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 #include "tape.h"\r
  35 #include "mo.h"\r
  36 \r
  37 #include <string.h>\r
  38 \r
  39 // Global SCSI device state.\r
  40 ScsiDevice scsiDev;\r
  41 \r
  42 static void enter_SelectionPhase(void);\r
  43 static void process_SelectionPhase(void);\r
  44 static void enter_BusFree(void);\r
  45 static void enter_MessageIn(uint8 message);\r
  46 static void enter_Status(uint8 status);\r
  47 static void enter_DataIn(int len);\r
  48 static void process_DataIn(void);\r
  49 static void process_DataOut(void);\r
  50 static void process_Command(void);\r
  51 \r
  52 static void doReserveRelease(void);\r
  53 \r
  54 static void enter_BusFree()\r
  55 {\r
  56         // This delay probably isn't needed for most SCSI hosts, but it won't\r
  57         // hurt either. It's possible some of the samplers needed this delay.\r
  58         if (scsiDev.compatMode < COMPAT_SCSI2)\r
  59         {\r
  60                 CyDelayUs(2);\r
  61         }\r
  62 \r
  63         if (scsiDev.status != GOOD && isDebugEnabled())\r
  64         {\r
  65                 // We want to capture debug information for failure cases.\r
  66                 CyDelay(64);\r
  67         }\r
  68 \r
  69         SCSI_ClearPin(SCSI_Out_BSY);\r
  70         // We now have a Bus Clear Delay of 800ns to release remaining signals.\r
  71         SCSI_CTL_PHASE_Write(0);\r
  72 \r
  73         // Wait for the initiator to cease driving signals\r
  74         // Bus settle delay + bus clear delay = 1200ns\r
  75         CyDelayUs(2);\r
  76 \r
  77         ledOff();\r
  78         scsiDev.phase = BUS_FREE;\r
  79 }\r
  80 \r
  81 static void enter_MessageIn(uint8 message)\r
  82 {\r
  83         scsiDev.msgIn = message;\r
  84         scsiDev.phase = MESSAGE_IN;\r
  85 }\r
  86 \r
  87 void process_MessageIn()\r
  88 {\r
  89         scsiEnterPhase(MESSAGE_IN);\r
  90         scsiWriteByte(scsiDev.msgIn);\r
  91 \r
  92         if (unlikely(scsiDev.atnFlag))\r
  93         {\r
  94                 // If there was a parity error, we go\r
  95                 // back to MESSAGE_OUT first, get out parity error message, then come\r
  96                 // back here.\r
  97         }\r
  98         else if ((scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE) ||\r
  99                 (scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG))\r
 100         {\r
 101                 // Go back to the command phase and start again.\r
 102                 scsiDev.phase = COMMAND;\r
 103                 scsiDev.parityError = 0;\r
 104                 scsiDev.dataPtr = 0;\r
 105                 scsiDev.savedDataPtr = 0;\r
 106                 scsiDev.dataLen = 0;\r
 107                 scsiDev.status = GOOD;\r
 108                 transfer.blocks = 0;\r
 109                 transfer.currentBlock = 0;\r
 110         }\r
 111         else /*if (scsiDev.msgIn == MSG_COMMAND_COMPLETE)*/\r
 112         {\r
 113                 enter_BusFree();\r
 114         }\r
 115 }\r
 116 \r
 117 static void messageReject()\r
 118 {\r
 119         scsiEnterPhase(MESSAGE_IN);\r
 120         scsiWriteByte(MSG_REJECT);\r
 121 }\r
 122 \r
 123 static void enter_Status(uint8 status)\r
 124 {\r
 125         scsiDev.status = status;\r
 126         scsiDev.phase = STATUS;\r
 127 \r
 128         scsiDev.lastStatus = scsiDev.status;\r
 129         scsiDev.lastSense = scsiDev.target->sense.code;\r
 130         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 131 }\r
 132 \r
 133 void process_Status()\r
 134 {\r
 135         scsiEnterPhase(STATUS);\r
 136 \r
 137         uint8 message;\r
 138 \r
 139         uint8 control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 140         if ((scsiDev.status == GOOD) && (control & 0x01))\r
 141         {\r
 142                 // Linked command.\r
 143                 scsiDev.status = INTERMEDIATE;\r
 144                 if (control & 0x02)\r
 145                 {\r
 146                         message = MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG;\r
 147                 }\r
 148                 else\r
 149                 {\r
 150                         message = MSG_LINKED_COMMAND_COMPLETE;\r
 151                 }\r
 152         }\r
 153         else\r
 154         {\r
 155                 message = MSG_COMMAND_COMPLETE;\r
 156         }\r
 157         scsiWriteByte(scsiDev.status);\r
 158 \r
 159         scsiDev.lastStatus = scsiDev.status;\r
 160         scsiDev.lastSense = scsiDev.target->sense.code;\r
 161         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 162 \r
 163 \r
 164         // Command Complete occurs AFTER a valid status has been\r
 165         // sent. then we go bus-free.\r
 166         enter_MessageIn(message);\r
 167 }\r
 168 \r
 169 static void enter_DataIn(int len)\r
 170 {\r
 171         scsiDev.dataLen = len;\r
 172         scsiDev.phase = DATA_IN;\r
 173 }\r
 174 \r
 175 static void process_DataIn()\r
 176 {\r
 177         uint32 len;\r
 178 \r
 179         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 180         {\r
