m68k: Mac IRQ prep
Make sure that there are no slot IRQs asserted before leaving the nubus
handler. If there are and we don't then the nubus gets wedged because this
prevents a CA1 transition, which means no more nubus IRQs.
Make the interrupt dispatch loops terminate sooner.
Explicitly initialise the VIA latches to make the code more easily understood.
Also some cleanups.
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>
diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c
index 21b0318..0c1cc45 100644
--- a/arch/m68k/mac/via.c
+++ b/arch/m68k/mac/via.c
@@ -13,6 +13,10 @@
* 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)
*
@@ -37,7 +41,7 @@
/* 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,via_alt_mapping;
+int rbv_present, via_alt_mapping;
__u8 rbv_clear;
/*
@@ -138,11 +142,11 @@
printk(KERN_INFO "VIA2 at %p is ", via2);
if (rbv_present) {
- printk(KERN_INFO "an RBV\n");
+ printk("an RBV\n");
} else if (oss_present) {
- printk(KERN_INFO "an OSS\n");
+ printk("an OSS\n");
} else {
- printk(KERN_INFO "a 6522 or clone\n");
+ printk("a 6522 or clone\n");
}
#ifdef DEBUG_VIA
@@ -163,6 +167,7 @@
via1[vT2CL] = 0;
via1[vT2CH] = 0;
via1[vACR] &= 0x3F;
+ via1[vACR] &= ~0x03; /* disable port A & B latches */
/*
* SE/30: disable video IRQ
@@ -234,6 +239,22 @@
via2[vT2CL] = 0;
via2[vT2CH] = 0;
via2[vACR] &= 0x3F;
+ via2[vACR] &= ~0x03; /* disable port A & B latches */
+ }
+
+ /*
+ * Set vPCR for SCSI interrupts (but not on RBV)
+ */
+ if (!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;
+ }
}
}
@@ -367,19 +388,14 @@
/* 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)) {
+ /* 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;
}
@@ -420,20 +436,25 @@
irqreturn_t via1_irq(int irq, void *dev_id)
{
- int irq_bit, i;
- unsigned char events, mask;
+ int irq_num;
+ unsigned char irq_bit, events;
- mask = via1[vIER] & 0x7F;
- if (!(events = via1[vIFR] & mask))
+ events = via1[vIFR] & via1[vIER] & 0x7F;
+ if (!events)
return IRQ_NONE;
- for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
+ irq_num = VIA1_SOURCE_BASE;
+ irq_bit = 1;
+ do {
if (events & irq_bit) {
via1[vIER] = irq_bit;
via1[vIFR] = irq_bit;
- m68k_handle_int(VIA1_SOURCE_BASE + i);
+ m68k_handle_int(irq_num);
via1[vIER] = irq_bit | 0x80;
}
+ ++irq_num;
+ irq_bit <<= 1;
+ } while (events >= irq_bit);
#if 0 /* freakin' pmu is doing weird stuff */
if (!oss_present) {
@@ -454,20 +475,25 @@
irqreturn_t via2_irq(int irq, void *dev_id)
{
- int irq_bit, i;
- unsigned char events, mask;
+ int irq_num;
+ unsigned char irq_bit, events;
- mask = via2[gIER] & 0x7F;
- if (!(events = via2[gIFR] & mask))
+ events = via2[gIFR] & via2[gIER] & 0x7F;
+ if (!events)
return IRQ_NONE;
- for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
+ irq_num = VIA2_SOURCE_BASE;
+ irq_bit = 1;
+ do {
if (events & irq_bit) {
via2[gIER] = irq_bit;
via2[gIFR] = irq_bit | rbv_clear;
- m68k_handle_int(VIA2_SOURCE_BASE + i);
+ m68k_handle_int(irq_num);
via2[gIER] = irq_bit | 0x80;
}
+ ++irq_num;
+ irq_bit <<= 1;
+ } while (events >= irq_bit);
return IRQ_HANDLED;
}
@@ -478,19 +504,37 @@
irqreturn_t via_nubus_irq(int irq, void *dev_id)
{
- int irq_bit, i;
- unsigned char events;
+ int slot_irq;
+ unsigned char slot_bit, events;
- if (!(events = ~via2[gBufA] & nubus_active))
+ events = ~via2[gBufA] & 0x7F;
+ if (rbv_present)
+ events &= via2[rSIER];
+ else
+ events &= nubus_active;
+ if (!events)
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);
- m68k_handle_int(NUBUS_SOURCE_BASE + i);
- via_irq_enable(NUBUS_SOURCE_BASE + i);
- }
- }
+ 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
+ events &= nubus_active;
+ } while (events);
return IRQ_HANDLED;
}
@@ -506,20 +550,6 @@
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) {
nubus_active |= irq_bit;
@@ -557,9 +587,9 @@
#endif
if (irq_src == 1) {
- via1[vIER] = irq_bit;
+ via1[vIER] = irq_bit & 0x7F;
} else if (irq_src == 2) {
- via2[gIER] = irq_bit;
+ via2[gIER] = irq_bit & 0x7F;
} else if (irq_src == 7) {
if (rbv_present) {
/* disable the slot interrupt. SIER works like IER. */
@@ -586,7 +616,9 @@
} else if (irq_src == 2) {
via2[gIFR] = irq_bit | rbv_clear;
} else if (irq_src == 7) {
- /* FIXME: hmm.. */
+ /* FIXME: There is no way to clear an individual nubus slot
+ * IRQ flag, other than getting the device to do it.
+ */
}
}
@@ -606,6 +638,7 @@
} else if (irq_src == 2) {
return via2[gIFR] & irq_bit;
} else if (irq_src == 7) {
+ /* FIXME: this can't work while a slot irq is disabled! */
return ~via2[gBufA] & irq_bit;
}
return 0;