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https://github.com/torvalds/linux
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67dfb153a3
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>
306 lines
6.9 KiB
C
306 lines
6.9 KiB
C
/*
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* OSS handling
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* Written by Joshua M. Thompson (funaho@jurai.org)
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*
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*
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* This chip is used in the IIfx in place of VIA #2. It acts like a fancy
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* VIA chip with prorammable interrupt levels.
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*
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* 990502 (jmt) - Major rewrite for new interrupt architecture as well as some
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* recent insights into OSS operational details.
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* 990610 (jmt) - Now taking fulll advantage of the OSS. Interrupts are mapped
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* to mostly match the A/UX interrupt scheme supported on the
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* VIA side. Also added support for enabling the ISM irq again
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* since we now have a functional IOP manager.
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <asm/bootinfo.h>
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#include <asm/machw.h>
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#include <asm/macintosh.h>
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#include <asm/macints.h>
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#include <asm/mac_via.h>
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#include <asm/mac_oss.h>
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int oss_present;
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volatile struct mac_oss *oss;
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irqreturn_t oss_irq(int, void *);
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irqreturn_t oss_nubus_irq(int, void *);
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extern irqreturn_t via1_irq(int, void *);
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extern irqreturn_t mac_scc_dispatch(int, void *);
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/*
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* Initialize the OSS
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*
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* The OSS "detection" code is actually in via_init() which is always called
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* before us. Thus we can count on oss_present being valid on entry.
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*/
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void __init oss_init(void)
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{
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int i;
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if (!oss_present) return;
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oss = (struct mac_oss *) OSS_BASE;
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/* Disable all interrupts. Unlike a VIA it looks like we */
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/* do this by setting the source's interrupt level to zero. */
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for (i = 0; i <= OSS_NUM_SOURCES; i++) {
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oss->irq_level[i] = OSS_IRQLEV_DISABLED;
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}
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/* If we disable VIA1 here, we never really handle it... */
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oss->irq_level[OSS_VIA1] = OSS_IRQLEV_VIA1;
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}
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/*
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* Register the OSS and NuBus interrupt dispatchers.
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*/
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void __init oss_register_interrupts(void)
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{
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request_irq(OSS_IRQLEV_SCSI, oss_irq, IRQ_FLG_LOCK,
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"scsi", (void *) oss);
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request_irq(OSS_IRQLEV_IOPSCC, mac_scc_dispatch, IRQ_FLG_LOCK,
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"scc", mac_scc_dispatch);
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request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, IRQ_FLG_LOCK,
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"nubus", (void *) oss);
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request_irq(OSS_IRQLEV_SOUND, oss_irq, IRQ_FLG_LOCK,
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"sound", (void *) oss);
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request_irq(OSS_IRQLEV_VIA1, via1_irq, IRQ_FLG_LOCK,
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"via1", (void *) via1);
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}
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/*
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* Initialize OSS for Nubus access
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*/
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void __init oss_nubus_init(void)
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{
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}
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/*
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* Handle miscellaneous OSS interrupts. Right now that's just sound
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* and SCSI; everything else is routed to its own autovector IRQ.
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*/
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irqreturn_t oss_irq(int irq, void *dev_id)
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{
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int events;
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events = oss->irq_pending & (OSS_IP_SOUND|OSS_IP_SCSI);
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if (!events)
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return IRQ_NONE;
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#ifdef DEBUG_IRQS
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if ((console_loglevel == 10) && !(events & OSS_IP_SCSI)) {
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printk("oss_irq: irq %d events = 0x%04X\n", irq,
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(int) oss->irq_pending);
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}
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#endif
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/* FIXME: how do you clear a pending IRQ? */
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if (events & OSS_IP_SOUND) {
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oss->irq_pending &= ~OSS_IP_SOUND;
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/* FIXME: call sound handler */
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} else if (events & OSS_IP_SCSI) {
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oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED;
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oss->irq_pending &= ~OSS_IP_SCSI;
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m68k_handle_int(IRQ_MAC_SCSI);
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oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI;
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} else {
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/* FIXME: error check here? */
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}
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return IRQ_HANDLED;
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}
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/*
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* Nubus IRQ handler, OSS style
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*
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* Unlike the VIA/RBV this is on its own autovector interrupt level.
