[mirror_ubuntu-jammy-kernel.git] / arch / m68k / mac / via.c

/*
 *	6522 Versatile Interface Adapter (VIA)
 *
 *	There are two of these on the Mac II. Some IRQs are vectored
 *	via them as are assorted bits and bobs - eg RTC, ADB.
 *
 * CSA: Motorola seems to have removed documentation on the 6522 from
 * their web site; try
 *     http://nerini.drf.com/vectrex/other/text/chips/6522/
 *     http://www.zymurgy.net/classic/vic20/vicdet1.htm
 * and
 *     http://193.23.168.87/mikro_laborversuche/via_iobaustein/via6522_1.html
 * for info.  A full-text web search on 6522 AND VIA will probably also
 * net some usefulness. <cananian@alumni.princeton.edu> 20apr1999
 *
 * Additional data is here (the SY6522 was used in the Mac II etc):
 *     http://www.6502.org/documents/datasheets/synertek/synertek_sy6522.pdf
 *     http://www.6502.org/documents/datasheets/synertek/synertek_sy6522_programming_reference.pdf
 *
 * PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
 * by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ide.h>

#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>
#include <asm/mac_psc.h>

volatile __u8 *via1, *via2;
#if 0
/* See note in mac_via.h about how this is possibly not useful */
volatile long *via_memory_bogon=(long *)&via_memory_bogon;
#endif
int rbv_present, via_alt_mapping;
__u8 rbv_clear;

/*
 * Globals for accessing the VIA chip registers without having to
 * check if we're hitting a real VIA or an RBV. Normally you could
 * just hit the combined register (ie, vIER|rIER) but that seems to
 * break on AV Macs...probably because they actually decode more than
 * eight address bits. Why can't Apple engineers at least be
 * _consistently_ lazy?                          - 1999-05-21 (jmt)
 */

static int gIER,gIFR,gBufA,gBufB;

/*
 * Timer defs.
 */

#define TICK_SIZE		10000
#define MAC_CLOCK_TICK		(783300/HZ)		/* ticks per HZ */
#define MAC_CLOCK_LOW		(MAC_CLOCK_TICK&0xFF)
#define MAC_CLOCK_HIGH		(MAC_CLOCK_TICK>>8)

/* To disable a NuBus slot on Quadras we make the slot IRQ lines outputs, set
 * high. On RBV we just use the slot interrupt enable register. On Macs with
 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
 * because closing one of those drivers can mask all of the NuBus interrupts.
 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
 * possible to get interrupts from cards that MacOS or the ROM has configured
 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
 */
static u8 nubus_disabled;

void via_debug_dump(void);
irqreturn_t via1_irq(int, void *);
irqreturn_t via2_irq(int, void *);
irqreturn_t via_nubus_irq(int, void *);
void via_irq_enable(int irq);
void via_irq_disable(int irq);
void via_irq_clear(int irq);

extern irqreturn_t mac_scc_dispatch(int, void *);
extern int oss_present;

/*
 * Initialize the VIAs
 *
 * First we figure out where they actually _are_ as well as what type of
 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
 * Then we pretty much clear them out and disable all IRQ sources.
 *
 * Note: the OSS is actually "detected" here and not in oss_init(). It just
 *	 seems more logical to do it here since via_init() needs to know
 *	 these things anyways.
 */

void __init via_init(void)
{
	switch(macintosh_config->via_type) {

		/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */

		case MAC_VIA_IIci:
			via1 = (void *) VIA1_BASE;
			if (macintosh_config->ident == MAC_MODEL_IIFX) {
				via2 = NULL;
				rbv_present = 0;
				oss_present = 1;
			} else {
				via2 = (void *) RBV_BASE;
				rbv_present = 1;
				oss_present = 0;
			}
			if (macintosh_config->ident == MAC_MODEL_LCIII) {
				rbv_clear = 0x00;
			} else {
				/* on most RBVs (& unlike the VIAs), you   */
				/* need to set bit 7 when you write to IFR */
				/* in order for your clear to occur.       */
				rbv_clear = 0x80;
			}
			gIER = rIER;
			gIFR = rIFR;
			gBufA = rSIFR;
			gBufB = rBufB;
			break;

		/* Quadra and early MacIIs agree on the VIA locations */

		case MAC_VIA_QUADRA:
		case MAC_VIA_II:
			via1 = (void *) VIA1_BASE;
			via2 = (void *) VIA2_BASE;
			rbv_present = 0;
			oss_present = 0;
			rbv_clear = 0x00;
			gIER = vIER;
			gIFR = vIFR;
			gBufA = vBufA;
			gBufB = vBufB;
			break;
		default:
			panic("UNKNOWN VIA TYPE");
	}

	printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);

	printk(KERN_INFO "VIA2 at %p is ", via2);
	if (rbv_present) {
		printk("an RBV\n");
	} else if (oss_present) {
		printk("an OSS\n");
	} else {
		printk("a 6522 or clone\n");
	}

#ifdef DEBUG_VIA
	via_debug_dump();
#endif

	/*
	 * Shut down all IRQ sources, reset the timers, and
	 * kill the timer latch on VIA1.
	 */

	via1[vIER] = 0x7F;
	via1[vIFR] = 0x7F;
	via1[vT1LL] = 0;
	via1[vT1LH] = 0;
	via1[vT1CL] = 0;
	via1[vT1CH] = 0;
	via1[vT2CL] = 0;
	via1[vT2CH] = 0;
	via1[vACR] &= 0x3F;
	via1[vACR] &= ~0x03; /* disable port A & B latches */

