sdla.c

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/*
 * SDLA     An implementation of a driver for the Sangoma S502/S508 series
 *      multi-protocol PC interface card.  Initial offering is with 
 *      the DLCI driver, providing Frame Relay support for linux.
 *
 *      Global definitions for the Frame relay interface.
 *
 * Version: @(#)sdla.c   0.30   12 Sep 1996
 *
 * Credits: Sangoma Technologies, for the use of 2 cards for an extended
 *          period of time.
 *      David Mandelstam <[email protected]> for getting me started on 
 *          this project, and incentive to complete it.
 *      Gene Kozen <[email protected]> for providing me with
 *          important information about the cards.
 *
 * Author:  Mike McLagan <[email protected]>
 *
 * Changes:
 *      0.15    Mike McLagan    Improved error handling, packet dropping
 *      0.20    Mike McLagan    New transmit/receive flags for config
 *                  If in FR mode, don't accept packets from
 *                  non DLCI devices.
 *      0.25    Mike McLagan    Fixed problem with rejecting packets
 *                  from non DLCI devices.
 *      0.30    Mike McLagan    Fixed kernel panic when used with modified
 *                  ifconfig
 *
 *      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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/if_frad.h>
#include <linux/sdla.h>
#include <linux/bitops.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>

static const char* version = "SDLA driver v0.30, 12 Sep 1996, [email protected]";

static unsigned int valid_port[] = { 0x250, 0x270, 0x280, 0x300, 0x350, 0x360, 0x380, 0x390};

static unsigned int valid_mem[] = {
                    0xA0000, 0xA2000, 0xA4000, 0xA6000, 0xA8000, 0xAA000, 0xAC000, 0xAE000, 
                                    0xB0000, 0xB2000, 0xB4000, 0xB6000, 0xB8000, 0xBA000, 0xBC000, 0xBE000,
                                    0xC0000, 0xC2000, 0xC4000, 0xC6000, 0xC8000, 0xCA000, 0xCC000, 0xCE000,
                                    0xD0000, 0xD2000, 0xD4000, 0xD6000, 0xD8000, 0xDA000, 0xDC000, 0xDE000,
                                    0xE0000, 0xE2000, 0xE4000, 0xE6000, 0xE8000, 0xEA000, 0xEC000, 0xEE000}; 

static DEFINE_SPINLOCK(sdla_lock);

/*********************************************************
 *
 * these are the core routines that access the card itself 
 *
 *********************************************************/

#define SDLA_WINDOW(dev,addr) outb((((addr) >> 13) & 0x1F), (dev)->base_addr + SDLA_REG_Z80_WINDOW)

static void __sdla_read(struct net_device *dev, int addr, void *buf, short len)
{
    char          *temp;
    const void    *base;
    int           offset, bytes;

    temp = buf;
    while(len)
    {   
        offset = addr & SDLA_ADDR_MASK;
        bytes = offset + len > SDLA_WINDOW_SIZE ? SDLA_WINDOW_SIZE - offset : len;
        base = (const void *) (dev->mem_start + offset);

        SDLA_WINDOW(dev, addr);
        memcpy(temp, base, bytes);

        addr += bytes;
        temp += bytes;
        len  -= bytes;
    }  
}

static void sdla_read(struct net_device *dev, int addr, void *buf, short len)
{
    unsigned long flags;
    spin_lock_irqsave(&sdla_lock, flags);
    __sdla_read(dev, addr, buf, len);
    spin_unlock_irqrestore(&sdla_lock, flags);
}

static void __sdla_write(struct net_device *dev, int addr, 
             const void *buf, short len)
{
    const char    *temp;
    void          *base;
    int           offset, bytes;

    temp = buf;
    while(len)
    {
        offset = addr & SDLA_ADDR_MASK;
        bytes = offset + len > SDLA_WINDOW_SIZE ? SDLA_WINDOW_SIZE - offset : len;
        base = (void *) (dev->mem_start + offset);

        SDLA_WINDOW(dev, addr);
        memcpy(base, temp, bytes);

        addr += bytes;
        temp += bytes;
        len  -= bytes;
    }
}

static void sdla_write(struct net_device *dev, int addr, 
               const void *buf, short len)
{
    unsigned long flags;

    spin_lock_irqsave(&sdla_lock, flags);
    __sdla_write(dev, addr, buf, len);
    spin_unlock_irqrestore(&sdla_lock, flags);
}


static void sdla_clear(struct net_device *dev)
{
    unsigned long flags;
    char          *base;
    int           len, addr, bytes;

    len = 65536;    
    addr = 0;
    bytes = SDLA_WINDOW_SIZE;
    base = (void *) dev->mem_start;

    spin_lock_irqsave(&sdla_lock, flags);
    while(len)
    {
        SDLA_WINDOW(dev, addr);
        memset(base, 0, bytes);

        addr += bytes;
        len  -= bytes;
    }
    spin_unlock_irqrestore(&sdla_lock, flags);

}

static char sdla_byte(struct net_device *dev, int addr)
{
    unsigned long flags;
    char          byte, *temp;

    temp = (void *) (dev->mem_start + (addr & SDLA_ADDR_MASK));

    spin_lock_irqsave(&sdla_lock, flags);
    SDLA_WINDOW(dev, addr);
    byte = *temp;
    spin_unlock_irqrestore(&sdla_lock, flags);

    return byte;
}

static void sdla_stop(struct net_device *dev)
{
    struct frad_local *flp;

    flp = netdev_priv(dev);
    switch(flp->type)
    {
        case SDLA_S502A:
            outb(SDLA_S502A_HALT, dev->base_addr + SDLA_REG_CONTROL);
            flp->state = SDLA_HALT;
            break;
        case SDLA_S502E:
            outb(SDLA_HALT, dev->base_addr + SDLA_REG_Z80_CONTROL);
            outb(SDLA_S502E_ENABLE, dev->base_addr + SDLA_REG_CONTROL);
            flp->state = SDLA_S502E_ENABLE;
            break;
        case SDLA_S507:
            flp->state &= ~SDLA_CPUEN;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            break;
        case SDLA_S508:
            flp->state &= ~SDLA_CPUEN;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            break;
    }
}

static void sdla_start(struct net_device *dev)
{
    struct frad_local *flp;

    flp = netdev_priv(dev);
    switch(flp->type)
    {
        case SDLA_S502A:
            outb(SDLA_S502A_NMI, dev->base_addr + SDLA_REG_CONTROL);
            outb(SDLA_S502A_START, dev->base_addr + SDLA_REG_CONTROL);
            flp->state = SDLA_S502A_START;
            break;
        case SDLA_S502E:
            outb(SDLA_S502E_CPUEN, dev->base_addr + SDLA_REG_Z80_CONTROL);
            outb(0x00, dev->base_addr + SDLA_REG_CONTROL);
            flp->state = 0;
            break;
        case SDLA_S507:
            flp->state |= SDLA_CPUEN;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            break;
        case SDLA_S508:
            flp->state |= SDLA_CPUEN;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            break;
    }
}

