GUI: Fix Tomato RAF theme for all builds. Compilation typo.

[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / drivers / net / wan / cycx_x25.c

/*
* cycx_x25.c    Cyclom 2X WAN Link Driver.  X.25 module.
*
* Author:       Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* Copyright:    (c) 1998-2003 Arnaldo Carvalho de Melo
*
* Based on sdla_x25.c by Gene Kozin <genek@compuserve.com>
*
*               This program is free software; you can redistribute it and/or
*               modify it under the terms of the GNU General Public License
*               as published by the Free Software Foundation; either version
*               2 of the License, or (at your option) any later version.
* ============================================================================
* 2001/01/12    acme            use dev_kfree_skb_irq on interrupt context
* 2000/04/02    acme            dprintk, cycx_debug
*                               fixed the bug introduced in get_dev_by_lcn and
*                               get_dev_by_dte_addr by the anonymous hacker
*                               that converted this driver to softnet
* 2000/01/08    acme            cleanup
* 1999/10/27    acme            use ARPHRD_HWX25 so that the X.25 stack know
*                               that we have a X.25 stack implemented in
*                               firmware onboard
* 1999/10/18    acme            support for X.25 sockets in if_send,
*                               beware: socket(AF_X25...) IS WORK IN PROGRESS,
*                               TCP/IP over X.25 via wanrouter not affected,
*                               working.
* 1999/10/09    acme            chan_disc renamed to chan_disconnect,
*                               began adding support for X.25 sockets:
*                               conf->protocol in new_if
* 1999/10/05    acme            fixed return E... to return -E...
* 1999/08/10    acme            serialized access to the card thru a spinlock
*                               in x25_exec
* 1999/08/09    acme            removed per channel spinlocks
*                               removed references to enable_tx_int
* 1999/05/28    acme            fixed nibble_to_byte, ackvc now properly treated
*                               if_send simplified
* 1999/05/25    acme            fixed t1, t2, t21 & t23 configuration
*                               use spinlocks instead of cli/sti in some points
* 1999/05/24    acme            finished the x25_get_stat function
* 1999/05/23    acme            dev->type = ARPHRD_X25 (tcpdump only works,
*                               AFAIT, with ARPHRD_ETHER). This seems to be
*                               needed to use socket(AF_X25)...
*                               Now the config file must specify a peer media
*                               address for svc channels over a crossover cable.
*                               Removed hold_timeout from x25_channel_t,
*                               not used.
*                               A little enhancement in the DEBUG processing
* 1999/05/22    acme            go to DISCONNECTED in disconnect_confirm_intr,
*                               instead of chan_disc.
* 1999/05/16    marcelo         fixed timer initialization in SVCs
* 1999/01/05    acme            x25_configure now get (most of) all
*                               parameters...
* 1999/01/05    acme            pktlen now (correctly) uses log2 (value
*                               configured)
* 1999/01/03    acme            judicious use of data types (u8, u16, u32, etc)
* 1999/01/03    acme            cyx_isr: reset dpmbase to acknowledge
*                               indication (interrupt from cyclom 2x)
* 1999/01/02    acme            cyx_isr: first hackings...
* 1999/01/0203  acme            when initializing an array don't give less
*                               elements than declared...
*                               example: char send_cmd[6] = "?\xFF\x10";
*                               you'll gonna lose a couple hours, 'cause your
*                               brain won't admit that there's an error in the
*                               above declaration...  the side effect is that
*                               memset is put into the unresolved symbols
*                               instead of using the inline memset functions...
* 1999/01/02    acme            began chan_connect, chan_send, x25_send
* 1998/12/31    acme            x25_configure
*                               this code can be compiled as non module
* 1998/12/27    acme            code cleanup
*                               IPX code wiped out! let's decrease code
*                               complexity for now, remember: I'm learning! :)
*                               bps_to_speed_code OK
* 1998/12/26    acme            Minimal debug code cleanup
* 1998/08/08    acme            Initial version.
*/

#define CYCLOMX_X25_DEBUG 1

#include <linux/ctype.h>        /* isdigit() */
#include <linux/errno.h>        /* return codes */
#include <linux/if_arp.h>       /* ARPHRD_HWX25 */
#include <linux/kernel.h>       /* printk(), and other useful stuff */
#include <linux/module.h>
#include <linux/string.h>       /* inline memset(), etc. */
#include <linux/sched.h>
#include <linux/slab.h>         /* kmalloc(), kfree() */
#include <linux/stddef.h>       /* offsetof(), etc. */
#include <linux/wanrouter.h>    /* WAN router definitions */

#include <asm/byteorder.h>      /* htons(), etc. */

#include <linux/cyclomx.h>      /* Cyclom 2X common user API definitions */
#include <linux/cycx_x25.h>     /* X.25 firmware API definitions */

#include <net/x25device.h>

/* Defines & Macros */
#define CYCX_X25_MAX_CMD_RETRY 5
#define CYCX_X25_CHAN_MTU 2048  /* unfragmented logical channel MTU */

/* Data Structures */
/* This is an extension of the 'struct net_device' we create for each network
   interface to keep the rest of X.25 channel-specific data. */
struct cycx_x25_channel {
        /* This member must be first. */
        struct net_device *slave;       /* WAN slave */

        char name[WAN_IFNAME_SZ+1];     /* interface name, ASCIIZ */
        char addr[WAN_ADDRESS_SZ+1];    /* media address, ASCIIZ */
        char *local_addr;               /* local media address, ASCIIZ -
                                           svc thru crossover cable */
        s16 lcn;                        /* logical channel number/conn.req.key*/
        u8 link;
        struct timer_list timer;        /* timer used for svc channel disc. */
        u16 protocol;                   /* ethertype, 0 - multiplexed */
        u8 svc;                         /* 0 - permanent, 1 - switched */
        u8 state;                       /* channel state */
        u8 drop_sequence;               /* mark sequence for dropping */
        u32 idle_tmout;                 /* sec, before disconnecting */
        struct sk_buff *rx_skb;         /* receive socket buffer */
        struct cycx_device *card;       /* -> owner */
        struct net_device_stats ifstats;/* interface statistics */
};

/* Function Prototypes */
/* WAN link driver entry points. These are called by the WAN router module. */
static int cycx_wan_update(struct wan_device *wandev),
           cycx_wan_new_if(struct wan_device *wandev, struct net_device *dev,
                           wanif_conf_t *conf),
           cycx_wan_del_if(struct wan_device *wandev, struct net_device *dev);

/* Network device interface */
static int cycx_netdevice_init(struct net_device *dev);
static int cycx_netdevice_open(struct net_device *dev);
static int cycx_netdevice_stop(struct net_device *dev);
static int cycx_netdevice_hard_header(struct sk_buff *skb,
                                      struct net_device *dev, u16 type,
                                      const void *daddr, const void *saddr,
                                      unsigned len);
static int cycx_netdevice_rebuild_header(struct sk_buff *skb);
static netdev_tx_t cycx_netdevice_hard_start_xmit(struct sk_buff *skb,
                                                        struct net_device *dev);

static struct net_device_stats *
                        cycx_netdevice_get_stats(struct net_device *dev);