 181                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 182         }\r
 183 \r
 184         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 185         if (len > 0)\r
 186         {\r
 187                 scsiEnterPhase(DATA_IN);\r
 188                 scsiWrite(scsiDev.data + scsiDev.dataPtr, len);\r
 189                 scsiDev.dataPtr += len;\r
 190         }\r
 191 \r
 192         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 193                 (transfer.currentBlock == transfer.blocks))\r
 194         {\r
 195                 enter_Status(GOOD);\r
 196         }\r
 197 }\r
 198 \r
 199 static void process_DataOut()\r
 200 {\r
 201         uint32 len;\r
 202 \r
 203         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 204         {\r
 205                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 206         }\r
 207 \r
 208         scsiDev.parityError = 0;\r
 209         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 210         if (len > 0)\r
 211         {\r
 212                 scsiEnterPhase(DATA_OUT);\r
 213 \r
 214                 scsiRead(scsiDev.data + scsiDev.dataPtr, len);\r
 215                 scsiDev.dataPtr += len;\r
 216 \r
 217                 if (scsiDev.parityError &&\r
 218                         (scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) &&\r
 219                         (scsiDev.compatMode >= COMPAT_SCSI2))\r
 220                 {\r
 221                         scsiDev.target->sense.code = ABORTED_COMMAND;\r
 222                         scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 223                         enter_Status(CHECK_CONDITION);\r
 224                 }\r
 225         }\r
 226 \r
 227         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 228                 (transfer.currentBlock == transfer.blocks))\r
 229         {\r
 230                 if (scsiDev.postDataOutHook != NULL)\r
 231                 {\r
 232                         scsiDev.postDataOutHook();\r
 233                 }\r
 234                 else\r
 235                 {\r
 236                         enter_Status(GOOD);\r
 237                 }\r
 238         }\r
 239 }\r
 240 \r
 241 static const uint8 CmdGroupBytes[8] = {6, 10, 10, 6, 6, 12, 6, 6};\r
 242 static void process_Command()\r
 243 {\r
 244         int group;\r
 245         uint8 command;\r
 246         uint8 control;\r
 247 \r
 248         scsiEnterPhase(COMMAND);\r
 249         scsiDev.parityError = 0;\r
 250 \r
 251         memset(scsiDev.cdb, 0, sizeof(scsiDev.cdb));\r
 252         scsiDev.cdb[0] = scsiReadByte();\r
 253 \r
 254         group = scsiDev.cdb[0] >> 5;\r
 255         scsiDev.cdbLen = CmdGroupBytes[group];\r
 256         scsiRead(scsiDev.cdb + 1, scsiDev.cdbLen - 1);\r
 257 \r
 258         command = scsiDev.cdb[0];\r
 259 \r
 260         // Prefer LUN's set by IDENTIFY messages for newer hosts.\r
 261         if (scsiDev.lun < 0)\r
 262         {\r
 263                 scsiDev.lun = scsiDev.cdb[1] >> 5;\r
 264         }\r
 265 \r
 266         control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 267 \r
 268         scsiDev.cmdCount++;\r
 269         TargetConfig* cfg = scsiDev.target->cfg;\r
 270 \r
 271         if (unlikely(scsiDev.resetFlag))\r
 272         {\r
 273                 // Don't log bogus commands\r
 274                 scsiDev.cmdCount--;\r
 275                 memset(scsiDev.cdb, 0xff, sizeof(scsiDev.cdb));\r
 276                 return;\r
 277         }\r
 278         else if (scsiDev.parityError &&\r
 279                 (scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) &&\r
 280                 (scsiDev.compatMode >= COMPAT_SCSI2))\r
 281         {\r
 282                 scsiDev.target->sense.code = ABORTED_COMMAND;\r
 283                 scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 284                 enter_Status(CHECK_CONDITION);\r
 285         }\r
 286         else if ((control & 0x02) && ((control & 0x01) == 0))\r
 287         {\r
 288                 // FLAG set without LINK flag.\r
 289                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 290                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 291                 enter_Status(CHECK_CONDITION);\r
 292         }\r
 293         else if (command == 0x12)\r
 294         {\r
 295                 scsiInquiry();\r
 296         }\r
 297         else if (command == 0x03)\r
 298         {\r
 299                 // REQUEST SENSE\r
 300                 uint32 allocLength = scsiDev.cdb[4];\r
 301 \r
 302                 // As specified by the SASI and SCSI1 standard.\r
 303                 // Newer initiators won't be specifying 0 anyway.\r
 304                 if (allocLength == 0) allocLength = 4;\r
 305 \r
 306                 memset(scsiDev.data, 0, 256); // Max possible alloc length\r
 307                 scsiDev.data[0] = 0xF0;\r
 308                 scsiDev.data[2] = scsiDev.target->sense.code & 0x0F;\r
 309 \r
 310                 scsiDev.data[3] = transfer.lba >> 24;\r
 311                 scsiDev.data[4] = transfer.lba >> 16;\r