/****************************************************
 *
 * this is used for the S502A/E cards to determine
 * the speed of the onboard CPU.  Calibration is
 * necessary for the Frame Relay code uploaded 
 * later.  Incorrect results cause timing problems
 * with link checks & status messages
 *
 ***************************************************/

static int sdla_z80_poll(struct net_device *dev, int z80_addr, int jiffs, char resp1, char resp2)
{
    unsigned long start, done, now;
    char          resp, *temp;

    start = now = jiffies;
    done = jiffies + jiffs;

    temp = (void *)dev->mem_start;
    temp += z80_addr & SDLA_ADDR_MASK;
    
    resp = ~resp1;
    while (time_before(jiffies, done) && (resp != resp1) && (!resp2 || (resp != resp2)))
    {
        if (jiffies != now)
        {
            SDLA_WINDOW(dev, z80_addr);
            now = jiffies;
            resp = *temp;
        }
    }
    return time_before(jiffies, done) ? jiffies - start : -1;
}

/* constants for Z80 CPU speed */
#define Z80_READY       '1' /* Z80 is ready to begin */
#define LOADER_READY        '2' /* driver is ready to begin */
#define Z80_SCC_OK      '3' /* SCC is on board */
#define Z80_SCC_BAD     '4' /* SCC was not found */

static int sdla_cpuspeed(struct net_device *dev, struct ifreq *ifr)
{
    int  jiffs;
    char data;

    sdla_start(dev);
    if (sdla_z80_poll(dev, 0, 3*HZ, Z80_READY, 0) < 0)
        return -EIO;

    data = LOADER_READY;
    sdla_write(dev, 0, &data, 1);

    if ((jiffs = sdla_z80_poll(dev, 0, 8*HZ, Z80_SCC_OK, Z80_SCC_BAD)) < 0)
        return -EIO;

    sdla_stop(dev);
    sdla_read(dev, 0, &data, 1);

    if (data == Z80_SCC_BAD)
    {
        printk("%s: SCC bad\n", dev->name);
        return -EIO;
    }

    if (data != Z80_SCC_OK)
        return -EINVAL;

    if (jiffs < 165)
        ifr->ifr_mtu = SDLA_CPU_16M;
    else if (jiffs < 220)
        ifr->ifr_mtu = SDLA_CPU_10M;
    else if (jiffs < 258)
        ifr->ifr_mtu = SDLA_CPU_8M;
    else if (jiffs < 357)
        ifr->ifr_mtu = SDLA_CPU_7M;
    else if (jiffs < 467)
        ifr->ifr_mtu = SDLA_CPU_5M;
    else
        ifr->ifr_mtu = SDLA_CPU_3M;
 
    return 0;
}

/************************************************
 *
 *  Direct interaction with the Frame Relay code 
 *  starts here.
 *
 ************************************************/

struct _dlci_stat 
{
    short dlci;
    char  flags;
} __packed;

struct _frad_stat 
{
    char    flags;
    struct _dlci_stat dlcis[SDLA_MAX_DLCI];
};

static void sdla_errors(struct net_device *dev, int cmd, int dlci, int ret, int len, void *data) 
{
    struct _dlci_stat *pstatus;
    short             *pdlci;
    int               i;
    char              *state, line[30];

    switch (ret)
    {
        case SDLA_RET_MODEM:
            state = data;
            if (*state & SDLA_MODEM_DCD_LOW)
                netdev_info(dev, "Modem DCD unexpectedly low!\n");
            if (*state & SDLA_MODEM_CTS_LOW)
                netdev_info(dev, "Modem CTS unexpectedly low!\n");
            /* I should probably do something about this! */
            break;

        case SDLA_RET_CHANNEL_OFF:
            netdev_info(dev, "Channel became inoperative!\n");
            /* same here */
            break;

        case SDLA_RET_CHANNEL_ON:
            netdev_info(dev, "Channel became operative!\n");
            /* same here */
            break;

        case SDLA_RET_DLCI_STATUS:
            netdev_info(dev, "Status change reported by Access Node\n");
            len /= sizeof(struct _dlci_stat);
            for(pstatus = data, i=0;i < len;i++,pstatus++)
            {
                if (pstatus->flags & SDLA_DLCI_NEW)
                    state = "new";
                else if (pstatus->flags & SDLA_DLCI_DELETED)
                    state = "deleted";
                else if (pstatus->flags & SDLA_DLCI_ACTIVE)
                    state = "active";
                else
                {
                    sprintf(line, "unknown status: %02X", pstatus->flags);
                    state = line;
                }
                netdev_info(dev, "DLCI %i: %s\n",
                        pstatus->dlci, state);
                /* same here */
            }
            break;

        case SDLA_RET_DLCI_UNKNOWN:
            netdev_info(dev, "Received unknown DLCIs:");
            len /= sizeof(short);
            for(pdlci = data,i=0;i < len;i++,pdlci++)
                pr_cont(" %i", *pdlci);
            pr_cont("\n");
            break;

        case SDLA_RET_TIMEOUT:
            netdev_err(dev, "Command timed out!\n");
            break;

        case SDLA_RET_BUF_OVERSIZE:
            netdev_info(dev, "Bc/CIR overflow, acceptable size is %i\n",
                    len);
            break;

        case SDLA_RET_BUF_TOO_BIG:
            netdev_info(dev, "Buffer size over specified max of %i\n",
                    len);
            break;

        case SDLA_RET_CHANNEL_INACTIVE:
        case SDLA_RET_DLCI_INACTIVE:
        case SDLA_RET_CIR_OVERFLOW:
        case SDLA_RET_NO_BUFS:
            if (cmd == SDLA_INFORMATION_WRITE)
                break;

