sam7_emac_isr.c

FreeRTOS - V5.1.1 Last Update: Nov 20 2008 http://sourceforge.net/projects/freertos/

/*
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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;
}