[platform/kernel/u-boot.git] / drivers / usb / gadget / ether.c

/*
 * ether.c -- Ethernet gadget driver, with CDC and non-CDC options
 *
 * Copyright (C) 2003-2005,2008 David Brownell
 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
 * Copyright (C) 2008 Nokia Corporation
 *
 * 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
 */

#include <common.h>
#include <asm/errno.h>
#include <linux/netdevice.h>
#include <linux/usb/ch9.h>
#include <linux/usb/cdc.h>
#include <linux/usb/gadget.h>
#include <net.h>
#include <linux/ctype.h>

#include "gadget_chips.h"

#define USB_NET_NAME "usb_ether"

#define atomic_read
extern struct platform_data brd;
#define spin_lock(x)
#define spin_unlock(x)


unsigned packet_received, packet_sent;

#define DEV_CONFIG_CDC  1
#define GFP_ATOMIC ((gfp_t) 0)
#define GFP_KERNEL ((gfp_t) 0)

/*
 * Ethernet gadget driver -- with CDC and non-CDC options
 * Builds on hardware support for a full duplex link.
 *
 * CDC Ethernet is the standard USB solution for sending Ethernet frames
 * using USB.  Real hardware tends to use the same framing protocol but look
 * different for control features.  This driver strongly prefers to use
 * this USB-IF standard as its open-systems interoperability solution;
 * most host side USB stacks (except from Microsoft) support it.
 *
 * This is sometimes called "CDC ECM" (Ethernet Control Model) to support
 * TLA-soup.  "CDC ACM" (Abstract Control Model) is for modems, and a new
 * "CDC EEM" (Ethernet Emulation Model) is starting to spread.
 *
 * There's some hardware that can't talk CDC ECM.  We make that hardware
 * implement a "minimalist" vendor-agnostic CDC core:  same framing, but
 * link-level setup only requires activating the configuration.  Only the
 * endpoint descriptors, and product/vendor IDs, are relevant; no control
 * operations are available.  Linux supports it, but other host operating
 * systems may not.  (This is a subset of CDC Ethernet.)
 *
 * It turns out that if you add a few descriptors to that "CDC Subset",
 * (Windows) host side drivers from MCCI can treat it as one submode of
 * a proprietary scheme called "SAFE" ... without needing to know about
 * specific product/vendor IDs.  So we do that, making it easier to use
 * those MS-Windows drivers.  Those added descriptors make it resemble a
 * CDC MDLM device, but they don't change device behavior at all.  (See
 * MCCI Engineering report 950198 "SAFE Networking Functions".)
 *
 * A third option is also in use.  Rather than CDC Ethernet, or something
 * simpler, Microsoft pushes their own approach: RNDIS.  The published
 * RNDIS specs are ambiguous and appear to be incomplete, and are also
 * needlessly complex.  They borrow more from CDC ACM than CDC ECM.
 */
#define ETH_ALEN        6               /* Octets in one ethernet addr   */
#define ETH_HLEN        14              /* Total octets in header.       */
#define ETH_ZLEN        60              /* Min. octets in frame sans FCS */
#define ETH_DATA_LEN    1500            /* Max. octets in payload        */
#define ETH_FRAME_LEN   PKTSIZE_ALIGN   /* Max. octets in frame sans FCS */
#define ETH_FCS_LEN     4               /* Octets in the FCS             */

#define DRIVER_DESC             "Ethernet Gadget"
/* Based on linux 2.6.27 version */
#define DRIVER_VERSION          "May Day 2005"

static const char shortname[] = "ether";
static const char driver_desc[] = DRIVER_DESC;

#define RX_EXTRA        20              /* guard against rx overflows */

/* CDC support the same host-chosen outgoing packet filters. */
#define DEFAULT_FILTER  (USB_CDC_PACKET_TYPE_BROADCAST \
                        |USB_CDC_PACKET_TYPE_ALL_MULTICAST \
                        |USB_CDC_PACKET_TYPE_PROMISCUOUS \
                        |USB_CDC_PACKET_TYPE_DIRECTED)

#define USB_CONNECT_TIMEOUT (3 * CONFIG_SYS_HZ)

/*-------------------------------------------------------------------------*/
static struct eth_dev l_ethdev;
static struct eth_device l_netdev;
static struct usb_gadget_driver eth_driver;

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

/* "main" config is either CDC, or its simple subset */
static inline int is_cdc(struct eth_dev *dev)
{
#if     !defined(DEV_CONFIG_SUBSET)
        return 1;               /* only cdc possible */
#elif   !defined(DEV_CONFIG_CDC)
        return 0;               /* only subset possible */
#else
        return dev->cdc;        /* depends on what hardware we found */
#endif
}

#define subset_active(dev)      (!is_cdc(dev))
#define cdc_active(dev)         (is_cdc(dev))

#define DEFAULT_QLEN    2       /* double buffering by default */

/* peak bulk transfer bits-per-second */
#define HS_BPS          (13 * 512 * 8 * 1000 * 8)
#define FS_BPS          (19 *  64 * 1 * 1000 * 8)

#ifdef CONFIG_USB_GADGET_DUALSPEED
#define DEVSPEED        USB_SPEED_HIGH

#ifdef CONFIG_USB_ETH_QMULT
#define qmult CONFIG_USB_ETH_QMULT
#else
#define qmult 5
#endif

/* for dual-speed hardware, use deeper queues at highspeed */
#define qlen(gadget) \
        (DEFAULT_QLEN*((gadget->speed == USB_SPEED_HIGH) ? qmult : 1))

static inline int BITRATE(struct usb_gadget *g)
{
        return (g->speed == USB_SPEED_HIGH) ? HS_BPS : FS_BPS;
}

#else   /* full speed (low speed doesn't do bulk) */

#define qmult           1

#define DEVSPEED        USB_SPEED_FULL

#define qlen(gadget) DEFAULT_QLEN

static inline int BITRATE(struct usb_gadget *g)
{
        return FS_BPS;
}
#endif

struct eth_dev {
        struct usb_gadget       *gadget;
        struct usb_request      *req;           /* for control responses */
        struct usb_request      *stat_req;      /* for cdc status */

        u8                      config;
        struct usb_ep           *in_ep, *out_ep, *status_ep;
        const struct usb_endpoint_descriptor
                                *in, *out, *status;

        struct usb_request      *tx_req, *rx_req;

        struct eth_device       *net;
        struct net_device_stats stats;
        unsigned int            tx_qlen;

        unsigned                zlp:1;
        unsigned                cdc:1;
        unsigned                suspended:1;
        unsigned                network_started:1;
        u16                     cdc_filter;
        unsigned long           todo;
        int                     mtu;
#define WORK_RX_MEMORY          0
        u8                      host_mac[ETH_ALEN];
};

/*
 * This version autoconfigures as much as possible at run-time.
 *
 * It also ASSUMES a self-powered device, without remote wakeup,
 * although remote wakeup support would make sense.
 */

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

/*
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */

/*
 * Thanks to NetChip Technologies for donating this product ID.
 * It's for devices with only CDC Ethernet configurations.
 */
#define CDC_VENDOR_NUM          0x0525  /* NetChip */
#define CDC_PRODUCT_NUM         0xa4a1  /* Linux-USB Ethernet Gadget */

/*
 * For hardware that can't talk CDC, we use the same vendor ID that
 * ARM Linux has used for ethernet-over-usb, both with sa1100 and
 * with pxa250.  We're protocol-compatible, if the host-side drivers
 * use the endpoint descriptors.  bcdDevice (version) is nonzero, so
 * drivers that need to hard-wire endpoint numbers have a hook.
 *
 * The protocol is a minimal subset of CDC Ether, which works on any bulk
 * hardware that's not deeply broken ... even on hardware that can't talk
 * RNDIS (like SA-1100, with no interrupt endpoint, or anything that
 * doesn't handle control-OUT).
 */
#define SIMPLE_VENDOR_NUM       0x049f
#define SIMPLE_PRODUCT_NUM      0x505a