 312                 scsiDev.data[5] = transfer.lba >> 8;\r
 313                 scsiDev.data[6] = transfer.lba;\r
 314 \r
 315                 // Additional bytes if there are errors to report\r
 316                 scsiDev.data[7] = 10; // additional length\r
 317                 scsiDev.data[12] = scsiDev.target->sense.asc >> 8;\r
 318                 scsiDev.data[13] = scsiDev.target->sense.asc;\r
 319 \r
 320                 // Silently truncate results. SCSI-2 spec 8.2.14.\r
 321                 enter_DataIn(allocLength);\r
 322 \r
 323                 // This is a good time to clear out old sense information.\r
 324                 scsiDev.target->sense.code = NO_SENSE;\r
 325                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 326         }\r
 327         // Some old SCSI drivers do NOT properly support\r
 328         // unitAttention. eg. the Mac Plus would trigger a SCSI reset\r
 329         // on receiving the unit attention response on boot, thus\r
 330         // triggering another unit attention condition.\r
 331         else if (scsiDev.target->unitAttention &&\r
 332                 (scsiDev.boardCfg.flags & CONFIG_ENABLE_UNIT_ATTENTION))\r
 333         {\r
 334                 scsiDev.target->sense.code = UNIT_ATTENTION;\r
 335                 scsiDev.target->sense.asc = scsiDev.target->unitAttention;\r
 336 \r
 337                 // If initiator doesn't do REQUEST SENSE for the next command, then\r
 338                 // data is lost.\r
 339                 scsiDev.target->unitAttention = 0;\r
 340 \r
 341                 enter_Status(CHECK_CONDITION);\r
 342         }\r
 343         else if (scsiDev.lun)\r
 344         {\r
 345                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 346                 scsiDev.target->sense.asc = LOGICAL_UNIT_NOT_SUPPORTED;\r
 347                 enter_Status(CHECK_CONDITION);\r
 348         }\r
 349         else if (command == 0x17 || command == 0x16)\r
 350         {\r
 351                 doReserveRelease();\r
 352         }\r
 353         else if ((scsiDev.target->reservedId >= 0) &&\r
 354                 (scsiDev.target->reservedId != scsiDev.initiatorId))\r
 355         {\r
 356                 enter_Status(CONFLICT);\r
 357         }\r
 358         // Handle odd device types first that may override basic read and\r
 359         // write commands. Will fall-through to generic disk handling.\r
 360         else if (((cfg->deviceType == CONFIG_OPTICAL) && scsiCDRomCommand()) ||\r
 361                 ((cfg->deviceType == CONFIG_SEQUENTIAL) && scsiTapeCommand()) ||\r
 362                 ((cfg->deviceType == CONFIG_MO) && scsiMOCommand()))\r
 363         {\r
 364                 // Already handled.\r
 365         }\r
 366         else if (scsiDiskCommand())\r
 367         {\r
 368                 // Already handled.\r
 369                 // check for the performance-critical read/write\r
 370                 // commands ASAP.\r
 371         }\r
 372         else if (command == 0x1C)\r
 373         {\r
 374                 scsiReceiveDiagnostic();\r
 375         }\r
 376         else if (command == 0x1D)\r
 377         {\r
 378                 scsiSendDiagnostic();\r
 379         }\r
 380         else if (command == 0x3B)\r
 381         {\r
 382                 scsiWriteBuffer();\r
 383         }\r
 384         else if (command == 0x3C)\r
 385         {\r
 386                 scsiReadBuffer();\r
 387         }\r
 388         else if (!scsiModeCommand())\r
 389         {\r
 390                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 391                 scsiDev.target->sense.asc = INVALID_COMMAND_OPERATION_CODE;\r
 392                 enter_Status(CHECK_CONDITION);\r
 393         }\r
 394 \r
 395         // Successful\r
 396         if (scsiDev.phase == COMMAND) // No status set, and not in DATA_IN\r
 397         {\r
 398                 enter_Status(GOOD);\r
 399         }\r
 400 \r
 401 }\r
 402 \r
 403 static void doReserveRelease()\r
 404 {\r
 405         int extentReservation = scsiDev.cdb[1] & 1;\r
 406         int thirdPty = scsiDev.cdb[1] & 0x10;\r
 407         int thirdPtyId = (scsiDev.cdb[1] >> 1) & 0x7;\r
 408         uint8 command = scsiDev.cdb[0];\r
 409 \r
 410         int canRelease =\r
 411                 (!thirdPty && (scsiDev.initiatorId == scsiDev.target->reservedId)) ||\r
 412                         (thirdPty &&\r
 413                                 (scsiDev.target->reserverId == scsiDev.initiatorId) &&\r
 414                                 (scsiDev.target->reservedId == thirdPtyId)\r
 415                         );\r
 416 \r
 417         if (extentReservation)\r
 418         {\r
 419                 // Not supported.\r
 420                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 421                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 422                 enter_Status(CHECK_CONDITION);\r
 423         }\r
 424         else if (command == 0x17) // release\r
 425         {\r
 426                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 427                 {\r
 428                         scsiDev.target->reservedId = -1;\r
