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-rw-r--r--arch/m68k/mac/via.c329
1 files changed, 151 insertions, 178 deletions
diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c
index e71166daec6..2d85662715f 100644
--- a/arch/m68k/mac/via.c
+++ b/arch/m68k/mac/via.c
@@ -28,6 +28,7 @@
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/irq.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
@@ -62,27 +63,50 @@ 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 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
- * 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.
+
+/*
+ * On Macs with a genuine VIA chip there is no way to mask an individual slot
+ * interrupt. This limitation also seems to apply to VIA clone logic cores in
+ * Quadra-like ASICs. (RBV and OSS machines don't have this limitation.)
+ *
+ * We used to fake it by configuring the relevent VIA pin as an output
+ * (to mask the interrupt) or input (to unmask). That scheme did not work on
+ * (at least) the Quadra 700. A NuBus card's /NMRQ signal is an open-collector
+ * circuit (see Designing Cards and Drivers for Macintosh II and Macintosh SE,
+ * p. 10-11 etc) but VIA outputs are not (see datasheet).
+ *
+ * Driving these outputs high must cause the VIA to source current and the
+ * card to sink current when it asserts /NMRQ. Current will flow but the pin
+ * voltage is uncertain and so the /NMRQ condition may still cause a transition
+ * at the VIA2 CA1 input (which explains the lost interrupts). A side effect
+ * is that a disabled slot IRQ can never be tested as pending or not.
+ *
+ * Driving these outputs low doesn't work either. All the slot /NMRQ lines are
+ * (active low) OR'd together to generate the CA1 (aka "SLOTS") interrupt (see
+ * The Guide To Macintosh Family Hardware, 2nd edition p. 167). If we drive a
+ * disabled /NMRQ line low, the falling edge immediately triggers a CA1
+ * interrupt and all slot interrupts after that will generate no transition
+ * and therefore no interrupt, even after being re-enabled.
+ *
+ * So we make the VIA port A I/O lines inputs and use nubus_disabled to keep
+ * track of their states. When any slot IRQ becomes disabled we mask the CA1
+ * umbrella interrupt. Only when all slot IRQs become enabled do we unmask
+ * the CA1 interrupt. It must remain enabled even when cards have no interrupt
+ * handler registered. Drivers must therefore disable a slot interrupt at the
+ * device before they call free_irq (like shared and autovector interrupts).
+ *
+ * There is also a related problem when MacOS is used to boot Linux. A network
+ * card brought up by a MacOS driver may raise an interrupt while Linux boots.
+ * This can be fatal since it can't be handled until the right driver loads
+ * (if such a driver exists at all). Apparently related to this hardware
+ * limitation, "Designing Cards and Drivers", p. 9-8, says that a slot
+ * interrupt with no driver would crash MacOS (the book was written before
+ * the appearance of Macs with RBV or OSS).
*/
+
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);
/*
* Initialize the VIAs
@@ -102,7 +126,7 @@ void __init via_init(void)
/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
- case MAC_VIA_IIci:
+ case MAC_VIA_IICI:
via1 = (void *) VIA1_BASE;
if (macintosh_config->ident == MAC_MODEL_IIFX) {
via2 = NULL;
@@ -199,38 +223,17 @@ void __init via_init(void)
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;
- }
+ if ((macintosh_config->via_type == MAC_VIA_QUADRA) &&
+ (macintosh_config->adb_type != MAC_ADB_PB1) &&
+ (macintosh_config->adb_type != MAC_ADB_PB2) &&
+ (macintosh_config->ident != MAC_MODEL_C660) &&
+ (macintosh_config->ident != MAC_MODEL_Q840)) {
+ via_alt_mapping = 1;
+ via1[vDirB] |= 0x40;
+ via1[vBufB] &= ~0x40;
+ } else {
+ via_alt_mapping = 0;
+ }
/*
* Now initialize VIA2. For RBV we just kill all interrupts;
@@ -250,22 +253,28 @@ void __init via_init(void)
via2[vACR] &= ~0x03; /* disable port A & B latches */
}
+ /* Everything below this point is VIA2 only... */
+
+ if (rbv_present)
+ return;
+
/*
- * Set vPCR for control line interrupts (but not on RBV)
+ * Set vPCR for control line interrupts.