/* Interrupt handlers */
static void cycx_x25_irq_handler(struct cycx_device *card),
            cycx_x25_irq_tx(struct cycx_device *card, struct cycx_x25_cmd *cmd),
            cycx_x25_irq_rx(struct cycx_device *card, struct cycx_x25_cmd *cmd),
            cycx_x25_irq_log(struct cycx_device *card,
                             struct cycx_x25_cmd *cmd),
            cycx_x25_irq_stat(struct cycx_device *card,
                              struct cycx_x25_cmd *cmd),
            cycx_x25_irq_connect_confirm(struct cycx_device *card,
                                         struct cycx_x25_cmd *cmd),
            cycx_x25_irq_disconnect_confirm(struct cycx_device *card,
                                            struct cycx_x25_cmd *cmd),
            cycx_x25_irq_connect(struct cycx_device *card,
                                 struct cycx_x25_cmd *cmd),
            cycx_x25_irq_disconnect(struct cycx_device *card,
                                    struct cycx_x25_cmd *cmd),
            cycx_x25_irq_spurious(struct cycx_device *card,
                                  struct cycx_x25_cmd *cmd);

/* X.25 firmware interface functions */
static int cycx_x25_configure(struct cycx_device *card,
                              struct cycx_x25_config *conf),
           cycx_x25_get_stats(struct cycx_device *card),
           cycx_x25_send(struct cycx_device *card, u8 link, u8 lcn, u8 bitm,
                         int len, void *buf),
           cycx_x25_connect_response(struct cycx_device *card,
                                struct cycx_x25_channel *chan),
           cycx_x25_disconnect_response(struct cycx_device *card, u8 link,
                                        u8 lcn);

/* channel functions */
static int cycx_x25_chan_connect(struct net_device *dev),
           cycx_x25_chan_send(struct net_device *dev, struct sk_buff *skb);

static void cycx_x25_chan_disconnect(struct net_device *dev),
            cycx_x25_chan_send_event(struct net_device *dev, u8 event);

/* Miscellaneous functions */
static void cycx_x25_set_chan_state(struct net_device *dev, u8 state),
            cycx_x25_chan_timer(unsigned long d);

static void nibble_to_byte(u8 *s, u8 *d, u8 len, u8 nibble),
            reset_timer(struct net_device *dev);

static u8 bps_to_speed_code(u32 bps);
static u8 cycx_log2(u32 n);

static unsigned dec_to_uint(u8 *str, int len);

static struct net_device *cycx_x25_get_dev_by_lcn(struct wan_device *wandev,
                                                  s16 lcn);
static struct net_device *
        cycx_x25_get_dev_by_dte_addr(struct wan_device *wandev, char *dte);

static void cycx_x25_chan_setup(struct net_device *dev);

#ifdef CYCLOMX_X25_DEBUG
static void hex_dump(char *msg, unsigned char *p, int len);
static void cycx_x25_dump_config(struct cycx_x25_config *conf);
static void cycx_x25_dump_stats(struct cycx_x25_stats *stats);
static void cycx_x25_dump_devs(struct wan_device *wandev);
#else
#define hex_dump(msg, p, len)
#define cycx_x25_dump_config(conf)
#define cycx_x25_dump_stats(stats)
#define cycx_x25_dump_devs(wandev)
#endif
/* Public Functions */

/* X.25 Protocol Initialization routine.
 *
 * This routine is called by the main Cyclom 2X module during setup.  At this
 * point adapter is completely initialized and X.25 firmware is running.
 *  o configure adapter
 *  o initialize protocol-specific fields of the adapter data space.
 *
 * Return:      0       o.k.
 *              < 0     failure.  */
int cycx_x25_wan_init(struct cycx_device *card, wandev_conf_t *conf)
{
        struct cycx_x25_config cfg;

        /* Verify configuration ID */
        if (conf->config_id != WANCONFIG_X25) {
                printk(KERN_INFO "%s: invalid configuration ID %u!\n",
                                 card->devname, conf->config_id);
                return -EINVAL;
        }

        /* Initialize protocol-specific fields */
        card->mbox  = card->hw.dpmbase + X25_MBOX_OFFS;
        card->u.x.connection_keys = 0;
        spin_lock_init(&card->u.x.lock);

        /* Configure adapter. Here we set reasonable defaults, then parse
         * device configuration structure and set configuration options.
         * Most configuration options are verified and corrected (if
         * necessary) since we can't rely on the adapter to do so and don't
         * want it to fail either. */
        memset(&cfg, 0, sizeof(cfg));
        cfg.link = 0;
        cfg.clock = conf->clocking == WANOPT_EXTERNAL ? 8 : 55;
        cfg.speed = bps_to_speed_code(conf->bps);
        cfg.n3win = 7;
        cfg.n2win = 2;
        cfg.n2 = 5;
        cfg.nvc = 1;
        cfg.npvc = 1;
        cfg.flags = 0x02; /* default = V35 */
        cfg.t1 = 10;   /* line carrier timeout */
        cfg.t2 = 29;   /* tx timeout */
        cfg.t21 = 180; /* CALL timeout */
        cfg.t23 = 180; /* CLEAR timeout */

        /* adjust MTU */
        if (!conf->mtu || conf->mtu >= 512)
                card->wandev.mtu = 512;
        else if (conf->mtu >= 256)
                card->wandev.mtu = 256;
        else if (conf->mtu >= 128)
                card->wandev.mtu = 128;
        else
                card->wandev.mtu = 64;

        cfg.pktlen = cycx_log2(card->wandev.mtu);

        if (conf->station == WANOPT_DTE) {
                cfg.locaddr = 3; /* DTE */
                cfg.remaddr = 1; /* DCE */
        } else {
                cfg.locaddr = 1; /* DCE */
                cfg.remaddr = 3; /* DTE */
        }

        if (conf->interface == WANOPT_RS232)
                cfg.flags = 0;

        if (conf->u.x25.hi_pvc) {
                card->u.x.hi_pvc = min_t(unsigned int, conf->u.x25.hi_pvc, 4095);
                card->u.x.lo_pvc = min_t(unsigned int, conf->u.x25.lo_pvc, card->u.x.hi_pvc);
        }

        if (conf->u.x25.hi_svc) {
                card->u.x.hi_svc = min_t(unsigned int, conf->u.x25.hi_svc, 4095);
                card->u.x.lo_svc = min_t(unsigned int, conf->u.x25.lo_svc, card->u.x.hi_svc);
        }

        if (card->u.x.lo_pvc == 255)
                cfg.npvc = 0;
        else
                cfg.npvc = card->u.x.hi_pvc - card->u.x.lo_pvc + 1;

        cfg.nvc = card->u.x.hi_svc - card->u.x.lo_svc + 1 + cfg.npvc;

        if (conf->u.x25.hdlc_window)
                cfg.n2win = min_t(unsigned int, conf->u.x25.hdlc_window, 7);

        if (conf->u.x25.pkt_window)
                cfg.n3win = min_t(unsigned int, conf->u.x25.pkt_window, 7);

        if (conf->u.x25.t1)
                cfg.t1 = min_t(unsigned int, conf->u.x25.t1, 30);

        if (conf->u.x25.t2)
                cfg.t2 = min_t(unsigned int, conf->u.x25.t2, 30);

        if (conf->u.x25.t11_t21)
                cfg.t21 = min_t(unsigned int, conf->u.x25.t11_t21, 30);

        if (conf->u.x25.t13_t23)
                cfg.t23 = min_t(unsigned int, conf->u.x25.t13_t23, 30);

        if (conf->u.x25.n2)
                cfg.n2 = min_t(unsigned int, conf->u.x25.n2, 30);

