software/SCSI2SD/src/scsi.c

   1 //      Copyright (C) 2014 Michael McMaster <michael@codesrc.com>\r
   2 //\r
   3 //      This file is part of SCSI2SD.\r
   4 //\r
   5 //      SCSI2SD is free software: you can redistribute it and/or modify\r
   6 //      it under the terms of the GNU General Public License as published by\r
   7 //      the Free Software Foundation, either version 3 of the License, or\r
   8 //      (at your option) any later version.\r
   9 //\r
  10 //      SCSI2SD is distributed in the hope that it will be useful,\r
  11 //      but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  12 //      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  13 //      GNU General Public License for more details.\r
  14 //\r
  15 //      You should have received a copy of the GNU General Public License\r
  16 //      along with SCSI2SD.  If not, see <http://www.gnu.org/licenses/>.\r
  17 #pragma GCC push_options\r
  18 #pragma GCC optimize("-flto")\r
  19 \r
  20 #include "device.h"\r
  21 #include "scsi.h"\r
  22 #include "scsiPhy.h"\r
  23 #include "config.h"\r
  24 #include "bits.h"\r
  25 #include "diagnostic.h"\r
  26 #include "disk.h"\r
  27 #include "inquiry.h"\r
  28 #include "led.h"\r
  29 #include "mode.h"\r
  30 #include "disk.h"\r
  31 #include "time.h"\r
  32 #include "cdrom.h"\r
  33 #include "debug.h"\r
  34 \r
  35 #include <string.h>\r
  36 \r
  37 // Global SCSI device state.\r
  38 ScsiDevice scsiDev;\r
  39 \r
  40 static void enter_SelectionPhase(void);\r
  41 static void process_SelectionPhase(void);\r
  42 static void enter_BusFree(void);\r
  43 static void enter_MessageIn(uint8 message);\r
  44 static void enter_Status(uint8 status);\r
  45 static void enter_DataIn(int len);\r
  46 static void process_DataIn(void);\r
  47 static void process_DataOut(void);\r
  48 static void process_Command(void);\r
  49 \r
  50 static void doReserveRelease(void);\r
  51 \r
  52 static void enter_BusFree()\r
  53 {\r
  54         // This delay probably isn't needed for most SCSI hosts, but it won't\r
  55         // hurt either. It's possible some of the samplers needed this delay.\r
  56         if (scsiDev.compatMode < COMPAT_SCSI2)\r
  57         {\r
  58                 CyDelayUs(2);\r
  59         }\r
  60 \r
  61         if (scsiDev.status != GOOD && isDebugEnabled())\r
  62         {\r
  63                 // We want to capture debug information for failure cases.\r
  64                 CyDelay(64);\r
  65         }\r
  66 \r
  67         SCSI_ClearPin(SCSI_Out_BSY);\r
  68         // We now have a Bus Clear Delay of 800ns to release remaining signals.\r
  69         SCSI_CTL_PHASE_Write(0);\r
  70 \r
  71         // Wait for the initiator to cease driving signals\r
  72         // Bus settle delay + bus clear delay = 1200ns\r
  73         CyDelayUs(2);\r
  74 \r
  75         ledOff();\r
  76         scsiDev.phase = BUS_FREE;\r
  77 }\r
  78 \r
  79 static void enter_MessageIn(uint8 message)\r
  80 {\r
  81         scsiDev.msgIn = message;\r
  82         scsiDev.phase = MESSAGE_IN;\r
  83 }\r
  84 \r
  85 void process_MessageIn()\r
  86 {\r
  87         scsiEnterPhase(MESSAGE_IN);\r
  88         scsiWriteByte(scsiDev.msgIn);\r
  89 \r
  90         if (unlikely(scsiDev.atnFlag))\r
  91         {\r
  92                 // If there was a parity error, we go\r
  93                 // back to MESSAGE_OUT first, get out parity error message, then come\r
  94                 // back here.\r
  95         }\r
  96         else if ((scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE) ||\r
  97                 (scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG))\r
  98         {\r
  99                 // Go back to the command phase and start again.\r
 100                 scsiDev.phase = COMMAND;\r
 101                 scsiDev.parityError = 0;\r
 102                 scsiDev.dataPtr = 0;\r
 103                 scsiDev.savedDataPtr = 0;\r
 104                 scsiDev.dataLen = 0;\r
 105                 scsiDev.status = GOOD;\r
 106                 transfer.blocks = 0;\r
 107                 transfer.currentBlock = 0;\r
 108         }\r
 109         else /*if (scsiDev.msgIn == MSG_COMMAND_COMPLETE)*/\r
 110         {\r
 111                 enter_BusFree();\r
 112         }\r
 113 }\r
 114 \r
 115 static void messageReject()\r
 116 {\r
 117         scsiEnterPhase(MESSAGE_IN);\r
 118         scsiWriteByte(MSG_REJECT);\r
 119 }\r
 120 \r
 121 static void enter_Status(uint8 status)\r
 122 {\r
 123         scsiDev.status = status;\r
 124         scsiDev.phase = STATUS;\r
 125 \r
 126         scsiDev.lastStatus = scsiDev.status;\r
 127         scsiDev.lastSense = scsiDev.target->sense.code;\r
 128         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 129 }\r
 130 \r
 131 void process_Status()\r
 132 {\r
 133         scsiEnterPhase(STATUS);\r
 134 \r
 135         uint8 message;\r
 136 \r
 137         uint8 control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 138         if ((scsiDev.status == GOOD) && (control & 0x01))\r
 139         {\r
 140                 // Linked command.\r
 141                 scsiDev.status = INTERMEDIATE;\r
 142                 if (control & 0x02)\r
 143                 {\r
 144                         message = MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG;\r
