/* *	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;void oss_irq(int, void *, struct pt_regs *);void oss_nubus_irq(int, void *, struct pt_regs *);extern void via1_irq(int, void *, struct pt_regs *);extern void 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){	sys_request_irq(OSS_IRQLEV_SCSI, oss_irq, IRQ_FLG_LOCK,			"scsi", (void *) oss);	sys_request_irq(OSS_IRQLEV_IOPSCC, mac_scc_dispatch, IRQ_FLG_LOCK,			"scc", mac_scc_dispatch);	sys_request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, IRQ_FLG_LOCK,			"nubus", (void *) oss);	sys_request_irq(OSS_IRQLEV_SOUND, oss_irq, IRQ_FLG_LOCK,			"sound", (void *) oss);	sys_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. */ void 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;#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? */	}}/* * Nubus IRQ handler, OSS style * * Unlike the VIA/RBV this is on its own autovector interrupt level. */void 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;#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;		}	}}/* * 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;}