/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003 Matthew N. Dodd <winter@jurai.net>
 * 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/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>

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

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

/* And all this for BIOS_PADDRTOVADDR() */
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <machine/md_var.h>
#include <machine/pc/bios.h>

#include <machine/smapi.h>

#define SMAPI_START     0xf0000
#define SMAPI_STEP      0x10
#define SMAPI_OFF       0
#define SMAPI_LEN       4
#define SMAPI_SIG       "$SMB"

#define RES2HDR(res)    ((struct smapi_bios_header *)rman_get_virtual(res))
#define ADDR2HDR(addr)  ((struct smapi_bios_header *)BIOS_PADDRTOVADDR(addr))

struct smapi_softc {
        struct cdev *           cdev;
        device_t                dev;
        struct resource *       res;
        int                     rid;

        u_int32_t               smapi32_entry;

        struct smapi_bios_header *header;
};

extern u_long smapi32_offset;
extern u_short smapi32_segment;

static d_ioctl_t smapi_ioctl;

static struct cdevsw smapi_cdevsw = {
        .d_version =    D_VERSION,
        .d_ioctl =      smapi_ioctl,
        .d_name =       "smapi",
        .d_flags =      D_NEEDGIANT,
};

static void     smapi_identify(driver_t *, device_t);
static int      smapi_probe(device_t);
static int      smapi_attach(device_t);
static int      smapi_detach(device_t);
static int      smapi_modevent(module_t, int, void *);
                
static int      smapi_header_cksum(struct smapi_bios_header *);

extern int      smapi32(struct smapi_bios_parameter *,
                    struct smapi_bios_parameter *);
extern int      smapi32_new(u_long, u_short,
                    struct smapi_bios_parameter *,
                    struct smapi_bios_parameter *);

static int
smapi_ioctl (struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
{
        struct smapi_softc *sc = dev->si_drv1;
        int error;

        switch (cmd) {
        case SMAPIOGHEADER:
                bcopy((caddr_t)sc->header, data,
                                sizeof(struct smapi_bios_header)); 
                error = 0;
                break;
        case SMAPIOCGFUNCTION:
                smapi32_offset = sc->smapi32_entry;
                error = smapi32((struct smapi_bios_parameter *)data,
                                (struct smapi_bios_parameter *)data);
                break;
        default:
                error = ENOTTY;
        }

        return (error);
}

static int
smapi_header_cksum (struct smapi_bios_header *header)
{
        u_int8_t *ptr;
        u_int8_t cksum;
        int i;

        ptr = (u_int8_t *)header;
        cksum = 0;
        for (i = 0; i < header->length; i++) {
                cksum += ptr[i];        
        }

        return (cksum);
}

static void
smapi_identify (driver_t *driver, device_t parent)
{
        device_t child;
        u_int32_t addr;
        int length;
        int rid;

        if (!device_is_alive(parent))
                return;

        addr = bios_sigsearch(SMAPI_START, SMAPI_SIG, SMAPI_LEN,
                              SMAPI_STEP, SMAPI_OFF);
        if (addr != 0) {
                rid = 0;
                length = ADDR2HDR(addr)->length;

                child = BUS_ADD_CHILD(parent, 5, "smapi", DEVICE_UNIT_ANY);
                device_set_driver(child, driver);
                bus_set_resource(child, SYS_RES_MEMORY, rid, addr, length);
                device_set_desc(child, "SMAPI BIOS");
        }

        return;
}

static int
smapi_probe (device_t dev)
{
        struct resource *res;
        int rid;
        int error;

        error = 0;
        rid = 0;
        res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
        if (res == NULL) {
                device_printf(dev, "Unable to allocate memory resource.\n");
                error = ENOMEM;
                goto bad;
        }

        if (smapi_header_cksum(RES2HDR(res))) {
                device_printf(dev, "SMAPI header checksum failed.\n");
                error = ENXIO;
                goto bad;
        }

bad:
        if (res)
                bus_release_resource(dev, SYS_RES_MEMORY, rid, res);
        return (error);
}

