/*      $NetBSD: ncr.c,v 1.52 2024/02/17 17:41:43 tsutsui Exp $ */

/*-
 * Copyright (c) 1996 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Adam Glass, David Jones, Gordon W. Ross, and Jens A. Nilsson.
 *
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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.
 */

/*
 * This file contains the machine-dependent parts of the NCR-5380
 * controller. The machine-independent parts are in ncr5380sbc.c.
 *
 * Jens A. Nilsson.
 *
 * Credits:
 * 
 * This code is based on arch/sun3/dev/si*
 * Written by David Jones, Gordon Ross, and Adam Glass.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ncr.c,v 1.52 2024/02/17 17:41:43 tsutsui Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/proc.h>

#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsipi_debug.h>
#include <dev/scsipi/scsiconf.h>

#include <dev/ic/ncr5380reg.h>
#include <dev/ic/ncr5380var.h>

#include <machine/vsbus.h>
#include <machine/sid.h>
#include <machine/scb.h>
#include <machine/clock.h>
#include <machine/ka420.h>

#include "ioconf.h"

#define MIN_DMA_LEN 128

struct si_dma_handle {
        int     dh_flags;
#define SIDH_BUSY       1
#define SIDH_OUT        2
        void *dh_addr;
        int     dh_len;
        struct  proc *dh_proc;
};

struct si_softc {
        struct  ncr5380_softc   ncr_sc;
        struct  evcnt           ncr_intrcnt;
        void *ncr_addr;
        int     ncr_off;
        int     ncr_dmaaddr;
        int     ncr_dmacount;
        int     ncr_dmadir;
        struct  si_dma_handle ncr_dma[SCI_OPENINGS];
        struct  vsbus_dma sc_vd;
        int     onlyscsi;       /* This machine needs no queueing */
};

static int ncr_dmasize;

static  int si_vsbus_match(device_t, cfdata_t, void *);
static  void si_vsbus_attach(device_t, device_t, void *);
static  void si_minphys(struct buf *);

static  void si_dma_alloc(struct ncr5380_softc *);
static  void si_dma_free(struct ncr5380_softc *);
static  void si_dma_setup(struct ncr5380_softc *);
static  void si_dma_start(struct ncr5380_softc *);
static  void si_dma_poll(struct ncr5380_softc *);
static  void si_dma_eop(struct ncr5380_softc *);
static  void si_dma_stop(struct ncr5380_softc *);
static  void si_dma_go(void *);

CFATTACH_DECL_NEW(si_vsbus, sizeof(struct si_softc),
    si_vsbus_match, si_vsbus_attach, NULL, NULL);

static int
si_vsbus_match(device_t parent, cfdata_t cf, void *aux)
{
        struct vsbus_attach_args * const va = aux;
        volatile char *si_csr = (char *) va->va_addr;

        if (vax_boardtype == VAX_BTYP_49 || vax_boardtype == VAX_BTYP_46
            || vax_boardtype == VAX_BTYP_48 || vax_boardtype == VAX_BTYP_53)
                return 0;
        /* This is the way Linux autoprobes the interrupt MK-990321 */
        si_csr[12] = 0;
        si_csr[16] = 0x80;
        si_csr[0] = 0x80;
        si_csr[4] = 5; /* 0xcf */
        DELAY(100000);
        return 1;
}

static void
si_vsbus_attach(device_t parent, device_t self, void *aux)
{
        struct vsbus_attach_args * const va = aux;
        struct si_softc * const sc = device_private(self);
        struct ncr5380_softc * const ncr_sc = &sc->ncr_sc;
        int tweak, target;

        ncr_sc->sc_dev = self;

        scb_vecalloc(va->va_cvec, (void (*)(void *)) ncr5380_intr, sc,
                SCB_ISTACK, &sc->ncr_intrcnt);
        evcnt_attach_dynamic(&sc->ncr_intrcnt, EVCNT_TYPE_INTR, NULL,
                device_xname(self), "intr");

        /*
         * DMA area mapin.
         * On VS3100, split the 128K block between the two devices.
         * On VS2000, don't care for now.
         */
#define DMASIZE (64*1024)
        if (va->va_paddr & 0x100) { /* Secondary SCSI controller */
                sc->ncr_off = DMASIZE;
                sc->onlyscsi = 1;
        }
        sc->ncr_addr = (void *)va->va_dmaaddr;
        ncr_dmasize = uimin(va->va_dmasize, MAXPHYS);

        /*
         * MD function pointers used by the MI code.
         */
        ncr_sc->sc_dma_alloc = si_dma_alloc;
        ncr_sc->sc_dma_free  = si_dma_free;
        ncr_sc->sc_dma_setup = si_dma_setup;
        ncr_sc->sc_dma_start = si_dma_start;
        ncr_sc->sc_dma_poll  = si_dma_poll;
        ncr_sc->sc_dma_eop   = si_dma_eop;
        ncr_sc->sc_dma_stop  = si_dma_stop;