/*
 * Some systems will want different product identifers published in the
 * device descriptor, either numbers or strings or both.  These string
 * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
 */

static ushort bcdDevice;
#if defined(CONFIG_USBNET_MANUFACTURER)
static char *iManufacturer = CONFIG_USBNET_MANUFACTURER;
#else
static char *iManufacturer = "U-boot";
#endif
static char *iProduct;
static char *iSerialNumber;
static char dev_addr[18];
static char host_addr[18];

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

/*
 * USB DRIVER HOOKUP (to the hardware driver, below us), mostly
 * ep0 implementation:  descriptors, config management, setup().
 * also optional class-specific notification interrupt transfer.
 */

/*
 * DESCRIPTORS ... most are static, but strings and (full) configuration
 * descriptors are built on demand.  For now we do either full CDC, or
 * our simple subset.
 */

#define STRING_MANUFACTURER             1
#define STRING_PRODUCT                  2
#define STRING_ETHADDR                  3
#define STRING_DATA                     4
#define STRING_CONTROL                  5
#define STRING_CDC                      7
#define STRING_SUBSET                   8
#define STRING_SERIALNUMBER             10

/* holds our biggest descriptor */
#define USB_BUFSIZ      256

/*
 * This device advertises one configuration, eth_config,
 * on hardware supporting at least two configs.
 *
 * FIXME define some higher-powered configurations to make it easier
 * to recharge batteries ...
 */

#define DEV_CONFIG_VALUE        1       /* cdc or subset */

static struct usb_device_descriptor
device_desc = {
        .bLength =              sizeof device_desc,
        .bDescriptorType =      USB_DT_DEVICE,

        .bcdUSB =               __constant_cpu_to_le16(0x0200),

        .bDeviceClass =         USB_CLASS_COMM,
        .bDeviceSubClass =      0,
        .bDeviceProtocol =      0,

        .idVendor =             __constant_cpu_to_le16(CDC_VENDOR_NUM),
        .idProduct =            __constant_cpu_to_le16(CDC_PRODUCT_NUM),
        .iManufacturer =        STRING_MANUFACTURER,
        .iProduct =             STRING_PRODUCT,
        .bNumConfigurations =   1,
};

static struct usb_otg_descriptor
otg_descriptor = {
        .bLength =              sizeof otg_descriptor,
        .bDescriptorType =      USB_DT_OTG,

        .bmAttributes =         USB_OTG_SRP,
};

static struct usb_config_descriptor
eth_config = {
        .bLength =              sizeof eth_config,
        .bDescriptorType =      USB_DT_CONFIG,

        /* compute wTotalLength on the fly */
        .bNumInterfaces =       2,
        .bConfigurationValue =  DEV_CONFIG_VALUE,
        .iConfiguration =       STRING_CDC,
        .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
        .bMaxPower =            1,
};

/*
 * Compared to the simple CDC subset, the full CDC Ethernet model adds
 * three class descriptors, two interface descriptors, optional status
 * endpoint.  Both have a "data" interface and two bulk endpoints.
 * There are also differences in how control requests are handled.
 */

#ifdef  DEV_CONFIG_CDC
static struct usb_interface_descriptor
control_intf = {
        .bLength =              sizeof control_intf,
        .bDescriptorType =      USB_DT_INTERFACE,

        .bInterfaceNumber =     0,
        /* status endpoint is optional; this may be patched later */
        .bNumEndpoints =        1,
        .bInterfaceClass =      USB_CLASS_COMM,
        .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
        .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
        .iInterface =           STRING_CONTROL,
};
#endif

static const struct usb_cdc_header_desc header_desc = {
        .bLength =              sizeof header_desc,
        .bDescriptorType =      USB_DT_CS_INTERFACE,
        .bDescriptorSubType =   USB_CDC_HEADER_TYPE,

        .bcdCDC =               __constant_cpu_to_le16(0x0110),
};

#if defined(DEV_CONFIG_CDC)

static const struct usb_cdc_union_desc union_desc = {
        .bLength =              sizeof union_desc,
        .bDescriptorType =      USB_DT_CS_INTERFACE,
        .bDescriptorSubType =   USB_CDC_UNION_TYPE,

        .bMasterInterface0 =    0,      /* index of control interface */
        .bSlaveInterface0 =     1,      /* index of DATA interface */
};

#endif  /* CDC */

#ifndef DEV_CONFIG_CDC

/*
 * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various
 * ways:  data endpoints live in the control interface, there's no data
 * interface, and it's not used to talk to a cell phone radio.
 */

static const struct usb_cdc_mdlm_desc mdlm_desc = {
        .bLength =              sizeof mdlm_desc,
        .bDescriptorType =      USB_DT_CS_INTERFACE,
        .bDescriptorSubType =   USB_CDC_MDLM_TYPE,

        .bcdVersion =           __constant_cpu_to_le16(0x0100),
        .bGUID = {
                0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
                0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
        },
};

/*
 * since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
 * can't really use its struct.  All we do here is say that we're using
 * the submode of "SAFE" which directly matches the CDC Subset.
 */
static const u8 mdlm_detail_desc[] = {
        6,
        USB_DT_CS_INTERFACE,
        USB_CDC_MDLM_DETAIL_TYPE,

        0,      /* "SAFE" */
        0,      /* network control capabilities (none) */
        0,      /* network data capabilities ("raw" encapsulation) */
};

#endif

static const struct usb_cdc_ether_desc ether_desc = {
        .bLength =              sizeof(ether_desc),
        .bDescriptorType =      USB_DT_CS_INTERFACE,
        .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,

        /* this descriptor actually adds value, surprise! */
        .iMACAddress =          STRING_ETHADDR,
        .bmEthernetStatistics = __constant_cpu_to_le32(0), /* no statistics */
        .wMaxSegmentSize =      __constant_cpu_to_le16(ETH_FRAME_LEN),
        .wNumberMCFilters =     __constant_cpu_to_le16(0),
        .bNumberPowerFilters =  0,
};

#if defined(DEV_CONFIG_CDC)

/*
 * include the status endpoint if we can, even where it's optional.
 * use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
 * packet, to simplify cancellation; and a big transfer interval, to
 * waste less bandwidth.
 *
 * some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
 * if they ignore the connect/disconnect notifications that real aether
 * can provide.  more advanced cdc configurations might want to support
 * encapsulated commands (vendor-specific, using control-OUT).
 */

#define LOG2_STATUS_INTERVAL_MSEC       5       /* 1 << 5 == 32 msec */
#define STATUS_BYTECOUNT                16      /* 8 byte header + data */

static struct usb_endpoint_descriptor
fs_status_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,

        .bEndpointAddress =     USB_DIR_IN,
        .bmAttributes =         USB_ENDPOINT_XFER_INT,
        .wMaxPacketSize =       __constant_cpu_to_le16(STATUS_BYTECOUNT),
        .bInterval =            1 << LOG2_STATUS_INTERVAL_MSEC,
};
#endif

#ifdef  DEV_CONFIG_CDC

/* the default data interface has no endpoints ... */

static const struct usb_interface_descriptor
data_nop_intf = {
        .bLength =              sizeof data_nop_intf,
        .bDescriptorType =      USB_DT_INTERFACE,

        .bInterfaceNumber =     1,
        .bAlternateSetting =    0,
        .bNumEndpoints =        0,
        .bInterfaceClass =      USB_CLASS_CDC_DATA,
        .bInterfaceSubClass =   0,
        .bInterfaceProtocol =   0,
};

/* ... but the "real" data interface has two bulk endpoints */

static const struct usb_interface_descriptor
data_intf = {
        .bLength =              sizeof data_intf,
        .bDescriptorType =      USB_DT_INTERFACE,

