1 files changed, 301 insertions, 0 deletions
diff --git a/arch/m68k/mac/oss.c b/arch/m68k/mac/oss.c
new file mode 100644
index 00000000000..33354769272
--- /dev/null
+++ b/arch/m68k/mac/oss.c
@@ -0,0 +1,301 @@
+/*
+ *	OSS handling
+ *	Written by Joshua M. Thompson (funaho@jurai.org)
+ *
+ *
+ *	This chip is used in the IIfx in place of VIA #2. It acts like a fancy
+ *	VIA chip with prorammable interrupt levels.
+ *
+ * 990502 (jmt) - Major rewrite for new interrupt architecture as well as some
+ *		  recent insights into OSS operational details.
+ * 990610 (jmt) - Now taking fulll advantage of the OSS. Interrupts are mapped
+ *		  to mostly match the A/UX interrupt scheme supported on the
+ *		  VIA side. Also added support for enabling the ISM irq again
+ *		  since we now have a functional IOP manager.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+
+#include <asm/bootinfo.h>
+#include <asm/machw.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_via.h>
+#include <asm/mac_oss.h>
+
+int oss_present;
+volatile struct mac_oss *oss;
+
+irqreturn_t oss_irq(int, void *, struct pt_regs *);
+irqreturn_t oss_nubus_irq(int, void *, struct pt_regs *);
+
+extern irqreturn_t via1_irq(int, void *, struct pt_regs *);
+extern irqreturn_t mac_scc_dispatch(int, void *, struct pt_regs *);
+
+/*
+ * Initialize the OSS
+ *
+ * The OSS "detection" code is actually in via_init() which is always called
+ * before us. Thus we can count on oss_present being valid on entry.
+ */
+
+void __init oss_init(void)
+{
+	int i;
+
+	if (!oss_present) return;
+
+	oss = (struct mac_oss *) OSS_BASE;
+
+	/* Disable all interrupts. Unlike a VIA it looks like we    */
+	/* do this by setting the source's interrupt level to zero. */
+
+	for (i = 0; i <= OSS_NUM_SOURCES; i++) {
+		oss->irq_level[i] = OSS_IRQLEV_DISABLED;
+	}
+	/* If we disable VIA1 here, we never really handle it... */
+	oss->irq_level[OSS_VIA1] = OSS_IRQLEV_VIA1;
+}
+
+/*
+ * Register the OSS and NuBus interrupt dispatchers.
+ */
+
+void __init oss_register_interrupts(void)
+{
+	cpu_request_irq(OSS_IRQLEV_SCSI, oss_irq, IRQ_FLG_LOCK,
+			"scsi", (void *) oss);
+	cpu_request_irq(OSS_IRQLEV_IOPSCC, mac_scc_dispatch, IRQ_FLG_LOCK,
+			"scc", mac_scc_dispatch);
+	cpu_request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, IRQ_FLG_LOCK,
+			"nubus", (void *) oss);
+	cpu_request_irq(OSS_IRQLEV_SOUND, oss_irq, IRQ_FLG_LOCK,
+			"sound", (void *) oss);
+	cpu_request_irq(OSS_IRQLEV_VIA1, via1_irq, IRQ_FLG_LOCK,
+			"via1", (void *) via1);
+}
+
+/*
+ * Initialize OSS for Nubus access
+ */
+
+void __init oss_nubus_init(void)
+{
+}
+
+/*
+ * Handle miscellaneous OSS interrupts. Right now that's just sound
+ * and SCSI; everything else is routed to its own autovector IRQ.
+ */
+
+irqreturn_t oss_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+	int events;
+
+	events = oss->irq_pending & (OSS_IP_SOUND|OSS_IP_SCSI);
+	if (!events)
+		return IRQ_NONE;
+
+#ifdef DEBUG_IRQS
+	if ((console_loglevel == 10) && !(events & OSS_IP_SCSI)) {
+		printk("oss_irq: irq %d events = 0x%04X\n", irq,
+			(int) oss->irq_pending);
+	}
+#endif
+	/* FIXME: how do you clear a pending IRQ?    */
+
+	if (events & OSS_IP_SOUND) {
+		/* FIXME: call sound handler */
+		oss->irq_pending &= ~OSS_IP_SOUND;
+	} else if (events & OSS_IP_SCSI) {
+		oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED;
+		mac_do_irq_list(IRQ_MAC_SCSI, regs);
+		oss->irq_pending &= ~OSS_IP_SCSI;
+		oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI;
+	} else {
+		/* FIXME: error check here? */
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * Nubus IRQ handler, OSS style
+ *
+ * Unlike the VIA/RBV this is on its own autovector interrupt level.
