// SPDX-License-Identifier: GPL-2.0-or-later
/****************************************************************
 *
 *     kaweth.c - driver for KL5KUSB101 based USB->Ethernet
 *
 *     (c) 2000 Interlan Communications
 *     (c) 2000 Stephane Alnet
 *     (C) 2001 Brad Hards
 *     (C) 2002 Oliver Neukum
 *
 *     Original author: The Zapman <zapman@interlan.net>
 *     Inspired by, and much credit goes to Michael Rothwell
 *     <rothwell@interlan.net> for the test equipment, help, and patience
 *     Based off of (and with thanks to) Petko Manolov's pegaus.c driver.
 *     Also many thanks to Joel Silverman and Ed Surprenant at Kawasaki
 *     for providing the firmware and driver resources.
 *
 ****************************************************************/

/* TODO:
 * Develop test procedures for USB net interfaces
 * Run test procedures
 * Fix bugs from previous two steps
 * Snoop other OSs for any tricks we're not doing
 * Reduce arbitrary timeouts
 * Smart multicast support
 * Temporary MAC change support
 * Tunable SOFs parameter - ioctl()?
 * Ethernet stats collection
 * Code formatting improvements
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/usb.h>
#include <linux/types.h>
#include <linux/ethtool.h>
#include <linux/dma-mapping.h>
#include <linux/wait.h>
#include <linux/firmware.h>
#include <linux/uaccess.h>
#include <asm/byteorder.h>

#undef DEBUG

#define KAWETH_MTU                      1514
#define KAWETH_BUF_SIZE                 1664
#define KAWETH_TX_TIMEOUT               (5 * HZ)
#define KAWETH_SCRATCH_SIZE             32
#define KAWETH_FIRMWARE_BUF_SIZE        4096
#define KAWETH_CONTROL_TIMEOUT          (30000)

#define KAWETH_STATUS_BROKEN            0x0000001
#define KAWETH_STATUS_CLOSING           0x0000002
#define KAWETH_STATUS_SUSPENDING        0x0000004

#define KAWETH_STATUS_BLOCKED (KAWETH_STATUS_CLOSING | KAWETH_STATUS_SUSPENDING)

#define KAWETH_PACKET_FILTER_PROMISCUOUS        0x01
#define KAWETH_PACKET_FILTER_ALL_MULTICAST      0x02
#define KAWETH_PACKET_FILTER_DIRECTED           0x04
#define KAWETH_PACKET_FILTER_BROADCAST          0x08
#define KAWETH_PACKET_FILTER_MULTICAST          0x10

/* Table 7 */
#define KAWETH_COMMAND_GET_ETHERNET_DESC        0x00
#define KAWETH_COMMAND_MULTICAST_FILTERS        0x01
#define KAWETH_COMMAND_SET_PACKET_FILTER        0x02
#define KAWETH_COMMAND_STATISTICS               0x03
#define KAWETH_COMMAND_SET_TEMP_MAC             0x06
#define KAWETH_COMMAND_GET_TEMP_MAC             0x07
#define KAWETH_COMMAND_SET_URB_SIZE             0x08
#define KAWETH_COMMAND_SET_SOFS_WAIT            0x09
#define KAWETH_COMMAND_SCAN                     0xFF

#define KAWETH_SOFS_TO_WAIT                     0x05

#define INTBUFFERSIZE                           4

#define STATE_OFFSET                            0
#define STATE_MASK                              0x40
#define STATE_SHIFT                             5

#define IS_BLOCKED(s) (s & KAWETH_STATUS_BLOCKED)


MODULE_AUTHOR("Michael Zappe <zapman@interlan.net>, Stephane Alnet <stephane@u-picardie.fr>, Brad Hards <bhards@bigpond.net.au> and Oliver Neukum <oliver@neukum.org>");
MODULE_DESCRIPTION("KL5USB101 USB Ethernet driver");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("kaweth/new_code.bin");
MODULE_FIRMWARE("kaweth/new_code_fix.bin");
MODULE_FIRMWARE("kaweth/trigger_code.bin");
MODULE_FIRMWARE("kaweth/trigger_code_fix.bin");

static const char driver_name[] = "kaweth";

static int kaweth_probe(
                struct usb_interface *intf,
                const struct usb_device_id *id  /* from id_table */
        );
static void kaweth_disconnect(struct usb_interface *intf);
static int kaweth_suspend(struct usb_interface *intf, pm_message_t message);
static int kaweth_resume(struct usb_interface *intf);

