drivers/usb/net/net1080.c

   1 /*
   2  * Net1080 based USB host-to-host cables
   3  * Copyright (C) 2000-2005 by David Brownell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 // #define      DEBUG                   // error path messages, extra info
  21 // #define      VERBOSE                 // more; success messages
  22
  23 #include <linux/config.h>
  24 #include <linux/module.h>
  25 #include <linux/sched.h>
  26 #include <linux/init.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/ethtool.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/mii.h>
  32 #include <linux/usb.h>
  33
  34 #include <asm/unaligned.h>
  35
  36 #include "usbnet.h"
  37
  38
  39 /*
  40  * Netchip 1080 driver ... http://www.netchip.com
  41  * (Sept 2004:  End-of-life announcement has been sent.)
  42  * Used in (some) LapLink cables
  43  */
  44
  45 #define frame_errors    data[1]
  46
  47 /*
  48  * NetChip framing of ethernet packets, supporting additional error
  49  * checks for links that may drop bulk packets from inside messages.
  50  * Odd USB length == always short read for last usb packet.
  51  *      - nc_header
  52  *      - Ethernet header (14 bytes)
  53  *      - payload
  54  *      - (optional padding byte, if needed so length becomes odd)
  55  *      - nc_trailer
  56  *
  57  * This framing is to be avoided for non-NetChip devices.
  58  */
  59
  60 struct nc_header {              // packed:
  61         __le16  hdr_len;                // sizeof nc_header (LE, all)
  62         __le16  packet_len;             // payload size (including ethhdr)
  63         __le16  packet_id;              // detects dropped packets
  64 #define MIN_HEADER      6
  65
  66         // all else is optional, and must start with:
  67         // __le16       vendorId;       // from usb-if
  68         // __le16       productId;
  69 } __attribute__((__packed__));
  70
  71 #define PAD_BYTE        ((unsigned char)0xAC)
  72
  73 struct nc_trailer {
  74         __le16  packet_id;
  75 } __attribute__((__packed__));
  76
  77 // packets may use FLAG_FRAMING_NC and optional pad
  78 #define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
  79                                 + sizeof (struct ethhdr) \
  80                                 + (mtu) \
  81                                 + 1 \
  82                                 + sizeof (struct nc_trailer))
  83
  84 #define MIN_FRAMED      FRAMED_SIZE(0)
  85
  86 /* packets _could_ be up to 64KB... */
  87 #define NC_MAX_PACKET   32767
  88
  89
  90 /*
  91  * Zero means no timeout; else, how long a 64 byte bulk packet may be queued
  92  * before the hardware drops it.  If that's done, the driver will need to
  93  * frame network packets to guard against the dropped USB packets.  The win32
  94  * driver sets this for both sides of the link.
  95  */
  96 #define NC_READ_TTL_MS  ((u8)255)       // ms
  97
  98 /*
  99  * We ignore most registers and EEPROM contents.
 100  */
 101 #define REG_USBCTL      ((u8)0x04)
 102 #define REG_TTL         ((u8)0x10)
 103 #define REG_STATUS      ((u8)0x11)
 104
 105 /*
 106  * Vendor specific requests to read/write data
 107  */
 108 #define REQUEST_REGISTER        ((u8)0x10)
 109 #define REQUEST_EEPROM          ((u8)0x11)
 110
 111 static int
 112 nc_vendor_read(struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
 113 {
 114         int status = usb_control_msg(dev->udev,
 115                 usb_rcvctrlpipe(dev->udev, 0),
 116                 req,
 117                 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 118                 0, regnum,
 119                 retval_ptr, sizeof *retval_ptr,
 120                 USB_CTRL_GET_TIMEOUT);
 121         if (status > 0)
 122                 status = 0;
 123         if (!status)
 124                 le16_to_cpus(retval_ptr);
 125         return status;
 126 }
 127
 128 static inline int
 129 nc_register_read(struct usbnet *dev, u8 regnum, u16 *retval_ptr)
 130 {
 131         return nc_vendor_read(dev, REQUEST_REGISTER, regnum, retval_ptr);
 132 }
 133
 134 // no retval ... can become async, usable in_interrupt()
 135 static void
 136 nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value)
 137 {
 138         usb_control_msg(dev->udev,
 139                 usb_sndctrlpipe(dev->udev, 0),
 140                 req,
 141                 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 142                 value, regnum,
 143                 NULL, 0,                        // data is in setup packet
 144                 USB_CTRL_SET_TIMEOUT);
 145 }
 146
 147 static inline void
 148 nc_register_write(struct usbnet *dev, u8 regnum, u16 value)
 149 {
 150         nc_vendor_write(dev, REQUEST_REGISTER, regnum, value);
 151 }
 152
 153
 154 #if 0