        /* DMA control register offsets */
        sc->ncr_dmaaddr = 32;   /* DMA address in buffer, longword */
        sc->ncr_dmacount = 64;  /* DMA count register */
        sc->ncr_dmadir = 68;    /* Direction of DMA transfer */

        ncr_sc->sc_pio_out = ncr5380_pio_out;
        ncr_sc->sc_pio_in =  ncr5380_pio_in;

        ncr_sc->sc_min_dma_len = MIN_DMA_LEN;

        /*
         * Initialize fields used by the MI code.
         */
/*      ncr_sc->sc_regt =  Unused on VAX */
        ncr_sc->sc_regh = vax_map_physmem(va->va_paddr, 1);

        /* Register offsets */
        ncr_sc->sci_r0 = 0;
        ncr_sc->sci_r1 = 4;
        ncr_sc->sci_r2 = 8;
        ncr_sc->sci_r3 = 12;
        ncr_sc->sci_r4 = 16;
        ncr_sc->sci_r5 = 20;
        ncr_sc->sci_r6 = 24;
        ncr_sc->sci_r7 = 28;

        ncr_sc->sc_rev = NCR_VARIANT_NCR5380;

        ncr_sc->sc_no_disconnect = 0xff;

        /*
         * Get the SCSI chip target address out of NVRAM.
         * This do not apply to the VS2000.
         */
        tweak = clk_tweak + (va->va_paddr & 0x100 ? 3 : 0);
        if (vax_boardtype == VAX_BTYP_410)
                target = 7;
        else
                target = (clk_page[0xbc/2] >> tweak) & 7;

        /*
         * Explicitly enable upto 128KB "Big DMA" on KA420.
         * (It looks KA420 firmware doesn't enable it on network boot)
         */
#define STC_MODE_OFF    (KA420_STC_MODE - KA420_SCS_BASE)
        if (vax_boardtype == VAX_BTYP_420) {
                bus_space_write_1(ncr_sc->sc_regt, ncr_sc->sc_regh,
                    STC_MODE_OFF, 1);
        }

        aprint_normal("\n");
        aprint_normal_dev(self, "NCR5380, SCSI ID %d\n", target);

        ncr_sc->sc_adapter.adapt_minphys = si_minphys;
        ncr_sc->sc_channel.chan_id = target;

        /*
         * Init the vsbus DMA resource queue struct */
        sc->sc_vd.vd_go = si_dma_go;
        sc->sc_vd.vd_arg = sc;

        /*
         * Initialize si board itself.
         */
        ncr5380_attach(ncr_sc);
}

/*
 * Adjust the max transfer size. The DMA buffer is only 16k on VS2000.
 */
static void
si_minphys(struct buf *bp)
{
        if (bp->b_bcount > ncr_dmasize)
                bp->b_bcount = ncr_dmasize;
}

void
si_dma_alloc(struct ncr5380_softc *ncr_sc)
{
        struct si_softc *sc = (struct si_softc *)ncr_sc;
        struct sci_req *sr = ncr_sc->sc_current;
        struct scsipi_xfer *xs = sr->sr_xs;
        struct si_dma_handle *dh;
        int xlen, i;

#ifdef DIAGNOSTIC
        if (sr->sr_dma_hand != NULL)
                panic("si_dma_alloc: already have DMA handle");
#endif

        /* Polled transfers shouldn't allocate a DMA handle. */
        if (sr->sr_flags & SR_IMMED)
                return;

        xlen = ncr_sc->sc_datalen;

        /* Make sure our caller checked sc_min_dma_len. */
        if (xlen < MIN_DMA_LEN)
                panic("si_dma_alloc: len=0x%x", xlen);

        /*
         * Find free PDMA handle.  Guaranteed to find one since we
         * have as many PDMA handles as the driver has processes.
         * (instances?)
         */
         for (i = 0; i < SCI_OPENINGS; i++) {
                if ((sc->ncr_dma[i].dh_flags & SIDH_BUSY) == 0)
                        goto found;
        }
        panic("sbc: no free PDMA handles");
found:
        dh = &sc->ncr_dma[i];
        dh->dh_flags = SIDH_BUSY;
        dh->dh_addr = ncr_sc->sc_dataptr;
        dh->dh_len = xlen;
        if (((vaddr_t)ncr_sc->sc_dataptr & KERNBASE) == 0) {
                if (xs->bp == NULL)
                        panic("si_dma_alloc");
                dh->dh_proc = xs->bp->b_proc;
        }