 429                         scsiDev.target->reserverId = -1;\r
 430                 }\r
 431                 else\r
 432                 {\r
 433                         enter_Status(CONFLICT);\r
 434                 }\r
 435         }\r
 436         else // assume reserve.\r
 437         {\r
 438                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 439                 {\r
 440                         scsiDev.target->reserverId = scsiDev.initiatorId;\r
 441                         if (thirdPty)\r
 442                         {\r
 443                                 scsiDev.target->reservedId = thirdPtyId;\r
 444                         }\r
 445                         else\r
 446                         {\r
 447                                 scsiDev.target->reservedId = scsiDev.initiatorId;\r
 448                         }\r
 449                 }\r
 450                 else\r
 451                 {\r
 452                         // Already reserved by someone else!\r
 453                         enter_Status(CONFLICT);\r
 454                 }\r
 455         }\r
 456 }\r
 457 \r
 458 static void scsiReset()\r
 459 {\r
 460         scsiDev.rstCount++;\r
 461         ledOff();\r
 462 \r
 463         scsiPhyReset();\r
 464         SCSI_Out_Ctl_Write(0);\r
 465 \r
 466         scsiDev.parityError = 0;\r
 467         scsiDev.phase = BUS_FREE;\r
 468         scsiDev.atnFlag = 0;\r
 469         scsiDev.resetFlag = 0;\r
 470         scsiDev.lun = -1;\r
 471         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 472 \r
 473         if (scsiDev.target)\r
 474         {\r
 475                 if (scsiDev.target->unitAttention != POWER_ON_RESET)\r
 476                 {\r
 477                         scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 478                 }\r
 479                 scsiDev.target->reservedId = -1;\r
 480                 scsiDev.target->reserverId = -1;\r
 481                 scsiDev.target->sense.code = NO_SENSE;\r
 482                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 483         }\r
 484         scsiDev.target = NULL;\r
 485         scsiDiskReset();\r
 486 \r
 487         scsiDev.postDataOutHook = NULL;\r
 488 \r
 489         // Sleep to allow the bus to settle down a bit.\r
 490         // We must be ready again within the "Reset to selection time" of\r
 491         // 250ms.\r
 492         // There is no guarantee that the RST line will be negated by then.\r
 493         // NOTE: We could be connected and powered by USB for configuration,\r
 494         // in which case TERMPWR cannot be supplied, and reset will ALWAYS\r
 495         // be true. Therefore, the sleep here must be slow to avoid slowing\r
 496         // USB comms\r
 497         CyDelay(1); // 1ms.\r
 498 }\r
 499 \r
 500 static void enter_SelectionPhase()\r
 501 {\r
 502         // Ignore stale versions of this flag, but ensure we know the\r
 503         // current value if the flag is still set.\r
 504         scsiDev.atnFlag = 0;\r
 505         scsiDev.parityError = 0;\r
 506         scsiDev.dataPtr = 0;\r
 507         scsiDev.savedDataPtr = 0;\r
 508         scsiDev.dataLen = 0;\r
 509         scsiDev.status = GOOD;\r
 510         scsiDev.phase = SELECTION;\r
 511         scsiDev.lun = -1;\r
 512         scsiDev.discPriv = 0;\r
 513 \r
 514         scsiDev.initiatorId = -1;\r
 515         scsiDev.target = NULL;\r
 516 \r
 517         transfer.blocks = 0;\r
 518         transfer.currentBlock = 0;\r
 519 \r
 520         scsiDev.postDataOutHook = NULL;\r
 521 }\r
 522 \r
 523 static void process_SelectionPhase()\r
 524 {\r
 525         // Selection delays.\r
 526         // Many SCSI1 samplers that use a 5380 chip need a delay of at least 1ms.\r
 527         // The Mac Plus boot-time (ie. rom code) selection abort time\r
 528         // is < 1ms and must have no delay (standard suggests 250ms abort time)\r
 529         // Most newer SCSI2 hosts don't care either way.\r
 530         if (scsiDev.boardCfg.selectionDelay == 255) // auto\r
 531         {\r
 532                 if (scsiDev.compatMode < COMPAT_SCSI2)\r
 533                 {\r
 534                         CyDelay(1);\r
 535                 }\r
 536         }\r
 537         else if (scsiDev.boardCfg.selectionDelay != 0)\r
 538         {\r
 539                 CyDelay(scsiDev.boardCfg.selectionDelay);\r
 540         }\r
 541 \r
 542         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 543         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 544         int io = SCSI_ReadPin(SCSI_In_IO);\r
 545 \r
 546         // Only read these pins AFTER SEL and BSY - we don't want to catch them\r
 547         // during a transition period.\r
 548         uint8 mask = scsiReadDBxPins();\r
 549         int maskBitCount = countBits(mask);\r
 550         int goodParity = (Lookup_OddParity[mask] == SCSI_ReadPin(SCSI_In_DBP));\r
 551         int atnFlag = SCSI_ReadFilt(SCSI_Filt_ATN);\r
 552 \r
 553         int tgtIndex;\r
 554         TargetState* target = NULL;\r
 555         for (tgtIndex = 0; tgtIndex < MAX_SCSI_TARGETS; ++tgtIndex)\r
