m68k: Mac via cleanup and commentry

No behavioural changes, just cleanups and better documentation.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Finn Thain 2008-11-18 20:45:20 +01:00 committed by Geert Uytterhoeven
parent 40f7f9c1c2
commit 4a973592d6

View File

@ -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. */
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 = 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;
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;
}