 145                 }\r
 146                 else\r
 147                 {\r
 148                         message = MSG_LINKED_COMMAND_COMPLETE;\r
 149                 }\r
 150         }\r
 151         else\r
 152         {\r
 153                 message = MSG_COMMAND_COMPLETE;\r
 154         }\r
 155         scsiWriteByte(scsiDev.status);\r
 156 \r
 157         scsiDev.lastStatus = scsiDev.status;\r
 158         scsiDev.lastSense = scsiDev.target->sense.code;\r
 159         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 160 \r
 161 \r
 162         // Command Complete occurs AFTER a valid status has been\r
 163         // sent. then we go bus-free.\r
 164         enter_MessageIn(message);\r
 165 }\r
 166 \r
 167 static void enter_DataIn(int len)\r
 168 {\r
 169         scsiDev.dataLen = len;\r
 170         scsiDev.phase = DATA_IN;\r
 171 }\r
 172 \r
 173 static void process_DataIn()\r
 174 {\r
 175         uint32 len;\r
 176 \r
 177         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 178         {\r
 179                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 180         }\r
 181 \r
 182         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 183         if (len > 0)\r
 184         {\r
 185                 scsiEnterPhase(DATA_IN);\r
 186                 scsiWrite(scsiDev.data + scsiDev.dataPtr, len);\r
 187                 scsiDev.dataPtr += len;\r
 188         }\r
 189 \r
 190         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 191                 (transfer.currentBlock == transfer.blocks))\r
 192         {\r
 193                 enter_Status(GOOD);\r
 194         }\r
 195 }\r
 196 \r
 197 static void process_DataOut()\r
 198 {\r
 199         uint32 len;\r
 200 \r
 201         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 202         {\r
 203                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 204         }\r
 205 \r
 206         scsiDev.parityError = 0;\r
 207         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 208         if (len > 0)\r
 209         {\r
 210                 scsiEnterPhase(DATA_OUT);\r
 211 \r
 212                 scsiRead(scsiDev.data + scsiDev.dataPtr, len);\r
 213                 scsiDev.dataPtr += len;\r
 214 \r
 215                 if (scsiDev.parityError &&\r
 216                         (scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) &&\r
 217                         (scsiDev.compatMode >= COMPAT_SCSI2))\r
 218                 {\r
 219                         scsiDev.target->sense.code = ABORTED_COMMAND;\r
 220                         scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 221                         enter_Status(CHECK_CONDITION);\r
 222                 }\r
 223         }\r
 224 \r
 225         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 226                 (transfer.currentBlock == transfer.blocks))\r
 227         {\r
 228                 if (scsiDev.postDataOutHook != NULL)\r
 229                 {\r
 230                         scsiDev.postDataOutHook();\r
 231                 }\r
 232                 else\r
 233                 {\r
 234                         enter_Status(GOOD);\r
 235                 }\r
 236         }\r
 237 }\r
 238 \r
 239 static const uint8 CmdGroupBytes[8] = {6, 10, 10, 6, 6, 12, 6, 6};\r
 240 static void process_Command()\r
 241 {\r
 242         int group;\r
 243         uint8 command;\r
 244         uint8 control;\r
 245 \r
 246         scsiEnterPhase(COMMAND);\r
 247         scsiDev.parityError = 0;\r
 248 \r
 249         memset(scsiDev.cdb, 0, sizeof(scsiDev.cdb));\r
 250         scsiDev.cdb[0] = scsiReadByte();\r
 251 \r
 252         group = scsiDev.cdb[0] >> 5;\r
 253         scsiDev.cdbLen = CmdGroupBytes[group];\r
 254         scsiRead(scsiDev.cdb + 1, scsiDev.cdbLen - 1);\r
 255 \r
 256         command = scsiDev.cdb[0];\r
 257 \r
 258         // Prefer LUN's set by IDENTIFY messages for newer hosts.\r
 259         if (scsiDev.lun < 0)\r
 260         {\r
 261                 scsiDev.lun = scsiDev.cdb[1] >> 5;\r
 262         }\r
 263 \r
 264         control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 265 \r
 266         scsiDev.cmdCount++;\r
 267         TargetConfig* cfg = scsiDev.target->cfg;\r
 268 \r
 269         if (unlikely(scsiDev.resetFlag))\r
 270         {\r
 271                 // Don't log bogus commands\r
 272                 scsiDev.cmdCount--;\r
 273                 memset(scsiDev.cdb, 0xff, sizeof(scsiDev.cdb));\r
 274                 return;\r
 275         }\r
 276         else if (scsiDev.parityError &&\r
 277                 (scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) &&\r
 278                 (scsiDev.compatMode >= COMPAT_SCSI2))\r
 279         {\r
 280                 scsiDev.target->sense.code = ABORTED_COMMAND;\r
 281                 scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 282                 enter_Status(CHECK_CONDITION);\r
 283         }\r
 284         else if ((control & 0x02) && ((control & 0x01) == 0))\r
 285         {\r
 286                 // FLAG set without LINK flag.\r
 287                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 288                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 289                 enter_Status(CHECK_CONDITION);\r
