cdc_ncm.c

Go to the documentation of this file.

/*
 * cdc_ncm.c
 *
 * Copyright (C) ST-Ericsson 2010-2012
 * Contact: Alexey Orishko <[email protected]>
 * Original author: Hans Petter Selasky <[email protected]>
 *
 * USB Host Driver for Network Control Model (NCM)
 * http://www.usb.org/developers/devclass_docs/NCM10.zip
 *
 * The NCM encoding, decoding and initialization logic
 * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
 *
 * This software is available to you under a choice of one of two
 * licenses. You may choose this file to be licensed under the terms
 * of the GNU General Public License (GPL) Version 2 or the 2-clause
 * BSD license listed below:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/ctype.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/crc32.h>
#include <linux/usb.h>
#include <linux/hrtimer.h>
#include <linux/atomic.h>
#include <linux/usb/usbnet.h>
#include <linux/usb/cdc.h>

#define DRIVER_VERSION              "14-Mar-2012"

/* CDC NCM subclass 3.2.1 */
#define USB_CDC_NCM_NDP16_LENGTH_MIN        0x10

/* Maximum NTB length */
#define CDC_NCM_NTB_MAX_SIZE_TX         32768   /* bytes */
#define CDC_NCM_NTB_MAX_SIZE_RX         32768   /* bytes */

/* Minimum value for MaxDatagramSize, ch. 6.2.9 */
#define CDC_NCM_MIN_DATAGRAM_SIZE       1514    /* bytes */

#define CDC_NCM_MIN_TX_PKT          512 /* bytes */

/* Default value for MaxDatagramSize */
#define CDC_NCM_MAX_DATAGRAM_SIZE       8192    /* bytes */

/*
 * Maximum amount of datagrams in NCM Datagram Pointer Table, not counting
 * the last NULL entry.
 */
#define CDC_NCM_DPT_DATAGRAMS_MAX       40

/* Restart the timer, if amount of datagrams is less than given value */
#define CDC_NCM_RESTART_TIMER_DATAGRAM_CNT  3
#define CDC_NCM_TIMER_PENDING_CNT       2
#define CDC_NCM_TIMER_INTERVAL          (400UL * NSEC_PER_USEC)

/* The following macro defines the minimum header space */
#define CDC_NCM_MIN_HDR_SIZE \
    (sizeof(struct usb_cdc_ncm_nth16) + sizeof(struct usb_cdc_ncm_ndp16) + \
    (CDC_NCM_DPT_DATAGRAMS_MAX + 1) * sizeof(struct usb_cdc_ncm_dpe16))

struct cdc_ncm_data {
    struct usb_cdc_ncm_nth16 nth16;
    struct usb_cdc_ncm_ndp16 ndp16;
    struct usb_cdc_ncm_dpe16 dpe16[CDC_NCM_DPT_DATAGRAMS_MAX + 1];
};

struct cdc_ncm_ctx {
    struct cdc_ncm_data tx_ncm;
    struct usb_cdc_ncm_ntb_parameters ncm_parm;
    struct hrtimer tx_timer;
    struct tasklet_struct bh;

    const struct usb_cdc_ncm_desc *func_desc;
    const struct usb_cdc_header_desc *header_desc;
    const struct usb_cdc_union_desc *union_desc;
    const struct usb_cdc_ether_desc *ether_desc;

    struct net_device *netdev;
    struct usb_device *udev;
    struct usb_host_endpoint *in_ep;
    struct usb_host_endpoint *out_ep;
    struct usb_host_endpoint *status_ep;
    struct usb_interface *intf;
    struct usb_interface *control;
    struct usb_interface *data;

    struct sk_buff *tx_curr_skb;
    struct sk_buff *tx_rem_skb;

    spinlock_t mtx;
    atomic_t stop;

    u32 tx_timer_pending;
    u32 tx_curr_offset;
    u32 tx_curr_last_offset;
    u32 tx_curr_frame_num;
    u32 rx_speed;
    u32 tx_speed;
    u32 rx_max;
    u32 tx_max;
    u32 max_datagram_size;
    u16 tx_max_datagrams;
    u16 tx_remainder;
    u16 tx_modulus;
    u16 tx_ndp_modulus;
    u16 tx_seq;
    u16 rx_seq;
    u16 connected;
};

static void cdc_ncm_txpath_bh(unsigned long param);
static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
static struct usb_driver cdc_ncm_driver;

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

    strncpy(info->driver, dev->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 u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx)
{
    u32 val;
    u8 flags;
    u8 iface_no;
    int err;
    u16 ntb_fmt_supported;

    iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;

    err = usb_control_msg(ctx->udev,
                usb_rcvctrlpipe(ctx->udev, 0),
                USB_CDC_GET_NTB_PARAMETERS,
                USB_TYPE_CLASS | USB_DIR_IN
                 | USB_RECIP_INTERFACE,
                0, iface_no, &ctx->ncm_parm,
                sizeof(ctx->ncm_parm), 10000);
    if (err < 0) {
        pr_debug("failed GET_NTB_PARAMETERS\n");
        return 1;
    }

