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