/*      $NetBSD: mba.c,v 1.42 2021/08/07 16:19:07 thorpej Exp $ */
/*
 * Copyright (c) 1994, 1996 Ludd, University of Lule}, Sweden.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Simple massbus drive routine.
 * TODO:
 *  Autoconfig new devices 'on the fly'.
 *  More intelligent way to handle different interrupts.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mba.c,v 1.42 2021/08/07 16:19:07 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/queue.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/proc.h>

#include <machine/scb.h>
#include <machine/nexus.h>
#include <machine/pte.h>
#include <machine/sid.h>
#include <machine/sid.h>

#include <vax/mba/mbareg.h>
#include <vax/mba/mbavar.h>

#include "locators.h"

const struct mbaunit mbaunit[] = {
        {MBADT_RP04,    "rp04", MB_RP},
        {MBADT_RP05,    "rp05", MB_RP},
        {MBADT_RP06,    "rp06", MB_RP},
        {MBADT_RP07,    "rp07", MB_RP},
        {MBADT_RM02,    "rm02", MB_RP},
        {MBADT_RM03,    "rm03", MB_RP},
        {MBADT_RM05,    "rm05", MB_RP},
        {MBADT_RM80,    "rm80", MB_RP},
        {0,             0,      0}
};

void    mbaqueue(struct mba_device *);

static int      mbamatch(device_t, cfdata_t, void *);
static void     mbaattach(device_t, device_t, void *);
static void     mbaintr(void *);
static int      mbaprint(void *, const char *);
static void     mbastart(struct mba_softc *);

CFATTACH_DECL_NEW(mba_cmi, sizeof(struct mba_softc),
    mbamatch, mbaattach, NULL, NULL);

CFATTACH_DECL_NEW(mba_sbi, sizeof(struct mba_softc),
    mbamatch, mbaattach, NULL, NULL);

#define MBA_WCSR(reg, val) \
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, (reg), (val))
#define MBA_RCSR(reg) \
        bus_space_read_4(sc->sc_iot, sc->sc_ioh, (reg))

/*
 * Look if this is a massbuss adapter.
 */
int
mbamatch(device_t parent, cfdata_t cf, void *aux)
{
        struct sbi_attach_args * const sa = aux;

        if (vax_cputype == VAX_750) {
                if (cf->cf_loc[CMICF_TR] != CMICF_TR_DEFAULT &&
                    cf->cf_loc[CMICF_TR] != sa->sa_nexnum)
                        return 0;
        } else {
                if (cf->cf_loc[SBICF_TR] != SBICF_TR_DEFAULT &&
                    cf->cf_loc[SBICF_TR] != sa->sa_nexnum)
                        return 0;
        }

        if (sa->sa_type == NEX_MBA)
                return 1;

        return 0;
}

/*
 * Attach the found massbuss adapter. Setup its interrupt vectors,
 * reset it and go searching for drives on it.
 */
void
mbaattach(device_t parent, device_t self, void *aux)
{
        struct mba_softc * const sc = device_private(self);
        struct sbi_attach_args * const sa = aux;
        struct mba_attach_args ma;
        int     i, j;

        aprint_normal("\n");

        sc->sc_dev = self;
        sc->sc_iot = sa->sa_iot;
        sc->sc_ioh = sa->sa_ioh;
        /*
         * Set up interrupt vectors for this MBA.
         */
        for (i = 0x14; i < 0x18; i++)
                scb_vecalloc(vecnum(0, i, sa->sa_nexnum),
                    mbaintr, sc, SCB_ISTACK, &sc->sc_intrcnt);
        evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
                device_xname(self), "intr");

        STAILQ_INIT(&sc->sc_xfers);
        MBA_WCSR(MBA_CR, MBACR_INIT);   /* Reset adapter */
        MBA_WCSR(MBA_CR, MBACR_IE);     /* Enable interrupts */

        for (i = 0; i < MAXMBADEV; i++) {
                sc->sc_state = SC_AUTOCONF;
                if ((MBA_RCSR(MUREG(i, MU_DS)) & MBADS_DPR) == 0) 
                        continue;
                /* We have a drive, ok. */
                ma.ma_unit = i;
                ma.ma_type = MBA_RCSR(MUREG(i, MU_DT)) & 0xf1ff;
                for (j = 0; mbaunit[j].nr; j++)
                        if (mbaunit[j].nr == ma.ma_type)
                                break;
                ma.ma_devtyp = mbaunit[j].devtyp;
                ma.ma_name = mbaunit[j].name;
                ma.ma_iot = sc->sc_iot;
                ma.ma_ioh = sc->sc_ioh + MUREG(i, 0);
                config_found(sc->sc_dev, &ma, mbaprint, CFARGS_NONE);
        }
}

