/*
 * Play with interrupts
 */

#include	<asm-m68knommu/coldfire.h>
#include	<asm-m68knommu/m5249sim.h>

#include	<linux/signal.h>
#include	<linux/kernel.h>
#include	<linux/module.h> 

#include <linux/user.h>

/*
 * Direct trap on coldfire
 */

extern void myirc(int irq, void *dev_id, struct pt_regs *regs);

void myirq_wrapper( void)
{
	__asm__("
		.global	myirc
		myirc:
			rte
                        sub.l   #20, %sp
                        movem.l %d0-%d2/%a0-%a1, %sp@   /* Save registers */

			/* switch led state */
			move.l	#(0x80000000+0x4),%a0
			move.l	%a0@,%d0
			eor.l	#0x0800,%d0
			move.l	%d0,%a0@

			/* clear interrupts for GPIO7 */
			move.l	#(0x80000000+0xc0),%a0
			move.l	#0x080,%a0@

                        movem.l %sp@, %d0-%d2/%a0-%a1   /* Restore registers */
                        add.l   #20, %sp
                        rte
	");
}

/*
 *  Set up trap on irq 7 ( the button on the board )
 */

int main()
{
	int i;
	unsigned long j, k;

	j = 1<<11 ;

	k = *((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOFUNC));
	printf(" func = %x",k);
	*((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOFUNC)) = k|j;
	k = *((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOFUNC));
	printf(" func = %x\n",k);
	
	k = *((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOENABLE));
	printf(" enable = %x",k);
	*((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOENABLE)) = k|j;
	k = *((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOENABLE));
	printf(" enable = %x\n",k);

	k = *((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOINTSTAT ));
	printf("\n gpio interupt status = %x",k);
	k = *((volatile unsigned long *)(MCF_MBAR2 + MCFSIM2_GPIOINTENABLE ));
	printf("\n gpio interupt enable = %x\n",k);
	
	/* Save interrupt handler in k */
	k = *((unsigned long *) (4*0xa7));

	/* reconfigure interrupt */
	*((unsigned long *) (4*0xa7)) = (unsigned long) myirc;
	
	sleep( 120 );
	
	/* restore interrupt handler */
	*((unsigned long *) (4*0xa7)) = k;

	return 0;
}