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                 return;
 160
 161         netdev_dbg(dev->net, "registers:\n");
 162         for (reg = 0; reg < 0x20; reg++) {
 163                 int retval;
 164
 165                 // reading some registers is trouble
 166                 if (reg >= 0x08 && reg <= 0xf)
 167                         continue;
 168                 if (reg >= 0x12 && reg <= 0x1e)
 169                         continue;
 170
 171                 retval = nc_register_read(dev, reg, vp);
 172                 if (retval < 0)
 173                         netdev_dbg(dev->net, "reg [0x%x] ==> error %d\n",
 174                                    reg, retval);
 175                 else
 176                         netdev_dbg(dev->net, "reg [0x%x] = 0x%x\n", reg, *vp);
 177         }
 178         kfree(vp);
 179 }
 180 #endif
 181
 182
 183 /*-------------------------------------------------------------------------*/
 184
 185 /*
 186  * Control register
 187  */
 188
 189 #define USBCTL_WRITABLE_MASK    0x1f0f
 190 // bits 15-13 reserved, r/o
 191 #define USBCTL_ENABLE_LANG      (1 << 12)
 192 #define USBCTL_ENABLE_MFGR      (1 << 11)
 193 #define USBCTL_ENABLE_PROD      (1 << 10)
 194 #define USBCTL_ENABLE_SERIAL    (1 << 9)
 195 #define USBCTL_ENABLE_DEFAULTS  (1 << 8)
 196 // bits 7-4 reserved, r/o
 197 #define USBCTL_FLUSH_OTHER      (1 << 3)
 198 #define USBCTL_FLUSH_THIS       (1 << 2)
 199 #define USBCTL_DISCONN_OTHER    (1 << 1)
 200 #define USBCTL_DISCONN_THIS     (1 << 0)
 201
 202 static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
 203 {
 204         netif_dbg(dev, link, dev->net,
 205                   "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s; this%s%s; other%s%s; r/o 0x%x\n",
 206                   dev->udev->bus->bus_name, dev->udev->devpath,
 207                   usbctl,
 208                   (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
 209                   (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
 210                   (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
 211                   (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
 212                   (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
 213
 214                   (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
 215                   (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
 216
 217                   (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
 218                   (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
 219
 220                   usbctl & ~USBCTL_WRITABLE_MASK);
 221 }
 222
 223 /*-------------------------------------------------------------------------*/
 224
 225 /*
 226  * Status register
 227  */
 228
 229 #define STATUS_PORT_A           (1 << 15)
 230
 231 #define STATUS_CONN_OTHER       (1 << 14)
 232 #define STATUS_SUSPEND_OTHER    (1 << 13)
 233 #define STATUS_MAILBOX_OTHER    (1 << 12)
 234 #define STATUS_PACKETS_OTHER(n) (((n) >> 8) & 0x03)
 235
 236 #define STATUS_CONN_THIS        (1 << 6)
 237 #define STATUS_SUSPEND_THIS     (1 << 5)
 238 #define STATUS_MAILBOX_THIS     (1 << 4)
 239 #define STATUS_PACKETS_THIS(n)  (((n) >> 0) & 0x03)
 240
 241 #define STATUS_UNSPEC_MASK      0x0c8c
 242 #define STATUS_NOISE_MASK       ((u16)~(0x0303|STATUS_UNSPEC_MASK))
 243
 244
 245 static inline void nc_dump_status(struct usbnet *dev, u16 status)
 246 {
 247         netif_dbg(dev, link, dev->net,
 248                   "net1080 %s-%s status 0x%x: this (%c) PKT=%d%s%s%s; other PKT=%d%s%s%s; unspec 0x%x\n",
 249                   dev->udev->bus->bus_name, dev->udev->devpath,
 250                   status,
 251
 252                   // XXX the packet counts don't seem right
 253                   // (1 at reset, not 0); maybe UNSPEC too
 254
 255                   (status & STATUS_PORT_A) ? 'A' : 'B',
 256                   STATUS_PACKETS_THIS(status),
 257                   (status & STATUS_CONN_THIS) ? " CON" : "",
 258                   (status & STATUS_SUSPEND_THIS) ? " SUS" : "",
 259                   (status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
 260
 261                   STATUS_PACKETS_OTHER(status),
 262                   (status & STATUS_CONN_OTHER) ? " CON" : "",
 263                   (status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
 264                   (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
 265
 266                   status & STATUS_UNSPEC_MASK);
 267 }
 268
 269 /*-------------------------------------------------------------------------*/