 556         {\r
 557                 if (mask & (1 << scsiDev.targets[tgtIndex].targetId))\r
 558                 {\r
 559                         target = &scsiDev.targets[tgtIndex];\r
 560                         break;\r
 561                 }\r
 562         }\r
 563         sel &= SCSI_ReadFilt(SCSI_Filt_SEL);\r
 564         bsy |= SCSI_ReadFilt(SCSI_Filt_BSY);\r
 565         io |= SCSI_ReadPin(SCSI_In_IO);\r
 566         if (!bsy && !io && sel &&\r
 567                 target &&\r
 568                 (goodParity || !(scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) || !atnFlag) &&\r
 569                 likely(maskBitCount <= 2))\r
 570         {\r
 571                 // We've been selected!\r
 572                 // Assert BSY - Selection success!\r
 573                 // must happen within 200us (Selection abort time) of seeing our\r
 574                 // ID + SEL.\r
 575                 // (Note: the initiator will be waiting the "Selection time-out delay"\r
 576                 // for our BSY response, which is actually a very generous 250ms)\r
 577                 SCSI_SetPin(SCSI_Out_BSY);\r
 578                 ledOn();\r
 579 \r
 580                 scsiDev.target = target;\r
 581 \r
 582                 // Do we enter MESSAGE OUT immediately ? SCSI 1 and 2 standards says\r
 583                 // move to MESSAGE OUT if ATN is true before we assert BSY.\r
 584                 // The initiator should assert ATN with SEL.\r
 585                 scsiDev.atnFlag = atnFlag;\r
 586 \r
 587 \r
 588                 // Unit attention breaks many older SCSI hosts. Disable it completely\r
 589                 // for SCSI-1 (and older) hosts, regardless of our configured setting.\r
 590                 // Enable the compatability mode also as many SASI and SCSI1\r
 591                 // controllers don't generate parity bits.\r
 592                 if (!scsiDev.atnFlag)\r
 593                 {\r
 594                         target->unitAttention = 0;\r
 595                         scsiDev.compatMode = COMPAT_SCSI1;\r
 596                 }\r
 597                 else if (!(scsiDev.boardCfg.flags & CONFIG_ENABLE_SCSI2))\r
 598                 {\r
 599                         scsiDev.compatMode = COMPAT_SCSI1;\r
 600                 }\r
 601                 else if (scsiDev.compatMode == COMPAT_UNKNOWN)\r
 602                 {\r
 603                         scsiDev.compatMode = COMPAT_SCSI2;\r
 604                 }\r
 605 \r
 606                 scsiDev.selCount++;\r
 607 \r
 608 \r
 609                 // Save our initiator now that we're no longer in a time-critical\r
 610                 // section.\r
 611                 // SCSI1/SASI initiators may not set their own ID.\r
 612                 {\r
 613                         int i;\r
 614                         uint8_t initiatorMask = mask ^ (1 << target->targetId);\r
 615                         scsiDev.initiatorId = -1;\r
 616                         for (i = 0; i < 8; ++i)\r
 617                         {\r
 618                                 if (initiatorMask & (1 << i))\r
 619                                 {\r
 620                                         scsiDev.initiatorId = i;\r
 621                                         break;\r
 622                                 }\r
 623                         }\r
 624                 }\r
 625 \r
 626                 // Wait until the end of the selection phase.\r
 627                 while (likely(!scsiDev.resetFlag))\r
 628                 {\r
 629                         if (!SCSI_ReadFilt(SCSI_Filt_SEL))\r
 630                         {\r
 631                                 break;\r
 632                         }\r
 633                 }\r
 634 \r
 635                 scsiDev.phase = COMMAND;\r
 636         }\r
 637         else if (!sel)\r
 638         {\r
 639                 scsiDev.phase = BUS_BUSY;\r
 640         }\r
 641 }\r
 642 \r
 643 static void process_MessageOut()\r
 644 {\r
 645         scsiEnterPhase(MESSAGE_OUT);\r
 646 \r
 647         scsiDev.atnFlag = 0;\r
 648         scsiDev.parityError = 0;\r
 649         scsiDev.msgOut = scsiReadByte();\r
 650         scsiDev.msgCount++;\r
 651 \r
 652         if (scsiDev.parityError &&\r
 653                 (scsiDev.boardCfg.flags & CONFIG_ENABLE_PARITY) &&\r
 654                 (scsiDev.compatMode >= COMPAT_SCSI2))\r
 655         {\r
 656                 // Skip the remaining message bytes, and then start the MESSAGE_OUT\r
 657                 // phase again from the start. The initiator will re-send the\r
 658                 // same set of messages.\r
 659                 while (SCSI_ReadFilt(SCSI_Filt_ATN) && !scsiDev.resetFlag)\r
 660                 {\r
 661                         scsiReadByte();\r
 662                 }\r
 663 \r
 664                 // Go-back and try the message again.\r
 665                 scsiDev.atnFlag = 1;\r
 666                 scsiDev.parityError = 0;\r
 667         }\r
 668         else if (scsiDev.msgOut == 0x00)\r
 669         {\r
 670                 // COMMAND COMPLETE. but why would the target be receiving this ? nfi.\r
