/*
 * USB Networking Links
 * Copyright (C) 2000-2003 by David Brownell <dbrownell@users.sourceforge.net>
 * Copyright (C) 2002 Pavel Machek <pavel@ucw.cz>
 * Copyright (C) 2003 David Hollis <dhollis@davehollis.com>
 * Copyright (c) 2002-2003 TiVo Inc.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*
 * This is a generic "USB networking" framework that works with several
 * kinds of full and high speed networking devices:
 *
 *   + USB host-to-host "network cables", used for IP-over-USB links.
 *     These are often used for Laplink style connectivity products.
 *      - AnchorChip 2720
 *      - Belkin, eTEK (interops with Win32 drivers)
 *      - GeneSys GL620USB-A
 *      - NetChip 1080 (interoperates with NetChip Win32 drivers)
 *      - Prolific PL-2301/2302 (replaces "plusb" driver)
 *      - KC Technology KC2190
 *
 *   + Smart USB devices can support such links directly, using Internet
 *     standard protocols instead of proprietary host-to-device links.
 *      - Linux PDAs like iPaq, Yopy, and Zaurus
 *      - The BLOB boot loader (for diskless booting)
 *      - Linux "gadgets", perhaps using PXA-2xx or Net2280 controllers
 *      - Devices using EPSON's sample USB firmware
 *      - CDC-Ethernet class devices, such as many cable modems
 *
 *   + Adapters to networks such as Ethernet.
 *      - AX8817X based USB 2.0 products
 *
 * Links to these devices can be bridged using Linux Ethernet bridging.
 * With minor exceptions, these all use similar USB framing for network
 * traffic, but need different protocols for control traffic.
 *
 * USB devices can implement their side of this protocol at the cost
 * of two bulk endpoints; it's not restricted to "cable" applications.
 * See the SA1110, Zaurus, or EPSON device/client support in this driver;
 * slave/target drivers such as "usb-eth" (on most SA-1100 PDAs) or
 * "g_ether" (in the Linux "gadget" framework) implement that behavior
 * within devices.
 *
 *
 * CHANGELOG:
 *
 * 13-sep-2000  experimental, new
 * 10-oct-2000  usb_device_id table created. 
 * 28-oct-2000  misc fixes; mostly, discard more TTL-mangled rx packets.
 * 01-nov-2000  usb_device_id table and probing api update by
 *              Adam J. Richter <adam@yggdrasil.com>.
 * 18-dec-2000  (db) tx watchdog, "net1080" renaming to "usbnet", device_info
 *              and prolific support, isolate net1080-specific bits, cleanup.
 *              fix unlink_urbs oops in D3 PM resume code path.
 *
 * 02-feb-2001  (db) fix tx skb sharing, packet length, match_flags, ...
 * 08-feb-2001  stubbed in "linuxdev", maybe the SA-1100 folk can use it;
 *              AnchorChips 2720 support (from spec) for testing;
 *              fix bit-ordering problem with ethernet multicast addr
 * 19-feb-2001  Support for clearing halt conditions. SA1100 UDC support
 *              updates. Oleg Drokin (green@iXcelerator.com)
 * 25-mar-2001  More SA-1100 updates, including workaround for ip problem
 *              expecting cleared skb->cb and framing change to match latest
 *              handhelds.org version (Oleg).  Enable device IDs from the
 *              Win32 Belkin driver; other cleanups (db).
 * 16-jul-2001  Bugfixes for uhci oops-on-unplug, Belkin support, various
 *              cleanups for problems not yet seen in the field. (db)
 * 17-oct-2001  Handle "Advance USBNET" product, like Belkin/eTEK devices,
 *              from Ioannis Mavroukakis <i.mavroukakis@btinternet.com>;
 *              rx unlinks somehow weren't async; minor cleanup.
 * 03-nov-2001  Merged GeneSys driver; original code from Jiun-Jie Huang
 *              <huangjj@genesyslogic.com.tw>, updated by Stanislav Brabec
 *              <utx@penguin.cz>.  Made framing options (NetChip/GeneSys)
 *              tie mostly to (sub)driver info.  Workaround some PL-2302
 *              chips that seem to reject SET_INTERFACE requests.
 *
 * 06-apr-2002  Added ethtool support, based on a patch from Brad Hards.
 *              Level of diagnostics is more configurable; they use device
 *              location (usb_device->devpath) instead of address (2.5).
 *              For tx_fixup, memflags can't be NOIO.
 * 07-may-2002  Generalize/cleanup keventd support, handling rx stalls (mostly
 *              for USB 2.0 TTs) and memory shortages (potential) too. (db)
 *              Use "locally assigned" IEEE802 address space. (Brad Hards)
 * 18-oct-2002  Support for Zaurus (Pavel Machek), related cleanup (db).
 * 14-dec-2002  Remove Zaurus-private crc32 code (Pavel); 2.5 oops fix,
 *              cleanups and stubbed PXA-250 support (db), fix for framing
 *              issues on Z, net1080, and gl620a (Toby Milne)
 *
 * 31-mar-2003  Use endpoint descriptors:  high speed support, simpler sa1100
 *              vs pxa25x, and CDC Ethernet.  Throttle down log floods on
 *              disconnect; other cleanups. (db)  Flush net1080 fifos
 *              after several sequential framing errors. (Johannes Erdfelt)
 * 22-aug-2003  AX8817X support (Dave Hollis).
 * 14-jun-2004  Trivial patch for AX8817X based Buffalo LUA-U2-KTX in Japan
 *              (Neil Bortnak)
 * 03-nov-2004  Trivial patch for KC2190 (KC-190) chip. (Jonathan McDowell)
 *
 *-------------------------------------------------------------------------*/

// #define      DEBUG                   // error path messages, extra info
// #define      VERBOSE                 // more; success messages

#include <linux/config.h>
#ifdef  CONFIG_USB_DEBUG
#   define DEBUG
#endif
#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/random.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
#include <linux/usb.h>
#include <asm/io.h>
#include <asm/scatterlist.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>

#define DRIVER_VERSION          "03-Nov-2004"


/*-------------------------------------------------------------------------*/

/*
 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
 * Several dozen bytes of IPv4 data can fit in two such transactions.
 * One maximum size Ethernet packet takes twenty four of them.
 * For high speed, each frame comfortably fits almost 36 max size
 * Ethernet packets (so queues should be bigger).
 */
#define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? 60 : 4)
#define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? 60 : 4)

// packets are always ethernet inside
// ... except they can be bigger (limit of 64K with NetChip framing)
#define MIN_PACKET      sizeof(struct ethhdr)
#define MAX_PACKET      32768

// reawaken network queue this soon after stopping; else watchdog barks
#define TX_TIMEOUT_JIFFIES      (5*HZ)

// throttle rx/tx briefly after some faults, so khubd might disconnect()
// us (it polls at HZ/4 usually) before we report too many false errors.
#define THROTTLE_JIFFIES        (HZ/8)

// for vendor-specific control operations
#define CONTROL_TIMEOUT_MS      (500)                   /* msec */
#define CONTROL_TIMEOUT_JIFFIES ((CONTROL_TIMEOUT_MS * HZ)/1000)

// between wakeups
#define UNLINK_TIMEOUT_MS       3

/*-------------------------------------------------------------------------*/

// randomly generated ethernet address
static u8       node_id [ETH_ALEN];

// state we keep for each device we handle
struct usbnet {
        // housekeeping
        struct usb_device       *udev;
        struct driver_info      *driver_info;
        wait_queue_head_t       *wait;

        // i/o info: pipes etc
        unsigned                in, out;
        unsigned                maxpacket;
        struct timer_list       delay;

        // protocol/interface state
        struct net_device       *net;
        struct net_device_stats stats;
        int                     msg_level;
        unsigned long           data [5];

        struct mii_if_info      mii;

        // various kinds of pending driver work
        struct sk_buff_head     rxq;
        struct sk_buff_head     txq;
        struct sk_buff_head     done;
        struct tasklet_struct   bh;

        struct work_struct      kevent;
        unsigned long           flags;
#               define EVENT_TX_HALT    0
#               define EVENT_RX_HALT    1
#               define EVENT_RX_MEMORY  2
};

// device-specific info used by the driver
struct driver_info {
        char            *description;

        int             flags;
/* framing is CDC Ethernet, not writing ZLPs (hw issues), or optionally: */
#define FLAG_FRAMING_NC 0x0001          /* guard against device dropouts */ 
#define FLAG_FRAMING_GL 0x0002          /* genelink batches packets */
#define FLAG_FRAMING_Z  0x0004          /* zaurus adds a trailer */
#define FLAG_FRAMING_RN 0x0008          /* RNDIS batches, plus huge header */

#define FLAG_NO_SETINT  0x0010          /* device can't set_interface() */
#define FLAG_ETHER      0x0020          /* maybe use "eth%d" names */

        /* init device ... can sleep, or cause probe() failure */
        int     (*bind)(struct usbnet *, struct usb_interface *);

        /* cleanup device ... can sleep, but can't fail */
        void    (*unbind)(struct usbnet *, struct usb_interface *);

        /* reset device ... can sleep */
        int     (*reset)(struct usbnet *);

        /* see if peer is connected ... can sleep */
        int     (*check_connect)(struct usbnet *);

        /* fixup rx packet (strip framing) */
        int     (*rx_fixup)(struct usbnet *dev, struct sk_buff *skb);

        /* fixup tx packet (add framing) */
        struct sk_buff  *(*tx_fixup)(struct usbnet *dev,
                                struct sk_buff *skb, int flags);

        // FIXME -- also an interrupt mechanism
        // useful for at least PL2301/2302 and GL620USB-A
        // and CDC use them to report 'is it connected' changes

        /* for new devices, use the descriptor-reading code instead */
        int             in;             /* rx endpoint */
        int             out;            /* tx endpoint */

        unsigned long   data;           /* Misc driver specific data */
};

// we record the state for each of our queued skbs
enum skb_state {
        illegal = 0,
        tx_start, tx_done,
        rx_start, rx_done, rx_cleanup
};

struct skb_data {       // skb->cb is one of these
        struct urb              *urb;
        struct usbnet           *dev;
        enum skb_state          state;
        size_t                  length;
};

static const char driver_name [] = "usbnet";

/* use ethtool to change the level for any given device */
static int msg_level = 1;
module_param (msg_level, int, 0);
MODULE_PARM_DESC (msg_level, "Initial message level (default = 1)");


#define RUN_CONTEXT (in_irq () ? "in_irq" \
                        : (in_interrupt () ? "in_interrupt" : "can sleep"))

#ifdef DEBUG
#define devdbg(usbnet, fmt, arg...) \
        printk(KERN_DEBUG "%s: " fmt "\n" , (usbnet)->net->name , ## arg)
#else
#define devdbg(usbnet, fmt, arg...) do {} while(0)
#endif

#define deverr(usbnet, fmt, arg...) \
        printk(KERN_ERR "%s: " fmt "\n" , (usbnet)->net->name , ## arg)
#define devwarn(usbnet, fmt, arg...) \
        printk(KERN_WARNING "%s: " fmt "\n" , (usbnet)->net->name , ## arg)

#define devinfo(usbnet, fmt, arg...) \
        do { if ((usbnet)->msg_level >= 1) \
        printk(KERN_INFO "%s: " fmt "\n" , (usbnet)->net->name , ## arg); \
        } while (0)

/*-------------------------------------------------------------------------*/

static void usbnet_get_drvinfo (struct net_device *, struct ethtool_drvinfo *);
static u32 usbnet_get_link (struct net_device *);
static u32 usbnet_get_msglevel (struct net_device *);
static void usbnet_set_msglevel (struct net_device *, u32);

/* mostly for PDA style devices, which are always connected if present */
static int always_connected (struct usbnet *dev)
{
        return 0;
}

/* handles CDC Ethernet and many other network "bulk data" interfaces */
static int
get_endpoints (struct usbnet *dev, struct usb_interface *intf)
{
        int                             tmp;
        struct usb_host_interface       *alt;
        struct usb_host_endpoint        *in, *out;

        for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
                unsigned        ep;

                in = out = NULL;
                alt = intf->altsetting + tmp;

                /* take the first altsetting with in-bulk + out-bulk;
                 * ignore other endpoints and altsetttings.
                 */
                for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
                        struct usb_host_endpoint        *e;

                        e = alt->endpoint + ep;
                        if (e->desc.bmAttributes != USB_ENDPOINT_XFER_BULK)
                                continue;
                        if (e->desc.bEndpointAddress & USB_DIR_IN) {
                                if (!in)
                                        in = e;
                        } else {
                                if (!out)
                                        out = e;
                        }
                        if (in && out)
                                goto found;
                }
        }
        return -EINVAL;

found:
        if (alt->desc.bAlternateSetting != 0
                        || !(dev->driver_info->flags & FLAG_NO_SETINT)) {
                tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
                                alt->desc.bAlternateSetting);
                if (tmp < 0)
                        return tmp;
        }
        
        dev->in = usb_rcvbulkpipe (dev->udev,
                        in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
        dev->out = usb_sndbulkpipe (dev->udev,
                        out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
        return 0;
}

static void skb_return (struct usbnet *dev, struct sk_buff *skb)
{
        int     status;

        skb->dev = dev->net;
        skb->protocol = eth_type_trans (skb, dev->net);
        dev->stats.rx_packets++;
        dev->stats.rx_bytes += skb->len;

#ifdef  VERBOSE
        devdbg (dev, "< rx, len %d, type 0x%x",
                skb->len + sizeof (struct ethhdr), skb->protocol);
#endif
        memset (skb->cb, 0, sizeof (struct skb_data));
        status = netif_rx (skb);
        if (status != NET_RX_SUCCESS)
                devdbg (dev, "netif_rx status %d", status);
}


#ifdef  CONFIG_USB_ALI_M5632
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * ALi M5632 driver ... does high speed
 *
 *-------------------------------------------------------------------------*/

static const struct driver_info ali_m5632_info = {
        .description =  "ALi M5632",
};


#endif


#ifdef  CONFIG_USB_AN2720
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * AnchorChips 2720 driver ... http://www.cypress.com
 *
 * This doesn't seem to have a way to detect whether the peer is
 * connected, or need any reset handshaking.  It's got pretty big
 * internal buffers (handles most of a frame's worth of data).
 * Chip data sheets don't describe any vendor control messages.
 *
 *-------------------------------------------------------------------------*/

static const struct driver_info an2720_info = {
        .description =  "AnchorChips/Cypress 2720",
        // no reset available!
        // no check_connect available!