        /* initialize adapter */
        if (cycx_x25_configure(card, &cfg))
                return -EIO;

        /* Initialize protocol-specific fields of adapter data space */
        card->wandev.bps        = conf->bps;
        card->wandev.interface  = conf->interface;
        card->wandev.clocking   = conf->clocking;
        card->wandev.station    = conf->station;
        card->isr               = cycx_x25_irq_handler;
        card->exec              = NULL;
        card->wandev.update     = cycx_wan_update;
        card->wandev.new_if     = cycx_wan_new_if;
        card->wandev.del_if     = cycx_wan_del_if;
        card->wandev.state      = WAN_DISCONNECTED;

        return 0;
}

/* WAN Device Driver Entry Points */
/* Update device status & statistics. */
static int cycx_wan_update(struct wan_device *wandev)
{
        /* sanity checks */
        if (!wandev || !wandev->private)
                return -EFAULT;

        if (wandev->state == WAN_UNCONFIGURED)
                return -ENODEV;

        cycx_x25_get_stats(wandev->private);

        return 0;
}

/* Create new logical channel.
 * This routine is called by the router when ROUTER_IFNEW IOCTL is being
 * handled.
 * o parse media- and hardware-specific configuration
 * o make sure that a new channel can be created
 * o allocate resources, if necessary
 * o prepare network device structure for registration.
 *
 * Return:      0       o.k.
 *              < 0     failure (channel will not be created) */
static int cycx_wan_new_if(struct wan_device *wandev, struct net_device *dev,
                           wanif_conf_t *conf)
{
        struct cycx_device *card = wandev->private;
        struct cycx_x25_channel *chan;
        int err = 0;

        if (!conf->name[0] || strlen(conf->name) > WAN_IFNAME_SZ) {
                printk(KERN_INFO "%s: invalid interface name!\n",
                       card->devname);
                return -EINVAL;
        }

        dev = alloc_netdev(sizeof(struct cycx_x25_channel), conf->name,
                             cycx_x25_chan_setup);
        if (!dev)
                return -ENOMEM;

        chan = netdev_priv(dev);
        strcpy(chan->name, conf->name);
        chan->card = card;
        chan->link = conf->port;
        chan->protocol = conf->protocol ? ETH_P_X25 : ETH_P_IP;
        chan->rx_skb = NULL;
        /* only used in svc connected thru crossover cable */
        chan->local_addr = NULL;

        if (conf->addr[0] == '@') {     /* SVC */
                int len = strlen(conf->local_addr);

                if (len) {
                        if (len > WAN_ADDRESS_SZ) {
                                printk(KERN_ERR "%s: %s local addr too long!\n",
                                                wandev->name, chan->name);
                                err = -EINVAL;
                                goto error;
                        } else {
                                chan->local_addr = kmalloc(len + 1, GFP_KERNEL);

                                if (!chan->local_addr) {
                                        err = -ENOMEM;
                                        goto error;
                                }
                        }

                        strncpy(chan->local_addr, conf->local_addr,
                                WAN_ADDRESS_SZ);
                }

                chan->svc = 1;
                strncpy(chan->addr, &conf->addr[1], WAN_ADDRESS_SZ);
                init_timer(&chan->timer);
                chan->timer.function    = cycx_x25_chan_timer;
                chan->timer.data        = (unsigned long)dev;

                /* Set channel timeouts (default if not specified) */
                chan->idle_tmout = conf->idle_timeout ? conf->idle_timeout : 90;
        } else if (isdigit(conf->addr[0])) {    /* PVC */
                s16 lcn = dec_to_uint(conf->addr, 0);

                if (lcn >= card->u.x.lo_pvc && lcn <= card->u.x.hi_pvc)
                        chan->lcn = lcn;
                else {
                        printk(KERN_ERR
                                "%s: PVC %u is out of range on interface %s!\n",
                                wandev->name, lcn, chan->name);
                        err = -EINVAL;
                        goto error;
                }
        } else {
                printk(KERN_ERR "%s: invalid media address on interface %s!\n",
                                wandev->name, chan->name);
                err = -EINVAL;
                goto error;
        }

        return 0;

error:
        free_netdev(dev);
        return err;
}

/* Delete logical channel. */
static int cycx_wan_del_if(struct wan_device *wandev, struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);

        if (chan->svc) {
                kfree(chan->local_addr);
                if (chan->state == WAN_CONNECTED)
                        del_timer(&chan->timer);
        }

        return 0;
}


/* Network Device Interface */

static const struct header_ops cycx_header_ops = {
        .create = cycx_netdevice_hard_header,
        .rebuild = cycx_netdevice_rebuild_header,
};

static const struct net_device_ops cycx_netdev_ops = {
        .ndo_init       = cycx_netdevice_init,
        .ndo_open       = cycx_netdevice_open,
        .ndo_stop       = cycx_netdevice_stop,
        .ndo_start_xmit = cycx_netdevice_hard_start_xmit,
        .ndo_get_stats  = cycx_netdevice_get_stats,
};

static void cycx_x25_chan_setup(struct net_device *dev)
{
        /* Initialize device driver entry points */
        dev->netdev_ops         = &cycx_netdev_ops;
        dev->header_ops         = &cycx_header_ops;

        /* Initialize media-specific parameters */
        dev->mtu                = CYCX_X25_CHAN_MTU;
        dev->type               = ARPHRD_HWX25; /* ARP h/w type */
        dev->hard_header_len    = 0;            /* media header length */
        dev->addr_len           = 0;            /* hardware address length */
}

/* Initialize Linux network interface.
 *
 * This routine is called only once for each interface, during Linux network
 * interface registration.  Returning anything but zero will fail interface
 * registration. */
static int cycx_netdevice_init(struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);
        struct cycx_device *card = chan->card;
        struct wan_device *wandev = &card->wandev;

        if (!chan->svc)
                *(__be16*)dev->dev_addr = htons(chan->lcn);

        /* Initialize hardware parameters (just for reference) */
        dev->irq                = wandev->irq;
        dev->dma                = wandev->dma;
        dev->base_addr          = wandev->ioport;
        dev->mem_start          = (unsigned long)wandev->maddr;
        dev->mem_end            = (unsigned long)(wandev->maddr +
                                                  wandev->msize - 1);
        dev->flags              |= IFF_NOARP;

        /* Set transmit buffer queue length */
        dev->tx_queue_len       = 10;