 671                 enter_BusFree();\r
 672         }\r
 673         else if (scsiDev.msgOut == 0x06)\r
 674         {\r
 675                 // ABORT\r
 676                 scsiDiskReset();\r
 677                 enter_BusFree();\r
 678         }\r
 679         else if (scsiDev.msgOut == 0x0C)\r
 680         {\r
 681                 // BUS DEVICE RESET\r
 682 \r
 683                 scsiDiskReset();\r
 684 \r
 685                 scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 686 \r
 687                 // ANY initiator can reset the reservation state via this message.\r
 688                 scsiDev.target->reservedId = -1;\r
 689                 scsiDev.target->reserverId = -1;\r
 690                 enter_BusFree();\r
 691         }\r
 692         else if (scsiDev.msgOut == 0x05)\r
 693         {\r
 694                 // Initiate Detected Error\r
 695                 // Ignore for now\r
 696         }\r
 697         else if (scsiDev.msgOut == 0x0F)\r
 698         {\r
 699                 // INITIATE RECOVERY\r
 700                 // Ignore for now\r
 701         }\r
 702         else if (scsiDev.msgOut == 0x10)\r
 703         {\r
 704                 // RELEASE RECOVERY\r
 705                 // Ignore for now\r
 706                 enter_BusFree();\r
 707         }\r
 708         else if (scsiDev.msgOut == MSG_REJECT)\r
 709         {\r
 710                 // Message Reject\r
 711                 // Oh well.\r
 712                 scsiDev.resetFlag = 1;\r
 713         }\r
 714         else if (scsiDev.msgOut == 0x08)\r
 715         {\r
 716                 // NOP\r
 717         }\r
 718         else if (scsiDev.msgOut == 0x09)\r
 719         {\r
 720                 // Message Parity Error\r
 721                 // Go back and re-send the last message.\r
 722                 scsiDev.phase = MESSAGE_IN;\r
 723         }\r
 724         else if (scsiDev.msgOut & 0x80) // 0x80 -> 0xFF\r
 725         {\r
 726                 // IDENTIFY\r
 727                 if ((scsiDev.msgOut & 0x18) || // Reserved bits set.\r
 728                         (scsiDev.msgOut & 0x20))  // We don't have any target routines!\r
 729                 {\r
 730                         messageReject();\r
 731                 }\r
 732 \r
 733                 scsiDev.lun = scsiDev.msgOut & 0x7;\r
 734                 scsiDev.discPriv = \r
 735                         ((scsiDev.msgOut & 0x40) && (scsiDev.initiatorId >= 0))\r
 736                                 ? 1 : 0;\r
 737         }\r
 738         else if (scsiDev.msgOut >= 0x20 && scsiDev.msgOut <= 0x2F)\r
 739         {\r
 740                 // Two byte message. We don't support these. read and discard.\r
 741                 scsiReadByte();\r
 742 \r
 743                 if (scsiDev.msgOut == 0x23) {\r
 744                         // Ignore Wide Residue. We're only 8 bit anyway.\r
 745                 } else {\r
 746                         messageReject();\r
 747                 }\r
 748         }\r
 749         else if (scsiDev.msgOut == 0x01)\r
 750         {\r
 751                 int i;\r
 752 \r
 753                 // Extended message.\r
 754                 int msgLen = scsiReadByte();\r
 755                 if (msgLen == 0) msgLen = 256;\r
 756                 uint8_t extmsg[256];\r
 757                 for (i = 0; i < msgLen && !scsiDev.resetFlag; ++i)\r
 758                 {\r
 759                         // Discard bytes.\r
 760                         extmsg[i] = scsiReadByte();\r
 761                 }\r
 762 \r
 763                 if (extmsg[0] == 3 && msgLen == 2) // Wide Data Request\r
 764                 {\r
 765                         // Negotiate down to 8bit\r
 766                         scsiEnterPhase(MESSAGE_IN);\r
 767                         static const uint8_t WDTR[] = {0x01, 0x02, 0x03, 0x00};\r
 768                         scsiWrite(WDTR, sizeof(WDTR));\r
 769                 }\r
 770                 else if (extmsg[0] == 1 && msgLen == 3) // Synchronous data request\r
 771                 {\r
 772                         // Negotiate back to async\r
 773                         scsiEnterPhase(MESSAGE_IN);\r
 774                         static const uint8_t SDTR[] = {0x01, 0x03, 0x01, 0x00, 0x00};\r
 775                         scsiWrite(SDTR, sizeof(SDTR));\r
 776                 }\r
 777                 else\r
 778                 {\r
 779                         // Not supported\r
 780                         messageReject();\r
 781                 }\r
 782         }\r
 783         else\r
 784         {\r
 785                 messageReject();\r
 786         }\r
 787 \r
 788         // Re-check the ATN flag in case it stays asserted.\r
 789         scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 790 }\r
 791 \r
 792 void scsiPoll(void)\r
 793 {\r
 794         if (unlikely(scsiDev.resetFlag))\r
 795         {\r
 796                 scsiReset();\r
 797                 if ((scsiDev.resetFlag = SCSI_ReadFilt(SCSI_Filt_RST)))\r
 798                 {\r
 799                         // Still in reset phase. Do not try and process any commands.\r
