/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000 Nikolai Saoukh
 * 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 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 AUTHOR 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.
 */

#include <sys/cdefs.h>
/*
 * Driver to take care of holes in ISA I/O memory occupied
 * by option rom(s)
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/socket.h>

#include <sys/module.h>
#include <sys/bus.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>

#include <isa/isavar.h>
#include <isa/pnpvar.h>

#define IOMEM_START     0x0a0000
#define IOMEM_STEP      0x000800
#define IOMEM_END       0x100000

#define ORM_ID  0x00004d3e

static struct isa_pnp_id orm_ids[] = {
        { ORM_ID,       NULL },         /* ORM0000 */
        { 0,            NULL },
};

#define MAX_ROMS        32

struct orm_softc {
        int             rnum;
        int             rid[MAX_ROMS];
        struct resource *res[MAX_ROMS];
};

static int
orm_probe(device_t dev)
{
        return (ISA_PNP_PROBE(device_get_parent(dev), dev, orm_ids));
}

static int
orm_attach(device_t dev)
{
        return (0);
}

static void
orm_identify(driver_t* driver, device_t parent)
{
        bus_space_handle_t      bh;
        bus_space_tag_t         bt;
        device_t                child;
        u_int32_t               chunk = IOMEM_START;
        struct resource         *res;
        int                     rid;
        u_int32_t               rom_size;
        struct orm_softc        *sc;
        u_int8_t                buf[3];

        if (resource_disabled("orm", 0))
                return;

        child = BUS_ADD_CHILD(parent, ISA_ORDER_SENSITIVE, "orm", DEVICE_UNIT_ANY);
        device_set_driver(child, driver);
        isa_set_logicalid(child, ORM_ID);
        isa_set_vendorid(child, ORM_ID);
        sc = device_get_softc(child);
        sc->rnum = 0;
        while (sc->rnum < MAX_ROMS && chunk < IOMEM_END) {
                bus_set_resource(child, SYS_RES_MEMORY, sc->rnum, chunk,
                    IOMEM_STEP);
                rid = sc->rnum;
                res = bus_alloc_resource_any(child, SYS_RES_MEMORY, &rid,
                    RF_ACTIVE);
                if (res == NULL) {
                        bus_delete_resource(child, SYS_RES_MEMORY, sc->rnum);
                        chunk += IOMEM_STEP;
                        continue;
                }
                bt = rman_get_bustag(res);
                bh = rman_get_bushandle(res);
                bus_space_read_region_1(bt, bh, 0, buf, sizeof(buf));

                /*
                 * We need to release and delete the resource since we're
                 * changing its size, or the rom isn't there.  There
                 * is a checksum field in the ROM to prevent false
                 * positives.  However, some common hardware (IBM thinkpads)
                 * neglects to put a valid checksum in the ROM, so we do
                 * not double check the checksum here.  On the ISA bus
                 * areas that have no hardware read back as 0xff, so the
                 * tests to see if we have 0x55 followed by 0xaa are
                 * generally sufficient.
                 */
                bus_release_resource(child, SYS_RES_MEMORY, rid, res);
                bus_delete_resource(child, SYS_RES_MEMORY, sc->rnum);
                if (buf[0] != 0x55 || buf[1] != 0xAA || (buf[2] & 0x03) != 0) {
                        chunk += IOMEM_STEP;
                        continue;
                }
                rom_size = buf[2] << 9;
                bus_set_resource(child, SYS_RES_MEMORY, sc->rnum, chunk,
                    rom_size);
                rid = sc->rnum;
                res = bus_alloc_resource_any(child, SYS_RES_MEMORY, &rid, 0);
                if (res == NULL) {
                        bus_delete_resource(child, SYS_RES_MEMORY, sc->rnum);
                        chunk += IOMEM_STEP;
                        continue;
                }
                sc->rid[sc->rnum] = rid;
                sc->res[sc->rnum] = res;
                sc->rnum++;
                chunk += rom_size;
        }

        if (sc->rnum == 0)
                device_delete_child(parent, child);
        else if (sc->rnum == 1)
                device_set_desc(child, "ISA Option ROM");
        else
                device_set_desc(child, "ISA Option ROMs");
}

static int
orm_detach(device_t dev)
{
        int                     i;
        struct orm_softc        *sc = device_get_softc(dev);

        for (i = 0; i < sc->rnum; i++)
                bus_release_resource(dev, SYS_RES_MEMORY, sc->rid[i],
                    sc->res[i]);
        return (0);
}

static device_method_t orm_methods[] = {
        /* Device interface */
        DEVMETHOD(device_identify,      orm_identify),
        DEVMETHOD(device_probe,         orm_probe),
        DEVMETHOD(device_attach,        orm_attach),
        DEVMETHOD(device_detach,        orm_detach),
        { 0, 0 }
};

static driver_t orm_driver = {
        "orm",
        orm_methods,
        sizeof (struct orm_softc)
};

DRIVER_MODULE(orm, isa, orm_driver, 0, 0);
ISA_PNP_INFO(orm_ids);