[ALSA] emu10k1: Add some descriptive text.

[linux-2.6/verdex.git] / arch / m68k / mac / macints.c

/*
 *      Macintosh interrupts
 *
 * General design:
 * In contrary to the Amiga and Atari platforms, the Mac hardware seems to
 * exclusively use the autovector interrupts (the 'generic level0-level7'
 * interrupts with exception vectors 0x19-0x1f). The following interrupt levels
 * are used:
 *      1       - VIA1
 *                - slot 0: one second interrupt (CA2)
 *                - slot 1: VBlank (CA1)
 *                - slot 2: ADB data ready (SR full)
 *                - slot 3: ADB data  (CB2)
 *                - slot 4: ADB clock (CB1)
 *                - slot 5: timer 2
 *                - slot 6: timer 1
 *                - slot 7: status of IRQ; signals 'any enabled int.'
 *
 *      2       - VIA2 or RBV
 *                - slot 0: SCSI DRQ (CA2)
 *                - slot 1: NUBUS IRQ (CA1) need to read port A to find which
 *                - slot 2: /EXP IRQ (only on IIci)
 *                - slot 3: SCSI IRQ (CB2)
 *                - slot 4: ASC IRQ (CB1)
 *                - slot 5: timer 2 (not on IIci)
 *                - slot 6: timer 1 (not on IIci)
 *                - slot 7: status of IRQ; signals 'any enabled int.'
 *
 *      2       - OSS (IIfx only?)
 *                - slot 0: SCSI interrupt
 *                - slot 1: Sound interrupt
 *
 * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
 *
 *      3       - unused (?)
 *
 *      4       - SCC (slot number determined by reading RR3 on the SSC itself)
 *                - slot 1: SCC channel A
 *                - slot 2: SCC channel B
 *
 *      5       - unused (?)
 *                [serial errors or special conditions seem to raise level 6
 *                interrupts on some models (LC4xx?)]
 *
 *      6       - off switch (?)
 *
 * For OSS Macintoshes (IIfx only at this point):
 *
 *      3       - Nubus interrupt
 *                - slot 0: Slot $9
 *                - slot 1: Slot $A
 *                - slot 2: Slot $B
 *                - slot 3: Slot $C
 *                - slot 4: Slot $D
 *                - slot 5: Slot $E
 *
 *      4       - SCC IOP
 *                - slot 1: SCC channel A
 *                - slot 2: SCC channel B
 *
 *      5       - ISM IOP (ADB?)
 *
 *      6       - unused
 *
 * For PSC Macintoshes (660AV, 840AV):
 *
 *      3       - PSC level 3
 *                - slot 0: MACE
 *
 *      4       - PSC level 4
 *                - slot 1: SCC channel A interrupt
 *                - slot 2: SCC channel B interrupt
 *                - slot 3: MACE DMA
 *
 *      5       - PSC level 5
 *
 *      6       - PSC level 6
 *
 * Finally we have good 'ole level 7, the non-maskable interrupt:
 *
 *      7       - NMI (programmer's switch on the back of some Macs)
 *                Also RAM parity error on models which support it (IIc, IIfx?)
 *
 * The current interrupt logic looks something like this:
 *
 * - We install dispatchers for the autovector interrupts (1-7). These
 *   dispatchers are responsible for querying the hardware (the
 *   VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
 *   this information a machspec interrupt number is generated by placing the
 *   index of the interrupt hardware into the low three bits and the original
 *   autovector interrupt number in the upper 5 bits. The handlers for the
 *   resulting machspec interrupt are then called.
 *
 * - Nubus is a special case because its interrupts are hidden behind two
 *   layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
 *   which translates to IRQ number 17. In this spot we install _another_
 *   dispatcher. This dispatcher finds the interrupting slot number (9-F) and
 *   then forms a new machspec interrupt number as above with the slot number
 *   minus 9 in the low three bits and the pseudo-level 7 in the upper five
 *   bits.  The handlers for this new machspec interrupt number are then
 *   called. This puts Nubus interrupts into the range 56-62.
 *
 * - The Baboon interrupts (used on some PowerBooks) are an even more special
 *   case. They're hidden behind the Nubus slot $C interrupt thus adding a
 *   third layer of indirection. Why oh why did the Apple engineers do that?
 *
 * - We support "fast" and "slow" handlers, just like the Amiga port. The
 *   fast handlers are called first and with all interrupts disabled. They
 *   are expected to execute quickly (hence the name). The slow handlers are
 *   called last with interrupts enabled and the interrupt level restored.
 *   They must therefore be reentrant.
 *
 *   TODO:
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h> /* for intr_count */
#include <linux/delay.h>
#include <linux/seq_file.h>