/*
 * We got an interrupt. Check type of interrupt and call the specific
 * device interrupt handling routine.
 */
void
mbaintr(void *mba)
{
        struct mba_softc * const sc = mba;
        struct mba_device *md;
        struct buf *bp;
        int itype, attn, anr;

        itype = MBA_RCSR(MBA_SR);
        MBA_WCSR(MBA_SR, itype);

        attn = MBA_RCSR(MUREG(0, MU_AS)) & 0xff;
        MBA_WCSR(MUREG(0, MU_AS), attn);

        if (sc->sc_state == SC_AUTOCONF)
                return; /* During autoconfig */

        md = STAILQ_FIRST(&sc->sc_xfers);
        bp = bufq_peek(md->md_q);
        /*
         * A data-transfer interrupt. Current operation is finished,
         * call that device's finish routine to see what to do next.
         */
        if (sc->sc_state == SC_ACTIVE) {
                sc->sc_state = SC_IDLE;
                switch ((*md->md_finish)(md, itype, &attn)) {

                case XFER_FINISH:
                        /*
                         * Transfer is finished. Take buffer of drive
                         * queue, and take drive of adapter queue.
                         * If more to transfer, start the adapter again
                         * by calling mbastart().
                         */
                        (void)bufq_get(md->md_q);
                        STAILQ_REMOVE_HEAD(&sc->sc_xfers, md_link);
                        if (bufq_peek(md->md_q) != NULL) {
                                STAILQ_INSERT_TAIL(&sc->sc_xfers, md, md_link);
                        }
        
                        bp->b_resid = 0;
                        biodone(bp);
                        if (!STAILQ_EMPTY(&sc->sc_xfers))
                                mbastart(sc);
                        break;

                case XFER_RESTART:
                        /*
                         * Something went wrong with the transfer. Try again.
                         */
                        mbastart(sc);
                        break;
                }
        }

        while (attn) {
                anr = ffs(attn) - 1;
                attn &= ~(1 << anr);
                if (sc->sc_md[anr]->md_attn == 0)
                        panic("Should check for new MBA device %d", anr);
                (*sc->sc_md[anr]->md_attn)(sc->sc_md[anr]);
        }
}

int
mbaprint(void *aux, const char *mbaname)
{
        struct mba_attach_args * const ma = aux;

        if (mbaname) {
                if (ma->ma_name)
                        aprint_normal("%s", ma->ma_name);
                else
                        aprint_normal("device type %o", ma->ma_type);
                aprint_normal(" at %s", mbaname);
        }
        aprint_normal(" drive %d", ma->ma_unit);
        return (ma->ma_name ? UNCONF : UNSUPP);
}

/*
 * A device calls mbaqueue() when it wants to get on the adapter queue.
 * Called at splbio(). If the adapter is inactive, start it. 
 */
void
mbaqueue(struct mba_device *md)
{
        struct mba_softc * const sc = md->md_mba;
        bool was_empty = STAILQ_EMPTY(&sc->sc_xfers);

        STAILQ_INSERT_TAIL(&sc->sc_xfers, md, md_link);

        if (was_empty)
                mbastart(sc);
}

/*
 * Start activity on (idling) adapter. Calls disk_reallymapin() to setup
 * for DMA transfer, then the unit-specific start routine.
 */
void
mbastart(struct mba_softc *sc)
{
        struct mba_device * const md = STAILQ_FIRST(&sc->sc_xfers);
        struct buf *bp = bufq_peek(md->md_q);

        disk_reallymapin(bp, (void *)(sc->sc_ioh + MAPREG(0)), 0, PG_V);

        sc->sc_state = SC_ACTIVE;
        MBA_WCSR(MBA_VAR, ((u_int)bp->b_data & VAX_PGOFSET));
        MBA_WCSR(MBA_BC, (~bp->b_bcount) + 1);
        (*md->md_start)(md);            /* machine-dependent start */
}