 800                         return;\r
 801                 }\r
 802         }\r
 803 \r
 804         switch (scsiDev.phase)\r
 805         {\r
 806         case BUS_FREE:\r
 807                 if (SCSI_ReadFilt(SCSI_Filt_BSY))\r
 808                 {\r
 809                         scsiDev.phase = BUS_BUSY;\r
 810                 }\r
 811                 // The Arbitration phase is optional for SCSI1/SASI hosts if there is only\r
 812                 // one initiator in the chain. Support this by moving\r
 813                 // straight to selection if SEL is asserted.\r
 814                 // ie. the initiator won't assert BSY and it's own ID before moving to selection.\r
 815                 else if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
 816                 {\r
 817                         enter_SelectionPhase();\r
 818                 }\r
 819         break;\r
 820 \r
 821         case BUS_BUSY:\r
 822                 // Someone is using the bus. Perhaps they are trying to\r
 823                 // select us.\r
 824                 if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
 825                 {\r
 826                         enter_SelectionPhase();\r
 827                 }\r
 828                 else if (!SCSI_ReadFilt(SCSI_Filt_BSY))\r
 829                 {\r
 830                         scsiDev.phase = BUS_FREE;\r
 831                 }\r
 832         break;\r
 833 \r
 834         case ARBITRATION:\r
 835                 // TODO Support reselection.\r
 836                 break;\r
 837 \r
 838         case SELECTION:\r
 839                 process_SelectionPhase();\r
 840         break;\r
 841 \r
 842         case RESELECTION:\r
 843                 // Not currently supported!\r
 844         break;\r
 845 \r
 846         case COMMAND:\r
 847                 // Do not check ATN here. SCSI 1 & 2 initiators must set ATN\r
 848                 // and SEL together upon entering the selection phase if they\r
 849                 // want to send a message (IDENTIFY) immediately.\r
 850                 if (scsiDev.atnFlag)\r
 851                 {\r
 852                         process_MessageOut();\r
 853                 }\r
 854                 else\r
 855                 {\r
 856                         process_Command();\r
 857                 }\r
 858         break;\r
 859 \r
 860         case DATA_IN:\r
 861                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 862                 if (scsiDev.atnFlag)\r
 863                 {\r
 864                         process_MessageOut();\r
 865                 }\r
 866                 else\r
 867                 {\r
 868                         process_DataIn();\r
 869                 }\r
 870         break;\r
 871 \r
 872         case DATA_OUT:\r
 873                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 874                 if (scsiDev.atnFlag)\r
 875                 {\r
 876                         process_MessageOut();\r
 877                 }\r
 878                 else\r
 879                 {\r
 880                         process_DataOut();\r
 881                 }\r
 882         break;\r
 883 \r
 884         case STATUS:\r
 885                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 886                 if (scsiDev.atnFlag)\r
 887                 {\r
 888                         process_MessageOut();\r
 889                 }\r
 890                 else\r
 891                 {\r
 892                         process_Status();\r
 893                 }\r
 894         break;\r
 895 \r
 896         case MESSAGE_IN:\r
 897                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
 898                 if (scsiDev.atnFlag)\r
 899                 {\r
 900                         process_MessageOut();\r
 901                 }\r
 902                 else\r
 903                 {\r
 904                         process_MessageIn();\r
 905                 }\r
 906 \r
 907         break;\r
 908 \r
 909         case MESSAGE_OUT:\r
 910                 process_MessageOut();\r
 911         break;\r
 912         }\r
 913 }\r
 914 \r
 915 void scsiInit()\r
 916 {\r
 917         scsiDev.atnFlag = 0;\r
 918         scsiDev.resetFlag = 1;\r
 919         scsiDev.phase = BUS_FREE;\r
 920         scsiDev.target = NULL;\r
 921         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 922 \r
 923         int i;\r
 924         for (i = 0; i < MAX_SCSI_TARGETS; ++i)\r
 925         {\r
 926                 const TargetConfig* cfg = getConfigByIndex(i);\r
 927                 if (cfg && (cfg->scsiId & CONFIG_TARGET_ENABLED))\r
 928                 {\r
 929                         scsiDev.targets[i].targetId = cfg->scsiId & CONFIG_TARGET_ID_BITS;\r
 930                         scsiDev.targets[i].cfg = cfg;\r
 931 \r
 932                         scsiDev.targets[i].liveCfg.bytesPerSector = cfg->bytesPerSector;\r
 933                 }\r
 934                 else\r
 935                 {\r
 936                         scsiDev.targets[i].targetId = 0xff;\r
 937                         scsiDev.targets[i].cfg = NULL;\r