    /* read correct set of parameters according to device mode */
    ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
    ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
    ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
    ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
    ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
    /* devices prior to NCM Errata shall set this field to zero */
    ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
    ntb_fmt_supported = le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported);

    if (ctx->func_desc != NULL)
        flags = ctx->func_desc->bmNetworkCapabilities;
    else
        flags = 0;

    pr_debug("dwNtbInMaxSize=%u dwNtbOutMaxSize=%u "
         "wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u "
         "wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
         ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
         ctx->tx_ndp_modulus, ctx->tx_max_datagrams, flags);

    /* max count of tx datagrams */
    if ((ctx->tx_max_datagrams == 0) ||
            (ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
        ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;

    /* verify maximum size of received NTB in bytes */
    if (ctx->rx_max < USB_CDC_NCM_NTB_MIN_IN_SIZE) {
        pr_debug("Using min receive length=%d\n",
                        USB_CDC_NCM_NTB_MIN_IN_SIZE);
        ctx->rx_max = USB_CDC_NCM_NTB_MIN_IN_SIZE;
    }

    if (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX) {
        pr_debug("Using default maximum receive length=%d\n",
                        CDC_NCM_NTB_MAX_SIZE_RX);
        ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
    }

    /* inform device about NTB input size changes */
    if (ctx->rx_max != le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize)) {

        if (flags & USB_CDC_NCM_NCAP_NTB_INPUT_SIZE) {
            struct usb_cdc_ncm_ndp_input_size *ndp_in_sz;

            ndp_in_sz = kzalloc(sizeof(*ndp_in_sz), GFP_KERNEL);
            if (!ndp_in_sz) {
                err = -ENOMEM;
                goto size_err;
            }

            err = usb_control_msg(ctx->udev,
                    usb_sndctrlpipe(ctx->udev, 0),
                    USB_CDC_SET_NTB_INPUT_SIZE,
                    USB_TYPE_CLASS | USB_DIR_OUT
                     | USB_RECIP_INTERFACE,
                    0, iface_no, ndp_in_sz, 8, 1000);
            kfree(ndp_in_sz);
        } else {
            __le32 *dwNtbInMaxSize;
            dwNtbInMaxSize = kzalloc(sizeof(*dwNtbInMaxSize),
                    GFP_KERNEL);
            if (!dwNtbInMaxSize) {
                err = -ENOMEM;
                goto size_err;
            }
            *dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);

            err = usb_control_msg(ctx->udev,
                    usb_sndctrlpipe(ctx->udev, 0),
                    USB_CDC_SET_NTB_INPUT_SIZE,
                    USB_TYPE_CLASS | USB_DIR_OUT
                     | USB_RECIP_INTERFACE,
                    0, iface_no, dwNtbInMaxSize, 4, 1000);
            kfree(dwNtbInMaxSize);
        }
size_err:
        if (err < 0)
            pr_debug("Setting NTB Input Size failed\n");
    }

    /* verify maximum size of transmitted NTB in bytes */
    if ((ctx->tx_max <
        (CDC_NCM_MIN_HDR_SIZE + CDC_NCM_MIN_DATAGRAM_SIZE)) ||
        (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX)) {
        pr_debug("Using default maximum transmit length=%d\n",
                        CDC_NCM_NTB_MAX_SIZE_TX);
        ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
    }

    /*
     * verify that the structure alignment is:
     * - power of two
     * - not greater than the maximum transmit length
     * - not less than four bytes
     */
    val = ctx->tx_ndp_modulus;

    if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
        (val != ((-val) & val)) || (val >= ctx->tx_max)) {
        pr_debug("Using default alignment: 4 bytes\n");
        ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
    }

    /*
     * verify that the payload alignment is:
     * - power of two
     * - not greater than the maximum transmit length
     * - not less than four bytes
     */
    val = ctx->tx_modulus;

    if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
        (val != ((-val) & val)) || (val >= ctx->tx_max)) {
        pr_debug("Using default transmit modulus: 4 bytes\n");
        ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
    }

    /* verify the payload remainder */
    if (ctx->tx_remainder >= ctx->tx_modulus) {
        pr_debug("Using default transmit remainder: 0 bytes\n");
        ctx->tx_remainder = 0;
    }

    /* adjust TX-remainder according to NCM specification. */
    ctx->tx_remainder = ((ctx->tx_remainder - ETH_HLEN) &
                        (ctx->tx_modulus - 1));

    /* additional configuration */

    /* set CRC Mode */
    if (flags & USB_CDC_NCM_NCAP_CRC_MODE) {
        err = usb_control_msg(ctx->udev, usb_sndctrlpipe(ctx->udev, 0),
                USB_CDC_SET_CRC_MODE,
                USB_TYPE_CLASS | USB_DIR_OUT
                 | USB_RECIP_INTERFACE,
                USB_CDC_NCM_CRC_NOT_APPENDED,
                iface_no, NULL, 0, 1000);
        if (err < 0)
            pr_debug("Setting CRC mode off failed\n");
    }