        /* Initialize socket buffers */
        cycx_x25_set_chan_state(dev, WAN_DISCONNECTED);

        return 0;
}

/* Open network interface.
 * o prevent module from unloading by incrementing use count
 * o if link is disconnected then initiate connection
 *
 * Return 0 if O.k. or errno.  */
static int cycx_netdevice_open(struct net_device *dev)
{
        if (netif_running(dev))
                return -EBUSY; /* only one open is allowed */

        netif_start_queue(dev);
        return 0;
}

/* Close network interface.
 * o reset flags.
 * o if there's no more open channels then disconnect physical link. */
static int cycx_netdevice_stop(struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);

        netif_stop_queue(dev);

        if (chan->state == WAN_CONNECTED || chan->state == WAN_CONNECTING)
                cycx_x25_chan_disconnect(dev);

        return 0;
}

/* Build media header.
 * o encapsulate packet according to encapsulation type.
 *
 * The trick here is to put packet type (Ethertype) into 'protocol' field of
 * the socket buffer, so that we don't forget it.  If encapsulation fails,
 * set skb->protocol to 0 and discard packet later.
 *
 * Return:      media header length. */
static int cycx_netdevice_hard_header(struct sk_buff *skb,
                                      struct net_device *dev, u16 type,
                                      const void *daddr, const void *saddr,
                                      unsigned len)
{
        skb->protocol = htons(type);

        return dev->hard_header_len;
}

/* * Re-build media header.
 * Return:      1       physical address resolved.
 *              0       physical address not resolved */
static int cycx_netdevice_rebuild_header(struct sk_buff *skb)
{
        return 1;
}

/* Send a packet on a network interface.
 * o set busy flag (marks start of the transmission).
 * o check link state. If link is not up, then drop the packet.
 * o check channel status. If it's down then initiate a call.
 * o pass a packet to corresponding WAN device.
 * o free socket buffer
 *
 * Return:      0       complete (socket buffer must be freed)
 *              non-0   packet may be re-transmitted (tbusy must be set)
 *
 * Notes:
 * 1. This routine is called either by the protocol stack or by the "net
 *    bottom half" (with interrupts enabled).
 * 2. Setting tbusy flag will inhibit further transmit requests from the
 *    protocol stack and can be used for flow control with protocol layer. */
static netdev_tx_t cycx_netdevice_hard_start_xmit(struct sk_buff *skb,
                                                        struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);
        struct cycx_device *card = chan->card;

        if (!chan->svc)
                chan->protocol = ntohs(skb->protocol);

        if (card->wandev.state != WAN_CONNECTED)
                ++chan->ifstats.tx_dropped;
        else if (chan->svc && chan->protocol &&
                 chan->protocol != ntohs(skb->protocol)) {
                printk(KERN_INFO
                       "%s: unsupported Ethertype 0x%04X on interface %s!\n",
                       card->devname, ntohs(skb->protocol), dev->name);
                ++chan->ifstats.tx_errors;
        } else if (chan->protocol == ETH_P_IP) {
                switch (chan->state) {
                case WAN_DISCONNECTED:
                        if (cycx_x25_chan_connect(dev)) {
                                netif_stop_queue(dev);
                                return NETDEV_TX_BUSY;
                        }
                        /* fall thru */
                case WAN_CONNECTED:
                        reset_timer(dev);
                        dev->trans_start = jiffies;
                        netif_stop_queue(dev);

                        if (cycx_x25_chan_send(dev, skb))
                                return NETDEV_TX_BUSY;

                        break;
                default:
                        ++chan->ifstats.tx_dropped;
                        ++card->wandev.stats.tx_dropped;
        }
        } else { /* chan->protocol == ETH_P_X25 */
                switch (skb->data[0]) {
                case X25_IFACE_DATA:
                        break;
                case X25_IFACE_CONNECT:
                        cycx_x25_chan_connect(dev);
                        goto free_packet;
                case X25_IFACE_DISCONNECT:
                        cycx_x25_chan_disconnect(dev);
                        goto free_packet;
                default:
                        printk(KERN_INFO
                               "%s: unknown %d x25-iface request on %s!\n",
                               card->devname, skb->data[0], dev->name);
                        ++chan->ifstats.tx_errors;
                        goto free_packet;
                }

                skb_pull(skb, 1); /* Remove control byte */
                reset_timer(dev);
                dev->trans_start = jiffies;
                netif_stop_queue(dev);

                if (cycx_x25_chan_send(dev, skb)) {
                        /* prepare for future retransmissions */
                        skb_push(skb, 1);
                        return NETDEV_TX_BUSY;
                }
        }

free_packet:
        dev_kfree_skb(skb);

        return NETDEV_TX_OK;
}

/* Get Ethernet-style interface statistics.
 * Return a pointer to struct net_device_stats */
static struct net_device_stats *cycx_netdevice_get_stats(struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);

        return chan ? &chan->ifstats : NULL;
}

/* Interrupt Handlers */
/* X.25 Interrupt Service Routine. */
static void cycx_x25_irq_handler(struct cycx_device *card)
{
        struct cycx_x25_cmd cmd;
        u16 z = 0;

        card->in_isr = 1;
        card->buff_int_mode_unbusy = 0;
        cycx_peek(&card->hw, X25_RXMBOX_OFFS, &cmd, sizeof(cmd));

        switch (cmd.command) {
        case X25_DATA_INDICATION:
                cycx_x25_irq_rx(card, &cmd);
                break;
        case X25_ACK_FROM_VC:
                cycx_x25_irq_tx(card, &cmd);
                break;
        case X25_LOG:
                cycx_x25_irq_log(card, &cmd);
                break;
        case X25_STATISTIC:
                cycx_x25_irq_stat(card, &cmd);
                break;
        case X25_CONNECT_CONFIRM:
                cycx_x25_irq_connect_confirm(card, &cmd);
                break;
        case X25_CONNECT_INDICATION:
                cycx_x25_irq_connect(card, &cmd);
                break;
        case X25_DISCONNECT_INDICATION:
                cycx_x25_irq_disconnect(card, &cmd);
                break;
        case X25_DISCONNECT_CONFIRM:
                cycx_x25_irq_disconnect_confirm(card, &cmd);
                break;
        case X25_LINE_ON:
                cycx_set_state(card, WAN_CONNECTED);
                break;
        case X25_LINE_OFF:
                cycx_set_state(card, WAN_DISCONNECTED);
                break;
        default:
                cycx_x25_irq_spurious(card, &cmd);
                break;
        }

        cycx_poke(&card->hw, 0, &z, sizeof(z));
        cycx_poke(&card->hw, X25_RXMBOX_OFFS, &z, sizeof(z));
        card->in_isr = 0;
}

/* Transmit interrupt handler.
 *      o Release socket buffer
 *      o Clear 'tbusy' flag */
static void cycx_x25_irq_tx(struct cycx_device *card, struct cycx_x25_cmd *cmd)
{
        struct net_device *dev;
        struct wan_device *wandev = &card->wandev;
        u8 lcn;

        cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));

        /* unbusy device and then dev_tint(); */
        dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
        if (dev) {
                card->buff_int_mode_unbusy = 1;
                netif_wake_queue(dev);
        } else
                printk(KERN_ERR "%s:ackvc for inexistent lcn %d\n",
                                 card->devname, lcn);
}