 290         }\r
 291         else if (command == 0x12)\r
 292         {\r
 293                 scsiInquiry();\r
 294         }\r
 295         else if (command == 0x03)\r
 296         {\r
 297                 // REQUEST SENSE\r
 298                 uint32 allocLength = scsiDev.cdb[4];\r
 299 \r
 300                 // As specified by the SASI and SCSI1 standard.\r
 301                 // Newer initiators won't be specifying 0 anyway.\r
 302                 if (allocLength == 0) allocLength = 4;\r
 303 \r
 304                 memset(scsiDev.data, 0, 256); // Max possible alloc length\r
 305                 scsiDev.data[0] = 0xF0;\r
 306                 scsiDev.data[2] = scsiDev.target->sense.code & 0x0F;\r
 307 \r
 308                 scsiDev.data[3] = transfer.lba >> 24;\r
 309                 scsiDev.data[4] = transfer.lba >> 16;\r
 310                 scsiDev.data[5] = transfer.lba >> 8;\r
 311                 scsiDev.data[6] = transfer.lba;\r
 312 \r
 313                 // Additional bytes if there are errors to report\r
 314                 scsiDev.data[7] = 10; // additional length\r
 315                 scsiDev.data[12] = scsiDev.target->sense.asc >> 8;\r
 316                 scsiDev.data[13] = scsiDev.target->sense.asc;\r
 317 \r
 318                 // Silently truncate results. SCSI-2 spec 8.2.14.\r
 319                 enter_DataIn(allocLength);\r
 320 \r
 321                 // This is a good time to clear out old sense information.\r
 322                 scsiDev.target->sense.code = NO_SENSE;\r
 323                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 324         }\r
 325         // Some old SCSI drivers do NOT properly support\r
 326         // unitAttention. eg. the Mac Plus would trigger a SCSI reset\r
 327         // on receiving the unit attention response on boot, thus\r
 328         // triggering another unit attention condition.\r
 329         else if (scsiDev.target->unitAttention &&\r
 330                 (scsiDev.boardCfg.flags & CONFIG_ENABLE_UNIT_ATTENTION))\r
 331         {\r
 332                 scsiDev.target->sense.code = UNIT_ATTENTION;\r
 333                 scsiDev.target->sense.asc = scsiDev.target->unitAttention;\r
 334 \r
 335                 // If initiator doesn't do REQUEST SENSE for the next command, then\r
 336                 // data is lost.\r
 337                 scsiDev.target->unitAttention = 0;\r
 338 \r
 339                 enter_Status(CHECK_CONDITION);\r
 340         }\r
 341         else if (scsiDev.lun)\r
 342         {\r
 343                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 344                 scsiDev.target->sense.asc = LOGICAL_UNIT_NOT_SUPPORTED;\r
 345                 enter_Status(CHECK_CONDITION);\r
 346         }\r
 347         else if (command == 0x17 || command == 0x16)\r
 348         {\r
 349                 doReserveRelease();\r
 350         }\r
 351         else if ((scsiDev.target->reservedId >= 0) &&\r
 352                 (scsiDev.target->reservedId != scsiDev.initiatorId))\r
 353         {\r
 354                 enter_Status(CONFLICT);\r
 355         }\r
 356         // Handle odd device types first that may override basic read and\r
 357         // write commands. Will fall-through to generic disk handling.\r
 358         else if (((cfg->deviceType == CONFIG_OPTICAL) && scsiCDRomCommand()) ||\r
 359                 ((cfg->deviceType == CONFIG_SEQUENTIAL) && scsiTapeCommand()) ||\r
 360                 ((cfg->deviceType == CONFIG_MO) && scsiMOCommand()))\r
 361         {\r
 362                 // Already handled.\r
 363         }\r
 364         else if (scsiDiskCommand())\r
 365         {\r
 366                 // Already handled.\r
 367                 // check for the performance-critical read/write\r
 368                 // commands ASAP.\r
 369         }\r
 370         else if (command == 0x1C)\r
 371         {\r
 372                 scsiReceiveDiagnostic();\r
 373         }\r
 374         else if (command == 0x1D)\r
 375         {\r
 376                 scsiSendDiagnostic();\r
 377         }\r
 378         else if (command == 0x3B)\r
 379         {\r
 380                 scsiWriteBuffer();\r
 381         }\r
 382         else if (command == 0x3C)\r
 383         {\r
 384                 scsiReadBuffer();\r
 385         }\r
 386         else if (!scsiModeCommand())\r
 387         {\r
 388                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 389                 scsiDev.target->sense.asc = INVALID_COMMAND_OPERATION_CODE;\r
 390                 enter_Status(CHECK_CONDITION);\r
 391         }\r
 392 \r
 393         // Successful\r
 394         if (scsiDev.phase == COMMAND) // No status set, and not in DATA_IN\r
 395         {\r
 396                 enter_Status(GOOD);\r
 397         }\r
 398 \r
 399 }\r
 400 \r
 401 static void doReserveRelease()\r
 402 {\r
 403         int extentReservation = scsiDev.cdb[1] & 1;\r
 404         int thirdPty = scsiDev.cdb[1] & 0x10;\r
 405         int thirdPtyId = (scsiDev.cdb[1] >> 1) & 0x7;\r
 406         uint8 command = scsiDev.cdb[0];\r
 407 \r
 408         int canRelease =\r
 409                 (!thirdPty && (scsiDev.initiatorId == scsiDev.target->reservedId)) ||\r