	/*
	 * SE/30: disable video IRQ
	 * XXX: testing for SE/30 VBL
	 */

	if (macintosh_config->ident == MAC_MODEL_SE30) {
		via1[vDirB] |= 0x40;
		via1[vBufB] |= 0x40;
	}

	/*
	 * Set the RTC bits to a known state: all lines to outputs and
	 * RTC disabled (yes that's 0 to enable and 1 to disable).
	 */

	via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
	via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);

	/* Everything below this point is VIA2/RBV only... */

	if (oss_present) return;

#if 1
	/* Some machines support an alternate IRQ mapping that spreads  */
	/* Ethernet and Sound out to their own autolevel IRQs and moves */
	/* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
	/* that the IIfx emulates this alternate mapping using the OSS. */

	switch(macintosh_config->ident) {
		case MAC_MODEL_P475:
		case MAC_MODEL_P475F:
		case MAC_MODEL_P575:
		case MAC_MODEL_Q605:
		case MAC_MODEL_Q605_ACC:
		case MAC_MODEL_C610:
		case MAC_MODEL_Q610:
		case MAC_MODEL_Q630:
		case MAC_MODEL_C650:
		case MAC_MODEL_Q650:
		case MAC_MODEL_Q700:
		case MAC_MODEL_Q800:
		case MAC_MODEL_Q900:
		case MAC_MODEL_Q950:
			via_alt_mapping = 1;
			via1[vDirB] |= 0x40;
			via1[vBufB] &= ~0x40;
			break;
		default:
			via_alt_mapping = 0;
			break;
	}
#else
	via_alt_mapping = 0;
#endif

	/*
	 * Now initialize VIA2. For RBV we just kill all interrupts;
	 * for a regular VIA we also reset the timers and stuff.
	 */

	via2[gIER] = 0x7F;
	via2[gIFR] = 0x7F | rbv_clear;
	if (!rbv_present) {
		via2[vT1LL] = 0;
		via2[vT1LH] = 0;
		via2[vT1CL] = 0;
		via2[vT1CH] = 0;
		via2[vT2CL] = 0;
		via2[vT2CH] = 0;
		via2[vACR] &= 0x3F;
		via2[vACR] &= ~0x03; /* disable port A & B latches */
	}

	/*
	 * Set vPCR for SCSI interrupts (but not on RBV)
	 */
	if (!rbv_present) {
		if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
			/* CB2 (IRQ) indep. input, positive edge */
			/* CA2 (DRQ) indep. input, positive edge */
			via2[vPCR] = 0x66;
		} else {
			/* CB2 (IRQ) indep. input, negative edge */
			/* CA2 (DRQ) indep. input, negative edge */
			via2[vPCR] = 0x22;
		}
	}
}

/*
 * Start the 100 Hz clock
 */

void __init via_init_clock(irq_handler_t func)
{
	via1[vACR] |= 0x40;
	via1[vT1LL] = MAC_CLOCK_LOW;
	via1[vT1LH] = MAC_CLOCK_HIGH;
	via1[vT1CL] = MAC_CLOCK_LOW;
	via1[vT1CH] = MAC_CLOCK_HIGH;

	request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
}

/*
 * Register the interrupt dispatchers for VIA or RBV machines only.
 */

void __init via_register_interrupts(void)
{
	if (via_alt_mapping) {
		request_irq(IRQ_AUTO_1, via1_irq,
				IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
				(void *) via1);
		request_irq(IRQ_AUTO_6, via1_irq,
				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
				(void *) via1);
	} else {
		request_irq(IRQ_AUTO_1, via1_irq,
				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
				(void *) via1);
	}
	request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
			"via2", (void *) via2);
	if (!psc_present) {
		request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
				"scc", mac_scc_dispatch);
	}
	request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
			"nubus", (void *) via2);
}

/*
 * Debugging dump, used in various places to see what's going on.
 */

void via_debug_dump(void)
{
	printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
		(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
	printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
		(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
	if (oss_present) {
		printk(KERN_DEBUG "VIA2: <OSS>\n");
	} else if (rbv_present) {
		printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
			(uint) via2[rIFR], (uint) via2[rIER]);
		printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
			(uint) via2[rSIFR], (uint) via2[rSIER]);
	} else {
		printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
			(uint) via2[vDirA], (uint) via2[vDirB],
			(uint) via2[vACR]);
		printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
			(uint) via2[vPCR],
			(uint) via2[vIFR], (uint) via2[vIER]);
	}
}

/*
 * This is always executed with interrupts disabled.
 *
 * TBI: get time offset between scheduling timer ticks
 */

unsigned long mac_gettimeoffset (void)
{
	unsigned long ticks, offset = 0;

	/* read VIA1 timer 2 current value */
	ticks = via1[vT1CL] | (via1[vT1CH] << 8);
	/* The probability of underflow is less than 2% */
	if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
		/* Check for pending timer interrupt in VIA1 IFR */
		if (via1[vIFR] & 0x40) offset = TICK_SIZE;

	ticks = MAC_CLOCK_TICK - ticks;
	ticks = ticks * 10000L / MAC_CLOCK_TICK;

	return ticks + offset;
}

/*
 * Flush the L2 cache on Macs that have it by flipping
 * the system into 24-bit mode for an instant.
 */

void via_flush_cache(void)
{
	via2[gBufB] &= ~VIA2B_vMode32;
	via2[gBufB] |= VIA2B_vMode32;
}

