Commit 4a973592 authored by Finn Thain's avatar Finn Thain Committed by Geert Uytterhoeven
Browse files

m68k: Mac via cleanup and commentry 



No behavioural changes, just cleanups and better documentation.

Signed-off-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent 40f7f9c1

arch/m68k/mac/via.c

+32 −47
Original line number Diff line number Diff line
@@ -37,10 +37,6 @@ 
#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;

int via_alt_mapping;

EXPORT_SYMBOL(via_alt_mapping);
@@ -66,7 +62,7 @@ static int gIER,gIFR,gBufA,gBufB; 
#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

/* 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
@@ -180,7 +176,7 @@ void __init via_init(void) 
	via1[vT1CH] = 0;

	via1[vT2CL] = 0;

	via1[vT2CH] = 0;

	via1[vACR] &= 0x3F;

	via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */

	via1[vACR] &= ~0x03; /* disable port A & B latches */



	/*
@@ -203,40 +199,41 @@ void __init via_init(void) 


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



	if (oss_present) return;

	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. */



	via_alt_mapping = 0;

	if (macintosh_config->via_type == MAC_VIA_QUADRA)

		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:

		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;

		default:

			via_alt_mapping = 0;

			break;

		}

#else

	via_alt_mapping = 0;

#endif



	/*

	 * Now initialize VIA2. For RBV we just kill all interrupts;
@@ -252,14 +249,17 @@ void __init via_init(void) 
		via2[vT1CH] = 0;

		via2[vT2CL] = 0;

		via2[vT2CH] = 0;

		via2[vACR] &= 0x3F;

		via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */

		via2[vACR] &= ~0x03; /* disable port A & B latches */

	}



	/*

	 * Set vPCR for SCSI interrupts (but not on RBV)

	 * 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 */
@@ -466,21 +466,6 @@ irqreturn_t via1_irq(int irq, void *dev_id) 
		++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;

}