    /* set NTB format, if both formats are supported */
    if (ntb_fmt_supported & USB_CDC_NCM_NTH32_SIGN) {
        err = usb_control_msg(ctx->udev, usb_sndctrlpipe(ctx->udev, 0),
                USB_CDC_SET_NTB_FORMAT, USB_TYPE_CLASS
                 | USB_DIR_OUT | USB_RECIP_INTERFACE,
                USB_CDC_NCM_NTB16_FORMAT,
                iface_no, NULL, 0, 1000);
        if (err < 0)
            pr_debug("Setting NTB format to 16-bit failed\n");
    }

    ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;

    /* set Max Datagram Size (MTU) */
    if (flags & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE) {
        __le16 *max_datagram_size;
        u16 eth_max_sz = le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);

        max_datagram_size = kzalloc(sizeof(*max_datagram_size),
                GFP_KERNEL);
        if (!max_datagram_size) {
            err = -ENOMEM;
            goto max_dgram_err;
        }

        err = usb_control_msg(ctx->udev, usb_rcvctrlpipe(ctx->udev, 0),
                USB_CDC_GET_MAX_DATAGRAM_SIZE,
                USB_TYPE_CLASS | USB_DIR_IN
                 | USB_RECIP_INTERFACE,
                0, iface_no, max_datagram_size,
                2, 1000);
        if (err < 0) {
            pr_debug("GET_MAX_DATAGRAM_SIZE failed, use size=%u\n",
                        CDC_NCM_MIN_DATAGRAM_SIZE);
        } else {
            ctx->max_datagram_size =
                le16_to_cpu(*max_datagram_size);
            /* Check Eth descriptor value */
            if (ctx->max_datagram_size > eth_max_sz)
                    ctx->max_datagram_size = eth_max_sz;

            if (ctx->max_datagram_size > CDC_NCM_MAX_DATAGRAM_SIZE)
                ctx->max_datagram_size =
                        CDC_NCM_MAX_DATAGRAM_SIZE;

            if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)
                ctx->max_datagram_size =
                    CDC_NCM_MIN_DATAGRAM_SIZE;

            /* if value changed, update device */
            if (ctx->max_datagram_size !=
                    le16_to_cpu(*max_datagram_size)) {
                err = usb_control_msg(ctx->udev,
                        usb_sndctrlpipe(ctx->udev, 0),
                        USB_CDC_SET_MAX_DATAGRAM_SIZE,
                        USB_TYPE_CLASS | USB_DIR_OUT
                         | USB_RECIP_INTERFACE,
                        0,
                        iface_no, max_datagram_size,
                        2, 1000);
                if (err < 0)
                    pr_debug("SET_MAX_DGRAM_SIZE failed\n");
            }
        }
        kfree(max_datagram_size);
    }

max_dgram_err:
    if (ctx->netdev->mtu != (ctx->max_datagram_size - ETH_HLEN))
        ctx->netdev->mtu = ctx->max_datagram_size - ETH_HLEN;

    return 0;
}

static void
cdc_ncm_find_endpoints(struct cdc_ncm_ctx *ctx, struct usb_interface *intf)
{
    struct usb_host_endpoint *e;
    u8 ep;

    for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {

        e = intf->cur_altsetting->endpoint + ep;
        switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_INT:
            if (usb_endpoint_dir_in(&e->desc)) {
                if (ctx->status_ep == NULL)
                    ctx->status_ep = e;
            }
            break;

        case USB_ENDPOINT_XFER_BULK:
            if (usb_endpoint_dir_in(&e->desc)) {
                if (ctx->in_ep == NULL)
                    ctx->in_ep = e;
            } else {
                if (ctx->out_ep == NULL)
                    ctx->out_ep = e;
            }
            break;

        default:
            break;
        }
    }
}

static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
{
    if (ctx == NULL)
        return;

    if (ctx->tx_rem_skb != NULL) {
        dev_kfree_skb_any(ctx->tx_rem_skb);
        ctx->tx_rem_skb = NULL;
    }

    if (ctx->tx_curr_skb != NULL) {
        dev_kfree_skb_any(ctx->tx_curr_skb);
        ctx->tx_curr_skb = NULL;
    }

    kfree(ctx);
}

static const struct ethtool_ops cdc_ncm_ethtool_ops = {
    .get_drvinfo = cdc_ncm_get_drvinfo,
    .get_link = usbnet_get_link,
    .get_msglevel = usbnet_get_msglevel,
    .set_msglevel = usbnet_set_msglevel,
    .get_settings = usbnet_get_settings,
    .set_settings = usbnet_set_settings,
    .nway_reset = usbnet_nway_reset,
};

static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
{
    struct cdc_ncm_ctx *ctx;
    struct usb_driver *driver;
    u8 *buf;
    int len;
    int temp;
    u8 iface_no;

    ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
    if (ctx == NULL)
        return -ENODEV;

    hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
    ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
    ctx->bh.data = (unsigned long)ctx;
    ctx->bh.func = cdc_ncm_txpath_bh;
    atomic_set(&ctx->stop, 0);
    spin_lock_init(&ctx->mtx);
    ctx->netdev = dev->net;

    /* store ctx pointer in device data field */
    dev->data[0] = (unsigned long)ctx;

    /* get some pointers */
    driver = driver_of(intf);
    buf = intf->cur_altsetting->extra;
    len = intf->cur_altsetting->extralen;

    ctx->udev = dev->udev;
    ctx->intf = intf;

