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