 155 static void nc_dump_registers(struct usbnet *dev)
 156 {
 157         u8      reg;
 158         u16     *vp = kmalloc(sizeof (u16));
 159
 160         if (!vp) {
 161                 dbg("no memory?");
 162                 return;
 163         }
 164
 165         dbg("%s registers:", dev->net->name);
 166         for (reg = 0; reg < 0x20; reg++) {
 167                 int retval;
 168
 169                 // reading some registers is trouble
 170                 if (reg >= 0x08 && reg <= 0xf)
 171                         continue;
 172                 if (reg >= 0x12 && reg <= 0x1e)
 173                         continue;
 174
 175                 retval = nc_register_read(dev, reg, vp);
 176                 if (retval < 0)
 177                         dbg("%s reg [0x%x] ==> error %d",
 178                                 dev->net->name, reg, retval);
 179                 else
 180                         dbg("%s reg [0x%x] = 0x%x",
 181                                 dev->net->name, reg, *vp);
 182         }
 183         kfree(vp);
 184 }
 185 #endif
 186
 187
 188 /*-------------------------------------------------------------------------*/
 189
 190 /*
 191  * Control register
 192  */
 193
 194 #define USBCTL_WRITABLE_MASK    0x1f0f
 195 // bits 15-13 reserved, r/o
 196 #define USBCTL_ENABLE_LANG      (1 << 12)
 197 #define USBCTL_ENABLE_MFGR      (1 << 11)
 198 #define USBCTL_ENABLE_PROD      (1 << 10)
 199 #define USBCTL_ENABLE_SERIAL    (1 << 9)
 200 #define USBCTL_ENABLE_DEFAULTS  (1 << 8)
 201 // bits 7-4 reserved, r/o
 202 #define USBCTL_FLUSH_OTHER      (1 << 3)
 203 #define USBCTL_FLUSH_THIS       (1 << 2)
 204 #define USBCTL_DISCONN_OTHER    (1 << 1)
 205 #define USBCTL_DISCONN_THIS     (1 << 0)
 206
 207 static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
 208 {
 209         if (!netif_msg_link(dev))
 210                 return;
 211         devdbg(dev, "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s;"
 212                         " this%s%s;"
 213                         " other%s%s; r/o 0x%x",
 214                 dev->udev->bus->bus_name, dev->udev->devpath,
 215                 usbctl,
 216                 (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
 217                 (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
 218                 (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
 219                 (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
 220                 (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
 221
 222                 (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
 223                 (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
 224                 (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
 225                 (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
 226                 usbctl & ~USBCTL_WRITABLE_MASK
 227                 );
 228 }
 229
 230 /*-------------------------------------------------------------------------*/
 231
 232 /*
 233  * Status register
 234  */
 235
 236 #define STATUS_PORT_A           (1 << 15)
 237
 238 #define STATUS_CONN_OTHER       (1 << 14)
 239 #define STATUS_SUSPEND_OTHER    (1 << 13)
 240 #define STATUS_MAILBOX_OTHER    (1 << 12)
 241 #define STATUS_PACKETS_OTHER(n) (((n) >> 8) && 0x03)
 242
 243 #define STATUS_CONN_THIS        (1 << 6)
 244 #define STATUS_SUSPEND_THIS     (1 << 5)
 245 #define STATUS_MAILBOX_THIS     (1 << 4)
 246 #define STATUS_PACKETS_THIS(n)  (((n) >> 0) && 0x03)
 247
 248 #define STATUS_UNSPEC_MASK      0x0c8c
 249 #define STATUS_NOISE_MASK       ((u16)~(0x0303|STATUS_UNSPEC_MASK))
 250
 251
 252 static inline void nc_dump_status(struct usbnet *dev, u16 status)
 253 {
 254         if (!netif_msg_link(dev))
 255                 return;
 256         devdbg(dev, "net1080 %s-%s status 0x%x:"
 257                         " this (%c) PKT=%d%s%s%s;"
 258                         " other PKT=%d%s%s%s; unspec 0x%x",
 259                 dev->udev->bus->bus_name, dev->udev->devpath,
 260                 status,
 261
 262                 // XXX the packet counts don't seem right
 263                 // (1 at reset, not 0); maybe UNSPEC too
 264
 265                 (status & STATUS_PORT_A) ? 'A' : 'B',
 266                 STATUS_PACKETS_THIS(status),
 267                 (status & STATUS_CONN_THIS) ? " CON" : "",
 268                 (status & STATUS_SUSPEND_THIS) ? " SUS" : "",
 269                 (status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
 270
 271                 STATUS_PACKETS_OTHER(status),
 272                 (status & STATUS_CONN_OTHER) ? " CON" : "",
 273                 (status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
 274                 (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
 275
 276                 status & STATUS_UNSPEC_MASK