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*/
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irqreturn_t oss_nubus_irq(int irq, void *dev_id)
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{
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int events, irq_bit, i;
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events = oss->irq_pending & OSS_IP_NUBUS;
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if (!events)
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return IRQ_NONE;
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#ifdef DEBUG_NUBUS_INT
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if (console_loglevel > 7) {
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printk("oss_nubus_irq: events = 0x%04X\n", events);
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}
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#endif
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/* There are only six slots on the OSS, not seven */
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i = 6;
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irq_bit = 0x40;
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do {
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--i;
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irq_bit >>= 1;
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if (events & irq_bit) {
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oss->irq_level[i] = OSS_IRQLEV_DISABLED;
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oss->irq_pending &= ~irq_bit;
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m68k_handle_int(NUBUS_SOURCE_BASE + i);
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oss->irq_level[i] = OSS_IRQLEV_NUBUS;
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}
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} while(events & (irq_bit - 1));
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return IRQ_HANDLED;
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}
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/*
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* Enable an OSS interrupt
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*
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* It looks messy but it's rather straightforward. The switch() statement
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* just maps the machspec interrupt numbers to the right OSS interrupt
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* source (if the OSS handles that interrupt) and then sets the interrupt
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* level for that source to nonzero, thus enabling the interrupt.
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*/
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void oss_irq_enable(int irq) {
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#ifdef DEBUG_IRQUSE
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printk("oss_irq_enable(%d)\n", irq);
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#endif
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switch(irq) {
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case IRQ_SCC:
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case IRQ_SCCA:
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case IRQ_SCCB:
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oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_IOPSCC;
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break;
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case IRQ_MAC_ADB:
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oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_IOPISM;
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break;
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case IRQ_MAC_SCSI:
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oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI;
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break;
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case IRQ_NUBUS_9:
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case IRQ_NUBUS_A:
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case IRQ_NUBUS_B:
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case IRQ_NUBUS_C:
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case IRQ_NUBUS_D:
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case IRQ_NUBUS_E:
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irq -= NUBUS_SOURCE_BASE;
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oss->irq_level[irq] = OSS_IRQLEV_NUBUS;
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break;
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#ifdef DEBUG_IRQUSE
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default:
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printk("%s unknown irq %d\n",__FUNCTION__, irq);
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break;
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#endif
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}
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}
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/*
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* Disable an OSS interrupt
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*
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* Same as above except we set the source's interrupt level to zero,
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* to disable the interrupt.
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*/
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void oss_irq_disable(int irq) {
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#ifdef DEBUG_IRQUSE
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printk("oss_irq_disable(%d)\n", irq);
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#endif
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switch(irq) {
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case IRQ_SCC:
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case IRQ_SCCA:
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case IRQ_SCCB:
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oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_DISABLED;
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break;
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case IRQ_MAC_ADB:
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oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_DISABLED;
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break;
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case IRQ_MAC_SCSI:
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oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED;
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break;
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case IRQ_NUBUS_9:
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case IRQ_NUBUS_A:
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case IRQ_NUBUS_B:
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case IRQ_NUBUS_C:
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case IRQ_NUBUS_D:
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case IRQ_NUBUS_E:
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irq -= NUBUS_SOURCE_BASE;
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oss->irq_level[irq] = OSS_IRQLEV_DISABLED;
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break;
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#ifdef DEBUG_IRQUSE
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default:
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printk("%s unknown irq %d\n", __FUNCTION__, irq);
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break;
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#endif
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}
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}
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/*
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* Clear an OSS interrupt
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*
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* Not sure if this works or not but it's the only method I could
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* think of based on the contents of the mac_oss structure.
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*/
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void oss_irq_clear(int irq) {
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/* FIXME: how to do this on OSS? */
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switch(irq) {
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case IRQ_SCC:
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case IRQ_SCCA:
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case IRQ_SCCB:
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oss->irq_pending &= ~OSS_IP_IOPSCC;
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break;
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case IRQ_MAC_ADB:
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oss->irq_pending &= ~OSS_IP_IOPISM;
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break;
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case IRQ_MAC_SCSI:
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oss->irq_pending &= ~OSS_IP_SCSI;
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break;
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case IRQ_NUBUS_9:
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case IRQ_NUBUS_A:
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case IRQ_NUBUS_B:
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case IRQ_NUBUS_C:
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case IRQ_NUBUS_D:
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case IRQ_NUBUS_E:
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irq -= NUBUS_SOURCE_BASE;
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oss->irq_pending &= ~(1 << irq);
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break;
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}
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}
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/*
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* Check to see if a specific OSS interrupt is pending
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*/
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int oss_irq_pending(int irq)
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{
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switch(irq) {
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case IRQ_SCC:
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case IRQ_SCCA:
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case IRQ_SCCB:
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return oss->irq_pending & OSS_IP_IOPSCC;
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break;
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case IRQ_MAC_ADB:
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return oss->irq_pending & OSS_IP_IOPISM;
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break;
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case IRQ_MAC_SCSI:
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return oss->irq_pending & OSS_IP_SCSI;
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break;
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case IRQ_NUBUS_9:
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case IRQ_NUBUS_A:
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case IRQ_NUBUS_B:
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case IRQ_NUBUS_C:
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case IRQ_NUBUS_D:
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case IRQ_NUBUS_E:
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irq -= NUBUS_SOURCE_BASE;
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return oss->irq_pending & (1 << irq);
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break;
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}
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return 0;
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}
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