/*      $NetBSD: asc_vsbus.c,v 1.45 2018/09/03 16:29:28 riastradh Exp $ */

/*-
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 *
 * 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.
 */

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

__KERNEL_RCSID(0, "$NetBSD: asc_vsbus.c,v 1.45 2018/09/03 16:29:28 riastradh Exp $");

#include "locators.h"
#include "opt_cputype.h"

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

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

#include <dev/ic/ncr53c9xreg.h>
#include <dev/ic/ncr53c9xvar.h>

#include <machine/vmparam.h>
#include <machine/sid.h>
#include <machine/scb.h>
#include <machine/vsbus.h>
#include <machine/clock.h>      /* for SCSI ctlr ID# XXX */

struct asc_vsbus_softc {
        struct ncr53c9x_softc sc_ncr53c9x;      /* Must be first */
        struct evcnt sc_intrcnt;                /* count interrupts */
        bus_space_tag_t sc_bst;                 /* bus space tag */
        bus_space_handle_t sc_bsh;              /* bus space handle */
        bus_space_handle_t sc_dirh;             /* scsi direction handle */
        bus_space_handle_t sc_adrh;             /* scsi address handle */
        bus_space_handle_t sc_ncrh;             /* ncr bus space handle */
        bus_dma_tag_t sc_dmat;                  /* bus DMA tag */
        bus_dmamap_t sc_dmamap;
        uint8_t **sc_dmaaddr;
        size_t *sc_dmalen;
        size_t sc_dmasize;
        unsigned int sc_flags;
#define ASC_FROMMEMORY          0x0001          /* Must be 1 */
#define ASC_DMAACTIVE           0x0002
#define ASC_MAPLOADED           0x0004
        unsigned long sc_xfers;
};

#define ASC_REG_KA46_ADR        0x0000
#define ASC_REG_KA46_DIR        0x000C
#define ASC_REG_KA49_ADR        0x0000
#define ASC_REG_KA49_DIR        0x0004
#define ASC_REG_NCR             0x0080
#define ASC_REG_END             0x00B0

#define ASC_MAXXFERSIZE         65536
#define ASC_FREQUENCY           25000000

static int asc_vsbus_match(device_t, cfdata_t, void *);
static void asc_vsbus_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(asc_vsbus, sizeof(struct asc_vsbus_softc),
    asc_vsbus_match, asc_vsbus_attach, NULL, NULL);

/*
 * Functions and the switch for the MI code
 */
static uint8_t  asc_vsbus_read_reg(struct ncr53c9x_softc *, int);
static void     asc_vsbus_write_reg(struct ncr53c9x_softc *, int, uint8_t);
static int      asc_vsbus_dma_isintr(struct ncr53c9x_softc *);
static void     asc_vsbus_dma_reset(struct ncr53c9x_softc *);
static int      asc_vsbus_dma_intr(struct ncr53c9x_softc *);
static int      asc_vsbus_dma_setup(struct ncr53c9x_softc *, uint8_t **,
                    size_t *, int, size_t *);
static void     asc_vsbus_dma_go(struct ncr53c9x_softc *);
static void     asc_vsbus_dma_stop(struct ncr53c9x_softc *);
static int      asc_vsbus_dma_isactive(struct ncr53c9x_softc *);

static const struct ncr53c9x_glue asc_vsbus_glue = {
        .gl_read_reg    = asc_vsbus_read_reg,
        .gl_write_reg   = asc_vsbus_write_reg,
        .gl_dma_isintr  = asc_vsbus_dma_isintr,
        .gl_dma_reset   = asc_vsbus_dma_reset,
        .gl_dma_intr    = asc_vsbus_dma_intr,
        .gl_dma_setup   = asc_vsbus_dma_setup,
        .gl_dma_go      = asc_vsbus_dma_go,
        .gl_dma_stop    = asc_vsbus_dma_stop,
        .gl_dma_isactive = asc_vsbus_dma_isactive,
};

static uint8_t asc_attached;            /* can't have more than one asc */

static int
asc_vsbus_match(device_t parent, cfdata_t cf, void *aux)
{
        struct vsbus_attach_args * const va = aux;
        volatile uint8_t *ncr_regs;
        int dummy;

        if (asc_attached)
                return 0;

        if (vax_boardtype == VAX_BTYP_46 || vax_boardtype == VAX_BTYP_48) {
                if (cf->cf_loc[VSBUSCF_CSR] != 0x200c0080)
                        return 0;
        } else if (vax_boardtype == VAX_BTYP_49 ||
            vax_boardtype == VAX_BTYP_53) {
                if (cf->cf_loc[VSBUSCF_CSR] != 0x26000080)
                        return 0;
        } else {
                return 0;
        }

        ncr_regs = (volatile uint8_t *) va->va_addr;