        .in = 2, .out = 2,              // direction distinguishes these
};

#endif  /* CONFIG_USB_AN2720 */


#ifdef CONFIG_USB_AX8817X
/* ASIX AX8817X based USB 2.0 Ethernet Devices */

#define HAVE_HARDWARE
#define NEED_MII

#include <linux/crc32.h>

#define AX_CMD_SET_SW_MII               0x06
#define AX_CMD_READ_MII_REG             0x07
#define AX_CMD_WRITE_MII_REG            0x08
#define AX_CMD_SET_HW_MII               0x0a
#define AX_CMD_READ_EEPROM              0x0b
#define AX_CMD_WRITE_EEPROM             0x0c
#define AX_CMD_WRITE_RX_CTL             0x10
#define AX_CMD_READ_IPG012              0x11
#define AX_CMD_WRITE_IPG0               0x12
#define AX_CMD_WRITE_IPG1               0x13
#define AX_CMD_WRITE_IPG2               0x14
#define AX_CMD_WRITE_MULTI_FILTER       0x16
#define AX_CMD_READ_NODE_ID             0x17
#define AX_CMD_READ_PHY_ID              0x19
#define AX_CMD_WRITE_MEDIUM_MODE        0x1b
#define AX_CMD_READ_MONITOR_MODE        0x1c
#define AX_CMD_WRITE_MONITOR_MODE       0x1d
#define AX_CMD_WRITE_GPIOS              0x1f

#define AX_MONITOR_MODE                 0x01
#define AX_MONITOR_LINK                 0x02
#define AX_MONITOR_MAGIC                0x04
#define AX_MONITOR_HSFS                 0x10

#define AX_MCAST_FILTER_SIZE            8
#define AX_MAX_MCAST                    64

#define AX_INTERRUPT_BUFSIZE            8

/* This structure cannot exceed sizeof(unsigned long [5]) AKA 20 bytes */
struct ax8817x_data {
        u8 multi_filter[AX_MCAST_FILTER_SIZE];
        struct urb *int_urb;
        u8 *int_buf;
};

static int ax8817x_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
                            u16 size, void *data)
{
        return usb_control_msg(
                dev->udev,
                usb_rcvctrlpipe(dev->udev, 0),
                cmd,
                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                value,
                index,
                data,
                size,
                CONTROL_TIMEOUT_JIFFIES);
}

static int ax8817x_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
                             u16 size, void *data)
{
        return usb_control_msg(
                dev->udev,
                usb_sndctrlpipe(dev->udev, 0),
                cmd,
                USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                value,
                index,
                data,
                size,
                CONTROL_TIMEOUT_JIFFIES);
}

static void ax8817x_async_cmd_callback(struct urb *urb, struct pt_regs *regs)
{
        struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;

        if (urb->status < 0)
                printk(KERN_DEBUG "ax8817x_async_cmd_callback() failed with %d",
                        urb->status);

        kfree(req);
        usb_free_urb(urb);
}

static void ax8817x_interrupt_complete(struct urb *urb, struct pt_regs *regs)
{
        struct usbnet *dev = (struct usbnet *)urb->context;
        struct ax8817x_data *data = (struct ax8817x_data *)&dev->data;
        int link;

        if (urb->status < 0) {
                printk(KERN_DEBUG "ax8817x_interrupt_complete() failed with %d",
                        urb->status);
        } else {
                if (data->int_buf[5] == 0x90) {
                        link = data->int_buf[2] & 0x01;
                        if (netif_carrier_ok(dev->net) != link) {
                                if (link)
                                        netif_carrier_on(dev->net);
                                else
                                        netif_carrier_off(dev->net);
                                devdbg(dev, "ax8817x - Link Status is: %d", link);
                        }
                }
                usb_submit_urb(data->int_urb, GFP_ATOMIC);
        }
}

static void ax8817x_write_cmd_async(struct usbnet *dev, u8 cmd, u16 value, u16 index,
                                    u16 size, void *data)
{
        struct usb_ctrlrequest *req;
        int status;
        struct urb *urb;

        if ((urb = usb_alloc_urb(0, GFP_ATOMIC)) == NULL) {
                devdbg(dev, "Error allocating URB in write_cmd_async!");
                return;
        }

        if ((req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC)) == NULL) {
                deverr(dev, "Failed to allocate memory for control request");
                usb_free_urb(urb);
                return;
        }

        req->bRequestType = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
        req->bRequest = cmd;
        req->wValue = cpu_to_le16(value);
        req->wIndex = cpu_to_le16(index); 
        req->wLength = cpu_to_le16(size);

        usb_fill_control_urb(urb, dev->udev,
                             usb_sndctrlpipe(dev->udev, 0),
                             (void *)req, data, size,
                             ax8817x_async_cmd_callback, req);

        if((status = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
                deverr(dev, "Error submitting the control message: status=%d", status);
                kfree(req);
                usb_free_urb(urb);
        }
}

static void ax8817x_set_multicast(struct net_device *net)
{
        struct usbnet *dev = netdev_priv(net);
        struct ax8817x_data *data = (struct ax8817x_data *)&dev->data;
        u8 rx_ctl = 0x8c;

        if (net->flags & IFF_PROMISC) {
                rx_ctl |= 0x01;
        } else if (net->flags & IFF_ALLMULTI
                   || net->mc_count > AX_MAX_MCAST) {
                rx_ctl |= 0x02;
        } else if (net->mc_count == 0) {
                /* just broadcast and directed */
        } else {
                /* We use the 20 byte dev->data
                 * for our 8 byte filter buffer
                 * to avoid allocating memory that
                 * is tricky to free later */
                struct dev_mc_list *mc_list = net->mc_list;
                u32 crc_bits;
                int i;

                memset(data->multi_filter, 0, AX_MCAST_FILTER_SIZE);

                /* Build the multicast hash filter. */
                for (i = 0; i < net->mc_count; i++) {
                        crc_bits =
                            ether_crc(ETH_ALEN,
                                      mc_list->dmi_addr) >> 26;
                        data->multi_filter[crc_bits >> 3] |=
                            1 << (crc_bits & 7);
                        mc_list = mc_list->next;
                }

                ax8817x_write_cmd_async(dev, AX_CMD_WRITE_MULTI_FILTER, 0, 0,
                                   AX_MCAST_FILTER_SIZE, data->multi_filter);

                rx_ctl |= 0x10;
        }

        ax8817x_write_cmd_async(dev, AX_CMD_WRITE_RX_CTL, rx_ctl, 0, 0, NULL);
}

static int ax8817x_mdio_read(struct net_device *netdev, int phy_id, int loc)
{
        struct usbnet *dev = netdev_priv(netdev);
        u16 res;
        u8 buf[1];

        ax8817x_write_cmd(dev, AX_CMD_SET_SW_MII, 0, 0, 0, &buf);
        ax8817x_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id, (__u16)loc, 2, (u16 *)&res);
        ax8817x_write_cmd(dev, AX_CMD_SET_HW_MII, 0, 0, 0, &buf);

        return res & 0xffff;
}

static void ax8817x_mdio_write(struct net_device *netdev, int phy_id, int loc, int val)
{
        struct usbnet *dev = netdev_priv(netdev);
        u16 res = val;
        u8 buf[1];

        ax8817x_write_cmd(dev, AX_CMD_SET_SW_MII, 0, 0, 0, &buf);
        ax8817x_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id, (__u16)loc, 2, (u16 *)&res);
        ax8817x_write_cmd(dev, AX_CMD_SET_HW_MII, 0, 0, 0, &buf);
}

static void ax8817x_get_wol(struct net_device *net, struct ethtool_wolinfo *wolinfo)
{
        struct usbnet *dev = netdev_priv(net);
        u8 opt;

        if (ax8817x_read_cmd(dev, AX_CMD_READ_MONITOR_MODE, 0, 0, 1, &opt) < 0) {
                wolinfo->supported = 0;
                wolinfo->wolopts = 0;
                return;
        }
        wolinfo->supported = WAKE_PHY | WAKE_MAGIC;
        wolinfo->wolopts = 0;
        if (opt & AX_MONITOR_MODE) {
                if (opt & AX_MONITOR_LINK)
                        wolinfo->wolopts |= WAKE_PHY;
                if (opt & AX_MONITOR_MAGIC)
                        wolinfo->wolopts |= WAKE_MAGIC;
        }
}

static int ax8817x_set_wol(struct net_device *net, struct ethtool_wolinfo *wolinfo)
{
        struct usbnet *dev = netdev_priv(net);
        u8 opt = 0;
        u8 buf[1];

        if (wolinfo->wolopts & WAKE_PHY)
                opt |= AX_MONITOR_LINK;
        if (wolinfo->wolopts & WAKE_MAGIC)
                opt |= AX_MONITOR_MAGIC;
        if (opt != 0)
                opt |= AX_MONITOR_MODE;

        if (ax8817x_write_cmd(dev, AX_CMD_WRITE_MONITOR_MODE,
                              opt, 0, 0, &buf) < 0)
                return -EINVAL;

        return 0;
}

static int ax8817x_get_eeprom(struct net_device *net,
                              struct ethtool_eeprom *eeprom, u8 *data)
{
        struct usbnet *dev = netdev_priv(net);
        u16 *ebuf = (u16 *)data;
        int i;

        /* Crude hack to ensure that we don't overwrite memory
         * if an odd length is supplied
         */
        if (eeprom->len % 2)
                return -EINVAL;

        /* ax8817x returns 2 bytes from eeprom on read */
        for (i=0; i < eeprom->len / 2; i++) {
                if (ax8817x_read_cmd(dev, AX_CMD_READ_EEPROM, 
                        eeprom->offset + i, 0, 2, &ebuf[i]) < 0)
                        return -EINVAL;
        }
        return i * 2;
}

static void ax8817x_get_drvinfo (struct net_device *net,
                                 struct ethtool_drvinfo *info)
{
        /* Inherit standard device info */
        usbnet_get_drvinfo(net, info);
        info->eedump_len = 0x3e;
}

static int ax8817x_get_settings(struct net_device *net, struct ethtool_cmd *cmd)
{
        struct usbnet *dev = netdev_priv(net);

        return mii_ethtool_gset(&dev->mii,cmd);
}

static int ax8817x_set_settings(struct net_device *net, struct ethtool_cmd *cmd)
{
        struct usbnet *dev = netdev_priv(net);

        return mii_ethtool_sset(&dev->mii,cmd);
}

/* We need to override some ethtool_ops so we require our
   own structure so we don't interfere with other usbnet
   devices that may be connected at the same time. */
static struct ethtool_ops ax8817x_ethtool_ops = {
        .get_drvinfo            = ax8817x_get_drvinfo,
        .get_link               = ethtool_op_get_link,
        .get_msglevel           = usbnet_get_msglevel,
        .set_msglevel           = usbnet_set_msglevel,
        .get_wol                = ax8817x_get_wol,
        .set_wol                = ax8817x_set_wol,
        .get_eeprom             = ax8817x_get_eeprom,
        .get_settings           = ax8817x_get_settings,
        .set_settings           = ax8817x_set_settings,
};

static int ax8817x_bind(struct usbnet *dev, struct usb_interface *intf)
{
        int ret;
        u8 buf[6];
        int i;
        unsigned long gpio_bits = dev->driver_info->data;
        struct ax8817x_data *data = (struct ax8817x_data *)dev->data;

        dev->in = usb_rcvbulkpipe(dev->udev, 3);
        dev->out = usb_sndbulkpipe(dev->udev, 2);

        // allocate irq urb
        if ((data->int_urb = usb_alloc_urb (0, GFP_KERNEL)) == NULL) {
                dbg ("%s: cannot allocate interrupt URB",
                        dev->net->name);
                return -ENOMEM;
        }
        
        if ((data->int_buf = kmalloc(AX_INTERRUPT_BUFSIZE, GFP_KERNEL)) == NULL) {
                dbg ("%s: cannot allocate memory for interrupt buffer",
                        dev->net->name);
                usb_free_urb(data->int_urb);
                return -ENOMEM;
        }
        memset(data->int_buf, 0, AX_INTERRUPT_BUFSIZE);

        usb_fill_int_urb (data->int_urb, dev->udev,
                usb_rcvintpipe (dev->udev, 1),
                data->int_buf, AX_INTERRUPT_BUFSIZE,
                ax8817x_interrupt_complete, dev,
                dev->udev->speed == USB_SPEED_HIGH ? 8 : 100);

        /* Toggle the GPIOs in a manufacturer/model specific way */
        for (i = 2; i >= 0; i--) {
                if ((ret = ax8817x_write_cmd(dev, AX_CMD_WRITE_GPIOS,
                                        (gpio_bits >> (i * 8)) & 0xff, 0, 0,
                                        buf)) < 0)
                        return ret;
                msleep(5);
        }

        if ((ret = ax8817x_write_cmd(dev, AX_CMD_WRITE_RX_CTL, 0x80, 0, 0, buf)) < 0) {
                dbg("send AX_CMD_WRITE_RX_CTL failed: %d", ret);
                return ret;
        }

        /* Get the MAC address */
        memset(buf, 0, ETH_ALEN);
        if ((ret = ax8817x_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, 6, buf)) < 0) {
                dbg("read AX_CMD_READ_NODE_ID failed: %d", ret);
                return ret;
        }
        memcpy(dev->net->dev_addr, buf, ETH_ALEN);