/****************************************************************
 *     usb_device_id
 ****************************************************************/
static const struct usb_device_id usb_klsi_table[] = {
        { USB_DEVICE(0x03e8, 0x0008) }, /* AOX Endpoints USB Ethernet */
        { USB_DEVICE(0x04bb, 0x0901) }, /* I-O DATA USB-ET/T */
        { USB_DEVICE(0x0506, 0x03e8) }, /* 3Com 3C19250 */
        { USB_DEVICE(0x0506, 0x11f8) }, /* 3Com 3C460 */
        { USB_DEVICE(0x0557, 0x2002) }, /* ATEN USB Ethernet */
        { USB_DEVICE(0x0557, 0x4000) }, /* D-Link DSB-650C */
        { USB_DEVICE(0x0565, 0x0002) }, /* Peracom Enet */
        { USB_DEVICE(0x0565, 0x0003) }, /* Optus@Home UEP1045A */
        { USB_DEVICE(0x0565, 0x0005) }, /* Peracom Enet2 */
        { USB_DEVICE(0x05e9, 0x0008) }, /* KLSI KL5KUSB101B */
        { USB_DEVICE(0x05e9, 0x0009) }, /* KLSI KL5KUSB101B (Board change) */
        { USB_DEVICE(0x066b, 0x2202) }, /* Linksys USB10T */
        { USB_DEVICE(0x06e1, 0x0008) }, /* ADS USB-10BT */
        { USB_DEVICE(0x06e1, 0x0009) }, /* ADS USB-10BT */
        { USB_DEVICE(0x0707, 0x0100) }, /* SMC 2202USB */
        { USB_DEVICE(0x07aa, 0x0001) }, /* Correga K.K. */
        { USB_DEVICE(0x07b8, 0x4000) }, /* D-Link DU-E10 */
        { USB_DEVICE(0x07c9, 0xb010) }, /* Allied Telesyn AT-USB10 USB Ethernet Adapter */
        { USB_DEVICE(0x0846, 0x1001) }, /* NetGear EA-101 */
        { USB_DEVICE(0x0846, 0x1002) }, /* NetGear EA-101 */
        { USB_DEVICE(0x085a, 0x0008) }, /* PortGear Ethernet Adapter */
        { USB_DEVICE(0x085a, 0x0009) }, /* PortGear Ethernet Adapter */
        { USB_DEVICE(0x087d, 0x5704) }, /* Jaton USB Ethernet Device Adapter */
        { USB_DEVICE(0x0951, 0x0008) }, /* Kingston Technology USB Ethernet Adapter */
        { USB_DEVICE(0x095a, 0x3003) }, /* Portsmith Express Ethernet Adapter */
        { USB_DEVICE(0x10bd, 0x1427) }, /* ASANTE USB To Ethernet Adapter */
        { USB_DEVICE(0x1342, 0x0204) }, /* Mobility USB-Ethernet Adapter */
        { USB_DEVICE(0x13d2, 0x0400) }, /* Shark Pocket Adapter */
        { USB_DEVICE(0x1485, 0x0001) }, /* Silicom U2E */
        { USB_DEVICE(0x1485, 0x0002) }, /* Psion Dacom Gold Port Ethernet */
        { USB_DEVICE(0x1645, 0x0005) }, /* Entrega E45 */
        { USB_DEVICE(0x1645, 0x0008) }, /* Entrega USB Ethernet Adapter */
        { USB_DEVICE(0x1645, 0x8005) }, /* PortGear Ethernet Adapter */
        { USB_DEVICE(0x1668, 0x0323) }, /* Actiontec USB Ethernet */
        { USB_DEVICE(0x2001, 0x4000) }, /* D-link DSB-650C */
        {} /* Null terminator */
};

MODULE_DEVICE_TABLE (usb, usb_klsi_table);

/****************************************************************
 *     kaweth_driver
 ****************************************************************/
static struct usb_driver kaweth_driver = {
        .name =         driver_name,
        .probe =        kaweth_probe,
        .disconnect =   kaweth_disconnect,
        .suspend =      kaweth_suspend,
        .resume =       kaweth_resume,
        .id_table =     usb_klsi_table,
        .supports_autosuspend = 1,
        .disable_hub_initiated_lpm = 1,
};

typedef __u8 eth_addr_t[6];

/****************************************************************
 *     usb_eth_dev
 ****************************************************************/
struct usb_eth_dev {
        char *name;
        __u16 vendor;
        __u16 device;
        void *pdata;
};

/****************************************************************
 *     kaweth_ethernet_configuration
 *     Refer Table 8
 ****************************************************************/
struct kaweth_ethernet_configuration
{
        __u8 size;
        __u8 reserved1;
        __u8 reserved2;
        eth_addr_t hw_addr;
        __u32 statistics_mask;
        __le16 segment_size;
        __u16 max_multicast_filters;
        __u8 reserved3;
} __packed;

/****************************************************************
 *     kaweth_device
 ****************************************************************/
struct kaweth_device
{
        spinlock_t device_lock;

        __u32 status;
        int end;
        int suspend_lowmem_rx;
        int suspend_lowmem_ctrl;
        int linkstate;
        int opened;
        struct delayed_work lowmem_work;

        struct usb_device *dev;
        struct usb_interface *intf;
        struct net_device *net;
        wait_queue_head_t term_wait;

        struct urb *rx_urb;
        struct urb *tx_urb;
        struct urb *irq_urb;

        dma_addr_t intbufferhandle;
        __u8 *intbuffer;
        dma_addr_t rxbufferhandle;
        __u8 *rx_buf;


        struct sk_buff *tx_skb;

