Demo/lwIP_Demo_Rowley_ARM7/EMAC/SAM7_EMAC_ISR.c

/*
	FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd.

	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
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	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.

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	with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
	Temple Place, Suite 330, Boston, MA  02111-1307  USA.


	***************************************************************************
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	Please ensure to read the configuration and relevant port sections of the
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*/


#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
#include "SAM7_EMAC.h"
#include "AT91SAM7X256.h"

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

/* The semaphore used to signal the arrival of new data to the interface
task. */
static xSemaphoreHandle xSemaphore = NULL;

/* The interrupt entry point is naked so we can control the context saving. */
void vEMACISR_Wrapper( void ) __attribute__((naked));

/* The interrupt handler function must be separate from the entry function
to ensure the correct stack frame is set up. */
void vEMACISR_Handler( void );

/*-----------------------------------------------------------*/
/*
 * The EMAC ISR.  Handles both Tx and Rx complete interrupts.
 */
void vEMACISR_Handler( void )
{
volatile unsigned portLONG ulIntStatus, ulEventStatus;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
extern void vClearEMACTxBuffer( void );

	/* Find the cause of the interrupt. */
	ulIntStatus = AT91C_BASE_EMAC->EMAC_ISR;
	ulEventStatus = AT91C_BASE_EMAC->EMAC_RSR;

	if( ( ulIntStatus & AT91C_EMAC_RCOMP ) || ( ulEventStatus & AT91C_EMAC_REC ) )
	{
		/* A frame has been received, signal the lwIP task so it can process
		the Rx descriptors. */
		xSemaphoreGiveFromISR( xSemaphore, &xHigherPriorityTaskWoken );
		AT91C_BASE_EMAC->EMAC_RSR = AT91C_EMAC_REC;
	}

	if( ulIntStatus & AT91C_EMAC_TCOMP )
	{
		/* A frame has been transmitted.  Mark all the buffers used by the
		frame just transmitted as free again. */
		vClearEMACTxBuffer();
		AT91C_BASE_EMAC->EMAC_TSR = AT91C_EMAC_COMP;
	}

	/* Clear the interrupt. */
	AT91C_BASE_AIC->AIC_EOICR = 0;

	/* If a task was woken by either a frame being received then we may need to 
	switch to another task.  If the unblocked task was of higher priority then
	the interrupted task it will then execute immediately that the ISR
	completes. */
	if( xHigherPriorityTaskWoken )
	{
		portYIELD_FROM_ISR();
	}
}
/*-----------------------------------------------------------*/

void  vEMACISR_Wrapper( void )
{
	/* Save the context of the interrupted task. */
	portSAVE_CONTEXT();

	/* Call the handler to do the work.  This must be a separate
	function to ensure the stack frame is set up correctly. */
	vEMACISR_Handler();

	/* Restore the context of whichever task will execute next. */
	portRESTORE_CONTEXT();
}
/*-----------------------------------------------------------*/

void vPassEMACSemaphore( xSemaphoreHandle xCreatedSemaphore )
{
	/* Simply store the semaphore that should be used by the ISR. */
	xSemaphore = xCreatedSemaphore;
}