/*      $OpenBSD: pcscp.c,v 1.22 2024/05/24 06:02:58 jsg Exp $  */
/*      $NetBSD: pcscp.c,v 1.26 2003/10/19 10:25:42 tsutsui Exp $       */

/*-
 * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center; Izumi Tsutsui.
 *
 * 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.
 */

/*
 * pcscp.c: device dependent code for AMD Am53c974 (PCscsi-PCI)
 * written by Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
 *
 * Technical manual available at
 * http://www.amd.com/files/connectivitysolutions/networking/archivednetworking/19113.pdf
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <machine/bus.h>

#include <scsi/scsi_all.h>
#include <scsi/scsiconf.h>
#include <scsi/scsi_message.h>

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

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

#include <dev/pci/pcscpreg.h>

#define IO_MAP_REG      0x10

struct pcscp_softc {
        struct ncr53c9x_softc sc_ncr53c9x;      /* glue to MI code */

        bus_space_tag_t sc_st;          /* bus space tag */
        bus_space_handle_t sc_sh;       /* bus space handle */
        void *sc_ih;                    /* interrupt cookie */

        bus_dma_tag_t sc_dmat;          /* DMA tag */

        bus_dmamap_t sc_xfermap;        /* DMA map for transfers */

        u_int32_t *sc_mdladdr;          /* MDL array */
        bus_dmamap_t sc_mdldmap;        /* MDL DMA map */

        int     sc_active;              /* DMA state */
        int     sc_datain;              /* DMA Data Direction */
        size_t  sc_dmasize;             /* DMA size */
        char    **sc_dmaaddr;           /* DMA address */
        size_t  *sc_dmalen;             /* DMA length */
};

#define READ_DMAREG(sc, reg) \
        bus_space_read_4((sc)->sc_st, (sc)->sc_sh, (reg))
#define WRITE_DMAREG(sc, reg, var) \
        bus_space_write_4((sc)->sc_st, (sc)->sc_sh, (reg), (var))

#define PCSCP_READ_REG(sc, reg) \
        bus_space_read_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2)
#define PCSCP_WRITE_REG(sc, reg, val) \
        bus_space_write_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2, (val))

int     pcscp_match(struct device *, void *, void *); 
void    pcscp_attach(struct device *, struct device *, void *);  

const struct cfattach pcscp_ca = {
        sizeof(struct pcscp_softc), pcscp_match, pcscp_attach
};

struct cfdriver pcscp_cd = {
        NULL, "pcscp", DV_DULL
};

/*
 * Functions and the switch for the MI code.
 */

u_char  pcscp_read_reg(struct ncr53c9x_softc *, int);
void    pcscp_write_reg(struct ncr53c9x_softc *, int, u_char);
int     pcscp_dma_isintr(struct ncr53c9x_softc *);
void    pcscp_dma_reset(struct ncr53c9x_softc *);
int     pcscp_dma_intr(struct ncr53c9x_softc *);
int     pcscp_dma_setup(struct ncr53c9x_softc *, caddr_t *,
                               size_t *, int, size_t *);
void    pcscp_dma_go(struct ncr53c9x_softc *);
void    pcscp_dma_stop(struct ncr53c9x_softc *);
int     pcscp_dma_isactive(struct ncr53c9x_softc *);

struct ncr53c9x_glue pcscp_glue = {
        pcscp_read_reg,
        pcscp_write_reg,
        pcscp_dma_isintr,
        pcscp_dma_reset,
        pcscp_dma_intr,
        pcscp_dma_setup,
        pcscp_dma_go,
        pcscp_dma_stop,
        pcscp_dma_isactive,
        NULL,                   /* gl_clear_latched_intr */
};

int
pcscp_match(struct device *parent, void *match, void *aux)
{
        struct pci_attach_args *pa = aux;

        if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_AMD)
                return 0;

        switch (PCI_PRODUCT(pa->pa_id)) {
        case PCI_PRODUCT_AMD_PCSCSI_PCI:
                return 1;
        }
        return 0;
}

/*
 * Attach this instance, and then all the sub-devices
 */
void
pcscp_attach(struct device *parent, struct device *self, void *aux)
{
        struct pci_attach_args *pa = aux;
        struct pcscp_softc *esc = (void *)self;
        struct ncr53c9x_softc *sc = &esc->sc_ncr53c9x;
        bus_space_tag_t iot;
        bus_space_handle_t ioh;
        pci_intr_handle_t ih;
        const char *intrstr;
        bus_dma_segment_t seg;
        int error, rseg;

        if (pci_mapreg_map(pa, IO_MAP_REG, PCI_MAPREG_TYPE_IO, 0,
             &iot, &ioh, NULL, NULL, 0)) {
                printf("%s: unable to map registers\n", sc->sc_dev.dv_xname);
                return;
        }

        sc->sc_glue = &pcscp_glue;

        esc->sc_st = iot;
        esc->sc_sh = ioh;
        esc->sc_dmat = pa->pa_dmat;

