseDescriptors( void );
 
/*
 * Return a pointer to a free buffer within xEthernetBuffers.
 */
static unsigned char *prvGetNextBuffer( void );
 
/*
 * Return a buffer to the list of free buffers.
 */
static void prvReturnBuffer( unsigned char *pucBuffer );
 
/*
 * Examine the status of the next Rx FIFO to see if it contains new data.
 */
static unsigned long prvCheckRxFifoStatus( void );
 
/*
 * Setup the microcontroller for communication with the PHY.
 */
static void prvResetMAC( void );
 
/*
 * Configure the Ethernet interface peripherals.
 */
static void prvConfigureEtherCAndEDMAC( void );
 
/*
 * Something has gone wrong with the descriptor usage.  Reset all the buffers
 * and descriptors.
 */
static void prvResetEverything( void );
 
/*
 * Handler for the EMAC peripheral.  See the documentation for this
 * port on http://www.FreeRTOS.org for more information on defining interrupt
 * handlers.
 */
void vEMAC_ISR_Handler( void ) __attribute__((interrupt));
 
/*-----------------------------------------------------------*/
 
/* Points to the Rx descriptor currently in use. */
static ethfifo *pxCurrentRxDesc = NULL;
 
/* The buffer used by the uIP stack to both receive and send.  This points to
one of the Ethernet buffers when its actually in use. */
unsigned char *uip_buf = NULL;
 
/*-----------------------------------------------------------*/
 
void vInitEmac( void )
{
	/* Software reset. */
	prvResetMAC();
 
	/* Set the Rx and Tx descriptors into their initial state. */
	prvInitialiseDescriptors();
 
	/* Set the MAC address into the ETHERC */
	ETHERC.MAHR = 	( ( unsigned long ) configMAC_ADDR0 << 24UL ) | 
					( ( unsigned long ) configMAC_ADDR1 << 16UL ) | 
					( ( unsigned long ) configMAC_ADDR2 << 8UL ) | 
					( unsigned long ) configMAC_ADDR3;
 
	ETHERC.MALR.BIT.MA = ( ( unsigned long ) configMAC_ADDR4 << 8UL ) |
						 ( unsigned long ) configMAC_ADDR5;
 
	/* Perform rest of interface hardware configuration. */
	prvConfigureEtherCAndEDMAC();
 
	/* Nothing received yet, so uip_buf points nowhere. */
	uip_buf = NULL;
 
	/* Initialize the PHY */
	phy_init();
}
/*-----------------------------------------------------------*/
 
void vEMACWrite( void )
{
long x;
 
	/* Wait until the second transmission of the last packet has completed. */
	for( x = 0; x < emacTX_WAIT_ATTEMPTS; x++ )
	{
		if( ( xTxDescriptors[ 1 ].status & ACT ) != 0 )
		{
			/* Descriptor is still active. */
			vTaskDelay( emacTX_WAIT_DELAY_ms );
		}
		else
		{
			break;
		}
	}
 
	/* Is the descriptor free after waiting for it? */
	if( ( xTxDescriptors[ 1 ].status & ACT ) != 0 )
	{
		/* Something has gone wrong. */
		prvResetEverything();
	}
 
	/* Setup both descriptors to transmit the frame. */
	xTxDescriptors[ 0 ].buf_p = ( char * ) uip_buf;
	xTxDescriptors[ 0 ].bufsize = uip_len;	
	xTxDescriptors[ 1 ].buf_p = ( char * ) uip_buf;
	xTxDescriptors[ 1 ].bufsize = uip_len;
 
	/* uip_buf is being sent by the Tx descriptor.  Allocate a new buffer
	for use by the stack. */
	uip_buf = prvGetNextBuffer();
 
	/* Clear previous settings and go. */
	xTxDescriptors[0].status &= ~( FP1 | FP0 );
	xTxDescriptors[0].status |= ( FP1 | FP0 | ACT );
	xTxDescriptors[1].status &= ~( FP1 | FP0 );
	xTxDescriptors[1].status |= ( FP1 | FP0 | ACT );
 
