int0.c

开发板外设接口实验（1～7）

/*
 *	int0.c   -  int0 api & driver 
 *	
 *	Author: 	li ming <[e-mail]>
 *	Date:		2008-4-16
 *	Copyleft:	http://www.lumit.org
 */
 
#include "int0.h"
#include "irq.h"

/*  
; hardware connection
; PIO8	(gpio)
; 1  	(int0)
; so output value = 0x00000100 = (0b0000 0000  0000 0000  0000 0001  0000 0000)
*/

/* define the relative gpio register */
#define SYSCFG      0x03FF0000
#define IOPMOD		(*((volatile unsigned *)(SYSCFG+0x5000)))
#define IOPDATA		(*((volatile unsigned *)(SYSCFG+0x5008)))
#define IOPCON		(*((volatile unsigned *)(SYSCFG+0x5004)))

#define INT0_IO_RISING_EDGE				(0x01)
#define INT0_MASK						(1 << 0)
#define INT0_IO_ENABLE					(1<<4)

/* set int0 related gpio */
int int0_init(void)
{
	// External interrupt 0 source number is 0
	// set gpio's direction: set IOPMOD register mode bit to 0 = input
	IOPMOD = IOPMOD & (~0x00000100);
	
	return 0;
}

int int0_is_down(void)
{ 
	if(IOPDATA & (1 << 8))
		return 1;	
	
	return 0;
} 

int int0_is_up(void)
{ 
	if(IOPDATA & (1 << 8))
		return 0;	
	
	return 1;
} 

static void (*int0_irq_hooker)(void) = 0;

void int0_install_irq_hooker( void (*hooker)(void) )
{
	int0_irq_hooker = hooker;
}

void int0_irq_handler(void)
{
		/* reset the tdata */		
		if( int0_irq_hooker )
			int0_irq_hooker();
			
		return;
}

int int0_enable_irq(void)
{
	/* Set interrupt evoke mode */
	IOPCON |= INT0_IO_RISING_EDGE;

	/* register irq no 0 to a handler */
	request_irq(0, int0_irq_handler);	
		
	/* Enable interrupt */
	IOPCON 	|= INT0_IO_ENABLE;

	
	return 0;
}

int status = 0;
	 
int int0_test(void)
{
	int0_init();
	
	while(1)
	{
		status = int0_is_up();
		status = int0_is_down();
	}	
	return status;
}