        /* Get the PHY id */
        if ((ret = ax8817x_read_cmd(dev, AX_CMD_READ_PHY_ID, 0, 0, 2, buf)) < 0) {
                dbg("error on read AX_CMD_READ_PHY_ID: %02x", ret);
                return ret;
        } else if (ret < 2) {
                /* this should always return 2 bytes */
                dbg("AX_CMD_READ_PHY_ID returned less than 2 bytes: ret=%02x", ret);
                return -EIO;
        }

        /* Initialize MII structure */
        dev->mii.dev = dev->net;
        dev->mii.mdio_read = ax8817x_mdio_read;
        dev->mii.mdio_write = ax8817x_mdio_write;
        dev->mii.phy_id_mask = 0x3f;
        dev->mii.reg_num_mask = 0x1f;
        dev->mii.phy_id = buf[1];

        dev->net->set_multicast_list = ax8817x_set_multicast;
        dev->net->ethtool_ops = &ax8817x_ethtool_ops;

        ax8817x_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR,
                        cpu_to_le16(BMCR_RESET));
        ax8817x_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,
                        cpu_to_le16(ADVERTISE_ALL | ADVERTISE_CSMA | 0x0400));
        mii_nway_restart(&dev->mii);

        if((ret = usb_submit_urb(data->int_urb, GFP_KERNEL)) < 0) {
                dbg("Failed to submit interrupt URB: %02x", ret);
                usb_free_urb(data->int_urb);
                return ret;
        }

        return 0;
}

static void ax8817x_unbind(struct usbnet *dev, struct usb_interface *intf)
{
        struct ax8817x_data *data = (struct ax8817x_data *)dev->data;

        usb_kill_urb(data->int_urb);
        usb_free_urb(data->int_urb);
        kfree(data->int_buf);
}

static const struct driver_info ax8817x_info = {
        .description = "ASIX AX8817x USB 2.0 Ethernet",
        .bind = ax8817x_bind,
        .unbind = ax8817x_unbind,
        .flags =  FLAG_ETHER,
        .data = 0x00130103,
};

static const struct driver_info dlink_dub_e100_info = {
        .description = "DLink DUB-E100 USB Ethernet",
        .bind = ax8817x_bind,
        .unbind = ax8817x_unbind,
        .flags =  FLAG_ETHER,
        .data = 0x009f9d9f,
};

static const struct driver_info netgear_fa120_info = {
        .description = "Netgear FA-120 USB Ethernet",
        .bind = ax8817x_bind,
        .unbind = ax8817x_unbind,
        .flags =  FLAG_ETHER,
        .data = 0x00130103,
};

static const struct driver_info hawking_uf200_info = {
        .description = "Hawking UF200 USB Ethernet",
        .bind = ax8817x_bind,
        .unbind = ax8817x_unbind,
        .flags =  FLAG_ETHER,
        .data = 0x001f1d1f,
};

#endif /* CONFIG_USB_AX8817X */



#ifdef  CONFIG_USB_BELKIN
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * Belkin F5U104 ... two NetChip 2280 devices + Atmel microcontroller
 *
 * ... also two eTEK designs, including one sold as "Advance USBNET"
 *
 *-------------------------------------------------------------------------*/

static const struct driver_info belkin_info = {
        .description =  "Belkin, eTEK, or compatible",
};

#endif  /* CONFIG_USB_BELKIN */



/*-------------------------------------------------------------------------
 *
 * Communications Device Class declarations.
 * Used by CDC Ethernet, and some CDC variants
 *
 *-------------------------------------------------------------------------*/

#ifdef  CONFIG_USB_CDCETHER
#define NEED_GENERIC_CDC
#endif

#ifdef  CONFIG_USB_ZAURUS
/* Ethernet variant uses funky framing, broken ethernet addressing */
#define NEED_GENERIC_CDC
#endif

#ifdef  CONFIG_USB_RNDIS
/* ACM variant uses even funkier framing, complex control RPC scheme */
#define NEED_GENERIC_CDC
#endif


#ifdef  NEED_GENERIC_CDC

/* "Header Functional Descriptor" from CDC spec  5.2.3.1 */
struct header_desc {
        u8      bLength;
        u8      bDescriptorType;
        u8      bDescriptorSubType;

        u16     bcdCDC;
} __attribute__ ((packed));

/* "Union Functional Descriptor" from CDC spec 5.2.3.X */
struct union_desc {
        u8      bLength;
        u8      bDescriptorType;
        u8      bDescriptorSubType;

        u8      bMasterInterface0;
        u8      bSlaveInterface0;
        /* ... and there could be other slave interfaces */
} __attribute__ ((packed));

/* "Ethernet Networking Functional Descriptor" from CDC spec 5.2.3.16 */
struct ether_desc {
        u8      bLength;
        u8      bDescriptorType;
        u8      bDescriptorSubType;

        u8      iMACAddress;
        u32     bmEthernetStatistics;
        __le16  wMaxSegmentSize;
        __le16  wNumberMCFilters;
        u8      bNumberPowerFilters;
} __attribute__ ((packed));

struct cdc_state {
        struct header_desc      *header;
        struct union_desc       *u;
        struct ether_desc       *ether;
        struct usb_interface    *control;
        struct usb_interface    *data;
};

static struct usb_driver usbnet_driver;

/*
 * probes control interface, claims data interface, collects the bulk
 * endpoints, activates data interface (if needed), maybe sets MTU.
 * all pure cdc, except for certain firmware workarounds.
 */
static int generic_cdc_bind (struct usbnet *dev, struct usb_interface *intf)
{
        u8                              *buf = intf->cur_altsetting->extra;
        int                             len = intf->cur_altsetting->extralen;
        struct usb_interface_descriptor *d;
        struct cdc_state                *info = (void *) &dev->data;
        int                             status;
        int                             rndis;

        if (sizeof dev->data < sizeof *info)
                return -EDOM;

        /* expect strict spec conformance for the descriptors, but
         * cope with firmware which stores them in the wrong place
         */
        if (len == 0 && dev->udev->actconfig->extralen) {
                /* Motorola SB4100 (and others: Brad Hards says it's
                 * from a Broadcom design) put CDC descriptors here
                 */
                buf = dev->udev->actconfig->extra;
                len = dev->udev->actconfig->extralen;
                if (len)
                        dev_dbg (&intf->dev,
                                "CDC descriptors on config\n");
        }

        /* this assumes that if there's a non-RNDIS vendor variant
         * of cdc-acm, it'll fail RNDIS requests cleanly.
         */
        rndis = (intf->cur_altsetting->desc.bInterfaceProtocol == 0xff);

        memset (info, 0, sizeof *info);
        info->control = intf;
        while (len > 3) {
                if (buf [1] != USB_DT_CS_INTERFACE)
                        goto next_desc;

                /* use bDescriptorSubType to identify the CDC descriptors.
                 * We expect devices with CDC header and union descriptors.

                 * For CDC Ethernet we need the ethernet descriptor.
                 * For RNDIS, ignore two (pointless) CDC modem descriptors
                 * in favor of a complicated OID-based RPC scheme doing what
                 * CDC Ethernet achieves with a simple descriptor.
                 */
                switch (buf [2]) {
                case 0x00:              /* Header, mostly useless */
                        if (info->header) {
                                dev_dbg (&intf->dev, "extra CDC header\n");
                                goto bad_desc;
                        }
                        info->header = (void *) buf;
                        if (info->header->bLength != sizeof *info->header) {
                                dev_dbg (&intf->dev, "CDC header len %u\n",
                                        info->header->bLength);
                                goto bad_desc;
                        }
                        break;
                case 0x06:              /* Union (groups interfaces) */
                        if (info->u) {
                                dev_dbg (&intf->dev, "extra CDC union\n");
                                goto bad_desc;
                        }
                        info->u = (void *) buf;
                        if (info->u->bLength != sizeof *info->u) {
                                dev_dbg (&intf->dev, "CDC union len %u\n",
                                        info->u->bLength);
                                goto bad_desc;
                        }

                        /* we need a master/control interface (what we're
                         * probed with) and a slave/data interface; union
                         * descriptors sort this all out.
                         */
                        info->control = usb_ifnum_to_if(dev->udev,
                                                info->u->bMasterInterface0);
                        info->data = usb_ifnum_to_if(dev->udev,
                                                info->u->bSlaveInterface0);
                        if (!info->control || !info->data) {
                                dev_dbg (&intf->dev,
                                        "master #%u/%p slave #%u/%p\n",
                                        info->u->bMasterInterface0,
                                        info->control,
                                        info->u->bSlaveInterface0,
                                        info->data);
                                goto bad_desc;
                        }
                        if (info->control != intf) {
                                dev_dbg (&intf->dev, "bogus CDC Union\n");
                                /* Ambit USB Cable Modem (and maybe others)
                                 * interchanges master and slave interface.
                                 */
                                if (info->data == intf) {
                                        info->data = info->control;
                                        info->control = intf;
                                } else
                                        goto bad_desc;
                        }

                        /* a data interface altsetting does the real i/o */
                        d = &info->data->cur_altsetting->desc;
                        if (d->bInterfaceClass != USB_CLASS_CDC_DATA) {
                                dev_dbg (&intf->dev, "slave class %u\n",
                                        d->bInterfaceClass);
                                goto bad_desc;
                        }
                        break;
                case 0x0F:              /* Ethernet Networking */
                        if (info->ether) {
                                dev_dbg (&intf->dev, "extra CDC ether\n");
                                goto bad_desc;
                        }
                        info->ether = (void *) buf;
                        if (info->ether->bLength != sizeof *info->ether) {
                                dev_dbg (&intf->dev, "CDC ether len %u\n",
                                        info->u->bLength);
                                goto bad_desc;
                        }
                        dev->net->mtu = le16_to_cpup (
                                                &info->ether->wMaxSegmentSize)
                                        - ETH_HLEN;
                        /* because of Zaurus, we may be ignoring the host
                         * side link address we were given.
                         */
                        break;
                }
next_desc:
                len -= buf [0]; /* bLength */
                buf += buf [0];
        }

        if (!info->header || !info->u || (!rndis && !info->ether)) {
                dev_dbg (&intf->dev, "missing cdc %s%s%sdescriptor\n",
                        info->header ? "" : "header ",
                        info->u ? "" : "union ",
                        info->ether ? "" : "ether ");
                goto bad_desc;
        }

        /* claim data interface and set it up ... with side effects.
         * network traffic can't flow until an altsetting is enabled.
         */
        status = usb_driver_claim_interface (&usbnet_driver, info->data, dev);
        if (status < 0)
                return status;
        status = get_endpoints (dev, info->data);
        if (status < 0) {
                /* ensure immediate exit from usbnet_disconnect */
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface (&usbnet_driver, info->data);
                return status;
        }
        return 0;

bad_desc:
        dev_info (&dev->udev->dev, "bad CDC descriptors\n");
        return -ENODEV;
}

static void cdc_unbind (struct usbnet *dev, struct usb_interface *intf)
{
        struct cdc_state                *info = (void *) &dev->data;

        /* disconnect master --> disconnect slave */
        if (intf == info->control && info->data) {
                /* ensure immediate exit from usbnet_disconnect */
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface (&usbnet_driver, info->data);
                info->data = NULL;
        }

        /* and vice versa (just in case) */
        else if (intf == info->data && info->control) {
                /* ensure immediate exit from usbnet_disconnect */
                usb_set_intfdata(info->control, NULL);
                usb_driver_release_interface (&usbnet_driver, info->control);
                info->control = NULL;
        }
}

#endif  /* NEED_GENERIC_CDC */


#ifdef  CONFIG_USB_CDCETHER
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * Communications Device Class, Ethernet Control model
 * 
 * Takes two interfaces.  The DATA interface is inactive till an altsetting
 * is selected.  Configuration data includes class descriptors.
 *
 * This should interop with whatever the 2.4 "CDCEther.c" driver
 * (by Brad Hards) talked with.
 *
 *-------------------------------------------------------------------------*/

#include <linux/ctype.h>

static u8 nibble (unsigned char c)
{
        if (likely (isdigit (c)))
                return c - '0';
        c = toupper (c);
        if (likely (isxdigit (c)))
                return 10 + c - 'A';
        return 0;
}

static inline int
get_ethernet_addr (struct usbnet *dev, struct ether_desc *e)
{
        int             tmp, i;
        unsigned char   buf [13];

        tmp = usb_string (dev->udev, e->iMACAddress, buf, sizeof buf);
        if (tmp != 12) {
                dev_dbg (&dev->udev->dev,
                        "bad MAC string %d fetch, %d\n", e->iMACAddress, tmp);
                if (tmp >= 0)
                        tmp = -EINVAL;
                return tmp;
        }
        for (i = tmp = 0; i < 6; i++, tmp += 2)
                dev->net->dev_addr [i] =
                         (nibble (buf [tmp]) << 4) + nibble (buf [tmp + 1]);
        return 0;
}

static int cdc_bind (struct usbnet *dev, struct usb_interface *intf)
{
        int                             status;
        struct cdc_state                *info = (void *) &dev->data;

        status = generic_cdc_bind (dev, intf);
        if (status < 0)
                return status;

        status = get_ethernet_addr (dev, info->ether);
        if (status < 0) {
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface (&usbnet_driver, info->data);
                return status;
        }

        /* FIXME cdc-ether has some multicast code too, though it complains
         * in routine cases.  info->ether describes the multicast support.
         */
        return 0;
}

static const struct driver_info cdc_info = {
        .description =  "CDC Ethernet Device",
        .flags =        FLAG_ETHER,
        // .check_connect = cdc_check_connect,
        .bind =         cdc_bind,
        .unbind =       cdc_unbind,
};