 410                         (thirdPty &&\r
 411                                 (scsiDev.target->reserverId == scsiDev.initiatorId) &&\r
 412                                 (scsiDev.target->reservedId == thirdPtyId)\r
 413                         );\r
 414 \r
 415         if (extentReservation)\r
 416         {\r
 417                 // Not supported.\r
 418                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 419                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 420                 enter_Status(CHECK_CONDITION);\r
 421         }\r
 422         else if (command == 0x17) // release\r
 423         {\r
 424                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 425                 {\r
 426                         scsiDev.target->reservedId = -1;\r
 427                         scsiDev.target->reserverId = -1;\r
 428                 }\r
 429                 else\r
 430                 {\r
 431                         enter_Status(CONFLICT);\r
 432                 }\r
 433         }\r
 434         else // assume reserve.\r
 435         {\r
 436                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 437                 {\r
 438                         scsiDev.target->reserverId = scsiDev.initiatorId;\r
 439                         if (thirdPty)\r
 440                         {\r
 441                                 scsiDev.target->reservedId = thirdPtyId;\r
 442                         }\r
 443                         else\r
 444                         {\r
 445                                 scsiDev.target->reservedId = scsiDev.initiatorId;\r
 446                         }\r
 447                 }\r
 448                 else\r
 449                 {\r
 450                         // Already reserved by someone else!\r
 451                         enter_Status(CONFLICT);\r
 452                 }\r
 453         }\r
 454 }\r
 455 \r
 456 static void scsiReset()\r
 457 {\r
 458         scsiDev.rstCount++;\r
 459         ledOff();\r
 460 \r
 461         scsiPhyReset();\r
 462         SCSI_Out_Ctl_Write(0);\r
 463 \r
 464         scsiDev.parityError = 0;\r
 465         scsiDev.phase = BUS_FREE;\r
 466         scsiDev.atnFlag = 0;\r
 467         scsiDev.resetFlag = 0;\r
 468         scsiDev.lun = -1;\r
 469         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 470 \r
 471         if (scsiDev.target)\r
 472         {\r
 473                 if (scsiDev.target->unitAttention != POWER_ON_RESET)\r
 474                 {\r
 475                         scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 476                 }\r
 477                 scsiDev.target->reservedId = -1;\r
 478                 scsiDev.target->reserverId = -1;\r
 479                 scsiDev.target->sense.code = NO_SENSE;\r
 480                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 481         }\r
 482         scsiDev.target = NULL;\r
 483         scsiDiskReset();\r
 484 \r
 485         scsiDev.postDataOutHook = NULL;\r
 486 \r
 487         // Sleep to allow the bus to settle down a bit.\r
 488         // We must be ready again within the "Reset to selection time" of\r
 489         // 250ms.\r
 490         // There is no guarantee that the RST line will be negated by then.\r
 491         // NOTE: We could be connected and powered by USB for configuration,\r
 492         // in which case TERMPWR cannot be supplied, and reset will ALWAYS\r
 493         // be true. Therefore, the sleep here must be slow to avoid slowing\r
 494         // USB comms\r
 495         CyDelay(1); // 1ms.\r
 496 }\r
 497 \r
 498 static void enter_SelectionPhase()\r
 499 {\r
 500         // Ignore stale versions of this flag, but ensure we know the\r
 501         // current value if the flag is still set.\r
 502         scsiDev.atnFlag = 0;\r
 503         scsiDev.parityError = 0;\r
 504         scsiDev.dataPtr = 0;\r
 505         scsiDev.savedDataPtr = 0;\r
 506         scsiDev.dataLen = 0;\r
 507         scsiDev.status = GOOD;\r
 508         scsiDev.phase = SELECTION;\r
 509         scsiDev.lun = -1;\r
 510         scsiDev.discPriv = 0;\r
 511 \r
 512         scsiDev.initiatorId = -1;\r
 513         scsiDev.target = NULL;\r
 514 \r
 515         transfer.blocks = 0;\r
 516         transfer.currentBlock = 0;\r
 517 \r
 518         scsiDev.postDataOutHook = NULL;\r
 519 }\r
 520 \r
 521 static void process_SelectionPhase()\r
 522 {\r
 523         // Selection delays.\r
 524         // Many SCSI1 samplers that use a 5380 chip need a delay of at least 1ms.\r
 525         // The Mac Plus boot-time (ie. rom code) selection abort time\r
 526         // is < 1ms and must have no delay (standard suggests 250ms abort time)\r
 527         // Most newer SCSI2 hosts don't care either way.\r
 528         if (scsiDev.boardCfg.selectionDelay == 255) // auto\r
 529         {\r
 530                 if (scsiDev.compatMode < COMPAT_SCSI2)\r
 531                 {\r
 532                         CyDelay(1);\r
 533                 }\r
 534         }\r
 535         else if (scsiDev.boardCfg.selectionDelay != 0)\r
 536         {\r
 537                 CyDelay(scsiDev.boardCfg.selectionDelay);\r
 538         }\r
 539 \r
