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