drivers/usb/storage/datafab.c

   1 /* Driver for Datafab USB Compact Flash reader
   2  *
   3  * $Id: datafab.c,v 1.7 2002/02/25 00:40:13 mdharm Exp $
   4  *
   5  * datafab driver v0.1:
   6  *
   7  * First release
   8  *
   9  * Current development and maintenance by:
  10  *   (c) 2000 Jimmie Mayfield (mayfield+datafab@sackheads.org)
  11  *
  12  *   Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
  13  *   which I used as a template for this driver.
  14  *
  15  *   Some bugfixes and scatter-gather code by Gregory P. Smith
  16  *   (greg-usb@electricrain.com)
  17  *
  18  *   Fix for media change by Joerg Schneider (js@joergschneider.com)
  19  *
  20  * Other contributors:
  21  *   (c) 2002 Alan Stern <stern@rowland.org>
  22  *
  23  * This program is free software; you can redistribute it and/or modify it
  24  * under the terms of the GNU General Public License as published by the
  25  * Free Software Foundation; either version 2, or (at your option) any
  26  * later version.
  27  *
  28  * This program is distributed in the hope that it will be useful, but
  29  * WITHOUT ANY WARRANTY; without even the implied warranty of
  30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  31  * General Public License for more details.
  32  *
  33  * You should have received a copy of the GNU General Public License along
  34  * with this program; if not, write to the Free Software Foundation, Inc.,
  35  * 675 Mass Ave, Cambridge, MA 02139, USA.
  36  */
  37
  38 /*
  39  * This driver attempts to support USB CompactFlash reader/writer devices
  40  * based on Datafab USB-to-ATA chips.  It was specifically developed for the
  41  * Datafab MDCFE-B USB CompactFlash reader but has since been found to work
  42  * with a variety of Datafab-based devices from a number of manufacturers.
  43  * I've received a report of this driver working with a Datafab-based
  44  * SmartMedia device though please be aware that I'm personally unable to
  45  * test SmartMedia support.
  46  *
  47  * This driver supports reading and writing.  If you're truly paranoid,
  48  * however, you can force the driver into a write-protected state by setting
  49  * the WP enable bits in datafab_handle_mode_sense().  See the comments
  50  * in that routine.
  51  */
  52
  53 #include <linux/errno.h>
  54 #include <linux/slab.h>
  55
  56 #include <scsi/scsi.h>
  57 #include <scsi/scsi_cmnd.h>
  58
  59 #include "usb.h"
  60 #include "transport.h"
  61 #include "protocol.h"
  62 #include "debug.h"
  63 #include "datafab.h"
  64
  65 static int datafab_determine_lun(struct us_data *us,
  66                                  struct datafab_info *info);
  67
  68
  69 static inline int
  70 datafab_bulk_read(struct us_data *us, unsigned char *data, unsigned int len) {
  71         if (len == 0)
  72                 return USB_STOR_XFER_GOOD;
  73
  74         US_DEBUGP("datafab_bulk_read:  len = %d\n", len);
  75         return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
  76                         data, len, NULL);
  77 }
  78
  79
  80 static inline int
  81 datafab_bulk_write(struct us_data *us, unsigned char *data, unsigned int len) {
  82         if (len == 0)
  83                 return USB_STOR_XFER_GOOD;
  84
  85         US_DEBUGP("datafab_bulk_write:  len = %d\n", len);
  86         return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
  87                         data, len, NULL);
  88 }
  89
  90
  91 static int datafab_read_data(struct us_data *us,
  92                              struct datafab_info *info,
  93                              u32 sector,
  94                              u32 sectors)
  95 {
  96         unsigned char *command = us->iobuf;
  97         unsigned char *buffer;
  98         unsigned char  thistime;
  99         unsigned int totallen, alloclen;
 100         int len, result;
 101         unsigned int sg_offset = 0;
 102         struct scatterlist *sg = NULL;
 103
 104         // we're working in LBA mode.  according to the ATA spec,
 105         // we can support up to 28-bit addressing.  I don't know if Datafab
 106         // supports beyond 24-bit addressing.  It's kind of hard to test
 107         // since it requires > 8GB CF card.