#endif  /* CONFIG_USB_CDCETHER */



#ifdef  CONFIG_USB_EPSON2888
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * EPSON USB clients
 *
 * This is the same idea as Linux PDAs (below) except the firmware in the
 * device might not be Tux-powered.  Epson provides reference firmware that
 * implements this interface.  Product developers can reuse or modify that
 * code, such as by using their own product and vendor codes.
 *
 * Support was from Juro Bystricky <bystricky.juro@erd.epson.com>
 *
 *-------------------------------------------------------------------------*/

static const struct driver_info epson2888_info = {
        .description =  "Epson USB Device",
        .check_connect = always_connected,

        .in = 4, .out = 3,
};

#endif  /* CONFIG_USB_EPSON2888 */


#ifdef CONFIG_USB_GENESYS
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * GeneSys GL620USB-A (www.genesyslogic.com.tw)
 *
 * ... should partially interop with the Win32 driver for this hardware
 * The GeneSys docs imply there's some NDIS issue motivating this framing.
 *
 * Some info from GeneSys:
 *  - GL620USB-A is full duplex; GL620USB is only half duplex for bulk.
 *    (Some cables, like the BAFO-100c, use the half duplex version.)
 *  - For the full duplex model, the low bit of the version code says
 *    which side is which ("left/right").
 *  - For the half duplex type, a control/interrupt handshake settles
 *    the transfer direction.  (That's disabled here, partially coded.)
 *    A control URB would block until other side writes an interrupt.
 *
 * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
 * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>.
 *
 *-------------------------------------------------------------------------*/

// control msg write command
#define GENELINK_CONNECT_WRITE                  0xF0
// interrupt pipe index
#define GENELINK_INTERRUPT_PIPE                 0x03
// interrupt read buffer size
#define INTERRUPT_BUFSIZE                       0x08
// interrupt pipe interval value
#define GENELINK_INTERRUPT_INTERVAL             0x10
// max transmit packet number per transmit
#define GL_MAX_TRANSMIT_PACKETS                 32
// max packet length
#define GL_MAX_PACKET_LEN                       1514
// max receive buffer size 
#define GL_RCV_BUF_SIZE         \
        (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)

struct gl_packet {
        u32             packet_length;
        char            packet_data [1];
};

struct gl_header {
        u32                     packet_count;
        struct gl_packet        packets;
};

#ifdef  GENELINK_ACK

// FIXME:  this code is incomplete, not debugged; it doesn't
// handle interrupts correctly.  interrupts should be generic
// code like all other device I/O, anyway.

struct gl_priv { 
        struct urb      *irq_urb;
        char            irq_buf [INTERRUPT_BUFSIZE];
};

static inline int gl_control_write (struct usbnet *dev, u8 request, u16 value)
{
        int retval;

        retval = usb_control_msg (dev->udev,
                      usb_sndctrlpipe (dev->udev, 0),
                      request,
                      USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
                      value, 
                      0,                        // index
                      0,                        // data buffer
                      0,                        // size
                      CONTROL_TIMEOUT_JIFFIES);
        return retval;
}

static void gl_interrupt_complete (struct urb *urb, struct pt_regs *regs)
{
        int status = urb->status;
        
        switch (status) {
        case 0:
                /* success */
                break;
        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
                /* this urb is terminated, clean up */
                dbg("%s - urb shutting down with status: %d",
                                __FUNCTION__, status);
                return;
        default:
                dbg("%s - nonzero urb status received: %d",
                                __FUNCTION__, urb->status);
        }

        status = usb_submit_urb (urb, GFP_ATOMIC);
        if (status)
                err ("%s - usb_submit_urb failed with result %d",
                     __FUNCTION__, status);
}

static int gl_interrupt_read (struct usbnet *dev)
{
        struct gl_priv  *priv = dev->priv_data;
        int             retval;

        // issue usb interrupt read
        if (priv && priv->irq_urb) {
                // submit urb
                if ((retval = usb_submit_urb (priv->irq_urb, GFP_KERNEL)) != 0)
                        dbg ("gl_interrupt_read: submit fail - %X...", retval);
                else
                        dbg ("gl_interrupt_read: submit success...");
        }

        return 0;
}

// check whether another side is connected
static int genelink_check_connect (struct usbnet *dev)
{
        int                     retval;

        dbg ("genelink_check_connect...");

        // detect whether another side is connected
        if ((retval = gl_control_write (dev, GENELINK_CONNECT_WRITE, 0)) != 0) {
                dbg ("%s: genelink_check_connect write fail - %X",
                        dev->net->name, retval);
                return retval;
        }

        // usb interrupt read to ack another side 
        if ((retval = gl_interrupt_read (dev)) != 0) {
                dbg ("%s: genelink_check_connect read fail - %X",
                        dev->net->name, retval);
                return retval;
        }

        dbg ("%s: genelink_check_connect read success", dev->net->name);
        return 0;
}

// allocate and initialize the private data for genelink
static int genelink_init (struct usbnet *dev)
{
        struct gl_priv *priv;

        // allocate the private data structure
        if ((priv = kmalloc (sizeof *priv, GFP_KERNEL)) == 0) {
                dbg ("%s: cannot allocate private data per device",
                        dev->net->name);
                return -ENOMEM;
        }

        // allocate irq urb
        if ((priv->irq_urb = usb_alloc_urb (0, GFP_KERNEL)) == 0) {
                dbg ("%s: cannot allocate private irq urb per device",
                        dev->net->name);
                kfree (priv);
                return -ENOMEM;
        }

        // fill irq urb
        usb_fill_int_urb (priv->irq_urb, dev->udev,
                usb_rcvintpipe (dev->udev, GENELINK_INTERRUPT_PIPE),
                priv->irq_buf, INTERRUPT_BUFSIZE,
                gl_interrupt_complete, 0,
                GENELINK_INTERRUPT_INTERVAL);

        // set private data pointer
        dev->priv_data = priv;

        return 0;
}

// release the private data
static int genelink_free (struct usbnet *dev)
{
        struct gl_priv  *priv = dev->priv_data;

        if (!priv) 
                return 0;

// FIXME:  can't cancel here; it's synchronous, and
// should have happened earlier in any case (interrupt
// handling needs to be generic)

        // cancel irq urb first
        usb_kill_urb (priv->irq_urb);

        // free irq urb
        usb_free_urb (priv->irq_urb);

        // free the private data structure
        kfree (priv);

        return 0;
}

#endif

static int genelink_rx_fixup (struct usbnet *dev, struct sk_buff *skb)
{
        struct gl_header        *header;
        struct gl_packet        *packet;
        struct sk_buff          *gl_skb;
        u32                     size;

        header = (struct gl_header *) skb->data;

        // get the packet count of the received skb
        le32_to_cpus (&header->packet_count);
        if ((header->packet_count > GL_MAX_TRANSMIT_PACKETS)
                        || (header->packet_count < 0)) {
                dbg ("genelink: invalid received packet count %d",
                        header->packet_count);
                return 0;
        }

        // set the current packet pointer to the first packet
        packet = &header->packets;

        // decrement the length for the packet count size 4 bytes
        skb_pull (skb, 4);

        while (header->packet_count > 1) {
                // get the packet length
                size = packet->packet_length;

                // this may be a broken packet
                if (size > GL_MAX_PACKET_LEN) {
                        dbg ("genelink: invalid rx length %d", size);
                        return 0;
                }

                // allocate the skb for the individual packet
                gl_skb = alloc_skb (size, GFP_ATOMIC);
                if (gl_skb) {

                        // copy the packet data to the new skb
                        memcpy(skb_put(gl_skb, size), packet->packet_data, size);
                        skb_return (dev, skb);
                }

                // advance to the next packet
                packet = (struct gl_packet *)
                        &packet->packet_data [size];
                header->packet_count--;

                // shift the data pointer to the next gl_packet
                skb_pull (skb, size + 4);
        }

        // skip the packet length field 4 bytes
        skb_pull (skb, 4);

        if (skb->len > GL_MAX_PACKET_LEN) {
                dbg ("genelink: invalid rx length %d", skb->len);
                return 0;
        }
        return 1;
}

static struct sk_buff *
genelink_tx_fixup (struct usbnet *dev, struct sk_buff *skb, int flags)
{
        int     padlen;
        int     length = skb->len;
        int     headroom = skb_headroom (skb);
        int     tailroom = skb_tailroom (skb);
        u32     *packet_count;
        u32     *packet_len;

        // FIXME:  magic numbers, bleech
        padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1;

        if ((!skb_cloned (skb))
                        && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) {
                if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
                        skb->data = memmove (skb->head + (4 + 4*1),
                                             skb->data, skb->len);
                        skb->tail = skb->data + skb->len;
                }
        } else {
                struct sk_buff  *skb2;
                skb2 = skb_copy_expand (skb, (4 + 4*1) , padlen, flags);
                dev_kfree_skb_any (skb);
                skb = skb2;
                if (!skb)
                        return NULL;
        }

        // attach the packet count to the header
        packet_count = (u32 *) skb_push (skb, (4 + 4*1));
        packet_len = packet_count + 1;

        // FIXME little endian?
        *packet_count = 1;
        *packet_len = length;

        // add padding byte
        if ((skb->len % dev->maxpacket) == 0)
                skb_put (skb, 1);

        return skb;
}

static const struct driver_info genelink_info = {
        .description =  "Genesys GeneLink",
        .flags =        FLAG_FRAMING_GL | FLAG_NO_SETINT,
        .rx_fixup =     genelink_rx_fixup,
        .tx_fixup =     genelink_tx_fixup,

        .in = 1, .out = 2,

#ifdef  GENELINK_ACK
        .check_connect =genelink_check_connect,
#endif
};

#endif /* CONFIG_USB_GENESYS */



#ifdef  CONFIG_USB_NET1080
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * Netchip 1080 driver ... http://www.netchip.com
 * Used in LapLink cables
 *
 *-------------------------------------------------------------------------*/

#define dev_packet_id   data[0]
#define frame_errors    data[1]

/*
 * NetChip framing of ethernet packets, supporting additional error
 * checks for links that may drop bulk packets from inside messages.
 * Odd USB length == always short read for last usb packet.
 *      - nc_header
 *      - Ethernet header (14 bytes)
 *      - payload
 *      - (optional padding byte, if needed so length becomes odd)
 *      - nc_trailer
 *
 * This framing is to be avoided for non-NetChip devices.
 */

struct nc_header {              // packed:
        u16     hdr_len;                // sizeof nc_header (LE, all)
        u16     packet_len;             // payload size (including ethhdr)
        u16     packet_id;              // detects dropped packets
#define MIN_HEADER      6

        // all else is optional, and must start with:
        // u16  vendorId;               // from usb-if
        // u16  productId;
} __attribute__((__packed__));

#define PAD_BYTE        ((unsigned char)0xAC)

struct nc_trailer {
        u16     packet_id;
} __attribute__((__packed__));

// packets may use FLAG_FRAMING_NC and optional pad
#define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
                                + sizeof (struct ethhdr) \
                                + (mtu) \
                                + 1 \
                                + sizeof (struct nc_trailer))

#define MIN_FRAMED      FRAMED_SIZE(0)


/*
 * Zero means no timeout; else, how long a 64 byte bulk packet may be queued
 * before the hardware drops it.  If that's done, the driver will need to
 * frame network packets to guard against the dropped USB packets.  The win32
 * driver sets this for both sides of the link.
 */
#define NC_READ_TTL_MS  ((u8)255)       // ms

/*
 * We ignore most registers and EEPROM contents.
 */
#define REG_USBCTL      ((u8)0x04)
#define REG_TTL         ((u8)0x10)
#define REG_STATUS      ((u8)0x11)

/*
 * Vendor specific requests to read/write data
 */
#define REQUEST_REGISTER        ((u8)0x10)
#define REQUEST_EEPROM          ((u8)0x11)

static int
nc_vendor_read (struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
{
        int status = usb_control_msg (dev->udev,
                usb_rcvctrlpipe (dev->udev, 0),
                req,
                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                0, regnum,
                retval_ptr, sizeof *retval_ptr,
                CONTROL_TIMEOUT_JIFFIES);
        if (status > 0)
                status = 0;
        if (!status)
                le16_to_cpus (retval_ptr);
        return status;
}

static inline int
nc_register_read (struct usbnet *dev, u8 regnum, u16 *retval_ptr)
{
        return nc_vendor_read (dev, REQUEST_REGISTER, regnum, retval_ptr);
}

// no retval ... can become async, usable in_interrupt()
static void
nc_vendor_write (struct usbnet *dev, u8 req, u8 regnum, u16 value)
{
        usb_control_msg (dev->udev,
                usb_sndctrlpipe (dev->udev, 0),
                req,
                USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                value, regnum,
                NULL, 0,                        // data is in setup packet
                CONTROL_TIMEOUT_JIFFIES);
}

static inline void
nc_register_write (struct usbnet *dev, u8 regnum, u16 value)
{
        nc_vendor_write (dev, REQUEST_REGISTER, regnum, value);
}


#if 0
static void nc_dump_registers (struct usbnet *dev)
{
        u8      reg;
        u16     *vp = kmalloc (sizeof (u16));

        if (!vp) {
                dbg ("no memory?");
                return;
        }

        dbg ("%s registers:", dev->net->name);
        for (reg = 0; reg < 0x20; reg++) {
                int retval;

                // reading some registers is trouble
                if (reg >= 0x08 && reg <= 0xf)
                        continue;
                if (reg >= 0x12 && reg <= 0x1e)
                        continue;

                retval = nc_register_read (dev, reg, vp);
                if (retval < 0)
                        dbg ("%s reg [0x%x] ==> error %d",
                                dev->net->name, reg, retval);
                else
                        dbg ("%s reg [0x%x] = 0x%x",
                                dev->net->name, reg, *vp);
        }
        kfree (vp);
}
#endif