#include <asm/system.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/bootinfo.h>
#include <asm/machw.h>
#include <asm/macintosh.h>
#include <asm/mac_via.h>
#include <asm/mac_psc.h>
#include <asm/hwtest.h>
#include <asm/errno.h>
#include <asm/macints.h>

#define DEBUG_SPURIOUS
#define SHUTUP_SONIC

/*
 * The mac_irq_list array is an array of linked lists of irq_node_t nodes.
 * Each node contains one handler to be called whenever the interrupt
 * occurs, with fast handlers listed before slow handlers.
 */

irq_node_t *mac_irq_list[NUM_MAC_SOURCES];

/* SCC interrupt mask */

static int scc_mask;

/*
 * VIA/RBV hooks
 */

extern void via_init(void);
extern void via_register_interrupts(void);
extern void via_irq_enable(int);
extern void via_irq_disable(int);
extern void via_irq_clear(int);
extern int  via_irq_pending(int);

/*
 * OSS hooks
 */

extern int oss_present;

extern void oss_init(void);
extern void oss_register_interrupts(void);
extern void oss_irq_enable(int);
extern void oss_irq_disable(int);
extern void oss_irq_clear(int);
extern int  oss_irq_pending(int);

/*
 * PSC hooks
 */

extern int psc_present;

extern void psc_init(void);
extern void psc_register_interrupts(void);
extern void psc_irq_enable(int);
extern void psc_irq_disable(int);
extern void psc_irq_clear(int);
extern int  psc_irq_pending(int);

/*
 * IOP hooks
 */

extern void iop_register_interrupts(void);

/*
 * Baboon hooks
 */

extern int baboon_present;

extern void baboon_init(void);
extern void baboon_register_interrupts(void);
extern void baboon_irq_enable(int);
extern void baboon_irq_disable(int);
extern void baboon_irq_clear(int);
extern int  baboon_irq_pending(int);

/*
 * SCC interrupt routines
 */

static void scc_irq_enable(int);
static void scc_irq_disable(int);

/*
 * console_loglevel determines NMI handler function
 */

extern irqreturn_t mac_bang(int, void *, struct pt_regs *);
irqreturn_t mac_nmi_handler(int, void *, struct pt_regs *);
irqreturn_t mac_debug_handler(int, void *, struct pt_regs *);

/* #define DEBUG_MACINTS */

void mac_init_IRQ(void)
{
        int i;

#ifdef DEBUG_MACINTS
        printk("mac_init_IRQ(): Setting things up...\n");
#endif
        /* Initialize the IRQ handler lists. Initially each list is empty, */

        for (i = 0; i < NUM_MAC_SOURCES; i++) {
                mac_irq_list[i] = NULL;
        }

        scc_mask = 0;

        /* Make sure the SONIC interrupt is cleared or things get ugly */
#ifdef SHUTUP_SONIC
        printk("Killing onboard sonic... ");
        /* This address should hopefully be mapped already */
        if (hwreg_present((void*)(0x50f0a000))) {
                *(long *)(0x50f0a014) = 0x7fffL;
                *(long *)(0x50f0a010) = 0L;
        }
        printk("Done.\n");
#endif /* SHUTUP_SONIC */

        /*
         * Now register the handlers for the master IRQ handlers
         * at levels 1-7. Most of the work is done elsewhere.
         */

        if (oss_present) {
                oss_register_interrupts();
        } else {
                via_register_interrupts();
        }
        if (psc_present) psc_register_interrupts();
        if (baboon_present) baboon_register_interrupts();
        iop_register_interrupts();
        cpu_request_irq(7, mac_nmi_handler, IRQ_FLG_LOCK, "NMI",
                        mac_nmi_handler);
#ifdef DEBUG_MACINTS
        printk("mac_init_IRQ(): Done!\n");
#endif
}