        /*  *** need to generate an interrupt here
         * From trial and error, I've determined that an INT is generated
         * only when the following sequence of events occurs:
         *   1) The interrupt status register (0x05) must be read.
         *   2) SCSI bus reset interrupt must be enabled
         *   3) SCSI bus reset command must be sent
         *   4) NOP command must be sent
         */

        dummy = ncr_regs[NCR_INTR << 2] & 0xFF;
        ncr_regs[NCR_CFG1 << 2] = 0x06; /* we're ID 6, turn on INT for SCSI reset */
        ncr_regs[NCR_CMD << 2] = NCRCMD_RSTSCSI; /* send the reset */
        ncr_regs[NCR_CMD << 2] = NCRCMD_NOP; /* send a NOP */
        DELAY(10000);

        dummy = ncr_regs[NCR_INTR << 2] & 0xFF;
        return (dummy & NCRINTR_SBR) != 0;
}


/*
 * Attach this instance, and then all the sub-devices
 */
static void
asc_vsbus_attach(device_t parent, device_t self, void *aux)
{
        struct vsbus_attach_args * const va = aux;
        struct asc_vsbus_softc * const asc = device_private(self);
        struct ncr53c9x_softc * const sc = &asc->sc_ncr53c9x;
        int error;

        asc_attached = 1;
        /*
         * Set up glue for MI code early; we use some of it here.
         */
        sc->sc_dev = self;
        sc->sc_glue = &asc_vsbus_glue;

        asc->sc_bst = va->va_memt;
        asc->sc_dmat = va->va_dmat;

        error = bus_space_map(asc->sc_bst, va->va_paddr - ASC_REG_NCR,
            ASC_REG_END, 0, &asc->sc_bsh);
        if (error) {
                aprint_error(": failed to map registers: error=%d\n", error);
                return;
        }
        error = bus_space_subregion(asc->sc_bst, asc->sc_bsh, ASC_REG_NCR,
            ASC_REG_END - ASC_REG_NCR, &asc->sc_ncrh);
        if (error) {
                aprint_error(": failed to map ncr registers: error=%d\n",
                    error);
                return;
        }
        if (vax_boardtype == VAX_BTYP_46 || vax_boardtype == VAX_BTYP_48) {
                error = bus_space_subregion(asc->sc_bst, asc->sc_bsh,
                    ASC_REG_KA46_ADR, sizeof(uint32_t), &asc->sc_adrh);
                if (error) {
                        aprint_error(": failed to map adr register: error=%d\n",
                             error);
                        return;
                }
                error = bus_space_subregion(asc->sc_bst, asc->sc_bsh,
                    ASC_REG_KA46_DIR, sizeof(uint32_t), &asc->sc_dirh);
                if (error) {
                        aprint_error(": failed to map dir register: error=%d\n",
                             error);
                        return;
                }
        } else {
                /* This is a gross and disgusting kludge but it'll
                 * save a bunch of ugly code.  Unlike the VS4000/60,
                 * the SCSI Address and direction registers are not
                 * near the SCSI NCR registers and are inside the 
                 * block of general VAXstation registers.  So we grab
                 * them from there and knowing the internals of the 
                 * bus_space implementation, we cast to bus_space_handles.
                 */
                struct vsbus_softc *vsc = device_private(parent);
                asc->sc_adrh =
                    (bus_space_handle_t)(vsc->sc_vsregs + ASC_REG_KA49_ADR);
                asc->sc_dirh =
                    (bus_space_handle_t)(vsc->sc_vsregs + ASC_REG_KA49_DIR);
#if 0
                printf("\n%s: adrh=0x%08lx dirh=0x%08lx", device_xname(self),
                    asc->sc_adrh, asc->sc_dirh);
                ncr53c9x_debug = NCR_SHOWDMA | NCR_SHOWINTS | NCR_SHOWCMDS |
                    NCR_SHOWPHASE | NCR_SHOWSTART | NCR_SHOWMSGS;
#endif
        }
        error = bus_dmamap_create(asc->sc_dmat, ASC_MAXXFERSIZE, 1, 
            ASC_MAXXFERSIZE, 0, BUS_DMA_NOWAIT, &asc->sc_dmamap);