        /*
         * 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.
         */

        /*
         * XXX should read configuration from EEPROM?
         *
         * MI ncr53c9x driver does not support configuration
         * per each target device, though...
         */
        sc->sc_id = 7;
        sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
        sc->sc_cfg2 = NCRCFG2_SCSI2 | NCRCFG2_FE;
        sc->sc_cfg3 = NCRAMDCFG3_IDM | NCRAMDCFG3_FCLK;
        sc->sc_cfg4 = NCRAMDCFG4_GE12NS | NCRAMDCFG4_RADE;
        sc->sc_rev = NCR_VARIANT_AM53C974;
        sc->sc_features = NCR_F_FASTSCSI;
        sc->sc_cfg3_fscsi = NCRAMDCFG3_FSCSI;
        sc->sc_freq = 40; /* MHz */

        /*
         * 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; 

        /* Really no limit, but since we want to fit into the TCR... */
        sc->sc_maxxfer = 16 * 1024 * 1024;

        /*
         * Create the DMA maps for the data transfers.
         */

#define MDL_SEG_SIZE    0x1000 /* 4kbyte per segment */
#define MDL_SEG_OFFSET  0x0FFF
#define MDL_SIZE        (MAXPHYS / MDL_SEG_SIZE + 1) /* no hardware limit? */

        if (bus_dmamap_create(esc->sc_dmat, MAXPHYS, MDL_SIZE, MDL_SEG_SIZE,
            MDL_SEG_SIZE, BUS_DMA_NOWAIT, &esc->sc_xfermap)) {
                printf("%s: can't create dma maps\n", sc->sc_dev.dv_xname);
                return;
        }

        /*
         * Allocate and map memory for the MDL.
         */

        if ((error = bus_dmamem_alloc(esc->sc_dmat,
            sizeof(u_int32_t) * MDL_SIZE, PAGE_SIZE, 0, &seg, 1, &rseg,
            BUS_DMA_NOWAIT)) != 0) {
                printf("%s: unable to allocate memory for the MDL, "
                    "error = %d\n", sc->sc_dev.dv_xname, error);
                goto fail_0;
        }
        if ((error = bus_dmamem_map(esc->sc_dmat, &seg, rseg,
            sizeof(u_int32_t) * MDL_SIZE , (caddr_t *)&esc->sc_mdladdr,
            BUS_DMA_NOWAIT|BUS_DMA_COHERENT)) != 0) {
                printf("%s: unable to map the MDL memory, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                goto fail_1;
        }
        if ((error = bus_dmamap_create(esc->sc_dmat, 
            sizeof(u_int32_t) * MDL_SIZE, 1, sizeof(u_int32_t) * MDL_SIZE,
            0, BUS_DMA_NOWAIT, &esc->sc_mdldmap)) != 0) {
                printf("%s: unable to map_create for the MDL, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                goto fail_2;
        }
        if ((error = bus_dmamap_load(esc->sc_dmat, esc->sc_mdldmap,
             esc->sc_mdladdr, sizeof(u_int32_t) * MDL_SIZE,
             NULL, BUS_DMA_NOWAIT)) != 0) {
                printf("%s: unable to load for the MDL, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                goto fail_3;
        }

        /* map and establish interrupt */
        if (pci_intr_map(pa, &ih)) {
                printf(": couldn't map interrupt\n");
                goto fail_4;
        }

        intrstr = pci_intr_string(pa->pa_pc, ih);
        esc->sc_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO,
            ncr53c9x_intr, esc, sc->sc_dev.dv_xname);
        if (esc->sc_ih == NULL) {
                printf(": couldn't establish interrupt");
                if (intrstr != NULL)
                        printf(" at %s", intrstr);
                printf("\n");
                goto fail_4;
        }
        if (intrstr != NULL)
                printf(": %s\n", intrstr);

        /* Do the common parts of attachment. */
        printf("%s", sc->sc_dev.dv_xname);

        ncr53c9x_attach(sc);

        /* Turn on target selection using the `dma' method */
        sc->sc_features |= NCR_F_DMASELECT;

        return;

fail_4:
        bus_dmamap_unload(esc->sc_dmat, esc->sc_mdldmap);
fail_3:
        bus_dmamap_destroy(esc->sc_dmat, esc->sc_mdldmap);
fail_2:
        bus_dmamem_unmap(esc->sc_dmat, (caddr_t)esc->sc_mdldmap,
            sizeof(uint32_t) * MDL_SIZE);
fail_1:
        bus_dmamem_free(esc->sc_dmat, &seg, rseg);
fail_0:
        bus_dmamap_destroy(esc->sc_dmat, esc->sc_xfermap);
}