/*-------------------------------------------------------------------------*/

/*
 * Control register
 */

#define USBCTL_WRITABLE_MASK    0x1f0f
// bits 15-13 reserved, r/o
#define USBCTL_ENABLE_LANG      (1 << 12)
#define USBCTL_ENABLE_MFGR      (1 << 11)
#define USBCTL_ENABLE_PROD      (1 << 10)
#define USBCTL_ENABLE_SERIAL    (1 << 9)
#define USBCTL_ENABLE_DEFAULTS  (1 << 8)
// bits 7-4 reserved, r/o
#define USBCTL_FLUSH_OTHER      (1 << 3)
#define USBCTL_FLUSH_THIS       (1 << 2)
#define USBCTL_DISCONN_OTHER    (1 << 1)
#define USBCTL_DISCONN_THIS     (1 << 0)

static inline void nc_dump_usbctl (struct usbnet *dev, u16 usbctl)
{
#ifdef DEBUG
        devdbg (dev, "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s;"
                        " this%s%s;"
                        " other%s%s; r/o 0x%x",
                dev->udev->bus->bus_name, dev->udev->devpath,
                usbctl,
                (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
                (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
                (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
                (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
                (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",

                (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
                (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
                (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
                (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
                usbctl & ~USBCTL_WRITABLE_MASK
                );
#endif
}

/*-------------------------------------------------------------------------*/

/*
 * Status register
 */

#define STATUS_PORT_A           (1 << 15)

#define STATUS_CONN_OTHER       (1 << 14)
#define STATUS_SUSPEND_OTHER    (1 << 13)
#define STATUS_MAILBOX_OTHER    (1 << 12)
#define STATUS_PACKETS_OTHER(n) (((n) >> 8) && 0x03)

#define STATUS_CONN_THIS        (1 << 6)
#define STATUS_SUSPEND_THIS     (1 << 5)
#define STATUS_MAILBOX_THIS     (1 << 4)
#define STATUS_PACKETS_THIS(n)  (((n) >> 0) && 0x03)

#define STATUS_UNSPEC_MASK      0x0c8c
#define STATUS_NOISE_MASK       ((u16)~(0x0303|STATUS_UNSPEC_MASK))


static inline void nc_dump_status (struct usbnet *dev, u16 status)
{
#ifdef DEBUG
        devdbg (dev, "net1080 %s-%s status 0x%x:"
                        " this (%c) PKT=%d%s%s%s;"
                        " other PKT=%d%s%s%s; unspec 0x%x",
                dev->udev->bus->bus_name, dev->udev->devpath,
                status,

                // XXX the packet counts don't seem right
                // (1 at reset, not 0); maybe UNSPEC too

                (status & STATUS_PORT_A) ? 'A' : 'B',
                STATUS_PACKETS_THIS (status),
                (status & STATUS_CONN_THIS) ? " CON" : "",
                (status & STATUS_SUSPEND_THIS) ? " SUS" : "",
                (status & STATUS_MAILBOX_THIS) ? " MBOX" : "",

                STATUS_PACKETS_OTHER (status),
                (status & STATUS_CONN_OTHER) ? " CON" : "",
                (status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
                (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",

                status & STATUS_UNSPEC_MASK
                );
#endif
}

/*-------------------------------------------------------------------------*/

/*
 * TTL register
 */

#define TTL_THIS(ttl)   (0x00ff & ttl)
#define TTL_OTHER(ttl)  (0x00ff & (ttl >> 8))
#define MK_TTL(this,other)      ((u16)(((other)<<8)|(0x00ff&(this))))

static inline void nc_dump_ttl (struct usbnet *dev, u16 ttl)
{
#ifdef DEBUG
        devdbg (dev, "net1080 %s-%s ttl 0x%x this = %d, other = %d",
                dev->udev->bus->bus_name, dev->udev->devpath,
                ttl,

                TTL_THIS (ttl),
                TTL_OTHER (ttl)
                );
#endif
}

/*-------------------------------------------------------------------------*/

static int net1080_reset (struct usbnet *dev)
{
        u16             usbctl, status, ttl;
        u16             *vp = kmalloc (sizeof (u16), GFP_KERNEL);
        int             retval;

        if (!vp)
                return -ENOMEM;

        // nc_dump_registers (dev);

        if ((retval = nc_register_read (dev, REG_STATUS, vp)) < 0) {
                dbg ("can't read %s-%s status: %d",
                        dev->udev->bus->bus_name, dev->udev->devpath, retval);
                goto done;
        }
        status = *vp;
        // nc_dump_status (dev, status);

        if ((retval = nc_register_read (dev, REG_USBCTL, vp)) < 0) {
                dbg ("can't read USBCTL, %d", retval);
                goto done;
        }
        usbctl = *vp;
        // nc_dump_usbctl (dev, usbctl);

        nc_register_write (dev, REG_USBCTL,
                        USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);

        if ((retval = nc_register_read (dev, REG_TTL, vp)) < 0) {
                dbg ("can't read TTL, %d", retval);
                goto done;
        }
        ttl = *vp;
        // nc_dump_ttl (dev, ttl);

        nc_register_write (dev, REG_TTL,
                        MK_TTL (NC_READ_TTL_MS, TTL_OTHER (ttl)) );
        dbg ("%s: assigned TTL, %d ms", dev->net->name, NC_READ_TTL_MS);

        if (dev->msg_level >= 2)
                devinfo (dev, "port %c, peer %sconnected",
                        (status & STATUS_PORT_A) ? 'A' : 'B',
                        (status & STATUS_CONN_OTHER) ? "" : "dis"
                        );
        retval = 0;

done:
        kfree (vp);
        return retval;
}

static int net1080_check_connect (struct usbnet *dev)
{
        int                     retval;
        u16                     status;
        u16                     *vp = kmalloc (sizeof (u16), GFP_KERNEL);

        if (!vp)
                return -ENOMEM;
        retval = nc_register_read (dev, REG_STATUS, vp);
        status = *vp;
        kfree (vp);
        if (retval != 0) {
                dbg ("%s net1080_check_conn read - %d", dev->net->name, retval);
                return retval;
        }
        if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
                return -ENOLINK;
        return 0;
}

static void nc_flush_complete (struct urb *urb, struct pt_regs *regs)
{
        kfree (urb->context);
        usb_free_urb(urb);
}

static void nc_ensure_sync (struct usbnet *dev)
{
        dev->frame_errors++;
        if (dev->frame_errors > 5) {
                struct urb              *urb;
                struct usb_ctrlrequest  *req;
                int                     status;

                /* Send a flush */
                urb = usb_alloc_urb (0, SLAB_ATOMIC);
                if (!urb)
                        return;

                req = kmalloc (sizeof *req, GFP_ATOMIC);
                if (!req) {
                        usb_free_urb (urb);
                        return;
                }

                req->bRequestType = USB_DIR_OUT
                        | USB_TYPE_VENDOR
                        | USB_RECIP_DEVICE;
                req->bRequest = REQUEST_REGISTER;
                req->wValue = cpu_to_le16 (USBCTL_FLUSH_THIS
                                | USBCTL_FLUSH_OTHER);
                req->wIndex = cpu_to_le16 (REG_USBCTL);
                req->wLength = cpu_to_le16 (0);

                /* queue an async control request, we don't need
                 * to do anything when it finishes except clean up.
                 */
                usb_fill_control_urb (urb, dev->udev,
                        usb_sndctrlpipe (dev->udev, 0),
                        (unsigned char *) req,
                        NULL, 0,
                        nc_flush_complete, req);
                status = usb_submit_urb (urb, GFP_ATOMIC);
                if (status) {
                        kfree (req);
                        usb_free_urb (urb);
                        return;
                }

                devdbg (dev, "flush net1080; too many framing errors");
                dev->frame_errors = 0;
        }
}

static int net1080_rx_fixup (struct usbnet *dev, struct sk_buff *skb)
{
        struct nc_header        *header;
        struct nc_trailer       *trailer;

        if (!(skb->len & 0x01)
                        || MIN_FRAMED > skb->len
                        || skb->len > FRAMED_SIZE (dev->net->mtu)) {
                dev->stats.rx_frame_errors++;
                dbg ("rx framesize %d range %d..%d mtu %d", skb->len,
                        (int)MIN_FRAMED, (int)FRAMED_SIZE (dev->net->mtu),
                        dev->net->mtu);
                nc_ensure_sync (dev);
                return 0;
        }

        header = (struct nc_header *) skb->data;
        le16_to_cpus (&header->hdr_len);
        le16_to_cpus (&header->packet_len);
        if (FRAMED_SIZE (header->packet_len) > MAX_PACKET) {
                dev->stats.rx_frame_errors++;
                dbg ("packet too big, %d", header->packet_len);
                nc_ensure_sync (dev);
                return 0;
        } else if (header->hdr_len < MIN_HEADER) {
                dev->stats.rx_frame_errors++;
                dbg ("header too short, %d", header->hdr_len);
                nc_ensure_sync (dev);
                return 0;

        } else if (header->hdr_len > MIN_HEADER) {
                // out of band data for us?
                dbg ("header OOB, %d bytes",
                        header->hdr_len - MIN_HEADER);
                nc_ensure_sync (dev);
                // switch (vendor/product ids) { ... }
        }
        skb_pull (skb, header->hdr_len);

        trailer = (struct nc_trailer *)
                (skb->data + skb->len - sizeof *trailer);
        skb_trim (skb, skb->len - sizeof *trailer);

        if ((header->packet_len & 0x01) == 0) {
                if (skb->data [header->packet_len] != PAD_BYTE) {
                        dev->stats.rx_frame_errors++;
                        dbg ("bad pad");
                        return 0;
                }
                skb_trim (skb, skb->len - 1);
        }
        if (skb->len != header->packet_len) {
                dev->stats.rx_frame_errors++;
                dbg ("bad packet len %d (expected %d)",
                        skb->len, header->packet_len);
                nc_ensure_sync (dev);
                return 0;
        }
        if (header->packet_id != get_unaligned (&trailer->packet_id)) {
                dev->stats.rx_fifo_errors++;
                dbg ("(2+ dropped) rx packet_id mismatch 0x%x 0x%x",
                        header->packet_id, trailer->packet_id);
                return 0;
        }
#if 0
        devdbg (dev, "frame <rx h %d p %d id %d", header->hdr_len,
                header->packet_len, header->packet_id);
#endif
        dev->frame_errors = 0;
        return 1;
}

static struct sk_buff *
net1080_tx_fixup (struct usbnet *dev, struct sk_buff *skb, int flags)
{
        int                     padlen;
        struct sk_buff          *skb2;

        padlen = ((skb->len + sizeof (struct nc_header)
                        + sizeof (struct nc_trailer)) & 0x01) ? 0 : 1;
        if (!skb_cloned (skb)) {
                int     headroom = skb_headroom (skb);
                int     tailroom = skb_tailroom (skb);

                if ((padlen + sizeof (struct nc_trailer)) <= tailroom
                            && sizeof (struct nc_header) <= headroom)
                        /* There's enough head and tail room */
                        return skb;

                if ((sizeof (struct nc_header) + padlen
                                        + sizeof (struct nc_trailer)) <
                                (headroom + tailroom)) {
                        /* There's enough total room, so just readjust */
                        skb->data = memmove (skb->head
                                                + sizeof (struct nc_header),
                                            skb->data, skb->len);
                        skb->tail = skb->data + skb->len;
                        return skb;
                }
        }

        /* Create a new skb to use with the correct size */
        skb2 = skb_copy_expand (skb,
                                sizeof (struct nc_header),
                                sizeof (struct nc_trailer) + padlen,
                                flags);
        dev_kfree_skb_any (skb);
        return skb2;
}

static const struct driver_info net1080_info = {
        .description =  "NetChip TurboCONNECT",
        .flags =        FLAG_FRAMING_NC,
        .reset =        net1080_reset,
        .check_connect =net1080_check_connect,
        .rx_fixup =     net1080_rx_fixup,
        .tx_fixup =     net1080_tx_fixup,
};

#endif /* CONFIG_USB_NET1080 */



#ifdef CONFIG_USB_PL2301
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * Prolific PL-2301/PL-2302 driver ... http://www.prolifictech.com
 *
 * The protocol and handshaking used here should be bug-compatible
 * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
 *
 *-------------------------------------------------------------------------*/

/*
 * Bits 0-4 can be used for software handshaking; they're set from
 * one end, cleared from the other, "read" with the interrupt byte.
 */
#define PL_S_EN         (1<<7)          /* (feature only) suspend enable */
/* reserved bit -- rx ready (6) ? */
#define PL_TX_READY     (1<<5)          /* (interrupt only) transmit ready */
#define PL_RESET_OUT    (1<<4)          /* reset output pipe */
#define PL_RESET_IN     (1<<3)          /* reset input pipe */
#define PL_TX_C         (1<<2)          /* transmission complete */
#define PL_TX_REQ       (1<<1)          /* transmission received */
#define PL_PEER_E       (1<<0)          /* peer exists */

static inline int
pl_vendor_req (struct usbnet *dev, u8 req, u8 val, u8 index)
{
        return usb_control_msg (dev->udev,
                usb_rcvctrlpipe (dev->udev, 0),
                req,
                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                val, index,
                NULL, 0,
                CONTROL_TIMEOUT_JIFFIES);
}

static inline int
pl_clear_QuickLink_features (struct usbnet *dev, int val)
{
        return pl_vendor_req (dev, 1, (u8) val, 0);
}

static inline int
pl_set_QuickLink_features (struct usbnet *dev, int val)
{
        return pl_vendor_req (dev, 3, (u8) val, 0);
}

/*-------------------------------------------------------------------------*/

static int pl_reset (struct usbnet *dev)
{
        /* some units seem to need this reset, others reject it utterly.
         * FIXME be more like "naplink" or windows drivers.
         */
        (void) pl_set_QuickLink_features (dev,
                PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
        return 0;
}

static const struct driver_info prolific_info = {
        .description =  "Prolific PL-2301/PL-2302",
        .flags =        FLAG_NO_SETINT,
                /* some PL-2302 versions seem to fail usb_set_interface() */
        .reset =        pl_reset,
};