#if defined(VAX46) || defined(VAX48) || defined(VAX49) || defined(VAXANY)
        if(vax_boardtype != VAX_BTYP_53)
                /* SCSI ID is store in the clock NVRAM at magic address 0xbc */
                sc->sc_id = (clk_page[0xbc / 2] >> clk_tweak) & 7;
        else
#endif
                sc->sc_id = 6; /* XXX need to get this from VMB */
        sc->sc_freq = ASC_FREQUENCY;

        /* gimme MHz */
        sc->sc_freq /= 1000000;

        scb_vecalloc(va->va_cvec, (void (*)(void *))ncr53c9x_intr,
            &asc->sc_ncr53c9x, SCB_ISTACK, &asc->sc_intrcnt);
        evcnt_attach_dynamic(&asc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
            device_xname(self), "intr");

        /*
         * XXX More of this should be in ncr53c9x_attach(), but
         * XXX should we really poke around the chip that much in
         * XXX the MI code?  Think about this more...
         */

        /*
         * Set up static configuration info.
         */
        sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
        sc->sc_cfg2 = NCRCFG2_SCSI2;
        sc->sc_cfg3 = 0;
        sc->sc_rev = NCR_VARIANT_NCR53C94;

        /*
         * XXX minsync and maxxfer _should_ be set up in MI code,
         * XXX but it appears to have some dependency on what sort
         * XXX of DMA we're hooked up to, etc.
         */

        /*
         * This is the value used to start sync negotiations
         * Note that the NCR register "SYNCTP" is programmed
         * in "clocks per byte", and has a minimum value of 4.
         * The SCSI period used in negotiation is one-fourth
         * of the time (in nanoseconds) needed to transfer one byte.
         * Since the chip's clock is given in MHz, we have the following
         * formula: 4 * period = (1000 / freq) * 4
         */
        sc->sc_minsync = (1000 / sc->sc_freq);
        sc->sc_maxxfer = 64 * 1024;

        aprint_normal("\n%s", device_xname(self)); /* Pretty print */

        /* Do the common parts of attachment. */
        sc->sc_adapter.adapt_minphys = minphys;
        sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
        ncr53c9x_attach(sc);
}

/*
 * Glue functions.
 */

static uint8_t
asc_vsbus_read_reg(struct ncr53c9x_softc *sc, int reg)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        return bus_space_read_1(asc->sc_bst, asc->sc_ncrh,
            reg * sizeof(uint32_t));
}

static void
asc_vsbus_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t val)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        bus_space_write_1(asc->sc_bst, asc->sc_ncrh,
            reg * sizeof(uint32_t), val);
}

static int
asc_vsbus_dma_isintr(struct ncr53c9x_softc *sc)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        return bus_space_read_1(asc->sc_bst, asc->sc_ncrh,
            NCR_STAT * sizeof(uint32_t)) & NCRSTAT_INT;
}

static void
asc_vsbus_dma_reset(struct ncr53c9x_softc *sc)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        if (asc->sc_flags & ASC_MAPLOADED)
                bus_dmamap_unload(asc->sc_dmat, asc->sc_dmamap);
        asc->sc_flags &= ~(ASC_DMAACTIVE|ASC_MAPLOADED);
}

static int
asc_vsbus_dma_intr(struct ncr53c9x_softc *sc)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;
        u_int tcl, tcm;
        int trans, resid;
        
        if ((asc->sc_flags & ASC_DMAACTIVE) == 0)
                panic("%s: DMA wasn't active", __func__);

        asc->sc_flags &= ~ASC_DMAACTIVE;

        if (asc->sc_dmasize == 0) {
                /* A "Transfer Pad" operation completed */
                tcl = NCR_READ_REG(sc, NCR_TCL);
                tcm = NCR_READ_REG(sc, NCR_TCM);
                NCR_DMA(("asc_vsbus_intr: discarded %d bytes (tcl=%d, tcm=%d)\n",
                    tcl | (tcm << 8), tcl, tcm));
                return 0;
        }

        resid = 0;
        if ((resid = (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
                NCR_DMA(("asc_vsbus_intr: empty FIFO of %d ", resid));
                DELAY(1);
        }
        if (asc->sc_flags & ASC_MAPLOADED) {
                bus_dmamap_sync(asc->sc_dmat, asc->sc_dmamap,
                                0, asc->sc_dmasize,
                                asc->sc_flags & ASC_FROMMEMORY
                                        ? BUS_DMASYNC_POSTWRITE
                                        : BUS_DMASYNC_POSTREAD);
                bus_dmamap_unload(asc->sc_dmat, asc->sc_dmamap);
        }
        asc->sc_flags &= ~ASC_MAPLOADED;

