src/firmware/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 \r
  18 #include "scsi.h"\r
  19 #include "scsiPhy.h"\r
  20 #include "config.h"\r
  21 #include "diagnostic.h"\r
  22 #include "disk.h"\r
  23 #include "inquiry.h"\r
  24 #include "led.h"\r
  25 #include "mode.h"\r
  26 #include "time.h"\r
  27 #include "bsp.h"\r
  28 #include "cdrom.h"\r
  29 //#include "debug.h"\r
  30 #include "tape.h"\r
  31 #include "mo.h"\r
  32 \r
  33 #include <string.h>\r
  34 \r
  35 // Global SCSI device state.\r
  36 ScsiDevice scsiDev S2S_DMA_ALIGN;\r
  37 \r
  38 static void enter_SelectionPhase(void);\r
  39 static void process_SelectionPhase(void);\r
  40 static void enter_BusFree(void);\r
  41 static void enter_MessageIn(uint8_t message);\r
  42 static void enter_Status(uint8_t status);\r
  43 static void enter_DataIn(int len);\r
  44 static void process_DataIn(void);\r
  45 static void process_DataOut(void);\r
  46 static void process_Command(void);\r
  47 \r
  48 static void doReserveRelease(void);\r
  49 \r
  50 static void enter_BusFree()\r
  51 {\r
  52         // This delay probably isn't needed for most SCSI hosts, but it won't\r
  53         // hurt either. It's possible some of the samplers needed this delay.\r
  54         if (scsiDev.compatMode < COMPAT_SCSI2)\r
  55         {\r
  56                 s2s_delay_us(2);\r
  57         }\r
  58 \r
  59 #if 0\r
  60         if (scsiDev.status != GOOD && isDebugEnabled())\r
  61         {\r
  62                 // We want to capture debug information for failure cases.\r
  63                 s2s_delay_ms(64);\r
  64         }\r
  65 #endif\r
  66 \r
  67         scsiEnterBusFree();\r
  68 \r
  69         // Wait for the initiator to cease driving signals\r
  70         // Bus settle delay + bus clear delay = 1200ns\r
  71         s2s_delay_us(2);\r
  72 \r
  73 \r
  74         s2s_ledOff();\r
  75         scsiDev.phase = BUS_FREE;\r
  76 }\r
  77 \r
  78 static void enter_MessageIn(uint8_t message)\r
  79 {\r
  80         scsiDev.msgIn = message;\r
  81         scsiDev.phase = MESSAGE_IN;\r
  82 }\r
  83 \r
  84 void process_MessageIn()\r
  85 {\r
  86         scsiEnterPhase(MESSAGE_IN);\r
  87         scsiWriteByte(scsiDev.msgIn);\r
  88 \r
  89         if (unlikely(scsiDev.atnFlag))\r
  90         {\r
  91                 // If there was a parity error, we go\r
  92                 // back to MESSAGE_OUT first, get out parity error message, then come\r
  93                 // back here.\r
  94         }\r
  95         else if ((scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE) ||\r
  96                 (scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG))\r
  97         {\r
  98                 // Go back to the command phase and start again.\r
  99                 scsiDev.phase = COMMAND;\r
 100                 scsiDev.dataPtr = 0;\r
 101                 scsiDev.savedDataPtr = 0;\r
 102                 scsiDev.dataLen = 0;\r
 103                 scsiDev.status = GOOD;\r
 104                 transfer.blocks = 0;\r
 105                 transfer.currentBlock = 0;\r
 106         }\r
 107         else /*if (scsiDev.msgIn == MSG_COMMAND_COMPLETE)*/\r
 108         {\r
 109                 enter_BusFree();\r
 110         }\r
 111 }\r
 112 \r
 113 static void messageReject()\r
 114 {\r
 115         scsiEnterPhase(MESSAGE_IN);\r
 116         scsiWriteByte(MSG_REJECT);\r
 117 }\r
 118 \r
 119 static void enter_Status(uint8_t status)\r
 120 {\r
 121         scsiDev.status = status;\r
 122         scsiDev.phase = STATUS;\r
 123 \r
 124         scsiDev.lastStatus = scsiDev.status;\r
 125         scsiDev.lastSense = scsiDev.target->sense.code;\r
 126         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 127 }\r
 128 \r
 129 void process_Status()\r
 130 {\r
 131         scsiEnterPhase(STATUS);\r
 132 \r
 133         uint8_t message;\r
 134 \r
 135         uint8_t control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 136         if ((scsiDev.status == GOOD) && (control & 0x01))\r
 137         {\r
 138                 // Linked command.\r
 139                 scsiDev.status = INTERMEDIATE;\r
 140                 if (control & 0x02)\r
 141                 {\r
 142                         message = MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG;\r
 143                 }\r
 144                 else\r
 145                 {\r
 146                         message = MSG_LINKED_COMMAND_COMPLETE;\r
 147                 }\r
 148         }\r
 149         else\r
 150         {\r
 151                 message = MSG_COMMAND_COMPLETE;\r
 152         }\r
 153         scsiWriteByte(scsiDev.status);\r
 154 \r
 155         scsiDev.lastStatus = scsiDev.status;\r
 156         scsiDev.lastSense = scsiDev.target->sense.code;\r