        .bInterfaceNumber =     1,
        .bAlternateSetting =    1,
        .bNumEndpoints =        2,
        .bInterfaceClass =      USB_CLASS_CDC_DATA,
        .bInterfaceSubClass =   0,
        .bInterfaceProtocol =   0,
        .iInterface =           STRING_DATA,
};

#endif

#ifdef DEV_CONFIG_SUBSET

/*
 * "Simple" CDC-subset option is a simple vendor-neutral model that most
 * full speed controllers can handle:  one interface, two bulk endpoints.
 *
 * To assist host side drivers, we fancy it up a bit, and add descriptors
 * so some host side drivers will understand it as a "SAFE" variant.
 */

static const struct usb_interface_descriptor
subset_data_intf = {
        .bLength =              sizeof subset_data_intf,
        .bDescriptorType =      USB_DT_INTERFACE,

        .bInterfaceNumber =     0,
        .bAlternateSetting =    0,
        .bNumEndpoints =        2,
        .bInterfaceClass =      USB_CLASS_COMM,
        .bInterfaceSubClass =   USB_CDC_SUBCLASS_MDLM,
        .bInterfaceProtocol =   0,
        .iInterface =           STRING_DATA,
};

#endif  /* SUBSET */

static struct usb_endpoint_descriptor
fs_source_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,

        .bEndpointAddress =     USB_DIR_IN,
        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor
fs_sink_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,

        .bEndpointAddress =     USB_DIR_OUT,
        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
};

static const struct usb_descriptor_header *fs_eth_function[11] = {
        (struct usb_descriptor_header *) &otg_descriptor,
#ifdef DEV_CONFIG_CDC
        /* "cdc" mode descriptors */
        (struct usb_descriptor_header *) &control_intf,
        (struct usb_descriptor_header *) &header_desc,
        (struct usb_descriptor_header *) &union_desc,
        (struct usb_descriptor_header *) &ether_desc,
        /* NOTE: status endpoint may need to be removed */
        (struct usb_descriptor_header *) &fs_status_desc,
        /* data interface, with altsetting */
        (struct usb_descriptor_header *) &data_nop_intf,
        (struct usb_descriptor_header *) &data_intf,
        (struct usb_descriptor_header *) &fs_source_desc,
        (struct usb_descriptor_header *) &fs_sink_desc,
        NULL,
#endif /* DEV_CONFIG_CDC */
};

static inline void fs_subset_descriptors(void)
{
#ifdef DEV_CONFIG_SUBSET
        /* behavior is "CDC Subset"; extra descriptors say "SAFE" */
        fs_eth_function[1] = (struct usb_descriptor_header *) &subset_data_intf;
        fs_eth_function[2] = (struct usb_descriptor_header *) &header_desc;
        fs_eth_function[3] = (struct usb_descriptor_header *) &mdlm_desc;
        fs_eth_function[4] = (struct usb_descriptor_header *) &mdlm_detail_desc;
        fs_eth_function[5] = (struct usb_descriptor_header *) &ether_desc;
        fs_eth_function[6] = (struct usb_descriptor_header *) &fs_source_desc;
        fs_eth_function[7] = (struct usb_descriptor_header *) &fs_sink_desc;
        fs_eth_function[8] = NULL;
#else
        fs_eth_function[1] = NULL;
#endif
}

/*
 * usb 2.0 devices need to expose both high speed and full speed
 * descriptors, unless they only run at full speed.
 */

#if defined(DEV_CONFIG_CDC)
static struct usb_endpoint_descriptor
hs_status_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,

        .bmAttributes =         USB_ENDPOINT_XFER_INT,
        .wMaxPacketSize =       __constant_cpu_to_le16(STATUS_BYTECOUNT),
        .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
};
#endif /* DEV_CONFIG_CDC */

static struct usb_endpoint_descriptor
hs_source_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,

        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
        .wMaxPacketSize =       __constant_cpu_to_le16(512),
};

static struct usb_endpoint_descriptor
hs_sink_desc = {
        .bLength =              USB_DT_ENDPOINT_SIZE,
        .bDescriptorType =      USB_DT_ENDPOINT,

        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
        .wMaxPacketSize =       __constant_cpu_to_le16(512),
};

static struct usb_qualifier_descriptor
dev_qualifier = {
        .bLength =              sizeof dev_qualifier,
        .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,

        .bcdUSB =               __constant_cpu_to_le16(0x0200),
        .bDeviceClass =         USB_CLASS_COMM,

        .bNumConfigurations =   1,
};

static const struct usb_descriptor_header *hs_eth_function[11] = {
        (struct usb_descriptor_header *) &otg_descriptor,
#ifdef DEV_CONFIG_CDC
        /* "cdc" mode descriptors */
        (struct usb_descriptor_header *) &control_intf,
        (struct usb_descriptor_header *) &header_desc,
        (struct usb_descriptor_header *) &union_desc,
        (struct usb_descriptor_header *) &ether_desc,
        /* NOTE: status endpoint may need to be removed */
        (struct usb_descriptor_header *) &hs_status_desc,
        /* data interface, with altsetting */
        (struct usb_descriptor_header *) &data_nop_intf,
        (struct usb_descriptor_header *) &data_intf,
        (struct usb_descriptor_header *) &hs_source_desc,
        (struct usb_descriptor_header *) &hs_sink_desc,
        NULL,
#endif /* DEV_CONFIG_CDC */
};

static inline void hs_subset_descriptors(void)
{
#ifdef DEV_CONFIG_SUBSET
        /* behavior is "CDC Subset"; extra descriptors say "SAFE" */
        hs_eth_function[1] = (struct usb_descriptor_header *) &subset_data_intf;
        hs_eth_function[2] = (struct usb_descriptor_header *) &header_desc;
        hs_eth_function[3] = (struct usb_descriptor_header *) &mdlm_desc;
        hs_eth_function[4] = (struct usb_descriptor_header *) &mdlm_detail_desc;
        hs_eth_function[5] = (struct usb_descriptor_header *) &ether_desc;
        hs_eth_function[6] = (struct usb_descriptor_header *) &hs_source_desc;
        hs_eth_function[7] = (struct usb_descriptor_header *) &hs_sink_desc;
        hs_eth_function[8] = NULL;
#else
        hs_eth_function[1] = NULL;
#endif
}

/* maxpacket and other transfer characteristics vary by speed. */
static inline struct usb_endpoint_descriptor *
ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *hs,
                struct usb_endpoint_descriptor *fs)
{
        if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
                return hs;
        return fs;
}

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

/* descriptors that are built on-demand */

static char manufacturer[50];
static char product_desc[40] = DRIVER_DESC;
static char serial_number[20];

/* address that the host will use ... usually assigned at random */
static char ethaddr[2 * ETH_ALEN + 1];

/* static strings, in UTF-8 */
static struct usb_string                strings[] = {
        { STRING_MANUFACTURER,  manufacturer, },
        { STRING_PRODUCT,       product_desc, },
        { STRING_SERIALNUMBER,  serial_number, },
        { STRING_DATA,          "Ethernet Data", },
        { STRING_ETHADDR,       ethaddr, },
#ifdef  DEV_CONFIG_CDC
        { STRING_CDC,           "CDC Ethernet", },
        { STRING_CONTROL,       "CDC Communications Control", },
#endif
#ifdef  DEV_CONFIG_SUBSET
        { STRING_SUBSET,        "CDC Ethernet Subset", },
#endif
        {  }            /* end of list */
};

static struct usb_gadget_strings        stringtab = {
        .language       = 0x0409,       /* en-us */
        .strings        = strings,
};

/*============================================================================*/
static u8 control_req[USB_BUFSIZ];
static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4)));