        default: 
            netdev_dbg(dev, "Cmd 0x%02X generated return code 0x%02X\n",
                   cmd, ret);
            /* Further processing could be done here */
            break;
    }
}

static int sdla_cmd(struct net_device *dev, int cmd, short dlci, short flags, 
                        void *inbuf, short inlen, void *outbuf, short *outlen)
{
    static struct _frad_stat status;
    struct frad_local        *flp;
    struct sdla_cmd          *cmd_buf;
    unsigned long            pflags;
    unsigned long        jiffs;
    int                      ret, waiting, len;
    long                     window;

    flp = netdev_priv(dev);
    window = flp->type == SDLA_S508 ? SDLA_508_CMD_BUF : SDLA_502_CMD_BUF;
    cmd_buf = (struct sdla_cmd *)(dev->mem_start + (window & SDLA_ADDR_MASK));
    ret = 0;
    len = 0;
    jiffs = jiffies + HZ;  /* 1 second is plenty */

    spin_lock_irqsave(&sdla_lock, pflags);
    SDLA_WINDOW(dev, window);
    cmd_buf->cmd = cmd;
    cmd_buf->dlci = dlci;
    cmd_buf->flags = flags;

    if (inbuf)
        memcpy(cmd_buf->data, inbuf, inlen);

    cmd_buf->length = inlen;

    cmd_buf->opp_flag = 1;
    spin_unlock_irqrestore(&sdla_lock, pflags);

    waiting = 1;
    len = 0;
    while (waiting && time_before_eq(jiffies, jiffs))
    {
        if (waiting++ % 3) 
        {
            spin_lock_irqsave(&sdla_lock, pflags);
            SDLA_WINDOW(dev, window);
            waiting = ((volatile int)(cmd_buf->opp_flag));
            spin_unlock_irqrestore(&sdla_lock, pflags);
        }
    }
    
    if (!waiting)
    {

        spin_lock_irqsave(&sdla_lock, pflags);
        SDLA_WINDOW(dev, window);
        ret = cmd_buf->retval;
        len = cmd_buf->length;
        if (outbuf && outlen)
        {
            *outlen = *outlen >= len ? len : *outlen;

            if (*outlen)
                memcpy(outbuf, cmd_buf->data, *outlen);
        }

        /* This is a local copy that's used for error handling */
        if (ret)
            memcpy(&status, cmd_buf->data, len > sizeof(status) ? sizeof(status) : len);

        spin_unlock_irqrestore(&sdla_lock, pflags);
    }
    else
        ret = SDLA_RET_TIMEOUT;

    if (ret != SDLA_RET_OK)
        sdla_errors(dev, cmd, dlci, ret, len, &status);

    return ret;
}

/***********************************************
 *
 * these functions are called by the DLCI driver 
 *
 ***********************************************/

static int sdla_reconfig(struct net_device *dev);

static int sdla_activate(struct net_device *slave, struct net_device *master)
{
    struct frad_local *flp;
    int i;

    flp = netdev_priv(slave);

    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->master[i] == master)
            break;

    if (i == CONFIG_DLCI_MAX)
        return -ENODEV;

    flp->dlci[i] = abs(flp->dlci[i]);

    if (netif_running(slave) && (flp->config.station == FRAD_STATION_NODE))
        sdla_cmd(slave, SDLA_ACTIVATE_DLCI, 0, 0, &flp->dlci[i], sizeof(short), NULL, NULL);

    return 0;
}

static int sdla_deactivate(struct net_device *slave, struct net_device *master)
{
    struct frad_local *flp;
    int               i;

    flp = netdev_priv(slave);

    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->master[i] == master)
            break;

    if (i == CONFIG_DLCI_MAX)
        return -ENODEV;

    flp->dlci[i] = -abs(flp->dlci[i]);

    if (netif_running(slave) && (flp->config.station == FRAD_STATION_NODE))
        sdla_cmd(slave, SDLA_DEACTIVATE_DLCI, 0, 0, &flp->dlci[i], sizeof(short), NULL, NULL);

    return 0;
}

static int sdla_assoc(struct net_device *slave, struct net_device *master)
{
    struct frad_local *flp;
    int               i;

    if (master->type != ARPHRD_DLCI)
        return -EINVAL;

    flp = netdev_priv(slave);

    for(i=0;i<CONFIG_DLCI_MAX;i++)
    {
        if (!flp->master[i])
            break;
        if (abs(flp->dlci[i]) == *(short *)(master->dev_addr))
            return -EADDRINUSE;
    } 

    if (i == CONFIG_DLCI_MAX)
        return -EMLINK;  /* #### Alan: Comments on this ?? */


    flp->master[i] = master;
    flp->dlci[i] = -*(short *)(master->dev_addr);
    master->mtu = slave->mtu;

    if (netif_running(slave)) {
        if (flp->config.station == FRAD_STATION_CPE)
            sdla_reconfig(slave);
        else
            sdla_cmd(slave, SDLA_ADD_DLCI, 0, 0, master->dev_addr, sizeof(short), NULL, NULL);
    }

    return 0;
}

static int sdla_deassoc(struct net_device *slave, struct net_device *master)
{
    struct frad_local *flp;
    int               i;

    flp = netdev_priv(slave);

    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->master[i] == master)
            break;

    if (i == CONFIG_DLCI_MAX)
        return -ENODEV;

    flp->master[i] = NULL;
    flp->dlci[i] = 0;


    if (netif_running(slave)) {
        if (flp->config.station == FRAD_STATION_CPE)
            sdla_reconfig(slave);
        else
            sdla_cmd(slave, SDLA_DELETE_DLCI, 0, 0, master->dev_addr, sizeof(short), NULL, NULL);
    }

    return 0;
}

static int sdla_dlci_conf(struct net_device *slave, struct net_device *master, int get)
{
    struct frad_local *flp;
    struct dlci_local *dlp;
    int               i;
    short             len, ret;

    flp = netdev_priv(slave);

    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->master[i] == master)
            break;

    if (i == CONFIG_DLCI_MAX)
        return -ENODEV;

    dlp = netdev_priv(master);

    ret = SDLA_RET_OK;
    len = sizeof(struct dlci_conf);
    if (netif_running(slave)) {
        if (get)
            ret = sdla_cmd(slave, SDLA_READ_DLCI_CONFIGURATION, abs(flp->dlci[i]), 0,  
                        NULL, 0, &dlp->config, &len);
        else
            ret = sdla_cmd(slave, SDLA_SET_DLCI_CONFIGURATION, abs(flp->dlci[i]), 0,  
                        &dlp->config, sizeof(struct dlci_conf) - 4 * sizeof(short), NULL, NULL);
    }

    return ret == SDLA_RET_OK ? 0 : -EIO;
}

/**************************
 *
 * now for the Linux driver 
 *
 **************************/

