[mirror_ubuntu-artful-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/module.h>
#ifdef CONFIG_GENERIC_HARDIRQS
#include <linux/irq.h>
#endif

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

volatile __u8 *via1, *via2;
int rbv_present;
int via_alt_mapping;
EXPORT_SYMBOL(via_alt_mapping);
static __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 that slot IRQ line an output 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);

/*
 * 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] &= ~0xC0; /* setup T1 timer with no PB7 output */
	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;

	/* 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. */

	via_alt_mapping = 0;
	if (macintosh_config->via_type == MAC_VIA_QUADRA)
		switch (macintosh_config->ident) {
		case MAC_MODEL_C660:
		case MAC_MODEL_Q840:
			/* not applicable */
			break;
		case MAC_MODEL_P588:
		case MAC_MODEL_TV:
		case MAC_MODEL_PB140:
		case MAC_MODEL_PB145:
		case MAC_MODEL_PB160:
		case MAC_MODEL_PB165:
		case MAC_MODEL_PB165C:
		case MAC_MODEL_PB170:
		case MAC_MODEL_PB180:
		case MAC_MODEL_PB180C:
		case MAC_MODEL_PB190:
		case MAC_MODEL_PB520:
			/* not yet tested */
			break;
		default:
			via_alt_mapping = 1;
			via1[vDirB] |= 0x40;
			via1[vBufB] &= ~0x40;
			break;
		}

	/*
	 * 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] &= ~0xC0; /* setup T1 timer with no PB7 output */
		via2[vACR] &= ~0x03; /* disable port A & B latches */
	}

	/*
	 * Set vPCR for control line interrupts (but not on RBV)
	 */
	if (!rbv_present) {
		/* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
		 * are made negative edge triggered here.
		 */
		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;

	if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func))
		pr_err("Couldn't register %s interrupt\n", "timer");
}

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

void __init via_register_interrupts(void)
{
	if (via_alt_mapping) {
		if (request_irq(IRQ_AUTO_1, via1_irq, 0, "software",
				(void *)via1))
			pr_err("Couldn't register %s interrupt\n", "software");
		if (request_irq(IRQ_AUTO_6, via1_irq, 0, "via1", (void *)via1))
			pr_err("Couldn't register %s interrupt\n", "via1");
	} else {
		if (request_irq(IRQ_AUTO_1, via1_irq, 0, "via1", (void *)via1))
			pr_err("Couldn't register %s interrupt\n", "via1");
	}
	if (request_irq(IRQ_AUTO_2, via2_irq, 0, "via2", (void *)via2))
		pr_err("Couldn't register %s interrupt\n", "via2");
	if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq, 0, "nubus",
			(void *)via2))
		pr_err("Couldn't register %s interrupt\n", "nubus");
}

/*
 * 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;
			generic_handle_irq(irq_num);
		}
		++irq_num;
		irq_bit <<= 1;
	} while (events >= irq_bit);
	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;
			generic_handle_irq(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;
				generic_handle_irq(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;
}

void via1_set_head(int head)
{
	if (head == 0)
		via1[vBufA] &= ~VIA1A_vHeadSel;
	else
		via1[vBufA] |= VIA1A_vHeadSel;
}
EXPORT_SYMBOL(via1_set_head);
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>
deea7775	30	#include <linux/module.h>
ddc7fd25 GU	31	#ifdef CONFIG_GENERIC_HARDIRQS
	32	#include <linux/irq.h>
	33	#endif
1da177e4	34
1da177e4 LT	35	#include <asm/bootinfo.h>
	36	#include <asm/macintosh.h>
	37	#include <asm/macints.h>
1da177e4 LT	38	#include <asm/mac_via.h>
1da177e4 LT	39	#include <asm/mac_psc.h>
c85627fb	40	#include <asm/mac_oss.h>
1da177e4 LT	41
1da177e4 LT	42	volatile __u8 via1, via2;
deea7775 AB	43	int rbv_present;
	44	int via_alt_mapping;
	45	EXPORT_SYMBOL(via_alt_mapping);
8dfbdf4a	46	static __u8 rbv_clear;
1da177e4 LT	47
	48	/*
	49	* Globals for accessing the VIA chip registers without having to
	50	* check if we're hitting a real VIA or an RBV. Normally you could
	51	* just hit the combined register (ie, vIER\|rIER) but that seems to
	52	* break on AV Macs...probably because they actually decode more than
	53	* eight address bits. Why can't Apple engineers at least be
	54	* _consistently_ lazy? - 1999-05-21 (jmt)
	55	*/
	56
	57	static int gIER,gIFR,gBufA,gBufB;
	58
	59	/*
	60	* Timer defs.