/**
 * strlcpy - Copy a %NUL terminated string into a sized buffer
 * @dest: Where to copy the string to
 * @src: Where to copy the string from
 * @size: size of destination buffer
 *
 * Compatible with *BSD: the result is always a valid
 * NUL-terminated string that fits in the buffer (unless,
 * of course, the buffer size is zero). It does not pad
 * out the result like strncpy() does.
 */
size_t strlcpy(char *dest, const char *src, size_t size)
{
        size_t ret = strlen(src);

        if (size) {
                size_t len = (ret >= size) ? size - 1 : ret;
                memcpy(dest, src, len);
                dest[len] = '\0';
        }
        return ret;
}

/*============================================================================*/

/*
 * one config, two interfaces:  control, data.
 * complications: class descriptors, and an altsetting.
 */
static int
config_buf(struct usb_gadget *g, u8 *buf, u8 type, unsigned index, int is_otg)
{
        int                                     len;
        const struct usb_config_descriptor      *config;
        const struct usb_descriptor_header      **function;
        int                                     hs = 0;

        if (gadget_is_dualspeed(g)) {
                hs = (g->speed == USB_SPEED_HIGH);
                if (type == USB_DT_OTHER_SPEED_CONFIG)
                        hs = !hs;
        }
#define which_fn(t)     (hs ? hs_ ## t ## _function : fs_ ## t ## _function)

        if (index >= device_desc.bNumConfigurations)
                return -EINVAL;

        config = &eth_config;
        function = which_fn(eth);

        /* for now, don't advertise srp-only devices */
        if (!is_otg)
                function++;

        len = usb_gadget_config_buf(config, buf, USB_BUFSIZ, function);
        if (len < 0)
                return len;
        ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
        return len;
}

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

static int alloc_requests(struct eth_dev *dev, unsigned n, gfp_t gfp_flags);

static int
set_ether_config(struct eth_dev *dev, gfp_t gfp_flags)
{
        int                                     result = 0;
        struct usb_gadget                       *gadget = dev->gadget;

#if defined(DEV_CONFIG_CDC)
        /* status endpoint used for (optionally) CDC */
        if (!subset_active(dev) && dev->status_ep) {
                dev->status = ep_desc(gadget, &hs_status_desc,
                                                &fs_status_desc);
                dev->status_ep->driver_data = dev;

                result = usb_ep_enable(dev->status_ep, dev->status);
                if (result != 0) {
                        debug("enable %s --> %d\n",
                                dev->status_ep->name, result);
                        goto done;
                }
        }
#endif

        dev->in = ep_desc(gadget, &hs_source_desc, &fs_source_desc);
        dev->in_ep->driver_data = dev;

        dev->out = ep_desc(gadget, &hs_sink_desc, &fs_sink_desc);
        dev->out_ep->driver_data = dev;

        /*
         * With CDC,  the host isn't allowed to use these two data
         * endpoints in the default altsetting for the interface.
         * so we don't activate them yet.  Reset from SET_INTERFACE.
         */
        if (!cdc_active(dev)) {
                result = usb_ep_enable(dev->in_ep, dev->in);
                if (result != 0) {
                        debug("enable %s --> %d\n",
                                dev->in_ep->name, result);
                        goto done;
                }

                result = usb_ep_enable(dev->out_ep, dev->out);
                if (result != 0) {
                        debug("enable %s --> %d\n",
                                dev->out_ep->name, result);
                        goto done;
                }
        }

done:
        if (result == 0)
                result = alloc_requests(dev, qlen(gadget), gfp_flags);

        /* on error, disable any endpoints  */
        if (result < 0) {
                if (!subset_active(dev) && dev->status_ep)
                        (void) usb_ep_disable(dev->status_ep);
                dev->status = NULL;
                (void) usb_ep_disable(dev->in_ep);
                (void) usb_ep_disable(dev->out_ep);
                dev->in = NULL;
                dev->out = NULL;
        }

        /* caller is responsible for cleanup on error */
        return result;
}

static void eth_reset_config(struct eth_dev *dev)
{
        if (dev->config == 0)
                return;

        debug("%s\n", __func__);

        /*
         * disable endpoints, forcing (synchronous) completion of
         * pending i/o.  then free the requests.
         */

        if (dev->in) {
                usb_ep_disable(dev->in_ep);
                if (dev->tx_req) {
                        usb_ep_free_request(dev->in_ep, dev->tx_req);
                        dev->tx_req = NULL;
                }
        }
        if (dev->out) {
                usb_ep_disable(dev->out_ep);
                if (dev->rx_req) {
                        usb_ep_free_request(dev->out_ep, dev->rx_req);
                        dev->rx_req = NULL;
                }
        }
        if (dev->status)
                usb_ep_disable(dev->status_ep);

        dev->cdc_filter = 0;
        dev->config = 0;
}

/*
 * change our operational config.  must agree with the code
 * that returns config descriptors, and altsetting code.
 */
static int eth_set_config(struct eth_dev *dev, unsigned number,
                                gfp_t gfp_flags)
{
        int                     result = 0;
        struct usb_gadget       *gadget = dev->gadget;

        if (gadget_is_sa1100(gadget)
                        && dev->config
                        && dev->tx_qlen != 0) {
                /* tx fifo is full, but we can't clear it...*/
                error("can't change configurations");
                return -ESPIPE;
        }
        eth_reset_config(dev);

        switch (number) {
        case DEV_CONFIG_VALUE:
                result = set_ether_config(dev, gfp_flags);
                break;
        default:
                result = -EINVAL;
                /* FALL THROUGH */
        case 0:
                break;
        }

        if (result) {
                if (number)
                        eth_reset_config(dev);
                usb_gadget_vbus_draw(dev->gadget,
                                gadget_is_otg(dev->gadget) ? 8 : 100);
        } else {
                char *speed;
                unsigned power;

                power = 2 * eth_config.bMaxPower;
                usb_gadget_vbus_draw(dev->gadget, power);

                switch (gadget->speed) {
                case USB_SPEED_FULL:
                        speed = "full"; break;
#ifdef CONFIG_USB_GADGET_DUALSPEED
                case USB_SPEED_HIGH:
                        speed = "high"; break;
#endif
                default:
                        speed = "?"; break;
                }

                dev->config = number;
                printf("%s speed config #%d: %d mA, %s, using %s\n",
                                speed, number, power, driver_desc,
                                (cdc_active(dev) ? "CDC Ethernet"
                                                : "CDC Ethernet Subset"));
        }
        return result;
}

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

#ifdef  DEV_CONFIG_CDC

/*
 * The interrupt endpoint is used in CDC networking models (Ethernet, ATM)
 * only to notify the host about link status changes (which we support) or
 * report completion of some encapsulated command.  Since
 * we want this CDC Ethernet code to be vendor-neutral, we don't use that
 * command mechanism; and only one status request is ever queued.
 */
static void eth_status_complete(struct usb_ep *ep, struct usb_request *req)
{
        struct usb_cdc_notification     *event = req->buf;
        int                             value = req->status;
        struct eth_dev                  *dev = ep->driver_data;

        /* issue the second notification if host reads the first */
        if (event->bNotificationType == USB_CDC_NOTIFY_NETWORK_CONNECTION
                        && value == 0) {
                __le32  *data = req->buf + sizeof *event;

                event->bmRequestType = 0xA1;
                event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
                event->wValue = __constant_cpu_to_le16(0);
                event->wIndex = __constant_cpu_to_le16(1);
                event->wLength = __constant_cpu_to_le16(8);

                /* SPEED_CHANGE data is up/down speeds in bits/sec */
                data[0] = data[1] = cpu_to_le32(BITRATE(dev->gadget));

                req->length = STATUS_BYTECOUNT;
                value = usb_ep_queue(ep, req, GFP_ATOMIC);
                debug("send SPEED_CHANGE --> %d\n", value);
                if (value == 0)
                        return;
        } else if (value != -ECONNRESET) {
                debug("event %02x --> %d\n",
                        event->bNotificationType, value);
                if (event->bNotificationType ==
                                USB_CDC_NOTIFY_SPEED_CHANGE) {
                        l_ethdev.network_started = 1;
                        printf("USB network up!\n");
                }
        }
        req->context = NULL;
}

static void issue_start_status(struct eth_dev *dev)
{
        struct usb_request              *req = dev->stat_req;
        struct usb_cdc_notification     *event;
        int                             value;