 938                 }\r
 939                 scsiDev.targets[i].reservedId = -1;\r
 940                 scsiDev.targets[i].reserverId = -1;\r
 941                 scsiDev.targets[i].unitAttention = POWER_ON_RESET;\r
 942                 scsiDev.targets[i].sense.code = NO_SENSE;\r
 943                 scsiDev.targets[i].sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 944         }\r
 945 }\r
 946 \r
 947 void scsiDisconnect()\r
 948 {\r
 949         scsiEnterPhase(MESSAGE_IN);\r
 950         scsiWriteByte(0x02); // save data pointer\r
 951         scsiWriteByte(0x04); // disconnect msg.\r
 952 \r
 953         // For now, the caller is responsible for tracking the disconnected\r
 954         // state, and calling scsiReconnect.\r
 955         // Ideally the client would exit their loop and we'd implement this\r
 956         // as part of scsiPoll\r
 957         int phase = scsiDev.phase;\r
 958         enter_BusFree();\r
 959         scsiDev.phase = phase;\r
 960 }\r
 961 \r
 962 int scsiReconnect()\r
 963 {\r
 964         int reconnected = 0;\r
 965 \r
 966         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 967         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 968         if (!sel && !bsy)\r
 969         {\r
 970                 CyDelayUs(1);\r
 971                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 972                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
 973         }\r
 974 \r
 975         if (!sel && !bsy)\r
 976         {\r
 977                 // Arbitrate.\r
 978                 ledOn();\r
 979                 uint8_t scsiIdMask = 1 << scsiDev.target->targetId;\r
 980                 SCSI_Out_Bits_Write(scsiIdMask);\r
 981                 SCSI_Out_Ctl_Write(1); // Write bits manually.\r
 982                 SCSI_SetPin(SCSI_Out_BSY);\r
 983 \r
 984                 CyDelayUs(3); // arbitrate delay. 2.4us.\r
 985 \r
 986                 uint8_t dbx = scsiReadDBxPins();\r
 987                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
 988                 if (sel || ((dbx ^ scsiIdMask) > scsiIdMask))\r
 989                 {\r
 990                         // Lost arbitration.\r
 991                         SCSI_Out_Ctl_Write(0);\r
 992                         SCSI_ClearPin(SCSI_Out_BSY);\r
 993                         ledOff();\r
 994                 }\r
 995                 else\r
 996                 {\r
 997                         // Won arbitration\r
 998                         SCSI_SetPin(SCSI_Out_SEL);\r
 999                         CyDelayUs(1); // Bus clear + Bus settle.\r
1000 \r
1001                         // Reselection phase\r
1002                         SCSI_CTL_PHASE_Write(__scsiphase_io);\r
1003                         SCSI_Out_Bits_Write(scsiIdMask | (1 << scsiDev.initiatorId));\r
1004                         scsiDeskewDelay(); // 2 deskew delays\r
1005                         scsiDeskewDelay(); // 2 deskew delays\r
1006                         SCSI_ClearPin(SCSI_Out_BSY);\r
1007                         CyDelayUs(1);  // Bus Settle Delay\r
1008 \r
1009                         uint32_t waitStart_ms = getTime_ms();\r
1010                         bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1011                         // Wait for initiator.\r
1012                         while (\r
1013                                 !bsy &&\r
1014                                 !scsiDev.resetFlag &&\r
1015                                 (elapsedTime_ms(waitStart_ms) < 250))\r
1016                         {\r
1017                                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1018                         }\r
1019 \r
1020                         if (bsy)\r
1021                         {\r
1022                                 SCSI_SetPin(SCSI_Out_BSY);\r
1023                                 scsiDeskewDelay(); // 2 deskew delays\r
1024                                 scsiDeskewDelay(); // 2 deskew delays\r
1025                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1026 \r
1027                                 // Prepare for the initial IDENTIFY message.\r
1028                                 SCSI_Out_Ctl_Write(0);\r
1029                                 scsiEnterPhase(MESSAGE_IN);\r
1030 \r
1031                                 // Send identify command\r
1032                                 scsiWriteByte(0x80);\r
1033 \r
1034                                 scsiEnterPhase(scsiDev.phase);\r
1035                                 reconnected = 1;\r
1036                         }\r
1037                         else\r
1038                         {\r
1039                                 // reselect timeout.\r
1040                                 SCSI_Out_Ctl_Write(0);\r
1041                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1042                                 SCSI_CTL_PHASE_Write(0);\r
1043                                 ledOff();\r
1044                         }\r
1045                 }\r
1046         }\r
1047         return reconnected;\r
1048 }\r
1049 \r
1050 #pragma GCC pop_options\r