        resid += (tcl = NCR_READ_REG(sc, NCR_TCL));
        resid += (tcm = NCR_READ_REG(sc, NCR_TCM)) << 8;

        trans = asc->sc_dmasize - resid;
        if (trans < 0) {                        /* transferred < 0 ? */
                printf("asc_vsbus_intr: xfer (%d) > req (%lu)\n",
                    trans, (u_long) asc->sc_dmasize);
                trans = asc->sc_dmasize;
        }
        NCR_DMA(("asc_vsbus_intr: tcl=%d, tcm=%d; trans=%d, resid=%d\n",
            tcl, tcm, trans, resid));

        *asc->sc_dmalen -= trans;
        *asc->sc_dmaaddr += trans;
        
        asc->sc_xfers++;
        return 0;
}

static int
asc_vsbus_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
                    int datain, size_t *dmasize)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        asc->sc_dmaaddr = addr;
        asc->sc_dmalen = len;
        if (datain) {
                asc->sc_flags &= ~ASC_FROMMEMORY;
        } else {
                asc->sc_flags |= ASC_FROMMEMORY;
        }
        if ((vaddr_t)*asc->sc_dmaaddr < VM_MIN_KERNEL_ADDRESS)
                panic("%s: DMA address (%p) outside of kernel",
                    __func__, *asc->sc_dmaaddr);

        NCR_DMA(("%s: start %d@%p,%d\n", device_xname(sc->sc_dev),
            (int)*asc->sc_dmalen, *asc->sc_dmaaddr,
            (asc->sc_flags & ASC_FROMMEMORY)));
        *dmasize = asc->sc_dmasize = uimin(*dmasize, ASC_MAXXFERSIZE);

        if (asc->sc_dmasize) {
                if (bus_dmamap_load(asc->sc_dmat, asc->sc_dmamap,
                                *asc->sc_dmaaddr, asc->sc_dmasize,
                                NULL /* kernel address */,   
                                BUS_DMA_NOWAIT|VAX_BUS_DMA_SPILLPAGE))
                        panic("%s: cannot load DMA map",
                            device_xname(sc->sc_dev));
                bus_dmamap_sync(asc->sc_dmat, asc->sc_dmamap,
                                0, asc->sc_dmasize,
                                asc->sc_flags & ASC_FROMMEMORY
                                        ? BUS_DMASYNC_PREWRITE
                                        : BUS_DMASYNC_PREREAD);
                bus_space_write_4(asc->sc_bst, asc->sc_adrh, 0,
                                  asc->sc_dmamap->dm_segs[0].ds_addr);
                bus_space_write_4(asc->sc_bst, asc->sc_dirh, 0,
                                  asc->sc_flags & ASC_FROMMEMORY);
                NCR_DMA(("%s: dma-load %lu@0x%08lx\n",
                    device_xname(sc->sc_dev),
                    asc->sc_dmamap->dm_segs[0].ds_len,
                    asc->sc_dmamap->dm_segs[0].ds_addr));
                asc->sc_flags |= ASC_MAPLOADED;
        }

        return 0;
}

static void
asc_vsbus_dma_go(struct ncr53c9x_softc *sc)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        asc->sc_flags |= ASC_DMAACTIVE;
}

static void
asc_vsbus_dma_stop(struct ncr53c9x_softc *sc)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        if (asc->sc_flags & ASC_MAPLOADED) {
                bus_dmamap_sync(asc->sc_dmat, asc->sc_dmamap,
                                0, asc->sc_dmasize,
                                asc->sc_flags & ASC_FROMMEMORY
                                        ? BUS_DMASYNC_POSTWRITE
                                        : BUS_DMASYNC_POSTREAD);
                bus_dmamap_unload(asc->sc_dmat, asc->sc_dmamap);
        }

        asc->sc_flags &= ~(ASC_DMAACTIVE|ASC_MAPLOADED);
}

static int
asc_vsbus_dma_isactive(struct ncr53c9x_softc *sc)
{
        struct asc_vsbus_softc * const asc = (struct asc_vsbus_softc *)sc;

        return (asc->sc_flags & ASC_DMAACTIVE) != 0;
}