/* $NetBSD: pci_kn20aa.c,v 1.59 2021/07/04 22:42:36 thorpej Exp $ */

/*
 * Copyright (c) 1995, 1996 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#include <sys/cdefs.h>                  /* RCS ID & Copyright macro defns */

__KERNEL_RCSID(0, "$NetBSD: pci_kn20aa.c,v 1.59 2021/07/04 22:42:36 thorpej Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/syslog.h>

#include <machine/autoconf.h>
#include <machine/rpb.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <alpha/pci/ciareg.h>
#include <alpha/pci/ciavar.h>

#include "sio.h"
#if NSIO > 0 || NPCEB > 0
#include <alpha/pci/siovar.h>
#endif

static int      dec_kn20aa_intr_map(const struct pci_attach_args *,
                    pci_intr_handle_t *);

#define KN20AA_PCEB_IRQ 31
#define KN20AA_MAX_IRQ  32
#define PCI_STRAY_MAX   5

static void     kn20aa_enable_intr(pci_chipset_tag_t pc, int irq);
static void     kn20aa_disable_intr(pci_chipset_tag_t pc, int irq);

static void
pci_kn20aa_pickintr(void *core, bus_space_tag_t iot, bus_space_tag_t memt,
    pci_chipset_tag_t pc)
{
        int i;

        pc->pc_intr_v = core;
        pc->pc_intr_map = dec_kn20aa_intr_map;
        pc->pc_intr_string = alpha_pci_generic_intr_string;
        pc->pc_intr_evcnt = alpha_pci_generic_intr_evcnt;
        pc->pc_intr_establish = alpha_pci_generic_intr_establish;
        pc->pc_intr_disestablish = alpha_pci_generic_intr_disestablish;

        /* Not supported on KN20AA. */
        pc->pc_pciide_compat_intr_establish = NULL;

        pc->pc_intr_desc = "kn20aa";
        pc->pc_vecbase = 0x900;
        pc->pc_nirq = KN20AA_MAX_IRQ;

        pc->pc_intr_enable = kn20aa_enable_intr;
        pc->pc_intr_disable = kn20aa_disable_intr;

        for (i = 0; i < KN20AA_MAX_IRQ; i++) {
                kn20aa_disable_intr(pc, i);
        }

        alpha_pci_intr_alloc(pc, PCI_STRAY_MAX);

#if NSIO > 0 || NPCEB > 0
        sio_intr_setup(pc, iot);
        kn20aa_enable_intr(pc, KN20AA_PCEB_IRQ);
#endif
}
ALPHA_PCI_INTR_INIT(ST_DEC_KN20AA, pci_kn20aa_pickintr)

static int
dec_kn20aa_intr_map(const struct pci_attach_args *pa, pci_intr_handle_t *ihp)
{
        pcitag_t bustag = pa->pa_intrtag;
        int buspin = pa->pa_intrpin;
        pci_chipset_tag_t pc = pa->pa_pc;
        int device;
        int kn20aa_irq;

        if (buspin == 0) {
                /* No IRQ used. */
                return 1;
        }
        if (buspin < 0 || buspin > 4) {
                printf("dec_kn20aa_intr_map: bad interrupt pin %d\n", buspin);
                return 1;
        }

        /*
         * Slot->interrupt translation.  Appears to work, though it
         * may not hold up forever.
         *
         * The DEC engineers who did this hardware obviously engaged
         * in random drug testing.
         */
        pci_decompose_tag(pc, bustag, NULL, &device, NULL);
        switch (device) {
        case 11:
        case 12:
                kn20aa_irq = ((device - 11) + 0) * 4;
                break;

        case 7:
                kn20aa_irq = 8;
                break;

        case 9:
                kn20aa_irq = 12;
                break;

        case 6:                                 /* 21040 on AlphaStation 500 */
                kn20aa_irq = 13;
                break;

        case 8:
                kn20aa_irq = 16;
                break;

        default:
                printf("dec_kn20aa_intr_map: weird device number %d\n",
                    device);
                return 1;
        }

        kn20aa_irq += buspin - 1;
        if (kn20aa_irq > KN20AA_MAX_IRQ)
                panic("dec_kn20aa_intr_map: kn20aa_irq too large (%d)",
                    kn20aa_irq);

        alpha_pci_intr_handle_init(ihp, kn20aa_irq, 0);
        return (0);
}

static void
kn20aa_enable_intr(pci_chipset_tag_t pc __unused, int irq)
{

        /*
         * From disassembling small bits of the OSF/1 kernel:
         * the following appears to enable a given interrupt request.
         * "blech."  I'd give valuable body parts for better docs or
         * for a good decompiler.
         */
        alpha_mb();
        REGVAL(0x8780000000L + 0x40L) |= (1 << irq);    /* XXX */
        alpha_mb();
}

static void
kn20aa_disable_intr(pci_chipset_tag_t pc __unused, int irq)
{

        alpha_mb();
        REGVAL(0x8780000000L + 0x40L) &= ~(1 << irq);   /* XXX */
        alpha_mb();
}