/* Receive interrupt handler.
 * This routine handles fragmented IP packets using M-bit according to the
 * RFC1356.
 * o map logical channel number to network interface.
 * o allocate socket buffer or append received packet to the existing one.
 * o if M-bit is reset (i.e. it's the last packet in a sequence) then
 *   decapsulate packet and pass socket buffer to the protocol stack.
 *
 * Notes:
 * 1. When allocating a socket buffer, if M-bit is set then more data is
 *    coming and we have to allocate buffer for the maximum IP packet size
 *    expected on this channel.
 * 2. If something goes wrong and X.25 packet has to be dropped (e.g. no
 *    socket buffers available) the whole packet sequence must be discarded. */
static void cycx_x25_irq_rx(struct cycx_device *card, struct cycx_x25_cmd *cmd)
{
        struct wan_device *wandev = &card->wandev;
        struct net_device *dev;
        struct cycx_x25_channel *chan;
        struct sk_buff *skb;
        u8 bitm, lcn;
        int pktlen = cmd->len - 5;

        cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
        cycx_peek(&card->hw, cmd->buf + 4, &bitm, sizeof(bitm));
        bitm &= 0x10;

        dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
        if (!dev) {
                /* Invalid channel, discard packet */
                printk(KERN_INFO "%s: receiving on orphaned LCN %d!\n",
                                 card->devname, lcn);
                return;
        }

        chan = netdev_priv(dev);
        reset_timer(dev);

        if (chan->drop_sequence) {
                if (!bitm)
                        chan->drop_sequence = 0;
                else
                        return;
        }

        if ((skb = chan->rx_skb) == NULL) {
                /* Allocate new socket buffer */
                int bufsize = bitm ? dev->mtu : pktlen;

                if ((skb = dev_alloc_skb((chan->protocol == ETH_P_X25 ? 1 : 0) +
                                         bufsize +
                                         dev->hard_header_len)) == NULL) {
                        printk(KERN_INFO "%s: no socket buffers available!\n",
                                         card->devname);
                        chan->drop_sequence = 1;
                        ++chan->ifstats.rx_dropped;
                        return;
                }

                if (chan->protocol == ETH_P_X25) /* X.25 socket layer control */
                        /* 0 = data packet (dev_alloc_skb zeroed skb->data) */
                        skb_put(skb, 1);

                skb->dev = dev;
                skb->protocol = htons(chan->protocol);
                chan->rx_skb = skb;
        }

        if (skb_tailroom(skb) < pktlen) {
                /* No room for the packet. Call off the whole thing! */
                dev_kfree_skb_irq(skb);
                chan->rx_skb = NULL;

                if (bitm)
                        chan->drop_sequence = 1;

                printk(KERN_INFO "%s: unexpectedly long packet sequence "
                        "on interface %s!\n", card->devname, dev->name);
                ++chan->ifstats.rx_length_errors;
                return;
        }

        /* Append packet to the socket buffer  */
        cycx_peek(&card->hw, cmd->buf + 5, skb_put(skb, pktlen), pktlen);

        if (bitm)
                return; /* more data is coming */

        chan->rx_skb = NULL;            /* dequeue packet */

        ++chan->ifstats.rx_packets;
        chan->ifstats.rx_bytes += pktlen;

        skb_reset_mac_header(skb);
        netif_rx(skb);
}

/* Connect interrupt handler. */
static void cycx_x25_irq_connect(struct cycx_device *card,
                                 struct cycx_x25_cmd *cmd)
{
        struct wan_device *wandev = &card->wandev;
        struct net_device *dev = NULL;
        struct cycx_x25_channel *chan;
        u8 d[32],
           loc[24],
           rem[24];
        u8 lcn, sizeloc, sizerem;

        cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
        cycx_peek(&card->hw, cmd->buf + 5, &sizeloc, sizeof(sizeloc));
        cycx_peek(&card->hw, cmd->buf + 6, d, cmd->len - 6);

        sizerem = sizeloc >> 4;
        sizeloc &= 0x0F;

        loc[0] = rem[0] = '\0';

        if (sizeloc)
                nibble_to_byte(d, loc, sizeloc, 0);

        if (sizerem)
                nibble_to_byte(d + (sizeloc >> 1), rem, sizerem, sizeloc & 1);

        dprintk(1, KERN_INFO "%s:lcn=%d, local=%s, remote=%s\n",
                          __func__, lcn, loc, rem);

        dev = cycx_x25_get_dev_by_dte_addr(wandev, rem);
        if (!dev) {
                /* Invalid channel, discard packet */
                printk(KERN_INFO "%s: connect not expected: remote %s!\n",
                                 card->devname, rem);
                return;
        }

        chan = netdev_priv(dev);
        chan->lcn = lcn;
        cycx_x25_connect_response(card, chan);
        cycx_x25_set_chan_state(dev, WAN_CONNECTED);
}

/* Connect confirm interrupt handler. */
static void cycx_x25_irq_connect_confirm(struct cycx_device *card,
                                         struct cycx_x25_cmd *cmd)
{
        struct wan_device *wandev = &card->wandev;
        struct net_device *dev;
        struct cycx_x25_channel *chan;
        u8 lcn, key;

        cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
        cycx_peek(&card->hw, cmd->buf + 1, &key, sizeof(key));
        dprintk(1, KERN_INFO "%s: %s:lcn=%d, key=%d\n",
                          card->devname, __func__, lcn, key);

        dev = cycx_x25_get_dev_by_lcn(wandev, -key);
        if (!dev) {
                /* Invalid channel, discard packet */
                clear_bit(--key, (void*)&card->u.x.connection_keys);
                printk(KERN_INFO "%s: connect confirm not expected: lcn %d, "
                                 "key=%d!\n", card->devname, lcn, key);
                return;
        }

        clear_bit(--key, (void*)&card->u.x.connection_keys);
        chan = netdev_priv(dev);
        chan->lcn = lcn;
        cycx_x25_set_chan_state(dev, WAN_CONNECTED);
}

/* Disconnect confirm interrupt handler. */
static void cycx_x25_irq_disconnect_confirm(struct cycx_device *card,
                                            struct cycx_x25_cmd *cmd)
{
        struct wan_device *wandev = &card->wandev;
        struct net_device *dev;
        u8 lcn;

        cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
        dprintk(1, KERN_INFO "%s: %s:lcn=%d\n",
                          card->devname, __func__, lcn);
        dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
        if (!dev) {
                /* Invalid channel, discard packet */
                printk(KERN_INFO "%s:disconnect confirm not expected!:lcn %d\n",
                                 card->devname, lcn);
                return;
        }

        cycx_x25_set_chan_state(dev, WAN_DISCONNECTED);
}

/* disconnect interrupt handler. */
static void cycx_x25_irq_disconnect(struct cycx_device *card,
                                    struct cycx_x25_cmd *cmd)
{
        struct wan_device *wandev = &card->wandev;
        struct net_device *dev;
        u8 lcn;

        cycx_peek(&card->hw, cmd->buf, &lcn, sizeof(lcn));
        dprintk(1, KERN_INFO "%s:lcn=%d\n", __func__, lcn);

        dev = cycx_x25_get_dev_by_lcn(wandev, lcn);
        if (dev) {
                struct cycx_x25_channel *chan = netdev_priv(dev);

                cycx_x25_disconnect_response(card, chan->link, lcn);
                cycx_x25_set_chan_state(dev, WAN_DISCONNECTED);
        } else
                cycx_x25_disconnect_response(card, 0, lcn);
}