 277                 );
 278 }
 279
 280 /*-------------------------------------------------------------------------*/
 281
 282 /*
 283  * TTL register
 284  */
 285
 286 #define TTL_THIS(ttl)   (0x00ff & ttl)
 287 #define TTL_OTHER(ttl)  (0x00ff & (ttl >> 8))
 288 #define MK_TTL(this,other)      ((u16)(((other)<<8)|(0x00ff&(this))))
 289
 290 static inline void nc_dump_ttl(struct usbnet *dev, u16 ttl)
 291 {
 292         if (netif_msg_link(dev))
 293                 devdbg(dev, "net1080 %s-%s ttl 0x%x this = %d, other = %d",
 294                         dev->udev->bus->bus_name, dev->udev->devpath,
 295                         ttl, TTL_THIS(ttl), TTL_OTHER(ttl));
 296 }
 297
 298 /*-------------------------------------------------------------------------*/
 299
 300 static int net1080_reset(struct usbnet *dev)
 301 {
 302         u16             usbctl, status, ttl;
 303         u16             *vp = kmalloc(sizeof (u16), GFP_KERNEL);
 304         int             retval;
 305
 306         if (!vp)
 307                 return -ENOMEM;
 308
 309         // nc_dump_registers(dev);
 310
 311         if ((retval = nc_register_read(dev, REG_STATUS, vp)) < 0) {
 312                 dbg("can't read %s-%s status: %d",
 313                         dev->udev->bus->bus_name, dev->udev->devpath, retval);
 314                 goto done;
 315         }
 316         status = *vp;
 317         nc_dump_status(dev, status);
 318
 319         if ((retval = nc_register_read(dev, REG_USBCTL, vp)) < 0) {
 320                 dbg("can't read USBCTL, %d", retval);
 321                 goto done;
 322         }
 323         usbctl = *vp;
 324         nc_dump_usbctl(dev, usbctl);
 325
 326         nc_register_write(dev, REG_USBCTL,
 327                         USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
 328
 329         if ((retval = nc_register_read(dev, REG_TTL, vp)) < 0) {
 330                 dbg("can't read TTL, %d", retval);
 331                 goto done;
 332         }
 333         ttl = *vp;
 334         // nc_dump_ttl(dev, ttl);
 335
 336         nc_register_write(dev, REG_TTL,
 337                         MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
 338         dbg("%s: assigned TTL, %d ms", dev->net->name, NC_READ_TTL_MS);
 339
 340         if (netif_msg_link(dev))
 341                 devinfo(dev, "port %c, peer %sconnected",
 342                         (status & STATUS_PORT_A) ? 'A' : 'B',
 343                         (status & STATUS_CONN_OTHER) ? "" : "dis"
 344                         );
 345         retval = 0;
 346
 347 done:
 348         kfree(vp);
 349         return retval;
 350 }
 351
 352 static int net1080_check_connect(struct usbnet *dev)
 353 {
 354         int                     retval;
 355         u16                     status;
 356         u16                     *vp = kmalloc(sizeof (u16), GFP_KERNEL);
 357
 358         if (!vp)
 359                 return -ENOMEM;
 360         retval = nc_register_read(dev, REG_STATUS, vp);
 361         status = *vp;
 362         kfree(vp);
 363         if (retval != 0) {
 364                 dbg("%s net1080_check_conn read - %d", dev->net->name, retval);
 365                 return retval;
 366         }
 367         if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
 368                 return -ENOLINK;
 369         return 0;
 370 }
 371
 372 static void nc_flush_complete(struct urb *urb, struct pt_regs *regs)
 373 {
 374         kfree(urb->context);
 375         usb_free_urb(urb);
 376 }
 377
 378 static void nc_ensure_sync(struct usbnet *dev)
 379 {
 380         dev->frame_errors++;
 381         if (dev->frame_errors > 5) {
 382                 struct urb              *urb;
 383                 struct usb_ctrlrequest  *req;
 384                 int                     status;
 385
 386                 /* Send a flush */
 387                 urb = usb_alloc_urb(0, SLAB_ATOMIC);
 388                 if (!urb)
 389                         return;
 390
 391                 req = kmalloc(sizeof *req, GFP_ATOMIC);
 392                 if (!req) {
 393                         usb_free_urb(urb);
 394                         return;
 395                 }
 396
 397                 req->bRequestType = USB_DIR_OUT
 398                         | USB_TYPE_VENDOR
 399                         | USB_RECIP_DEVICE;
 400                 req->bRequest = REQUEST_REGISTER;
 401                 req->wValue = cpu_to_le16(USBCTL_FLUSH_THIS
 402                                 | USBCTL_FLUSH_OTHER);
 403                 req->wIndex = cpu_to_le16(REG_USBCTL);
 404                 req->wLength = cpu_to_le16(0);
 405
 406                 /* queue an async control request, we don't need
 407                  * to do anything when it finishes except clean up.