/*
 * Return the status of the L2 cache on a IIci
 */

int via_get_cache_disable(void)
{
	/* Safeguard against being called accidentally */
	if (!via2) {
		printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
		return 1;
	}

	return (int) via2[gBufB] & VIA2B_vCDis;
}

/*
 * Initialize VIA2 for Nubus access
 */

void __init via_nubus_init(void)
{
	/* unlock nubus transactions */

	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
	    (macintosh_config->adb_type != MAC_ADB_PB2)) {
		/* set the line to be an output on non-RBV machines */
		if (!rbv_present)
			via2[vDirB] |= 0x02;

		/* this seems to be an ADB bit on PMU machines */
		/* according to MkLinux.  -- jmt               */
		via2[gBufB] |= 0x02;
	}

	/* Disable all the slot interrupts (where possible). */

	switch (macintosh_config->via_type) {
	case MAC_VIA_II:
		/* Just make the port A lines inputs. */
		switch(macintosh_config->ident) {
		case MAC_MODEL_II:
		case MAC_MODEL_IIX:
		case MAC_MODEL_IICX:
		case MAC_MODEL_SE30:
			/* The top two bits are RAM size outputs. */
			via2[vDirA] &= 0xC0;
			break;
		default:
			via2[vDirA] &= 0x80;
		}
		break;
	case MAC_VIA_IIci:
		/* RBV. Disable all the slot interrupts. SIER works like IER. */
		via2[rSIER] = 0x7F;
		break;
	case MAC_VIA_QUADRA:
		/* Disable the inactive slot interrupts by making those lines outputs. */
		if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
		    (macintosh_config->adb_type != MAC_ADB_PB2)) {
			via2[vBufA] |= 0x7F;
			via2[vDirA] |= 0x7F;
		}
		break;
	}
}

/*
 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
 * via6522.c :-), disable/pending masks added.
 */

irqreturn_t via1_irq(int irq, void *dev_id)
{
	int irq_num;
	unsigned char irq_bit, events;

	events = via1[vIFR] & via1[vIER] & 0x7F;
	if (!events)
		return IRQ_NONE;

	irq_num = VIA1_SOURCE_BASE;
	irq_bit = 1;
	do {
		if (events & irq_bit) {
			via1[vIFR] = irq_bit;
			m68k_handle_int(irq_num);
		}
		++irq_num;
		irq_bit <<= 1;
	} while (events >= irq_bit);

#if 0 /* freakin' pmu is doing weird stuff */
	if (!oss_present) {
		/* This (still) seems to be necessary to get IDE
		   working.  However, if you enable VBL interrupts,
		   you're screwed... */
		/* FIXME: should we check the SLOTIRQ bit before
                   pulling this stunt? */
		/* No, it won't be set. that's why we're doing this. */
		via_irq_disable(IRQ_MAC_NUBUS);
		via_irq_clear(IRQ_MAC_NUBUS);
		m68k_handle_int(IRQ_MAC_NUBUS);
		via_irq_enable(IRQ_MAC_NUBUS);
	}
#endif
	return IRQ_HANDLED;
}

irqreturn_t via2_irq(int irq, void *dev_id)
{
	int irq_num;
	unsigned char irq_bit, events;

	events = via2[gIFR] & via2[gIER] & 0x7F;
	if (!events)
		return IRQ_NONE;

	irq_num = VIA2_SOURCE_BASE;
	irq_bit = 1;
	do {
		if (events & irq_bit) {
			via2[gIFR] = irq_bit | rbv_clear;
			m68k_handle_int(irq_num);
		}
		++irq_num;
		irq_bit <<= 1;
	} while (events >= irq_bit);
	return IRQ_HANDLED;
}

/*
 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
 * VIA2 dispatcher as a fast interrupt handler.
 */

irqreturn_t via_nubus_irq(int irq, void *dev_id)
{
	int slot_irq;
	unsigned char slot_bit, events;

	events = ~via2[gBufA] & 0x7F;
	if (rbv_present)
		events &= via2[rSIER];
	else
		events &= ~via2[vDirA];
	if (!events)
		return IRQ_NONE;

	do {
		slot_irq = IRQ_NUBUS_F;
		slot_bit = 0x40;
		do {
			if (events & slot_bit) {
				events &= ~slot_bit;
				m68k_handle_int(slot_irq);
			}
			--slot_irq;
			slot_bit >>= 1;
		} while (events);

 		/* clear the CA1 interrupt and make certain there's no more. */
		via2[gIFR] = 0x02 | rbv_clear;
		events = ~via2[gBufA] & 0x7F;
		if (rbv_present)
			events &= via2[rSIER];
		else
			events &= ~via2[vDirA];
	} while (events);
	return IRQ_HANDLED;
}

void via_irq_enable(int irq) {
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);

#ifdef DEBUG_IRQUSE
	printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
#endif

	if (irq_src == 1) {
		via1[vIER] = IER_SET_BIT(irq_idx);
	} else if (irq_src == 2) {
		if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
			via2[gIER] = IER_SET_BIT(irq_idx);
	} else if (irq_src == 7) {
		switch (macintosh_config->via_type) {
		case MAC_VIA_II:
			nubus_disabled &= ~(1 << irq_idx);
			/* Enable the CA1 interrupt when no slot is disabled. */
			if (!nubus_disabled)
				via2[gIER] = IER_SET_BIT(1);
			break;
		case MAC_VIA_IIci:
			/* On RBV, enable the slot interrupt.
			 * SIER works like IER.
			 */
			via2[rSIER] = IER_SET_BIT(irq_idx);
			break;
		case MAC_VIA_QUADRA:
			/* Make the port A line an input to enable the slot irq.
			 * But not on PowerBooks, that's ADB.
			 */
			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
			    (macintosh_config->adb_type != MAC_ADB_PB2))
				via2[vDirA] &= ~(1 << irq_idx);
			break;
		}
	}
}

void via_irq_disable(int irq) {
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);