/* LOG interrupt handler. */
static void cycx_x25_irq_log(struct cycx_device *card, struct cycx_x25_cmd *cmd)
{
#if CYCLOMX_X25_DEBUG
        char bf[20];
        u16 size, toread, link, msg_code;
        u8 code, routine;

        cycx_peek(&card->hw, cmd->buf, &msg_code, sizeof(msg_code));
        cycx_peek(&card->hw, cmd->buf + 2, &link, sizeof(link));
        cycx_peek(&card->hw, cmd->buf + 4, &size, sizeof(size));
        /* at most 20 bytes are available... thanks to Daniela :) */
        toread = size < 20 ? size : 20;
        cycx_peek(&card->hw, cmd->buf + 10, &bf, toread);
        cycx_peek(&card->hw, cmd->buf + 10 + toread, &code, 1);
        cycx_peek(&card->hw, cmd->buf + 10 + toread + 1, &routine, 1);

        printk(KERN_INFO "cycx_x25_irq_handler: X25_LOG (0x4500) indic.:\n");
        printk(KERN_INFO "cmd->buf=0x%X\n", cmd->buf);
        printk(KERN_INFO "Log message code=0x%X\n", msg_code);
        printk(KERN_INFO "Link=%d\n", link);
        printk(KERN_INFO "log code=0x%X\n", code);
        printk(KERN_INFO "log routine=0x%X\n", routine);
        printk(KERN_INFO "Message size=%d\n", size);
        hex_dump("Message", bf, toread);
#endif
}

/* STATISTIC interrupt handler. */
static void cycx_x25_irq_stat(struct cycx_device *card,
                              struct cycx_x25_cmd *cmd)
{
        cycx_peek(&card->hw, cmd->buf, &card->u.x.stats,
                  sizeof(card->u.x.stats));
        hex_dump("cycx_x25_irq_stat", (unsigned char*)&card->u.x.stats,
                 sizeof(card->u.x.stats));
        cycx_x25_dump_stats(&card->u.x.stats);
        wake_up_interruptible(&card->wait_stats);
}

/* Spurious interrupt handler.
 * o print a warning
 * If number of spurious interrupts exceeded some limit, then ??? */
static void cycx_x25_irq_spurious(struct cycx_device *card,
                                  struct cycx_x25_cmd *cmd)
{
        printk(KERN_INFO "%s: spurious interrupt (0x%X)!\n",
                         card->devname, cmd->command);
}
#ifdef CYCLOMX_X25_DEBUG
static void hex_dump(char *msg, unsigned char *p, int len)
{
        unsigned char hex[1024],
                * phex = hex;

        if (len >= (sizeof(hex) / 2))
                len = (sizeof(hex) / 2) - 1;

        while (len--) {
                sprintf(phex, "%02x", *p++);
                phex += 2;
        }

        printk(KERN_INFO "%s: %s\n", msg, hex);
}
#endif

/* Cyclom 2X Firmware-Specific Functions */
/* Exec X.25 command. */
static int x25_exec(struct cycx_device *card, int command, int link,
                    void *d1, int len1, void *d2, int len2)
{
        struct cycx_x25_cmd c;
        unsigned long flags;
        u32 addr = 0x1200 + 0x2E0 * link + 0x1E2;
        u8 retry = CYCX_X25_MAX_CMD_RETRY;
        int err = 0;

        c.command = command;
        c.link = link;
        c.len = len1 + len2;

        spin_lock_irqsave(&card->u.x.lock, flags);

        /* write command */
        cycx_poke(&card->hw, X25_MBOX_OFFS, &c, sizeof(c) - sizeof(c.buf));

        /* write X.25 data */
        if (d1) {
                cycx_poke(&card->hw, addr, d1, len1);

                if (d2) {
                        if (len2 > 254) {
                                u32 addr1 = 0xA00 + 0x400 * link;

                                cycx_poke(&card->hw, addr + len1, d2, 249);
                                cycx_poke(&card->hw, addr1, ((u8*)d2) + 249,
                                          len2 - 249);
                        } else
                                cycx_poke(&card->hw, addr + len1, d2, len2);
                }
        }

        /* generate interruption, executing command */
        cycx_intr(&card->hw);

        /* wait till card->mbox == 0 */
        do {
                err = cycx_exec(card->mbox);
        } while (retry-- && err);

        spin_unlock_irqrestore(&card->u.x.lock, flags);

        return err;
}

/* Configure adapter. */
static int cycx_x25_configure(struct cycx_device *card,
                              struct cycx_x25_config *conf)
{
        struct {
                u16 nlinks;
                struct cycx_x25_config conf[2];
        } x25_cmd_conf;

        memset(&x25_cmd_conf, 0, sizeof(x25_cmd_conf));
        x25_cmd_conf.nlinks = 2;
        x25_cmd_conf.conf[0] = *conf;
        x25_cmd_conf.conf[1] = *conf;
        x25_cmd_conf.conf[1].link = 1;
        x25_cmd_conf.conf[1].speed = 5; /* 38400 */
        x25_cmd_conf.conf[1].clock = 8;
        x25_cmd_conf.conf[1].flags = 0; /* default = RS232 */

        cycx_x25_dump_config(&x25_cmd_conf.conf[0]);
        cycx_x25_dump_config(&x25_cmd_conf.conf[1]);

        return x25_exec(card, X25_CONFIG, 0,
                        &x25_cmd_conf, sizeof(x25_cmd_conf), NULL, 0);
}

/* Get protocol statistics. */
static int cycx_x25_get_stats(struct cycx_device *card)
{
        /* the firmware expects 20 in the size field!!!
           thanks to Daniela */
        int err = x25_exec(card, X25_STATISTIC, 0, NULL, 20, NULL, 0);

        if (err)
                return err;

        interruptible_sleep_on(&card->wait_stats);

        if (signal_pending(current))
                return -EINTR;

        card->wandev.stats.rx_packets = card->u.x.stats.n2_rx_frames;
        card->wandev.stats.rx_over_errors = card->u.x.stats.rx_over_errors;
        card->wandev.stats.rx_crc_errors = card->u.x.stats.rx_crc_errors;
        card->wandev.stats.rx_length_errors = 0; /* not available from fw */
        card->wandev.stats.rx_frame_errors = 0; /* not available from fw */
        card->wandev.stats.rx_missed_errors = card->u.x.stats.rx_aborts;
        card->wandev.stats.rx_dropped = 0; /* not available from fw */
        card->wandev.stats.rx_errors = 0; /* not available from fw */
        card->wandev.stats.tx_packets = card->u.x.stats.n2_tx_frames;
        card->wandev.stats.tx_aborted_errors = card->u.x.stats.tx_aborts;
        card->wandev.stats.tx_dropped = 0; /* not available from fw */
        card->wandev.stats.collisions = 0; /* not available from fw */
        card->wandev.stats.tx_errors = 0; /* not available from fw */

        cycx_x25_dump_devs(&card->wandev);

        return 0;
}

/* return the number of nibbles */
static int byte_to_nibble(u8 *s, u8 *d, char *nibble)
{
        int i = 0;

        if (*nibble && *s) {
                d[i] |= *s++ - '0';
                *nibble = 0;
                ++i;
        }

        while (*s) {
                d[i] = (*s - '0') << 4;
                if (*(s + 1))
                        d[i] |= *(s + 1) - '0';
                else {
                        *nibble = 1;
                        break;
                }
                ++i;
                s += 2;
        }

        return i;
}

static void nibble_to_byte(u8 *s, u8 *d, u8 len, u8 nibble)
{
        if (nibble) {
                *d++ = '0' + (*s++ & 0x0F);
                --len;
        }

        while (len) {
                *d++ = '0' + (*s >> 4);

                if (--len) {
                        *d++ = '0' + (*s & 0x0F);
                        --len;
                } else break;