	61	*/
	62
	63	#define TICK_SIZE 10000
	64	#define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
	65	#define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
	66	#define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
	67
4a973592	68	/* To disable a NuBus slot on Quadras we make that slot IRQ line an output set
cd713ddc FT	69	* high. On RBV we just use the slot interrupt enable register. On Macs with
	70	* genuine VIA chips we must use nubus_disabled to keep track of disabled slot
	71	* interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
	72	* or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
	73	* So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
	74	* because closing one of those drivers can mask all of the NuBus interrupts.
	75	* Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
	76	* possible to get interrupts from cards that MacOS or the ROM has configured
	77	* but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
	78	* Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
	79	*/
	80	static u8 nubus_disabled;
1da177e4 LT	81
1da177e4 LT	82	void via_debug_dump(void);
2850bc27 AV	83	irqreturn_t via1_irq(int, void *);
	84	irqreturn_t via2_irq(int, void *);
	85	irqreturn_t via_nubus_irq(int, void *);
1da177e4 LT	86	void via_irq_enable(int irq);
	87	void via_irq_disable(int irq);
	88	void via_irq_clear(int irq);
	89
1da177e4 LT	90	/*
	91	* Initialize the VIAs
	92	*
	93	* First we figure out where they actually _are_ as well as what type of
	94	* VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
	95	* Then we pretty much clear them out and disable all IRQ sources.
	96	*
	97	* Note: the OSS is actually "detected" here and not in oss_init(). It just
	98	* seems more logical to do it here since via_init() needs to know
	99	* these things anyways.
	100	*/
	101
	102	void __init via_init(void)
	103	{
	104	switch(macintosh_config->via_type) {
	105
	106	/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
	107
	108	case MAC_VIA_IIci:
	109	via1 = (void *) VIA1_BASE;
	110	if (macintosh_config->ident == MAC_MODEL_IIFX) {
	111	via2 = NULL;
	112	rbv_present = 0;
	113	oss_present = 1;
	114	} else {
	115	via2 = (void *) RBV_BASE;
	116	rbv_present = 1;
	117	oss_present = 0;
	118	}
	119	if (macintosh_config->ident == MAC_MODEL_LCIII) {
	120	rbv_clear = 0x00;
	121	} else {
	122	/* on most RBVs (& unlike the VIAs), you */
	123	/* need to set bit 7 when you write to IFR */
	124	/* in order for your clear to occur. */
	125	rbv_clear = 0x80;
	126	}
	127	gIER = rIER;
	128	gIFR = rIFR;
	129	gBufA = rSIFR;
	130	gBufB = rBufB;
	131	break;
	132
	133	/* Quadra and early MacIIs agree on the VIA locations */
	134
	135	case MAC_VIA_QUADRA:
	136	case MAC_VIA_II:
	137	via1 = (void *) VIA1_BASE;
	138	via2 = (void *) VIA2_BASE;
	139	rbv_present = 0;
	140	oss_present = 0;
	141	rbv_clear = 0x00;
	142	gIER = vIER;
	143	gIFR = vIFR;
	144	gBufA = vBufA;
	145	gBufB = vBufB;
	146	break;
	147	default:
	148	panic("UNKNOWN VIA TYPE");
	149	}
	150
	151	printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
	152
	153	printk(KERN_INFO "VIA2 at %p is ", via2);
154	if (rbv_present) {
67dfb153	155	printk("an RBV\n");
1da177e4	156	} else if (oss_present) {
67dfb153	157	printk("an OSS\n");
1da177e4	158	} else {
67dfb153	159	printk("a 6522 or clone\n");
1da177e4 LT	160	}
	161
	162	#ifdef DEBUG_VIA
	163	via_debug_dump();
	164	#endif
	165
	166	/*
	167	* Shut down all IRQ sources, reset the timers, and
	168	* kill the timer latch on VIA1.
