/*-
 * Copyright (c) 1998 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/iicbus/if_ic.c,v 1.8 1999/12/29 04:35:39 peter Exp $
 */

/*
 * I2C bus IP driver
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/filio.h>
#include <sys/sockio.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/time.h>
#include <sys/malloc.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/ifq_var.h>
#include <net/if_types.h>
#include <net/netisr.h>

#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>

#include <net/bpf.h>

#include <bus/iicbus/iiconf.h>
#include <bus/iicbus/iicbus.h>

#include "iicbus_if.h"

#define PCF_MASTER_ADDRESS 0xaa

#define ICHDRLEN        sizeof(uint32_t)
#define ICMTU           1500            /* default mtu */

struct ic_softc {
        struct ifnet ic_if;

        u_char ic_addr;                 /* peer I2C address */

        int ic_sending;

        char *ic_obuf;
        char *ic_ifbuf;
        char *ic_cp;

        int ic_xfercnt;

        int ic_iferrs;
};

static devclass_t ic_devclass;

static int icprobe(device_t);
static int icattach(device_t);

static int icioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
static int icoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
                struct rtentry *);

static void icintr(device_t, int, char *);

static device_method_t ic_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         icprobe),
        DEVMETHOD(device_attach,        icattach),

        /* iicbus interface */
        DEVMETHOD(iicbus_intr,          icintr),

        DEVMETHOD_END
};

static driver_t ic_driver = {
        "ic",
        ic_methods,
        sizeof(struct ic_softc),
};

/*
 * icprobe()
 */
static int
icprobe(device_t dev)
{
        return (0);
}
        
/*
 * icattach()
 */
static int
icattach(device_t dev)
{
        struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
        struct ifnet *ifp = &sc->ic_if;

        sc->ic_addr = PCF_MASTER_ADDRESS;       /* XXX only PCF masters */

        ifp->if_softc = sc;
        if_initname(ifp, "ic", device_get_unit(dev));
        ifp->if_mtu = ICMTU;
        ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
        ifp->if_ioctl = icioctl;
        ifp->if_output = icoutput;
        ifp->if_type = IFT_PARA;
        ifp->if_hdrlen = 0;
        ifp->if_addrlen = 0;
        ifq_set_maxlen(&ifp->if_snd, IFQ_MAXLEN);

        if_attach(ifp, NULL);

        bpfattach(ifp, DLT_NULL, ICHDRLEN);

        return (0);
}

/*
 * iciotcl()
 */
static int
icioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
{
    device_t icdev = devclass_get_device(ic_devclass, ifp->if_dunit);
    device_t parent = device_get_parent(icdev);
    struct ic_softc *sc = (struct ic_softc *)device_get_softc(icdev);

    struct ifaddr *ifa = (struct ifaddr *)data;
    struct ifreq *ifr = (struct ifreq *)data;

    u_char *iptr, *optr;
    int error;

    switch (cmd) {

    case SIOCSIFDSTADDR:
    case SIOCAIFADDR:
    case SIOCSIFADDR:
        if (ifa->ifa_addr->sa_family != AF_INET)
            return EAFNOSUPPORT;
        ifp->if_flags |= IFF_UP;
        /* FALLTHROUGH */
    case SIOCSIFFLAGS:
        if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {

            /* XXX disable PCF */
            ifp->if_flags &= ~IFF_RUNNING;

            /* IFF_UP is not set, try to release the bus anyway */
            iicbus_release_bus(parent, icdev);
            break;
        }
        if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {

            if ((error = iicbus_request_bus(parent, icdev, IIC_WAIT|IIC_INTR)))
                return (error);

            sc->ic_obuf = kmalloc(sc->ic_if.if_mtu + ICHDRLEN,
                                  M_DEVBUF, M_WAITOK);

            sc->ic_ifbuf = kmalloc(sc->ic_if.if_mtu + ICHDRLEN,
                                  M_DEVBUF, M_WAITOK);

            iicbus_reset(parent, IIC_FASTEST, 0, NULL);

            ifp->if_flags |= IFF_RUNNING;
        }
        break;

    case SIOCSIFMTU:
        /* save previous buffers */
        iptr = sc->ic_ifbuf;
        optr = sc->ic_obuf;

        /* allocate input buffer */
        sc->ic_ifbuf = kmalloc(ifr->ifr_mtu+ICHDRLEN, M_DEVBUF, M_WAITOK);