                ++s;
        }

        *d = '\0';
}

/* Place X.25 call. */
static int x25_place_call(struct cycx_device *card,
                          struct cycx_x25_channel *chan)
{
        int err = 0,
            len;
        char d[64],
             nibble = 0,
             mylen = chan->local_addr ? strlen(chan->local_addr) : 0,
             remotelen = strlen(chan->addr);
        u8 key;

        if (card->u.x.connection_keys == ~0U) {
                printk(KERN_INFO "%s: too many simultaneous connection "
                                 "requests!\n", card->devname);
                return -EAGAIN;
        }

        key = ffz(card->u.x.connection_keys);
        set_bit(key, (void*)&card->u.x.connection_keys);
        ++key;
        dprintk(1, KERN_INFO "%s:x25_place_call:key=%d\n", card->devname, key);
        memset(d, 0, sizeof(d));
        d[1] = key; /* user key */
        d[2] = 0x10;
        d[4] = 0x0B;

        len = byte_to_nibble(chan->addr, d + 6, &nibble);

        if (chan->local_addr)
                len += byte_to_nibble(chan->local_addr, d + 6 + len, &nibble);

        if (nibble)
                ++len;

        d[5] = mylen << 4 | remotelen;
        d[6 + len + 1] = 0xCC; /* TCP/IP over X.25, thanks to Daniela :) */

        if ((err = x25_exec(card, X25_CONNECT_REQUEST, chan->link,
                            &d, 7 + len + 1, NULL, 0)) != 0)
                clear_bit(--key, (void*)&card->u.x.connection_keys);
        else
                chan->lcn = -key;

        return err;
}

/* Place X.25 CONNECT RESPONSE. */
static int cycx_x25_connect_response(struct cycx_device *card,
                                     struct cycx_x25_channel *chan)
{
        u8 d[8];

        memset(d, 0, sizeof(d));
        d[0] = d[3] = chan->lcn;
        d[2] = 0x10;
        d[4] = 0x0F;
        d[7] = 0xCC; /* TCP/IP over X.25, thanks Daniela */

        return x25_exec(card, X25_CONNECT_RESPONSE, chan->link, &d, 8, NULL, 0);
}

/* Place X.25 DISCONNECT RESPONSE.  */
static int cycx_x25_disconnect_response(struct cycx_device *card, u8 link,
                                        u8 lcn)
{
        char d[5];

        memset(d, 0, sizeof(d));
        d[0] = d[3] = lcn;
        d[2] = 0x10;
        d[4] = 0x17;

        return x25_exec(card, X25_DISCONNECT_RESPONSE, link, &d, 5, NULL, 0);
}

/* Clear X.25 call.  */
static int x25_clear_call(struct cycx_device *card, u8 link, u8 lcn, u8 cause,
                          u8 diagn)
{
        u8 d[7];

        memset(d, 0, sizeof(d));
        d[0] = d[3] = lcn;
        d[2] = 0x10;
        d[4] = 0x13;
        d[5] = cause;
        d[6] = diagn;

        return x25_exec(card, X25_DISCONNECT_REQUEST, link, d, 7, NULL, 0);
}

/* Send X.25 data packet. */
static int cycx_x25_send(struct cycx_device *card, u8 link, u8 lcn, u8 bitm,
                         int len, void *buf)
{
        u8 d[] = "?\xFF\x10??";

        d[0] = d[3] = lcn;
        d[4] = bitm;

        return x25_exec(card, X25_DATA_REQUEST, link, &d, 5, buf, len);
}

/* Miscellaneous */
/* Find network device by its channel number.  */
static struct net_device *cycx_x25_get_dev_by_lcn(struct wan_device *wandev,
                                                  s16 lcn)
{
        struct net_device *dev = wandev->dev;
        struct cycx_x25_channel *chan;

        while (dev) {
                chan = netdev_priv(dev);

                if (chan->lcn == lcn)
                        break;
                dev = chan->slave;
        }
        return dev;
}

/* Find network device by its remote dte address. */
static struct net_device *
        cycx_x25_get_dev_by_dte_addr(struct wan_device *wandev, char *dte)
{
        struct net_device *dev = wandev->dev;
        struct cycx_x25_channel *chan;

        while (dev) {
                chan = netdev_priv(dev);

                if (!strcmp(chan->addr, dte))
                        break;
                dev = chan->slave;
        }
        return dev;
}

/* Initiate connection on the logical channel.
 * o for PVC we just get channel configuration
 * o for SVCs place an X.25 call
 *
 * Return:      0       connected
 *              >0      connection in progress
 *              <0      failure */
static int cycx_x25_chan_connect(struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);
        struct cycx_device *card = chan->card;

        if (chan->svc) {
                if (!chan->addr[0])
                        return -EINVAL; /* no destination address */

                dprintk(1, KERN_INFO "%s: placing X.25 call to %s...\n",
                                  card->devname, chan->addr);

                if (x25_place_call(card, chan))
                        return -EIO;

                cycx_x25_set_chan_state(dev, WAN_CONNECTING);
                return 1;
        } else
                cycx_x25_set_chan_state(dev, WAN_CONNECTED);

        return 0;
}

/* Disconnect logical channel.
 * o if SVC then clear X.25 call */
static void cycx_x25_chan_disconnect(struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);

        if (chan->svc) {
                x25_clear_call(chan->card, chan->link, chan->lcn, 0, 0);
                cycx_x25_set_chan_state(dev, WAN_DISCONNECTING);
        } else
                cycx_x25_set_chan_state(dev, WAN_DISCONNECTED);
}

/* Called by kernel timer */
static void cycx_x25_chan_timer(unsigned long d)
{
        struct net_device *dev = (struct net_device *)d;
        struct cycx_x25_channel *chan = netdev_priv(dev);

        if (chan->state == WAN_CONNECTED)
                cycx_x25_chan_disconnect(dev);
        else
                printk(KERN_ERR "%s: %s for svc (%s) not connected!\n",
                                chan->card->devname, __func__, dev->name);
}

/* Set logical channel state. */
static void cycx_x25_set_chan_state(struct net_device *dev, u8 state)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);
        struct cycx_device *card = chan->card;
        unsigned long flags;
        char *string_state = NULL;

        spin_lock_irqsave(&card->lock, flags);

        if (chan->state != state) {
                if (chan->svc && chan->state == WAN_CONNECTED)
                        del_timer(&chan->timer);

                switch (state) {
                case WAN_CONNECTED:
                        string_state = "connected!";
                        *(__be16*)dev->dev_addr = htons(chan->lcn);
                        netif_wake_queue(dev);
                        reset_timer(dev);

                        if (chan->protocol == ETH_P_X25)
                                cycx_x25_chan_send_event(dev,
                                        X25_IFACE_CONNECT);

