linux/arch/m68k/mac/via.c

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/*
* 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>
#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
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
* 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 *);
/*
* 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, IRQ_FLG_LOCK, "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,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
(void *) via1))
pr_err("Couldn't register %s interrupt\n", "software");
if (request_irq(IRQ_AUTO_6, via1_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
(void *) via1))
pr_err("Couldn't register %s interrupt\n", "via1");
} else {
if (request_irq(IRQ_AUTO_1, via1_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
(void *) via1))
pr_err("Couldn't register %s interrupt\n", "via1");
}
if (request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"via2", (void *) via2))
pr_err("Couldn't register %s interrupt\n", "via2");
if (!psc_present) {
if (request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
"scc", mac_scc_dispatch))
pr_err("Couldn't register %s interrupt\n", "scc");
}
if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "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;
}
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
/* 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;
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
break;
case MAC_VIA_QUADRA:
/* Disable the inactive slot interrupts by making those lines outputs. */
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
(macintosh_config->adb_type != MAC_ADB_PB2)) {
via2[vBufA] |= 0x7F;
via2[vDirA] |= 0x7F;
}
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
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);
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
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
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
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
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) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
via1[vIER] = IER_SET_BIT(irq_idx);
} else if (irq_src == 2) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
via2[gIER] = IER_SET_BIT(irq_idx);
} else if (irq_src == 7) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
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);
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
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) &&
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
(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) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
via1[vIER] = IER_CLR_BIT(irq_idx);
} else if (irq_src == 2) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
via2[gIER] = IER_CLR_BIT(irq_idx);
} else if (irq_src == 7) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
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);
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
break;
case MAC_VIA_QUADRA:
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
(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) {
m68k: Mac nubus IRQ fixes (plan E) Some Macs lack a slot interrupt enable register. So the existing code makes disabled and unregistered slot IRQ lines outputs set high. This seems to work on quadras, but does not work on genuine VIAs (perhaps the card still succeeds in pulling the line low, or perhaps because this increases the settle time on the port A input, meaning that the CA1 IRQ could fire before the slot line reads active). Because of this, the nubus_active flags were used to mask IRQs, which is actually worse than the problem it tries to solve. Any interrupt masked by nubus_active will remain asserted and prevent further transitions on CA1. And so the nubus gets wedged regardless of hardware (emulated VIA ASIC, real VIA chip or RBV). The best solution to this hardware limitation of genuine VIAs is to disable the umbrella SLOTS IRQ when disabling a slot on those machines. Unfortunately, this means all slot IRQs get disabled when any slot IRQ is disabled. But it is only a problem when there's more than 1 device using nubus interrupts. Another potential problem for genuine VIAs is an unregistered nubus IRQ. Eventually it will be possible to enable the CA1 interrupt by installing its handler only _after_ all nubus drivers have loaded but _before_ the kernel needs them, at which time this last problem can be fixed. For now it can be worked around: - disable MacOS extensions - don't boot MacOS (use the Emile bootloader instead) - get the bootloaders to disable ROM drivers (Penguin does this for video cards already, don't know about Emile) - physically remove unsupported cards Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01 20:32:57 +00:00
/* 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);