/*      $NetBSD: oak.c,v 1.22 2025/05/19 06:16:24 andvar Exp $  */

/*
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Mark Brinicombe of Causality Limited.
 *
 * 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.
 */

/*
 * Oak Solutions SCSI 1 driver using the generic NCR5380 driver.
 *
 * From <URL:http://foldoc.doc.ic.ac.uk/acorn/doc/scsi>:
 * --------8<--------
 * From: Hugo Fiennes
 * [...]
 * The oak scsi plays some other tricks to get max around 2.2Mb/sec:
 * it is a 16- bit interface (using their own hardware and an 8-bit
 * scsi controller to 'double-up' the data). What it does is: every
 * 128 bytes it uses a polling loop (see above) to check data is
 * present and the drive has reported no errors, etc.  Inside each 128
 * byte block it just reads data as fast as it can: on a normal card
 * this would result in disaster if the drive wasn't fast enough to
 * feed the machine: on the oak card however, the hardware will not
 * assert IOGT (IO grant), so hanging the machine in a wait state
 * until data is ready. This can have problems: if the drive is to
 * slow (unlikely) the machine will completely stiff as the ARM3 can't
 * be kept in such a state for more than 10(?) us.
 * -------->8--------
 *
 * So far, my attempts at doing this have failed, though.
 *
 * This card has to be polled: it doesn't have anything connected to
 * PIRQ*.  This seems to be a common failing of Archimedes disc
 * controllers.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: oak.c,v 1.22 2025/05/19 06:16:24 andvar Exp $");

#include <sys/param.h>

#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/buf.h>
#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsiconf.h>

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

#include <machine/bootconfig.h>

#include <dev/podulebus/podulebus.h>
#include <dev/podulebus/podules.h>
#include <dev/podulebus/powerromreg.h>

#include <dev/podulebus/oakreg.h>

int  oak_match(device_t, cfdata_t, void *);
void oak_attach(device_t, device_t, void *);

#if 0
static int oak_pdma_in(struct ncr5380_softc *, int, int, uint8_t *);
static int oak_pdma_out(struct ncr5380_softc *, int, int, uint8_t *);
#endif

/*
 * Oak SCSI 1 softc structure.
 *
 * Contains the generic ncr5380 device node, podule information and
 * global information required by the driver.
 */

struct oak_softc {
        struct ncr5380_softc    sc_ncr5380;
        bus_space_tag_t         sc_pdmat;
        bus_space_handle_t      sc_pdmah;
};

CFATTACH_DECL_NEW(oak, sizeof(struct oak_softc),
    oak_match, oak_attach, NULL, NULL);

/*
 * Card probe function
 *
 * Just match the manufacturer and podule ID's
 */

int
oak_match(device_t parent, cfdata_t cf, void *aux)
{
        struct podulebus_attach_args *pa = aux;

        if (pa->pa_product == PODULE_OAK_SCSI)
                return 1;

        /* PowerROM */
        if (pa->pa_product == PODULE_ALSYSTEMS_SCSI &&
            podulebus_initloader(pa) == 0 &&
            podloader_callloader(pa, 0, 0) == PRID_OAK_SCSI1)
                return 1;

        return 0;
}

/*
 * Card attach function
 *
 */

void
oak_attach(device_t parent, device_t self, void *aux)
{
        struct oak_softc *sc = device_private(self);
        struct ncr5380_softc *ncr_sc = &sc->sc_ncr5380;
        struct podulebus_attach_args *pa = aux;
#ifndef NCR5380_USE_BUS_SPACE
        uint8_t *iobase;
#endif
        char hi_option[sizeof(device_xname(self)) + 8];

        ncr_sc->sc_dev = self;
        ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
        ncr_sc->sc_min_dma_len = 0;
        ncr_sc->sc_no_disconnect = 0xff;
        ncr_sc->sc_parity_disable = 0;

        ncr_sc->sc_dma_alloc = NULL;
        ncr_sc->sc_dma_free = NULL;
        ncr_sc->sc_dma_poll = NULL;
        ncr_sc->sc_dma_setup = NULL;
        ncr_sc->sc_dma_start = NULL;
        ncr_sc->sc_dma_eop = NULL;
        ncr_sc->sc_dma_stop = NULL;
        ncr_sc->sc_intr_on = NULL;
        ncr_sc->sc_intr_off = NULL;