                        break;
                case WAN_CONNECTING:
                        string_state = "connecting...";
                        break;
                case WAN_DISCONNECTING:
                        string_state = "disconnecting...";
                        break;
                case WAN_DISCONNECTED:
                        string_state = "disconnected!";

                        if (chan->svc) {
                                *(unsigned short*)dev->dev_addr = 0;
                                chan->lcn = 0;
                        }

                        if (chan->protocol == ETH_P_X25)
                                cycx_x25_chan_send_event(dev,
                                        X25_IFACE_DISCONNECT);

                        netif_wake_queue(dev);
                        break;
                }

                printk(KERN_INFO "%s: interface %s %s\n", card->devname,
                                  dev->name, string_state);
                chan->state = state;
        }

        spin_unlock_irqrestore(&card->lock, flags);
}

/* Send packet on a logical channel.
 *      When this function is called, tx_skb field of the channel data space
 *      points to the transmit socket buffer.  When transmission is complete,
 *      release socket buffer and reset 'tbusy' flag.
 *
 * Return:      0       - transmission complete
 *              1       - busy
 *
 * Notes:
 * 1. If packet length is greater than MTU for this channel, we'll fragment
 *    the packet into 'complete sequence' using M-bit.
 * 2. When transmission is complete, an event notification should be issued
 *    to the router.  */
static int cycx_x25_chan_send(struct net_device *dev, struct sk_buff *skb)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);
        struct cycx_device *card = chan->card;
        int bitm = 0;           /* final packet */
        unsigned len = skb->len;

        if (skb->len > card->wandev.mtu) {
                len = card->wandev.mtu;
                bitm = 0x10;            /* set M-bit (more data) */
        }

        if (cycx_x25_send(card, chan->link, chan->lcn, bitm, len, skb->data))
                return 1;

        if (bitm) {
                skb_pull(skb, len);
                return 1;
        }

        ++chan->ifstats.tx_packets;
        chan->ifstats.tx_bytes += len;

        return 0;
}

/* Send event (connection, disconnection, etc) to X.25 socket layer */

static void cycx_x25_chan_send_event(struct net_device *dev, u8 event)
{
        struct sk_buff *skb;
        unsigned char *ptr;

        if ((skb = dev_alloc_skb(1)) == NULL) {
                printk(KERN_ERR "%s: out of memory\n", __func__);
                return;
        }

        ptr  = skb_put(skb, 1);
        *ptr = event;

        skb->protocol = x25_type_trans(skb, dev);
        netif_rx(skb);
}

/* Convert line speed in bps to a number used by cyclom 2x code. */
static u8 bps_to_speed_code(u32 bps)
{
        u8 number = 0; /* defaults to the lowest (1200) speed ;> */

             if (bps >= 512000) number = 8;
        else if (bps >= 256000) number = 7;
        else if (bps >= 64000)  number = 6;
        else if (bps >= 38400)  number = 5;
        else if (bps >= 19200)  number = 4;
        else if (bps >= 9600)   number = 3;
        else if (bps >= 4800)   number = 2;
        else if (bps >= 2400)   number = 1;

        return number;
}

/* log base 2 */
static u8 cycx_log2(u32 n)
{
        u8 log = 0;

        if (!n)
                return 0;

        while (n > 1) {
                n >>= 1;
                ++log;
        }

        return log;
}

/* Convert decimal string to unsigned integer.
 * If len != 0 then only 'len' characters of the string are converted. */
static unsigned dec_to_uint(u8 *str, int len)
{
        unsigned val = 0;

        if (!len)
                len = strlen(str);

        for (; len && isdigit(*str); ++str, --len)
                val = (val * 10) + (*str - (unsigned) '0');

        return val;
}

static void reset_timer(struct net_device *dev)
{
        struct cycx_x25_channel *chan = netdev_priv(dev);

        if (chan->svc)
                mod_timer(&chan->timer, jiffies+chan->idle_tmout*HZ);
}
#ifdef CYCLOMX_X25_DEBUG
static void cycx_x25_dump_config(struct cycx_x25_config *conf)
{
        printk(KERN_INFO "X.25 configuration\n");
        printk(KERN_INFO "-----------------\n");
        printk(KERN_INFO "link number=%d\n", conf->link);
        printk(KERN_INFO "line speed=%d\n", conf->speed);
        printk(KERN_INFO "clock=%sternal\n", conf->clock == 8 ? "Ex" : "In");
        printk(KERN_INFO "# level 2 retransm.=%d\n", conf->n2);
        printk(KERN_INFO "level 2 window=%d\n", conf->n2win);
        printk(KERN_INFO "level 3 window=%d\n", conf->n3win);
        printk(KERN_INFO "# logical channels=%d\n", conf->nvc);
        printk(KERN_INFO "level 3 pkt len=%d\n", conf->pktlen);
        printk(KERN_INFO "my address=%d\n", conf->locaddr);
        printk(KERN_INFO "remote address=%d\n", conf->remaddr);
        printk(KERN_INFO "t1=%d seconds\n", conf->t1);
        printk(KERN_INFO "t2=%d seconds\n", conf->t2);
        printk(KERN_INFO "t21=%d seconds\n", conf->t21);
        printk(KERN_INFO "# PVCs=%d\n", conf->npvc);
        printk(KERN_INFO "t23=%d seconds\n", conf->t23);
        printk(KERN_INFO "flags=0x%x\n", conf->flags);
}

static void cycx_x25_dump_stats(struct cycx_x25_stats *stats)
{
        printk(KERN_INFO "X.25 statistics\n");
        printk(KERN_INFO "--------------\n");
        printk(KERN_INFO "rx_crc_errors=%d\n", stats->rx_crc_errors);
        printk(KERN_INFO "rx_over_errors=%d\n", stats->rx_over_errors);
        printk(KERN_INFO "n2_tx_frames=%d\n", stats->n2_tx_frames);
        printk(KERN_INFO "n2_rx_frames=%d\n", stats->n2_rx_frames);
        printk(KERN_INFO "tx_timeouts=%d\n", stats->tx_timeouts);
        printk(KERN_INFO "rx_timeouts=%d\n", stats->rx_timeouts);
        printk(KERN_INFO "n3_tx_packets=%d\n", stats->n3_tx_packets);
        printk(KERN_INFO "n3_rx_packets=%d\n", stats->n3_rx_packets);
        printk(KERN_INFO "tx_aborts=%d\n", stats->tx_aborts);
        printk(KERN_INFO "rx_aborts=%d\n", stats->rx_aborts);
}

static void cycx_x25_dump_devs(struct wan_device *wandev)
{
        struct net_device *dev = wandev->dev;

        printk(KERN_INFO "X.25 dev states\n");
        printk(KERN_INFO "name: addr:           txoff:  protocol:\n");
        printk(KERN_INFO "---------------------------------------\n");

        while(dev) {
                struct cycx_x25_channel *chan = netdev_priv(dev);

                printk(KERN_INFO "%-5.5s %-15.15s   %d     ETH_P_%s\n",
                                 chan->name, chan->addr, netif_queue_stopped(dev),
                                 chan->protocol == ETH_P_IP ? "IP" : "X25");
                dev = chan->slave;
        }
}

#endif /* CYCLOMX_X25_DEBUG */
/* End */