#ifdef DEBUG_IRQUSE
	printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
#endif

	if (irq_src == 1) {
		via1[vIER] = IER_CLR_BIT(irq_idx);
	} else if (irq_src == 2) {
		via2[gIER] = IER_CLR_BIT(irq_idx);
	} else if (irq_src == 7) {
		switch (macintosh_config->via_type) {
		case MAC_VIA_II:
			nubus_disabled |= 1 << irq_idx;
			if (nubus_disabled)
				via2[gIER] = IER_CLR_BIT(1);
			break;
		case MAC_VIA_IIci:
			via2[rSIER] = IER_CLR_BIT(irq_idx);
			break;
		case MAC_VIA_QUADRA:
			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
			    (macintosh_config->adb_type != MAC_ADB_PB2))
				via2[vDirA] |= 1 << irq_idx;
			break;
		}
	}
}

void via_irq_clear(int irq) {
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);
	int irq_bit	= 1 << irq_idx;

	if (irq_src == 1) {
		via1[vIFR] = irq_bit;
	} else if (irq_src == 2) {
		via2[gIFR] = irq_bit | rbv_clear;
	} else if (irq_src == 7) {
		/* FIXME: There is no way to clear an individual nubus slot
		 * IRQ flag, other than getting the device to do it.
		 */
	}
}

/*
 * Returns nonzero if an interrupt is pending on the given
 * VIA/IRQ combination.
 */

int via_irq_pending(int irq)
{
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);
	int irq_bit	= 1 << irq_idx;