        __u8 *firmware_buf;
        __u8 scratch[KAWETH_SCRATCH_SIZE];
        __u16 packet_filter_bitmap;

        struct kaweth_ethernet_configuration configuration;
};

/****************************************************************
 *     kaweth_read_configuration
 ****************************************************************/
static int kaweth_read_configuration(struct kaweth_device *kaweth)
{
        return usb_control_msg(kaweth->dev, usb_rcvctrlpipe(kaweth->dev, 0),
                                KAWETH_COMMAND_GET_ETHERNET_DESC,
                                USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
                                0, 0,
                                &kaweth->configuration,
                                sizeof(kaweth->configuration),
                                KAWETH_CONTROL_TIMEOUT);
}

/****************************************************************
 *     kaweth_set_urb_size
 ****************************************************************/
static int kaweth_set_urb_size(struct kaweth_device *kaweth, __u16 urb_size)
{
        netdev_dbg(kaweth->net, "Setting URB size to %d\n", (unsigned)urb_size);

        return usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
                               KAWETH_COMMAND_SET_URB_SIZE,
                               USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                               urb_size, 0,
                               &kaweth->scratch, 0,
                               KAWETH_CONTROL_TIMEOUT);
}

/****************************************************************
 *     kaweth_set_sofs_wait
 ****************************************************************/
static int kaweth_set_sofs_wait(struct kaweth_device *kaweth, __u16 sofs_wait)
{
        netdev_dbg(kaweth->net, "Set SOFS wait to %d\n", (unsigned)sofs_wait);

        return usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
                               KAWETH_COMMAND_SET_SOFS_WAIT,
                               USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                               sofs_wait, 0,
                               &kaweth->scratch, 0,
                               KAWETH_CONTROL_TIMEOUT);
}

/****************************************************************
 *     kaweth_set_receive_filter
 ****************************************************************/
static int kaweth_set_receive_filter(struct kaweth_device *kaweth,
                                     __u16 receive_filter)
{
        netdev_dbg(kaweth->net, "Set receive filter to %d\n",
                   (unsigned)receive_filter);

        return usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
                               KAWETH_COMMAND_SET_PACKET_FILTER,
                               USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                               receive_filter, 0,
                               &kaweth->scratch, 0,
                               KAWETH_CONTROL_TIMEOUT);
}

/****************************************************************
 *     kaweth_download_firmware
 ****************************************************************/
static int kaweth_download_firmware(struct kaweth_device *kaweth,
                                    const char *fwname,
                                    __u8 interrupt,
                                    __u8 type)
{
        const struct firmware *fw;
        int data_len;
        int ret;

        ret = request_firmware(&fw, fwname, &kaweth->dev->dev);
        if (ret) {
                dev_err(&kaweth->intf->dev, "Firmware request failed\n");
                return ret;
        }

        if (fw->size > KAWETH_FIRMWARE_BUF_SIZE) {
                dev_err(&kaweth->intf->dev, "Firmware too big: %zu\n",
                        fw->size);
                release_firmware(fw);
                return -ENOSPC;
        }
        data_len = fw->size;
        memcpy(kaweth->firmware_buf, fw->data, fw->size);

        release_firmware(fw);

        kaweth->firmware_buf[2] = (data_len & 0xFF) - 7;
        kaweth->firmware_buf[3] = data_len >> 8;
        kaweth->firmware_buf[4] = type;
        kaweth->firmware_buf[5] = interrupt;

        netdev_dbg(kaweth->net, "High: %i, Low:%i\n", kaweth->firmware_buf[3],
                   kaweth->firmware_buf[2]);

        netdev_dbg(kaweth->net,
                   "Downloading firmware at %p to kaweth device at %p\n",
                   kaweth->firmware_buf, kaweth);
        netdev_dbg(kaweth->net, "Firmware length: %d\n", data_len);

        return usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
                              KAWETH_COMMAND_SCAN,
                              USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                              0, 0,
                              kaweth->firmware_buf, data_len,
                              KAWETH_CONTROL_TIMEOUT);
}

/****************************************************************
 *     kaweth_trigger_firmware
 ****************************************************************/
static int kaweth_trigger_firmware(struct kaweth_device *kaweth,
                                   __u8 interrupt)
{
        kaweth->firmware_buf[0] = 0xB6;
        kaweth->firmware_buf[1] = 0xC3;
        kaweth->firmware_buf[2] = 0x01;
        kaweth->firmware_buf[3] = 0x00;
        kaweth->firmware_buf[4] = 0x06;
        kaweth->firmware_buf[5] = interrupt;
        kaweth->firmware_buf[6] = 0x00;
        kaweth->firmware_buf[7] = 0x00;

        return usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
                               KAWETH_COMMAND_SCAN,
                               USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                               0, 0,
                               (void *)kaweth->firmware_buf, 8,
                               KAWETH_CONTROL_TIMEOUT);
}

/****************************************************************
 *     kaweth_reset
 ****************************************************************/
static int kaweth_reset(struct kaweth_device *kaweth)
{
        int result;

        result = usb_reset_configuration(kaweth->dev);
        mdelay(10);

        netdev_dbg(kaweth->net, "kaweth_reset() returns %d.\n", result);

        return result;
}

static void kaweth_usb_receive(struct urb *);
static int kaweth_resubmit_rx_urb(struct kaweth_device *, gfp_t);

