linux/drivers/net/usb/net1080.c
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   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
  57struct 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
  70struct 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
 108static int
 109nc_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
 125static inline int
 126nc_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()
 132static void
 133nc_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
 144static inline void
 145nc_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
 152static 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
 204static 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
 249static 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
 287static 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
 297static 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
 344done:
 345        kfree(vp);
 346        return retval;
 347}
 348
 349static 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
 369static void nc_flush_complete(struct urb *urb)
 370{
 371        kfree(urb->context);
 372        usb_free_urb(urb);
 373}
 374
 375static 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
 424static 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->net->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->net->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->net->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->net->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->net->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->net->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
 496static struct sk_buff *
 497net1080_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
 537encapsulate:
 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
 557static 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
 569static 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
 579static 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};
 589MODULE_DEVICE_TABLE(usb, products);
 590
 591static 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
 600static int __init net1080_init(void)
 601{
 602        return usb_register(&net1080_driver);
 603}
 604module_init(net1080_init);
 605
 606static void __exit net1080_exit(void)
 607{
 608        usb_deregister(&net1080_driver);
 609}
 610module_exit(net1080_exit);
 611
 612MODULE_AUTHOR("David Brownell");
 613MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
 614MODULE_LICENSE("GPL");
 615