 270
 271 /*
 272  * TTL register
 273  */
 274
 275 #define TTL_THIS(ttl)   (0x00ff & ttl)
 276 #define TTL_OTHER(ttl)  (0x00ff & (ttl >> 8))
 277 #define MK_TTL(this,other)      ((u16)(((other)<<8)|(0x00ff&(this))))
 278
 279 static inline void nc_dump_ttl(struct usbnet *dev, u16 ttl)
 280 {
 281         netif_dbg(dev, link, dev->net, "net1080 %s-%s ttl 0x%x this = %d, other = %d\n",
 282                   dev->udev->bus->bus_name, dev->udev->devpath,
 283                   ttl, TTL_THIS(ttl), TTL_OTHER(ttl));
 284 }
 285
 286 /*-------------------------------------------------------------------------*/
 287
 288 static int net1080_reset(struct usbnet *dev)
 289 {
 290         u16             usbctl, status, ttl;
 291         u16             *vp = kmalloc(sizeof (u16), GFP_KERNEL);
 292         int             retval;
 293
 294         if (!vp)
 295                 return -ENOMEM;
 296
 297         // nc_dump_registers(dev);
 298
 299         if ((retval = nc_register_read(dev, REG_STATUS, vp)) < 0) {
 300                 netdev_dbg(dev->net, "can't read %s-%s status: %d\n",
 301                            dev->udev->bus->bus_name, dev->udev->devpath, retval);
 302                 goto done;
 303         }
 304         status = *vp;
 305         nc_dump_status(dev, status);
 306
 307         if ((retval = nc_register_read(dev, REG_USBCTL, vp)) < 0) {
 308                 netdev_dbg(dev->net, "can't read USBCTL, %d\n", retval);
 309                 goto done;
 310         }
 311         usbctl = *vp;
 312         nc_dump_usbctl(dev, usbctl);
 313
 314         nc_register_write(dev, REG_USBCTL,
 315                         USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
 316
 317         if ((retval = nc_register_read(dev, REG_TTL, vp)) < 0) {
 318                 netdev_dbg(dev->net, "can't read TTL, %d\n", retval);
 319                 goto done;
 320         }
 321         ttl = *vp;
 322         // nc_dump_ttl(dev, ttl);
 323
 324         nc_register_write(dev, REG_TTL,
 325                         MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
 326         netdev_dbg(dev->net, "assigned TTL, %d ms\n", NC_READ_TTL_MS);
 327
 328         netif_info(dev, link, dev->net, "port %c, peer %sconnected\n",
 329                    (status & STATUS_PORT_A) ? 'A' : 'B',
 330                    (status & STATUS_CONN_OTHER) ? "" : "dis");
 331         retval = 0;
 332
 333 done:
 334         kfree(vp);
 335         return retval;
 336 }
 337
 338 static int net1080_check_connect(struct usbnet *dev)
 339 {
 340         int                     retval;
 341         u16                     status;
 342         u16                     *vp = kmalloc(sizeof (u16), GFP_KERNEL);
 343
 344         if (!vp)
 345                 return -ENOMEM;
 346         retval = nc_register_read(dev, REG_STATUS, vp);
 347         status = *vp;
 348         kfree(vp);
 349         if (retval != 0) {
 350                 netdev_dbg(dev->net, "net1080_check_conn read - %d\n", retval);
 351                 return retval;
 352         }
 353         if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
 354                 return -ENOLINK;
 355         return 0;
 356 }
 357
 358 static void nc_flush_complete(struct urb *urb)
 359 {
 360         kfree(urb->context);
 361         usb_free_urb(urb);
 362 }
 363
 364 static void nc_ensure_sync(struct usbnet *dev)
 365 {
 366         dev->frame_errors++;
 367         if (dev->frame_errors > 5) {
 368                 struct urb              *urb;
 369                 struct usb_ctrlrequest  *req;
 370                 int                     status;
 371
 372                 /* Send a flush */
 373                 urb = usb_alloc_urb(0, GFP_ATOMIC);
 374                 if (!urb)
 375                         return;
 376
 377                 req = kmalloc(sizeof *req, GFP_ATOMIC);
 378                 if (!req) {
 379                         usb_free_urb(urb);
 380                         return;
 381                 }
 382
 383                 req->bRequestType = USB_DIR_OUT
 384                         | USB_TYPE_VENDOR
 385                         | USB_RECIP_DEVICE;
 386                 req->bRequest = REQUEST_REGISTER;
 387                 req->wValue = cpu_to_le16(USBCTL_FLUSH_THIS
 388                                 | USBCTL_FLUSH_OTHER);
 389                 req->wIndex = cpu_to_le16(REG_USBCTL);
 390                 req->wLength = cpu_to_le16(0);
 391
 392                 /* queue an async control request, we don't need
 393                  * to do anything when it finishes except clean up.