	EDMAC.EDTRR.LONG = 0x00000001;
}
/*-----------------------------------------------------------*/
 
unsigned long ulEMACRead( void )
{
unsigned long ulBytesReceived;
 
	ulBytesReceived = prvCheckRxFifoStatus();
 
	if( ulBytesReceived > 0 )
	{
		pxCurrentRxDesc->status &= ~( FP1 | FP0 );
		pxCurrentRxDesc->status |= ACT;			
 
		if( EDMAC.EDRRR.LONG == 0x00000000L )
		{
			/* Restart Ethernet if it has stopped */
			EDMAC.EDRRR.LONG = 0x00000001L;
		}
 
		/* Mark the pxDescriptor buffer as free as uip_buf is going to be set to
		the buffer that contains the received data. */
		prvReturnBuffer( uip_buf );
 
		uip_buf = ( void * ) pxCurrentRxDesc->buf_p;
 
		/* Move onto the next buffer in the ring. */
		pxCurrentRxDesc = pxCurrentRxDesc->next;
	}
 
	return ulBytesReceived;
}
/*-----------------------------------------------------------*/
 
long lEMACWaitForLink( void )
{
long lReturn;
 
	/* Set the link status. */
	switch( phy_set_autonegotiate() )
	{
		/* Half duplex link */
		case PHY_LINK_100H:
								ETHERC.ECMR.BIT.DM = 0;
								ETHERC.ECMR.BIT.RTM = 1;
								lReturn = pdPASS;
								break;
 
		case PHY_LINK_10H:
								ETHERC.ECMR.BIT.DM = 0;
								ETHERC.ECMR.BIT.RTM = 0;
								lReturn = pdPASS;
								break;
 
 
		/* Full duplex link */
		case PHY_LINK_100F:
								ETHERC.ECMR.BIT.DM = 1;
								ETHERC.ECMR.BIT.RTM = 1;
								lReturn = pdPASS;
								break;
 
		case PHY_LINK_10F:
								ETHERC.ECMR.BIT.DM = 1;
								ETHERC.ECMR.BIT.RTM = 0;
								lReturn = pdPASS;
								break;
 
		default:
								lReturn = pdFAIL;
								break;
	}
 
	if( lReturn == pdPASS )
	{
		/* Enable receive and transmit. */
		ETHERC.ECMR.BIT.RE = 1;
		ETHERC.ECMR.BIT.TE = 1;
 
		/* Enable EDMAC receive */
		EDMAC.EDRRR.LONG = 0x1;
	}
 
	return lReturn;
}
/*-----------------------------------------------------------*/
 
static void prvInitialiseDescriptors( void )
{
volatile ethfifo *pxDescriptor;
long x;
 
	for( x = 0; x < emacNUM_BUFFERS; x++ )
	{
		/* Ensure none of the buffers are shown as in use at the start. */
		ucBufferInUse[ x ] = pdFALSE;
	}
 
	/* Initialise the Rx descriptors. */
	for( x = 0; x < emacNUM_RX_DESCRIPTORS; x++ )
	{
		pxDescriptor = &( xRxDescriptors[ x ] );
		pxDescriptor->buf_p = &( xEthernetBuffers[ x ][ 0 ] );
 
		pxDescriptor->bufsize = UIP_BUFSIZE;
		pxDescriptor->size = 0;
		pxDescriptor->status = ACT;
		pxDescriptor->next = ( struct Descriptor * ) &xRxDescriptors[ x + 1 ];	
 
		/* Mark this buffer as in use. */
		ucBufferInUse[ x ] = pdTRUE;
	}
 
	/* The last descriptor points back to the start. */
	pxDescriptor->status |= DL;
	pxDescriptor->next = ( struct Descriptor * ) &xRxDescriptors[ 0 ];
 