    /* parse through descriptors associated with control interface */
    while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {

        if (buf[1] != USB_DT_CS_INTERFACE)
            goto advance;

        switch (buf[2]) {
        case USB_CDC_UNION_TYPE:
            if (buf[0] < sizeof(*(ctx->union_desc)))
                break;

            ctx->union_desc =
                    (const struct usb_cdc_union_desc *)buf;

            ctx->control = usb_ifnum_to_if(dev->udev,
                    ctx->union_desc->bMasterInterface0);
            ctx->data = usb_ifnum_to_if(dev->udev,
                    ctx->union_desc->bSlaveInterface0);
            break;

        case USB_CDC_ETHERNET_TYPE:
            if (buf[0] < sizeof(*(ctx->ether_desc)))
                break;

            ctx->ether_desc =
                    (const struct usb_cdc_ether_desc *)buf;
            dev->hard_mtu =
                le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);

            if (dev->hard_mtu < CDC_NCM_MIN_DATAGRAM_SIZE)
                dev->hard_mtu = CDC_NCM_MIN_DATAGRAM_SIZE;
            else if (dev->hard_mtu > CDC_NCM_MAX_DATAGRAM_SIZE)
                dev->hard_mtu = CDC_NCM_MAX_DATAGRAM_SIZE;
            break;

        case USB_CDC_NCM_TYPE:
            if (buf[0] < sizeof(*(ctx->func_desc)))
                break;

            ctx->func_desc = (const struct usb_cdc_ncm_desc *)buf;
            break;

        default:
            break;
        }
advance:
        /* advance to next descriptor */
        temp = buf[0];
        buf += temp;
        len -= temp;
    }

    /* check if we got everything */
    if ((ctx->control == NULL) || (ctx->data == NULL) ||
        (ctx->ether_desc == NULL) || (ctx->control != intf))
        goto error;

    /* claim data interface, if different from control */
    if (ctx->data != ctx->control) {
        temp = usb_driver_claim_interface(driver, ctx->data, dev);
        if (temp)
            goto error;
    }

    iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;

    /* reset data interface */
    temp = usb_set_interface(dev->udev, iface_no, 0);
    if (temp)
        goto error2;

    /* initialize data interface */
    if (cdc_ncm_setup(ctx))
        goto error2;

    /* configure data interface */
    temp = usb_set_interface(dev->udev, iface_no, 1);
    if (temp)
        goto error2;

    cdc_ncm_find_endpoints(ctx, ctx->data);
    cdc_ncm_find_endpoints(ctx, ctx->control);

    if ((ctx->in_ep == NULL) || (ctx->out_ep == NULL) ||
        (ctx->status_ep == NULL))
        goto error2;

    dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;

    usb_set_intfdata(ctx->data, dev);
    usb_set_intfdata(ctx->control, dev);
    usb_set_intfdata(ctx->intf, dev);

    temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
    if (temp)
        goto error2;

    dev_info(&dev->udev->dev, "MAC-Address: %pM\n", dev->net->dev_addr);

    dev->in = usb_rcvbulkpipe(dev->udev,
        ctx->in_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
    dev->out = usb_sndbulkpipe(dev->udev,
        ctx->out_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
    dev->status = ctx->status_ep;
    dev->rx_urb_size = ctx->rx_max;

    /*
     * We should get an event when network connection is "connected" or
     * "disconnected". Set network connection in "disconnected" state
     * (carrier is OFF) during attach, so the IP network stack does not
     * start IPv6 negotiation and more.
     */
    netif_carrier_off(dev->net);
    ctx->tx_speed = ctx->rx_speed = 0;
    return 0;

error2:
    usb_set_intfdata(ctx->control, NULL);
    usb_set_intfdata(ctx->data, NULL);
    usb_driver_release_interface(driver, ctx->data);
error:
    cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
    dev->data[0] = 0;
    dev_info(&dev->udev->dev, "bind() failure\n");
    return -ENODEV;
}

static void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
{
    struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
    struct usb_driver *driver = driver_of(intf);

    if (ctx == NULL)
        return;     /* no setup */

    atomic_set(&ctx->stop, 1);

    if (hrtimer_active(&ctx->tx_timer))
        hrtimer_cancel(&ctx->tx_timer);

    tasklet_kill(&ctx->bh);

    /* handle devices with combined control and data interface */
    if (ctx->control == ctx->data)
        ctx->data = NULL;

    /* disconnect master --> disconnect slave */
    if (intf == ctx->control && ctx->data) {
        usb_set_intfdata(ctx->data, NULL);
        usb_driver_release_interface(driver, ctx->data);
        ctx->data = NULL;

    } else if (intf == ctx->data && ctx->control) {
        usb_set_intfdata(ctx->control, NULL);
        usb_driver_release_interface(driver, ctx->control);
        ctx->control = NULL;
    }

    usb_set_intfdata(ctx->intf, NULL);
    cdc_ncm_free(ctx);
}

static void cdc_ncm_zero_fill(u8 *ptr, u32 first, u32 end, u32 max)
{
    if (first >= max)
        return;
    if (first >= end)
        return;
    if (end > max)
        end = max;
    memset(ptr + first, 0, end - first);
}

static struct sk_buff *
cdc_ncm_fill_tx_frame(struct cdc_ncm_ctx *ctx, struct sk_buff *skb)
{
    struct sk_buff *skb_out;
    u32 rem;
    u32 offset;
    u32 last_offset;
    u16 n = 0, index;
    u8 ready2send = 0;