/****************************************************************
        int_callback
*****************************************************************/

static void kaweth_resubmit_int_urb(struct kaweth_device *kaweth, gfp_t mf)
{
        int status;

        status = usb_submit_urb (kaweth->irq_urb, mf);
        if (unlikely(status == -ENOMEM)) {
                kaweth->suspend_lowmem_ctrl = 1;
                schedule_delayed_work(&kaweth->lowmem_work, HZ/4);
        } else {
                kaweth->suspend_lowmem_ctrl = 0;
        }

        if (status)
                dev_err(&kaweth->intf->dev,
                        "can't resubmit intr, %s-%s, status %d\n",
                        kaweth->dev->bus->bus_name,
                        kaweth->dev->devpath, status);
}

static void int_callback(struct urb *u)
{
        struct kaweth_device *kaweth = u->context;
        int act_state;
        int status = u->status;

        switch (status) {
        case 0:                 /* success */
                break;
        case -ECONNRESET:       /* unlink */
        case -ENOENT:
        case -ESHUTDOWN:
                return;
        /* -EPIPE:  should clear the halt */
        default:                /* error */
                goto resubmit;
        }

        /* we check the link state to report changes */
        if (kaweth->linkstate != (act_state = ( kaweth->intbuffer[STATE_OFFSET] | STATE_MASK) >> STATE_SHIFT)) {
                if (act_state)
                        netif_carrier_on(kaweth->net);
                else
                        netif_carrier_off(kaweth->net);

                kaweth->linkstate = act_state;
        }
resubmit:
        kaweth_resubmit_int_urb(kaweth, GFP_ATOMIC);
}

static void kaweth_resubmit_tl(struct work_struct *work)
{
        struct kaweth_device *kaweth =
                container_of(work, struct kaweth_device, lowmem_work.work);

        if (IS_BLOCKED(kaweth->status))
                return;

        if (kaweth->suspend_lowmem_rx)
                kaweth_resubmit_rx_urb(kaweth, GFP_NOIO);

        if (kaweth->suspend_lowmem_ctrl)
                kaweth_resubmit_int_urb(kaweth, GFP_NOIO);
}


/****************************************************************
 *     kaweth_resubmit_rx_urb
 ****************************************************************/
static int kaweth_resubmit_rx_urb(struct kaweth_device *kaweth,
                                                gfp_t mem_flags)
{
        int result;

        usb_fill_bulk_urb(kaweth->rx_urb,
                      kaweth->dev,
                      usb_rcvbulkpipe(kaweth->dev, 1),
                      kaweth->rx_buf,
                      KAWETH_BUF_SIZE,
                      kaweth_usb_receive,
                      kaweth);
        kaweth->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
        kaweth->rx_urb->transfer_dma = kaweth->rxbufferhandle;

        if((result = usb_submit_urb(kaweth->rx_urb, mem_flags))) {
                if (result == -ENOMEM) {
                        kaweth->suspend_lowmem_rx = 1;
                        schedule_delayed_work(&kaweth->lowmem_work, HZ/4);
                }
                dev_err(&kaweth->intf->dev, "resubmitting rx_urb %d failed\n",
                        result);
        } else {
                kaweth->suspend_lowmem_rx = 0;
        }

        return result;
}

static void kaweth_async_set_rx_mode(struct kaweth_device *kaweth,
                                     bool may_sleep);

/****************************************************************
 *     kaweth_usb_receive
 ****************************************************************/
static void kaweth_usb_receive(struct urb *urb)
{
        struct device *dev = &urb->dev->dev;
        struct kaweth_device *kaweth = urb->context;
        struct net_device *net = kaweth->net;
        int status = urb->status;
        unsigned long flags;
        int count = urb->actual_length;
        int count2 = urb->transfer_buffer_length;

        __u16 pkt_len = le16_to_cpup((__le16 *)kaweth->rx_buf);

        struct sk_buff *skb;

        if (unlikely(status == -EPIPE)) {
                net->stats.rx_errors++;
                kaweth->end = 1;
                wake_up(&kaweth->term_wait);
                dev_dbg(dev, "Status was -EPIPE.\n");
                return;
        }
        if (unlikely(status == -ECONNRESET || status == -ESHUTDOWN)) {
                /* we are killed - set a flag and wake the disconnect handler */
                kaweth->end = 1;
                wake_up(&kaweth->term_wait);
                dev_dbg(dev, "Status was -ECONNRESET or -ESHUTDOWN.\n");
                return;
        }
        if (unlikely(status == -EPROTO || status == -ETIME ||
                     status == -EILSEQ)) {
                net->stats.rx_errors++;
                dev_dbg(dev, "Status was -EPROTO, -ETIME, or -EILSEQ.\n");
                return;
        }
        if (unlikely(status == -EOVERFLOW)) {
                net->stats.rx_errors++;
                dev_dbg(dev, "Status was -EOVERFLOW.\n");
        }
        spin_lock_irqsave(&kaweth->device_lock, flags);
        if (IS_BLOCKED(kaweth->status)) {
                spin_unlock_irqrestore(&kaweth->device_lock, flags);
                return;
        }
        spin_unlock_irqrestore(&kaweth->device_lock, flags);