        /* Remember dest buffer parameters */
        if (xs->xs_control & XS_CTL_DATA_OUT)
                dh->dh_flags |= SIDH_OUT;

        sr->sr_dma_hand = dh;
}

void
si_dma_free(struct ncr5380_softc *ncr_sc)
{
        struct sci_req *sr = ncr_sc->sc_current;
        struct si_dma_handle *dh = sr->sr_dma_hand;

        if (dh->dh_flags & SIDH_BUSY)
                dh->dh_flags = 0;
        else
                printf("si_dma_free: free'ing unused buffer\n");

        sr->sr_dma_hand = NULL;
}

void
si_dma_setup(struct ncr5380_softc *ncr_sc)
{
        /* Do nothing here */
}

void
si_dma_start(struct ncr5380_softc *ncr_sc)
{
        struct si_softc *sc = (struct si_softc *)ncr_sc;

        /* Just put on queue; will call go() from below */
        if (sc->onlyscsi)
                si_dma_go(ncr_sc);
        else
                vsbus_dma_start(&sc->sc_vd);
}

/*
 * go() routine called when another transfer somewhere is finished.
 */
void
si_dma_go(void *arg)
{
        struct ncr5380_softc *ncr_sc = arg;
        struct si_softc *sc = (struct si_softc *)ncr_sc;
        struct sci_req *sr = ncr_sc->sc_current;
        struct si_dma_handle *dh = sr->sr_dma_hand;

        /*
         * Set the VAX-DMA-specific registers, and copy the data if
         * it is directed "outbound".
         */
        if (dh->dh_flags & SIDH_OUT) {
                vsbus_copyfromproc(dh->dh_proc, dh->dh_addr,
                    (char *)sc->ncr_addr + sc->ncr_off, dh->dh_len);
                bus_space_write_1(ncr_sc->sc_regt, ncr_sc->sc_regh,
                    sc->ncr_dmadir, 0);
        } else {
                bus_space_write_1(ncr_sc->sc_regt, ncr_sc->sc_regh,
                    sc->ncr_dmadir, 1);
        }
        bus_space_write_4(ncr_sc->sc_regt, ncr_sc->sc_regh,
            sc->ncr_dmacount, -dh->dh_len);
        bus_space_write_4(ncr_sc->sc_regt, ncr_sc->sc_regh,
            sc->ncr_dmaaddr, sc->ncr_off);
        /*
         * Now from the 5380-internal DMA registers.
         */
        if (dh->dh_flags & SIDH_OUT) {
                NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
                NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
                NCR5380_WRITE(ncr_sc, sci_mode, NCR5380_READ(ncr_sc, sci_mode)
                    | SCI_MODE_DMA | SCI_MODE_DMA_IE);
                NCR5380_WRITE(ncr_sc, sci_dma_send, 0);
        } else {
                NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
                NCR5380_WRITE(ncr_sc, sci_icmd, 0);
                NCR5380_WRITE(ncr_sc, sci_mode, NCR5380_READ(ncr_sc, sci_mode)
                    | SCI_MODE_DMA | SCI_MODE_DMA_IE);
                NCR5380_WRITE(ncr_sc, sci_irecv, 0);
        }
        ncr_sc->sc_state |= NCR_DOINGDMA;
}

/*
 * When?
 */
void
si_dma_poll(struct ncr5380_softc *ncr_sc)
{
        printf("si_dma_poll\n");
}

/*
 * When?
 */
void
si_dma_eop(struct ncr5380_softc *ncr_sc)
{
        printf("si_dma_eop\n");
}

void
si_dma_stop(struct ncr5380_softc *ncr_sc)
{
        struct si_softc *sc = (struct si_softc *)ncr_sc;
        struct sci_req *sr = ncr_sc->sc_current;
        struct si_dma_handle *dh = sr->sr_dma_hand;
        int count, i;

        if (ncr_sc->sc_state & NCR_DOINGDMA) 
                ncr_sc->sc_state &= ~NCR_DOINGDMA;

        /*
         * Sometimes the FIFO buffer isn't drained when the
         * interrupt is posted. Just loop here and hope that
         * it will drain soon.
         */
        for (i = 0; i < 20000; i++) {
                count = bus_space_read_4(ncr_sc->sc_regt,
                    ncr_sc->sc_regh, sc->ncr_dmacount);
                if (count == 0)
                        break;
                DELAY(100);
        }
        if (count == 0) {
                if (((dh->dh_flags & SIDH_OUT) == 0)) {
                        vsbus_copytoproc(dh->dh_proc,
                            (char *)sc->ncr_addr + sc->ncr_off,
                            dh->dh_addr, dh->dh_len);
                }
                ncr_sc->sc_dataptr += dh->dh_len;
                ncr_sc->sc_datalen -= dh->dh_len;
        }

        NCR5380_WRITE(ncr_sc, sci_mode, NCR5380_READ(ncr_sc, sci_mode) &
            ~(SCI_MODE_DMA | SCI_MODE_DMA_IE));
        NCR5380_WRITE(ncr_sc, sci_icmd, 0);
        if (sc->onlyscsi == 0)
                vsbus_dma_intr(); /* Try to start more transfers */
}