	169	*/
	170
	171	via1[vIER] = 0x7F;
	172	via1[vIFR] = 0x7F;
	173	via1[vT1LL] = 0;
	174	via1[vT1LH] = 0;
	175	via1[vT1CL] = 0;
	176	via1[vT1CH] = 0;
	177	via1[vT2CL] = 0;
	178	via1[vT2CH] = 0;
4a973592	179	via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
67dfb153	180	via1[vACR] &= ~0x03; /* disable port A & B latches */
1da177e4 LT	181
	182	/*
	183	* SE/30: disable video IRQ
	184	* XXX: testing for SE/30 VBL
	185	*/
	186
	187	if (macintosh_config->ident == MAC_MODEL_SE30) {
	188	via1[vDirB] \|= 0x40;
	189	via1[vBufB] \|= 0x40;
	190	}
	191
	192	/*
	193	* Set the RTC bits to a known state: all lines to outputs and
	194	* RTC disabled (yes that's 0 to enable and 1 to disable).
	195	*/
	196
	197	via1[vDirB] \|= (VIA1B_vRTCEnb \| VIA1B_vRTCClk \| VIA1B_vRTCData);
	198	via1[vBufB] \|= (VIA1B_vRTCEnb \| VIA1B_vRTCClk);
	199
	200	/* Everything below this point is VIA2/RBV only... */
	201
4a973592 FT	202	if (oss_present)
4a973592 FT	203	return;
1da177e4	204
1da177e4 LT	205	/* Some machines support an alternate IRQ mapping that spreads */
	206	/* Ethernet and Sound out to their own autolevel IRQs and moves */
	207	/* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
	208	/* that the IIfx emulates this alternate mapping using the OSS. */
	209
4a973592 FT	210	via_alt_mapping = 0;
	211	if (macintosh_config->via_type == MAC_VIA_QUADRA)
	212	switch (macintosh_config->ident) {
	213	case MAC_MODEL_C660:
	214	case MAC_MODEL_Q840:
	215	/* not applicable */
	216	break;
	217	case MAC_MODEL_P588:
	218	case MAC_MODEL_TV:
	219	case MAC_MODEL_PB140:
	220	case MAC_MODEL_PB145:
	221	case MAC_MODEL_PB160:
	222	case MAC_MODEL_PB165:
	223	case MAC_MODEL_PB165C:
	224	case MAC_MODEL_PB170:
	225	case MAC_MODEL_PB180:
	226	case MAC_MODEL_PB180C:
	227	case MAC_MODEL_PB190:
	228	case MAC_MODEL_PB520:
	229	/* not yet tested */
	230	break;
	231	default:
1da177e4 LT	232	via_alt_mapping = 1;
	233	via1[vDirB] \|= 0x40;
	234	via1[vBufB] &= ~0x40;
	235	break;
4a973592	236	}
1da177e4 LT	237
	238	/*
	239	* Now initialize VIA2. For RBV we just kill all interrupts;
	240	* for a regular VIA we also reset the timers and stuff.
	241	*/
	242
	243	via2[gIER] = 0x7F;
	244	via2[gIFR] = 0x7F \| rbv_clear;
	245	if (!rbv_present) {
	246	via2[vT1LL] = 0;
	247	via2[vT1LH] = 0;
	248	via2[vT1CL] = 0;
	249	via2[vT1CH] = 0;
	250	via2[vT2CL] = 0;
	251	via2[vT2CH] = 0;
4a973592	252	via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
67dfb153 FT	253	via2[vACR] &= ~0x03; /* disable port A & B latches */
	254	}
	255
	256	/*
4a973592	257	* Set vPCR for control line interrupts (but not on RBV)
67dfb153 FT	258	*/
67dfb153 FT	259	if (!rbv_present) {
4a973592 FT	260	/* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
	261	* are made negative edge triggered here.