/* NOTE: the DLCI driver deals with freeing the SKB!! */
static netdev_tx_t sdla_transmit(struct sk_buff *skb,
                 struct net_device *dev)
{
    struct frad_local *flp;
    int               ret, addr, accept, i;
    short             size;
    unsigned long     flags;
    struct buf_entry  *pbuf;

    flp = netdev_priv(dev);
    ret = 0;
    accept = 1;

    netif_stop_queue(dev);

    /*
     * stupid GateD insists on setting up the multicast router thru us
     * and we're ill equipped to handle a non Frame Relay packet at this
     * time!
     */

    accept = 1;
    switch (dev->type)
    {
        case ARPHRD_FRAD:
            if (skb->dev->type != ARPHRD_DLCI)
            {
                netdev_warn(dev, "Non DLCI device, type %i, tried to send on FRAD module\n",
                        skb->dev->type);
                accept = 0;
            }
            break;
        default:
            netdev_warn(dev, "unknown firmware type 0x%04X\n",
                    dev->type);
            accept = 0;
            break;
    }
    if (accept)
    {
        /* this is frame specific, but till there's a PPP module, it's the default */
        switch (flp->type)
        {
            case SDLA_S502A:
            case SDLA_S502E:
                ret = sdla_cmd(dev, SDLA_INFORMATION_WRITE, *(short *)(skb->dev->dev_addr), 0, skb->data, skb->len, NULL, NULL);
                break;
                case SDLA_S508:
                size = sizeof(addr);
                ret = sdla_cmd(dev, SDLA_INFORMATION_WRITE, *(short *)(skb->dev->dev_addr), 0, NULL, skb->len, &addr, &size);
                if (ret == SDLA_RET_OK)
                {

                    spin_lock_irqsave(&sdla_lock, flags);
                    SDLA_WINDOW(dev, addr);
                    pbuf = (void *)(((int) dev->mem_start) + (addr & SDLA_ADDR_MASK));
                    __sdla_write(dev, pbuf->buf_addr, skb->data, skb->len);
                    SDLA_WINDOW(dev, addr);
                    pbuf->opp_flag = 1;
                    spin_unlock_irqrestore(&sdla_lock, flags);
                }
                break;
        }

        switch (ret)
        {
            case SDLA_RET_OK:
                dev->stats.tx_packets++;
                break;

            case SDLA_RET_CIR_OVERFLOW:
            case SDLA_RET_BUF_OVERSIZE:
            case SDLA_RET_NO_BUFS:
                dev->stats.tx_dropped++;
                break;

            default:
                dev->stats.tx_errors++;
                break;
        }
    }
    netif_wake_queue(dev);
    for(i=0;i<CONFIG_DLCI_MAX;i++)
    {
        if(flp->master[i]!=NULL)
            netif_wake_queue(flp->master[i]);
    }       

    dev_kfree_skb(skb);
    return NETDEV_TX_OK;
}

static void sdla_receive(struct net_device *dev)
{
    struct net_device     *master;
    struct frad_local *flp;
    struct dlci_local *dlp;
    struct sk_buff   *skb;

    struct sdla_cmd *cmd;
    struct buf_info *pbufi;
    struct buf_entry  *pbuf;

    unsigned long     flags;
    int               i=0, received, success, addr, buf_base, buf_top;
    short             dlci, len, len2, split;

    flp = netdev_priv(dev);
    success = 1;
    received = addr = buf_top = buf_base = 0;
    len = dlci = 0;
    skb = NULL;
    master = NULL;
    cmd = NULL;
    pbufi = NULL;
    pbuf = NULL;

    spin_lock_irqsave(&sdla_lock, flags);

    switch (flp->type)
    {
        case SDLA_S502A:
        case SDLA_S502E:
            cmd = (void *) (dev->mem_start + (SDLA_502_RCV_BUF & SDLA_ADDR_MASK));
            SDLA_WINDOW(dev, SDLA_502_RCV_BUF);
            success = cmd->opp_flag;
            if (!success)
                break;

            dlci = cmd->dlci;
            len = cmd->length;
            break;

        case SDLA_S508:
            pbufi = (void *) (dev->mem_start + (SDLA_508_RXBUF_INFO & SDLA_ADDR_MASK));
            SDLA_WINDOW(dev, SDLA_508_RXBUF_INFO);
            pbuf = (void *) (dev->mem_start + ((pbufi->rse_base + flp->buffer * sizeof(struct buf_entry)) & SDLA_ADDR_MASK));
            success = pbuf->opp_flag;
            if (!success)
                break;

            buf_top = pbufi->buf_top;
            buf_base = pbufi->buf_base;
            dlci = pbuf->dlci;
            len = pbuf->length;
            addr = pbuf->buf_addr;
            break;
    }

    /* common code, find the DLCI and get the SKB */
    if (success)
    {
        for (i=0;i<CONFIG_DLCI_MAX;i++)
            if (flp->dlci[i] == dlci)
                break;

        if (i == CONFIG_DLCI_MAX)
        {
            netdev_notice(dev, "Received packet from invalid DLCI %i, ignoring\n",
                      dlci);
            dev->stats.rx_errors++;
            success = 0;
        }
    }

    if (success)
    {
        master = flp->master[i];
        skb = dev_alloc_skb(len + sizeof(struct frhdr));
        if (skb == NULL) 
        {
            netdev_notice(dev, "Memory squeeze, dropping packet\n");
            dev->stats.rx_dropped++;
            success = 0;
        }
        else
            skb_reserve(skb, sizeof(struct frhdr));
    }

    /* pick up the data */
    switch (flp->type)
    {
        case SDLA_S502A:
        case SDLA_S502E:
            if (success)
                __sdla_read(dev, SDLA_502_RCV_BUF + SDLA_502_DATA_OFS, skb_put(skb,len), len);