	/* Initialise the Tx descriptors. */
	for( x = 0; x < emacNUM_TX_BUFFERS; x++ )
	{
		pxDescriptor = &( xTxDescriptors[ x ] );
 
		/* A buffer is not allocated to the Tx descriptor until a send is
		actually required. */
		pxDescriptor->buf_p = NULL;
 
		pxDescriptor->bufsize = UIP_BUFSIZE;
		pxDescriptor->size = 0;
		pxDescriptor->status = 0;
		pxDescriptor->next = ( struct Descriptor * ) &xTxDescriptors[ x + 1 ];	
	}
 
	/* The last descriptor points back to the start. */
	pxDescriptor->status |= DL;
	pxDescriptor->next = ( struct Descriptor * ) &( xTxDescriptors[ 0 ] );
 
	/* Use the first Rx descriptor to start with. */
	pxCurrentRxDesc = ( struct Descriptor * ) &( xRxDescriptors[ 0 ] );
}
/*-----------------------------------------------------------*/
 
static unsigned char *prvGetNextBuffer( void )
{
long x;
unsigned char *pucReturn = NULL;
unsigned long ulAttempts = 0;
 
	while( pucReturn == NULL )
	{
		/* Look through the buffers to find one that is not in use by
		anything else. */
		for( x = 0; x < emacNUM_BUFFERS; x++ )
		{
			if( ucBufferInUse[ x ] == pdFALSE )
			{
				ucBufferInUse[ x ] = pdTRUE;
				pucReturn = ( unsigned char * ) &( xEthernetBuffers[ x ][ 0 ] );
				break;
			}
		}
 
		/* Was a buffer found? */
		if( pucReturn == NULL )
		{
			ulAttempts++;
 
			if( ulAttempts >= emacBUFFER_WAIT_ATTEMPTS )
			{
				break;
			}
 
			/* Wait then look again. */
			vTaskDelay( emacBUFFER_WAIT_DELAY_ms );
		}
	}
 
	return pucReturn;
}
/*-----------------------------------------------------------*/
 
static void prvReturnBuffer( unsigned char *pucBuffer )
{
unsigned long ul;
 
	/* Return a buffer to the pool of free buffers. */
	for( ul = 0; ul < emacNUM_BUFFERS; ul++ )
	{
		if( &( xEthernetBuffers[ ul ][ 0 ] ) == ( void * ) pucBuffer )
		{
			ucBufferInUse[ ul ] = pdFALSE;
			break;
		}
	}
}
/*-----------------------------------------------------------*/
 
static void prvResetEverything( void )
{
	/* Temporary code just to see if this gets called.  This function has not
	been implemented. */
	portDISABLE_INTERRUPTS();
	for( ;; );
}
/*-----------------------------------------------------------*/
 
static unsigned long prvCheckRxFifoStatus( void )
{
unsigned long ulReturn = 0;
 
	if( ( pxCurrentRxDesc->status & ACT ) != 0 )
	{
		/* Current descriptor is still active. */
	}
	else if( ( pxCurrentRxDesc->status & FE ) != 0 )
	{
		/* Frame error.  Clear the error. */
		pxCurrentRxDesc->status &= ~( FP1 | FP0 | FE );
		pxCurrentRxDesc->status &= ~( RMAF | RRF | RTLF | RTSF | PRE | CERF );
		pxCurrentRxDesc->status |= ACT;
		pxCurrentRxDesc = pxCurrentRxDesc->next;
 
		if( EDMAC.EDRRR.LONG == 0x00000000UL )
		{
			/* Restart Ethernet if it has stopped. */
			EDMAC.EDRRR.LONG = 0x00000001UL;
		}	
	}
	else
	{
		/* The descriptor contains a frame.  Because of the size of the buffers
		the frame should always be complete. */
		if( ( pxCurrentRxDesc->status & FP0 ) == FP0 )
		{
			ulReturn = pxCurrentRxDesc->size;
		}
		else
		{
			/* Do not expect to get here. */
			prvResetEverything();
		}
	}
 
	return ulReturn;
}
/*-----------------------------------------------------------*/
 
static void prvResetMAC( void )
{
	/* Ensure the EtherC and EDMAC are enabled. */
	SYSTEM.MSTPCRB.BIT.MSTPB15 = 0;
	vTaskDelay( 100 / portTICK_RATE_MS );
 
