via.c

linux-2.6.15.6

		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)
{
	/* don't set nubus_active = 0 here, it kills the Baboon */
	/* interrupt that we've already registered.		*/

	/* unlock nubus transactions */

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

	/* this seems to be an ADB bit on PMU machines */
	/* according to MkLinux.  -- jmt               */

	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
	    (macintosh_config->adb_type != MAC_ADB_PB2)) {
		via2[gBufB] |= 0x02;
	}

	/* disable nubus slot interrupts. */
	if (rbv_present) {
		via2[rSIER] = 0x7F;
		via2[rSIER] = nubus_active | 0x80;
	} else {
		/* These are ADB bits on PMU */
		if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
		   (macintosh_config->adb_type != MAC_ADB_PB2)) {
			switch(macintosh_config->ident)
			{
				case MAC_MODEL_II:
				case MAC_MODEL_IIX:
				case MAC_MODEL_IICX:
				case MAC_MODEL_SE30:
					via2[vBufA] |= 0x3F;
					via2[vDirA] = ~nubus_active | 0xc0;
					break;
				default:
					via2[vBufA] = 0xFF;
					via2[vDirA] = ~nubus_active;
			}
		}
	}
}

/*
 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
 * via6522.c :-), disable/pending masks added.
 *
 * The new interrupt architecture in macints.c takes care of a lot of the
 * gruntwork for us, including tallying the interrupts and calling the
 * handlers on the linked list. All we need to do here is basically generate
 * the machspec interrupt number after clearing the interrupt.
 */

irqreturn_t via1_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	int irq_bit, i;
	unsigned char events, mask;

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

	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
		if (events & irq_bit) {
			via1[vIER] = irq_bit;
			mac_do_irq_list(VIA1_SOURCE_BASE + i, regs);
			via1[vIFR] = irq_bit;
			via1[vIER] = irq_bit | 0x80;
		}

#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);
		mac_do_irq_list(IRQ_MAC_NUBUS, regs);
		via_irq_enable(IRQ_MAC_NUBUS);
	}
#endif
	return IRQ_HANDLED;
}

irqreturn_t via2_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	int irq_bit, i;
	unsigned char events, mask;

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

	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
		if (events & irq_bit) {
			via2[gIER] = irq_bit;
			mac_do_irq_list(VIA2_SOURCE_BASE + i, regs);
			via2[gIFR] = irq_bit | rbv_clear;
			via2[gIER] = irq_bit | 0x80;
		}
	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, struct pt_regs *regs)
{
	int irq_bit, i;
	unsigned char events;

	if (!(events = ~via2[gBufA] & nubus_active))
		return IRQ_NONE;

	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
		if (events & irq_bit) {
			via_irq_disable(NUBUS_SOURCE_BASE + i);
			mac_do_irq_list(NUBUS_SOURCE_BASE + i, regs);
			via_irq_enable(NUBUS_SOURCE_BASE + i);
		}
	}
	return IRQ_HANDLED;
}

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

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

	if (irq_src == 1) {
		via1[vIER] = irq_bit | 0x80;
	} else if (irq_src == 2) {
		/*
		 * Set vPCR for SCSI interrupts (but not on RBV)
		 */
		if ((irq_idx == 0) && !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;
			}
		}
		via2[gIER] = irq_bit | 0x80;
	} else if (irq_src == 7) {
		if (rbv_present) {
			/* enable the slot interrupt. SIER works like IER. */
			via2[rSIER] = IER_SET_BIT(irq_idx);
		} else {
			/* Make sure the bit is an input, to enable the irq */
			/* But not on PowerBooks, that's ADB... */
			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
			   (macintosh_config->adb_type != MAC_ADB_PB2)) {
				switch(macintosh_config->ident)
				{
					case MAC_MODEL_II:
					case MAC_MODEL_IIX:
					case MAC_MODEL_IICX:
					case MAC_MODEL_SE30:
						via2[vDirA] &= (~irq_bit | 0xc0);
						break;
					default:
						via2[vDirA] &= ~irq_bit;
				}
			}
		}
		nubus_active |= irq_bit;
	}
}

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

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

	if (irq_src == 1) {
		via1[vIER] = irq_bit;
	} else if (irq_src == 2) {
		via2[gIER] = irq_bit;
	} else if (irq_src == 7) {
		if (rbv_present) {
			/* disable the slot interrupt.  SIER works like IER. */
			via2[rSIER] = IER_CLR_BIT(irq_idx);
		} else {
			/* disable the nubus irq by changing dir to output */
			/* except on PMU */
			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
			   (macintosh_config->adb_type != MAC_ADB_PB2)) {
				via2[vDirA] |= irq_bit;
			}
		}
		nubus_active &= ~irq_bit;
	}
}

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: hmm.. */
	}
}

/*
 * 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) {
		return ~via2[gBufA] & irq_bit;
	}
	return 0;
}