 408                  */
 409                 usb_fill_control_urb(urb, dev->udev,
 410                         usb_sndctrlpipe(dev->udev, 0),
 411                         (unsigned char *) req,
 412                         NULL, 0,
 413                         nc_flush_complete, req);
 414                 status = usb_submit_urb(urb, GFP_ATOMIC);
 415                 if (status) {
 416                         kfree(req);
 417                         usb_free_urb(urb);
 418                         return;
 419                 }
 420
 421                 if (netif_msg_rx_err(dev))
 422                         devdbg(dev, "flush net1080; too many framing errors");
 423                 dev->frame_errors = 0;
 424         }
 425 }
 426
 427 static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 428 {
 429         struct nc_header        *header;
 430         struct nc_trailer       *trailer;
 431         u16                     hdr_len, packet_len;
 432
 433         if (!(skb->len & 0x01)) {
 434 #ifdef DEBUG
 435                 struct net_device       *net = dev->net;
 436                 dbg("rx framesize %d range %d..%d mtu %d", skb->len,
 437                         net->hard_header_len, dev->hard_mtu, net->mtu);
 438 #endif
 439                 dev->stats.rx_frame_errors++;
 440                 nc_ensure_sync(dev);
 441                 return 0;
 442         }
 443
 444         header = (struct nc_header *) skb->data;
 445         hdr_len = le16_to_cpup(&header->hdr_len);
 446         packet_len = le16_to_cpup(&header->packet_len);
 447         if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
 448                 dev->stats.rx_frame_errors++;
 449                 dbg("packet too big, %d", packet_len);
 450                 nc_ensure_sync(dev);
 451                 return 0;
 452         } else if (hdr_len < MIN_HEADER) {
 453                 dev->stats.rx_frame_errors++;
 454                 dbg("header too short, %d", hdr_len);
 455                 nc_ensure_sync(dev);
 456                 return 0;
 457         } else if (hdr_len > MIN_HEADER) {
 458                 // out of band data for us?
 459                 dbg("header OOB, %d bytes", hdr_len - MIN_HEADER);
 460                 nc_ensure_sync(dev);
 461                 // switch (vendor/product ids) { ... }
 462         }
 463         skb_pull(skb, hdr_len);
 464
 465         trailer = (struct nc_trailer *)
 466                 (skb->data + skb->len - sizeof *trailer);
 467         skb_trim(skb, skb->len - sizeof *trailer);
 468
 469         if ((packet_len & 0x01) == 0) {
 470                 if (skb->data [packet_len] != PAD_BYTE) {
 471                         dev->stats.rx_frame_errors++;
 472                         dbg("bad pad");
 473                         return 0;
 474                 }
 475                 skb_trim(skb, skb->len - 1);
 476         }
 477         if (skb->len != packet_len) {
 478                 dev->stats.rx_frame_errors++;
 479                 dbg("bad packet len %d (expected %d)",
 480                         skb->len, packet_len);
 481                 nc_ensure_sync(dev);
 482                 return 0;
 483         }
 484         if (header->packet_id != get_unaligned(&trailer->packet_id)) {
 485                 dev->stats.rx_fifo_errors++;
 486                 dbg("(2+ dropped) rx packet_id mismatch 0x%x 0x%x",
 487                         le16_to_cpu(header->packet_id),
 488                         le16_to_cpu(trailer->packet_id));
 489                 return 0;
 490         }
 491 #if 0
 492         devdbg(dev, "frame <rx h %d p %d id %d", header->hdr_len,
 493                 header->packet_len, header->packet_id);
 494 #endif
 495         dev->frame_errors = 0;
 496         return 1;
 497 }
 498
 499 static struct sk_buff *
 500 net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 501 {
 502         int                     padlen;
 503         struct sk_buff          *skb2;
 504         struct nc_header        *header = NULL;
 505         struct nc_trailer       *trailer = NULL;
 506         int                     len = skb->len;
 507
 508         padlen = ((len + sizeof (struct nc_header)
 509                         + sizeof (struct nc_trailer)) & 0x01) ? 0 : 1;
 510         if (!skb_cloned(skb)) {
