/*      $NetBSD: ofrom.c,v 1.29 2021/01/27 03:10:21 thorpej Exp $       */

/*
 * Copyright 1998
 * Digital Equipment Corporation. All rights reserved.
 *
 * This software is furnished under license and may be used and
 * copied only in accordance with the following terms and conditions.
 * Subject to these conditions, you may download, copy, install,
 * use, modify and distribute this software in source and/or binary
 * form. No title or ownership is transferred hereby.
 *
 * 1) Any source code used, modified or distributed must reproduce
 *    and retain this copyright notice and list of conditions as
 *    they appear in the source file.
 *
 * 2) No right is granted to use any trade name, trademark, or logo of
 *    Digital Equipment Corporation. Neither the "Digital Equipment
 *    Corporation" name nor any trademark or logo of Digital Equipment
 *    Corporation may be used to endorse or promote products derived
 *    from this software without the prior written permission of
 *    Digital Equipment Corporation.
 *
 * 3) This software is provided "AS-IS" and any express or implied
 *    warranties, including but not limited to, any implied warranties
 *    of merchantability, fitness for a particular purpose, or
 *    non-infringement are disclaimed. In no event shall DIGITAL be
 *    liable for any damages whatsoever, and in particular, DIGITAL
 *    shall not be liable for special, indirect, consequential, or
 *    incidental damages or damages for lost profits, loss of
 *    revenue or loss of use, whether such damages arise in contract,
 *    negligence, tort, under statute, in equity, at law or otherwise,
 *    even if advised of the possibility of such damage.
 */

/*
 * XXX open for writing (for user programs to mmap, and write contents)
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ofrom.c,v 1.29 2021/01/27 03:10:21 thorpej Exp $");

#include <sys/param.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/bus.h>

#include <uvm/uvm_extern.h>

#include <dev/ofw/openfirm.h>

struct ofrom_softc {
        int             enabled;
        paddr_t         base;
        paddr_t         size;
};

int ofromprobe(device_t, cfdata_t, void *);
void ofromattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(ofrom, sizeof(struct ofrom_softc),
    ofromprobe, ofromattach, NULL, NULL);

extern struct cfdriver ofrom_cd;

dev_type_open(ofromopen);
dev_type_read(ofromrw);
dev_type_mmap(ofrommmap);

const struct cdevsw ofrom_cdevsw = {
        .d_open = ofromopen,
        .d_close = nullclose,
        .d_read = ofromrw,
        .d_write = ofromrw,
        .d_ioctl = noioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = ofrommmap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = 0
};

static const struct device_compatible_entry compat_data[] = {
        { .compat = "rom" },
        DEVICE_COMPAT_EOL
};

int
ofromprobe(device_t parent, cfdata_t cf, void *aux)
{
        struct ofbus_attach_args *oba = aux;

        return of_compatible_match(oba->oba_phandle, compat_data) * 5;
}


void
ofromattach(device_t parent, device_t self, void *aux)
{
        struct ofrom_softc *sc = device_private(self);
        struct ofbus_attach_args *oba = aux;
        char regbuf[8];

        if (OF_getproplen(oba->oba_phandle, "reg") != 8) {
                printf(": invalid reg property\n");
                return;
        }
        if (OF_getprop(oba->oba_phandle, "reg", regbuf, sizeof regbuf) != 8) {
                printf(": couldn't read reg property\n");
                return;
        }
        sc->base = of_decode_int(&regbuf[0]);
        sc->size = of_decode_int(&regbuf[4]);
        sc->enabled = 1;

        printf(": %#lx-%#lx\n", sc->base, sc->base + sc->size - 1);
}

int
ofromopen(dev_t dev, int oflags, int devtype, struct lwp *l)
{
        struct ofrom_softc *sc;

        sc = device_lookup_private(&ofrom_cd, minor(dev));
        if (!sc || !sc->enabled)
                return (ENXIO);

        if (oflags & FWRITE)
                return (EINVAL);

        return (0);
}

int
ofromrw(dev_t dev, struct uio *uio, int flags)
{
        pmap_t kpm = pmap_kernel();
        struct ofrom_softc *sc;
        int c, error = 0;
        struct iovec *iov;
        paddr_t v;
        psize_t o;
        extern kmutex_t memlock;
        extern char *memhook;

        sc = device_lookup_private(&ofrom_cd, minor(dev));
        if (!sc || !sc->enabled)
                return (ENXIO);                 /* XXX PANIC */

        mutex_enter(&memlock);
        while (uio->uio_resid > 0 && error == 0) {
                iov = uio->uio_iov;
                if (iov->iov_len == 0) {
                        uio->uio_iov++;
                        uio->uio_iovcnt--;
                        if (uio->uio_iovcnt < 0)
                                panic("ofromrw");
                        continue;
                }

                /*
                 * Since everything is page aligned and no more
                 * than the rest of a page is done at once, we
                 * can just check that the offset isn't too big.
                 */
                if (uio->uio_offset >= sc->size)
                        break;

                v = sc->base + uio->uio_offset;
                pmap_kenter_pa((vaddr_t)memhook, trunc_page(v),
                    uio->uio_rw == UIO_READ ?  VM_PROT_READ : VM_PROT_WRITE,
                    0);
                pmap_update(kpm);
                o = uio->uio_offset & PGOFSET;
                c = uimin(uio->uio_resid, (int)(PAGE_SIZE - o));
                error = uiomove((char *)memhook + o, c, uio);
                pmap_kremove((vaddr_t)memhook, (vaddr_t)memhook + PAGE_SIZE);
                pmap_update(kpm);
        }
        mutex_exit(&memlock);

        return (error);
}

paddr_t
ofrommmap(dev_t dev, off_t off, int prot)
{
        struct ofrom_softc *sc;

        sc = device_lookup_private(&ofrom_cd, minor(dev));
        if (!sc || !sc->enabled)
                return (-1);                    /* XXX PANIC */

        if ((u_int)off >= sc->size)
                return (-1);

        return arm_btop(sc->base + off);
}