        /* allocate output buffer */
        sc->ic_obuf = kmalloc(ifr->ifr_mtu+ICHDRLEN, M_DEVBUF, M_WAITOK);

        if (iptr)
            kfree(iptr,M_DEVBUF);

        if (optr)
            kfree(optr,M_DEVBUF);

        sc->ic_if.if_mtu = ifr->ifr_mtu;
        break;

    case SIOCGIFMTU:
        ifr->ifr_mtu = sc->ic_if.if_mtu;
        break;

    case SIOCADDMULTI:
    case SIOCDELMULTI:
        if (ifr == NULL) {
            return EAFNOSUPPORT;                /* XXX */
        }
        switch (ifr->ifr_addr.sa_family) {

        case AF_INET:
            break;

        default:
            return EAFNOSUPPORT;
        }
        break;

    default:
        return EINVAL;
    }
    return 0;
}

/*
 * icintr()
 */
static void
icintr (device_t dev, int event, char *ptr)
{
        struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
        int unit = device_get_unit(dev);
        int len;
        struct mbuf *top;
        
        crit_enter();

        switch (event) {

        case INTR_GENERAL:
        case INTR_START:
                sc->ic_cp = sc->ic_ifbuf;
                sc->ic_xfercnt = 0;
                break;

        case INTR_STOP:

          /* if any error occured during transfert,
           * drop the packet */
          if (sc->ic_iferrs)
            goto err;

          if ((len = sc->ic_xfercnt) == 0)
                break;                                  /* ignore */

          if (len <= ICHDRLEN)
            goto err;

          len -= ICHDRLEN;
          IFNET_STAT_INC(&sc->ic_if, ipackets, 1);
          IFNET_STAT_INC(&sc->ic_if, ibytes, len);

          BPF_TAP(&sc->ic_if, sc->ic_ifbuf, len + ICHDRLEN);

          top = m_devget(sc->ic_ifbuf + ICHDRLEN, len, 0, &sc->ic_if);

          if (top)
            netisr_queue(NETISR_IP, top);
          break;

        err:
          kprintf("ic%d: errors (%d)!\n", unit, sc->ic_iferrs);

          sc->ic_iferrs = 0;                    /* reset error count */
          IFNET_STAT_INC(&sc->ic_if, ierrors, 1);

          break;

        case INTR_RECEIVE:
                if (sc->ic_xfercnt >= sc->ic_if.if_mtu+ICHDRLEN) {
                        sc->ic_iferrs ++;

                } else {
                        *sc->ic_cp++ = *ptr;
                        sc->ic_xfercnt ++;
                }
                break;

        case INTR_NOACK:                        /* xfer terminated by master */
                break;

        case INTR_TRANSMIT:
                *ptr = 0xff;                                    /* XXX */
                break;

        case INTR_ERROR:
                sc->ic_iferrs ++;
                break;

        default:
                panic("%s: unknown event (%d)!", __func__, event);
        }

        crit_exit();
}

/*
 * icoutput()
 */
static int
icoutput(struct ifnet *ifp, struct mbuf *m,
        struct sockaddr *dst, struct rtentry *rt)
{
        device_t icdev = devclass_get_device(ic_devclass, ifp->if_dunit);
        device_t parent = device_get_parent(icdev);
        struct ic_softc *sc = (struct ic_softc *)device_get_softc(icdev);
        int len, sent;
        struct mbuf *mm;
        u_char *cp;
        uint32_t hdr = dst->sa_family;

        ifp->if_flags |= IFF_RUNNING;

        crit_enter();

        /* already sending? */
        if (sc->ic_sending) {
                IFNET_STAT_INC(ifp, oerrors, 1);
                goto error;
        }
                
        /* insert header */
        bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);

        cp = sc->ic_obuf + ICHDRLEN;
        len = 0;
        mm = m;
        do {
                if (len + mm->m_len > sc->ic_if.if_mtu) {
                        /* packet to large */
                        IFNET_STAT_INC(ifp, oerrors, 1);
                        goto error;
                }
                        
                bcopy(mtod(mm,char *), cp, mm->m_len);
                cp += mm->m_len;
                len += mm->m_len;

        } while ((mm = mm->m_next));

        if (ifp->if_bpf) {
                bpf_gettoken();
                if (ifp->if_bpf)
                        bpf_ptap(ifp->if_bpf, m, &hdr, ICHDRLEN);
                bpf_reltoken();
        }

        sc->ic_sending = 1;

        m_freem(m);

        crit_exit();

        /* send the packet */
        if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
                                len + ICHDRLEN, &sent))

                IFNET_STAT_INC(ifp, oerrors, 1);
        else {
                IFNET_STAT_INC(ifp, opackets, 1);
                IFNET_STAT_INC(ifp, obytes, len);
        }

        sc->ic_sending = 0;

        return (0);

error:
        m_freem(m);
        crit_exit();

        return(0);
}

DRIVER_MODULE(if_ic, iicbus, ic_driver, ic_devclass, NULL, NULL);
MODULE_DEPEND(if_ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_VERSION(if_ic, 1);