	262	*/
67dfb153 FT	263	if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
	264	/* CB2 (IRQ) indep. input, positive edge */
	265	/* CA2 (DRQ) indep. input, positive edge */
	266	via2[vPCR] = 0x66;
	267	} else {
	268	/* CB2 (IRQ) indep. input, negative edge */
	269	/* CA2 (DRQ) indep. input, negative edge */
	270	via2[vPCR] = 0x22;
	271	}
1da177e4 LT	272	}
	273	}
	274
	275	/*
	276	* Start the 100 Hz clock
	277	*/
	278
40220c1a	279	void __init via_init_clock(irq_handler_t func)
1da177e4 LT	280	{
	281	via1[vACR] \|= 0x40;
	282	via1[vT1LL] = MAC_CLOCK_LOW;
	283	via1[vT1LH] = MAC_CLOCK_HIGH;
	284	via1[vT1CL] = MAC_CLOCK_LOW;
	285	via1[vT1CH] = MAC_CLOCK_HIGH;
	286
5a239453	287	if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func))
92c3dd15	288	pr_err("Couldn't register %s interrupt\n", "timer");
1da177e4 LT	289	}
	290
	291	/*
	292	* Register the interrupt dispatchers for VIA or RBV machines only.
	293	*/
	294
	295	void __init via_register_interrupts(void)
	296	{
	297	if (via_alt_mapping) {
5a239453 GU	298	if (request_irq(IRQ_AUTO_1, via1_irq, 0, "software",
5a239453 GU	299	(void *)via1))
92c3dd15	300	pr_err("Couldn't register %s interrupt\n", "software");
5a239453	301	if (request_irq(IRQ_AUTO_6, via1_irq, 0, "via1", (void *)via1))
92c3dd15	302	pr_err("Couldn't register %s interrupt\n", "via1");
1da177e4	303	} else {
5a239453	304	if (request_irq(IRQ_AUTO_1, via1_irq, 0, "via1", (void *)via1))
92c3dd15	305	pr_err("Couldn't register %s interrupt\n", "via1");
1da177e4	306	}
5a239453	307	if (request_irq(IRQ_AUTO_2, via2_irq, 0, "via2", (void *)via2))
92c3dd15	308	pr_err("Couldn't register %s interrupt\n", "via2");
5a239453 GU	309	if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq, 0, "nubus",
5a239453 GU	310	(void *)via2))
92c3dd15	311	pr_err("Couldn't register %s interrupt\n", "nubus");
1da177e4 LT	312	}
	313
	314	/*
	315	* Debugging dump, used in various places to see what's going on.
	316	*/
	317
	318	void via_debug_dump(void)
	319	{
	320	printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
	321	(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
	322	printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
	323	(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
	324	if (oss_present) {
	325	printk(KERN_DEBUG "VIA2: <OSS>\n");
	326	} else if (rbv_present) {
	327	printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
	328	(uint) via2[rIFR], (uint) via2[rIER]);
	329	printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
	330	(uint) via2[rSIFR], (uint) via2[rSIER]);
	331	} else {
	332	printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
	333	(uint) via2[vDirA], (uint) via2[vDirB],
	334	(uint) via2[vACR]);
	335	printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
	336	(uint) via2[vPCR],
	337	(uint) via2[vIFR], (uint) via2[vIER]);
	338	}
	339	}
	340
	341	/*
	342	* This is always executed with interrupts disabled.