/*
 * Routines to work with irq_node_t's on linked lists lifted from
 * the Amiga code written by Roman Zippel.
 */

static inline void mac_insert_irq(irq_node_t **list, irq_node_t *node)
{
        unsigned long flags;
        irq_node_t *cur;

        if (!node->dev_id)
                printk("%s: Warning: dev_id of %s is zero\n",
                       __FUNCTION__, node->devname);

        local_irq_save(flags);

        cur = *list;

        if (node->flags & IRQ_FLG_FAST) {
                node->flags &= ~IRQ_FLG_SLOW;
                while (cur && cur->flags & IRQ_FLG_FAST) {
                        list = &cur->next;
                        cur = cur->next;
                }
        } else if (node->flags & IRQ_FLG_SLOW) {
                while (cur) {
                        list = &cur->next;
                        cur = cur->next;
                }
        } else {
                while (cur && !(cur->flags & IRQ_FLG_SLOW)) {
                        list = &cur->next;
                        cur = cur->next;
                }
        }

        node->next = cur;
        *list = node;

        local_irq_restore(flags);
}

static inline void mac_delete_irq(irq_node_t **list, void *dev_id)
{
        unsigned long flags;
        irq_node_t *node;

        local_irq_save(flags);

        for (node = *list; node; list = &node->next, node = *list) {
                if (node->dev_id == dev_id) {
                        *list = node->next;
                        /* Mark it as free. */
                        node->handler = NULL;
                        local_irq_restore(flags);
                        return;
                }
        }
        local_irq_restore(flags);
        printk ("%s: tried to remove invalid irq\n", __FUNCTION__);
}

/*
 * Call all the handlers for a given interrupt. Fast handlers are called
 * first followed by slow handlers.
 *
 * This code taken from the original Amiga code written by Roman Zippel.
 */

void mac_do_irq_list(int irq, struct pt_regs *fp)
{
        irq_node_t *node, *slow_nodes;
        unsigned long flags;

        kstat_cpu(0).irqs[irq]++;

#ifdef DEBUG_SPURIOUS
        if (!mac_irq_list[irq] && (console_loglevel > 7)) {
                printk("mac_do_irq_list: spurious interrupt %d!\n", irq);
                return;
        }
#endif

        /* serve first fast and normal handlers */
        for (node = mac_irq_list[irq];
             node && (!(node->flags & IRQ_FLG_SLOW));
             node = node->next)
                node->handler(irq, node->dev_id, fp);
        if (!node) return;
        local_save_flags(flags);
        local_irq_restore((flags & ~0x0700) | (fp->sr & 0x0700));
        /* if slow handlers exists, serve them now */
        slow_nodes = node;
        for (; node; node = node->next) {
                node->handler(irq, node->dev_id, fp);
        }
}

/*
 *  mac_enable_irq - enable an interrupt source
 * mac_disable_irq - disable an interrupt source
 *   mac_clear_irq - clears a pending interrupt
 * mac_pending_irq - Returns the pending status of an IRQ (nonzero = pending)
 *
 * These routines are just dispatchers to the VIA/OSS/PSC routines.
 */

void mac_enable_irq (unsigned int irq)
{
        int irq_src     = IRQ_SRC(irq);

        switch(irq_src) {
                case 1: via_irq_enable(irq);
                        break;
                case 2:
                case 7: if (oss_present) {
                                oss_irq_enable(irq);
                        } else {
                                via_irq_enable(irq);
                        }
                        break;
                case 3:
                case 4:
                case 5:
                case 6: if (psc_present) {
                                psc_irq_enable(irq);
                        } else if (oss_present) {
                                oss_irq_enable(irq);
                        } else if (irq_src == 4) {
                                scc_irq_enable(irq);
                        }
                        break;
                case 8: if (baboon_present) {
                                baboon_irq_enable(irq);
                        }
                        break;
        }
}

void mac_disable_irq (unsigned int irq)
{
        int irq_src     = IRQ_SRC(irq);

        switch(irq_src) {
                case 1: via_irq_disable(irq);
                        break;
                case 2:
                case 7: if (oss_present) {
                                oss_irq_disable(irq);
                        } else {
                                via_irq_disable(irq);
                        }
                        break;
                case 3:
                case 4:
                case 5:
                case 6: if (psc_present) {
                                psc_irq_disable(irq);
                        } else if (oss_present) {
                                oss_irq_disable(irq);
                        } else if (irq_src == 4) {
                                scc_irq_disable(irq);
                        }
                        break;
                case 8: if (baboon_present) {
                                baboon_irq_disable(irq);
                        }
                        break;
        }
}