 394                  */
 395                 usb_fill_control_urb(urb, dev->udev,
 396                         usb_sndctrlpipe(dev->udev, 0),
 397                         (unsigned char *) req,
 398                         NULL, 0,
 399                         nc_flush_complete, req);
 400                 status = usb_submit_urb(urb, GFP_ATOMIC);
 401                 if (status) {
 402                         kfree(req);
 403                         usb_free_urb(urb);
 404                         return;
 405                 }
 406
 407                 netif_dbg(dev, rx_err, dev->net,
 408                           "flush net1080; too many framing errors\n");
 409                 dev->frame_errors = 0;
 410         }
 411 }
 412
 413 static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 414 {
 415         struct nc_header        *header;
 416         struct nc_trailer       *trailer;
 417         u16                     hdr_len, packet_len;
 418
 419         if (!(skb->len & 0x01)) {
 420                 netdev_dbg(dev->net, "rx framesize %d range %d..%d mtu %d\n",
 421                            skb->len, dev->net->hard_header_len, dev->hard_mtu,
 422                            dev->net->mtu);
 423                 dev->net->stats.rx_frame_errors++;
 424                 nc_ensure_sync(dev);
 425                 return 0;
 426         }
 427
 428         header = (struct nc_header *) skb->data;
 429         hdr_len = le16_to_cpup(&header->hdr_len);
 430         packet_len = le16_to_cpup(&header->packet_len);
 431         if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
 432                 dev->net->stats.rx_frame_errors++;
 433                 netdev_dbg(dev->net, "packet too big, %d\n", packet_len);
 434                 nc_ensure_sync(dev);
 435                 return 0;
 436         } else if (hdr_len < MIN_HEADER) {
 437                 dev->net->stats.rx_frame_errors++;
 438                 netdev_dbg(dev->net, "header too short, %d\n", hdr_len);
 439                 nc_ensure_sync(dev);
 440                 return 0;
 441         } else if (hdr_len > MIN_HEADER) {
 442                 // out of band data for us?
 443                 netdev_dbg(dev->net, "header OOB, %d bytes\n", hdr_len - MIN_HEADER);
 444                 nc_ensure_sync(dev);
 445                 // switch (vendor/product ids) { ... }
 446         }
 447         skb_pull(skb, hdr_len);
 448
 449         trailer = (struct nc_trailer *)
 450                 (skb->data + skb->len - sizeof *trailer);
 451         skb_trim(skb, skb->len - sizeof *trailer);
 452
 453         if ((packet_len & 0x01) == 0) {
 454                 if (skb->data [packet_len] != PAD_BYTE) {
 455                         dev->net->stats.rx_frame_errors++;
 456                         netdev_dbg(dev->net, "bad pad\n");
 457                         return 0;
 458                 }
 459                 skb_trim(skb, skb->len - 1);
 460         }
 461         if (skb->len != packet_len) {
 462                 dev->net->stats.rx_frame_errors++;
 463                 netdev_dbg(dev->net, "bad packet len %d (expected %d)\n",
 464                            skb->len, packet_len);
 465                 nc_ensure_sync(dev);
 466                 return 0;
 467         }
 468         if (header->packet_id != get_unaligned(&trailer->packet_id)) {
 469                 dev->net->stats.rx_fifo_errors++;
 470                 netdev_dbg(dev->net, "(2+ dropped) rx packet_id mismatch 0x%x 0x%x\n",
 471                            le16_to_cpu(header->packet_id),
 472                            le16_to_cpu(trailer->packet_id));
 473                 return 0;
 474         }
 475 #if 0
 476         netdev_dbg(dev->net, "frame <rx h %d p %d id %d\n", header->hdr_len,
 477                    header->packet_len, header->packet_id);
 478 #endif
 479         dev->frame_errors = 0;
 480         return 1;
 481 }
 482
 483 static struct sk_buff *
 484 net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 485 {
 486         struct sk_buff          *skb2;
 487         struct nc_header        *header = NULL;
 488         struct nc_trailer       *trailer = NULL;
 489         int                     padlen = sizeof (struct nc_trailer);
