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