/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1998, 2001 Nicolas Souchu
 * Copyright (c) 2023 Juniper Networks, Inc.
 * 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/kernel.h>
#include <sys/systm.h>
#include <sys/abi_compat.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/fcntl.h>

#include <dev/smbus/smbconf.h>
#include <dev/smbus/smbus.h>
#include <dev/smbus/smb.h>

#include "smbus_if.h"

#ifdef COMPAT_FREEBSD32
struct smbcmd32 {
        u_char cmd;
        u_char reserved;
        u_short op;
        union {
                char    byte;
                char    buf[2];
                short   word;
        } wdata;
        union {
                char    byte;
                char    buf[2];
                short   word;
        } rdata;
        int slave;
        uint32_t wbuf;
        int wcount;
        uint32_t rbuf;
        int rcount;
};

#define SMB_QUICK_WRITE32       _IOW('i', 1, struct smbcmd32)
#define SMB_QUICK_READ32        _IOW('i', 2, struct smbcmd32)
#define SMB_SENDB32             _IOW('i', 3, struct smbcmd32)
#define SMB_RECVB32             _IOWR('i', 4, struct smbcmd32)
#define SMB_WRITEB32            _IOW('i', 5, struct smbcmd32)
#define SMB_WRITEW32            _IOW('i', 6, struct smbcmd32)
#define SMB_READB32             _IOWR('i', 7, struct smbcmd32)
#define SMB_READW32             _IOWR('i', 8, struct smbcmd32)
#define SMB_PCALL32             _IOWR('i', 9, struct smbcmd32)
#define SMB_BWRITE32            _IOW('i', 10, struct smbcmd32)
#define SMB_BREAD32             _IOWR('i', 11, struct smbcmd32)
#define SMB_OLD_READB32         _IOW('i', 7, struct smbcmd32)
#define SMB_OLD_READW32         _IOW('i', 8, struct smbcmd32)
#define SMB_OLD_PCALL32         _IOW('i', 9, struct smbcmd32)
#endif

#define SMB_OLD_READB   _IOW('i', 7, struct smbcmd)
#define SMB_OLD_READW   _IOW('i', 8, struct smbcmd)
#define SMB_OLD_PCALL   _IOW('i', 9, struct smbcmd)

struct smb_softc {
        device_t sc_dev;
        struct cdev *sc_devnode;
};

static void smb_identify(driver_t *driver, device_t parent);
static int smb_probe(device_t);
static int smb_attach(device_t);
static int smb_detach(device_t);

static device_method_t smb_methods[] = {
        /* device interface */
        DEVMETHOD(device_identify,      smb_identify),
        DEVMETHOD(device_probe,         smb_probe),
        DEVMETHOD(device_attach,        smb_attach),
        DEVMETHOD(device_detach,        smb_detach),

        /* smbus interface */
        DEVMETHOD(smbus_intr,           smbus_generic_intr),
        DEVMETHOD_END
};

static driver_t smb_driver = {
        "smb",
        smb_methods,
        sizeof(struct smb_softc),
};

static  d_ioctl_t       smbioctl;

static struct cdevsw smb_cdevsw = {
        .d_version =    D_VERSION,
        .d_flags =      D_TRACKCLOSE,
        .d_ioctl =      smbioctl,
        .d_name =       "smb",
};

static void
smb_identify(driver_t *driver, device_t parent)
{

        if (device_find_child(parent, "smb", DEVICE_UNIT_ANY) == NULL)
                BUS_ADD_CHILD(parent, 0, "smb", DEVICE_UNIT_ANY);
}

static int
smb_probe(device_t dev)
{
        if (smbus_get_addr(dev) != -1)
                return (ENXIO);

        device_set_desc(dev, "SMBus generic I/O");
        return (BUS_PROBE_NOWILDCARD);
}

static int
smb_attach(device_t dev)
{
        struct smb_softc *sc;
        struct make_dev_args mda;
        int error;

        sc = device_get_softc(dev);
        sc->sc_dev = dev;

        make_dev_args_init(&mda);
        mda.mda_devsw = &smb_cdevsw;
        mda.mda_unit = device_get_unit(dev);
        mda.mda_uid = UID_ROOT;
        mda.mda_gid = GID_WHEEL;
        mda.mda_mode = 0600;
        mda.mda_si_drv1 = sc;
        error = make_dev_s(&mda, &sc->sc_devnode, "smb%d", mda.mda_unit);
        return (error);
}

static int
smb_detach(device_t dev)
{
        struct smb_softc *sc;

        sc = device_get_softc(dev);
        destroy_dev(sc->sc_devnode);
        return (0);
}