#endif /* CONFIG_USB_PL2301 */


#ifdef CONFIG_USB_KC2190
#define HAVE_HARDWARE
static const struct driver_info kc2190_info = {
        .description =  "KC Technology KC-190",
};
#endif /* CONFIG_USB_KC2190 */


#ifdef  CONFIG_USB_ARMLINUX
#define HAVE_HARDWARE

/*-------------------------------------------------------------------------
 *
 * Intel's SA-1100 chip integrates basic USB support, and is used
 * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
 * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
 * network using minimal USB framing data.
 *
 * This describes the driver currently in standard ARM Linux kernels.
 * The Zaurus uses a different driver (see later).
 *
 * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
 * and different USB endpoint numbering than the SA1100 devices.  The
 * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
 * so we rely on the endpoint descriptors.
 *
 *-------------------------------------------------------------------------*/

static const struct driver_info linuxdev_info = {
        .description =  "Linux Device",
        .check_connect = always_connected,
};

static const struct driver_info yopy_info = {
        .description =  "Yopy",
        .check_connect = always_connected,
};

static const struct driver_info blob_info = {
        .description =  "Boot Loader OBject",
        .check_connect = always_connected,
};

#endif  /* CONFIG_USB_ARMLINUX */


#ifdef CONFIG_USB_ZAURUS
#define HAVE_HARDWARE

#include <linux/crc32.h>

/*-------------------------------------------------------------------------
 *
 * Zaurus is also a SA-1110 based PDA, but one using a different driver
 * (and framing) for its USB slave/gadget controller than the case above.
 *
 * For the current version of that driver, the main way that framing is
 * nonstandard (also from perspective of the CDC ethernet model!) is a
 * crc32, added to help detect when some sa1100 usb-to-memory DMA errata
 * haven't been fully worked around.
 *
 * PXA based models use the same framing, and also can't implement
 * set_interface properly.
 *
 *-------------------------------------------------------------------------*/

static struct sk_buff *
zaurus_tx_fixup (struct usbnet *dev, struct sk_buff *skb, int flags)
{
        int                     padlen;
        struct sk_buff          *skb2;

        padlen = 2;
        if (!skb_cloned (skb)) {
                int     tailroom = skb_tailroom (skb);
                if ((padlen + 4) <= tailroom)
                        goto done;
        }
        skb2 = skb_copy_expand (skb, 0, 4 + padlen, flags);
        dev_kfree_skb_any (skb);
        skb = skb2;
        if (skb) {
                u32             fcs;
done:
                fcs = crc32_le (~0, skb->data, skb->len);
                fcs = ~fcs;

                *skb_put (skb, 1) = fcs       & 0xff;
                *skb_put (skb, 1) = (fcs>> 8) & 0xff;
                *skb_put (skb, 1) = (fcs>>16) & 0xff;
                *skb_put (skb, 1) = (fcs>>24) & 0xff;
        }
        return skb;
}

static const struct driver_info zaurus_sl5x00_info = {
        .description =  "Sharp Zaurus SL-5x00",
        .flags =        FLAG_FRAMING_Z,
        .check_connect = always_connected,
        .bind =         generic_cdc_bind,
        .unbind =       cdc_unbind,
        .tx_fixup =     zaurus_tx_fixup,
};
#define ZAURUS_STRONGARM_INFO   ((unsigned long)&zaurus_sl5x00_info)

static const struct driver_info zaurus_pxa_info = {
        .description =  "Sharp Zaurus, PXA-2xx based",
        .flags =        FLAG_FRAMING_Z,
        .check_connect = always_connected,
        .bind =         generic_cdc_bind,
        .unbind =       cdc_unbind,
        .tx_fixup =     zaurus_tx_fixup,
};
#define ZAURUS_PXA_INFO         ((unsigned long)&zaurus_pxa_info)

static const struct driver_info olympus_mxl_info = {
        .description =  "Olympus R1000",
        .flags =        FLAG_FRAMING_Z,
        .check_connect = always_connected,
        .bind =         generic_cdc_bind,
        .unbind =       cdc_unbind,
        .tx_fixup =     zaurus_tx_fixup,
};
#define OLYMPUS_MXL_INFO        ((unsigned long)&olympus_mxl_info)

#else

/* blacklist all those devices */
#define ZAURUS_STRONGARM_INFO   0
#define ZAURUS_PXA_INFO         0
#define OLYMPUS_MXL_INFO        0

#endif


/*-------------------------------------------------------------------------
 *
 * Network Device Driver (peer link to "Host Device", from USB host)
 *
 *-------------------------------------------------------------------------*/

static int usbnet_change_mtu (struct net_device *net, int new_mtu)
{
        struct usbnet   *dev = netdev_priv(net);

        if (new_mtu <= MIN_PACKET || new_mtu > MAX_PACKET)
                return -EINVAL;
#ifdef  CONFIG_USB_NET1080
        if (((dev->driver_info->flags) & FLAG_FRAMING_NC)) {
                if (FRAMED_SIZE (new_mtu) > MAX_PACKET)
                        return -EINVAL;
        }
#endif
#ifdef  CONFIG_USB_GENESYS
        if (((dev->driver_info->flags) & FLAG_FRAMING_GL)
                        && new_mtu > GL_MAX_PACKET_LEN)
                return -EINVAL;
#endif
        // no second zero-length packet read wanted after mtu-sized packets
        if (((new_mtu + sizeof (struct ethhdr)) % dev->maxpacket) == 0)
                return -EDOM;
        net->mtu = new_mtu;
        return 0;
}

/*-------------------------------------------------------------------------*/

static struct net_device_stats *usbnet_get_stats (struct net_device *net)
{
        struct usbnet   *dev = netdev_priv(net);
        return &dev->stats;
}

/*-------------------------------------------------------------------------*/

/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 * completion callbacks.  2.5 should have fixed those bugs...
 */

static void defer_bh (struct usbnet *dev, struct sk_buff *skb)
{
        struct sk_buff_head     *list = skb->list;
        unsigned long           flags;

        spin_lock_irqsave (&list->lock, flags);
        __skb_unlink (skb, list);
        spin_unlock (&list->lock);
        spin_lock (&dev->done.lock);
        __skb_queue_tail (&dev->done, skb);
        if (dev->done.qlen == 1)
                tasklet_schedule (&dev->bh);
        spin_unlock_irqrestore (&dev->done.lock, flags);
}

/* some work can't be done in tasklets, so we use keventd
 *
 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 * but tasklet_schedule() doesn't.  hope the failure is rare.
 */
static void defer_kevent (struct usbnet *dev, int work)
{
        set_bit (work, &dev->flags);
        if (!schedule_work (&dev->kevent))
                deverr (dev, "kevent %d may have been dropped", work);
        else
                devdbg (dev, "kevent %d scheduled", work);
}

/*-------------------------------------------------------------------------*/

static void rx_complete (struct urb *urb, struct pt_regs *regs);

static void rx_submit (struct usbnet *dev, struct urb *urb, int flags)
{
        struct sk_buff          *skb;
        struct skb_data         *entry;
        int                     retval = 0;
        unsigned long           lockflags;
        size_t                  size;

#ifdef CONFIG_USB_NET1080
        if (dev->driver_info->flags & FLAG_FRAMING_NC)
                size = FRAMED_SIZE (dev->net->mtu);
        else
#endif
#ifdef CONFIG_USB_GENESYS
        if (dev->driver_info->flags & FLAG_FRAMING_GL)
                size = GL_RCV_BUF_SIZE;
        else
#endif
#ifdef CONFIG_USB_ZAURUS
        if (dev->driver_info->flags & FLAG_FRAMING_Z)
                size = 6 + (sizeof (struct ethhdr) + dev->net->mtu);
        else
#endif
#ifdef CONFIG_USB_RNDIS
        if (dev->driver_info->flags & FLAG_FRAMING_RN)
                size = RNDIS_MAX_TRANSFER;
        else
#endif
                size = (sizeof (struct ethhdr) + dev->net->mtu);

        if ((skb = alloc_skb (size, flags)) == NULL) {
                devdbg (dev, "no rx skb");
                defer_kevent (dev, EVENT_RX_MEMORY);
                usb_free_urb (urb);
                return;
        }

        entry = (struct skb_data *) skb->cb;
        entry->urb = urb;
        entry->dev = dev;
        entry->state = rx_start;
        entry->length = 0;

        usb_fill_bulk_urb (urb, dev->udev, dev->in,
                skb->data, size, rx_complete, skb);
        urb->transfer_flags |= URB_ASYNC_UNLINK;

        spin_lock_irqsave (&dev->rxq.lock, lockflags);

        if (netif_running (dev->net)
                        && netif_device_present (dev->net)
                        && !test_bit (EVENT_RX_HALT, &dev->flags)) {
                switch (retval = usb_submit_urb (urb, GFP_ATOMIC)){ 
                case -EPIPE:
                        defer_kevent (dev, EVENT_RX_HALT);
                        break;
                case -ENOMEM:
                        defer_kevent (dev, EVENT_RX_MEMORY);
                        break;
                case -ENODEV:
                        devdbg (dev, "device gone");
                        netif_device_detach (dev->net);
                        break;
                default:
                        devdbg (dev, "rx submit, %d", retval);
                        tasklet_schedule (&dev->bh);
                        break;
                case 0:
                        __skb_queue_tail (&dev->rxq, skb);
                }
        } else {
                devdbg (dev, "rx: stopped");
                retval = -ENOLINK;
        }
        spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
        if (retval) {
                dev_kfree_skb_any (skb);
                usb_free_urb (urb);
        }
}


/*-------------------------------------------------------------------------*/

static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
{
        if (dev->driver_info->rx_fixup
                        && !dev->driver_info->rx_fixup (dev, skb))
                goto error;
        // else network stack removes extra byte if we forced a short packet

        if (skb->len)
                skb_return (dev, skb);
        else {
                devdbg (dev, "drop");
error:
                dev->stats.rx_errors++;
                skb_queue_tail (&dev->done, skb);
        }
}

/*-------------------------------------------------------------------------*/

static void rx_complete (struct urb *urb, struct pt_regs *regs)
{
        struct sk_buff          *skb = (struct sk_buff *) urb->context;
        struct skb_data         *entry = (struct skb_data *) skb->cb;
        struct usbnet           *dev = entry->dev;
        int                     urb_status = urb->status;

        skb_put (skb, urb->actual_length);
        entry->state = rx_done;
        entry->urb = NULL;

        switch (urb_status) {
            // success
            case 0:
                if (MIN_PACKET > skb->len || skb->len > MAX_PACKET) {
                        entry->state = rx_cleanup;
                        dev->stats.rx_errors++;
                        dev->stats.rx_length_errors++;
                        devdbg (dev, "rx length %d", skb->len);
                }
                break;

            // stalls need manual reset. this is rare ... except that
            // when going through USB 2.0 TTs, unplug appears this way.
            // we avoid the highspeed version of the ETIMEOUT/EILSEQ
            // storm, recovering as needed.
            case -EPIPE:
                dev->stats.rx_errors++;
                defer_kevent (dev, EVENT_RX_HALT);
                // FALLTHROUGH

            // software-driven interface shutdown
            case -ECONNRESET:           // async unlink
            case -ESHUTDOWN:            // hardware gone
#ifdef  VERBOSE
                devdbg (dev, "rx shutdown, code %d", urb_status);
#endif
                goto block;

            // we get controller i/o faults during khubd disconnect() delays.
            // throttle down resubmits, to avoid log floods; just temporarily,
            // so we still recover when the fault isn't a khubd delay.
            case -EPROTO:               // ehci
            case -ETIMEDOUT:            // ohci
            case -EILSEQ:               // uhci
                dev->stats.rx_errors++;
                if (!timer_pending (&dev->delay)) {
                        mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
                        devdbg (dev, "rx throttle %d", urb_status);
                }
block:
                entry->state = rx_cleanup;
                entry->urb = urb;
                urb = NULL;
                break;

            // data overrun ... flush fifo?
            case -EOVERFLOW:
                dev->stats.rx_over_errors++;
                // FALLTHROUGH
            
            default:
                entry->state = rx_cleanup;
                dev->stats.rx_errors++;
                devdbg (dev, "rx status %d", urb_status);
                break;
        }

        defer_bh (dev, skb);

        if (urb) {
                if (netif_running (dev->net)
                                && !test_bit (EVENT_RX_HALT, &dev->flags)) {
                        rx_submit (dev, urb, GFP_ATOMIC);
                        return;
                }
                usb_free_urb (urb);
        }
#ifdef  VERBOSE
        devdbg (dev, "no read resubmitted");
#endif /* VERBOSE */
}

/*-------------------------------------------------------------------------*/

// unlink pending rx/tx; completion handlers do all other cleanup

static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
{
        unsigned long           flags;
        struct sk_buff          *skb, *skbnext;
        int                     count = 0;

        spin_lock_irqsave (&q->lock, flags);
        for (skb = q->next; skb != (struct sk_buff *) q; skb = skbnext) {
                struct skb_data         *entry;
                struct urb              *urb;
                int                     retval;

                entry = (struct skb_data *) skb->cb;
                urb = entry->urb;
                skbnext = skb->next;

                // during some PM-driven resume scenarios,
                // these (async) unlinks complete immediately
                retval = usb_unlink_urb (urb);
                if (retval != -EINPROGRESS && retval != 0)
                        devdbg (dev, "unlink urb err, %d", retval);
                else
                        count++;
        }
        spin_unlock_irqrestore (&q->lock, flags);
        return count;
}


/*-------------------------------------------------------------------------*/

// precondition: never called in_interrupt

static int usbnet_stop (struct net_device *net)
{
        struct usbnet           *dev = netdev_priv(net);
        int                     temp;
        DECLARE_WAIT_QUEUE_HEAD (unlink_wakeup); 
        DECLARE_WAITQUEUE (wait, current);

        netif_stop_queue (net);

        if (dev->msg_level >= 2)
                devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
                        dev->stats.rx_packets, dev->stats.tx_packets, 
                        dev->stats.rx_errors, dev->stats.tx_errors
                        );

