/* $NetBSD: xp.c,v 1.8 2023/01/15 05:08:33 tsutsui Exp $ */

/*-
 * Copyright (c) 2016 Izumi Tsutsui.  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.
 *
 * 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.
 */

/*
 * LUNA's Hitachi HD647180 "XP" I/O processor driver
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xp.c,v 1.8 2023/01/15 05:08:33 tsutsui Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/kmem.h>
#include <sys/mman.h>
#include <sys/errno.h>

#include <uvm/uvm_extern.h>

#include <machine/autoconf.h>
#include <machine/board.h>
#include <machine/xpio.h>

#include <luna68k/dev/xpbusvar.h>

#include "ioconf.h"
#include "xplx/xplxdefs.h"

struct xp_softc {
        device_t        sc_dev;

        vaddr_t         sc_shm_base;
        vsize_t         sc_shm_size;
        vaddr_t         sc_tas;

        bool            sc_isopen;
        int             sc_flags;
};

static int xp_match(device_t, cfdata_t, void *);
static void xp_attach(device_t, device_t, void *);

static dev_type_open(xp_open);
static dev_type_close(xp_close);
static dev_type_read(xp_read);
static dev_type_write(xp_write);
static dev_type_ioctl(xp_ioctl);
static dev_type_mmap(xp_mmap);

const struct cdevsw xp_cdevsw = {
        .d_open     = xp_open,
        .d_close    = xp_close,
        .d_read     = xp_read,
        .d_write    = xp_write,
        .d_ioctl    = xp_ioctl,
        .d_stop     = nostop,
        .d_tty      = notty,
        .d_poll     = nopoll,
        .d_mmap     = xp_mmap,
        .d_kqfilter = nokqfilter,
        .d_discard  = nodiscard,
        .d_flag     = 0
};

CFATTACH_DECL_NEW(xp, sizeof(struct xp_softc),
    xp_match, xp_attach, NULL, NULL);

/* #define XP_DEBUG */

#ifdef XP_DEBUG
#define XP_DEBUG_ALL    0xff
uint32_t xp_debug = 0;
#define DPRINTF(x, y)   if (xp_debug & (x)) printf y
#else
#define DPRINTF(x, y)   /* nothing */
#endif

static bool xp_matched;

static int
xp_match(device_t parent, cfdata_t cf, void *aux)
{
        struct xpbus_attach_args *xa = aux;

        /* only one XP processor */
        if (xp_matched)
                return 0;

        if (strcmp(xa->xa_name, xp_cd.cd_name))
                return 0;

        xp_matched = true;
        return 1;
}

static void
xp_attach(device_t parent, device_t self, void *aux)
{
        struct xp_softc *sc = device_private(self);

        sc->sc_dev = self;

        aprint_normal(": HD647180X I/O processor\n");

        sc->sc_shm_base = XP_SHM_BASE;
        sc->sc_shm_size = XP_SHM_SIZE;
        sc->sc_tas      = XP_TAS_ADDR;
}

static int
xp_open(dev_t dev, int flags, int devtype, struct lwp *l)
{
        struct xp_softc *sc;
        int unit;
        u_int a;

        DPRINTF(XP_DEBUG_ALL, ("%s\n", __func__));

        unit = minor(dev);
        sc = device_lookup_private(&xp_cd, unit);
        if (sc == NULL)
                return ENXIO;
        if (sc->sc_isopen)
                return EBUSY;

        if ((flags & FWRITE) != 0) {
                /* exclusive if write */
                a = xp_acquire(DEVID_XPBUS, XP_ACQ_EXCL);
                if (a == 0)
                        return EBUSY;
                if (a != (1 << DEVID_XPBUS)) {
                        xp_release(DEVID_XPBUS);
                        return EBUSY;
                }
        } else {
                a = xp_acquire(DEVID_XPBUS, 0);
                if (a == 0)
                        return EBUSY;
        }

        sc->sc_isopen = true;
        sc->sc_flags = flags;

        return 0;
}

static int
xp_close(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct xp_softc *sc;
        int unit;

        DPRINTF(XP_DEBUG_ALL, ("%s\n", __func__));

        unit = minor(dev);
        sc = device_lookup_private(&xp_cd, unit);

        xp_release(DEVID_XPBUS);

        sc->sc_isopen = false;

        return 0;
}

static int
xp_ioctl(dev_t dev, u_long cmd, void *addr, int flags, struct lwp *l)
{
        struct xp_softc *sc;
        int unit, error;
        struct xp_download *downld;
        uint8_t *loadbuf;
        size_t loadsize;

        DPRINTF(XP_DEBUG_ALL, ("%s\n", __func__));

        unit = minor(dev);
        sc = device_lookup_private(&xp_cd, unit);

        switch (cmd) {
        case XPIOCDOWNLD:
                if ((sc->sc_flags & FWRITE) == 0) {
                        return EACCES;
                }
                downld = addr;
                loadsize = downld->size;
                if (loadsize == 0 || loadsize > sc->sc_shm_size) {
                        return EINVAL;
                }

                loadbuf = kmem_alloc(loadsize, KM_SLEEP);
                error = copyin(downld->data, loadbuf, loadsize);
                if (error == 0) {
                        xp_set_shm_dirty();
                        xp_cpu_reset_hold();
                        delay(100);
                        memcpy((void *)sc->sc_shm_base, loadbuf, loadsize);
                        delay(100);
                        xp_cpu_reset_release();
                } else {
                        DPRINTF(XP_DEBUG_ALL, ("%s: ioctl failed (err =  %d)\n",
                            __func__, error));
                }

                kmem_free(loadbuf, loadsize);
                return error;

        default:
                return ENOTTY;
        }

        panic("%s: cmd (%ld) is not handled", device_xname(sc->sc_dev), cmd);
}

static paddr_t
xp_mmap(dev_t dev, off_t offset, int prot)
{
        struct xp_softc *sc;
        int unit;
        paddr_t pa;

        pa = -1;

        unit = minor(dev);
        sc = device_lookup_private(&xp_cd, unit);

        if (offset >= 0 &&
            offset < sc->sc_shm_size) {
                pa = m68k_btop(m68k_trunc_page(sc->sc_shm_base) + offset);
        }

        if ((prot & PROT_WRITE) != 0)
                xp_set_shm_dirty();

        return pa;
}

static int
xp_read(dev_t dev, struct uio *uio, int flags)
{

        return ENODEV;
}

static int
xp_write(dev_t dev, struct uio *uio, int flags)
{

        return ENODEV;
}