	if (irq_src == 1) {
		return via1[vIFR] & irq_bit;
	} else if (irq_src == 2) {
		return via2[gIFR] & irq_bit;
	} else if (irq_src == 7) {
		/* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
		return ~via2[gBufA] & irq_bit;
	}
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* 6522 Versatile Interface Adapter (VIA)
	3	*
0c79cf6a	4	* There are two of these on the Mac II. Some IRQs are vectored
1da177e4 LT	5	* via them as are assorted bits and bobs - eg RTC, ADB.
	6	*
	7	* CSA: Motorola seems to have removed documentation on the 6522 from
	8	* their web site; try
	9	* http://nerini.drf.com/vectrex/other/text/chips/6522/
	10	* http://www.zymurgy.net/classic/vic20/vicdet1.htm
	11	* and
	12	* http://193.23.168.87/mikro_laborversuche/via_iobaustein/via6522_1.html
	13	* for info. A full-text web search on 6522 AND VIA will probably also
	14	* net some usefulness. <cananian@alumni.princeton.edu> 20apr1999
	15	*
67dfb153 FT	16	* Additional data is here (the SY6522 was used in the Mac II etc):
	17	* http://www.6502.org/documents/datasheets/synertek/synertek_sy6522.pdf
	18	* http://www.6502.org/documents/datasheets/synertek/synertek_sy6522_programming_reference.pdf
	19	*
1da177e4 LT	20	* PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
	21	* by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
	22	*
	23	*/
	24
	25	#include <linux/types.h>
	26	#include <linux/kernel.h>
	27	#include <linux/mm.h>
	28	#include <linux/delay.h>
	29	#include <linux/init.h>
	30	#include <linux/ide.h>
	31
1da177e4 LT	32	#include <asm/bootinfo.h>
	33	#include <asm/macintosh.h>
	34	#include <asm/macints.h>
	35	#include <asm/machw.h>
	36	#include <asm/mac_via.h>
	37	#include <asm/mac_psc.h>
	38
	39	volatile __u8 via1, via2;
	40	#if 0
	41	/* See note in mac_via.h about how this is possibly not useful */
	42	volatile long via_memory_bogon=(long )&via_memory_bogon;
	43	#endif
67dfb153	44	int rbv_present, via_alt_mapping;
1da177e4 LT	45	__u8 rbv_clear;
	46
	47	/*
	48	* Globals for accessing the VIA chip registers without having to
	49	* check if we're hitting a real VIA or an RBV. Normally you could
	50	* just hit the combined register (ie, vIER\|rIER) but that seems to
	51	* break on AV Macs...probably because they actually decode more than
	52	* eight address bits. Why can't Apple engineers at least be
	53	* _consistently_ lazy? - 1999-05-21 (jmt)
	54	*/
	55
	56	static int gIER,gIFR,gBufA,gBufB;
	57
	58	/*
	59	* Timer defs.
	60	*/
	61
	62	#define TICK_SIZE 10000
	63	#define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
	64	#define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
	65	#define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
	66
cd713ddc FT	67	/* To disable a NuBus slot on Quadras we make the slot IRQ lines outputs, set
	68	* high. On RBV we just use the slot interrupt enable register. On Macs with
	69	* genuine VIA chips we must use nubus_disabled to keep track of disabled slot
	70	* interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
	71	* or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
	72	* So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
	73	* because closing one of those drivers can mask all of the NuBus interrupts.
	74	* Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
	75	* possible to get interrupts from cards that MacOS or the ROM has configured
	76	* but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
	77	* Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
	78	*/
	79	static u8 nubus_disabled;
1da177e4 LT	80
1da177e4 LT	81	void via_debug_dump(void);
2850bc27 AV	82	irqreturn_t via1_irq(int, void *);
	83	irqreturn_t via2_irq(int, void *);
	84	irqreturn_t via_nubus_irq(int, void *);
1da177e4 LT	85	void via_irq_enable(int irq);
	86	void via_irq_disable(int irq);
	87	void via_irq_clear(int irq);
	88
2850bc27	89	extern irqreturn_t mac_scc_dispatch(int, void *);
1da177e4 LT	90	extern int oss_present;
	91
	92	/*
	93	* Initialize the VIAs
	94	*
	95	* First we figure out where they actually _are_ as well as what type of
	96	* VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
	97	* Then we pretty much clear them out and disable all IRQ sources.
	98	*
	99	* Note: the OSS is actually "detected" here and not in oss_init(). It just
	100	* seems more logical to do it here since via_init() needs to know
	101	* these things anyways.
	102	*/
	103
	104	void __init via_init(void)
	105	{
	106	switch(macintosh_config->via_type) {
	107
	108	/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
	109
	110	case MAC_VIA_IIci:
	111	via1 = (void *) VIA1_BASE;
	112	if (macintosh_config->ident == MAC_MODEL_IIFX) {
	113	via2 = NULL;
	114	rbv_present = 0;
	115	oss_present = 1;
	116	} else {
	117	via2 = (void *) RBV_BASE;
	118	rbv_present = 1;
	119	oss_present = 0;
	120	}
	121	if (macintosh_config->ident == MAC_MODEL_LCIII) {
	122	rbv_clear = 0x00;
	123	} else {
	124	/* on most RBVs (& unlike the VIAs), you */
	125	/* need to set bit 7 when you write to IFR */
	126	/* in order for your clear to occur. */
	127	rbv_clear = 0x80;
	128	}
	129	gIER = rIER;
	130	gIFR = rIFR;