/*
 * Glue functions.
 */

u_char
pcscp_read_reg(struct ncr53c9x_softc *sc, int reg)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;

        return PCSCP_READ_REG(esc, reg);
}

void
pcscp_write_reg(struct ncr53c9x_softc *sc, int reg, u_char v)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;

        PCSCP_WRITE_REG(esc, reg, v);
}

int
pcscp_dma_isintr(struct ncr53c9x_softc *sc)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;

        return (PCSCP_READ_REG(esc, NCR_STAT) & NCRSTAT_INT) != 0;
}

void
pcscp_dma_reset(struct ncr53c9x_softc *sc)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;

        WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE);

        esc->sc_active = 0;
}

int
pcscp_dma_intr(struct ncr53c9x_softc *sc)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;
        int trans, resid, i;
        bus_dmamap_t dmap = esc->sc_xfermap;
        int datain = esc->sc_datain;
        u_int32_t dmastat;
        char *p = NULL;

        dmastat = READ_DMAREG(esc, DMA_STAT);

        if (dmastat & DMASTAT_ERR) {
                /* XXX not tested... */
                WRITE_DMAREG(esc, DMA_CMD,
                    DMACMD_ABORT | (datain ? DMACMD_DIR : 0));

                printf("%s: error: DMA error detected; Aborting.\n",
                    sc->sc_dev.dv_xname);
                bus_dmamap_unload(esc->sc_dmat, dmap);
                return -1;
        }

        if (dmastat & DMASTAT_ABT) {
                /* XXX What should be done? */
                printf("%s: dma_intr: DMA aborted.\n", sc->sc_dev.dv_xname);
                WRITE_DMAREG(esc, DMA_CMD,
                    DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
                esc->sc_active = 0;
                return 0;
        }

#ifdef DIAGNOSTIC
        /* This is an "assertion" :) */
        if (esc->sc_active == 0)
                panic("pcscp dmaintr: DMA wasn't active");
#endif

        /* DMA has stopped */

        esc->sc_active = 0;

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

        resid = 0;
        /*
         * If a transfer onto the SCSI bus gets interrupted by the device
         * (e.g. for a SAVEPOINTER message), the data in the FIFO counts
         * as residual since the ESP counter registers get decremented as
         * bytes are clocked into the FIFO.
         */
        if (!datain &&
            (resid = (PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
                NCR_DMA(("pcscp_dma_intr: empty esp FIFO of %d ", resid));
        }

        if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
                /*
                 * `Terminal count' is off, so read the residue
                 * out of the ESP counter registers.
                 */
                if (datain) {
                        resid = PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
                        while (resid > 1)
                                resid =
                                    PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
                        WRITE_DMAREG(esc, DMA_CMD, DMACMD_BLAST | DMACMD_MDL |
                            (datain ? DMACMD_DIR : 0));

                        for (i = 0; i < 0x8000; i++) /* XXX 0x8000 ? */
                                if (READ_DMAREG(esc, DMA_STAT) & DMASTAT_BCMP)
                                        break;

                        /* See the below comments... */
                        if (resid)
                                p = *esc->sc_dmaaddr;
                }
                
                resid += PCSCP_READ_REG(esc, NCR_TCL) |
                    (PCSCP_READ_REG(esc, NCR_TCM) << 8) |
                    (PCSCP_READ_REG(esc, NCR_TCH) << 16);
        } else {
                while ((dmastat & DMASTAT_DONE) == 0)
                        dmastat = READ_DMAREG(esc, DMA_STAT);
        }

        WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));

        /* sync MDL */
        bus_dmamap_sync(esc->sc_dmat, esc->sc_mdldmap,
            0, sizeof(u_int32_t) * dmap->dm_nsegs, BUS_DMASYNC_POSTWRITE);
        /* sync transfer buffer */
        bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
            datain ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
        bus_dmamap_unload(esc->sc_dmat, dmap);

        trans = esc->sc_dmasize - resid;

        /*
         * From the technical manual notes:
         *
         * `In some odd byte conditions, one residual byte will be left
         *  in the SCSI FIFO, and the FIFO flags will never count to 0.
         *  When this happens, the residual byte should be retrieved
         *  via PIO following completion of the BLAST operation.'
         */
        
        if (p) {
                p += trans;
                *p = PCSCP_READ_REG(esc, NCR_FIFO);
                trans++;
        }

        if (trans < 0) {                        /* transferred < 0 ? */
#if 0
                /*
                 * This situation can happen in perfectly normal operation
                 * if the ESP is reselected while using DMA to select
                 * another target.  As such, don't print the warning.
                 */
                printf("%s: xfer (%d) > req (%d)\n",
                    sc->sc_dev.dv_xname, trans, esc->sc_dmasize);
#endif
                trans = esc->sc_dmasize;
        }