            SDLA_WINDOW(dev, SDLA_502_RCV_BUF);
            cmd->opp_flag = 0;
            break;

        case SDLA_S508:
            if (success)
            {
                /* is this buffer split off the end of the internal ring buffer */
                split = addr + len > buf_top + 1 ? len - (buf_top - addr + 1) : 0;
                len2 = len - split;

                __sdla_read(dev, addr, skb_put(skb, len2), len2);
                if (split)
                    __sdla_read(dev, buf_base, skb_put(skb, split), split);
            }

            /* increment the buffer we're looking at */
            SDLA_WINDOW(dev, SDLA_508_RXBUF_INFO);
            flp->buffer = (flp->buffer + 1) % pbufi->rse_num;
            pbuf->opp_flag = 0;
            break;
    }

    if (success)
    {
        dev->stats.rx_packets++;
        dlp = netdev_priv(master);
        (*dlp->receive)(skb, master);
    }

    spin_unlock_irqrestore(&sdla_lock, flags);
}

static irqreturn_t sdla_isr(int dummy, void *dev_id)
{
    struct net_device     *dev;
    struct frad_local *flp;
    char              byte;

    dev = dev_id;

    flp = netdev_priv(dev);

    if (!flp->initialized)
    {
        netdev_warn(dev, "irq %d for uninitialized device\n", dev->irq);
        return IRQ_NONE;
    }

    byte = sdla_byte(dev, flp->type == SDLA_S508 ? SDLA_508_IRQ_INTERFACE : SDLA_502_IRQ_INTERFACE);
    switch (byte)
    {
        case SDLA_INTR_RX:
            sdla_receive(dev);
            break;

        /* the command will get an error return, which is processed above */
        case SDLA_INTR_MODEM:
        case SDLA_INTR_STATUS:
            sdla_cmd(dev, SDLA_READ_DLC_STATUS, 0, 0, NULL, 0, NULL, NULL);
            break;

        case SDLA_INTR_TX:
        case SDLA_INTR_COMPLETE:
        case SDLA_INTR_TIMER:
            netdev_warn(dev, "invalid irq flag 0x%02X\n", byte);
            break;
    }

    /* the S502E requires a manual acknowledgement of the interrupt */ 
    if (flp->type == SDLA_S502E)
    {
        flp->state &= ~SDLA_S502E_INTACK;
        outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
        flp->state |= SDLA_S502E_INTACK;
        outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
    }

    /* this clears the byte, informing the Z80 we're done */
    byte = 0;
    sdla_write(dev, flp->type == SDLA_S508 ? SDLA_508_IRQ_INTERFACE : SDLA_502_IRQ_INTERFACE, &byte, sizeof(byte));
    return IRQ_HANDLED;
}

static void sdla_poll(unsigned long device)
{
    struct net_device     *dev;
    struct frad_local *flp;

    dev = (struct net_device *) device;
    flp = netdev_priv(dev);

    if (sdla_byte(dev, SDLA_502_RCV_BUF))
        sdla_receive(dev);

    flp->timer.expires = 1;
    add_timer(&flp->timer);
}

static int sdla_close(struct net_device *dev)
{
    struct frad_local *flp;
    struct intr_info  intr;
    int               len, i;
    short             dlcis[CONFIG_DLCI_MAX];

    flp = netdev_priv(dev);

    len = 0;
    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->dlci[i])
            dlcis[len++] = abs(flp->dlci[i]);
    len *= 2;

    if (flp->config.station == FRAD_STATION_NODE)
    {
        for(i=0;i<CONFIG_DLCI_MAX;i++)
            if (flp->dlci[i] > 0) 
                sdla_cmd(dev, SDLA_DEACTIVATE_DLCI, 0, 0, dlcis, len, NULL, NULL);
        sdla_cmd(dev, SDLA_DELETE_DLCI, 0, 0, &flp->dlci[i], sizeof(flp->dlci[i]), NULL, NULL);
    }

    memset(&intr, 0, sizeof(intr));
    /* let's start up the reception */
    switch(flp->type)
    {
        case SDLA_S502A:
            del_timer(&flp->timer); 
            break;

        case SDLA_S502E:
            sdla_cmd(dev, SDLA_SET_IRQ_TRIGGER, 0, 0, &intr, sizeof(char) + sizeof(short), NULL, NULL);
            flp->state &= ~SDLA_S502E_INTACK;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            break;

        case SDLA_S507:
            break;

        case SDLA_S508:
            sdla_cmd(dev, SDLA_SET_IRQ_TRIGGER, 0, 0, &intr, sizeof(struct intr_info), NULL, NULL);
            flp->state &= ~SDLA_S508_INTEN;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            break;
    }

    sdla_cmd(dev, SDLA_DISABLE_COMMUNICATIONS, 0, 0, NULL, 0, NULL, NULL);

    netif_stop_queue(dev);
    
    return 0;
}

struct conf_data {
    struct frad_conf config;
    short            dlci[CONFIG_DLCI_MAX];
};

static int sdla_open(struct net_device *dev)
{
    struct frad_local *flp;
    struct dlci_local *dlp;
    struct conf_data  data;
    struct intr_info  intr;
    int               len, i;
    char              byte;

    flp = netdev_priv(dev);

    if (!flp->initialized)
        return -EPERM;

    if (!flp->configured)
        return -EPERM;

    /* time to send in the configuration */
    len = 0;
    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->dlci[i])
            data.dlci[len++] = abs(flp->dlci[i]);
    len *= 2;

    memcpy(&data.config, &flp->config, sizeof(struct frad_conf));
    len += sizeof(struct frad_conf);

    sdla_cmd(dev, SDLA_DISABLE_COMMUNICATIONS, 0, 0, NULL, 0, NULL, NULL);
    sdla_cmd(dev, SDLA_SET_DLCI_CONFIGURATION, 0, 0, &data, len, NULL, NULL);

    if (flp->type == SDLA_S508)
        flp->buffer = 0;

    sdla_cmd(dev, SDLA_ENABLE_COMMUNICATIONS, 0, 0, NULL, 0, NULL, NULL);