 157         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 158 \r
 159         // Command Complete occurs AFTER a valid status has been\r
 160         // sent. then we go bus-free.\r
 161         enter_MessageIn(message);\r
 162 }\r
 163 \r
 164 static void enter_DataIn(int len)\r
 165 {\r
 166         scsiDev.dataLen = len;\r
 167         scsiDev.phase = DATA_IN;\r
 168 }\r
 169 \r
 170 static void process_DataIn()\r
 171 {\r
 172         uint32_t len;\r
 173 \r
 174         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 175         {\r
 176                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 177         }\r
 178 \r
 179         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 180         if (len > 0)\r
 181         {\r
 182                 scsiEnterPhase(DATA_IN);\r
 183                 scsiWrite(scsiDev.data + scsiDev.dataPtr, len);\r
 184                 scsiDev.dataPtr += len;\r
 185         }\r
 186 \r
 187         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 188                 (transfer.currentBlock == transfer.blocks))\r
 189         {\r
 190                 enter_Status(GOOD);\r
 191         }\r
 192 }\r
 193 \r
 194 static void process_DataOut()\r
 195 {\r
 196         uint32_t len;\r
 197 \r
 198         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 199         {\r
 200                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 201         }\r
 202 \r
 203         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 204         if (len > 0)\r
 205         {\r
 206                 scsiEnterPhase(DATA_OUT);\r
 207 \r
 208                 int parityError = 0;\r
 209                 scsiRead(scsiDev.data + scsiDev.dataPtr, len, &parityError);\r
 210                 scsiDev.dataPtr += len;\r
 211 \r
 212                 if (parityError &&\r
 213                         (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 214                 {\r
 215                         scsiDev.target->sense.code = ABORTED_COMMAND;\r
 216                         scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 217                         enter_Status(CHECK_CONDITION);\r
 218                 }\r
 219         }\r
 220 \r
 221         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 222                 (transfer.currentBlock == transfer.blocks))\r
 223         {\r
 224                 if (scsiDev.postDataOutHook != NULL)\r
 225                 {\r
 226                         scsiDev.postDataOutHook();\r
 227                 }\r
 228                 else\r
 229                 {\r
 230                         enter_Status(GOOD);\r
 231                 }\r
 232         }\r
 233 }\r
 234 \r
 235 static const uint8_t CmdGroupBytes[8] = {6, 10, 10, 6, 6, 12, 6, 6};\r
 236 static void process_Command()\r
 237 {\r
 238         int group;\r
 239         uint8_t command;\r
 240         uint8_t control;\r
 241 \r
 242         scsiEnterPhase(COMMAND);\r
 243 \r
 244         memset(scsiDev.cdb + 6, 0, sizeof(scsiDev.cdb) - 6);\r
 245         int parityError = 0;\r
 246         scsiRead(scsiDev.cdb, 6, &parityError);\r
 247 \r
 248         group = scsiDev.cdb[0] >> 5;\r
 249         scsiDev.cdbLen = CmdGroupBytes[group];\r
 250         if (parityError &&\r
 251                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 252         {\r
 253                 // Don't try and read more bytes, as we cannot be sure what group\r
 254                 // the command should be.\r
 255         }\r
 256         else if (scsiDev.cdbLen - 6 > 0)\r
 257         {\r
 258                 scsiRead(scsiDev.cdb + 6, scsiDev.cdbLen - 6, &parityError);\r
 259         }\r
 260 \r
 261         command = scsiDev.cdb[0];\r
 262 \r
 263         // Prefer LUN's set by IDENTIFY messages for newer hosts.\r
 264         if (scsiDev.lun < 0)\r
 265         {\r
 266                 scsiDev.lun = scsiDev.cdb[1] >> 5;\r
 267         }\r
 268 \r
 269         control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 270 \r
 271         scsiDev.cmdCount++;\r
 272         const S2S_TargetCfg* cfg = scsiDev.target->cfg;\r
 273 \r
 274         if (unlikely(scsiDev.resetFlag))\r
 275         {\r
 276                 // Don't log bogus commands\r
 277                 scsiDev.cmdCount--;\r
 278                 memset(scsiDev.cdb, 0xff, sizeof(scsiDev.cdb));\r
 279                 return;\r
 280         }\r
 281         else if (parityError &&\r
 282                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 283         {\r
 284                 scsiDev.target->sense.code = ABORTED_COMMAND;\r
 285                 scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 286                 enter_Status(CHECK_CONDITION);\r
 287         }\r
 288         else if ((control & 0x02) && ((control & 0x01) == 0))\r
 289         {\r