        NCR_DMA(("dmaintr: tcl=%d, tcm=%d, tch=%d; trans=%d, resid=%d\n",
            PCSCP_READ_REG(esc, NCR_TCL),
            PCSCP_READ_REG(esc, NCR_TCM),
            PCSCP_READ_REG(esc, NCR_TCH),
            trans, resid));

        *esc->sc_dmalen -= trans;
        *esc->sc_dmaaddr += trans;

        return 0;
}

int
pcscp_dma_setup(struct ncr53c9x_softc *sc, caddr_t *addr, size_t *len,
    int datain, size_t *dmasize)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;
        bus_dmamap_t dmap = esc->sc_xfermap;
        u_int32_t *mdl;
        int error, nseg, seg;
        bus_addr_t s_offset, s_addr;

        WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));

        esc->sc_dmaaddr = addr;
        esc->sc_dmalen = len;
        esc->sc_dmasize = *dmasize;
        esc->sc_datain = datain;

#ifdef DIAGNOSTIC
        if ((*dmasize / MDL_SEG_SIZE) > MDL_SIZE)
                panic("pcscp: transfer size too large");
#endif

        /*
         * No need to set up DMA in `Transfer Pad' operation.
         * (case of *dmasize == 0)
         */
        if (*dmasize == 0)
                return 0;

        error = bus_dmamap_load(esc->sc_dmat, dmap, *esc->sc_dmaaddr,
            *esc->sc_dmalen, NULL,
            ((sc->sc_nexus->xs->flags & SCSI_NOSLEEP) ?
            BUS_DMA_NOWAIT : BUS_DMA_WAITOK) | BUS_DMA_STREAMING |
            ((sc->sc_nexus->xs->flags & SCSI_DATA_IN) ?
             BUS_DMA_READ : BUS_DMA_WRITE));
        if (error) {
                printf("%s: unable to load dmamap, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                return error;
        }

        /* set transfer length */
        WRITE_DMAREG(esc, DMA_STC, *dmasize); 

        /* set up MDL */
        mdl = esc->sc_mdladdr;
        nseg = dmap->dm_nsegs;

        /* the first segment is possibly not aligned with 4k MDL boundary */
        s_addr = dmap->dm_segs[0].ds_addr;
        s_offset = s_addr & MDL_SEG_OFFSET;
        s_addr -= s_offset;

        /* set the first MDL and offset */
        WRITE_DMAREG(esc, DMA_SPA, s_offset); 
        *mdl++ = htole32(s_addr);

        /* the rest dmamap segments are aligned with 4k boundary */
        for (seg = 1; seg < nseg; seg++)
                *mdl++ = htole32(dmap->dm_segs[seg].ds_addr);

        return 0;
}

void
pcscp_dma_go(struct ncr53c9x_softc *sc)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;
        bus_dmamap_t dmap = esc->sc_xfermap, mdldmap = esc->sc_mdldmap;
        int datain = esc->sc_datain;

        /* No DMA transfer in Transfer Pad operation */
        if (esc->sc_dmasize == 0)
                return;

        /* sync transfer buffer */
        bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
            datain ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);

        /* sync MDL */
        bus_dmamap_sync(esc->sc_dmat, mdldmap,
            0, sizeof(u_int32_t) * dmap->dm_nsegs, BUS_DMASYNC_PREWRITE); 

        /* set Starting MDL Address */
        WRITE_DMAREG(esc, DMA_SMDLA, mdldmap->dm_segs[0].ds_addr);

        /* set DMA command register bits */
        /* XXX DMA Transfer Interrupt Enable bit is broken? */
        WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | DMACMD_MDL |
            /* DMACMD_INTE | */
            (datain ? DMACMD_DIR : 0));

        /* issue DMA start command */
        WRITE_DMAREG(esc, DMA_CMD, DMACMD_START | DMACMD_MDL |
            /* DMACMD_INTE | */
            (datain ? DMACMD_DIR : 0));

        esc->sc_active = 1;
}

void
pcscp_dma_stop(struct ncr53c9x_softc *sc)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;

        /* dma stop */
        /* XXX What should we do here ? */
        WRITE_DMAREG(esc, DMA_CMD,
            DMACMD_ABORT | (esc->sc_datain ? DMACMD_DIR : 0));
        bus_dmamap_unload(esc->sc_dmat, esc->sc_xfermap);

        esc->sc_active = 0;
}

int
pcscp_dma_isactive(struct ncr53c9x_softc *sc)
{
        struct pcscp_softc *esc = (struct pcscp_softc *)sc;

        /* XXX should check esc->sc_active? */
        if ((READ_DMAREG(esc, DMA_CMD) & DMACMD_CMD) != DMACMD_IDLE)
                return 1;
        return 0;
}