+ *
+ * CA1 (SLOTS IRQ), CB1 (ASC IRQ): negative edge trigger.
+ *
+ * Macs with ESP SCSI have a negative edge triggered SCSI interrupt.
+ * Testing reveals that PowerBooks do too. However, the SE/30
+ * schematic diagram shows an active high NCR5380 IRQ line.
*/
- 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;
- }
+
+ pr_debug("VIA2 vPCR is 0x%02X\n", via2[vPCR]);
+ if (macintosh_config->via_type == MAC_VIA_II) {
+ /* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, pos. edge */
+ via2[vPCR] = 0x66;
+ } else {
+ /* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, neg. edge */
+ via2[vPCR] = 0x22;
}
}
@@ -281,40 +290,11 @@ void __init via_init_clock(irq_handler_t func)
via1[vT1CL] = MAC_CLOCK_LOW;
via1[vT1CH] = MAC_CLOCK_HIGH;
- if (request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func))
+ if (request_irq(IRQ_MAC_TIMER_1, func, 0, "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 (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.
*/
@@ -409,34 +389,55 @@ void __init via_nubus_init(void)
via2[gBufB] |= 0x02;
}
- /* Disable all the slot interrupts (where possible). */
+ /*
+ * Disable the slot interrupts. On some hardware that's not possible.
+ * On some hardware it's unclear what all of these I/O lines do.
+ */
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;
- }
+ case MAC_VIA_QUADRA:
+ pr_debug("VIA2 vDirA is 0x%02X\n", via2[vDirA]);
break;
- case MAC_VIA_IIci:
+ case MAC_VIA_IICI:
/* RBV. Disable all the slot interrupts. SIER works like IER. */
via2[rSIER] = 0x7F;
break;
+ }
+}
+
+void via_nubus_irq_startup(int irq)
+{
+ int irq_idx = IRQ_IDX(irq);
+
+ switch (macintosh_config->via_type) {
+ case MAC_VIA_II:
case MAC_VIA_QUADRA:
- /* Disable the inactive slot interrupts by making those lines outputs. */
- if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
- (macintosh_config->adb_type != MAC_ADB_PB2)) {
- via2[vBufA] |= 0x7F;
- via2[vDirA] |= 0x7F;
+ /* Make the port A line an input. Probably redundant. */
+ if (macintosh_config->via_type == MAC_VIA_II) {
+ /* The top two bits are RAM size outputs. */
+ via2[vDirA] &= 0xC0 | ~(1 << irq_idx);
+ } else {
+ /* Allow NuBus slots 9 through F. */
+ via2[vDirA] &= 0x80 | ~(1 << irq_idx);
}
+ /* fall through */
+ case MAC_VIA_IICI:
+ via_irq_enable(irq);
+ break;
+ }
+}
+
+void via_nubus_irq_shutdown(int irq)
+{
+ switch (macintosh_config->via_type) {
+ case MAC_VIA_II:
+ case MAC_VIA_QUADRA:
+ /* Ensure that the umbrella CA1 interrupt remains enabled. */
+ via_irq_enable(irq);
+ break;
+ case MAC_VIA_IICI:
+ via_irq_disable(irq);
break;
}
}
@@ -446,48 +447,46 @@ void __init via_nubus_init(void)
* via6522.c :-), disable/pending masks added.