        /*
         * flush old status
         *
         * FIXME ugly idiom, maybe we'd be better with just
         * a "cancel the whole queue" primitive since any
         * unlink-one primitive has way too many error modes.
         * here, we "know" toggle is already clear...
         *
         * FIXME iff req->context != null just dequeue it
         */
        usb_ep_disable(dev->status_ep);
        usb_ep_enable(dev->status_ep, dev->status);

        /*
         * 3.8.1 says to issue first NETWORK_CONNECTION, then
         * a SPEED_CHANGE.  could be useful in some configs.
         */
        event = req->buf;
        event->bmRequestType = 0xA1;
        event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
        event->wValue = __constant_cpu_to_le16(1);      /* connected */
        event->wIndex = __constant_cpu_to_le16(1);
        event->wLength = 0;

        req->length = sizeof *event;
        req->complete = eth_status_complete;
        req->context = dev;

        value = usb_ep_queue(dev->status_ep, req, GFP_ATOMIC);
        if (value < 0)
                debug("status buf queue --> %d\n", value);
}

#endif

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

static void eth_setup_complete(struct usb_ep *ep, struct usb_request *req)
{
        if (req->status || req->actual != req->length)
                debug("setup complete --> %d, %d/%d\n",
                                req->status, req->actual, req->length);
}

/*
 * The setup() callback implements all the ep0 functionality that's not
 * handled lower down.  CDC has a number of less-common features:
 *
 *  - two interfaces:  control, and ethernet data
 *  - Ethernet data interface has two altsettings:  default, and active
 *  - class-specific descriptors for the control interface
 *  - class-specific control requests
 */
static int
eth_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
{
        struct eth_dev          *dev = get_gadget_data(gadget);
        struct usb_request      *req = dev->req;
        int                     value = -EOPNOTSUPP;
        u16                     wIndex = le16_to_cpu(ctrl->wIndex);
        u16                     wValue = le16_to_cpu(ctrl->wValue);
        u16                     wLength = le16_to_cpu(ctrl->wLength);

        /*
         * descriptors just go into the pre-allocated ep0 buffer,
         * while config change events may enable network traffic.
         */

        debug("%s\n", __func__);

        req->complete = eth_setup_complete;
        switch (ctrl->bRequest) {

        case USB_REQ_GET_DESCRIPTOR:
                if (ctrl->bRequestType != USB_DIR_IN)
                        break;
                switch (wValue >> 8) {

                case USB_DT_DEVICE:
                        value = min(wLength, (u16) sizeof device_desc);
                        memcpy(req->buf, &device_desc, value);
                        break;
                case USB_DT_DEVICE_QUALIFIER:
                        if (!gadget_is_dualspeed(gadget))
                                break;
                        value = min(wLength, (u16) sizeof dev_qualifier);
                        memcpy(req->buf, &dev_qualifier, value);
                        break;

                case USB_DT_OTHER_SPEED_CONFIG:
                        if (!gadget_is_dualspeed(gadget))
                                break;
                        /* FALLTHROUGH */
                case USB_DT_CONFIG:
                        value = config_buf(gadget, req->buf,
                                        wValue >> 8,
                                        wValue & 0xff,
                                        gadget_is_otg(gadget));
                        if (value >= 0)
                                value = min(wLength, (u16) value);
                        break;

                case USB_DT_STRING:
                        value = usb_gadget_get_string(&stringtab,
                                        wValue & 0xff, req->buf);

                        if (value >= 0)
                                value = min(wLength, (u16) value);

                        break;
                }
                break;

        case USB_REQ_SET_CONFIGURATION:
                if (ctrl->bRequestType != 0)
                        break;
                if (gadget->a_hnp_support)
                        debug("HNP available\n");
                else if (gadget->a_alt_hnp_support)
                        debug("HNP needs a different root port\n");
                value = eth_set_config(dev, wValue, GFP_ATOMIC);
                break;
        case USB_REQ_GET_CONFIGURATION:
                if (ctrl->bRequestType != USB_DIR_IN)
                        break;
                *(u8 *)req->buf = dev->config;
                value = min(wLength, (u16) 1);
                break;

        case USB_REQ_SET_INTERFACE:
                if (ctrl->bRequestType != USB_RECIP_INTERFACE
                                || !dev->config
                                || wIndex > 1)
                        break;
                if (!cdc_active(dev) && wIndex != 0)
                        break;

                /*
                 * PXA hardware partially handles SET_INTERFACE;
                 * we need to kluge around that interference.
                 */
                if (gadget_is_pxa(gadget)) {
                        value = eth_set_config(dev, DEV_CONFIG_VALUE,
                                                GFP_ATOMIC);
                        goto done_set_intf;
                }

#ifdef DEV_CONFIG_CDC
                switch (wIndex) {
                case 0:         /* control/master intf */
                        if (wValue != 0)
                                break;
                        if (dev->status) {
                                usb_ep_disable(dev->status_ep);
                                usb_ep_enable(dev->status_ep, dev->status);
                        }
                        value = 0;
                        break;
                case 1:         /* data intf */
                        if (wValue > 1)
                                break;
                        usb_ep_disable(dev->in_ep);
                        usb_ep_disable(dev->out_ep);

                        /*
                         * CDC requires the data transfers not be done from
                         * the default interface setting ... also, setting
                         * the non-default interface resets filters etc.
                         */
                        if (wValue == 1) {
                                if (!cdc_active(dev))
                                        break;
                                usb_ep_enable(dev->in_ep, dev->in);
                                usb_ep_enable(dev->out_ep, dev->out);
                                dev->cdc_filter = DEFAULT_FILTER;
                                if (dev->status)
                                        issue_start_status(dev);
                        }

                        value = 0;
                        break;
                }
#else
                /*
                 * FIXME this is wrong, as is the assumption that
                 * all non-PXA hardware talks real CDC ...
                 */
                debug("set_interface ignored!\n");
#endif /* DEV_CONFIG_CDC */

done_set_intf:
                break;
        case USB_REQ_GET_INTERFACE:
                if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE)
                                || !dev->config
                                || wIndex > 1)
                        break;
                if (!(cdc_active(dev)) && wIndex != 0)
                        break;

                /* for CDC, iff carrier is on, data interface is active. */
                if (wIndex != 1)
                        *(u8 *)req->buf = 0;
                else {
                        /* *(u8 *)req->buf = netif_carrier_ok (dev->net) ? 1 : 0; */
                        /* carrier always ok ...*/
                        *(u8 *)req->buf = 1 ;
                }
                value = min(wLength, (u16) 1);
                break;

#ifdef DEV_CONFIG_CDC
        case USB_CDC_SET_ETHERNET_PACKET_FILTER:
                /*
                 * see 6.2.30: no data, wIndex = interface,
                 * wValue = packet filter bitmap
                 */
                if (ctrl->bRequestType != (USB_TYPE_CLASS|USB_RECIP_INTERFACE)
                                || !cdc_active(dev)
                                || wLength != 0
                                || wIndex > 1)
                        break;
                debug("packet filter %02x\n", wValue);
                dev->cdc_filter = wValue;
                value = 0;
                break;

        /*
         * and potentially:
         * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
         * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
         * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
         * case USB_CDC_GET_ETHERNET_STATISTIC:
         */

#endif /* DEV_CONFIG_CDC */

        default:
                debug("unknown control req%02x.%02x v%04x i%04x l%d\n",
                        ctrl->bRequestType, ctrl->bRequest,
                        wValue, wIndex, wLength);
        }