    /* if there is a remaining skb, it gets priority */
    if (skb != NULL)
        swap(skb, ctx->tx_rem_skb);
    else
        ready2send = 1;

    /*
     * +----------------+
     * | skb_out        |
     * +----------------+
     *           ^ offset
     *        ^ last_offset
     */

    /* check if we are resuming an OUT skb */
    if (ctx->tx_curr_skb != NULL) {
        /* pop variables */
        skb_out = ctx->tx_curr_skb;
        offset = ctx->tx_curr_offset;
        last_offset = ctx->tx_curr_last_offset;
        n = ctx->tx_curr_frame_num;

    } else {
        /* reset variables */
        skb_out = alloc_skb((ctx->tx_max + 1), GFP_ATOMIC);
        if (skb_out == NULL) {
            if (skb != NULL) {
                dev_kfree_skb_any(skb);
                ctx->netdev->stats.tx_dropped++;
            }
            goto exit_no_skb;
        }

        /* make room for NTH and NDP */
        offset = ALIGN(sizeof(struct usb_cdc_ncm_nth16),
                    ctx->tx_ndp_modulus) +
                    sizeof(struct usb_cdc_ncm_ndp16) +
                    (ctx->tx_max_datagrams + 1) *
                    sizeof(struct usb_cdc_ncm_dpe16);

        /* store last valid offset before alignment */
        last_offset = offset;
        /* align first Datagram offset correctly */
        offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
        /* zero buffer till the first IP datagram */
        cdc_ncm_zero_fill(skb_out->data, 0, offset, offset);
        n = 0;
        ctx->tx_curr_frame_num = 0;
    }

    for (; n < ctx->tx_max_datagrams; n++) {
        /* check if end of transmit buffer is reached */
        if (offset >= ctx->tx_max) {
            ready2send = 1;
            break;
        }
        /* compute maximum buffer size */
        rem = ctx->tx_max - offset;

        if (skb == NULL) {
            skb = ctx->tx_rem_skb;
            ctx->tx_rem_skb = NULL;

            /* check for end of skb */
            if (skb == NULL)
                break;
        }

        if (skb->len > rem) {
            if (n == 0) {
                /* won't fit, MTU problem? */
                dev_kfree_skb_any(skb);
                skb = NULL;
                ctx->netdev->stats.tx_dropped++;
            } else {
                /* no room for skb - store for later */
                if (ctx->tx_rem_skb != NULL) {
                    dev_kfree_skb_any(ctx->tx_rem_skb);
                    ctx->netdev->stats.tx_dropped++;
                }
                ctx->tx_rem_skb = skb;
                skb = NULL;
                ready2send = 1;
            }
            break;
        }

        memcpy(((u8 *)skb_out->data) + offset, skb->data, skb->len);

        ctx->tx_ncm.dpe16[n].wDatagramLength = cpu_to_le16(skb->len);
        ctx->tx_ncm.dpe16[n].wDatagramIndex = cpu_to_le16(offset);

        /* update offset */
        offset += skb->len;

        /* store last valid offset before alignment */
        last_offset = offset;

        /* align offset correctly */
        offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;

        /* zero padding */
        cdc_ncm_zero_fill(skb_out->data, last_offset, offset,
                                ctx->tx_max);
        dev_kfree_skb_any(skb);
        skb = NULL;
    }

    /* free up any dangling skb */
    if (skb != NULL) {
        dev_kfree_skb_any(skb);
        skb = NULL;
        ctx->netdev->stats.tx_dropped++;
    }

    ctx->tx_curr_frame_num = n;

    if (n == 0) {
        /* wait for more frames */
        /* push variables */
        ctx->tx_curr_skb = skb_out;
        ctx->tx_curr_offset = offset;
        ctx->tx_curr_last_offset = last_offset;
        goto exit_no_skb;

    } else if ((n < ctx->tx_max_datagrams) && (ready2send == 0)) {
        /* wait for more frames */
        /* push variables */
        ctx->tx_curr_skb = skb_out;
        ctx->tx_curr_offset = offset;
        ctx->tx_curr_last_offset = last_offset;
        /* set the pending count */
        if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
            ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
        goto exit_no_skb;

    } else {
        /* frame goes out */
        /* variables will be reset at next call */
    }

    /* check for overflow */
    if (last_offset > ctx->tx_max)
        last_offset = ctx->tx_max;

    /* revert offset */
    offset = last_offset;

    /*
     * If collected data size is less or equal CDC_NCM_MIN_TX_PKT bytes,
     * we send buffers as it is. If we get more data, it would be more
     * efficient for USB HS mobile device with DMA engine to receive a full
     * size NTB, than canceling DMA transfer and receiving a short packet.
     */
    if (offset > CDC_NCM_MIN_TX_PKT)
        offset = ctx->tx_max;