#ifdef COMPAT_FREEBSD32
static void
smbcopyincmd32(struct smbcmd32 *uaddr, struct smbcmd *kaddr)
{
        CP(*uaddr, *kaddr, cmd);
        CP(*uaddr, *kaddr, op);
        CP(*uaddr, *kaddr, wdata.word);
        CP(*uaddr, *kaddr, slave);
        PTRIN_CP(*uaddr, *kaddr, wbuf);
        CP(*uaddr, *kaddr, wcount);
        PTRIN_CP(*uaddr, *kaddr, rbuf);
        CP(*uaddr, *kaddr, rcount);
}
#endif

static int
smbioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
{
        char buf[SMB_MAXBLOCKSIZE];
        device_t parent;
#ifdef COMPAT_FREEBSD32
        struct smbcmd sswab;
        struct smbcmd32 *s32 = (struct smbcmd32 *)data;
#endif
        struct smbcmd *s = (struct smbcmd *)data;
        struct smb_softc *sc = dev->si_drv1;
        device_t smbdev = sc->sc_dev;
        int error;
        int unit;
        u_char bcount;

        /*
         * If a specific slave device is being used, override any passed-in
         * slave.
         */
        unit = dev2unit(dev);
        if (unit & 0x0400)
                s->slave = unit & 0x03ff;

        parent = device_get_parent(smbdev);

        /* Make sure that LSB bit is cleared. */
        if (s->slave & 0x1)
                return (EINVAL);

        /* Allocate the bus. */
        if ((error = smbus_request_bus(parent, smbdev,
                        (flags & O_NONBLOCK) ? SMB_DONTWAIT : (SMB_WAIT | SMB_INTR))))
                return (error);

#ifdef COMPAT_FREEBSD32
        switch (cmd) {
        case SMB_QUICK_WRITE32:
        case SMB_QUICK_READ32:
        case SMB_SENDB32:
        case SMB_RECVB32:
        case SMB_WRITEB32:
        case SMB_WRITEW32:
        case SMB_OLD_READB32:
        case SMB_READB32:
        case SMB_OLD_READW32:
        case SMB_READW32:
        case SMB_OLD_PCALL32:
        case SMB_PCALL32:
        case SMB_BWRITE32:
        case SMB_BREAD32:
                smbcopyincmd32(s32, &sswab);
                s = &sswab;
                break;
        default:
                break;
        }
#endif

        switch (cmd) {
        case SMB_QUICK_WRITE:
#ifdef COMPAT_FREEBSD32
        case SMB_QUICK_WRITE32:
#endif
                error = smbus_error(smbus_quick(parent, s->slave, SMB_QWRITE));
                break;

        case SMB_QUICK_READ:
#ifdef COMPAT_FREEBSD32
        case SMB_QUICK_READ32:
#endif
                error = smbus_error(smbus_quick(parent, s->slave, SMB_QREAD));
                break;

        case SMB_SENDB:
#ifdef COMPAT_FREEBSD32
        case SMB_SENDB32:
#endif
                error = smbus_error(smbus_sendb(parent, s->slave, s->cmd));
                break;

        case SMB_RECVB:
#ifdef COMPAT_FREEBSD32
        case SMB_RECVB32:
#endif
                error = smbus_error(smbus_recvb(parent, s->slave, &s->cmd));
                break;

        case SMB_WRITEB:
#ifdef COMPAT_FREEBSD32
        case SMB_WRITEB32:
#endif
                error = smbus_error(smbus_writeb(parent, s->slave, s->cmd,
                                                s->wdata.byte));
                break;

        case SMB_WRITEW:
#ifdef COMPAT_FREEBSD32
        case SMB_WRITEW32:
#endif
                error = smbus_error(smbus_writew(parent, s->slave,
                                                s->cmd, s->wdata.word));
                break;