	343	*
	344	* TBI: get time offset between scheduling timer ticks
	345	*/
	346
	347	unsigned long mac_gettimeoffset (void)
	348	{
	349	unsigned long ticks, offset = 0;
	350
	351	/* read VIA1 timer 2 current value */
	352	ticks = via1[vT1CL] \| (via1[vT1CH] << 8);
	353	/* The probability of underflow is less than 2% */
	354	if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
	355	/* Check for pending timer interrupt in VIA1 IFR */
	356	if (via1[vIFR] & 0x40) offset = TICK_SIZE;
	357
	358	ticks = MAC_CLOCK_TICK - ticks;
	359	ticks = ticks * 10000L / MAC_CLOCK_TICK;
	360
	361	return ticks + offset;
	362	}
	363
	364	/*
	365	* Flush the L2 cache on Macs that have it by flipping
	366	* the system into 24-bit mode for an instant.
	367	*/
	368
	369	void via_flush_cache(void)
	370	{
	371	via2[gBufB] &= ~VIA2B_vMode32;
	372	via2[gBufB] \|= VIA2B_vMode32;
	373	}
	374
	375	/*
376	* Return the status of the L2 cache on a IIci
377	*/
378
379	int via_get_cache_disable(void)
380	{
381	/* Safeguard against being called accidentally */
382	if (!via2) {
383	printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
384	return 1;
385	}
386
387	return (int) via2[gBufB] & VIA2B_vCDis;
388	}
389
390	/*
391	* Initialize VIA2 for Nubus access
392	*/
393
394	void __init via_nubus_init(void)
395	{
1da177e4 LT	396	/* unlock nubus transactions */
1da177e4 LT	397
67dfb153 FT	398	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
67dfb153 FT	399	(macintosh_config->adb_type != MAC_ADB_PB2)) {
1da177e4	400	/* set the line to be an output on non-RBV machines */
67dfb153	401	if (!rbv_present)
1da177e4	402	via2[vDirB] \|= 0x02;
1da177e4	403
67dfb153 FT	404	/* this seems to be an ADB bit on PMU machines */
67dfb153 FT	405	/* according to MkLinux. -- jmt */
1da177e4 LT	406	via2[gBufB] \|= 0x02;
	407	}
	408
cd713ddc FT	409	/* Disable all the slot interrupts (where possible). */
	410
	411	switch (macintosh_config->via_type) {
	412	case MAC_VIA_II:
	413	/* Just make the port A lines inputs. */
	414	switch(macintosh_config->ident) {
	415	case MAC_MODEL_II:
	416	case MAC_MODEL_IIX:
	417	case MAC_MODEL_IICX:
	418	case MAC_MODEL_SE30:
	419	/* The top two bits are RAM size outputs. */
	420	via2[vDirA] &= 0xC0;
	421	break;
	422	default:
	423	via2[vDirA] &= 0x80;
	424	}
	425	break;
	426	case MAC_VIA_IIci:
	427	/* RBV. Disable all the slot interrupts. SIER works like IER. */
1da177e4	428	via2[rSIER] = 0x7F;
cd713ddc FT	429	break;
	430	case MAC_VIA_QUADRA:
	431	/* Disable the inactive slot interrupts by making those lines outputs. */
1da177e4	432	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
cd713ddc FT	433	(macintosh_config->adb_type != MAC_ADB_PB2)) {
	434	via2[vBufA] \|= 0x7F;
	435	via2[vDirA] \|= 0x7F;
1da177e4	436	}
cd713ddc	437	break;
1da177e4 LT	438	}
	439	}
	440
	441	/*
	442	* The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
	443	* via6522.c :-), disable/pending masks added.