    /* final zero padding */
    cdc_ncm_zero_fill(skb_out->data, last_offset, offset, ctx->tx_max);

    /* store last offset */
    last_offset = offset;

    if (((last_offset < ctx->tx_max) && ((last_offset %
            le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) ||
        (((last_offset == ctx->tx_max) && ((ctx->tx_max %
        le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) &&
        (ctx->tx_max < le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize)))) {
        /* force short packet */
        *(((u8 *)skb_out->data) + last_offset) = 0;
        last_offset++;
    }

    /* zero the rest of the DPEs plus the last NULL entry */
    for (; n <= CDC_NCM_DPT_DATAGRAMS_MAX; n++) {
        ctx->tx_ncm.dpe16[n].wDatagramLength = 0;
        ctx->tx_ncm.dpe16[n].wDatagramIndex = 0;
    }

    /* fill out 16-bit NTB header */
    ctx->tx_ncm.nth16.dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
    ctx->tx_ncm.nth16.wHeaderLength =
                    cpu_to_le16(sizeof(ctx->tx_ncm.nth16));
    ctx->tx_ncm.nth16.wSequence = cpu_to_le16(ctx->tx_seq);
    ctx->tx_ncm.nth16.wBlockLength = cpu_to_le16(last_offset);
    index = ALIGN(sizeof(struct usb_cdc_ncm_nth16), ctx->tx_ndp_modulus);
    ctx->tx_ncm.nth16.wNdpIndex = cpu_to_le16(index);

    memcpy(skb_out->data, &(ctx->tx_ncm.nth16), sizeof(ctx->tx_ncm.nth16));
    ctx->tx_seq++;

    /* fill out 16-bit NDP table */
    ctx->tx_ncm.ndp16.dwSignature =
                cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN);
    rem = sizeof(ctx->tx_ncm.ndp16) + ((ctx->tx_curr_frame_num + 1) *
                    sizeof(struct usb_cdc_ncm_dpe16));
    ctx->tx_ncm.ndp16.wLength = cpu_to_le16(rem);
    ctx->tx_ncm.ndp16.wNextNdpIndex = 0; /* reserved */

    memcpy(((u8 *)skb_out->data) + index,
                        &(ctx->tx_ncm.ndp16),
                        sizeof(ctx->tx_ncm.ndp16));

    memcpy(((u8 *)skb_out->data) + index + sizeof(ctx->tx_ncm.ndp16),
                    &(ctx->tx_ncm.dpe16),
                    (ctx->tx_curr_frame_num + 1) *
                    sizeof(struct usb_cdc_ncm_dpe16));

    /* set frame length */
    skb_put(skb_out, last_offset);

    /* return skb */
    ctx->tx_curr_skb = NULL;
    ctx->netdev->stats.tx_packets += ctx->tx_curr_frame_num;
    return skb_out;

exit_no_skb:
    /* Start timer, if there is a remaining skb */
    if (ctx->tx_curr_skb != NULL)
        cdc_ncm_tx_timeout_start(ctx);
    return NULL;
}

static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
{
    /* start timer, if not already started */
    if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
        hrtimer_start(&ctx->tx_timer,
                ktime_set(0, CDC_NCM_TIMER_INTERVAL),
                HRTIMER_MODE_REL);
}

static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
{
    struct cdc_ncm_ctx *ctx =
            container_of(timer, struct cdc_ncm_ctx, tx_timer);

    if (!atomic_read(&ctx->stop))
        tasklet_schedule(&ctx->bh);
    return HRTIMER_NORESTART;
}

static void cdc_ncm_txpath_bh(unsigned long param)
{
    struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)param;

    spin_lock_bh(&ctx->mtx);
    if (ctx->tx_timer_pending != 0) {
        ctx->tx_timer_pending--;
        cdc_ncm_tx_timeout_start(ctx);
        spin_unlock_bh(&ctx->mtx);
    } else if (ctx->netdev != NULL) {
        spin_unlock_bh(&ctx->mtx);
        netif_tx_lock_bh(ctx->netdev);
        usbnet_start_xmit(NULL, ctx->netdev);
        netif_tx_unlock_bh(ctx->netdev);
    }
}

static struct sk_buff *
cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
    struct sk_buff *skb_out;
    struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];

    /*
     * The Ethernet API we are using does not support transmitting
     * multiple Ethernet frames in a single call. This driver will
     * accumulate multiple Ethernet frames and send out a larger
     * USB frame when the USB buffer is full or when a single jiffies
     * timeout happens.
     */
    if (ctx == NULL)
        goto error;

    spin_lock_bh(&ctx->mtx);
    skb_out = cdc_ncm_fill_tx_frame(ctx, skb);
    spin_unlock_bh(&ctx->mtx);
    return skb_out;

error:
    if (skb != NULL)
        dev_kfree_skb_any(skb);

    return NULL;
}

static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
{
    struct sk_buff *skb;
    struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
    int len;
    int nframes;
    int x;
    int offset;
    struct usb_cdc_ncm_nth16 *nth16;
    struct usb_cdc_ncm_ndp16 *ndp16;
    struct usb_cdc_ncm_dpe16 *dpe16;

    if (ctx == NULL)
        goto error;