#ifdef NCR5380_USE_BUS_SPACE
        ncr_sc->sc_regt = pa->pa_mod_t;
        bus_space_map(ncr_sc->sc_regt, pa->pa_mod_base, 8, 0,
            &ncr_sc->sc_regh);
        ncr_sc->sci_r0 = 0;
        ncr_sc->sci_r1 = 1;
        ncr_sc->sci_r2 = 2;
        ncr_sc->sci_r3 = 3;
        ncr_sc->sci_r4 = 4;
        ncr_sc->sci_r5 = 5;
        ncr_sc->sci_r6 = 6;
        ncr_sc->sci_r7 = 7;
#else
        iobase = (uint8_t *)pa->pa_mod_base;
        ncr_sc->sci_r0 = iobase + 0;
        ncr_sc->sci_r1 = iobase + 4;
        ncr_sc->sci_r2 = iobase + 8;
        ncr_sc->sci_r3 = iobase + 12;
        ncr_sc->sci_r4 = iobase + 16;
        ncr_sc->sci_r5 = iobase + 20;
        ncr_sc->sci_r6 = iobase + 24;
        ncr_sc->sci_r7 = iobase + 28;
#endif
        sc->sc_pdmat = pa->pa_mod_t;
        bus_space_map(sc->sc_pdmat, pa->pa_mod_base + OAK_PDMA_OFFSET, 0x20, 0,
            &sc->sc_pdmah);

        ncr_sc->sc_rev = NCR_VARIANT_NCR5380;

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

        /* Provide an override for the host id */
        ncr_sc->sc_channel.chan_id = 7;
        snprintf(hi_option, sizeof(hi_option), "%s.hostid",
            device_xname(self));
        (void)get_bootconf_option(boot_args, hi_option,
            BOOTOPT_TYPE_INT, &ncr_sc->sc_channel.chan_id);
        ncr_sc->sc_adapter.adapt_minphys = minphys;

        aprint_normal(": host=%d, using 8 bit PIO\n",
            ncr_sc->sc_channel.chan_id);

        ncr5380_attach(ncr_sc);
}

/*
 * XXX The code below doesn't work correctly.  I probably need more
 * details on how the card works.  [bjh21 20011202]
 */
#if 0

#ifndef OAK_TSIZE_OUT
#define OAK_TSIZE_OUT   128
#endif

#ifndef OAK_TSIZE_IN
#define OAK_TSIZE_IN    128
#endif

#define TIMEOUT 1000000

static inline int
oak_ready(struct ncr5380_softc *sc)
{
        int i;
        int status;

        for (i = TIMEOUT; i > 0; i--) {
                status = NCR5380_READ(sc, sci_csr);
                    if ((status & (SCI_CSR_DREQ | SCI_CSR_PHASE_MATCH)) ==
                        (SCI_CSR_DREQ | SCI_CSR_PHASE_MATCH))
                        return 1;

                if ((status & SCI_CSR_PHASE_MATCH) == 0 ||
                    SCI_BUSY(sc) == 0)
                        return 0;
        }
        printf("%s: ready timeout\n", device_xname(sc->sc_dev));
        return 0;

#if 0 /* The Linux driver does this: */
        struct oak_softc *sc = (void *)ncr_sc;
        bus_space_tag_t pdmat = sc->sc_pdmat;
        bus_space_handle_t pdmah = sc->sc_pdmah;
        int i, status;

        for (i = TIMEOUT; i > 0; i--) {
                status = bus_space_read_2(pdmat, pdmah, OAK_PDMA_STATUS);
                if (status & 0x200)
                        return 0;
                if (status & 0x100)
                        return 1;
        }
        printf("%s: ready timeout, status = 0x%x\n",
            device_xname(ncr_sc->sc_dev), status);
        return 0;
#endif
}



/* Return zero on success. */
static inline void oak_wait_not_req(struct ncr5380_softc *sc)
{
        int timo;
        for (timo = TIMEOUT; timo; timo--) {
                if ((NCR5380_READ(sc, sci_bus_csr) & SCI_BUS_REQ) == 0 ||
                    (NCR5380_READ(sc, sci_csr) & SCI_CSR_PHASE_MATCH) == 0 ||
                    SCI_BUSY(sc) == 0) {
                        return;
                }
        }
        printf("%s: pdma not_req timeout\n", device_xname(sc->sc_dev));
}

static int
oak_pdma_in(struct ncr5380_softc *ncr_sc, int phase, int datalen,
    uint8_t *data)
{
        struct oak_softc *sc = (void *)ncr_sc;
        bus_space_tag_t pdmat = sc->sc_pdmat;
        bus_space_handle_t pdmah = sc->sc_pdmah;
        int s, resid, len;

        s = splbio();