 108         //
 109         if (sectors > 0x0FFFFFFF)
 110                 return USB_STOR_TRANSPORT_ERROR;
 111
 112         if (info->lun == -1) {
 113                 result = datafab_determine_lun(us, info);
 114                 if (result != USB_STOR_TRANSPORT_GOOD)
 115                         return result;
 116         }
 117
 118         totallen = sectors * info->ssize;
 119
 120         // Since we don't read more than 64 KB at a time, we have to create
 121         // a bounce buffer and move the data a piece at a time between the
 122         // bounce buffer and the actual transfer buffer.
 123
 124         alloclen = min(totallen, 65536u);
 125         buffer = kmalloc(alloclen, GFP_NOIO);
 126         if (buffer == NULL)
 127                 return USB_STOR_TRANSPORT_ERROR;
 128
 129         do {
 130                 // loop, never allocate or transfer more than 64k at once
 131                 // (min(128k, 255*info->ssize) is the real limit)
 132
 133                 len = min(totallen, alloclen);
 134                 thistime = (len / info->ssize) & 0xff;
 135
 136                 command[0] = 0;
 137                 command[1] = thistime;
 138                 command[2] = sector & 0xFF;
 139                 command[3] = (sector >> 8) & 0xFF;
 140                 command[4] = (sector >> 16) & 0xFF;
 141
 142                 command[5] = 0xE0 + (info->lun << 4);
 143                 command[5] |= (sector >> 24) & 0x0F;
 144                 command[6] = 0x20;
 145                 command[7] = 0x01;
 146
 147                 // send the read command
 148                 result = datafab_bulk_write(us, command, 8);
 149                 if (result != USB_STOR_XFER_GOOD)
 150                         goto leave;
 151
 152                 // read the result
 153                 result = datafab_bulk_read(us, buffer, len);
 154                 if (result != USB_STOR_XFER_GOOD)
 155                         goto leave;
 156
 157                 // Store the data in the transfer buffer
 158                 usb_stor_access_xfer_buf(buffer, len, us->srb,
 159                                  &sg, &sg_offset, TO_XFER_BUF);
 160
 161                 sector += thistime;
 162                 totallen -= len;
 163         } while (totallen > 0);
 164
 165         kfree(buffer);
 166         return USB_STOR_TRANSPORT_GOOD;
 167
 168  leave:
 169         kfree(buffer);
 170         return USB_STOR_TRANSPORT_ERROR;
 171 }
 172
 173
 174 static int datafab_write_data(struct us_data *us,
 175                               struct datafab_info *info,
 176                               u32 sector,
 177                               u32 sectors)
 178 {
 179         unsigned char *command = us->iobuf;
 180         unsigned char *reply = us->iobuf;
 181         unsigned char *buffer;
 182         unsigned char thistime;
 183         unsigned int totallen, alloclen;
 184         int len, result;
 185         unsigned int sg_offset = 0;
 186         struct scatterlist *sg = NULL;
 187
 188         // we're working in LBA mode.  according to the ATA spec,
 189         // we can support up to 28-bit addressing.  I don't know if Datafab
 190         // supports beyond 24-bit addressing.  It's kind of hard to test
 191         // since it requires > 8GB CF card.
 192         //
 193         if (sectors > 0x0FFFFFFF)
 194                 return USB_STOR_TRANSPORT_ERROR;
 195
 196         if (info->lun == -1) {
 197                 result = datafab_determine_lun(us, info);
 198                 if (result != USB_STOR_TRANSPORT_GOOD)
 199                         return result;
 200         }
 201
 202         totallen = sectors * info->ssize;
 203
 204         // Since we don't write more than 64 KB at a time, we have to create
 205         // a bounce buffer and move the data a piece at a time between the
 206         // bounce buffer and the actual transfer buffer.