    if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
                    sizeof(struct usb_cdc_ncm_ndp16))) {
        pr_debug("frame too short\n");
        goto error;
    }

    nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;

    if (le32_to_cpu(nth16->dwSignature) != USB_CDC_NCM_NTH16_SIGN) {
        pr_debug("invalid NTH16 signature <%u>\n",
                    le32_to_cpu(nth16->dwSignature));
        goto error;
    }

    len = le16_to_cpu(nth16->wBlockLength);
    if (len > ctx->rx_max) {
        pr_debug("unsupported NTB block length %u/%u\n", len,
                                ctx->rx_max);
        goto error;
    }

    if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
        (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
        !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
        pr_debug("sequence number glitch prev=%d curr=%d\n",
                ctx->rx_seq, le16_to_cpu(nth16->wSequence));
    }
    ctx->rx_seq = le16_to_cpu(nth16->wSequence);

    len = le16_to_cpu(nth16->wNdpIndex);
    if ((len + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
        pr_debug("invalid DPT16 index <%u>\n",
                    le16_to_cpu(nth16->wNdpIndex));
        goto error;
    }

    ndp16 = (struct usb_cdc_ncm_ndp16 *)(((u8 *)skb_in->data) + len);

    if (le32_to_cpu(ndp16->dwSignature) != USB_CDC_NCM_NDP16_NOCRC_SIGN) {
        pr_debug("invalid DPT16 signature <%u>\n",
                    le32_to_cpu(ndp16->dwSignature));
        goto error;
    }

    if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
        pr_debug("invalid DPT16 length <%u>\n",
                    le32_to_cpu(ndp16->dwSignature));
        goto error;
    }

    nframes = ((le16_to_cpu(ndp16->wLength) -
                    sizeof(struct usb_cdc_ncm_ndp16)) /
                    sizeof(struct usb_cdc_ncm_dpe16));
    nframes--; /* we process NDP entries except for the last one */

    len += sizeof(struct usb_cdc_ncm_ndp16);

    if ((len + nframes * (sizeof(struct usb_cdc_ncm_dpe16))) >
                                skb_in->len) {
        pr_debug("Invalid nframes = %d\n", nframes);
        goto error;
    }

    dpe16 = (struct usb_cdc_ncm_dpe16 *)(((u8 *)skb_in->data) + len);

    for (x = 0; x < nframes; x++, dpe16++) {
        offset = le16_to_cpu(dpe16->wDatagramIndex);
        len = le16_to_cpu(dpe16->wDatagramLength);

        /*
         * CDC NCM ch. 3.7
         * All entries after first NULL entry are to be ignored
         */
        if ((offset == 0) || (len == 0)) {
            if (!x)
                goto error; /* empty NTB */
            break;
        }

        /* sanity checking */
        if (((offset + len) > skb_in->len) ||
                (len > ctx->rx_max) || (len < ETH_HLEN)) {
            pr_debug("invalid frame detected (ignored)"
                    "offset[%u]=%u, length=%u, skb=%p\n",
                    x, offset, len, skb_in);
            if (!x)
                goto error;
            break;

        } else {
            skb = skb_clone(skb_in, GFP_ATOMIC);
            if (!skb)
                goto error;
            skb->len = len;
            skb->data = ((u8 *)skb_in->data) + offset;
            skb_set_tail_pointer(skb, len);
            usbnet_skb_return(dev, skb);
        }
    }
    return 1;
error:
    return 0;
}

static void
cdc_ncm_speed_change(struct cdc_ncm_ctx *ctx,
             struct usb_cdc_speed_change *data)
{
    uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
    uint32_t tx_speed = le32_to_cpu(data->ULBitRate);

    /*
     * Currently the USB-NET API does not support reporting the actual
     * device speed. Do print it instead.
     */
    if ((tx_speed != ctx->tx_speed) || (rx_speed != ctx->rx_speed)) {
        ctx->tx_speed = tx_speed;
        ctx->rx_speed = rx_speed;

        if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
            printk(KERN_INFO KBUILD_MODNAME
                ": %s: %u mbit/s downlink "
                "%u mbit/s uplink\n",
                ctx->netdev->name,
                (unsigned int)(rx_speed / 1000000U),
                (unsigned int)(tx_speed / 1000000U));
        } else {
            printk(KERN_INFO KBUILD_MODNAME
                ": %s: %u kbit/s downlink "
                "%u kbit/s uplink\n",
                ctx->netdev->name,
                (unsigned int)(rx_speed / 1000U),
                (unsigned int)(tx_speed / 1000U));
        }
    }
}

static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
{
    struct cdc_ncm_ctx *ctx;
    struct usb_cdc_notification *event;

    ctx = (struct cdc_ncm_ctx *)dev->data[0];

    if (urb->actual_length < sizeof(*event))
        return;