	131	gBufA = rSIFR;
	132	gBufB = rBufB;
	133	break;
	134
	135	/* Quadra and early MacIIs agree on the VIA locations */
	136
	137	case MAC_VIA_QUADRA:
	138	case MAC_VIA_II:
	139	via1 = (void *) VIA1_BASE;
	140	via2 = (void *) VIA2_BASE;
	141	rbv_present = 0;
	142	oss_present = 0;
	143	rbv_clear = 0x00;
	144	gIER = vIER;
	145	gIFR = vIFR;
	146	gBufA = vBufA;
	147	gBufB = vBufB;
	148	break;
	149	default:
	150	panic("UNKNOWN VIA TYPE");
	151	}
	152
	153	printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
154
155	printk(KERN_INFO "VIA2 at %p is ", via2);
156	if (rbv_present) {
67dfb153	157	printk("an RBV\n");
1da177e4	158	} else if (oss_present) {
67dfb153	159	printk("an OSS\n");
1da177e4	160	} else {
67dfb153	161	printk("a 6522 or clone\n");
1da177e4 LT	162	}
	163
	164	#ifdef DEBUG_VIA
	165	via_debug_dump();
	166	#endif
	167
	168	/*
	169	* Shut down all IRQ sources, reset the timers, and
	170	* kill the timer latch on VIA1.
	171	*/
	172
	173	via1[vIER] = 0x7F;
	174	via1[vIFR] = 0x7F;
	175	via1[vT1LL] = 0;
	176	via1[vT1LH] = 0;
	177	via1[vT1CL] = 0;
	178	via1[vT1CH] = 0;
	179	via1[vT2CL] = 0;
	180	via1[vT2CH] = 0;
	181	via1[vACR] &= 0x3F;
67dfb153	182	via1[vACR] &= ~0x03; /* disable port A & B latches */
1da177e4 LT	183
	184	/*
	185	* SE/30: disable video IRQ
	186	* XXX: testing for SE/30 VBL
	187	*/
	188
	189	if (macintosh_config->ident == MAC_MODEL_SE30) {
	190	via1[vDirB] \|= 0x40;
	191	via1[vBufB] \|= 0x40;
	192	}
	193
	194	/*
	195	* Set the RTC bits to a known state: all lines to outputs and
	196	* RTC disabled (yes that's 0 to enable and 1 to disable).
	197	*/
	198
	199	via1[vDirB] \|= (VIA1B_vRTCEnb \| VIA1B_vRTCClk \| VIA1B_vRTCData);
	200	via1[vBufB] \|= (VIA1B_vRTCEnb \| VIA1B_vRTCClk);
	201
	202	/* Everything below this point is VIA2/RBV only... */
	203
	204	if (oss_present) return;
	205
	206	#if 1
	207	/* Some machines support an alternate IRQ mapping that spreads */
	208	/* Ethernet and Sound out to their own autolevel IRQs and moves */
	209	/* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
	210	/* that the IIfx emulates this alternate mapping using the OSS. */
	211
	212	switch(macintosh_config->ident) {
e10e5c43 FT	213	case MAC_MODEL_P475:
	214	case MAC_MODEL_P475F:
	215	case MAC_MODEL_P575:
	216	case MAC_MODEL_Q605:
	217	case MAC_MODEL_Q605_ACC:
1da177e4 LT	218	case MAC_MODEL_C610:
1da177e4 LT	219	case MAC_MODEL_Q610:
e10e5c43	220	case MAC_MODEL_Q630:
1da177e4 LT	221	case MAC_MODEL_C650:
	222	case MAC_MODEL_Q650:
	223	case MAC_MODEL_Q700:
	224	case MAC_MODEL_Q800:
	225	case MAC_MODEL_Q900:
	226	case MAC_MODEL_Q950:
	227	via_alt_mapping = 1;
	228	via1[vDirB] \|= 0x40;
	229	via1[vBufB] &= ~0x40;
	230	break;
	231	default:
	232	via_alt_mapping = 0;
	233	break;
	234	}
	235	#else
1da177e4 LT	236	via_alt_mapping = 0;
	237	#endif
	238
	239	/*
	240	* Now initialize VIA2. For RBV we just kill all interrupts;
	241	* for a regular VIA we also reset the timers and stuff.
	242	*/
	243
	244	via2[gIER] = 0x7F;
	245	via2[gIFR] = 0x7F \| rbv_clear;
	246	if (!rbv_present) {
	247	via2[vT1LL] = 0;
	248	via2[vT1LH] = 0;
	249	via2[vT1CL] = 0;
	250	via2[vT1CH] = 0;
	251	via2[vT2CL] = 0;
	252	via2[vT2CH] = 0;
	253	via2[vACR] &= 0x3F;
67dfb153 FT	254	via2[vACR] &= ~0x03; /* disable port A & B latches */
	255	}
	256
	257	/*
	258	* Set vPCR for SCSI interrupts (but not on RBV)
	259	*/
	260	if (!rbv_present) {
	261	if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
	262	/* CB2 (IRQ) indep. input, positive edge */
	263	/* CA2 (DRQ) indep. input, positive edge */
	264	via2[vPCR] = 0x66;
	265	} else {
	266	/* CB2 (IRQ) indep. input, negative edge */
	267	/* CA2 (DRQ) indep. input, negative edge */
	268	via2[vPCR] = 0x22;
	269	}
1da177e4 LT	270	}
	271	}
	272
	273	/*
	274	* Start the 100 Hz clock
	275	*/
	276
40220c1a	277	void __init via_init_clock(irq_handler_t func)
1da177e4 LT	278	{
	279	via1[vACR] \|= 0x40;
	280	via1[vT1LL] = MAC_CLOCK_LOW;
	281	via1[vT1LH] = MAC_CLOCK_HIGH;
	282	via1[vT1CL] = MAC_CLOCK_LOW;
	283	via1[vT1CH] = MAC_CLOCK_HIGH;
	284
	285	request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
	286	}
	287
	288	/*
	289	* Register the interrupt dispatchers for VIA or RBV machines only.
	290	*/
	291
	292	void __init via_register_interrupts(void)
	293	{
	294	if (via_alt_mapping) {
9c5f4afd	295	request_irq(IRQ_AUTO_1, via1_irq,
1da177e4 LT	296	IRQ_FLG_LOCK\|IRQ_FLG_FAST, "software",
1da177e4 LT	297	(void *) via1);
9c5f4afd	298	request_irq(IRQ_AUTO_6, via1_irq,
1da177e4 LT	299	IRQ_FLG_LOCK\|IRQ_FLG_FAST, "via1",
	300	(void *) via1);
	301	} else {
9c5f4afd	302	request_irq(IRQ_AUTO_1, via1_irq,
1da177e4 LT	303	IRQ_FLG_LOCK\|IRQ_FLG_FAST, "via1",
1da177e4 LT	304	(void *) via1);
1da177e4	305	}
9c5f4afd	306	request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK\|IRQ_FLG_FAST,
1da177e4 LT	307	"via2", (void *) via2);
1da177e4 LT	308	if (!psc_present) {
9c5f4afd	309	request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
1da177e4 LT	310	"scc", mac_scc_dispatch);
	311	}
	312	request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK\|IRQ_FLG_FAST,