 207
 208         alloclen = min(totallen, 65536u);
 209         buffer = kmalloc(alloclen, GFP_NOIO);
 210         if (buffer == NULL)
 211                 return USB_STOR_TRANSPORT_ERROR;
 212
 213         do {
 214                 // loop, never allocate or transfer more than 64k at once
 215                 // (min(128k, 255*info->ssize) is the real limit)
 216
 217                 len = min(totallen, alloclen);
 218                 thistime = (len / info->ssize) & 0xff;
 219
 220                 // Get the data from the transfer buffer
 221                 usb_stor_access_xfer_buf(buffer, len, us->srb,
 222                                 &sg, &sg_offset, FROM_XFER_BUF);
 223
 224                 command[0] = 0;
 225                 command[1] = thistime;
 226                 command[2] = sector & 0xFF;
 227                 command[3] = (sector >> 8) & 0xFF;
 228                 command[4] = (sector >> 16) & 0xFF;
 229
 230                 command[5] = 0xE0 + (info->lun << 4);
 231                 command[5] |= (sector >> 24) & 0x0F;
 232                 command[6] = 0x30;
 233                 command[7] = 0x02;
 234
 235                 // send the command
 236                 result = datafab_bulk_write(us, command, 8);
 237                 if (result != USB_STOR_XFER_GOOD)
 238                         goto leave;
 239
 240                 // send the data
 241                 result = datafab_bulk_write(us, buffer, len);
 242                 if (result != USB_STOR_XFER_GOOD)
 243                         goto leave;
 244
 245                 // read the result
 246                 result = datafab_bulk_read(us, reply, 2);
 247                 if (result != USB_STOR_XFER_GOOD)
 248                         goto leave;
 249
 250                 if (reply[0] != 0x50 && reply[1] != 0) {
 251                         US_DEBUGP("datafab_write_data:  Gah! "
 252                                   "write return code: %02x %02x\n",
 253                                   reply[0], reply[1]);
 254                         result = USB_STOR_TRANSPORT_ERROR;
 255                         goto leave;
 256                 }
 257
 258                 sector += thistime;
 259                 totallen -= len;
 260         } while (totallen > 0);
 261
 262         kfree(buffer);
 263         return USB_STOR_TRANSPORT_GOOD;
 264
 265  leave:
 266         kfree(buffer);
 267         return USB_STOR_TRANSPORT_ERROR;
 268 }
 269
 270
 271 static int datafab_determine_lun(struct us_data *us,
 272                                  struct datafab_info *info)
 273 {
 274         // Dual-slot readers can be thought of as dual-LUN devices.
 275         // We need to determine which card slot is being used.
 276         // We'll send an IDENTIFY DEVICE command and see which LUN responds...
 277         //
 278         // There might be a better way of doing this?
 279
 280         static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
 281         unsigned char *command = us->iobuf;
 282         unsigned char *buf;
 283         int count = 0, rc;
 284
 285         if (!us || !info)
 286                 return USB_STOR_TRANSPORT_ERROR;
 287
 288         memcpy(command, scommand, 8);
 289         buf = kmalloc(512, GFP_NOIO);
 290         if (!buf)
 291                 return USB_STOR_TRANSPORT_ERROR;
 292
 293         US_DEBUGP("datafab_determine_lun:  locating...\n");
 294
 295         // we'll try 3 times before giving up...
 296         //
 297         while (count++ < 3) {
 298                 command[5] = 0xa0;
 299
 300                 rc = datafab_bulk_write(us, command, 8);
 301                 if (rc != USB_STOR_XFER_GOOD) {
 302                         rc = USB_STOR_TRANSPORT_ERROR;
 303                         goto leave;
 304                 }
 305
 306                 rc = datafab_bulk_read(us, buf, 512);
 307                 if (rc == USB_STOR_XFER_GOOD) {
 308                         info->lun = 0;
 309                         rc = USB_STOR_TRANSPORT_GOOD;
 310                         goto leave;
 311                 }
 312
 313                 command[5] = 0xb0;
 314
 315                 rc = datafab_bulk_write(us, command, 8);
 316                 if (rc != USB_STOR_XFER_GOOD) {
 317                         rc = USB_STOR_TRANSPORT_ERROR;
 318                         goto leave;
 319                 }
 320
 321                 rc = datafab_bulk_read(us, buf, 512);
 322                 if (rc == USB_STOR_XFER_GOOD) {
 323                         info->lun = 1;
 324                         rc = USB_STOR_TRANSPORT_GOOD;
 325                         goto leave;
 326                 }
 327
 328                 msleep(20);
 329         }
 330
 331         rc = USB_STOR_TRANSPORT_ERROR;
 332
 333  leave:
 334         kfree(buf);
 335         return rc;
 336 }
 337
 338 static int datafab_id_device(struct us_data *us,
 339                              struct datafab_info *info)
 340 {
 341         // this is a variation of the ATA "IDENTIFY DEVICE" command...according
 342         // to the ATA spec, 'Sector Count' isn't used but the Windows driver
 343         // sets this bit so we do too...