        /* respond with data transfer before status phase? */
        if (value >= 0) {
                debug("respond with data transfer before status phase\n");
                req->length = value;
                req->zero = value < wLength
                                && (value % gadget->ep0->maxpacket) == 0;
                value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
                if (value < 0) {
                        debug("ep_queue --> %d\n", value);
                        req->status = 0;
                        eth_setup_complete(gadget->ep0, req);
                }
        }

        /* host either stalls (value < 0) or reports success */
        return value;
}

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

static void rx_complete(struct usb_ep *ep, struct usb_request *req);

static int rx_submit(struct eth_dev *dev, struct usb_request *req,
                                gfp_t gfp_flags)
{
        int                     retval = -ENOMEM;
        size_t                  size;

        /*
         * Padding up to RX_EXTRA handles minor disagreements with host.
         * Normally we use the USB "terminate on short read" convention;
         * so allow up to (N*maxpacket), since that memory is normally
         * already allocated.  Some hardware doesn't deal well with short
         * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
         * byte off the end (to force hardware errors on overflow).
         */

        debug("%s\n", __func__);

        size = (ETHER_HDR_SIZE + dev->mtu + RX_EXTRA);
        size += dev->out_ep->maxpacket - 1;
        size -= size % dev->out_ep->maxpacket;

        /*
         * Some platforms perform better when IP packets are aligned,
         * but on at least one, checksumming fails otherwise.
         */

        req->buf = (u8 *) NetRxPackets[0];
        req->length = size;
        req->complete = rx_complete;

        retval = usb_ep_queue(dev->out_ep, req, gfp_flags);

        if (retval)
                error("rx submit --> %d", retval);

        return retval;
}

static void rx_complete(struct usb_ep *ep, struct usb_request *req)
{
        struct eth_dev  *dev = ep->driver_data;

        debug("%s: status %d\n", __func__, req->status);
        switch (req->status) {
        /* normal completion */
        case 0:
                dev->stats.rx_packets++;
                dev->stats.rx_bytes += req->length;
                break;

        /* software-driven interface shutdown */
        case -ECONNRESET:               /* unlink */
        case -ESHUTDOWN:                /* disconnect etc */
        /* for hardware automagic (such as pxa) */
        case -ECONNABORTED:             /* endpoint reset */
                break;

        /* data overrun */
        case -EOVERFLOW:
                dev->stats.rx_over_errors++;
                /* FALLTHROUGH */
        default:
                dev->stats.rx_errors++;
                break;
        }

        packet_received = 1;
}

static int alloc_requests(struct eth_dev *dev, unsigned n, gfp_t gfp_flags)
{

        dev->tx_req = usb_ep_alloc_request(dev->in_ep, 0);

        if (!dev->tx_req)
                goto fail1;

        dev->rx_req = usb_ep_alloc_request(dev->out_ep, 0);

        if (!dev->rx_req)
                goto fail2;

        return 0;

fail2:
        usb_ep_free_request(dev->in_ep, dev->tx_req);
fail1:
        error("can't alloc requests");
        return -1;
}

static void tx_complete(struct usb_ep *ep, struct usb_request *req)
{
        struct eth_dev  *dev = ep->driver_data;

        debug("%s: status %s\n", __func__, (req->status) ? "failed" : "ok");
        switch (req->status) {
        default:
                dev->stats.tx_errors++;
                debug("tx err %d\n", req->status);
                /* FALLTHROUGH */
        case -ECONNRESET:               /* unlink */
        case -ESHUTDOWN:                /* disconnect etc */
                break;
        case 0:
                dev->stats.tx_bytes += req->length;
        }
        dev->stats.tx_packets++;

        packet_sent = 1;
}

static inline int eth_is_promisc(struct eth_dev *dev)
{
        /* no filters for the CDC subset; always promisc */
        if (subset_active(dev))
                return 1;
        return dev->cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
}

#if 0
static int eth_start_xmit (struct sk_buff *skb, struct net_device *net)
{
        struct eth_dev          *dev = netdev_priv(net);
        int                     length = skb->len;
        int                     retval;
        struct usb_request      *req = NULL;
        unsigned long           flags;

        /* apply outgoing CDC or RNDIS filters */
        if (!eth_is_promisc (dev)) {
                u8              *dest = skb->data;

                if (is_multicast_ether_addr(dest)) {
                        u16     type;

                        /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
                         * SET_ETHERNET_MULTICAST_FILTERS requests
                         */
                        if (is_broadcast_ether_addr(dest))
                                type = USB_CDC_PACKET_TYPE_BROADCAST;
                        else
                                type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
                        if (!(dev->cdc_filter & type)) {
                                dev_kfree_skb_any (skb);
                                return 0;
                        }
                }
                /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
        }

        spin_lock_irqsave(&dev->req_lock, flags);
        /*
         * this freelist can be empty if an interrupt triggered disconnect()
         * and reconfigured the gadget (shutting down this queue) after the
         * network stack decided to xmit but before we got the spinlock.
         */
        if (list_empty(&dev->tx_reqs)) {
                spin_unlock_irqrestore(&dev->req_lock, flags);
                return 1;
        }

        req = container_of (dev->tx_reqs.next, struct usb_request, list);
        list_del (&req->list);

        /* temporarily stop TX queue when the freelist empties */
        if (list_empty (&dev->tx_reqs))
                netif_stop_queue (net);
        spin_unlock_irqrestore(&dev->req_lock, flags);

        /* no buffer copies needed, unless the network stack did it
         * or the hardware can't use skb buffers.
         * or there's not enough space for any RNDIS headers we need
         */
        if (rndis_active(dev)) {
                struct sk_buff  *skb_rndis;

                skb_rndis = skb_realloc_headroom (skb,
                                sizeof (struct rndis_packet_msg_type));
                if (!skb_rndis)
                        goto drop;

                dev_kfree_skb_any (skb);
                skb = skb_rndis;
                rndis_add_hdr (skb);
                length = skb->len;
        }
        req->buf = skb->data;
        req->context = skb;
        req->complete = tx_complete;

        /* use zlp framing on tx for strict CDC-Ether conformance,
         * though any robust network rx path ignores extra padding.
         * and some hardware doesn't like to write zlps.
         */
        req->zero = 1;
        if (!dev->zlp && (length % dev->in_ep->maxpacket) == 0)
                length++;

        req->length = length;

        /* throttle highspeed IRQ rate back slightly */
        if (gadget_is_dualspeed(dev->gadget))
                req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH)
                        ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
                        : 0;

        retval = usb_ep_queue (dev->in_ep, req, GFP_ATOMIC);
        switch (retval) {
        default:
                DEBUG (dev, "tx queue err %d\n", retval);
                break;
        case 0:
                net->trans_start = jiffies;
                atomic_inc (&dev->tx_qlen);
        }

        if (retval) {
drop:
                dev->stats.tx_dropped++;
                dev_kfree_skb_any (skb);
                spin_lock_irqsave(&dev->req_lock, flags);
                if (list_empty (&dev->tx_reqs))
                        netif_start_queue (net);
                list_add (&req->list, &dev->tx_reqs);
                spin_unlock_irqrestore(&dev->req_lock, flags);
        }
        return 0;
}

/*-------------------------------------------------------------------------*/
#endif

static void eth_unbind(struct usb_gadget *gadget)
{
        struct eth_dev *dev = get_gadget_data(gadget);

        debug("%s...\n", __func__);

        /* we've already been disconnected ... no i/o is active */
        if (dev->req) {
                usb_ep_free_request(gadget->ep0, dev->req);
                dev->req = NULL;
        }
        if (dev->stat_req) {
                usb_ep_free_request(dev->status_ep, dev->stat_req);
                dev->stat_req = NULL;
        }

        if (dev->tx_req) {
                usb_ep_free_request(dev->in_ep, dev->tx_req);
                dev->tx_req = NULL;
        }

        if (dev->rx_req) {
                usb_ep_free_request(dev->out_ep, dev->rx_req);
                dev->rx_req = NULL;
        }