	313	"nubus", (void *) via2);
	314	}
	315
	316	/*
	317	* Debugging dump, used in various places to see what's going on.
	318	*/
	319
	320	void via_debug_dump(void)
	321	{
	322	printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
	323	(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
	324	printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
	325	(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
	326	if (oss_present) {
	327	printk(KERN_DEBUG "VIA2: <OSS>\n");
	328	} else if (rbv_present) {
	329	printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
	330	(uint) via2[rIFR], (uint) via2[rIER]);
	331	printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
	332	(uint) via2[rSIFR], (uint) via2[rSIER]);
	333	} else {
	334	printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
	335	(uint) via2[vDirA], (uint) via2[vDirB],
	336	(uint) via2[vACR]);
	337	printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
	338	(uint) via2[vPCR],
	339	(uint) via2[vIFR], (uint) via2[vIER]);
	340	}
	341	}
	342
	343	/*
	344	* This is always executed with interrupts disabled.
	345	*
	346	* TBI: get time offset between scheduling timer ticks
	347	*/
	348
	349	unsigned long mac_gettimeoffset (void)
	350	{
	351	unsigned long ticks, offset = 0;
	352
	353	/* read VIA1 timer 2 current value */
	354	ticks = via1[vT1CL] \| (via1[vT1CH] << 8);
	355	/* The probability of underflow is less than 2% */
	356	if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
	357	/* Check for pending timer interrupt in VIA1 IFR */
	358	if (via1[vIFR] & 0x40) offset = TICK_SIZE;
	359
	360	ticks = MAC_CLOCK_TICK - ticks;
	361	ticks = ticks * 10000L / MAC_CLOCK_TICK;
	362
	363	return ticks + offset;
	364	}
	365
	366	/*
	367	* Flush the L2 cache on Macs that have it by flipping
	368	* the system into 24-bit mode for an instant.
	369	*/
	370
	371	void via_flush_cache(void)
	372	{
	373	via2[gBufB] &= ~VIA2B_vMode32;
374	via2[gBufB] \|= VIA2B_vMode32;
375	}
376
377	/*
378	* Return the status of the L2 cache on a IIci
379	*/
380
381	int via_get_cache_disable(void)
382	{
383	/* Safeguard against being called accidentally */
384	if (!via2) {
385	printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
386	return 1;
387	}
388
389	return (int) via2[gBufB] & VIA2B_vCDis;
390	}
391
392	/*
393	* Initialize VIA2 for Nubus access
394	*/
395
396	void __init via_nubus_init(void)
397	{
1da177e4 LT	398	/* unlock nubus transactions */
1da177e4 LT	399
67dfb153 FT	400	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
67dfb153 FT	401	(macintosh_config->adb_type != MAC_ADB_PB2)) {
1da177e4	402	/* set the line to be an output on non-RBV machines */
67dfb153	403	if (!rbv_present)
1da177e4	404	via2[vDirB] \|= 0x02;
1da177e4	405
67dfb153 FT	406	/* this seems to be an ADB bit on PMU machines */
67dfb153 FT	407	/* according to MkLinux. -- jmt */
1da177e4 LT	408	via2[gBufB] \|= 0x02;
	409	}
	410
cd713ddc FT	411	/* Disable all the slot interrupts (where possible). */
	412
	413	switch (macintosh_config->via_type) {
	414	case MAC_VIA_II:
	415	/* Just make the port A lines inputs. */
	416	switch(macintosh_config->ident) {
	417	case MAC_MODEL_II:
	418	case MAC_MODEL_IIX:
	419	case MAC_MODEL_IICX:
	420	case MAC_MODEL_SE30:
	421	/* The top two bits are RAM size outputs. */
	422	via2[vDirA] &= 0xC0;
	423	break;
	424	default:
	425	via2[vDirA] &= 0x80;
	426	}
	427	break;
	428	case MAC_VIA_IIci:
	429	/* RBV. Disable all the slot interrupts. SIER works like IER. */
1da177e4	430	via2[rSIER] = 0x7F;
cd713ddc FT	431	break;
	432	case MAC_VIA_QUADRA:
	433	/* Disable the inactive slot interrupts by making those lines outputs. */
1da177e4	434	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
cd713ddc FT	435	(macintosh_config->adb_type != MAC_ADB_PB2)) {
	436	via2[vBufA] \|= 0x7F;
	437	via2[vDirA] \|= 0x7F;
1da177e4	438	}
cd713ddc	439	break;
1da177e4 LT	440	}
	441	}
	442
	443	/*
	444	* The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
	445	* via6522.c :-), disable/pending masks added.
1da177e4 LT	446	*/
1da177e4 LT	447
2850bc27	448	irqreturn_t via1_irq(int irq, void *dev_id)
1da177e4	449	{
67dfb153 FT	450	int irq_num;
67dfb153 FT	451	unsigned char irq_bit, events;
1da177e4	452
67dfb153 FT	453	events = via1[vIFR] & via1[vIER] & 0x7F;
67dfb153 FT	454	if (!events)
1da177e4 LT	455	return IRQ_NONE;
1da177e4 LT	456
67dfb153 FT	457	irq_num = VIA1_SOURCE_BASE;
	458	irq_bit = 1;
	459	do {
1da177e4	460	if (events & irq_bit) {
1da177e4	461	via1[vIFR] = irq_bit;
67dfb153	462	m68k_handle_int(irq_num);
1da177e4	463	}
67dfb153 FT	464	++irq_num;
	465	irq_bit <<= 1;
	466	} while (events >= irq_bit);
1da177e4 LT	467
	468	#if 0 /* freakin' pmu is doing weird stuff */
	469	if (!oss_present) {
	470	/* This (still) seems to be necessary to get IDE
	471	working. However, if you enable VBL interrupts,
	472	you're screwed... */
	473	/* FIXME: should we check the SLOTIRQ bit before
	474	pulling this stunt? */
	475	/* No, it won't be set. that's why we're doing this. */
	476	via_irq_disable(IRQ_MAC_NUBUS);
	477	via_irq_clear(IRQ_MAC_NUBUS);
2850bc27	478	m68k_handle_int(IRQ_MAC_NUBUS);