1da177e4 LT	444	*/
1da177e4 LT	445
2850bc27	446	irqreturn_t via1_irq(int irq, void *dev_id)
1da177e4	447	{
67dfb153 FT	448	int irq_num;
67dfb153 FT	449	unsigned char irq_bit, events;
1da177e4	450
67dfb153 FT	451	events = via1[vIFR] & via1[vIER] & 0x7F;
67dfb153 FT	452	if (!events)
1da177e4 LT	453	return IRQ_NONE;
1da177e4 LT	454
67dfb153 FT	455	irq_num = VIA1_SOURCE_BASE;
	456	irq_bit = 1;
	457	do {
1da177e4	458	if (events & irq_bit) {
1da177e4	459	via1[vIFR] = irq_bit;
1425df87	460	generic_handle_irq(irq_num);
1da177e4	461	}
67dfb153 FT	462	++irq_num;
	463	irq_bit <<= 1;
	464	} while (events >= irq_bit);
1da177e4 LT	465	return IRQ_HANDLED;
	466	}
	467
2850bc27	468	irqreturn_t via2_irq(int irq, void *dev_id)
1da177e4	469	{
67dfb153 FT	470	int irq_num;
67dfb153 FT	471	unsigned char irq_bit, events;
1da177e4	472
67dfb153 FT	473	events = via2[gIFR] & via2[gIER] & 0x7F;
67dfb153 FT	474	if (!events)
1da177e4 LT	475	return IRQ_NONE;
1da177e4 LT	476
67dfb153 FT	477	irq_num = VIA2_SOURCE_BASE;
	478	irq_bit = 1;
	479	do {
1da177e4	480	if (events & irq_bit) {
1da177e4	481	via2[gIFR] = irq_bit \| rbv_clear;
1425df87	482	generic_handle_irq(irq_num);
1da177e4	483	}
67dfb153 FT	484	++irq_num;
	485	irq_bit <<= 1;
	486	} while (events >= irq_bit);
1da177e4 LT	487	return IRQ_HANDLED;
	488	}
	489
	490	/*
	491	* Dispatch Nubus interrupts. We are called as a secondary dispatch by the
	492	* VIA2 dispatcher as a fast interrupt handler.
	493	*/
	494
2850bc27	495	irqreturn_t via_nubus_irq(int irq, void *dev_id)
1da177e4	496	{
67dfb153 FT	497	int slot_irq;
	498	unsigned char slot_bit, events;
	499
	500	events = ~via2[gBufA] & 0x7F;
	501	if (rbv_present)
	502	events &= via2[rSIER];
	503	else
cd713ddc	504	events &= ~via2[vDirA];
67dfb153	505	if (!events)
1da177e4 LT	506	return IRQ_NONE;
1da177e4 LT	507
67dfb153 FT	508	do {
	509	slot_irq = IRQ_NUBUS_F;
	510	slot_bit = 0x40;
	511	do {
	512	if (events & slot_bit) {
	513	events &= ~slot_bit;
1425df87	514	generic_handle_irq(slot_irq);
67dfb153 FT	515	}
	516	--slot_irq;
	517	slot_bit >>= 1;
	518	} while (events);
	519
	520	/* clear the CA1 interrupt and make certain there's no more. */
	521	via2[gIFR] = 0x02 \| rbv_clear;
	522	events = ~via2[gBufA] & 0x7F;
	523	if (rbv_present)
	524	events &= via2[rSIER];
	525	else
cd713ddc	526	events &= ~via2[vDirA];
67dfb153	527	} while (events);
1da177e4 LT	528	return IRQ_HANDLED;
	529	}
	530
	531	void via_irq_enable(int irq) {
	532	int irq_src = IRQ_SRC(irq);
	533	int irq_idx = IRQ_IDX(irq);
1da177e4 LT	534
	535	#ifdef DEBUG_IRQUSE
	536	printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
	537	#endif
	538
	539	if (irq_src == 1) {
cd713ddc	540	via1[vIER] = IER_SET_BIT(irq_idx);
1da177e4	541	} else if (irq_src == 2) {
cd713ddc FT	542	if (irq != IRQ_MAC_NUBUS \|\| nubus_disabled == 0)
cd713ddc FT	543	via2[gIER] = IER_SET_BIT(irq_idx);
1da177e4	544	} else if (irq_src == 7) {
cd713ddc FT	545	switch (macintosh_config->via_type) {
	546	case MAC_VIA_II:
	547	nubus_disabled &= ~(1 << irq_idx);
	548	/* Enable the CA1 interrupt when no slot is disabled. */
	549	if (!nubus_disabled)
	550	via2[gIER] = IER_SET_BIT(1);
	551	break;
	552	case MAC_VIA_IIci:
	553	/* On RBV, enable the slot interrupt.
