#ifndef NULL
#define NULL ((void *)(0))
#endif

typedef unsigned short u_short;
typedef unsigned long u_long;

#define H0x1f801070 (*(u_short*)(0x1f801070))
#define IntrMask    (*(u_long *)(0x1f801074))
#define DmaMask     (*(u_long *)(0x1f8010f4))
#define H_count     (*(u_long *)(0x1f801110))
#define H0x1f801114 (*(u_long *)(0x1f801114))

typedef struct {
	char *RCSid;			/* 00 */
	void (*dmaIntr)();		/* 04 */
	void (*setIntr)();		/* 08 */
	void (*startIntr)(void);	/* 0c */
	void (*stopIntr)(void);		/* 10 */
	void (*vsyncIntr)();		/* 14 */
} INTR_CB_T;

setIntr(int index, u_long callback);
void startIntr(void);
void stopIntr(void);

static INTR_CB_T intrCallbacks = {
	"$Id: intr.c,v 1.68 1995/07/11 08:45:01 suzu Exp $",
	NULL,
	setIntr,
	startIntr,
	stopIntr,
	NULL
};

static INTR_CB_T *intrCB = &intrCallbacks;

/* memclr(*ptr, size) -> size in WORDS */

/* 0x8002ec34 */
void ResetCallback(void)
{
	intrCB->startIntr();

}

/* 0x8002ec64 */
void InterruptCallback(index, callback)
{
	intrCB->setIntr(index, callback);
}

/* 0x8002ec94 */
void DMACallback(index, callback)
{
	intrCB->dmaIntr(index, callback);
}

/* 0x800????? */
void VSyncCallback(callback)
{
	intrCB->vsyncIntr(0, callback);
}

/* 0x8002ecc4 */
void VSyncCallbacks(index, callback)
{
	intrCB->vsyncIntr(index, callback);
}

/* 0x8002ecf4 */
void StopCallback()
{
	intrCB->stopIntr();
}

/* 0x8002ed24 */
int CheckCallback()
{
	return intrData.cback;
}

/* 0x8002ed38 */
int GetIntrMask()
{
	return IntrMask;
}

/* 0x8002ed50 */
int SetIntrMask(int mask)
{
	int old;

	old = IntrMask;
	IntrMask = mask;

	return old;

}

/* 0x8002ed6c */
void startIntr(void)
{
	if (!intrData.flag) {
		EnterCriticalSection();
	}
	memclr(&intrData, 25);
	if (setjmp(&intrData.jmp)) {
		trapIntr();
	}
	intrData.flag = 1;
	intrCB->vsyncIntr = startIntrVSync();
	intrCB->dmaIntr = startIntrDMA();
	_96_remove();
	intrData.jmp[JB_SP] = &_0x8005aaec;	/* rescan */
	HookEntryInt(&intrData.jmp);
	ExitCriticalSection();
}

/* 0x8002ee2c */
trapIntr()
{
	intrData.callback = 1;
	while (s = (IntrMask & (intrData.mask & H0x1f801070))) {
	}
}

/* 0x8002effc */
setIntr(int index, u_long callback)
{
	u_short mask;

	if (callback == intrData.callback[index] || !intrData.flag) {
		return intrData.callback[index];
	}
	mask = IntrMask;
	IntrMask = 0;
	if (callback) {
		intrData.callback[index] = callback;
		mask |= (1 << index);
		intrData.mask = (1 << index) | intrData.mask;
	} else {
		intrData.callback[index] = NULL;
		mask &= ~(1 << index);
		intrData.mask = ~(1 << index) & intrData.mask;
	}
	if (index == 4) {
		ChangeClearRCnt(0, (callback == NULL));
	}
	if (index == 5) {
		ChangeClearRCnt(1, (callback == NULL));
	}
	if (index == 6) {
		ChangeClearRCnt(2, (callback == NULL));
	}
	IntrMask = mask;

	return intrData.callback[index];
}

/* 0x8002f12c */
void stopIntr(void)
{
	EnterCriticalSection();
	memclr(&intrData, 25);
	H0x1f801070 = 0;			/* u_short */
	IntrMask = H0x1f801070;			/* u_short */
	stopIntrVSync();
	stopIntrDMA();
	ResetEntryInt();
	ExitCriticalSection();
}

/* 0x8002f228 */
void startIntrDMA(void)
{
	memclr(&dmaData, 9);
	DmaMask = 0;
	InterruptCallback(3, trapIntrDMA);
	dmaData.flag = 1;

	return setIntrDMA;
}

/* 0x8002f28c */
void stopIntrDMA(void)
{
	dmaData.flag = 0;
	memclr(&dmaData, 9);
	DmaMask = 0;
	InterruptCallback(3, NULL);
}

/* 0x8002f2d4 */
trapIntrDMA()
{
	while (s = (IntrMask >> 24) & 127) {
		/* Real mess, i'll do it later */
	}
}


/* 0x8002f438 */
setIntrDMA(index, callback)
{
	int old;

	if (callback == dmaData.callback[index] || !dmaData.flag) {
		return dmaData.callback[index];
	}
	old = SetIntrMask(0);
	if (callback) {
		dmaData.callback[index] = callback;
		DmaMask = (DmaMask & 0x00ffffff) | ((1 << (index + 16)) | 0x00800000);
	} else {
		dmaData.callback[index] = NULL;
		DmaMask = ((DmaMask & 0x00ffffff) | 0x00800000) & ~(1 << (index + 16));
	}
	SetIntrMask(old);

	return dmaData.callback[index];
}

/* 0x8002f684 */
void startIntrVSync(void)
{
	H0x1f801114 = 0x0107;
	ChangeClearPad(0);
	ChangeClearRCnt(3, 0);
	memclr(&vsyncData, 2);
	InterruptCallback(0, trapIntrVSync);
	vsyncData.flag = 1;

	return setIntrVSync;
}

/* 0x8002f6fc */
stopIntrVSync()
{
	vsyncData.flag = 0;
	memclr(&vsyncData, 2);
	InterruptCallback(0, NULL);
}

/* 0x8002f734 */
trapIntrVSync()
{
	Vcount++;
	if (vsyncData.intr) {
		return (*vsyncData.intr)();
	}


	return Vcount;
}

/* 0x8002f780 */
setIntrVSync(vsync)
{
	int old;

	if (vsyncData.flag && vsync != vsyncData.intr) {
		old = vsyncData.intr;
		vsyncData.intr = vsync;
	}

	return old;
}

/* 0x8002f7e4 */
VSync(count)
{
	s0 = H0x1f801814;		/* latch read ? */
	s1 = H_count - Hcount;
	if (count < 0) {
		return Vcount;
	}
	if (count == 1) {
		return s1;
	}
	v_wait( count > 0 ? (oldVcount - 1) + count : oldVcount,
		count > 0 ? 0 : count - 1);
	s0 = H0x1f801814;
	v_wait(Vcount - 1, 1);
	if (s0 & 0x00080000 && s0 ^ H0x1f801814) {	/* rescan */
		while ((s0 ^ H0x1f801814) & 0x80000000) ;
	}
	oldVcount = Vcount;
	Hcount = H_count;

	return s1;
}

v_wait(a0, a1)
{
	a1 <<= 15;
	while (Vcount < a0) {
		a1--;
		if (a1 == -1) {
			puts("VSync: timeout\n");
			ChangeClearPad(0);
			ChangeClearRCnt(3, 0);
			break;
		}
	}
}