1da177e4 LT	479	via_irq_enable(IRQ_MAC_NUBUS);
	480	}
	481	#endif
	482	return IRQ_HANDLED;
	483	}
	484
2850bc27	485	irqreturn_t via2_irq(int irq, void *dev_id)
1da177e4	486	{
67dfb153 FT	487	int irq_num;
67dfb153 FT	488	unsigned char irq_bit, events;
1da177e4	489
67dfb153 FT	490	events = via2[gIFR] & via2[gIER] & 0x7F;
67dfb153 FT	491	if (!events)
1da177e4 LT	492	return IRQ_NONE;
1da177e4 LT	493
67dfb153 FT	494	irq_num = VIA2_SOURCE_BASE;
	495	irq_bit = 1;
	496	do {
1da177e4	497	if (events & irq_bit) {
1da177e4	498	via2[gIFR] = irq_bit \| rbv_clear;
67dfb153	499	m68k_handle_int(irq_num);
1da177e4	500	}
67dfb153 FT	501	++irq_num;
	502	irq_bit <<= 1;
	503	} while (events >= irq_bit);
1da177e4 LT	504	return IRQ_HANDLED;
	505	}
	506
	507	/*
	508	* Dispatch Nubus interrupts. We are called as a secondary dispatch by the
	509	* VIA2 dispatcher as a fast interrupt handler.
	510	*/
	511
2850bc27	512	irqreturn_t via_nubus_irq(int irq, void *dev_id)
1da177e4	513	{
67dfb153 FT	514	int slot_irq;
	515	unsigned char slot_bit, events;
	516
	517	events = ~via2[gBufA] & 0x7F;
	518	if (rbv_present)
	519	events &= via2[rSIER];
	520	else
cd713ddc	521	events &= ~via2[vDirA];
67dfb153	522	if (!events)
1da177e4 LT	523	return IRQ_NONE;
1da177e4 LT	524
67dfb153 FT	525	do {
	526	slot_irq = IRQ_NUBUS_F;
	527	slot_bit = 0x40;
	528	do {
	529	if (events & slot_bit) {
	530	events &= ~slot_bit;
	531	m68k_handle_int(slot_irq);
	532	}
	533	--slot_irq;
	534	slot_bit >>= 1;
	535	} while (events);
	536
	537	/* clear the CA1 interrupt and make certain there's no more. */
	538	via2[gIFR] = 0x02 \| rbv_clear;
	539	events = ~via2[gBufA] & 0x7F;
	540	if (rbv_present)
	541	events &= via2[rSIER];
	542	else
cd713ddc	543	events &= ~via2[vDirA];
67dfb153	544	} while (events);
1da177e4 LT	545	return IRQ_HANDLED;
	546	}
	547
	548	void via_irq_enable(int irq) {
	549	int irq_src = IRQ_SRC(irq);
	550	int irq_idx = IRQ_IDX(irq);
1da177e4 LT	551
	552	#ifdef DEBUG_IRQUSE
	553	printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
	554	#endif
	555
	556	if (irq_src == 1) {
cd713ddc	557	via1[vIER] = IER_SET_BIT(irq_idx);
1da177e4	558	} else if (irq_src == 2) {
cd713ddc FT	559	if (irq != IRQ_MAC_NUBUS \|\| nubus_disabled == 0)
cd713ddc FT	560	via2[gIER] = IER_SET_BIT(irq_idx);
1da177e4	561	} else if (irq_src == 7) {
cd713ddc FT	562	switch (macintosh_config->via_type) {
	563	case MAC_VIA_II:
	564	nubus_disabled &= ~(1 << irq_idx);
	565	/* Enable the CA1 interrupt when no slot is disabled. */
	566	if (!nubus_disabled)
	567	via2[gIER] = IER_SET_BIT(1);
	568	break;
	569	case MAC_VIA_IIci:
	570	/* On RBV, enable the slot interrupt.
	571	* SIER works like IER.
	572	*/
1da177e4	573	via2[rSIER] = IER_SET_BIT(irq_idx);
cd713ddc FT	574	break;
	575	case MAC_VIA_QUADRA:
	576	/* Make the port A line an input to enable the slot irq.
	577	* But not on PowerBooks, that's ADB.
	578	*/
1da177e4	579	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
cd713ddc FT	580	(macintosh_config->adb_type != MAC_ADB_PB2))
	581	via2[vDirA] &= ~(1 << irq_idx);
	582	break;
1da177e4	583	}
1da177e4 LT	584	}
	585	}
	586
	587	void via_irq_disable(int irq) {
	588	int irq_src = IRQ_SRC(irq);
	589	int irq_idx = IRQ_IDX(irq);
1da177e4 LT	590
	591	#ifdef DEBUG_IRQUSE
	592	printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
	593	#endif
	594
	595	if (irq_src == 1) {
cd713ddc	596	via1[vIER] = IER_CLR_BIT(irq_idx);
1da177e4	597	} else if (irq_src == 2) {
cd713ddc	598	via2[gIER] = IER_CLR_BIT(irq_idx);
1da177e4	599	} else if (irq_src == 7) {
cd713ddc FT	600	switch (macintosh_config->via_type) {
	601	case MAC_VIA_II:
	602	nubus_disabled \|= 1 << irq_idx;
	603	if (nubus_disabled)
	604	via2[gIER] = IER_CLR_BIT(1);
	605	break;
	606	case MAC_VIA_IIci:
1da177e4	607	via2[rSIER] = IER_CLR_BIT(irq_idx);
cd713ddc FT	608	break;
cd713ddc FT	609	case MAC_VIA_QUADRA:
1da177e4	610	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
cd713ddc FT	611	(macintosh_config->adb_type != MAC_ADB_PB2))
	612	via2[vDirA] \|= 1 << irq_idx;
	613	break;
1da177e4	614	}
1da177e4 LT	615	}
	616	}
	617
	618	void via_irq_clear(int irq) {
	619	int irq_src = IRQ_SRC(irq);
	620	int irq_idx = IRQ_IDX(irq);
	621	int irq_bit = 1 << irq_idx;
	622
	623	if (irq_src == 1) {
	624	via1[vIFR] = irq_bit;
	625	} else if (irq_src == 2) {
	626	via2[gIFR] = irq_bit \| rbv_clear;
	627	} else if (irq_src == 7) {
67dfb153 FT	628	/* FIXME: There is no way to clear an individual nubus slot
	629	* IRQ flag, other than getting the device to do it.
	630	*/
1da177e4 LT	631	}
	632	}
	633
	634	/*
	635	* Returns nonzero if an interrupt is pending on the given
	636	* VIA/IRQ combination.
	637	*/
	638
	639	int via_irq_pending(int irq)
	640	{
	641	int irq_src = IRQ_SRC(irq);
	642	int irq_idx = IRQ_IDX(irq);
	643	int irq_bit = 1 << irq_idx;
	644
	645	if (irq_src == 1) {
	646	return via1[vIFR] & irq_bit;
	647	} else if (irq_src == 2) {
	648	return via2[gIFR] & irq_bit;
	649	} else if (irq_src == 7) {
cd713ddc	650	/* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
1da177e4 LT	651	return ~via2[gBufA] & irq_bit;
	652	}
	653	return 0;
	654	}