        // ensure there are no more active urbs
        add_wait_queue (&unlink_wakeup, &wait);
        dev->wait = &unlink_wakeup;
        temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);

        // maybe wait for deletions to finish.
        while (skb_queue_len (&dev->rxq)
                        && skb_queue_len (&dev->txq)
                        && skb_queue_len (&dev->done)) {
                msleep(UNLINK_TIMEOUT_MS);
                devdbg (dev, "waited for %d urb completions", temp);
        }
        dev->wait = NULL;
        remove_wait_queue (&unlink_wakeup, &wait); 

        /* deferred work (task, timer, softirq) must also stop.
         * can't flush_scheduled_work() until we drop rtnl (later),
         * else workers could deadlock; so make workers a NOP.
         */
        dev->flags = 0;
        del_timer_sync (&dev->delay);
        tasklet_kill (&dev->bh);

        return 0;
}

/*-------------------------------------------------------------------------*/

// posts reads, and enables write queuing

// precondition: never called in_interrupt

static int usbnet_open (struct net_device *net)
{
        struct usbnet           *dev = netdev_priv(net);
        int                     retval = 0;
        struct driver_info      *info = dev->driver_info;

        // put into "known safe" state
        if (info->reset && (retval = info->reset (dev)) < 0) {
                devinfo (dev, "open reset fail (%d) usbnet usb-%s-%s, %s",
                        retval,
                        dev->udev->bus->bus_name, dev->udev->devpath,
                        info->description);
                goto done;
        }

        // insist peer be connected
        if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
                devdbg (dev, "can't open; %d", retval);
                goto done;
        }

        netif_start_queue (net);
        if (dev->msg_level >= 2) {
                char    *framing;

                if (dev->driver_info->flags & FLAG_FRAMING_NC)
                        framing = "NetChip";
                else if (dev->driver_info->flags & FLAG_FRAMING_GL)
                        framing = "GeneSys";
                else if (dev->driver_info->flags & FLAG_FRAMING_Z)
                        framing = "Zaurus";
                else if (dev->driver_info->flags & FLAG_FRAMING_RN)
                        framing = "RNDIS";
                else
                        framing = "simple";

                devinfo (dev, "open: enable queueing "
                                "(rx %d, tx %d) mtu %d %s framing",
                        RX_QLEN (dev), TX_QLEN (dev), dev->net->mtu,
                        framing);
        }

        // delay posting reads until we're fully open
        tasklet_schedule (&dev->bh);
done:
        return retval;
}

/*-------------------------------------------------------------------------*/

static void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
{
        struct usbnet *dev = netdev_priv(net);

        strncpy (info->driver, driver_name, sizeof info->driver);
        strncpy (info->version, DRIVER_VERSION, sizeof info->version);
        strncpy (info->fw_version, dev->driver_info->description,
                sizeof info->fw_version);
        usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
}

static u32 usbnet_get_link (struct net_device *net)
{
        struct usbnet *dev = netdev_priv(net);

        /* If a check_connect is defined, return it's results */
        if (dev->driver_info->check_connect)
                return dev->driver_info->check_connect (dev) == 0;

        /* Otherwise, we're up to avoid breaking scripts */
        return 1;
}

static u32 usbnet_get_msglevel (struct net_device *net)
{
        struct usbnet *dev = netdev_priv(net);

        return dev->msg_level;
}

static void usbnet_set_msglevel (struct net_device *net, u32 level)
{
        struct usbnet *dev = netdev_priv(net);

        dev->msg_level = level;
}

static int usbnet_ioctl (struct net_device *net, struct ifreq *rq, int cmd)
{
#ifdef NEED_MII
        {
        struct usbnet *dev = netdev_priv(net);

        if (dev->mii.mdio_read != NULL && dev->mii.mdio_write != NULL)
                return generic_mii_ioctl(&dev->mii, if_mii(rq), cmd, NULL);
        }
#endif
        return -EOPNOTSUPP;
}

/*-------------------------------------------------------------------------*/

/* work that cannot be done in interrupt context uses keventd.
 *
 * NOTE:  with 2.5 we could do more of this using completion callbacks,
 * especially now that control transfers can be queued.
 */
static void
kevent (void *data)
{
        struct usbnet           *dev = data;
        int                     status;

        /* usb_clear_halt() needs a thread context */
        if (test_bit (EVENT_TX_HALT, &dev->flags)) {
                unlink_urbs (dev, &dev->txq);
                status = usb_clear_halt (dev->udev, dev->out);
                if (status < 0 && status != -EPIPE)
                        deverr (dev, "can't clear tx halt, status %d",
                                status);
                else {
                        clear_bit (EVENT_TX_HALT, &dev->flags);
                        netif_wake_queue (dev->net);
                }
        }
        if (test_bit (EVENT_RX_HALT, &dev->flags)) {
                unlink_urbs (dev, &dev->rxq);
                status = usb_clear_halt (dev->udev, dev->in);
                if (status < 0 && status != -EPIPE)
                        deverr (dev, "can't clear rx halt, status %d",
                                status);
                else {
                        clear_bit (EVENT_RX_HALT, &dev->flags);
                        tasklet_schedule (&dev->bh);
                }
        }

        /* tasklet could resubmit itself forever if memory is tight */
        if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
                struct urb      *urb = NULL;

                if (netif_running (dev->net))
                        urb = usb_alloc_urb (0, GFP_KERNEL);
                else
                        clear_bit (EVENT_RX_MEMORY, &dev->flags);
                if (urb != NULL) {
                        clear_bit (EVENT_RX_MEMORY, &dev->flags);
                        rx_submit (dev, urb, GFP_KERNEL);
                        tasklet_schedule (&dev->bh);
                }
        }

        if (dev->flags)
                devdbg (dev, "kevent done, flags = 0x%lx",
                        dev->flags);
}

/*-------------------------------------------------------------------------*/

static void tx_complete (struct urb *urb, struct pt_regs *regs)
{
        struct sk_buff          *skb = (struct sk_buff *) urb->context;
        struct skb_data         *entry = (struct skb_data *) skb->cb;
        struct usbnet           *dev = entry->dev;

        if (urb->status == 0) {
                dev->stats.tx_packets++;
                dev->stats.tx_bytes += entry->length;
        } else {
                dev->stats.tx_errors++;

                switch (urb->status) {
                case -EPIPE:
                        defer_kevent (dev, EVENT_TX_HALT);
                        break;

                // like rx, tx gets controller i/o faults during khubd delays
                // and so it uses the same throttling mechanism.
                case -EPROTO:           // ehci
                case -ETIMEDOUT:        // ohci
                case -EILSEQ:           // uhci
                        if (!timer_pending (&dev->delay)) {
                                mod_timer (&dev->delay,
                                        jiffies + THROTTLE_JIFFIES);
                                devdbg (dev, "tx throttle %d", urb->status);
                        }
                        netif_stop_queue (dev->net);
                        break;
                default:
                        devdbg (dev, "tx err %d", entry->urb->status);
                        break;
                }
        }

        urb->dev = NULL;
        entry->state = tx_done;
        defer_bh (dev, skb);
}

/*-------------------------------------------------------------------------*/

static void usbnet_tx_timeout (struct net_device *net)
{
        struct usbnet           *dev = netdev_priv(net);

        unlink_urbs (dev, &dev->txq);
        tasklet_schedule (&dev->bh);

        // FIXME: device recovery -- reset?
}

/*-------------------------------------------------------------------------*/

static int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
{
        struct usbnet           *dev = netdev_priv(net);
        int                     length;
        int                     retval = NET_XMIT_SUCCESS;
        struct urb              *urb = NULL;
        struct skb_data         *entry;
        struct driver_info      *info = dev->driver_info;
        unsigned long           flags;
#ifdef  CONFIG_USB_NET1080
        struct nc_header        *header = NULL;
        struct nc_trailer       *trailer = NULL;
#endif  /* CONFIG_USB_NET1080 */

        // some devices want funky USB-level framing, for
        // win32 driver (usually) and/or hardware quirks
        if (info->tx_fixup) {
                skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
                if (!skb) {
                        devdbg (dev, "can't tx_fixup skb");
                        goto drop;
                }
        }
        length = skb->len;

        if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
                devdbg (dev, "no urb");
                goto drop;
        }

        entry = (struct skb_data *) skb->cb;
        entry->urb = urb;
        entry->dev = dev;
        entry->state = tx_start;
        entry->length = length;

        // FIXME: reorganize a bit, so that fixup() fills out NetChip
        // framing too. (Packet ID update needs the spinlock...)
        // [ BETTER:  we already own net->xmit_lock, that's enough ]

#ifdef  CONFIG_USB_NET1080
        if (info->flags & FLAG_FRAMING_NC) {
                header = (struct nc_header *) skb_push (skb, sizeof *header);
                header->hdr_len = cpu_to_le16 (sizeof (*header));
                header->packet_len = cpu_to_le16 (length);
                if (!((skb->len + sizeof *trailer) & 0x01))
                        *skb_put (skb, 1) = PAD_BYTE;
                trailer = (struct nc_trailer *) skb_put (skb, sizeof *trailer);
        }
#endif  /* CONFIG_USB_NET1080 */

        usb_fill_bulk_urb (urb, dev->udev, dev->out,
                        skb->data, skb->len, tx_complete, skb);
        urb->transfer_flags |= URB_ASYNC_UNLINK;

        /* don't assume the hardware handles USB_ZERO_PACKET
         * NOTE:  strictly conforming cdc-ether devices should expect
         * the ZLP here, but ignore the one-byte packet.
         *
         * FIXME zero that byte, if it doesn't require a new skb.
         */
        if ((length % dev->maxpacket) == 0)
                urb->transfer_buffer_length++;

        spin_lock_irqsave (&dev->txq.lock, flags);

#ifdef  CONFIG_USB_NET1080
        if (info->flags & FLAG_FRAMING_NC) {
                header->packet_id = cpu_to_le16 ((u16)dev->dev_packet_id++);
                put_unaligned (header->packet_id, &trailer->packet_id);
#if 0
                devdbg (dev, "frame >tx h %d p %d id %d",
                        header->hdr_len, header->packet_len,
                        header->packet_id);
#endif
        }
#endif  /* CONFIG_USB_NET1080 */

        switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
        case -EPIPE:
                netif_stop_queue (net);
                defer_kevent (dev, EVENT_TX_HALT);
                break;
        default:
                devdbg (dev, "tx: submit urb err %d", retval);
                break;
        case 0:
                net->trans_start = jiffies;
                __skb_queue_tail (&dev->txq, skb);
                if (dev->txq.qlen >= TX_QLEN (dev))
                        netif_stop_queue (net);
        }
        spin_unlock_irqrestore (&dev->txq.lock, flags);

        if (retval) {
                devdbg (dev, "drop, code %d", retval);
drop:
                retval = NET_XMIT_SUCCESS;
                dev->stats.tx_dropped++;
                if (skb)
                        dev_kfree_skb_any (skb);
                usb_free_urb (urb);
#ifdef  VERBOSE
        } else {
                devdbg (dev, "> tx, len %d, type 0x%x",
                        length, skb->protocol);
#endif
        }
        return retval;
}


/*-------------------------------------------------------------------------*/

// tasklet (work deferred from completions, in_irq) or timer

static void usbnet_bh (unsigned long param)
{
        struct usbnet           *dev = (struct usbnet *) param;
        struct sk_buff          *skb;
        struct skb_data         *entry;

        while ((skb = skb_dequeue (&dev->done))) {
                entry = (struct skb_data *) skb->cb;
                switch (entry->state) {
                    case rx_done:
                        entry->state = rx_cleanup;
                        rx_process (dev, skb);
                        continue;
                    case tx_done:
                    case rx_cleanup:
                        usb_free_urb (entry->urb);
                        dev_kfree_skb (skb);
                        continue;
                    default:
                        devdbg (dev, "bogus skb state %d", entry->state);
                }
        }

        // waiting for all pending urbs to complete?
        if (dev->wait) {

                if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
                        wake_up (dev->wait);
                }

        // or are we maybe short a few urbs?
        } else if (netif_running (dev->net)
                        && netif_device_present (dev->net)
                        && !timer_pending (&dev->delay)
                        && !test_bit (EVENT_RX_HALT, &dev->flags)) {
                int     temp = dev->rxq.qlen;
                int     qlen = RX_QLEN (dev);

                if (temp < qlen) {
                        struct urb      *urb;
                        int             i;

                        // don't refill the queue all at once
                        for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
                                urb = usb_alloc_urb (0, GFP_ATOMIC);
                                if (urb != NULL)
                                        rx_submit (dev, urb, GFP_ATOMIC);
                        }
                        if (temp != dev->rxq.qlen)
                                devdbg (dev, "rxqlen %d --> %d",
                                                temp, dev->rxq.qlen);
                        if (dev->rxq.qlen < qlen)
                                tasklet_schedule (&dev->bh);
                }
                if (dev->txq.qlen < TX_QLEN (dev))
                        netif_wake_queue (dev->net);
        }
}



/*-------------------------------------------------------------------------
 *
 * USB Device Driver support
 *
 *-------------------------------------------------------------------------*/
 
// precondition: never called in_interrupt

static void usbnet_disconnect (struct usb_interface *intf)
{
        struct usbnet           *dev;
        struct usb_device       *xdev;
        struct net_device       *net;

        dev = usb_get_intfdata(intf);
        usb_set_intfdata(intf, NULL);
        if (!dev)
                return;

        xdev = interface_to_usbdev (intf);

        devinfo (dev, "unregister usbnet usb-%s-%s, %s",
                xdev->bus->bus_name, xdev->devpath,
                dev->driver_info->description);
        
        net = dev->net;
        unregister_netdev (net);

        /* we don't hold rtnl here ... */
        flush_scheduled_work ();

        if (dev->driver_info->unbind)
                dev->driver_info->unbind (dev, intf);

        free_netdev(net);
        usb_put_dev (xdev);
}


/*-------------------------------------------------------------------------*/

static struct ethtool_ops usbnet_ethtool_ops;