void mac_clear_irq( unsigned int irq )
{
        switch(IRQ_SRC(irq)) {
                case 1: via_irq_clear(irq);
                        break;
                case 2:
                case 7: if (oss_present) {
                                oss_irq_clear(irq);
                        } else {
                                via_irq_clear(irq);
                        }
                        break;
                case 3:
                case 4:
                case 5:
                case 6: if (psc_present) {
                                psc_irq_clear(irq);
                        } else if (oss_present) {
                                oss_irq_clear(irq);
                        }
                        break;
                case 8: if (baboon_present) {
                                baboon_irq_clear(irq);
                        }
                        break;
        }
}

int mac_irq_pending( unsigned int irq )
{
        switch(IRQ_SRC(irq)) {
                case 1: return via_irq_pending(irq);
                case 2:
                case 7: if (oss_present) {
                                return oss_irq_pending(irq);
                        } else {
                                return via_irq_pending(irq);
                        }
                case 3:
                case 4:
                case 5:
                case 6: if (psc_present) {
                                return psc_irq_pending(irq);
                        } else if (oss_present) {
                                return oss_irq_pending(irq);
                        }
        }
        return 0;
}

/*
 * Add an interrupt service routine to an interrupt source.
 * Returns 0 on success.
 *
 * FIXME: You can register interrupts on nonexistent source (ie PSC4 on a
 *        non-PSC machine). We should return -EINVAL in those cases.
 */

int mac_request_irq(unsigned int irq,
                    irqreturn_t (*handler)(int, void *, struct pt_regs *),
                    unsigned long flags, const char *devname, void *dev_id)
{
        irq_node_t *node;

#ifdef DEBUG_MACINTS
        printk ("%s: irq %d requested for %s\n", __FUNCTION__, irq, devname);
#endif

        if (irq < VIA1_SOURCE_BASE) {
                return cpu_request_irq(irq, handler, flags, devname, dev_id);
        }

        if (irq >= NUM_MAC_SOURCES) {
                printk ("%s: unknown irq %d requested by %s\n",
                        __FUNCTION__, irq, devname);
        }

        /* Get a node and stick it onto the right list */

        if (!(node = new_irq_node())) return -ENOMEM;

        node->handler   = handler;
        node->flags     = flags;
        node->dev_id    = dev_id;
        node->devname   = devname;
        node->next      = NULL;
        mac_insert_irq(&mac_irq_list[irq], node);

        /* Now enable the IRQ source */

        mac_enable_irq(irq);

        return 0;
}

/*
 * Removes an interrupt service routine from an interrupt source.
 */

void mac_free_irq(unsigned int irq, void *dev_id)
{
#ifdef DEBUG_MACINTS
        printk ("%s: irq %d freed by %p\n", __FUNCTION__, irq, dev_id);
#endif

        if (irq < VIA1_SOURCE_BASE) {
                cpu_free_irq(irq, dev_id);
                return;
        }

        if (irq >= NUM_MAC_SOURCES) {
                printk ("%s: unknown irq %d freed\n",
                        __FUNCTION__, irq);
                return;
        }

        mac_delete_irq(&mac_irq_list[irq], dev_id);

        /* If the list for this interrupt is */
        /* empty then disable the source.    */

        if (!mac_irq_list[irq]) {
                mac_disable_irq(irq);
        }
}

/*
 * Generate a pretty listing for /proc/interrupts
 *
 * By the time we're called the autovector interrupt list has already been
 * generated, so we just need to do the machspec interrupts.
 *
 * 990506 (jmt) - rewritten to handle chained machspec interrupt handlers.
 *                Also removed display of num_spurious it is already
 *                displayed for us as autovector irq 0.
 */

int show_mac_interrupts(struct seq_file *p, void *v)
{
        int i;
        irq_node_t *node;
        char *base;

        /* Don't do Nubus interrupts in this loop; we do them separately  */
        /* below so that we can print slot numbers instead of IRQ numbers */

        for (i = VIA1_SOURCE_BASE ; i < NUM_MAC_SOURCES ; ++i) {

                /* Nonexistant interrupt or nothing registered; skip it. */

                if ((node = mac_irq_list[i]) == NULL) continue;
                if (node->flags & IRQ_FLG_STD) continue;

                base = "";
                switch(IRQ_SRC(i)) {
                        case 1: base = "via1";
                                break;
                        case 2: if (oss_present) {
                                        base = "oss";
                                } else {
                                        base = "via2";
                                }
                                break;
                        case 3:
                        case 4:
                        case 5:
                        case 6: if (psc_present) {
                                        base = "psc";
                                } else if (oss_present) {
                                        base = "oss";
                                } else {
                                        if (IRQ_SRC(i) == 4) base = "scc";
                                }
                                break;
                        case 7: base = "nbus";
                                break;
                        case 8: base = "bbn";
                                break;
                }
                seq_printf(p, "%4s %2d: %10u ", base, i, kstat_cpu(0).irqs[i]);