    /* let's start up the reception */
    memset(&intr, 0, sizeof(intr));
    switch(flp->type)
    {
        case SDLA_S502A:
            flp->timer.expires = 1;
            add_timer(&flp->timer);
            break;

        case SDLA_S502E:
            flp->state |= SDLA_S502E_ENABLE;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            flp->state |= SDLA_S502E_INTACK;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            byte = 0;
            sdla_write(dev, SDLA_502_IRQ_INTERFACE, &byte, sizeof(byte));
            intr.flags = SDLA_INTR_RX | SDLA_INTR_STATUS | SDLA_INTR_MODEM;
            sdla_cmd(dev, SDLA_SET_IRQ_TRIGGER, 0, 0, &intr, sizeof(char) + sizeof(short), NULL, NULL);
            break;

        case SDLA_S507:
            break;

        case SDLA_S508:
            flp->state |= SDLA_S508_INTEN;
            outb(flp->state, dev->base_addr + SDLA_REG_CONTROL);
            byte = 0;
            sdla_write(dev, SDLA_508_IRQ_INTERFACE, &byte, sizeof(byte));
            intr.flags = SDLA_INTR_RX | SDLA_INTR_STATUS | SDLA_INTR_MODEM;
            intr.irq = dev->irq;
            sdla_cmd(dev, SDLA_SET_IRQ_TRIGGER, 0, 0, &intr, sizeof(struct intr_info), NULL, NULL);
            break;
    }

    if (flp->config.station == FRAD_STATION_CPE)
    {
        byte = SDLA_ICS_STATUS_ENQ;
        sdla_cmd(dev, SDLA_ISSUE_IN_CHANNEL_SIGNAL, 0, 0, &byte, sizeof(byte), NULL, NULL);
    }
    else
    {
        sdla_cmd(dev, SDLA_ADD_DLCI, 0, 0, data.dlci, len - sizeof(struct frad_conf), NULL, NULL);
        for(i=0;i<CONFIG_DLCI_MAX;i++)
            if (flp->dlci[i] > 0)
                sdla_cmd(dev, SDLA_ACTIVATE_DLCI, 0, 0, &flp->dlci[i], 2*sizeof(flp->dlci[i]), NULL, NULL);
    }

    /* configure any specific DLCI settings */
    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->dlci[i])
        {
            dlp = netdev_priv(flp->master[i]);
            if (dlp->configured)
                sdla_cmd(dev, SDLA_SET_DLCI_CONFIGURATION, abs(flp->dlci[i]), 0, &dlp->config, sizeof(struct dlci_conf), NULL, NULL);
        }

    netif_start_queue(dev);
    
    return 0;
}

static int sdla_config(struct net_device *dev, struct frad_conf __user *conf, int get)
{
    struct frad_local *flp;
    struct conf_data  data;
    int               i;
    short             size;

    if (dev->type == 0xFFFF)
        return -EUNATCH;

    flp = netdev_priv(dev);

    if (!get)
    {
        if (netif_running(dev))
            return -EBUSY;

        if(copy_from_user(&data.config, conf, sizeof(struct frad_conf)))
            return -EFAULT;

        if (data.config.station & ~FRAD_STATION_NODE)
            return -EINVAL;

        if (data.config.flags & ~FRAD_VALID_FLAGS)
            return -EINVAL;

        if ((data.config.kbaud < 0) || 
             ((data.config.kbaud > 128) && (flp->type != SDLA_S508)))
            return -EINVAL;

        if (data.config.clocking & ~(FRAD_CLOCK_INT | SDLA_S508_PORT_RS232))
            return -EINVAL;

        if ((data.config.mtu < 0) || (data.config.mtu > SDLA_MAX_MTU))
            return -EINVAL;

        if ((data.config.T391 < 5) || (data.config.T391 > 30))
            return -EINVAL;

        if ((data.config.T392 < 5) || (data.config.T392 > 30))
            return -EINVAL;

        if ((data.config.N391 < 1) || (data.config.N391 > 255))
            return -EINVAL;

        if ((data.config.N392 < 1) || (data.config.N392 > 10))
            return -EINVAL;

        if ((data.config.N393 < 1) || (data.config.N393 > 10))
            return -EINVAL;

        memcpy(&flp->config, &data.config, sizeof(struct frad_conf));
        flp->config.flags |= SDLA_DIRECT_RECV;

        if (flp->type == SDLA_S508)
            flp->config.flags |= SDLA_TX70_RX30;

        if (dev->mtu != flp->config.mtu)
        {
            /* this is required to change the MTU */
            dev->mtu = flp->config.mtu;
            for(i=0;i<CONFIG_DLCI_MAX;i++)
                if (flp->master[i])
                    flp->master[i]->mtu = flp->config.mtu;
        }

        flp->config.mtu += sizeof(struct frhdr);

        /* off to the races! */
        if (!flp->configured)
            sdla_start(dev);

        flp->configured = 1;
    }
    else
    {
        /* no sense reading if the CPU isn't started */
        if (netif_running(dev))
        {
            size = sizeof(data);
            if (sdla_cmd(dev, SDLA_READ_DLCI_CONFIGURATION, 0, 0, NULL, 0, &data, &size) != SDLA_RET_OK)
                return -EIO;
        }
        else
            if (flp->configured)
                memcpy(&data.config, &flp->config, sizeof(struct frad_conf));
            else
                memset(&data.config, 0, sizeof(struct frad_conf));

        memcpy(&flp->config, &data.config, sizeof(struct frad_conf));
        data.config.flags &= FRAD_VALID_FLAGS;
        data.config.mtu -= data.config.mtu > sizeof(struct frhdr) ? sizeof(struct frhdr) : data.config.mtu;
        return copy_to_user(conf, &data.config, sizeof(struct frad_conf))?-EFAULT:0;
    }

    return 0;
}

static int sdla_xfer(struct net_device *dev, struct sdla_mem __user *info, int read)
{
    struct sdla_mem mem;
    char    *temp;

    if(copy_from_user(&mem, info, sizeof(mem)))
        return -EFAULT;
        
    if (read)
    {   
        temp = kzalloc(mem.len, GFP_KERNEL);
        if (!temp)
            return -ENOMEM;
        sdla_read(dev, mem.addr, temp, mem.len);
        if(copy_to_user(mem.data, temp, mem.len))
        {
            kfree(temp);
            return -EFAULT;
        }
        kfree(temp);
    }
    else
    {
        temp = memdup_user(mem.data, mem.len);
        if (IS_ERR(temp))
            return PTR_ERR(temp);
        sdla_write(dev, mem.addr, temp, mem.len);
        kfree(temp);
    }
    return 0;
}

static int sdla_reconfig(struct net_device *dev)
{
    struct frad_local *flp;
    struct conf_data  data;
    int               i, len;