        if(status && status != -EREMOTEIO && count != 1) {
                dev_err(&kaweth->intf->dev,
                        "%s RX status: %d count: %d packet_len: %d\n",
                        net->name, status, count, (int)pkt_len);
                kaweth_resubmit_rx_urb(kaweth, GFP_ATOMIC);
                return;
        }

        if(kaweth->net && (count > 2)) {
                if(pkt_len > (count - 2)) {
                        dev_err(&kaweth->intf->dev,
                                "Packet length too long for USB frame (pkt_len: %x, count: %x)\n",
                                pkt_len, count);
                        dev_err(&kaweth->intf->dev, "Packet len & 2047: %x\n",
                                pkt_len & 2047);
                        dev_err(&kaweth->intf->dev, "Count 2: %x\n", count2);
                        kaweth_resubmit_rx_urb(kaweth, GFP_ATOMIC);
                        return;
                }

                if(!(skb = dev_alloc_skb(pkt_len+2))) {
                        kaweth_resubmit_rx_urb(kaweth, GFP_ATOMIC);
                        return;
                }

                skb_reserve(skb, 2);    /* Align IP on 16 byte boundaries */

                skb_copy_to_linear_data(skb, kaweth->rx_buf + 2, pkt_len);

                skb_put(skb, pkt_len);

                skb->protocol = eth_type_trans(skb, net);

                netif_rx(skb);

                net->stats.rx_packets++;
                net->stats.rx_bytes += pkt_len;
        }

        kaweth_resubmit_rx_urb(kaweth, GFP_ATOMIC);
}

/****************************************************************
 *     kaweth_open
 ****************************************************************/
static int kaweth_open(struct net_device *net)
{
        struct kaweth_device *kaweth = netdev_priv(net);
        int res;

        res = usb_autopm_get_interface(kaweth->intf);
        if (res) {
                dev_err(&kaweth->intf->dev, "Interface cannot be resumed.\n");
                return -EIO;
        }
        res = kaweth_resubmit_rx_urb(kaweth, GFP_KERNEL);
        if (res)
                goto err_out;

        usb_fill_int_urb(
                kaweth->irq_urb,
                kaweth->dev,
                usb_rcvintpipe(kaweth->dev, 3),
                kaweth->intbuffer,
                INTBUFFERSIZE,
                int_callback,
                kaweth,
                250); /* overriding the descriptor */
        kaweth->irq_urb->transfer_dma = kaweth->intbufferhandle;
        kaweth->irq_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

        res = usb_submit_urb(kaweth->irq_urb, GFP_KERNEL);
        if (res) {
                usb_kill_urb(kaweth->rx_urb);
                goto err_out;
        }
        kaweth->opened = 1;

        netif_start_queue(net);

        kaweth_async_set_rx_mode(kaweth, true);
        return 0;

err_out:
        usb_autopm_put_interface(kaweth->intf);
        return -EIO;
}

/****************************************************************
 *     kaweth_kill_urbs
 ****************************************************************/
static void kaweth_kill_urbs(struct kaweth_device *kaweth)
{
        usb_kill_urb(kaweth->irq_urb);
        usb_kill_urb(kaweth->rx_urb);
        usb_kill_urb(kaweth->tx_urb);

        cancel_delayed_work_sync(&kaweth->lowmem_work);

        /* a scheduled work may have resubmitted,
           we hit them again */
        usb_kill_urb(kaweth->irq_urb);
        usb_kill_urb(kaweth->rx_urb);
}

/****************************************************************
 *     kaweth_close
 ****************************************************************/
static int kaweth_close(struct net_device *net)
{
        struct kaweth_device *kaweth = netdev_priv(net);

        netif_stop_queue(net);
        kaweth->opened = 0;

        kaweth->status |= KAWETH_STATUS_CLOSING;

        kaweth_kill_urbs(kaweth);

        kaweth->status &= ~KAWETH_STATUS_CLOSING;

        usb_autopm_put_interface(kaweth->intf);

        return 0;
}

static u32 kaweth_get_link(struct net_device *dev)
{
        struct kaweth_device *kaweth = netdev_priv(dev);

        return kaweth->linkstate;
}

static const struct ethtool_ops ops = {
        .get_link       = kaweth_get_link
};

