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