    /* test for split data in 8-byte chunks */
    if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
        cdc_ncm_speed_change(ctx,
              (struct usb_cdc_speed_change *)urb->transfer_buffer);
        return;
    }

    event = urb->transfer_buffer;

    switch (event->bNotificationType) {
    case USB_CDC_NOTIFY_NETWORK_CONNECTION:
        /*
         * According to the CDC NCM specification ch.7.1
         * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
         * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
         */
        ctx->connected = event->wValue;

        printk(KERN_INFO KBUILD_MODNAME ": %s: network connection:"
            " %sconnected\n",
            ctx->netdev->name, ctx->connected ? "" : "dis");

        if (ctx->connected)
            netif_carrier_on(dev->net);
        else {
            netif_carrier_off(dev->net);
            ctx->tx_speed = ctx->rx_speed = 0;
        }
        break;

    case USB_CDC_NOTIFY_SPEED_CHANGE:
        if (urb->actual_length < (sizeof(*event) +
                    sizeof(struct usb_cdc_speed_change)))
            set_bit(EVENT_STS_SPLIT, &dev->flags);
        else
            cdc_ncm_speed_change(ctx,
                (struct usb_cdc_speed_change *) &event[1]);
        break;

    default:
        dev_err(&dev->udev->dev, "NCM: unexpected "
            "notification 0x%02x!\n", event->bNotificationType);
        break;
    }
}

static int cdc_ncm_check_connect(struct usbnet *dev)
{
    struct cdc_ncm_ctx *ctx;

    ctx = (struct cdc_ncm_ctx *)dev->data[0];
    if (ctx == NULL)
        return 1;   /* disconnected */

    return !ctx->connected;
}

static int
cdc_ncm_probe(struct usb_interface *udev, const struct usb_device_id *prod)
{
    return usbnet_probe(udev, prod);
}

static void cdc_ncm_disconnect(struct usb_interface *intf)
{
    struct usbnet *dev = usb_get_intfdata(intf);

    if (dev == NULL)
        return;     /* already disconnected */

    usbnet_disconnect(intf);
}

static int cdc_ncm_manage_power(struct usbnet *dev, int status)
{
    dev->intf->needs_remote_wakeup = status;
    return 0;
}

static const struct driver_info cdc_ncm_info = {
    .description = "CDC NCM",
    .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
    .bind = cdc_ncm_bind,
    .unbind = cdc_ncm_unbind,
    .check_connect = cdc_ncm_check_connect,
    .manage_power = cdc_ncm_manage_power,
    .status = cdc_ncm_status,
    .rx_fixup = cdc_ncm_rx_fixup,
    .tx_fixup = cdc_ncm_tx_fixup,
};

/* Same as cdc_ncm_info, but with FLAG_WWAN */
static const struct driver_info wwan_info = {
    .description = "Mobile Broadband Network Device",
    .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
            | FLAG_WWAN,
    .bind = cdc_ncm_bind,
    .unbind = cdc_ncm_unbind,
    .check_connect = cdc_ncm_check_connect,
    .manage_power = cdc_ncm_manage_power,
    .status = cdc_ncm_status,
    .rx_fixup = cdc_ncm_rx_fixup,
    .tx_fixup = cdc_ncm_tx_fixup,
};

static const struct usb_device_id cdc_devs[] = {
    /* Ericsson MBM devices like F5521gw */
    { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
        | USB_DEVICE_ID_MATCH_VENDOR,
      .idVendor = 0x0bdb,
      .bInterfaceClass = USB_CLASS_COMM,
      .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
      .bInterfaceProtocol = USB_CDC_PROTO_NONE,
      .driver_info = (unsigned long) &wwan_info,
    },

    /* Dell branded MBM devices like DW5550 */
    { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
        | USB_DEVICE_ID_MATCH_VENDOR,
      .idVendor = 0x413c,
      .bInterfaceClass = USB_CLASS_COMM,
      .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
      .bInterfaceProtocol = USB_CDC_PROTO_NONE,
      .driver_info = (unsigned long) &wwan_info,
    },

    /* Toshiba branded MBM devices */
    { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
        | USB_DEVICE_ID_MATCH_VENDOR,
      .idVendor = 0x0930,
      .bInterfaceClass = USB_CLASS_COMM,
      .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
      .bInterfaceProtocol = USB_CDC_PROTO_NONE,
      .driver_info = (unsigned long) &wwan_info,
    },

    /* Huawei NCM devices disguised as vendor specific */
    { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
      .driver_info = (unsigned long)&wwan_info,
    },
    { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
      .driver_info = (unsigned long)&wwan_info,
    },

    /* Generic CDC-NCM devices */
    { USB_INTERFACE_INFO(USB_CLASS_COMM,
        USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
        .driver_info = (unsigned long)&cdc_ncm_info,
    },
    {
    },
};
MODULE_DEVICE_TABLE(usb, cdc_devs);

static struct usb_driver cdc_ncm_driver = {
    .name = "cdc_ncm",
    .id_table = cdc_devs,
    .probe = cdc_ncm_probe,
    .disconnect = cdc_ncm_disconnect,
    .suspend = usbnet_suspend,
    .resume = usbnet_resume,
    .reset_resume = usbnet_resume,
    .supports_autosuspend = 1,
    .disable_hub_initiated_lpm = 1,
};

module_usb_driver(cdc_ncm_driver);

MODULE_AUTHOR("Hans Petter Selasky");
MODULE_DESCRIPTION("USB CDC NCM host driver");
MODULE_LICENSE("Dual BSD/GPL");