                do {
                        if (node->flags & IRQ_FLG_FAST) {
                                seq_puts(p, "F ");
                        } else if (node->flags & IRQ_FLG_SLOW) {
                                seq_puts(p, "S ");
                        } else {
                                seq_puts(p, "  ");
                        }
                        seq_printf(p, "%s\n", node->devname);
                        if ((node = node->next)) {
                                seq_puts(p, "                    ");
                        }
                } while(node);

        }
        return 0;
}

void mac_default_handler(int irq, void *dev_id, struct pt_regs *regs)
{
#ifdef DEBUG_SPURIOUS
        printk("Unexpected IRQ %d on device %p\n", irq, dev_id);
#endif
}

static int num_debug[8];

irqreturn_t mac_debug_handler(int irq, void *dev_id, struct pt_regs *regs)
{
        if (num_debug[irq] < 10) {
                printk("DEBUG: Unexpected IRQ %d\n", irq);
                num_debug[irq]++;
        }
        return IRQ_HANDLED;
}

static int in_nmi;
static volatile int nmi_hold;

irqreturn_t mac_nmi_handler(int irq, void *dev_id, struct pt_regs *fp)
{
        int i;
        /*
         * generate debug output on NMI switch if 'debug' kernel option given
         * (only works with Penguin!)
         */

        in_nmi++;
        for (i=0; i<100; i++)
                udelay(1000);

        if (in_nmi == 1) {
                nmi_hold = 1;
                printk("... pausing, press NMI to resume ...");
        } else {
                printk(" ok!\n");
                nmi_hold = 0;
        }

        barrier();

        while (nmi_hold == 1)
                udelay(1000);

        if ( console_loglevel >= 8 ) {
#if 0
                show_state();
                printk("PC: %08lx\nSR: %04x  SP: %p\n", fp->pc, fp->sr, fp);
                printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
                       fp->d0, fp->d1, fp->d2, fp->d3);
                printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
                       fp->d4, fp->d5, fp->a0, fp->a1);

                if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
                        printk("Corrupted stack page\n");
                printk("Process %s (pid: %d, stackpage=%08lx)\n",
                        current->comm, current->pid, current->kernel_stack_page);
                if (intr_count == 1)
                        dump_stack((struct frame *)fp);
#else
                /* printk("NMI "); */
#endif
        }
        in_nmi--;
        return IRQ_HANDLED;
}

/*
 * Simple routines for masking and unmasking
 * SCC interrupts in cases where this can't be
 * done in hardware (only the PSC can do that.)
 */

static void scc_irq_enable(int irq) {
        int irq_idx     = IRQ_IDX(irq);

        scc_mask |= (1 << irq_idx);
}

static void scc_irq_disable(int irq) {
        int irq_idx     = IRQ_IDX(irq);

        scc_mask &= ~(1 << irq_idx);
}

/*
 * SCC master interrupt handler. We have to do a bit of magic here
 * to figure out what channel gave us the interrupt; putting this
 * here is cleaner than hacking it into drivers/char/macserial.c.
 */

void mac_scc_dispatch(int irq, void *dev_id, struct pt_regs *regs)
{
        volatile unsigned char *scc = (unsigned char *) mac_bi_data.sccbase + 2;
        unsigned char reg;
        unsigned long flags;

        /* Read RR3 from the chip. Always do this on channel A */
        /* This must be an atomic operation so disable irqs.   */

        local_irq_save(flags);
        *scc = 3;
        reg = *scc;
        local_irq_restore(flags);

        /* Now dispatch. Bits 0-2 are for channel B and */
        /* bits 3-5 are for channel A. We can safely    */
        /* ignore the remaining bits here.              */
        /*                                              */
        /* Note that we're ignoring scc_mask for now.   */
        /* If we actually mask the ints then we tend to */
        /* get hammered by very persistent SCC irqs,    */
        /* and since they're autovector interrupts they */
        /* pretty much kill the system.                 */

        if (reg & 0x38) mac_do_irq_list(IRQ_SCCA, regs);
        if (reg & 0x07) mac_do_irq_list(IRQ_SCCB, regs);
}