 344         //
 345         static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
 346         unsigned char *command = us->iobuf;
 347         unsigned char *reply;
 348         int rc;
 349
 350         if (!us || !info)
 351                 return USB_STOR_TRANSPORT_ERROR;
 352
 353         if (info->lun == -1) {
 354                 rc = datafab_determine_lun(us, info);
 355                 if (rc != USB_STOR_TRANSPORT_GOOD)
 356                         return rc;
 357         }
 358
 359         memcpy(command, scommand, 8);
 360         reply = kmalloc(512, GFP_NOIO);
 361         if (!reply)
 362                 return USB_STOR_TRANSPORT_ERROR;
 363
 364         command[5] += (info->lun << 4);
 365
 366         rc = datafab_bulk_write(us, command, 8);
 367         if (rc != USB_STOR_XFER_GOOD) {
 368                 rc = USB_STOR_TRANSPORT_ERROR;
 369                 goto leave;
 370         }
 371
 372         // we'll go ahead and extract the media capacity while we're here...
 373         //
 374         rc = datafab_bulk_read(us, reply, 512);
 375         if (rc == USB_STOR_XFER_GOOD) {
 376                 // capacity is at word offset 57-58
 377                 //
 378                 info->sectors = ((u32)(reply[117]) << 24) |
 379                                 ((u32)(reply[116]) << 16) |
 380                                 ((u32)(reply[115]) <<  8) |
 381                                 ((u32)(reply[114])      );
 382                 rc = USB_STOR_TRANSPORT_GOOD;
 383                 goto leave;
 384         }
 385
 386         rc = USB_STOR_TRANSPORT_ERROR;
 387
 388  leave:
 389         kfree(reply);
 390         return rc;
 391 }
 392
 393
 394 static int datafab_handle_mode_sense(struct us_data *us,
 395                                      struct scsi_cmnd * srb,
 396                                      int sense_6)
 397 {
 398         static unsigned char rw_err_page[12] = {
 399                 0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
 400         };
 401         static unsigned char cache_page[12] = {
 402                 0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
 403         };
 404         static unsigned char rbac_page[12] = {
 405                 0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
 406         };
 407         static unsigned char timer_page[8] = {
 408                 0x1C, 0x6, 0, 0, 0, 0
 409         };
 410         unsigned char pc, page_code;
 411         unsigned int i = 0;
 412         struct datafab_info *info = (struct datafab_info *) (us->extra);
 413         unsigned char *ptr = us->iobuf;
 414
 415         // most of this stuff is just a hack to get things working.  the
 416         // datafab reader doesn't present a SCSI interface so we
 417         // fudge the SCSI commands...
 418         //
 419
 420         pc = srb->cmnd[2] >> 6;
 421         page_code = srb->cmnd[2] & 0x3F;
 422
 423         switch (pc) {
 424            case 0x0:
 425                 US_DEBUGP("datafab_handle_mode_sense:  Current values\n");
 426                 break;
 427            case 0x1:
 428                 US_DEBUGP("datafab_handle_mode_sense:  Changeable values\n");
 429                 break;
 430            case 0x2:
 431                 US_DEBUGP("datafab_handle_mode_sense:  Default values\n");
 432                 break;
 433            case 0x3:
 434                 US_DEBUGP("datafab_handle_mode_sense:  Saves values\n");
 435                 break;
 436         }
 437
 438         memset(ptr, 0, 8);
 439         if (sense_6) {
 440                 ptr[2] = 0x00;          // WP enable: 0x80
 441                 i = 4;
 442         } else {
 443                 ptr[3] = 0x00;          // WP enable: 0x80
 444                 i = 8;
 445         }
 446
 447         switch (page_code) {
 448            default:
 449                 // vendor-specific mode
 450                 info->sense_key = 0x05;
 451                 info->sense_asc = 0x24;
 452                 info->sense_ascq = 0x00;
 453                 return USB_STOR_TRANSPORT_FAILED;
 454
 455            case 0x1:
 456                 memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