/****************************************************************
 *     kaweth_usb_transmit_complete
 ****************************************************************/
static void kaweth_usb_transmit_complete(struct urb *urb)
{
        struct kaweth_device *kaweth = urb->context;
        struct sk_buff *skb = kaweth->tx_skb;
        int status = urb->status;

        if (unlikely(status != 0))
                if (status != -ENOENT)
                        dev_dbg(&urb->dev->dev, "%s: TX status %d.\n",
                                kaweth->net->name, status);

        netif_wake_queue(kaweth->net);
        dev_kfree_skb_irq(skb);
}

/****************************************************************
 *     kaweth_start_xmit
 ****************************************************************/
static netdev_tx_t kaweth_start_xmit(struct sk_buff *skb,
                                           struct net_device *net)
{
        struct kaweth_device *kaweth = netdev_priv(net);
        __le16 *private_header;

        int res;

        spin_lock_irq(&kaweth->device_lock);

        kaweth_async_set_rx_mode(kaweth, false);
        netif_stop_queue(net);
        if (IS_BLOCKED(kaweth->status)) {
                goto skip;
        }

        /* We now decide whether we can put our special header into the sk_buff */
        if (skb_cow_head(skb, 2)) {
                net->stats.tx_errors++;
                netif_start_queue(net);
                spin_unlock_irq(&kaweth->device_lock);
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        private_header = __skb_push(skb, 2);
        *private_header = cpu_to_le16(skb->len-2);
        kaweth->tx_skb = skb;

        usb_fill_bulk_urb(kaweth->tx_urb,
                      kaweth->dev,
                      usb_sndbulkpipe(kaweth->dev, 2),
                      private_header,
                      skb->len,
                      kaweth_usb_transmit_complete,
                      kaweth);
        kaweth->end = 0;

        if((res = usb_submit_urb(kaweth->tx_urb, GFP_ATOMIC)))
        {
                dev_warn(&net->dev, "kaweth failed tx_urb %d\n", res);
skip:
                net->stats.tx_errors++;

                netif_start_queue(net);
                dev_kfree_skb_irq(skb);
        }
        else
        {
                net->stats.tx_packets++;
                net->stats.tx_bytes += skb->len;
        }

        spin_unlock_irq(&kaweth->device_lock);

        return NETDEV_TX_OK;
}

/****************************************************************
 *     kaweth_set_rx_mode
 ****************************************************************/
static void kaweth_set_rx_mode(struct net_device *net)
{
        struct kaweth_device *kaweth = netdev_priv(net);

        __u16 packet_filter_bitmap = KAWETH_PACKET_FILTER_DIRECTED |
                                     KAWETH_PACKET_FILTER_BROADCAST |
                                     KAWETH_PACKET_FILTER_MULTICAST;

        netdev_dbg(net, "Setting Rx mode to %d\n", packet_filter_bitmap);


        if (net->flags & IFF_PROMISC) {
                packet_filter_bitmap |= KAWETH_PACKET_FILTER_PROMISCUOUS;
        }
        else if (!netdev_mc_empty(net) || (net->flags & IFF_ALLMULTI)) {
                packet_filter_bitmap |= KAWETH_PACKET_FILTER_ALL_MULTICAST;
        }

        kaweth->packet_filter_bitmap = packet_filter_bitmap;
}

/****************************************************************
 *     kaweth_async_set_rx_mode
 ****************************************************************/
static void kaweth_async_set_rx_mode(struct kaweth_device *kaweth,
                                     bool may_sleep)
{
        int ret;
        __u16 packet_filter_bitmap = kaweth->packet_filter_bitmap;

        kaweth->packet_filter_bitmap = 0;
        if (packet_filter_bitmap == 0)
                return;

        if (!may_sleep)
                return;

        ret = usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
                              KAWETH_COMMAND_SET_PACKET_FILTER,
                              USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                              packet_filter_bitmap, 0,
                              &kaweth->scratch, 0,
                              KAWETH_CONTROL_TIMEOUT);
        if (ret < 0)
                dev_err(&kaweth->intf->dev, "Failed to set Rx mode: %d\n",
                        ret);
        else
                netdev_dbg(kaweth->net, "Set Rx mode to %d\n",
                           packet_filter_bitmap);
}

/****************************************************************
 *     kaweth_tx_timeout
 ****************************************************************/
static void kaweth_tx_timeout(struct net_device *net, unsigned int txqueue)
{
        struct kaweth_device *kaweth = netdev_priv(net);

        dev_warn(&net->dev, "%s: Tx timed out. Resetting.\n", net->name);
        net->stats.tx_errors++;
        netif_trans_update(net);

        usb_unlink_urb(kaweth->tx_urb);
}

/****************************************************************
 *     kaweth_suspend
 ****************************************************************/
static int kaweth_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct kaweth_device *kaweth = usb_get_intfdata(intf);
        unsigned long flags;

        spin_lock_irqsave(&kaweth->device_lock, flags);
        kaweth->status |= KAWETH_STATUS_SUSPENDING;
        spin_unlock_irqrestore(&kaweth->device_lock, flags);

        kaweth_kill_urbs(kaweth);
        return 0;
}

/****************************************************************
 *     kaweth_resume
 ****************************************************************/
static int kaweth_resume(struct usb_interface *intf)
{
        struct kaweth_device *kaweth = usb_get_intfdata(intf);
        unsigned long flags;

        spin_lock_irqsave(&kaweth->device_lock, flags);
        kaweth->status &= ~KAWETH_STATUS_SUSPENDING;
        spin_unlock_irqrestore(&kaweth->device_lock, flags);