 490         int                     len = skb->len;
 491
 492         if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
 493                 padlen++;
 494         if (!skb_cloned(skb)) {
 495                 int     headroom = skb_headroom(skb);
 496                 int     tailroom = skb_tailroom(skb);
 497
 498                 if (padlen <= tailroom &&
 499                     sizeof(struct nc_header) <= headroom)
 500                         /* There's enough head and tail room */
 501                         goto encapsulate;
 502
 503                 if ((sizeof (struct nc_header) + padlen) <
 504                                 (headroom + tailroom)) {
 505                         /* There's enough total room, so just readjust */
 506                         skb->data = memmove(skb->head
 507                                                 + sizeof (struct nc_header),
 508                                             skb->data, skb->len);
 509                         skb_set_tail_pointer(skb, len);
 510                         goto encapsulate;
 511                 }
 512         }
 513
 514         /* Create a new skb to use with the correct size */
 515         skb2 = skb_copy_expand(skb,
 516                                 sizeof (struct nc_header),
 517                                 padlen,
 518                                 flags);
 519         dev_kfree_skb_any(skb);
 520         if (!skb2)
 521                 return skb2;
 522         skb = skb2;
 523
 524 encapsulate:
 525         /* header first */
 526         header = (struct nc_header *) skb_push(skb, sizeof *header);
 527         header->hdr_len = cpu_to_le16(sizeof (*header));
 528         header->packet_len = cpu_to_le16(len);
 529         header->packet_id = cpu_to_le16((u16)dev->xid++);
 530
 531         /* maybe pad; then trailer */
 532         if (!((skb->len + sizeof *trailer) & 0x01))
 533                 *skb_put(skb, 1) = PAD_BYTE;
 534         trailer = (struct nc_trailer *) skb_put(skb, sizeof *trailer);
 535         put_unaligned(header->packet_id, &trailer->packet_id);
 536 #if 0
 537         netdev_dbg(dev->net, "frame >tx h %d p %d id %d\n",
 538                    header->hdr_len, header->packet_len,
 539                    header->packet_id);
 540 #endif
 541         return skb;
 542 }
 543
 544 static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
 545 {
 546         unsigned        extra = sizeof (struct nc_header)
 547                                 + 1
 548                                 + sizeof (struct nc_trailer);
 549
 550         dev->net->hard_header_len += extra;
 551         dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
 552         dev->hard_mtu = NC_MAX_PACKET;
 553         return usbnet_get_endpoints (dev, intf);
 554 }
 555
 556 static const struct driver_info net1080_info = {
 557         .description =  "NetChip TurboCONNECT",
 558         .flags =        FLAG_POINTTOPOINT | FLAG_FRAMING_NC,
 559         .bind =         net1080_bind,
 560         .reset =        net1080_reset,
 561         .check_connect = net1080_check_connect,
 562         .rx_fixup =     net1080_rx_fixup,
 563         .tx_fixup =     net1080_tx_fixup,
 564 };
 565
 566 static const struct usb_device_id       products [] = {
 567 {
 568         USB_DEVICE(0x0525, 0x1080),     // NetChip ref design
 569         .driver_info =  (unsigned long) &net1080_info,
 570 }, {
 571         USB_DEVICE(0x06D0, 0x0622),     // Laplink Gold
 572         .driver_info =  (unsigned long) &net1080_info,
 573 },
 574         { },            // END
 575 };
 576 MODULE_DEVICE_TABLE(usb, products);
 577
 578 static struct usb_driver net1080_driver = {
 579         .name =         "net1080",
 580         .id_table =     products,
 581         .probe =        usbnet_probe,
 582         .disconnect =   usbnet_disconnect,
 583         .suspend =      usbnet_suspend,
 584         .resume =       usbnet_resume,
 585         .disable_hub_initiated_lpm = 1,
 586 };
 587
 588 module_usb_driver(net1080_driver);
 589
 590 MODULE_AUTHOR("David Brownell");
 591 MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
 592 MODULE_LICENSE("GPL");