 540         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 541         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 542         int io = SCSI_ReadPin(SCSI_In_IO);\r
 543 \r
 544         // Only read these pins AFTER SEL and BSY - we don't want to catch them\r
 545         // during a transition period.\r
 546         uint8 mask = scsiReadDBxPins();\r
 547         int maskBitCount = countBits(mask);\r
 548         int goodParity = (Lookup_OddParity[mask] == SCSI_ReadPin(SCSI_In_DBP));\r
 549         int atnFlag = SCSI_ReadFilt(SCSI_Filt_ATN);\r
 550 \r
 551         int tgtIndex;\r
 552         TargetState* target = NULL;\r
 553         for (tgtIndex = 0; tgtIndex < MAX_SCSI_TARGETS; ++tgtIndex)\r
 554         {\r
 555                 if (mask & (1 << scsiDev.targets[tgtIndex].targetId))\r
 556                 {\r
 557                         target = &scsiDev.targets[tgtIndex];\r
 558                         break;\r
 559                 }\r
 560         }\r
 561         sel &= SCSI_ReadFilt(SCSI_Filt_SEL);\r
 562         bsy |= SCSI_ReadFilt(SCSI_Filt_BSY);\r
 563         io |= SCSI_ReadPin(SCSI_In_IO);\r
 564         if (!bsy && !io && sel &&\r
 565                 target &&\r
 566                 (goodParity || !(scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) || !atnFlag) &&\r
 567                 likely(maskBitCount <= 2))\r
 568         {\r
 569                 // We've been selected!\r
 570                 // Assert BSY - Selection success!\r
 571                 // must happen within 200us (Selection abort time) of seeing our\r
 572                 // ID + SEL.\r
 573                 // (Note: the initiator will be waiting the "Selection time-out delay"\r
 574                 // for our BSY response, which is actually a very generous 250ms)\r
 575                 SCSI_SetPin(SCSI_Out_BSY);\r
 576                 ledOn();\r
 577 \r
 578                 scsiDev.target = target;\r
 579 \r
 580                 // Do we enter MESSAGE OUT immediately ? SCSI 1 and 2 standards says\r
 581                 // move to MESSAGE OUT if ATN is true before we assert BSY.\r
 582                 // The initiator should assert ATN with SEL.\r
 583                 scsiDev.atnFlag = atnFlag;\r
 584 \r
 585 \r
 586                 // Unit attention breaks many older SCSI hosts. Disable it completely\r
 587                 // for SCSI-1 (and older) hosts, regardless of our configured setting.\r
 588                 // Enable the compatability mode also as many SASI and SCSI1\r
 589                 // controllers don't generate parity bits.\r
 590                 if (!scsiDev.atnFlag)\r
 591                 {\r
 592                         target->unitAttention = 0;\r
 593                         scsiDev.compatMode = COMPAT_SCSI1;\r
 594                 }\r
 595                 else if (!(scsiDev.boardCfg.flags & CONFIG_ENABLE_SCSI2))\r
 596                 {\r
 597                         scsiDev.compatMode = COMPAT_SCSI1;\r
 598                 }\r
 599                 else if (scsiDev.compatMode == COMPAT_UNKNOWN)\r
 600                 {\r
 601                         scsiDev.compatMode = COMPAT_SCSI2;\r
 602                 }\r
 603 \r
 604                 scsiDev.selCount++;\r
 605 \r
 606 \r
 607                 // Save our initiator now that we're no longer in a time-critical\r
 608                 // section.\r
 609                 // SCSI1/SASI initiators may not set their own ID.\r
 610                 {\r
 611                         int i;\r
 612                         uint8_t initiatorMask = mask ^ (1 << target->targetId);\r
 613                         scsiDev.initiatorId = -1;\r
 614                         for (i = 0; i < 8; ++i)\r
 615                         {\r
 616                                 if (initiatorMask & (1 << i))\r
 617                                 {\r
 618                                         scsiDev.initiatorId = i;\r
 619                                         break;\r
 620                                 }\r
 621                         }\r
 622                 }\r
 623 \r
 624                 // Wait until the end of the selection phase.\r
 625                 while (likely(!scsiDev.resetFlag))\r
 626                 {\r
 627                         if (!SCSI_ReadFilt(SCSI_Filt_SEL))\r
 628                         {\r
 629                                 break;\r
 630                         }\r
 631                 }\r
 632 \r
 633                 scsiDev.phase = COMMAND;\r
 634         }\r
 635         else if (!sel)\r
 636         {\r
 637                 scsiDev.phase = BUS_BUSY;\r
 638         }\r
 639 }\r
 640 \r
 641 static void process_MessageOut()\r
 642 {\r
 643         scsiEnterPhase(MESSAGE_OUT);\r
 644 \r
 645         scsiDev.atnFlag = 0;\r
 646         scsiDev.parityError = 0;\r
 647         scsiDev.msgOut = scsiReadByte();\r
 648         scsiDev.msgCount++;\r
 649 \r
 650         if (scsiDev.parityError &&\r
 651                 (scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) &&\r
 652                 (scsiDev.compatMode >= COMPAT_SCSI2))\r
 653         {\r
 654                 // Skip the remaining message bytes, and then start the MESSAGE_OUT\r
 655                 // phase again from the start. The initiator will re-send the\r
 656                 // same set of messages.\r