	EDMAC.EDMR.BIT.SWR = 1;	
 
	/* Crude wait for reset to complete. */
	vTaskDelay( 500 / portTICK_RATE_MS );	
}
/*-----------------------------------------------------------*/
 
static void prvConfigureEtherCAndEDMAC( void )
{
	/* Initialisation code taken from Renesas example project. */
 
	/* TODO:    Check   bit 5   */
	ETHERC.ECSR.LONG = 0x00000037;				/* Clear all ETHERC statuS BFR, PSRTO, LCHNG, MPD, ICD */
 
	/* Set the EDMAC interrupt priority. */
	_IPR( _ETHER_EINT ) = configKERNEL_INTERRUPT_PRIORITY;
 
	/* TODO:    Check   bit 5   */
	/* Enable interrupts of interest only. */
	EDMAC.EESIPR.LONG = emacTX_END_INTERRUPT | emacRX_END_INTERRUPT;
	ETHERC.RFLR.LONG = 1518;					/* Ether payload is 1500+ CRC */
	ETHERC.IPGR.LONG = 0x00000014;				/* Intergap is 96-bit time */
 
	/* EDMAC */
	EDMAC.EESR.LONG = 0x47FF0F9F;				/* Clear all ETHERC and EDMAC status bits */
	#ifdef __RX_LITTLE_ENDIAN__
		EDMAC.EDMR.BIT.DE = 1;
	#endif
	EDMAC.RDLAR = ( void * ) pxCurrentRxDesc;	/* Initialaize Rx Descriptor List Address */
	EDMAC.TDLAR = ( void * ) &( xTxDescriptors[ 0 ] );	/* Initialaize Tx Descriptor List Address */
	EDMAC.TRSCER.LONG = 0x00000000;				/* Copy-back status is RFE & TFE only   */
	EDMAC.TFTR.LONG = 0x00000000;				/* Threshold of Tx_FIFO */
	EDMAC.FDR.LONG = 0x00000000;				/* Transmit fifo & receive fifo is 256 bytes */
	EDMAC.RMCR.LONG = 0x00000003;				/* Receive function is normal mode(continued) */
 
	/* Enable the interrupt... */
	_IEN( _ETHER_EINT ) = 1;	
}
/*-----------------------------------------------------------*/
 
void vEMAC_ISR_Handler( void )
{
unsigned long ul = EDMAC.EESR.LONG;
long lHigherPriorityTaskWoken = pdFALSE;
extern xSemaphoreHandle xEMACSemaphore;
static long ulTxEndInts = 0;
 
	/* Re-enabled interrupts. */
	__asm volatile( "SETPSW	I" );
 
	/* Has a Tx end occurred? */
	if( ul & emacTX_END_INTERRUPT )
	{
		++ulTxEndInts;
		if( ulTxEndInts >= 2 )
		{
			/* Only return the buffer to the pool once both Txes have completed. */
			prvReturnBuffer( ( void * ) xTxDescriptors[ 0 ].buf_p );
			ulTxEndInts = 0;
		}
		EDMAC.EESR.LONG = emacTX_END_INTERRUPT;
	}
 
	/* Has an Rx end occurred? */
	if( ul & emacRX_END_INTERRUPT )
	{
		/* Make sure the Ethernet task is not blocked waiting for a packet. */
		xSemaphoreGiveFromISR( xEMACSemaphore, &lHigherPriorityTaskWoken );
		portYIELD_FROM_ISR( lHigherPriorityTaskWoken );
		EDMAC.EESR.LONG = emacRX_END_INTERRUPT;
	}
}