// precondition: never called in_interrupt

static int
usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
{
        struct usbnet                   *dev;
        struct net_device               *net;
        struct usb_host_interface       *interface;
        struct driver_info              *info;
        struct usb_device               *xdev;
        int                             status;

        info = (struct driver_info *) prod->driver_info;
        if (!info) {
                dev_dbg (&udev->dev, "blacklisted by %s\n", driver_name);
                return -ENODEV;
        }
        xdev = interface_to_usbdev (udev);
        interface = udev->cur_altsetting;

        usb_get_dev (xdev);

        status = -ENOMEM;

        // set up our own records
        net = alloc_etherdev(sizeof(*dev));
        if (!net) {
                dbg ("can't kmalloc dev");
                goto out;
        }

        dev = netdev_priv(net);
        dev->udev = xdev;
        dev->driver_info = info;
        dev->msg_level = msg_level;
        skb_queue_head_init (&dev->rxq);
        skb_queue_head_init (&dev->txq);
        skb_queue_head_init (&dev->done);
        dev->bh.func = usbnet_bh;
        dev->bh.data = (unsigned long) dev;
        INIT_WORK (&dev->kevent, kevent, dev);
        dev->delay.function = usbnet_bh;
        dev->delay.data = (unsigned long) dev;
        init_timer (&dev->delay);

        SET_MODULE_OWNER (net);
        dev->net = net;
        strcpy (net->name, "usb%d");
        memcpy (net->dev_addr, node_id, sizeof node_id);

#if 0
// dma_supported() is deeply broken on almost all architectures
        // possible with some EHCI controllers
        if (dma_supported (&udev->dev, 0xffffffffffffffffULL))
                net->features |= NETIF_F_HIGHDMA;
#endif

        net->change_mtu = usbnet_change_mtu;
        net->get_stats = usbnet_get_stats;
        net->hard_start_xmit = usbnet_start_xmit;
        net->open = usbnet_open;
        net->stop = usbnet_stop;
        net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
        net->tx_timeout = usbnet_tx_timeout;
        net->do_ioctl = usbnet_ioctl;
        net->ethtool_ops = &usbnet_ethtool_ops;

        // allow device-specific bind/init procedures
        // NOTE net->name still not usable ...
        if (info->bind) {
                status = info->bind (dev, udev);
                // heuristic:  "usb%d" for links we know are two-host,
                // else "eth%d" when there's reasonable doubt.  userspace
                // can rename the link if it knows better.
                if ((dev->driver_info->flags & FLAG_ETHER) != 0
                                && (net->dev_addr [0] & 0x02) == 0)
                        strcpy (net->name, "eth%d");
        } else if (!info->in || info->out)
                status = get_endpoints (dev, udev);
        else {
                dev->in = usb_rcvbulkpipe (xdev, info->in);
                dev->out = usb_sndbulkpipe (xdev, info->out);
                if (!(info->flags & FLAG_NO_SETINT))
                        status = usb_set_interface (xdev,
                                interface->desc.bInterfaceNumber,
                                interface->desc.bAlternateSetting);
                else
                        status = 0;

        }
        if (status < 0)
                goto out1;

        dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
        
        SET_NETDEV_DEV(net, &udev->dev);
        status = register_netdev (net);
        if (status)
                goto out3;
        devinfo (dev, "register usbnet at usb-%s-%s, %s",
                xdev->bus->bus_name, xdev->devpath,
                dev->driver_info->description);

        // ok, it's ready to go.
        usb_set_intfdata (udev, dev);

        // start as if the link is up
        netif_device_attach (net);

        return 0;

out3:
        if (info->unbind)
                info->unbind (dev, udev);
out1:
        free_netdev(net);
out:
        usb_put_dev(xdev);
        return status;
}


/*-------------------------------------------------------------------------*/

#ifndef HAVE_HARDWARE
#error You need to configure some hardware for this driver
#endif

/*
 * chip vendor names won't normally be on the cables, and
 * may not be on the device.
 */

static const struct usb_device_id       products [] = {

#ifdef  CONFIG_USB_ALI_M5632
{
        USB_DEVICE (0x0402, 0x5632),    // ALi defaults
        .driver_info =  (unsigned long) &ali_m5632_info,
},
#endif

#ifdef  CONFIG_USB_AN2720
{
        USB_DEVICE (0x0547, 0x2720),    // AnchorChips defaults
        .driver_info =  (unsigned long) &an2720_info,
}, {
        USB_DEVICE (0x0547, 0x2727),    // Xircom PGUNET
        .driver_info =  (unsigned long) &an2720_info,
},
#endif

#ifdef  CONFIG_USB_BELKIN
{
        USB_DEVICE (0x050d, 0x0004),    // Belkin
        .driver_info =  (unsigned long) &belkin_info,
}, {
        USB_DEVICE (0x056c, 0x8100),    // eTEK
        .driver_info =  (unsigned long) &belkin_info,
}, {
        USB_DEVICE (0x0525, 0x9901),    // Advance USBNET (eTEK)
        .driver_info =  (unsigned long) &belkin_info,
},
#endif

#ifdef CONFIG_USB_AX8817X
{
        // Linksys USB200M
        USB_DEVICE (0x077b, 0x2226),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // Netgear FA120
        USB_DEVICE (0x0846, 0x1040),
        .driver_info =  (unsigned long) &netgear_fa120_info,
}, {
        // DLink DUB-E100
        USB_DEVICE (0x2001, 0x1a00),
        .driver_info =  (unsigned long) &dlink_dub_e100_info,
}, {
        // Intellinet, ST Lab USB Ethernet
        USB_DEVICE (0x0b95, 0x1720),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // Hawking UF200, TrendNet TU2-ET100
        USB_DEVICE (0x07b8, 0x420a),
        .driver_info =  (unsigned long) &hawking_uf200_info,
}, {
        // Billionton Systems, USB2AR 
        USB_DEVICE (0x08dd, 0x90ff),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // ATEN UC210T
        USB_DEVICE (0x0557, 0x2009),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // Buffalo LUA-U2-KTX
        USB_DEVICE (0x0411, 0x003d),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // Sitecom LN-029 "USB 2.0 10/100 Ethernet adapter"
        USB_DEVICE (0x6189, 0x182d),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // corega FEther USB2-TX
        USB_DEVICE (0x07aa, 0x0017),
        .driver_info =  (unsigned long) &ax8817x_info,
}, {
        // Surecom EP-1427X-2
        USB_DEVICE (0x1189, 0x0893),
        .driver_info = (unsigned long) &ax8817x_info,
}, {
        // goodway corp usb gwusb2e
        USB_DEVICE (0x1631, 0x6200),
        .driver_info = (unsigned long) &ax8817x_info,
},
#endif

#ifdef  CONFIG_USB_EPSON2888
{
        USB_DEVICE (0x0525, 0x2888),    // EPSON USB client
        .driver_info    = (unsigned long) &epson2888_info,
},
#endif

#ifdef  CONFIG_USB_GENESYS
{
        USB_DEVICE (0x05e3, 0x0502),    // GL620USB-A
        .driver_info =  (unsigned long) &genelink_info,
},
        /* NOT: USB_DEVICE (0x05e3, 0x0501),    // GL620USB
         * that's half duplex, not currently supported
         */
#endif

#ifdef  CONFIG_USB_NET1080
{
        USB_DEVICE (0x0525, 0x1080),    // NetChip ref design
        .driver_info =  (unsigned long) &net1080_info,
}, {
        USB_DEVICE (0x06D0, 0x0622),    // Laplink Gold
        .driver_info =  (unsigned long) &net1080_info,
},
#endif

#ifdef CONFIG_USB_PL2301
{
        USB_DEVICE (0x067b, 0x0000),    // PL-2301
        .driver_info =  (unsigned long) &prolific_info,
}, {
        USB_DEVICE (0x067b, 0x0001),    // PL-2302
        .driver_info =  (unsigned long) &prolific_info,
},
#endif

#ifdef CONFIG_USB_KC2190
{
        USB_DEVICE (0x050f, 0x0190),    // KC-190
        .driver_info =  (unsigned long) &kc2190_info,
},
#endif

#ifdef  CONFIG_USB_RNDIS
{
        /* RNDIS is MSFT's un-official variant of CDC ACM */
        USB_INTERFACE_INFO (USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
        .driver_info = (unsigned long) &rndis_info,
},
#endif

#ifdef  CONFIG_USB_ARMLINUX
/*
 * SA-1100 using standard ARM Linux kernels, or compatible.
 * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
 * The sa-1100 "usb-eth" driver handles the basic framing.
 *
 * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
 * the sa1100 one, but hardware uses different endpoint numbers.
 *
 * Or the Linux "Ethernet" gadget on hardware that can't talk
 * CDC Ethernet (e.g., no altsettings), in either of two modes:
 *  - acting just like the old "usb-eth" firmware, though
 *    the implementation is different 
 *  - supporting RNDIS as the first/default configuration for
 *    MS-Windows interop; Linux needs to use the other config
 */
{
        // 1183 = 0x049F, both used as hex values?
        // Compaq "Itsy" vendor/product id
        USB_DEVICE (0x049F, 0x505A),    // usb-eth, or compatible
        .driver_info =  (unsigned long) &linuxdev_info,
}, {
        USB_DEVICE (0x0E7E, 0x1001),    // G.Mate "Yopy"
        .driver_info =  (unsigned long) &yopy_info,
}, {
        USB_DEVICE (0x8086, 0x07d3),    // "blob" bootloader
        .driver_info =  (unsigned long) &blob_info,
}, {
        // Linux Ethernet/RNDIS gadget on pxa210/25x/26x
        USB_DEVICE_VER (0x0525, 0xa4a2, 0x0203, 0x0203),
        .driver_info =  (unsigned long) &linuxdev_info,
}, 
#endif

#if     defined(CONFIG_USB_ZAURUS) || defined(CONFIG_USB_CDCETHER)
/*
 * SA-1100 based Sharp Zaurus ("collie"), or compatible.
 * Same idea as above, but different framing.
 *
 * PXA-2xx based models are also lying-about-cdc.
 *
 * NOTE:  These entries do double-duty, serving as blacklist entries
 * whenever Zaurus support isn't enabled, but CDC Ethernet is.
 */
{
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                          | USB_DEVICE_ID_MATCH_DEVICE, 
        .idVendor               = 0x04DD,
        .idProduct              = 0x8004,
        /* match the master interface */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0,
        .driver_info = ZAURUS_STRONGARM_INFO,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                          | USB_DEVICE_ID_MATCH_DEVICE, 
        .idVendor               = 0x04DD,
        .idProduct              = 0x8005,       /* A-300 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0x00,
        .driver_info = ZAURUS_PXA_INFO,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                          | USB_DEVICE_ID_MATCH_DEVICE, 
        .idVendor               = 0x04DD,
        .idProduct              = 0x8006,       /* B-500/SL-5600 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0x00,
        .driver_info = ZAURUS_PXA_INFO,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                  | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x8007,       /* C-700 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol = 0x00,
        .driver_info = ZAURUS_PXA_INFO,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x9031,       /* C-750 C-760 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0x00,
        .driver_info = ZAURUS_PXA_INFO,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x9032,       /* SL-6000 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0x00,
        .driver_info = ZAURUS_PXA_INFO,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x9050,       /* C-860 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0x00,
        .driver_info = ZAURUS_PXA_INFO,
},

/* Olympus has some models with a Zaurus-compatible option.
 * R-1000 uses a FreeScale i.MXL cpu (ARMv4T)
 */
{
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x07B4,
        .idProduct              = 0x0F02,       /* R-1000 */
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = 6 /* Ethernet model */,
        .bInterfaceProtocol     = 0x00,
        .driver_info = OLYMPUS_MXL_INFO,
},
#endif

#ifdef  CONFIG_USB_CDCETHER
{
        /* CDC Ether uses two interfaces, not necessarily consecutive.
         * We match the main interface, ignoring the optional device
         * class so we could handle devices that aren't exclusively
         * CDC ether.
         *
         * NOTE:  this match must come AFTER entries working around
         * bugs/quirks in a given product (like Zaurus, above).
         */
        USB_INTERFACE_INFO (USB_CLASS_COMM, 6 /* Ethernet model */, 0),
        .driver_info = (unsigned long) &cdc_info,
},
#endif

        { },            // END
};
MODULE_DEVICE_TABLE (usb, products);

static struct usb_driver usbnet_driver = {
        .owner =        THIS_MODULE,
        .name =         driver_name,
        .id_table =     products,
        .probe =        usbnet_probe,
        .disconnect =   usbnet_disconnect,
};

/* Default ethtool_ops assigned.  Devices can override in their bind() routine */
static struct ethtool_ops usbnet_ethtool_ops = {
        .get_drvinfo            = usbnet_get_drvinfo,
        .get_link               = usbnet_get_link,
        .get_msglevel           = usbnet_get_msglevel,
        .set_msglevel           = usbnet_set_msglevel,
};

/*-------------------------------------------------------------------------*/

static int __init usbnet_init (void)
{
        // compiler should optimize these out
        BUG_ON (sizeof (((struct sk_buff *)0)->cb)
                        < sizeof (struct skb_data));
#ifdef  CONFIG_USB_CDCETHER
        BUG_ON ((sizeof (((struct usbnet *)0)->data)
                        < sizeof (struct cdc_state)));
#endif

        random_ether_addr(node_id);

        return usb_register(&usbnet_driver);
}
module_init (usbnet_init);

static void __exit usbnet_exit (void)
{
        usb_deregister (&usbnet_driver);
}
module_exit (usbnet_exit);

MODULE_AUTHOR ("David Brownell <dbrownell@users.sourceforge.net>");
MODULE_DESCRIPTION ("USB Host-to-Host Link Drivers (numerous vendors)");
MODULE_LICENSE ("GPL");