+ */
+
+irqreturn_t oss_nubus_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+	int events, irq_bit, i;
+
+	events = oss->irq_pending & OSS_IP_NUBUS;
+	if (!events)
+		return IRQ_NONE;
+
+#ifdef DEBUG_NUBUS_INT
+	if (console_loglevel > 7) {
+		printk("oss_nubus_irq: events = 0x%04X\n", events);
+	}
+#endif
+	/* There are only six slots on the OSS, not seven */
+
+	for (i = 0, irq_bit = 1 ; i < 6 ; i++, irq_bit <<= 1) {
+		if (events & irq_bit) {
+			oss->irq_level[i] = OSS_IRQLEV_DISABLED;
+			mac_do_irq_list(NUBUS_SOURCE_BASE + i, regs);
+			oss->irq_pending &= ~irq_bit;
+			oss->irq_level[i] = OSS_IRQLEV_NUBUS;
+		}
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * Enable an OSS interrupt
+ *
+ * It looks messy but it's rather straightforward. The switch() statement
+ * just maps the machspec interrupt numbers to the right OSS interrupt
+ * source (if the OSS handles that interrupt) and then sets the interrupt
+ * level for that source to nonzero, thus enabling the interrupt.
+ */
+
+void oss_irq_enable(int irq) {
+#ifdef DEBUG_IRQUSE
+	printk("oss_irq_enable(%d)\n", irq);
+#endif
+	switch(irq) {
+		case IRQ_SCC:
+		case IRQ_SCCA:
+		case IRQ_SCCB:
+			oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_IOPSCC;
+			break;
+		case IRQ_MAC_ADB:
+			oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_IOPISM;
+			break;
+		case IRQ_MAC_SCSI:
+			oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI;
+			break;
+		case IRQ_NUBUS_9:
+		case IRQ_NUBUS_A:
+		case IRQ_NUBUS_B:
+		case IRQ_NUBUS_C:
+		case IRQ_NUBUS_D:
+		case IRQ_NUBUS_E:
+			irq -= NUBUS_SOURCE_BASE;
+			oss->irq_level[irq] = OSS_IRQLEV_NUBUS;
+			break;
+#ifdef DEBUG_IRQUSE
+		default:
+			printk("%s unknown irq %d\n",__FUNCTION__, irq);
+			break;
+#endif
+	}
+}
+
+/*
+ * Disable an OSS interrupt
+ *
+ * Same as above except we set the source's interrupt level to zero,
+ * to disable the interrupt.
+ */
+
+void oss_irq_disable(int irq) {
+#ifdef DEBUG_IRQUSE
+	printk("oss_irq_disable(%d)\n", irq);
+#endif
+	switch(irq) {
+		case IRQ_SCC:
+		case IRQ_SCCA:
+		case IRQ_SCCB:
+			oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_DISABLED;
+			break;
+		case IRQ_MAC_ADB:
+			oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_DISABLED;
+			break;
+		case IRQ_MAC_SCSI:
+			oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED;
+			break;
+		case IRQ_NUBUS_9:
+		case IRQ_NUBUS_A:
+		case IRQ_NUBUS_B:
+		case IRQ_NUBUS_C:
+		case IRQ_NUBUS_D:
+		case IRQ_NUBUS_E:
+			irq -= NUBUS_SOURCE_BASE;
+			oss->irq_level[irq] = OSS_IRQLEV_DISABLED;
+			break;
+#ifdef DEBUG_IRQUSE
+		default:
+			printk("%s unknown irq %d\n", __FUNCTION__, irq);
+			break;
+#endif
+	}
+}
+
+/*
+ * Clear an OSS interrupt
+ *
+ * Not sure if this works or not but it's the only method I could
+ * think of based on the contents of the mac_oss structure.
+ */
+
+void oss_irq_clear(int irq) {
+	/* FIXME: how to do this on OSS? */
+	switch(irq) {
+		case IRQ_SCC:
+		case IRQ_SCCA:
+		case IRQ_SCCB:
+			oss->irq_pending &= ~OSS_IP_IOPSCC;
+			break;
+		case IRQ_MAC_ADB:
+			oss->irq_pending &= ~OSS_IP_IOPISM;
+			break;
+		case IRQ_MAC_SCSI:
+			oss->irq_pending &= ~OSS_IP_SCSI;
+			break;
+		case IRQ_NUBUS_9:
+		case IRQ_NUBUS_A:
+		case IRQ_NUBUS_B:
+		case IRQ_NUBUS_C:
+		case IRQ_NUBUS_D:
+		case IRQ_NUBUS_E:
+			irq -= NUBUS_SOURCE_BASE;
+			oss->irq_pending &= ~(1 << irq);
+			break;
+	}
+}
+
+/*
+ * Check to see if a specific OSS interrupt is pending
+ */
+
+int oss_irq_pending(int irq)
+{
+	switch(irq) {
+		case IRQ_SCC:
+		case IRQ_SCCA:
+		case IRQ_SCCB:
+			return oss->irq_pending & OSS_IP_IOPSCC;
+			break;
+		case IRQ_MAC_ADB:
+			return oss->irq_pending & OSS_IP_IOPISM;
+			break;
+		case IRQ_MAC_SCSI:
+			return oss->irq_pending & OSS_IP_SCSI;
+			break;
+		case IRQ_NUBUS_9:
+		case IRQ_NUBUS_A:
+		case IRQ_NUBUS_B:
+		case IRQ_NUBUS_C:
+		case IRQ_NUBUS_D:
+		case IRQ_NUBUS_E:
+			irq -= NUBUS_SOURCE_BASE;
+			return oss->irq_pending & (1 << irq);
+			break;
+	}
+	return 0;
+}