        case SMB_OLD_READB:
        case SMB_READB:
#ifdef COMPAT_FREEBSD32
        case SMB_OLD_READB32:
        case SMB_READB32:
#endif
                /* NB: for SMB_OLD_READB the read data goes to rbuf only. */
                error = smbus_error(smbus_readb(parent, s->slave, s->cmd,
                    &s->rdata.byte));
                if (error)
                        break;
                if (s->rbuf && s->rcount >= 1) {
                        error = copyout(&s->rdata.byte, s->rbuf, 1);
                        s->rcount = 1;
                }
                break;

        case SMB_OLD_READW:
        case SMB_READW:
#ifdef COMPAT_FREEBSD32
        case SMB_OLD_READW32:
        case SMB_READW32:
#endif
                /* NB: for SMB_OLD_READW the read data goes to rbuf only. */
                error = smbus_error(smbus_readw(parent, s->slave, s->cmd,
                    &s->rdata.word));
                if (error)
                        break;
                if (s->rbuf && s->rcount >= 2) {
                        buf[0] = (u_char)s->rdata.word;
                        buf[1] = (u_char)(s->rdata.word >> 8);
                        error = copyout(buf, s->rbuf, 2);
                        s->rcount = 2;
                }
                break;

        case SMB_OLD_PCALL:
        case SMB_PCALL:
#ifdef COMPAT_FREEBSD32
        case SMB_OLD_PCALL32:
        case SMB_PCALL32:
#endif
                /* NB: for SMB_OLD_PCALL the read data goes to rbuf only. */
                error = smbus_error(smbus_pcall(parent, s->slave, s->cmd,
                    s->wdata.word, &s->rdata.word));
                if (error)
                        break;
                if (s->rbuf && s->rcount >= 2) {
                        buf[0] = (u_char)s->rdata.word;
                        buf[1] = (u_char)(s->rdata.word >> 8);
                        error = copyout(buf, s->rbuf, 2);
                        s->rcount = 2;
                }

                break;

        case SMB_BWRITE:
#ifdef COMPAT_FREEBSD32
        case SMB_BWRITE32:
#endif
                if (s->wcount < 0) {
                        error = EINVAL;
                        break;
                }
                if (s->wcount > SMB_MAXBLOCKSIZE)
                        s->wcount = SMB_MAXBLOCKSIZE;
                if (s->wcount)
                        error = copyin(s->wbuf, buf, s->wcount);
                if (error)
                        break;
                error = smbus_error(smbus_bwrite(parent, s->slave, s->cmd,
                    s->wcount, buf));
                break;

        case SMB_BREAD:
#ifdef COMPAT_FREEBSD32
        case SMB_BREAD32:
#endif
                if (s->rcount < 0) {
                        error = EINVAL;
                        break;
                }
                if (s->rcount > SMB_MAXBLOCKSIZE)
                        s->rcount = SMB_MAXBLOCKSIZE;
                error = smbus_error(smbus_bread(parent, s->slave, s->cmd,
                    &bcount, buf));
                if (error)
                        break;
                if (s->rcount > bcount)
                        s->rcount = bcount;
                error = copyout(buf, s->rbuf, s->rcount);
                break;

        default:
                error = ENOTTY;
        }

#ifdef COMPAT_FREEBSD32
        switch (cmd) {
        case SMB_RECVB32:
                CP(*s, *s32, cmd);
                break;
        case SMB_OLD_READB32:
        case SMB_READB32:
        case SMB_OLD_READW32:
        case SMB_READW32:
        case SMB_OLD_PCALL32:
        case SMB_PCALL32:
                CP(*s, *s32, rdata.word);
                break;
        case SMB_BREAD32:
                if (s->rbuf == NULL)
                        CP(*s, *s32, rdata.word);
                CP(*s, *s32, rcount);
                break;
        default:
                break;
        }
#endif

        smbus_release_bus(parent, smbdev);

        return (error);
}

DRIVER_MODULE(smb, smbus, smb_driver, 0, 0);
MODULE_DEPEND(smb, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
MODULE_VERSION(smb, 1);