 511                 int     headroom = skb_headroom(skb);
 512                 int     tailroom = skb_tailroom(skb);
 513
 514                 if ((padlen + sizeof (struct nc_trailer)) <= tailroom
 515                             && sizeof (struct nc_header) <= headroom)
 516                         /* There's enough head and tail room */
 517                         goto encapsulate;
 518
 519                 if ((sizeof (struct nc_header) + padlen
 520                                         + sizeof (struct nc_trailer)) <
 521                                 (headroom + tailroom)) {
 522                         /* There's enough total room, so just readjust */
 523                         skb->data = memmove(skb->head
 524                                                 + sizeof (struct nc_header),
 525                                             skb->data, skb->len);
 526                         skb->tail = skb->data + len;
 527                         goto encapsulate;
 528                 }
 529         }
 530
 531         /* Create a new skb to use with the correct size */
 532         skb2 = skb_copy_expand(skb,
 533                                 sizeof (struct nc_header),
 534                                 sizeof (struct nc_trailer) + padlen,
 535                                 flags);
 536         dev_kfree_skb_any(skb);
 537         if (!skb2)
 538                 return skb2;
 539         skb = skb2;
 540
 541 encapsulate:
 542         /* header first */
 543         header = (struct nc_header *) skb_push(skb, sizeof *header);
 544         header->hdr_len = cpu_to_le16(sizeof (*header));
 545         header->packet_len = cpu_to_le16(len);
 546         header->packet_id = cpu_to_le16((u16)dev->xid++);
 547
 548         /* maybe pad; then trailer */
 549         if (!((skb->len + sizeof *trailer) & 0x01))
 550                 *skb_put(skb, 1) = PAD_BYTE;
 551         trailer = (struct nc_trailer *) skb_put(skb, sizeof *trailer);
 552         put_unaligned(header->packet_id, &trailer->packet_id);
 553 #if 0
 554         devdbg(dev, "frame >tx h %d p %d id %d",
 555                 header->hdr_len, header->packet_len,
 556                 header->packet_id);
 557 #endif
 558         return skb;
 559 }
 560
 561 static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
 562 {
 563         unsigned        extra = sizeof (struct nc_header)
 564                                 + 1
 565                                 + sizeof (struct nc_trailer);
 566
 567         dev->net->hard_header_len += extra;
 568         dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
 569         dev->hard_mtu = NC_MAX_PACKET;
 570         return usbnet_get_endpoints (dev, intf);
 571 }
 572
 573 static const struct driver_info net1080_info = {
 574         .description =  "NetChip TurboCONNECT",
 575         .flags =        FLAG_FRAMING_NC,
 576         .bind =         net1080_bind,
 577         .reset =        net1080_reset,
 578         .check_connect = net1080_check_connect,
 579         .rx_fixup =     net1080_rx_fixup,
 580         .tx_fixup =     net1080_tx_fixup,
 581 };
 582
 583 static const struct usb_device_id       products [] = {
 584 {
 585         USB_DEVICE(0x0525, 0x1080),     // NetChip ref design
 586         .driver_info =  (unsigned long) &net1080_info,
 587 }, {
 588         USB_DEVICE(0x06D0, 0x0622),     // Laplink Gold
 589         .driver_info =  (unsigned long) &net1080_info,
 590 },
 591         { },            // END
 592 };
 593 MODULE_DEVICE_TABLE(usb, products);
 594
 595 static struct usb_driver net1080_driver = {
 596         .name =         "net1080",
 597         .id_table =     products,
 598         .probe =        usbnet_probe,
 599         .disconnect =   usbnet_disconnect,
 600         .suspend =      usbnet_suspend,
 601         .resume =       usbnet_resume,
 602 };
 603
 604 static int __init net1080_init(void)
 605 {
 606         return usb_register(&net1080_driver);
 607 }
 608 module_init(net1080_init);
 609
 610 static void __exit net1080_exit(void)
 611 {
 612         usb_deregister(&net1080_driver);
 613 }
 614 module_exit(net1080_exit);
 615
 616 MODULE_AUTHOR("David Brownell");
 617 MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
 618 MODULE_LICENSE("GPL");