        NCR5380_WRITE(ncr_sc, sci_mode,
            NCR5380_READ(ncr_sc, sci_mode) | SCI_MODE_DMA);
        NCR5380_WRITE(ncr_sc, sci_irecv, 0);

        resid = datalen;
        while (resid > 0) {
                len = uimin(resid, OAK_TSIZE_IN);
                if (oak_ready(ncr_sc) == 0)
                        goto interrupt;
                KASSERT(BUS_SPACE_ALIGNED_POINTER(data, uint16_t));
                bus_space_read_multi_2(pdmat, pdmah, OAK_PDMA_READ,
                    (uint16_t *)data, len / 2);
                data += len;
                resid -= len;
        }

        oak_wait_not_req(ncr_sc);

interrupt:
        SCI_CLR_INTR(ncr_sc);
        NCR5380_WRITE(ncr_sc, sci_mode,
            NCR5380_READ(ncr_sc, sci_mode) & ~SCI_MODE_DMA);
        splx(s);
        return datalen - resid;
}

static int
oak_pdma_out(struct ncr5380_softc *ncr_sc, int phase, int datalen,
    uint8_t *data)
{
        struct oak_softc *sc = (struct oak_softc *)ncr_sc;
        bus_space_tag_t pdmat = sc->sc_pdmat;
        bus_space_handle_t pdmah = sc->sc_pdmah;
        int i, s, icmd, resid;

        s = splbio();
        icmd = NCR5380_READ(ncr_sc, sci_icmd) & SCI_ICMD_RMASK;
        NCR5380_WRITE(ncr_sc, sci_icmd, icmd | SCI_ICMD_DATA);
        NCR5380_WRITE(ncr_sc, sci_mode,
            NCR5380_READ(ncr_sc, sci_mode) | SCI_MODE_DMA);
        NCR5380_WRITE(ncr_sc, sci_dma_send, 0);

        resid = datalen;
        if (oak_ready(ncr_sc) == 0)
                goto interrupt;

        if (resid > OAK_TSIZE_OUT) {
                /*
                 * Because of the chips DMA prefetch, phase changes
                 * etc, won't be detected until we have written at
                 * least one byte more. We pre-write 4 bytes so
                 * subsequent transfers will be aligned to a 4 byte
                 * boundary. Assuming disconnects will only occur on
                 * block boundaries, we then correct for the pre-write
                 * when and if we get a phase change. If the chip had
                 * DMA byte counting hardware, the assumption would not
                 * be necessary.
                 */
                KASSERT(BUS_SPACE_ALIGNED_POINTER(data, uint16_t));
                bus_space_write_multi_2(pdmat, pdmah, OAK_PDMA_WRITE,
                    (uint16_t *)data, 4 / 2);
                data += 4;
                resid -= 4;

                for (; resid >= OAK_TSIZE_OUT; resid -= OAK_TSIZE_OUT) {
                        if (oak_ready(ncr_sc) == 0) {
                                resid += 4; /* Overshot */
                                goto interrupt;
                        }
                        bus_space_write_multi_2(pdmat, pdmah, OAK_PDMA_WRITE,
                            (uint16_t *)data, OAK_TSIZE_OUT / 2);
                        data += OAK_TSIZE_OUT;
                }
                if (oak_ready(ncr_sc) == 0) {
                        resid += 4; /* Overshot */
                        goto interrupt;
                }
        }

        if (resid) {
                bus_space_write_multi_2(pdmat, pdmah, OAK_PDMA_WRITE,
                    (uint16_t *)data, resid / 2);
                resid = 0;
        }
        for (i = TIMEOUT; i > 0; i--) {
                if ((NCR5380_READ(ncr_sc, sci_csr)
                    & (SCI_CSR_DREQ|SCI_CSR_PHASE_MATCH))
                    != SCI_CSR_DREQ)
                        break;
        }
        if (i != 0)
                bus_space_write_2(pdmat, pdmah, OAK_PDMA_WRITE, 0);
        else
                printf("%s: timeout waiting for final SCI_DSR_DREQ.\n",
                    device_xname(ncr_sc->sc_dev));

        oak_wait_not_req(ncr_sc);
interrupt:
        SCI_CLR_INTR(ncr_sc);
        NCR5380_WRITE(ncr_sc, sci_mode,
            NCR5380_READ(ncr_sc, sci_mode) & ~SCI_MODE_DMA);
        NCR5380_WRITE(ncr_sc, sci_icmd, icmd);
        splx(s);
        return datalen - resid;
}
#endif