 657                 while (SCSI_ReadFilt(SCSI_Filt_ATN) && !scsiDev.resetFlag)\r
 658                 {\r
 659                         scsiReadByte();\r
 660                 }\r
 661 \r
 662                 // Go-back and try the message again.\r
 663                 scsiDev.atnFlag = 1;\r
 664                 scsiDev.parityError = 0;\r
 665         }\r
 666         else if (scsiDev.msgOut == 0x00)\r
 667         {\r
 668                 // COMMAND COMPLETE. but why would the target be receiving this ? nfi.\r
 669                 enter_BusFree();\r
 670         }\r
 671         else if (scsiDev.msgOut == 0x06)\r
 672         {\r
 673                 // ABORT\r
 674                 scsiDiskReset();\r
 675                 enter_BusFree();\r
 676         }\r
 677         else if (scsiDev.msgOut == 0x0C)\r
 678         {\r
 679                 // BUS DEVICE RESET\r
 680 \r
 681                 scsiDiskReset();\r
 682 \r
 683                 scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 684 \r
 685                 // ANY initiator can reset the reservation state via this message.\r
 686                 scsiDev.target->reservedId = -1;\r
 687                 scsiDev.target->reserverId = -1;\r
 688                 enter_BusFree();\r
 689         }\r
 690         else if (scsiDev.msgOut == 0x05)\r
 691         {\r
 692                 // Initiate Detected Error\r
 693                 // Ignore for now\r
 694         }\r
 695         else if (scsiDev.msgOut == 0x0F)\r
 696         {\r
 697                 // INITIATE RECOVERY\r
 698                 // Ignore for now\r
 699         }\r
 700         else if (scsiDev.msgOut == 0x10)\r
 701         {\r
 702                 // RELEASE RECOVERY\r
 703                 // Ignore for now\r
 704                 enter_BusFree();\r
 705         }\r
 706         else if (scsiDev.msgOut == MSG_REJECT)\r
 707         {\r
 708                 // Message Reject\r
 709                 // Oh well.\r
 710                 scsiDev.resetFlag = 1;\r
 711         }\r
 712         else if (scsiDev.msgOut == 0x08)\r
 713         {\r
 714                 // NOP\r
 715         }\r
 716         else if (scsiDev.msgOut == 0x09)\r
 717         {\r
 718                 // Message Parity Error\r
 719                 // Go back and re-send the last message.\r
 720                 scsiDev.phase = MESSAGE_IN;\r
 721         }\r
 722         else if (scsiDev.msgOut & 0x80) // 0x80 -> 0xFF\r
 723         {\r
 724                 // IDENTIFY\r
 725                 if ((scsiDev.msgOut & 0x18) || // Reserved bits set.\r
 726                         (scsiDev.msgOut & 0x20))  // We don't have any target routines!\r
 727                 {\r
 728                         messageReject();\r
 729                 }\r
 730 \r
 731                 scsiDev.lun = scsiDev.msgOut & 0x7;\r
 732                 scsiDev.discPriv = \r
 733                         ((scsiDev.msgOut & 0x40) && (scsiDev.initiatorId >= 0))\r
 734                                 ? 1 : 0;\r
 735         }\r
 736         else if (scsiDev.msgOut >= 0x20 && scsiDev.msgOut <= 0x2F)\r
 737         {\r
 738                 // Two byte message. We don't support these. read and discard.\r
 739                 scsiReadByte();\r
 740 \r
 741                 if (scsiDev.msgOut == 0x23) {\r
 742                         // Ignore Wide Residue. We're only 8 bit anyway.\r
 743                 } else {\r
 744                         messageReject();\r
 745                 }\r
 746         }\r
 747         else if (scsiDev.msgOut == 0x01)\r
 748         {\r
 749                 int i;\r
 750 \r
 751                 // Extended message.\r
 752                 int msgLen = scsiReadByte();\r
 753                 if (msgLen == 0) msgLen = 256;\r
 754                 uint8_t extmsg[256];\r
 755                 for (i = 0; i < msgLen && !scsiDev.resetFlag; ++i)\r
 756                 {\r
 757                         // Discard bytes.\r
 758                         extmsg[i] = scsiReadByte();\r
 759                 }\r
 760 \r
 761                 if (extmsg[0] == 3 && msgLen == 2) // Wide Data Request\r
 762                 {\r
 763                         // Negotiate down to 8bit\r
 764                         scsiEnterPhase(MESSAGE_IN);\r
 765                         static const uint8_t WDTR[] = {0x01, 0x02, 0x03, 0x00};\r
 766                         scsiWrite(WDTR, sizeof(WDTR));\r
 767                 }\r
 768                 else if (extmsg[0] == 1 && msgLen == 3) // Synchronous data request\r
 769                 {\r
 770                         // Negotiate back to async\r
 771                         scsiEnterPhase(MESSAGE_IN);\r
 772                         static const uint8_t SDTR[] = {0x01, 0x03, 0x01, 0x00, 0x00};\r
 773                         scsiWrite(SDTR, sizeof(SDTR));\r
 774                 }\r
 775                 else\r
 776                 {\r
 777                         // Not supported\r
 778                         messageReject();\r
 779                 }\r
 780         }\r
 781         else\r
 782         {\r
 783                 messageReject();\r
 784         }\r
 785 \r
 786         // Re-check the ATN flag in case it stays asserted.\r
 787         scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 788 }\r
