Demo/ARM7_LPC2138_Rowley/mainISR.c

/*
	FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 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.

    ***************************************************************************
    ***************************************************************************
    *                                                                         *
    * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *
	*                                                                         *
	* This is a concise, step by step, 'hands on' guide that describes both   *
	* general multitasking concepts and FreeRTOS specifics. It presents and   *
	* explains numerous examples that are written using the FreeRTOS API.     *
	* Full source code for all the examples is provided in an accompanying    *
	* .zip file.                                                              *
    *                                                                         *
    ***************************************************************************
    ***************************************************************************

	Please ensure to read the configuration and relevant port sections of the
	online documentation.

	http://www.FreeRTOS.org - Documentation, latest information, license and 
	contact details.

	http://www.SafeRTOS.com - A version that is certified for use in safety 
	critical systems.

	http://www.OpenRTOS.com - Commercial support, development, porting, 
	licensing and training services.
*/
#include "FreeRTOS.h"
#include "semphr.h"

#define isrCLEAR_EINT_1 2

/*
 * Interrupt routine that simply wakes vButtonHandlerTask on each interrupt 
 * generated by a push of the built in button.  The wrapper takes care of
 * the ISR entry.  This then calls the actual handler function to perform
 * the work.  This work should not be done in the wrapper itself unless
 * you are absolutely sure that no stack space is used.
 */
void vButtonISRWrapper( void ) __attribute__ ((naked));
void vButtonHandler( void );

void vButtonHandler( void )
{
extern xSemaphoreHandle xButtonSemaphore;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	xSemaphoreGiveFromISR( xButtonSemaphore, &xHigherPriorityTaskWoken );

	if( xHigherPriorityTaskWoken )
	{
		/* We have woken a task.  Calling "yield from ISR" here will ensure
		the interrupt returns to the woken task if it has a priority higher
		than the interrupted task. */
		portYIELD_FROM_ISR();
	}

    EXTINT = isrCLEAR_EINT_1;
    VICVectAddr = 0;
}
/*-----------------------------------------------------------*/

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

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

	/* Restore the context of whichever task is going to run once the interrupt
	completes. */
	portRESTORE_CONTEXT();
}