        if (!kaweth->opened)
                return 0;
        kaweth_resubmit_rx_urb(kaweth, GFP_NOIO);
        kaweth_resubmit_int_urb(kaweth, GFP_NOIO);

        return 0;
}

/****************************************************************
 *     kaweth_probe
 ****************************************************************/


static const struct net_device_ops kaweth_netdev_ops = {
        .ndo_open =                     kaweth_open,
        .ndo_stop =                     kaweth_close,
        .ndo_start_xmit =               kaweth_start_xmit,
        .ndo_tx_timeout =               kaweth_tx_timeout,
        .ndo_set_rx_mode =              kaweth_set_rx_mode,
        .ndo_set_mac_address =          eth_mac_addr,
        .ndo_validate_addr =            eth_validate_addr,
};

static int kaweth_probe(
                struct usb_interface *intf,
                const struct usb_device_id *id      /* from id_table */
        )
{
        struct device *dev = &intf->dev;
        struct usb_device *udev = interface_to_usbdev(intf);
        struct kaweth_device *kaweth;
        struct net_device *netdev;
        const eth_addr_t bcast_addr = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
        int result = 0;
        int rv = -EIO;
        static const u8 bulk_ep_addr[] = {
                1 | USB_DIR_IN,
                2 | USB_DIR_OUT,
                0};
        static const u8 int_ep_addr[] = {
                3 | USB_DIR_IN,
                0};

        dev_dbg(dev,
                "Kawasaki Device Probe (Device number:%d): 0x%4.4x:0x%4.4x:0x%4.4x\n",
                udev->devnum, le16_to_cpu(udev->descriptor.idVendor),
                le16_to_cpu(udev->descriptor.idProduct),
                le16_to_cpu(udev->descriptor.bcdDevice));

        dev_dbg(dev, "Device at %p\n", udev);

        dev_dbg(dev, "Descriptor length: %x type: %x\n",
                (int)udev->descriptor.bLength,
                (int)udev->descriptor.bDescriptorType);

        if (!usb_check_bulk_endpoints(intf, bulk_ep_addr) ||
            !usb_check_int_endpoints(intf, int_ep_addr)) {
                dev_err(dev, "couldn't find required endpoints\n");
                return -ENODEV;
        }

        netdev = alloc_etherdev(sizeof(*kaweth));
        if (!netdev)
                return -ENOMEM;

        kaweth = netdev_priv(netdev);
        kaweth->dev = udev;
        kaweth->net = netdev;
        kaweth->intf = intf;

        spin_lock_init(&kaweth->device_lock);
        init_waitqueue_head(&kaweth->term_wait);

        dev_dbg(dev, "Resetting.\n");

        kaweth_reset(kaweth);

        /*
         * If high byte of bcdDevice is nonzero, firmware is already
         * downloaded. Don't try to do it again, or we'll hang the device.
         */

        if (le16_to_cpu(udev->descriptor.bcdDevice) >> 8) {
                dev_info(dev, "Firmware present in device.\n");
        } else {
                /* Download the firmware */
                dev_info(dev, "Downloading firmware...\n");
                kaweth->firmware_buf = (__u8 *)__get_free_page(GFP_KERNEL);
                if (!kaweth->firmware_buf) {
                        rv = -ENOMEM;
                        goto err_free_netdev;
                }
                if ((result = kaweth_download_firmware(kaweth,
                                                      "kaweth/new_code.bin",
                                                      100,
                                                      2)) < 0) {
                        dev_err(dev, "Error downloading firmware (%d)\n",
                                result);
                        goto err_fw;
                }

                if ((result = kaweth_download_firmware(kaweth,
                                                      "kaweth/new_code_fix.bin",
                                                      100,
                                                      3)) < 0) {
                        dev_err(dev, "Error downloading firmware fix (%d)\n",
                                result);
                        goto err_fw;
                }

                if ((result = kaweth_download_firmware(kaweth,
                                                      "kaweth/trigger_code.bin",
                                                      126,
                                                      2)) < 0) {
                        dev_err(dev, "Error downloading trigger code (%d)\n",
                                result);
                        goto err_fw;

                }

                if ((result = kaweth_download_firmware(kaweth,
                                                      "kaweth/trigger_code_fix.bin",
                                                      126,
                                                      3)) < 0) {
                        dev_err(dev, "Error downloading trigger code fix (%d)\n", result);
                        goto err_fw;
                }


                if ((result = kaweth_trigger_firmware(kaweth, 126)) < 0) {
                        dev_err(dev, "Error triggering firmware (%d)\n", result);
                        goto err_fw;
                }