    flp = netdev_priv(dev);

    len = 0;
    for(i=0;i<CONFIG_DLCI_MAX;i++)
        if (flp->dlci[i])
            data.dlci[len++] = flp->dlci[i];
    len *= 2;

    memcpy(&data, &flp->config, sizeof(struct frad_conf));
    len += sizeof(struct frad_conf);

    sdla_cmd(dev, SDLA_DISABLE_COMMUNICATIONS, 0, 0, NULL, 0, NULL, NULL);
    sdla_cmd(dev, SDLA_SET_DLCI_CONFIGURATION, 0, 0, &data, len, NULL, NULL);
    sdla_cmd(dev, SDLA_ENABLE_COMMUNICATIONS, 0, 0, NULL, 0, NULL, NULL);

    return 0;
}

static int sdla_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
    struct frad_local *flp;

    if(!capable(CAP_NET_ADMIN))
        return -EPERM;
        
    flp = netdev_priv(dev);

    if (!flp->initialized)
        return -EINVAL;

    switch (cmd)
    {
        case FRAD_GET_CONF:
        case FRAD_SET_CONF:
            return sdla_config(dev, ifr->ifr_data, cmd == FRAD_GET_CONF);

        case SDLA_IDENTIFY:
            ifr->ifr_flags = flp->type;
            break;

        case SDLA_CPUSPEED:
            return sdla_cpuspeed(dev, ifr);

/* ==========================================================
NOTE:  This is rather a useless action right now, as the
       current driver does not support protocols other than
       FR.  However, Sangoma has modules for a number of
       other protocols in the works.
============================================================*/
        case SDLA_PROTOCOL:
            if (flp->configured)
                return -EALREADY;

            switch (ifr->ifr_flags)
            {
                case ARPHRD_FRAD:
                    dev->type = ifr->ifr_flags;
                    break;
                default:
                    return -ENOPROTOOPT;
            }
            break;

        case SDLA_CLEARMEM:
            sdla_clear(dev);
            break;

        case SDLA_WRITEMEM:
        case SDLA_READMEM:
            if(!capable(CAP_SYS_RAWIO))
                return -EPERM;
            return sdla_xfer(dev, ifr->ifr_data, cmd == SDLA_READMEM);

        case SDLA_START:
            sdla_start(dev);
            break;

        case SDLA_STOP:
            sdla_stop(dev);
            break;

        default:
            return -EOPNOTSUPP;
    }
    return 0;
}

static int sdla_change_mtu(struct net_device *dev, int new_mtu)
{
    struct frad_local *flp;

    flp = netdev_priv(dev);

    if (netif_running(dev))
        return -EBUSY;

    /* for now, you can't change the MTU! */
    return -EOPNOTSUPP;
}

static int sdla_set_config(struct net_device *dev, struct ifmap *map)
{
    struct frad_local *flp;
    int               i;
    char              byte;
    unsigned base;
    int err = -EINVAL;

    flp = netdev_priv(dev);

    if (flp->initialized)
        return -EINVAL;

    for(i=0; i < ARRAY_SIZE(valid_port); i++)
        if (valid_port[i] == map->base_addr)
            break;   

    if (i == ARRAY_SIZE(valid_port))
        return -EINVAL;

    if (!request_region(map->base_addr, SDLA_IO_EXTENTS, dev->name)){
        pr_warn("io-port 0x%04lx in use\n", dev->base_addr);
        return -EINVAL;
    }
    base = map->base_addr;

    /* test for card types, S502A, S502E, S507, S508                 */
    /* these tests shut down the card completely, so clear the state */
    flp->type = SDLA_UNKNOWN;
    flp->state = 0;
   
    for(i=1;i<SDLA_IO_EXTENTS;i++)
        if (inb(base + i) != 0xFF)
            break;

    if (i == SDLA_IO_EXTENTS) {   
        outb(SDLA_HALT, base + SDLA_REG_Z80_CONTROL);
        if ((inb(base + SDLA_S502_STS) & 0x0F) == 0x08) {
            outb(SDLA_S502E_INTACK, base + SDLA_REG_CONTROL);
            if ((inb(base + SDLA_S502_STS) & 0x0F) == 0x0C) {
                outb(SDLA_HALT, base + SDLA_REG_CONTROL);
                flp->type = SDLA_S502E;
                goto got_type;
            }
        }
    }

    for(byte=inb(base),i=0;i<SDLA_IO_EXTENTS;i++)
        if (inb(base + i) != byte)
            break;

    if (i == SDLA_IO_EXTENTS) {
        outb(SDLA_HALT, base + SDLA_REG_CONTROL);
        if ((inb(base + SDLA_S502_STS) & 0x7E) == 0x30) {
            outb(SDLA_S507_ENABLE, base + SDLA_REG_CONTROL);
            if ((inb(base + SDLA_S502_STS) & 0x7E) == 0x32) {
                outb(SDLA_HALT, base + SDLA_REG_CONTROL);
                flp->type = SDLA_S507;
                goto got_type;
            }
        }
    }

    outb(SDLA_HALT, base + SDLA_REG_CONTROL);
    if ((inb(base + SDLA_S508_STS) & 0x3F) == 0x00) {
        outb(SDLA_S508_INTEN, base + SDLA_REG_CONTROL);
        if ((inb(base + SDLA_S508_STS) & 0x3F) == 0x10) {
            outb(SDLA_HALT, base + SDLA_REG_CONTROL);
            flp->type = SDLA_S508;
            goto got_type;
        }
    }

    outb(SDLA_S502A_HALT, base + SDLA_REG_CONTROL);
    if (inb(base + SDLA_S502_STS) == 0x40) {
        outb(SDLA_S502A_START, base + SDLA_REG_CONTROL);
        if (inb(base + SDLA_S502_STS) == 0x40) {
            outb(SDLA_S502A_INTEN, base + SDLA_REG_CONTROL);
            if (inb(base + SDLA_S502_STS) == 0x44) {
                outb(SDLA_S502A_START, base + SDLA_REG_CONTROL);
                flp->type = SDLA_S502A;
                goto got_type;
            }
        }
    }

    netdev_notice(dev, "Unknown card type\n");
    err = -ENODEV;
    goto fail;

got_type:
    switch(base) {
        case 0x270:
        case 0x280:
        case 0x380: 
        case 0x390:
            if (flp->type != SDLA_S508 && flp->type != SDLA_S507)
                goto fail;
    }

