/*      $NetBSD: sram.c,v 1.23 2025/01/27 21:20:25 andvar Exp $ */

/*
 * Copyright (c) 1994 Kazuhisa Shimizu.
 * All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Kazuhisa Shimizu.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
__KERNEL_RCSID(0, "$NetBSD: sram.c,v 1.23 2025/01/27 21:20:25 andvar Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/device.h>

#include <machine/sram.h>
#include <x68k/dev/intiovar.h>
#include <x68k/dev/sramvar.h>

#include "ioconf.h"

#define SRAM_ADDR       (0xed0000)

#ifdef DEBUG
#define SRAM_DEBUG_OPEN         0x01
#define SRAM_DEBUG_CLOSE        0x02
#define SRAM_DEBUG_IOCTL        0x04
#define SRAM_DEBUG_DONTDOIT     0x08
int sramdebug = SRAM_DEBUG_IOCTL;
#define DPRINTF(flag, msg)      do {    \
        if ((sramdebug & (flag)))       \
                printf msg;             \
} while (0)
#else
#define DPRINTF(flag, msg)      /* nothing */
#endif

int  srammatch(device_t, cfdata_t, void *);
void sramattach(device_t, device_t, void *);

dev_type_open(sramopen);
dev_type_close(sramclose);
dev_type_ioctl(sramioctl);

CFATTACH_DECL_NEW(sram, sizeof(struct sram_softc),
        srammatch, sramattach, NULL, NULL);

const struct cdevsw sram_cdevsw = {
        .d_open = sramopen,
        .d_close = sramclose,
        .d_read = noread,
        .d_write = nowrite,
        .d_ioctl = sramioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = 0
};

static int sram_attached;

/*
 *  functions for probing.
 */
int
srammatch(device_t parent, cfdata_t cf, void *aux)
{
        struct intio_attach_args *ia = aux;

        if (sram_attached)
                return 0;

        if (ia->ia_addr == INTIOCF_ADDR_DEFAULT)
                ia->ia_addr = SRAM_ADDR;

        /* Fixed parameter */
        if (ia->ia_addr != SRAM_ADDR)
                return 0;

        return 1;
}

void
sramattach(device_t parent, device_t self, void *aux)
{
        struct sram_softc *sc = device_private(self);
        struct intio_attach_args *ia = aux;
        bus_space_tag_t iot;
        bus_space_handle_t ioh;

        /* Map I/O space */
        iot = ia->ia_bst;
        if (bus_space_map(iot, ia->ia_addr, SRAM_SIZE, 0, &ioh))
                goto out;

        /* Initialize sc */
        sc->sc_iot = iot;
        sc->sc_ioh = ioh;

        sc->sc_flags = 0;
        aprint_normal(": 16k bytes accessible\n");
        sram_attached = 1;
        return;

 out:
        aprint_normal(": not accessible\n");
}


/*ARGSUSED*/
int
sramopen(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct sram_softc *sc;

        DPRINTF(SRAM_DEBUG_OPEN, ("Sram open\n"));

        sc = device_lookup_private(&sram_cd, minor(dev));
        if (sc == NULL)
                return ENXIO;

        if (sc->sc_flags & SRF_OPEN)
                return EBUSY;

        sc->sc_flags |= SRF_OPEN;
        if (flags & FREAD)
                sc->sc_flags |= SRF_READ;
        if (flags & FWRITE)
                sc->sc_flags |= SRF_WRITE;

        return 0;
}

/*ARGSUSED*/
int
sramclose(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct sram_softc *sc;

        DPRINTF(SRAM_DEBUG_CLOSE, ("Sram close\n"));

        sc = device_lookup_private(&sram_cd, minor(dev));
        if (sc == NULL)
                return ENXIO;

        if (sc->sc_flags & SRF_OPEN) {
                sc->sc_flags = 0;
        }
        sc->sc_flags &= ~(SRF_READ|SRF_WRITE);

        return 0;
}

/*ARGSUSED*/
int
sramioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        int error = 0;
        struct sram_io *sram_io;
        struct sram_softc *sc;

        DPRINTF(SRAM_DEBUG_IOCTL, ("Sram ioctl cmd=%lx\n", cmd));

        sc = device_lookup_private(&sram_cd, minor(dev));
        if (sc == NULL)
                return ENXIO;

        sram_io = (struct sram_io *)data;
        if (sram_io == NULL)
                return EFAULT;

        switch (cmd) {
        case SIOGSRAM:
                if ((sc->sc_flags & SRF_READ) == 0)
                        return EPERM;
                DPRINTF(SRAM_DEBUG_IOCTL,
                        ("Sram ioctl SIOGSRAM address=%p\n", data));
                DPRINTF(SRAM_DEBUG_IOCTL,
                        ("Sram ioctl SIOGSRAM offset=%x\n", sram_io->offset));
                if (sram_io->offset + SRAM_IO_SIZE > SRAM_SIZE)
                        return EFAULT;
                bus_space_read_region_1(sc->sc_iot, sc->sc_ioh, sram_io->offset,
                        (uint8_t *)&sram_io->sram, SRAM_IO_SIZE);
                break;
        case SIOPSRAM:
                if ((sc->sc_flags & SRF_WRITE) == 0)
                        return EPERM;
                DPRINTF(SRAM_DEBUG_IOCTL,
                        ("Sram ioctl SIOPSRAM address=%p\n", data));
                DPRINTF(SRAM_DEBUG_IOCTL,
                        ("Sram ioctl SIOPSRAM offset=%x\n", sram_io->offset));
                if (sram_io->offset + SRAM_IO_SIZE > SRAM_SIZE)
                        return EFAULT;
#ifdef DEBUG
                if (sramdebug & SRAM_DEBUG_DONTDOIT) {
                        printf("Sram ioctl SIOPSRAM: skipping actual write\n");
                        break;
                }
#endif
                intio_set_sysport_sramwp(0x31);
                bus_space_write_region_1(sc->sc_iot, sc->sc_ioh,
                        sram_io->offset, (uint8_t *)&sram_io->sram,
                        SRAM_IO_SIZE);
                intio_set_sysport_sramwp(0x00);
                break;
        default:
                error = EINVAL;
                break;
        }
        return error;
}