 457                 i += sizeof(rw_err_page);
 458                 break;
 459
 460            case 0x8:
 461                 memcpy(ptr + i, cache_page, sizeof(cache_page));
 462                 i += sizeof(cache_page);
 463                 break;
 464
 465            case 0x1B:
 466                 memcpy(ptr + i, rbac_page, sizeof(rbac_page));
 467                 i += sizeof(rbac_page);
 468                 break;
 469
 470            case 0x1C:
 471                 memcpy(ptr + i, timer_page, sizeof(timer_page));
 472                 i += sizeof(timer_page);
 473                 break;
 474
 475            case 0x3F:           // retrieve all pages
 476                 memcpy(ptr + i, timer_page, sizeof(timer_page));
 477                 i += sizeof(timer_page);
 478                 memcpy(ptr + i, rbac_page, sizeof(rbac_page));
 479                 i += sizeof(rbac_page);
 480                 memcpy(ptr + i, cache_page, sizeof(cache_page));
 481                 i += sizeof(cache_page);
 482                 memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
 483                 i += sizeof(rw_err_page);
 484                 break;
 485         }
 486
 487         if (sense_6)
 488                 ptr[0] = i - 1;
 489         else
 490                 ((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
 491         usb_stor_set_xfer_buf(ptr, i, srb);
 492
 493         return USB_STOR_TRANSPORT_GOOD;
 494 }
 495
 496 static void datafab_info_destructor(void *extra)
 497 {
 498         // this routine is a placeholder...
 499         // currently, we don't allocate any extra memory so we're okay
 500 }
 501
 502
 503 // Transport for the Datafab MDCFE-B
 504 //
 505 int datafab_transport(struct scsi_cmnd * srb, struct us_data *us)
 506 {
 507         struct datafab_info *info;
 508         int rc;
 509         unsigned long block, blocks;
 510         unsigned char *ptr = us->iobuf;
 511         static unsigned char inquiry_reply[8] = {
 512                 0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
 513         };
 514
 515         if (!us->extra) {
 516                 us->extra = kzalloc(sizeof(struct datafab_info), GFP_NOIO);
 517                 if (!us->extra) {
 518                         US_DEBUGP("datafab_transport:  Gah! "
 519                                   "Can't allocate storage for Datafab info struct!\n");
 520                         return USB_STOR_TRANSPORT_ERROR;
 521                 }
 522                 us->extra_destructor = datafab_info_destructor;
 523                 ((struct datafab_info *)us->extra)->lun = -1;
 524         }
 525
 526         info = (struct datafab_info *) (us->extra);
 527
 528         if (srb->cmnd[0] == INQUIRY) {
 529                 US_DEBUGP("datafab_transport:  INQUIRY.  Returning bogus response");
 530                 memcpy(ptr, inquiry_reply, sizeof(inquiry_reply));
 531                 fill_inquiry_response(us, ptr, 36);
 532                 return USB_STOR_TRANSPORT_GOOD;
 533         }
 534
 535         if (srb->cmnd[0] == READ_CAPACITY) {
 536                 info->ssize = 0x200;  // hard coded 512 byte sectors as per ATA spec
 537                 rc = datafab_id_device(us, info);
 538                 if (rc != USB_STOR_TRANSPORT_GOOD)
 539                         return rc;
 540
 541                 US_DEBUGP("datafab_transport:  READ_CAPACITY:  %ld sectors, %ld bytes per sector\n",
 542                           info->sectors, info->ssize);
 543
 544                 // build the reply
 545                 // we need the last sector, not the number of sectors
 546                 ((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
 547                 ((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
 548                 usb_stor_set_xfer_buf(ptr, 8, srb);
 549
 550                 return USB_STOR_TRANSPORT_GOOD;
 551         }
 552
 553         if (srb->cmnd[0] == MODE_SELECT_10) {
 554                 US_DEBUGP("datafab_transport:  Gah! MODE_SELECT_10.\n");
 555                 return USB_STOR_TRANSPORT_ERROR;
 556         }
 557
 558         // don't bother implementing READ_6 or WRITE_6.