    switch (map->irq) {
        case 2:
            if (flp->type != SDLA_S502E)
                goto fail;
            break;

        case 10:
        case 11:
        case 12:
        case 15:
        case 4:
            if (flp->type != SDLA_S508 && flp->type != SDLA_S507)
                goto fail;
            break;
        case 3:
        case 5:
        case 7:
            if (flp->type == SDLA_S502A)
                goto fail;
            break;

        default:
            goto fail;
    }

    err = -EAGAIN;
    if (request_irq(dev->irq, sdla_isr, 0, dev->name, dev)) 
        goto fail;

    if (flp->type == SDLA_S507) {
        switch(dev->irq) {
            case 3:
                flp->state = SDLA_S507_IRQ3;
                break;
            case 4:
                flp->state = SDLA_S507_IRQ4;
                break;
            case 5:
                flp->state = SDLA_S507_IRQ5;
                break;
            case 7:
                flp->state = SDLA_S507_IRQ7;
                break;
            case 10:
                flp->state = SDLA_S507_IRQ10;
                break;
            case 11:
                flp->state = SDLA_S507_IRQ11;
                break;
            case 12:
                flp->state = SDLA_S507_IRQ12;
                break;
            case 15:
                flp->state = SDLA_S507_IRQ15;
                break;
        }
    }

    for(i=0; i < ARRAY_SIZE(valid_mem); i++)
        if (valid_mem[i] == map->mem_start)
            break;   

    err = -EINVAL;
    if (i == ARRAY_SIZE(valid_mem))
        goto fail2;

    if (flp->type == SDLA_S502A && (map->mem_start & 0xF000) >> 12 == 0x0E)
        goto fail2;

    if (flp->type != SDLA_S507 && map->mem_start >> 16 == 0x0B)
        goto fail2;

    if (flp->type == SDLA_S507 && map->mem_start >> 16 == 0x0D)
        goto fail2;

    byte = flp->type != SDLA_S508 ? SDLA_8K_WINDOW : 0;
    byte |= (map->mem_start & 0xF000) >> (12 + (flp->type == SDLA_S508 ? 1 : 0));
    switch(flp->type) {
        case SDLA_S502A:
        case SDLA_S502E:
            switch (map->mem_start >> 16) {
                case 0x0A:
                    byte |= SDLA_S502_SEG_A;
                    break;
                case 0x0C:
                    byte |= SDLA_S502_SEG_C;
                    break;
                case 0x0D:
                    byte |= SDLA_S502_SEG_D;
                    break;
                case 0x0E:
                    byte |= SDLA_S502_SEG_E;
                    break;
            }
            break;
        case SDLA_S507:
            switch (map->mem_start >> 16) {
                case 0x0A:
                    byte |= SDLA_S507_SEG_A;
                    break;
                case 0x0B:
                    byte |= SDLA_S507_SEG_B;
                    break;
                case 0x0C:
                    byte |= SDLA_S507_SEG_C;
                    break;
                case 0x0E:
                    byte |= SDLA_S507_SEG_E;
                    break;
            }
            break;
        case SDLA_S508:
            switch (map->mem_start >> 16) {
                case 0x0A:
                    byte |= SDLA_S508_SEG_A;
                    break;
                case 0x0C:
                    byte |= SDLA_S508_SEG_C;
                    break;
                case 0x0D:
                    byte |= SDLA_S508_SEG_D;
                    break;
                case 0x0E:
                    byte |= SDLA_S508_SEG_E;
                    break;
            }
            break;
    }

    /* set the memory bits, and enable access */
    outb(byte, base + SDLA_REG_PC_WINDOW);

    switch(flp->type)
    {
        case SDLA_S502E:
            flp->state = SDLA_S502E_ENABLE;
            break;
        case SDLA_S507:
            flp->state |= SDLA_MEMEN;
            break;
        case SDLA_S508:
            flp->state = SDLA_MEMEN;
            break;
    }
    outb(flp->state, base + SDLA_REG_CONTROL);

    dev->irq = map->irq;
    dev->base_addr = base;
    dev->mem_start = map->mem_start;
    dev->mem_end = dev->mem_start + 0x2000;
    flp->initialized = 1;
    return 0;

fail2:
    free_irq(map->irq, dev);
fail:
    release_region(base, SDLA_IO_EXTENTS);
    return err;
}
 
static const struct net_device_ops sdla_netdev_ops = {
    .ndo_open   = sdla_open,
    .ndo_stop   = sdla_close,
    .ndo_do_ioctl   = sdla_ioctl,
    .ndo_set_config = sdla_set_config,
    .ndo_start_xmit = sdla_transmit,
    .ndo_change_mtu = sdla_change_mtu,
};

static void setup_sdla(struct net_device *dev)
{
    struct frad_local *flp = netdev_priv(dev);

    netdev_boot_setup_check(dev);

    dev->netdev_ops     = &sdla_netdev_ops;
    dev->flags      = 0;
    dev->type       = 0xFFFF;
    dev->hard_header_len    = 0;
    dev->addr_len       = 0;
    dev->mtu        = SDLA_MAX_MTU;

    flp->activate       = sdla_activate;
    flp->deactivate     = sdla_deactivate;
    flp->assoc      = sdla_assoc;
    flp->deassoc        = sdla_deassoc;
    flp->dlci_conf      = sdla_dlci_conf;

    init_timer(&flp->timer);
    flp->timer.expires  = 1;
    flp->timer.data     = (unsigned long) dev;
    flp->timer.function = sdla_poll;
}

static struct net_device *sdla;

static int __init init_sdla(void)
{
    int err;

    printk("%s.\n", version);

    sdla = alloc_netdev(sizeof(struct frad_local), "sdla0", setup_sdla);
    if (!sdla) 
        return -ENOMEM;

    err = register_netdev(sdla);
    if (err) 
        free_netdev(sdla);

    return err;
}

static void __exit exit_sdla(void)
{
    struct frad_local *flp = netdev_priv(sdla);

    unregister_netdev(sdla);
    if (flp->initialized) {
        free_irq(sdla->irq, sdla);
        release_region(sdla->base_addr, SDLA_IO_EXTENTS);
    }
    del_timer_sync(&flp->timer);
    free_netdev(sdla);
}

MODULE_LICENSE("GPL");

module_init(init_sdla);
module_exit(exit_sdla);