 789 \r
 790 void scsiPoll(void)\r
 791 {\r
 792         if (unlikely(scsiDev.resetFlag))\r
 793         {\r
 794                 scsiReset();\r
 795                 if ((scsiDev.resetFlag = SCSI_ReadFilt(SCSI_Filt_RST)))\r
 796                 {\r
 797                         // Still in reset phase. Do not try and process any commands.\r
 798                         return;\r
 799                 }\r
 800         }\r
 801 \r
 802         switch (scsiDev.phase)\r
 803         {\r
 804         case BUS_FREE:\r
 805                 if (SCSI_ReadFilt(SCSI_Filt_BSY))\r
 806                 {\r
 807                         scsiDev.phase = BUS_BUSY;\r
 808                 }\r
 809                 // The Arbitration phase is optional for SCSI1/SASI hosts if there is only\r
 810                 // one initiator in the chain. Support this by moving\r
 811                 // straight to selection if SEL is asserted.\r
 812                 // ie. the initiator won't assert BSY and it's own ID before moving to selection.\r
 813                 else if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
 814                 {\r
 815                         enter_SelectionPhase();\r
 816                 }\r
 817         break;\r
 818 \r
 819         case BUS_BUSY:\r
 820                 // Someone is using the bus. Perhaps they are trying to\r
 821                 // select us.\r
 822                 if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
 823                 {\r
 824                         enter_SelectionPhase();\r
 825                 }\r
 826                 else if (!SCSI_ReadFilt(SCSI_Filt_BSY))\r
 827                 {\r
 828                         scsiDev.phase = BUS_FREE;\r
 829                 }\r
 830         break;\r
 831 \r
 832         case ARBITRATION:\r
 833                 // TODO Support reselection.\r
 834                 break;\r
 835 \r
 836         case SELECTION:\r
 837                 process_SelectionPhase();\r
 838         break;\r
 839 \r
 840         case RESELECTION:\r
 841                 // Not currently supported!\r
 842         break;\r
 843 \r
 844         case COMMAND:\r
 845                 // Do not check ATN here. SCSI 1 & 2 initiators must set ATN\r
 846                 // and SEL together upon entering the selection phase if they\r
 847                 // want to send a message (IDENTIFY) immediately.\r
 848                 if (scsiDev.atnFlag)\r
 849                 {\r
 850                         process_MessageOut();\r
 851                 }\r
 852                 else\r
 853                 {\r
 854                         process_Command();\r
 855                 }\r
 856         break;\r
 857 \r
 858         case DATA_IN:\r
 859                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 860                 if (scsiDev.atnFlag)\r
 861                 {\r
 862                         process_MessageOut();\r
 863                 }\r
 864                 else\r
 865                 {\r
 866                         process_DataIn();\r
 867                 }\r
 868         break;\r
 869 \r
 870         case DATA_OUT:\r
 871                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 872                 if (scsiDev.atnFlag)\r
 873                 {\r
 874                         process_MessageOut();\r
 875                 }\r
 876                 else\r
 877                 {\r
 878                         process_DataOut();\r
 879                 }\r
 880         break;\r
 881 \r
 882         case STATUS:\r
 883                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 884                 if (scsiDev.atnFlag)\r
 885                 {\r
 886                         process_MessageOut();\r
 887                 }\r
 888                 else\r
 889                 {\r
 890                         process_Status();\r
 891                 }\r
 892         break;\r
 893 \r
 894         case MESSAGE_IN:\r
 895                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 896                 if (scsiDev.atnFlag)\r
 897                 {\r
 898                         process_MessageOut();\r
 899                 }\r
 900                 else\r
 901                 {\r
 902                         process_MessageIn();\r
 903                 }\r
 904 \r
 905         break;\r
 906 \r
 907         case MESSAGE_OUT:\r
 908                 process_MessageOut();\r
 909         break;\r
 910         }\r
 911 }\r
 912 \r
 913 void scsiInit()\r
 914 {\r
 915         scsiDev.atnFlag = 0;\r
 916         scsiDev.resetFlag = 1;\r
 917         scsiDev.phase = BUS_FREE;\r
 918         scsiDev.target = NULL;\r
 919         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 920 \r
 921         int i;\r
 922         for (i = 0; i < MAX_SCSI_TARGETS; ++i)\r
 923         {\r
 924                 const TargetConfig* cfg = getConfigByIndex(i);\r
 925                 if (cfg && (cfg->scsiId & CONFIG_TARGET_ENABLED))\r
 926                 {\r
 927                         scsiDev.targets[i].targetId = cfg->scsiId & CONFIG_TARGET_ID_BITS;\r
 928                         scsiDev.targets[i].cfg = cfg;\r
 929 \r
 930                         scsiDev.targets[i].liveCfg.bytesPerSector = cfg->bytesPerSector;\r
 931                 }\r