 559         //
 560         if (srb->cmnd[0] == READ_10) {
 561                 block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 562                         ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
 563
 564                 blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
 565
 566                 US_DEBUGP("datafab_transport:  READ_10: read block 0x%04lx  count %ld\n", block, blocks);
 567                 return datafab_read_data(us, info, block, blocks);
 568         }
 569
 570         if (srb->cmnd[0] == READ_12) {
 571                 // we'll probably never see a READ_12 but we'll do it anyway...
 572                 //
 573                 block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 574                         ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
 575
 576                 blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
 577                          ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));
 578
 579                 US_DEBUGP("datafab_transport:  READ_12: read block 0x%04lx  count %ld\n", block, blocks);
 580                 return datafab_read_data(us, info, block, blocks);
 581         }
 582
 583         if (srb->cmnd[0] == WRITE_10) {
 584                 block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 585                         ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
 586
 587                 blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
 588
 589                 US_DEBUGP("datafab_transport:  WRITE_10: write block 0x%04lx  count %ld\n", block, blocks);
 590                 return datafab_write_data(us, info, block, blocks);
 591         }
 592
 593         if (srb->cmnd[0] == WRITE_12) {
 594                 // we'll probably never see a WRITE_12 but we'll do it anyway...
 595                 //
 596                 block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 597                         ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
 598
 599                 blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
 600                          ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));
 601
 602                 US_DEBUGP("datafab_transport:  WRITE_12: write block 0x%04lx  count %ld\n", block, blocks);
 603                 return datafab_write_data(us, info, block, blocks);
 604         }
 605
 606         if (srb->cmnd[0] == TEST_UNIT_READY) {
 607                 US_DEBUGP("datafab_transport:  TEST_UNIT_READY.\n");
 608                 return datafab_id_device(us, info);
 609         }
 610
 611         if (srb->cmnd[0] == REQUEST_SENSE) {
 612                 US_DEBUGP("datafab_transport:  REQUEST_SENSE.  Returning faked response\n");
 613
 614                 // this response is pretty bogus right now.  eventually if necessary
 615                 // we can set the correct sense data.  so far though it hasn't been
 616                 // necessary
 617                 //
 618                 memset(ptr, 0, 18);
 619                 ptr[0] = 0xF0;
 620                 ptr[2] = info->sense_key;
 621                 ptr[7] = 11;
 622                 ptr[12] = info->sense_asc;
 623                 ptr[13] = info->sense_ascq;
 624                 usb_stor_set_xfer_buf(ptr, 18, srb);
 625
 626                 return USB_STOR_TRANSPORT_GOOD;
 627         }
 628
 629         if (srb->cmnd[0] == MODE_SENSE) {
 630                 US_DEBUGP("datafab_transport:  MODE_SENSE_6 detected\n");
 631                 return datafab_handle_mode_sense(us, srb, 1);
 632         }
 633
 634         if (srb->cmnd[0] == MODE_SENSE_10) {
 635                 US_DEBUGP("datafab_transport:  MODE_SENSE_10 detected\n");
 636                 return datafab_handle_mode_sense(us, srb, 0);
 637         }
 638
 639         if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
 640                 // sure.  whatever.  not like we can stop the user from
 641                 // popping the media out of the device (no locking doors, etc)
 642                 //
 643                 return USB_STOR_TRANSPORT_GOOD;
 644         }
 645
 646         if (srb->cmnd[0] == START_STOP) {
 647                 /* this is used by sd.c'check_scsidisk_media_change to detect
 648                    media change */
 649                 US_DEBUGP("datafab_transport:  START_STOP.\n");
 650                 /* the first datafab_id_device after a media change returns
 651                    an error (determined experimentally) */
 652                 rc = datafab_id_device(us, info);
 653                 if (rc == USB_STOR_TRANSPORT_GOOD) {
 654                         info->sense_key = NO_SENSE;
 655                         srb->result = SUCCESS;
 656                 } else {
 657                         info->sense_key = UNIT_ATTENTION;
 658                         srb->result = SAM_STAT_CHECK_CONDITION;
 659                 }
 660                 return rc;
 661         }
 662
 663         US_DEBUGP("datafab_transport:  Gah! Unknown command: %d (0x%x)\n",
 664                   srb->cmnd[0], srb->cmnd[0]);
 665         info->sense_key = 0x05;
 666         info->sense_asc = 0x20;
 667         info->sense_ascq = 0x00;
 668         return USB_STOR_TRANSPORT_FAILED;
 669 }