                /* Device will now disappear for a moment...  */
                dev_info(dev, "Firmware loaded.  I'll be back...\n");
err_fw:
                free_page((unsigned long)kaweth->firmware_buf);
                free_netdev(netdev);
                return -EIO;
        }

        result = kaweth_read_configuration(kaweth);

        if(result < 0) {
                dev_err(dev, "Error reading configuration (%d), no net device created\n", result);
                goto err_free_netdev;
        }

        dev_info(dev, "Statistics collection: %x\n", kaweth->configuration.statistics_mask);
        dev_info(dev, "Multicast filter limit: %x\n", kaweth->configuration.max_multicast_filters & ((1 << 15) - 1));
        dev_info(dev, "MTU: %d\n", le16_to_cpu(kaweth->configuration.segment_size));
        dev_info(dev, "Read MAC address %pM\n", kaweth->configuration.hw_addr);

        if(!memcmp(&kaweth->configuration.hw_addr,
                   &bcast_addr,
                   sizeof(bcast_addr))) {
                dev_err(dev, "Firmware not functioning properly, no net device created\n");
                goto err_free_netdev;
        }

        if(kaweth_set_urb_size(kaweth, KAWETH_BUF_SIZE) < 0) {
                dev_dbg(dev, "Error setting URB size\n");
                goto err_free_netdev;
        }

        if(kaweth_set_sofs_wait(kaweth, KAWETH_SOFS_TO_WAIT) < 0) {
                dev_err(dev, "Error setting SOFS wait\n");
                goto err_free_netdev;
        }

        result = kaweth_set_receive_filter(kaweth,
                                           KAWETH_PACKET_FILTER_DIRECTED |
                                           KAWETH_PACKET_FILTER_BROADCAST |
                                           KAWETH_PACKET_FILTER_MULTICAST);

        if(result < 0) {
                dev_err(dev, "Error setting receive filter\n");
                goto err_free_netdev;
        }

        dev_dbg(dev, "Initializing net device.\n");

        kaweth->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!kaweth->tx_urb)
                goto err_free_netdev;
        kaweth->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!kaweth->rx_urb)
                goto err_only_tx;
        kaweth->irq_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!kaweth->irq_urb)
                goto err_tx_and_rx;

        kaweth->intbuffer = usb_alloc_coherent( kaweth->dev,
                                                INTBUFFERSIZE,
                                                GFP_KERNEL,
                                                &kaweth->intbufferhandle);
        if (!kaweth->intbuffer)
                goto err_tx_and_rx_and_irq;
        kaweth->rx_buf = usb_alloc_coherent(    kaweth->dev,
                                                KAWETH_BUF_SIZE,
                                                GFP_KERNEL,
                                                &kaweth->rxbufferhandle);
        if (!kaweth->rx_buf)
                goto err_all_but_rxbuf;

        memcpy(netdev->broadcast, &bcast_addr, sizeof(bcast_addr));
        eth_hw_addr_set(netdev, (u8 *)&kaweth->configuration.hw_addr);

        netdev->netdev_ops = &kaweth_netdev_ops;
        netdev->watchdog_timeo = KAWETH_TX_TIMEOUT;
        netdev->mtu = le16_to_cpu(kaweth->configuration.segment_size);
        netdev->ethtool_ops = &ops;

        /* kaweth is zeroed as part of alloc_netdev */
        INIT_DELAYED_WORK(&kaweth->lowmem_work, kaweth_resubmit_tl);
        usb_set_intfdata(intf, kaweth);

        SET_NETDEV_DEV(netdev, dev);
        if (register_netdev(netdev) != 0) {
                dev_err(dev, "Error registering netdev.\n");
                goto err_intfdata;
        }

        dev_info(dev, "kaweth interface created at %s\n",
                 kaweth->net->name);

        return 0;

err_intfdata:
        usb_set_intfdata(intf, NULL);
        usb_free_coherent(kaweth->dev, KAWETH_BUF_SIZE, (void *)kaweth->rx_buf, kaweth->rxbufferhandle);
err_all_but_rxbuf:
        usb_free_coherent(kaweth->dev, INTBUFFERSIZE, (void *)kaweth->intbuffer, kaweth->intbufferhandle);
err_tx_and_rx_and_irq:
        usb_free_urb(kaweth->irq_urb);
err_tx_and_rx:
        usb_free_urb(kaweth->rx_urb);
err_only_tx:
        usb_free_urb(kaweth->tx_urb);
err_free_netdev:
        free_netdev(netdev);

        return rv;
}

/****************************************************************
 *     kaweth_disconnect
 ****************************************************************/
static void kaweth_disconnect(struct usb_interface *intf)
{
        struct kaweth_device *kaweth = usb_get_intfdata(intf);
        struct net_device *netdev;

        usb_set_intfdata(intf, NULL);
        if (!kaweth) {
                dev_warn(&intf->dev, "unregistering non-existent device\n");
                return;
        }
        netdev = kaweth->net;

        netdev_dbg(kaweth->net, "Unregistering net device\n");
        unregister_netdev(netdev);

        usb_free_urb(kaweth->rx_urb);
        usb_free_urb(kaweth->tx_urb);
        usb_free_urb(kaweth->irq_urb);

        usb_free_coherent(kaweth->dev, KAWETH_BUF_SIZE, (void *)kaweth->rx_buf, kaweth->rxbufferhandle);
        usb_free_coherent(kaweth->dev, INTBUFFERSIZE, (void *)kaweth->intbuffer, kaweth->intbufferhandle);

        free_netdev(netdev);
}


module_usb_driver(kaweth_driver);