 932                 else\r
 933                 {\r
 934                         scsiDev.targets[i].targetId = 0xff;\r
 935                         scsiDev.targets[i].cfg = NULL;\r
 936                 }\r
 937                 scsiDev.targets[i].reservedId = -1;\r
 938                 scsiDev.targets[i].reserverId = -1;\r
 939                 scsiDev.targets[i].unitAttention = POWER_ON_RESET;\r
 940                 scsiDev.targets[i].sense.code = NO_SENSE;\r
 941                 scsiDev.targets[i].sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 942         }\r
 943 }\r
 944 \r
 945 void scsiDisconnect()\r
 946 {\r
 947         scsiEnterPhase(MESSAGE_IN);\r
 948         scsiWriteByte(0x02); // save data pointer\r
 949         scsiWriteByte(0x04); // disconnect msg.\r
 950 \r
 951         // For now, the caller is responsible for tracking the disconnected\r
 952         // state, and calling scsiReconnect.\r
 953         // Ideally the client would exit their loop and we'd implement this\r
 954         // as part of scsiPoll\r
 955         int phase = scsiDev.phase;\r
 956         enter_BusFree();\r
 957         scsiDev.phase = phase;\r
 958 }\r
 959 \r
 960 int scsiReconnect()\r
 961 {\r
 962         int reconnected = 0;\r
 963 \r
 964         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 965         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 966         if (!sel && !bsy)\r
 967         {\r
 968                 CyDelayUs(1);\r
 969                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 970                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 971         }\r
 972 \r
 973         if (!sel && !bsy)\r
 974         {\r
 975                 // Arbitrate.\r
 976                 ledOn();\r
 977                 uint8_t scsiIdMask = 1 << scsiDev.target->targetId;\r
 978                 SCSI_Out_Bits_Write(scsiIdMask);\r
 979                 SCSI_Out_Ctl_Write(1); // Write bits manually.\r
 980                 SCSI_SetPin(SCSI_Out_BSY);\r
 981 \r
 982                 CyDelayUs(3); // arbitrate delay. 2.4us.\r
 983 \r
 984                 uint8_t dbx = scsiReadDBxPins();\r
 985                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 986                 if (sel || ((dbx ^ scsiIdMask) > scsiIdMask))\r
 987                 {\r
 988                         // Lost arbitration.\r
 989                         SCSI_Out_Ctl_Write(0);\r
 990                         SCSI_ClearPin(SCSI_Out_BSY);\r
 991                         ledOff();\r
 992                 }\r
 993                 else\r
 994                 {\r
 995                         // Won arbitration\r
 996                         SCSI_SetPin(SCSI_Out_SEL);\r
 997                         CyDelayUs(1); // Bus clear + Bus settle.\r
 998 \r
 999                         // Reselection phase\r
1000                         SCSI_CTL_PHASE_Write(__scsiphase_io);\r
1001                         SCSI_Out_Bits_Write(scsiIdMask | (1 << scsiDev.initiatorId));\r
1002                         scsiDeskewDelay(); // 2 deskew delays\r
1003                         scsiDeskewDelay(); // 2 deskew delays\r
1004                         SCSI_ClearPin(SCSI_Out_BSY);\r
1005                         CyDelayUs(1);  // Bus Settle Delay\r
1006 \r
1007                         uint32_t waitStart_ms = getTime_ms();\r
1008                         bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1009                         // Wait for initiator.\r
1010                         while (\r
1011                                 !bsy &&\r
1012                                 !scsiDev.resetFlag &&\r
1013                                 (elapsedTime_ms(waitStart_ms) < 250))\r
1014                         {\r
1015                                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1016                         }\r
1017 \r
1018                         if (bsy)\r
1019                         {\r
1020                                 SCSI_SetPin(SCSI_Out_BSY);\r
1021                                 scsiDeskewDelay(); // 2 deskew delays\r
1022                                 scsiDeskewDelay(); // 2 deskew delays\r
1023                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1024 \r
1025                                 // Prepare for the initial IDENTIFY message.\r
1026                                 SCSI_Out_Ctl_Write(0);\r
1027                                 scsiEnterPhase(MESSAGE_IN);\r
1028 \r
1029                                 // Send identify command\r
1030                                 scsiWriteByte(0x80);\r
1031 \r
1032                                 scsiEnterPhase(scsiDev.phase);\r
1033                                 reconnected = 1;\r
1034                         }\r
1035                         else\r
1036                         {\r
1037                                 // reselect timeout.\r
1038                                 SCSI_Out_Ctl_Write(0);\r
1039                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1040                                 SCSI_CTL_PHASE_Write(0);\r
1041                                 ledOff();\r
1042                         }\r
1043                 }\r
1044         }\r
1045         return reconnected;\r
1046 }\r
1047 \r
1048 #pragma GCC pop_options\r