	554	* SIER works like IER.
	555	*/
1da177e4	556	via2[rSIER] = IER_SET_BIT(irq_idx);
cd713ddc FT	557	break;
	558	case MAC_VIA_QUADRA:
	559	/* Make the port A line an input to enable the slot irq.
	560	* But not on PowerBooks, that's ADB.
	561	*/
1da177e4	562	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
cd713ddc FT	563	(macintosh_config->adb_type != MAC_ADB_PB2))
	564	via2[vDirA] &= ~(1 << irq_idx);
	565	break;
1da177e4	566	}
1da177e4 LT	567	}
	568	}
	569
	570	void via_irq_disable(int irq) {
	571	int irq_src = IRQ_SRC(irq);
	572	int irq_idx = IRQ_IDX(irq);
1da177e4 LT	573
	574	#ifdef DEBUG_IRQUSE
	575	printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
	576	#endif
	577
	578	if (irq_src == 1) {
cd713ddc	579	via1[vIER] = IER_CLR_BIT(irq_idx);
1da177e4	580	} else if (irq_src == 2) {
cd713ddc	581	via2[gIER] = IER_CLR_BIT(irq_idx);
1da177e4	582	} else if (irq_src == 7) {
cd713ddc FT	583	switch (macintosh_config->via_type) {
	584	case MAC_VIA_II:
	585	nubus_disabled \|= 1 << irq_idx;
	586	if (nubus_disabled)
	587	via2[gIER] = IER_CLR_BIT(1);
	588	break;
	589	case MAC_VIA_IIci:
1da177e4	590	via2[rSIER] = IER_CLR_BIT(irq_idx);
cd713ddc FT	591	break;
cd713ddc FT	592	case MAC_VIA_QUADRA:
1da177e4	593	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
cd713ddc FT	594	(macintosh_config->adb_type != MAC_ADB_PB2))
	595	via2[vDirA] \|= 1 << irq_idx;
	596	break;
1da177e4	597	}
1da177e4 LT	598	}
	599	}
	600
	601	void via_irq_clear(int irq) {
	602	int irq_src = IRQ_SRC(irq);
	603	int irq_idx = IRQ_IDX(irq);
	604	int irq_bit = 1 << irq_idx;
	605
	606	if (irq_src == 1) {
	607	via1[vIFR] = irq_bit;
	608	} else if (irq_src == 2) {
	609	via2[gIFR] = irq_bit \| rbv_clear;
	610	} else if (irq_src == 7) {
67dfb153 FT	611	/* FIXME: There is no way to clear an individual nubus slot
	612	* IRQ flag, other than getting the device to do it.
	613	*/
1da177e4 LT	614	}
	615	}
	616
	617	/*
	618	* Returns nonzero if an interrupt is pending on the given
	619	* VIA/IRQ combination.
	620	*/
	621
	622	int via_irq_pending(int irq)
	623	{
	624	int irq_src = IRQ_SRC(irq);
	625	int irq_idx = IRQ_IDX(irq);
	626	int irq_bit = 1 << irq_idx;
	627
	628	if (irq_src == 1) {
	629	return via1[vIFR] & irq_bit;
	630	} else if (irq_src == 2) {
	631	return via2[gIFR] & irq_bit;
	632	} else if (irq_src == 7) {
cd713ddc	633	/* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
1da177e4 LT	634	return ~via2[gBufA] & irq_bit;
	635	}
	636	return 0;
	637	}
8852ecd9 LV	638
	639	void via1_set_head(int head)
	640	{
	641	if (head == 0)
	642	via1[vBufA] &= ~VIA1A_vHeadSel;
	643	else
	644	via1[vBufA] \|= VIA1A_vHeadSel;
	645	}
	646	EXPORT_SYMBOL(via1_set_head);