static int
smapi_attach (device_t dev)
{
        struct make_dev_args args;
        struct smapi_softc *sc;
        int error;

        sc = device_get_softc(dev);
        error = 0;

        sc->dev = dev;
        sc->rid = 0;
        sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->rid,
                 RF_ACTIVE);
        if (sc->res == NULL) {
                device_printf(dev, "Unable to allocate memory resource.\n");
                error = ENOMEM;
                goto bad;
        }
        sc->header = (struct smapi_bios_header *)rman_get_virtual(sc->res);
        sc->smapi32_entry = (u_int32_t)BIOS_PADDRTOVADDR(
                                        sc->header->prot32_segment +
                                        sc->header->prot32_offset);

        make_dev_args_init(&args);
        args.mda_devsw = &smapi_cdevsw;
        args.mda_uid = UID_ROOT;
        args.mda_gid = GID_WHEEL;
        args.mda_mode = 0600;
        args.mda_si_drv1 = sc;
        error = make_dev_s(&args, &sc->cdev, "%s%d",
                        smapi_cdevsw.d_name,
                        device_get_unit(sc->dev));
        if (error != 0)
                goto bad;

        device_printf(dev, "Version: %d.%02d, Length: %d, Checksum: 0x%02x\n",
                bcd2bin(sc->header->version_major),
                bcd2bin(sc->header->version_minor),
                sc->header->length,
                sc->header->checksum);
        device_printf(dev, "Information=0x%b\n",
                sc->header->information,
                "\020"
                "\001REAL_VM86"
                "\002PROTECTED_16"
                "\003PROTECTED_32");

        if (bootverbose) {
                if (sc->header->information & SMAPI_REAL_VM86)
                        device_printf(dev, "Real/VM86 mode: Segment 0x%04x, Offset 0x%04x\n",
                                sc->header->real16_segment,
                                sc->header->real16_offset);
                if (sc->header->information & SMAPI_PROT_16BIT)
                        device_printf(dev, "16-bit Protected mode: Segment 0x%08x, Offset 0x%04x\n",
                                sc->header->prot16_segment,
                                sc->header->prot16_offset);
                if (sc->header->information & SMAPI_PROT_32BIT)
                        device_printf(dev, "32-bit Protected mode: Segment 0x%08x, Offset 0x%08x\n",
                                sc->header->prot32_segment,
                                sc->header->prot32_offset);
        }

        return (0);
bad:
        if (sc->res)
                bus_release_resource(dev, SYS_RES_MEMORY, sc->rid, sc->res);
        return (error);
}

static int
smapi_detach (device_t dev)
{
        struct smapi_softc *sc;

        sc = device_get_softc(dev);

        destroy_dev(sc->cdev);

        if (sc->res)
                bus_release_resource(dev, SYS_RES_MEMORY, sc->rid, sc->res);

        return (0);
}

static device_method_t smapi_methods[] = {
        /* Device interface */
        DEVMETHOD(device_identify,      smapi_identify),
        DEVMETHOD(device_probe,         smapi_probe),
        DEVMETHOD(device_attach,        smapi_attach),
        DEVMETHOD(device_detach,        smapi_detach),
        { 0, 0 }
};

static driver_t smapi_driver = {
        "smapi",
        smapi_methods,
        sizeof(struct smapi_softc),
};

static int
smapi_modevent (module_t mod, int what, void *arg)
{
        device_t *      devs;
        int             count;
        int             i;

        switch (what) {
        case MOD_LOAD:
                break;
        case MOD_UNLOAD:
                devclass_get_devices(devclass_find(smapi_driver.name), &devs,
                    &count);
                for (i = 0; i < count; i++) {
                        device_delete_child(device_get_parent(devs[i]), devs[i]);
                }
                free(devs, M_TEMP);
                break;
        default:
                break;
        }

        return (0);
}

DRIVER_MODULE(smapi, nexus, smapi_driver, smapi_modevent, NULL);
MODULE_VERSION(smapi, 1);