/*      unregister_netdev (dev->net);*/
/*      free_netdev(dev->net);*/

        dev->gadget = NULL;
        set_gadget_data(gadget, NULL);
}

static void eth_disconnect(struct usb_gadget *gadget)
{
        eth_reset_config(get_gadget_data(gadget));
}

static void eth_suspend(struct usb_gadget *gadget)
{
        /* Not used */
}

static void eth_resume(struct usb_gadget *gadget)
{
        /* Not used */
}

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

static int is_eth_addr_valid(char *str)
{
        if (strlen(str) == 17) {
                int i;
                char *p, *q;
                uchar ea[6];

                /* see if it looks like an ethernet address */

                p = str;

                for (i = 0; i < 6; i++) {
                        char term = (i == 5 ? '\0' : ':');

                        ea[i] = simple_strtol(p, &q, 16);

                        if ((q - p) != 2 || *q++ != term)
                                break;

                        p = q;
                }

                if (i == 6) /* it looks ok */
                        return 1;
        }
        return 0;
}

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 int get_ether_addr(const char *str, u8 *dev_addr)
{
        if (str) {
                unsigned        i;

                for (i = 0; i < 6; i++) {
                        unsigned char num;

                        if ((*str == '.') || (*str == ':'))
                                str++;
                        num = nibble(*str++) << 4;
                        num |= (nibble(*str++));
                        dev_addr[i] = num;
                }
                if (is_valid_ether_addr(dev_addr))
                        return 0;
        }
        return 1;
}

static int eth_bind(struct usb_gadget *gadget)
{
        struct eth_dev          *dev = &l_ethdev;
        u8                      cdc = 1, zlp = 1;
        struct usb_ep           *in_ep, *out_ep, *status_ep = NULL;
        int                     gcnum;
        u8                      tmp[7];

        /* these flags are only ever cleared; compiler take note */
#ifndef DEV_CONFIG_CDC
        cdc = 0;
#endif
        /*
         * Because most host side USB stacks handle CDC Ethernet, that
         * standard protocol is _strongly_ preferred for interop purposes.
         * (By everyone except Microsoft.)
         */
        if (gadget_is_pxa(gadget)) {
                /* pxa doesn't support altsettings */
                cdc = 0;
        } else if (gadget_is_musbhdrc(gadget)) {
                /* reduce tx dma overhead by avoiding special cases */
                zlp = 0;
        } else if (gadget_is_sh(gadget)) {
                /* sh doesn't support multiple interfaces or configs */
                cdc = 0;
        } else if (gadget_is_sa1100(gadget)) {
                /* hardware can't write zlps */
                zlp = 0;
                /*
                 * sa1100 CAN do CDC, without status endpoint ... we use
                 * non-CDC to be compatible with ARM Linux-2.4 "usb-eth".
                 */
                cdc = 0;
        }

        gcnum = usb_gadget_controller_number(gadget);
        if (gcnum >= 0)
                device_desc.bcdDevice = cpu_to_le16(0x0300 + gcnum);
        else {
                /*
                 * can't assume CDC works.  don't want to default to
                 * anything less functional on CDC-capable hardware,
                 * so we fail in this case.
                 */
                error("controller '%s' not recognized",
                        gadget->name);
                return -ENODEV;
        }

        /*
         * CDC subset ... recognized by Linux since 2.4.10, but Windows
         * drivers aren't widely available.  (That may be improved by
         * supporting one submode of the "SAFE" variant of MDLM.)
         */
        if (!cdc) {
                device_desc.idVendor =
                        __constant_cpu_to_le16(SIMPLE_VENDOR_NUM);
                device_desc.idProduct =
                        __constant_cpu_to_le16(SIMPLE_PRODUCT_NUM);
        }

        /* support optional vendor/distro customization */
#if defined(CONFIG_USB_CDC_VENDOR_ID) && defined(CONFIG_USB_CDC_PRODUCT_ID)
        device_desc.idVendor = cpu_to_le16(CONFIG_USB_CDC_VENDOR_ID);
        device_desc.idProduct = cpu_to_le16(CONFIG_USB_CDC_PRODUCT_ID);
#endif
        if (bcdDevice)
                device_desc.bcdDevice = cpu_to_le16(bcdDevice);
        if (iManufacturer)
                strlcpy(manufacturer, iManufacturer, sizeof manufacturer);
        if (iProduct)
                strlcpy(product_desc, iProduct, sizeof product_desc);
        if (iSerialNumber) {
                device_desc.iSerialNumber = STRING_SERIALNUMBER,
                strlcpy(serial_number, iSerialNumber, sizeof serial_number);
        }

        /* all we really need is bulk IN/OUT */
        usb_ep_autoconfig_reset(gadget);
        in_ep = usb_ep_autoconfig(gadget, &fs_source_desc);
        if (!in_ep) {
autoconf_fail:
                error("can't autoconfigure on %s\n",
                        gadget->name);
                return -ENODEV;
        }
        in_ep->driver_data = in_ep;     /* claim */

        out_ep = usb_ep_autoconfig(gadget, &fs_sink_desc);
        if (!out_ep)
                goto autoconf_fail;
        out_ep->driver_data = out_ep;   /* claim */

#if defined(DEV_CONFIG_CDC)
        /*
         * CDC Ethernet control interface doesn't require a status endpoint.
         * Since some hosts expect one, try to allocate one anyway.
         */
        if (cdc) {
                status_ep = usb_ep_autoconfig(gadget, &fs_status_desc);
                if (status_ep) {
                        status_ep->driver_data = status_ep;     /* claim */
                } else if (cdc) {
                        control_intf.bNumEndpoints = 0;
                        /* FIXME remove endpoint from descriptor list */
                }
        }
#endif

        /* one config:  cdc, else minimal subset */
        if (!cdc) {
                eth_config.bNumInterfaces = 1;
                eth_config.iConfiguration = STRING_SUBSET;

                /*
                 * use functions to set these up, in case we're built to work
                 * with multiple controllers and must override CDC Ethernet.
                 */
                fs_subset_descriptors();
                hs_subset_descriptors();
        }

        device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
        usb_gadget_set_selfpowered(gadget);

        if (gadget_is_dualspeed(gadget)) {
                if (!cdc)
                        dev_qualifier.bDeviceClass = USB_CLASS_VENDOR_SPEC;

                /* assumes ep0 uses the same value for both speeds ... */
                dev_qualifier.bMaxPacketSize0 = device_desc.bMaxPacketSize0;

                /* and that all endpoints are dual-speed */
                hs_source_desc.bEndpointAddress =
                                fs_source_desc.bEndpointAddress;
                hs_sink_desc.bEndpointAddress =
                                fs_sink_desc.bEndpointAddress;
#if defined(DEV_CONFIG_CDC)
                if (status_ep)
                        hs_status_desc.bEndpointAddress =
                                        fs_status_desc.bEndpointAddress;
#endif
        }

        if (gadget_is_otg(gadget)) {
                otg_descriptor.bmAttributes |= USB_OTG_HNP,
                eth_config.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
                eth_config.bMaxPower = 4;
        }

        dev->net = &l_netdev;

        dev->cdc = cdc;
        dev->zlp = zlp;

        dev->in_ep = in_ep;
        dev->out_ep = out_ep;
        dev->status_ep = status_ep;