*/
-irqreturn_t via1_irq(int irq, void *dev_id)
+void via1_irq(unsigned int irq, struct irq_desc *desc)
{
int irq_num;
unsigned char irq_bit, events;
events = via1[vIFR] & via1[vIER] & 0x7F;
if (!events)
- return IRQ_NONE;
+ return;
irq_num = VIA1_SOURCE_BASE;
irq_bit = 1;
do {
if (events & irq_bit) {
via1[vIFR] = irq_bit;
- m68k_handle_int(irq_num);
+ generic_handle_irq(irq_num);
}
++irq_num;
irq_bit <<= 1;
} while (events >= irq_bit);
- return IRQ_HANDLED;
}
-irqreturn_t via2_irq(int irq, void *dev_id)
+static void via2_irq(unsigned int irq, struct irq_desc *desc)
{
int irq_num;
unsigned char irq_bit, events;
events = via2[gIFR] & via2[gIER] & 0x7F;
if (!events)
- return IRQ_NONE;
+ return;
irq_num = VIA2_SOURCE_BASE;
irq_bit = 1;
do {
if (events & irq_bit) {
via2[gIFR] = irq_bit | rbv_clear;
- m68k_handle_int(irq_num);
+ generic_handle_irq(irq_num);
}
++irq_num;
irq_bit <<= 1;
} while (events >= irq_bit);
- return IRQ_HANDLED;
}
/*
@@ -495,7 +494,7 @@ irqreturn_t via2_irq(int irq, void *dev_id)
* VIA2 dispatcher as a fast interrupt handler.
*/
-irqreturn_t via_nubus_irq(int irq, void *dev_id)
+void via_nubus_irq(unsigned int irq, struct irq_desc *desc)
{
int slot_irq;
unsigned char slot_bit, events;
@@ -506,7 +505,7 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
else
events &= ~via2[vDirA];
if (!events)
- return IRQ_NONE;
+ return;
do {
slot_irq = IRQ_NUBUS_F;
@@ -514,7 +513,7 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
do {
if (events & slot_bit) {
events &= ~slot_bit;
- m68k_handle_int(slot_irq);
+ generic_handle_irq(slot_irq);
}
--slot_irq;
slot_bit >>= 1;
@@ -528,7 +527,24 @@ irqreturn_t via_nubus_irq(int irq, void *dev_id)
else
events &= ~via2[vDirA];
} while (events);
- return IRQ_HANDLED;
+}
+
+/*
+ * Register the interrupt dispatchers for VIA or RBV machines only.
+ */
+
+void __init via_register_interrupts(void)
+{
+ if (via_alt_mapping) {
+ /* software interrupt */
+ irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
+ /* via1 interrupt */
+ irq_set_chained_handler(IRQ_AUTO_6, via1_irq);
+ } else {
+ irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
+ }
+ irq_set_chained_handler(IRQ_AUTO_2, via2_irq);
+ irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq);
}
void via_irq_enable(int irq) {
@@ -547,25 +563,18 @@ void via_irq_enable(int irq) {
} else if (irq_src == 7) {
switch (macintosh_config->via_type) {
case MAC_VIA_II:
+ case MAC_VIA_QUADRA:
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:
+ case MAC_VIA_IICI:
/* On RBV, enable the slot interrupt.
* SIER works like IER.
*/
via2[rSIER] = IER_SET_BIT(irq_idx);
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) &&
- (macintosh_config->adb_type != MAC_ADB_PB2))
- via2[vDirA] &= ~(1 << irq_idx);
- break;
}
}
}
@@ -585,60 +594,18 @@ void via_irq_disable(int irq) {
} else if (irq_src == 7) {
switch (macintosh_config->via_type) {
case MAC_VIA_II:
+ case MAC_VIA_QUADRA:
nubus_disabled |= 1 << irq_idx;
if (nubus_disabled)
via2[gIER] = IER_CLR_BIT(1);
break;
- case MAC_VIA_IIci:
+ case MAC_VIA_IICI:
via2[rSIER] = IER_CLR_BIT(irq_idx);
break;
- case MAC_VIA_QUADRA:
- if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
- (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) {
- /* 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)
@@ -647,3 +614,9 @@ void via1_set_head(int head)
via1[vBufA] |= VIA1A_vHeadSel;
}
EXPORT_SYMBOL(via1_set_head);
+
+int via2_scsi_drq_pending(void)
+{
+ return via2[gIFR] & (1 << IRQ_IDX(IRQ_MAC_SCSIDRQ));
+}
+EXPORT_SYMBOL(via2_scsi_drq_pending);
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