/*-
 * Copyright (c) 1998, 2001 Nicolas Souchu
 * 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.
 *
 * $FreeBSD: src/sys/dev/smbus/smb.c,v 1.34.8.2 2006/09/22 19:19:16 jhb Exp $
 *
 */

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

#include <bus/smbus/smbconf.h>
#include <bus/smbus/smbus.h>
#include "smb.h"

#include "smbus_if.h"

#define BUFSIZE 1024

struct smb_softc {
        device_t sc_dev;
        int sc_count;                   /* >0 if device opened */
        int sc_unit;
        cdev_t sc_devnode;
};

#define SMB_SOFTC(unit) \
        ((struct smb_softc *)devclass_get_softc(smb_devclass, (unit)))

#define SMB_DEVICE(unit) \
        (devclass_get_device(smb_devclass, (unit)))

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 devclass_t smb_devclass;

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),

#if 0
        /* bus interface */
        DEVMETHOD(bus_driver_added,     bus_generic_driver_added),
        DEVMETHOD(bus_print_child,      bus_generic_print_child),
#endif

        /* smbus interface */
        DEVMETHOD(smbus_intr,           smbus_generic_intr),

        DEVMETHOD_END
};

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

static  d_open_t        smbopen;
static  d_close_t       smbclose;
static  d_ioctl_t       smbioctl;

static struct dev_ops smb_ops = {
        { "smb", 0, 0 },
        .d_open =       smbopen,
        .d_close =      smbclose,
        .d_ioctl =      smbioctl,
};

static void
smb_identify(driver_t *driver, device_t parent)
{
        if (device_find_child(parent, "smb", -1) == NULL)
                BUS_ADD_CHILD(parent, parent, 0, "smb", -1);
}

static int
smb_probe(device_t dev)
{
        device_set_desc(dev, "SMBus generic I/O");

        /* Allow other subclasses to override this driver. */
        return (BUS_PROBE_GENERIC);
}

static int
smb_attach(device_t dev)
{
        struct smb_softc *sc = (struct smb_softc *)device_get_softc(dev);
        int unit;

        if (!sc)
                return (ENOMEM);

        bzero(sc, sizeof(struct smb_softc *));
        unit = device_get_unit(dev);
        sc->sc_dev = dev;
        sc->sc_unit = unit;

        if (unit & 0x0400) {
                sc->sc_devnode = make_dev(&smb_ops, unit,
                                UID_ROOT, GID_WHEEL, 0600,
                                "smb%d-%02x", unit >> 11, unit & 1023);
        } else {
                sc->sc_devnode = make_dev(&smb_ops, unit,
                                UID_ROOT, GID_WHEEL, 0600, "smb%d", unit);
        }

        return (0);
}

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

        if (sc->sc_devnode)
                dev_ops_remove_minor(&smb_ops, device_get_unit(dev));

        return (0);
}

static int
smbopen (struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct smb_softc *sc = SMB_SOFTC(minor(dev));

        if (sc == NULL)
                return (ENXIO);

        if (sc->sc_count != 0)
                return (EBUSY);

        sc->sc_count++;

        return (0);
}

static int
smbclose(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct smb_softc *sc = SMB_SOFTC(minor(dev));

        if (sc == NULL)
                return (ENXIO);

        if (sc->sc_count == 0)
                /* This is not supposed to happen. */
                return (0);

        sc->sc_count--;

        return (0);
}

#if 0
static int
smbwrite(struct dev_write_args *ap)
{
        return (EINVAL);
}

static int
smbread(struct dev_read_args *ap)
{
        return (EINVAL);
}
#endif

static int
smbioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        device_t bus;           /* smbbus */
        char buf[SMB_MAXBLOCKSIZE];
        struct smbcmd *s = (struct smbcmd *)ap->a_data;
        struct smb_softc *sc = SMB_SOFTC(minor(dev));
        device_t smbdev = SMB_DEVICE(minor(dev));
        int error;
        int unit;
        u_char bcount;

        if (sc == NULL)
                return (ENXIO);
        if (s == NULL)
                return (EINVAL);

        /*
         * If a specific slave device is being used, override any passed-in
         * slave.
         */
        unit = sc->sc_unit;
        if (unit & 0x0400) {
                s->slave = unit & 1023;
        }

        /*
         * NOTE: smbus_*() functions automatically recurse the parent to
         *       get to the actual device driver.
         */
        bus = device_get_parent(smbdev);        /* smbus */

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

        switch (ap->a_cmd) {
        case SMB_QUICK_WRITE:
                error = smbus_error(smbus_quick(bus, s->slave, SMB_QWRITE));
                break;

        case SMB_QUICK_READ:
                error = smbus_error(smbus_quick(bus, s->slave, SMB_QREAD));
                break;

        case SMB_SENDB:
                error = smbus_error(smbus_sendb(bus, s->slave, s->cmd));
                break;

        case SMB_RECVB:
                error = smbus_error(smbus_recvb(bus, s->slave, &s->cmd));
                break;

        case SMB_WRITEB:
                error = smbus_error(smbus_writeb(bus, s->slave, s->cmd,
                                                s->wdata.byte));
                break;

        case SMB_WRITEW:
                error = smbus_error(smbus_writew(bus, s->slave, s->cmd,
                                                s->wdata.word));
                break;

        case SMB_READB:
                error = smbus_error(smbus_readb(bus, s->slave, s->cmd,
                                                &s->rdata.byte));
                if (s->rbuf && s->rcount >= 1) {
                        error = copyout(&s->rdata.byte, s->rbuf, 1);
                        s->rcount = 1;
                }
                break;

        case SMB_READW:
                error = smbus_error(smbus_readw(bus, s->slave, s->cmd,
                                                &s->rdata.word));
                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_PCALL:
                error = smbus_error(smbus_pcall(bus, s->slave, s->cmd,
                                                s->wdata.word, &s->rdata.word));
                if (s->rbuf && s->rcount >= 2) {
                        char buf[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:
                if (s->wcount < 0)
                        s->wcount = 0;
                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(bus, s->slave, s->cmd,
                                                 s->wcount, buf));
                break;

        case SMB_BREAD:
                if (s->rcount < 0)
                        s->rcount = 0;
                if (s->rcount > SMB_MAXBLOCKSIZE)
                        s->rcount = SMB_MAXBLOCKSIZE;
                error = smbus_bread(bus, s->slave, s->cmd, &bcount, buf);
                error = smbus_error(error);
                if (error)
                        break;
                if (s->rcount > bcount)
                        s->rcount = bcount;
                error = copyout(buf, s->rbuf, s->rcount);
                break;

        case SMB_TRANS:
                if (s->rcount < 0)
                        s->rcount = 0;
                if (s->rcount > SMB_MAXBLOCKSIZE)
                        s->rcount = SMB_MAXBLOCKSIZE;
                if (s->wcount < 0)
                        s->wcount = 0;
                if (s->wcount > SMB_MAXBLOCKSIZE)
                        s->wcount = SMB_MAXBLOCKSIZE;
                if (s->wcount)
                        error = copyin(s->wbuf, buf, s->wcount);
                if (error)
                        break;
                error = smbus_trans(bus, s->slave, s->cmd, s->op,
                                    buf, s->wcount, buf, s->rcount, &s->rcount);
                error = smbus_error(error);
                if (error == 0)
                        error = copyout(buf, s->rbuf, s->rcount);
                break;
        default:
                error = ENOTTY;
                break;
        }

        smbus_release_bus(bus, smbdev);

        return (error);
}

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