        /*
         * Module params for these addresses should come from ID proms.
         * The host side address is used with CDC, and commonly
         * ends up in a persistent config database.  It's not clear if
         * host side code for the SAFE thing cares -- its original BLAN
         * thing didn't, Sharp never assigned those addresses on Zaurii.
         */
        get_ether_addr(dev_addr, dev->net->enetaddr);

        memset(tmp, 0, sizeof(tmp));
        memcpy(tmp, dev->net->enetaddr, sizeof(dev->net->enetaddr));

        get_ether_addr(host_addr, dev->host_mac);

        sprintf(ethaddr, "%02X%02X%02X%02X%02X%02X",
                dev->host_mac[0], dev->host_mac[1],
                        dev->host_mac[2], dev->host_mac[3],
                        dev->host_mac[4], dev->host_mac[5]);

        printf("using %s, OUT %s IN %s%s%s\n", gadget->name,
                out_ep->name, in_ep->name,
                status_ep ? " STATUS " : "",
                status_ep ? status_ep->name : ""
                );
        printf("MAC %02x:%02x:%02x:%02x:%02x:%02x\n",
                dev->net->enetaddr[0], dev->net->enetaddr[1],
                dev->net->enetaddr[2], dev->net->enetaddr[3],
                dev->net->enetaddr[4], dev->net->enetaddr[5]);

        if (cdc) {
                printf("HOST MAC %02x:%02x:%02x:%02x:%02x:%02x\n",
                        dev->host_mac[0], dev->host_mac[1],
                        dev->host_mac[2], dev->host_mac[3],
                        dev->host_mac[4], dev->host_mac[5]);
        }

        /*
         * use PKTSIZE (or aligned... from u-boot) and set
         * wMaxSegmentSize accordingly
         */
        dev->mtu = PKTSIZE_ALIGN; /* RNDIS does not like this, only 1514, TODO*/

        /* preallocate control message data and buffer */
        dev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
        if (!dev->req)
                goto fail;
        dev->req->buf = control_req;
        dev->req->complete = eth_setup_complete;

        /* ... and maybe likewise for status transfer */
#if defined(DEV_CONFIG_CDC)
        if (dev->status_ep) {
                dev->stat_req = usb_ep_alloc_request(dev->status_ep,
                                                        GFP_KERNEL);
                if (!dev->stat_req) {
                        usb_ep_free_request(dev->status_ep, dev->req);

                        goto fail;
                }
                dev->stat_req->buf = status_req;
                dev->stat_req->context = NULL;
        }
#endif

        /* finish hookup to lower layer ... */
        dev->gadget = gadget;
        set_gadget_data(gadget, dev);
        gadget->ep0->driver_data = dev;

        /*
         * two kinds of host-initiated state changes:
         *  - iff DATA transfer is active, carrier is "on"
         *  - tx queueing enabled if open *and* carrier is "on"
         */
        return 0;

fail:
        error("%s failed", __func__);
        eth_unbind(gadget);
        return -ENOMEM;
}

static int usb_eth_init(struct eth_device *netdev, bd_t *bd)
{
        struct eth_dev *dev = &l_ethdev;
        struct usb_gadget *gadget;
        unsigned long ts;
        unsigned long timeout = USB_CONNECT_TIMEOUT;

        if (!netdev) {
                error("received NULL ptr");
                goto fail;
        }

        /* Configure default mac-addresses for the USB ethernet device */
#ifdef CONFIG_USBNET_DEV_ADDR
        strlcpy(dev_addr, CONFIG_USBNET_DEV_ADDR, sizeof(dev_addr));
#endif
#ifdef CONFIG_USBNET_HOST_ADDR
        strlcpy(host_addr, CONFIG_USBNET_HOST_ADDR, sizeof(host_addr));
#endif
        /* Check if the user overruled the MAC addresses */
        if (getenv("usbnet_devaddr"))
                strlcpy(dev_addr, getenv("usbnet_devaddr"),
                        sizeof(dev_addr));

        if (getenv("usbnet_hostaddr"))
                strlcpy(host_addr, getenv("usbnet_hostaddr"),
                        sizeof(host_addr));

        if (!is_eth_addr_valid(dev_addr)) {
                error("Need valid 'usbnet_devaddr' to be set");
                goto fail;
        }
        if (!is_eth_addr_valid(host_addr)) {
                error("Need valid 'usbnet_hostaddr' to be set");
                goto fail;
        }

        if (usb_gadget_register_driver(&eth_driver) < 0)
                goto fail;

        dev->network_started = 0;

        packet_received = 0;
        packet_sent = 0;

        gadget = dev->gadget;
        usb_gadget_connect(gadget);

        if (getenv("cdc_connect_timeout"))
                timeout = simple_strtoul(getenv("cdc_connect_timeout"),
                                                NULL, 10) * CONFIG_SYS_HZ;
        ts = get_timer(0);
        while (!l_ethdev.network_started) {
                /* Handle control-c and timeouts */
                if (ctrlc() || (get_timer(ts) > timeout)) {
                        error("The remote end did not respond in time.");
                        goto fail;
                }
                usb_gadget_handle_interrupts();
        }

        packet_received = 0;
        rx_submit(dev, dev->rx_req, 0);
        return 0;
fail:
        return -1;
}

static int usb_eth_send(struct eth_device *netdev,
                        volatile void *packet, int length)
{
        int                     retval;
        struct eth_dev          *dev = &l_ethdev;
        struct usb_request      *req = dev->tx_req;
        unsigned long ts;
        unsigned long timeout = USB_CONNECT_TIMEOUT;

        debug("%s:...\n", __func__);

        req->buf = (void *)packet;
        req->context = NULL;
        req->complete = tx_complete;

        /*
         * use zlp framing on tx for strict CDC-Ether conformance,
         * though any robust network rx path ignores extra padding.
         * and some hardware doesn't like to write zlps.
         */
        req->zero = 1;
        if (!dev->zlp && (length % dev->in_ep->maxpacket) == 0)
                length++;

        req->length = length;
#if 0
        /* throttle highspeed IRQ rate back slightly */
        if (gadget_is_dualspeed(dev->gadget))
                req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH)
                        ? ((dev->tx_qlen % qmult) != 0) : 0;
#endif
        dev->tx_qlen = 1;
        ts = get_timer(0);
        packet_sent = 0;

        retval = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);

        if (!retval)
                debug("%s: packet queued\n", __func__);
        while (!packet_sent) {
                if (get_timer(ts) > timeout) {
                        printf("timeout sending packets to usb ethernet\n");
                        return -1;
                }
                usb_gadget_handle_interrupts();
        }

        return 0;
}

static int usb_eth_recv(struct eth_device *netdev)
{
        struct eth_dev *dev = &l_ethdev;

        usb_gadget_handle_interrupts();

        if (packet_received) {
                debug("%s: packet received\n", __func__);
                if (dev->rx_req) {
                        NetReceive(NetRxPackets[0], dev->rx_req->length);
                        packet_received = 0;

                        rx_submit(dev, dev->rx_req, 0);
                } else
                        error("dev->rx_req invalid");
        }
        return 0;
}

void usb_eth_halt(struct eth_device *netdev)
{
        struct eth_dev *dev = &l_ethdev;

        if (!netdev) {
                error("received NULL ptr");
                return;
        }

        /* If the gadget not registered, simple return */
        if (!dev->gadget)
                return;

        usb_gadget_disconnect(dev->gadget);

        /* Clear pending interrupt */
        if (dev->network_started) {
                usb_gadget_handle_interrupts();
                dev->network_started = 0;
        }

        usb_gadget_unregister_driver(&eth_driver);
}

static struct usb_gadget_driver eth_driver = {
        .speed          = DEVSPEED,

        .bind           = eth_bind,
        .unbind         = eth_unbind,

        .setup          = eth_setup,
        .disconnect     = eth_disconnect,

        .suspend        = eth_suspend,
        .resume         = eth_resume,
};

int usb_eth_initialize(bd_t *bi)
{
        struct eth_device *netdev = &l_netdev;

        strlcpy(netdev->name, USB_NET_NAME, sizeof(netdev->name));

        netdev->init = usb_eth_init;
        netdev->send = usb_eth_send;
        netdev->recv = usb_eth_recv;
        netdev->halt = usb_eth_halt;

#ifdef CONFIG_MCAST_TFTP
  #error not supported
#endif
        eth_register(netdev);
        return 0;
}