/*      $NetBSD: esp.c,v 1.30 2024/12/20 23:52:00 tsutsui Exp $ */

/*-
* Copyright (c) 1997 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jeremy Cooper and Gordon W. Ross
*
* 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.
*/

/*
* "Front end" glue for the ncr53c9x chip, formerly known as the
* Emulex SCSI Processor (ESP) which is what we actually have.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: esp.c,v 1.30 2024/12/20 23:52:00 tsutsui Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/errno.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/scsipi/scsi_message.h>

#include <machine/autoconf.h>
#include <machine/bus.h>

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

#include <sun3/dev/dmareg.h>
#include <sun3/dev/dmavar.h>

#define ESP_REG_SIZE    (12*4)

struct esp_softc {
       struct ncr53c9x_softc sc_ncr53c9x;      /* glue to MI code */
       bus_space_tag_t sc_bst;                 /* bus space tag */
       bus_space_handle_t sc_bsh;              /* bus space handle */
       struct dma_softc *sc_dma;               /* pointer to my dma */
};

static int      espmatch(device_t, cfdata_t, void *);
static void     espattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(esp, sizeof(struct esp_softc),
   espmatch, espattach, NULL, NULL);

/*
* Functions and the switch for the MI code.
*/
static uint8_t  esp_read_reg(struct ncr53c9x_softc *, int);
static void     esp_write_reg(struct ncr53c9x_softc *, int, uint8_t);
static int      esp_dma_isintr(struct ncr53c9x_softc *);
static void     esp_dma_reset(struct ncr53c9x_softc *);
static int      esp_dma_intr(struct ncr53c9x_softc *);
static int      esp_dma_setup(struct ncr53c9x_softc *, uint8_t **, size_t *,
                   int, size_t *);
static void     esp_dma_go(struct ncr53c9x_softc *);
static void     esp_dma_stop(struct ncr53c9x_softc *);
static int      esp_dma_isactive(struct ncr53c9x_softc *);

static struct ncr53c9x_glue esp_glue = {
       esp_read_reg,
       esp_write_reg,
       esp_dma_isintr,
       esp_dma_reset,
       esp_dma_intr,
       esp_dma_setup,
       esp_dma_go,
       esp_dma_stop,
       esp_dma_isactive,
       NULL,                   /* gl_clear_latched_intr */
};

static int
espmatch(device_t parent, struct cfdata *cf, void *aux)
{
       struct confargs *ca = aux;

       /*
        * Check for the esp registers.
        */
       if (bus_peek(ca->ca_bustype,
           ca->ca_paddr + (NCR_STAT * 4), 1) == -1)
               return 0;

       /* If default ipl, fill it in. */
       if (ca->ca_intpri == -1)
               ca->ca_intpri = 2;

       return 1;
}

static void
espattach(device_t parent, device_t self, void *aux)
{
       struct esp_softc *esc = device_private(self);
       struct ncr53c9x_softc *sc = &esc->sc_ncr53c9x;
       struct confargs *ca = aux;

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

       /*
        * Map the ESP registers.
        */
       esc->sc_bst = ca->ca_bustag;
       if (bus_space_map(esc->sc_bst, ca->ca_paddr, ESP_REG_SIZE, 0,
           &esc->sc_bsh) != 0) {
               aprint_error(": can't map register\n");
               return;
       }

       /* Other settings */
       sc->sc_id = 7;
       sc->sc_freq = 20;       /* The 3/80 esp runs at 20 MHz */

       /*
        * Hook up the DMA driver.
        */
       esc->sc_dma = espdmafind(device_unit(self));
       esc->sc_dma->sc_client = sc; /* Point back to us */

       /*
        * 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...
        */

       /*
        * It is necessary to try to load the 2nd config register here,
        * to find out what rev the esp chip is, else the ncr53c9x_reset
        * will not set up the defaults correctly.
        */
       sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
       sc->sc_cfg2 = NCRCFG2_SCSI2 | NCRCFG2_RPE;
       sc->sc_cfg3 = NCRCFG3_CDB;
       NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);

       if ((NCR_READ_REG(sc, NCR_CFG2) & ~NCRCFG2_RSVD) !=
           (NCRCFG2_SCSI2 | NCRCFG2_RPE)) {
               sc->sc_rev = NCR_VARIANT_ESP100;
       } else {
               sc->sc_cfg2 = NCRCFG2_SCSI2;
               NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
               sc->sc_cfg3 = 0;
               NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
               sc->sc_cfg3 = (NCRCFG3_CDB | NCRCFG3_FCLK);
               NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
               if (NCR_READ_REG(sc, NCR_CFG3) !=
                   (NCRCFG3_CDB | NCRCFG3_FCLK)) {
                       sc->sc_rev = NCR_VARIANT_ESP100A;
               } else {
                       /* NCRCFG2_FE enables > 64K transfers */
                       sc->sc_cfg2 |= NCRCFG2_FE;
                       sc->sc_cfg3 = 0;
                       NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
                       sc->sc_rev = NCR_VARIANT_ESP200;
               }
       }

       /*
        * 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;

       /*
        * Alas, we must now modify the value a bit, because it's
        * only valid when can switch on FASTCLK and FASTSCSI bits
        * in config register 3...
        */
       switch (sc->sc_rev) {
       case NCR_VARIANT_ESP100:
               sc->sc_maxxfer = 64 * 1024;
               sc->sc_minsync = 0;     /* No synch on old chip? */
               break;

       case NCR_VARIANT_ESP100A:
               sc->sc_maxxfer = 64 * 1024;
               /* Min clocks/byte is 5 */
               sc->sc_minsync = ncr53c9x_cpb2stp(sc, 5);
               break;

       case NCR_VARIANT_ESP200:
               sc->sc_maxxfer = 16 * 1024 * 1024;
               /* XXX - do actually set FAST* bits */
               break;
       }

       /* and the interrupts */
       isr_add_autovect(ncr53c9x_intr, sc, ca->ca_intpri);
       evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
           device_xname(self), "intr");

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

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


/*
* Glue functions.
*/

uint8_t
esp_read_reg(struct ncr53c9x_softc *sc, int reg)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       return bus_space_read_1(esc->sc_bst, esc->sc_bsh, reg * 4);
}

void
esp_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t val)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       bus_space_write_1(esc->sc_bst, esc->sc_bsh, reg * 4, val);
}

int
esp_dma_isintr(struct ncr53c9x_softc *sc)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       return DMA_ISINTR(esc->sc_dma);
}

void
esp_dma_reset(struct ncr53c9x_softc *sc)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       dma_reset(esc->sc_dma);
}

int
esp_dma_intr(struct ncr53c9x_softc *sc)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       return espdmaintr(esc->sc_dma);
}

int
esp_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
   int datain, size_t *dmasize)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       return dma_setup(esc->sc_dma, addr, len, datain, dmasize);
}

void
esp_dma_go(struct ncr53c9x_softc *sc)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       DMA_GO(esc->sc_dma);
}

void
esp_dma_stop(struct ncr53c9x_softc *sc)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       DMA_STOP(esc->sc_dma);
}

int
esp_dma_isactive(struct ncr53c9x_softc *sc)
{
       struct esp_softc *esc = (struct esp_softc *)sc;

       return DMA_ISACTIVE(esc->sc_dma);
}