 290                 // FLAG set without LINK flag.\r
 291                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 292                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 293                 enter_Status(CHECK_CONDITION);\r
 294         }\r
 295         else if (command == 0x12)\r
 296         {\r
 297                 s2s_scsiInquiry();\r
 298         }\r
 299         else if (command == 0x03)\r
 300         {\r
 301                 // REQUEST SENSE\r
 302                 uint32_t allocLength = scsiDev.cdb[4];\r
 303 \r
 304                 // As specified by the SASI and SCSI1 standard.\r
 305                 // Newer initiators won't be specifying 0 anyway.\r
 306                 if (allocLength == 0) allocLength = 4;\r
 307 \r
 308                 memset(scsiDev.data, 0, 256); // Max possible alloc length\r
 309                 scsiDev.data[0] = 0xF0;\r
 310                 scsiDev.data[2] = scsiDev.target->sense.code & 0x0F;\r
 311 \r
 312                 scsiDev.data[3] = transfer.lba >> 24;\r
 313                 scsiDev.data[4] = transfer.lba >> 16;\r
 314                 scsiDev.data[5] = transfer.lba >> 8;\r
 315                 scsiDev.data[6] = transfer.lba;\r
 316 \r
 317                 // Additional bytes if there are errors to report\r
 318                 scsiDev.data[7] = 10; // additional length\r
 319                 scsiDev.data[12] = scsiDev.target->sense.asc >> 8;\r
 320                 scsiDev.data[13] = scsiDev.target->sense.asc;\r
 321 \r
 322                 // Silently truncate results. SCSI-2 spec 8.2.14.\r
 323                 enter_DataIn(allocLength);\r
 324 \r
 325                 // This is a good time to clear out old sense information.\r
 326                 scsiDev.target->sense.code = NO_SENSE;\r
 327                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 328         }\r
 329         // Some old SCSI drivers do NOT properly support\r
 330         // unitAttention. eg. the Mac Plus would trigger a SCSI reset\r
 331         // on receiving the unit attention response on boot, thus\r
 332         // triggering another unit attention condition.\r
 333         else if (scsiDev.target->unitAttention &&\r
 334                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_UNIT_ATTENTION))\r
 335         {\r
 336                 scsiDev.target->sense.code = UNIT_ATTENTION;\r
 337                 scsiDev.target->sense.asc = scsiDev.target->unitAttention;\r
 338 \r
 339                 // If initiator doesn't do REQUEST SENSE for the next command, then\r
 340                 // data is lost.\r
 341                 scsiDev.target->unitAttention = 0;\r
 342 \r
 343                 enter_Status(CHECK_CONDITION);\r
 344         }\r
 345         else if (scsiDev.lun)\r
 346         {\r
 347                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 348                 scsiDev.target->sense.asc = LOGICAL_UNIT_NOT_SUPPORTED;\r
 349                 enter_Status(CHECK_CONDITION);\r
 350         }\r
 351         else if (command == 0x17 || command == 0x16)\r
 352         {\r
 353                 doReserveRelease();\r
 354         }\r
 355         else if ((scsiDev.target->reservedId >= 0) &&\r
 356                 (scsiDev.target->reservedId != scsiDev.initiatorId))\r
 357         {\r
 358                 enter_Status(CONFLICT);\r
 359         }\r
 360         // Handle odd device types first that may override basic read and\r
 361         // write commands. Will fall-through to generic disk handling.\r
 362         else if (((cfg->deviceType == S2S_CFG_OPTICAL) && scsiCDRomCommand()) ||\r
 363                 ((cfg->deviceType == S2S_CFG_SEQUENTIAL) && scsiTapeCommand()) ||\r
 364                 ((cfg->deviceType == S2S_CFG_MO) && scsiMOCommand()))\r
 365         {\r
 366                 // Already handled.\r
 367         }\r
 368         else if (scsiDiskCommand())\r
 369         {\r
 370                 // Already handled.\r
 371                 // check for the performance-critical read/write\r
 372                 // commands ASAP.\r
 373         }\r
 374         else if (command == 0x1C)\r
 375         {\r
 376                 scsiReceiveDiagnostic();\r
 377         }\r
 378         else if (command == 0x1D)\r
 379         {\r
 380                 scsiSendDiagnostic();\r
 381         }\r
 382         else if (command == 0x3B)\r
 383         {\r
 384                 scsiWriteBuffer();\r
 385         }\r
 386         else if (command == 0x3C)\r
 387         {\r
 388                 scsiReadBuffer();\r
 389         }\r
 390         else if (!scsiModeCommand())\r
 391         {\r
 392                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 393                 scsiDev.target->sense.asc = INVALID_COMMAND_OPERATION_CODE;\r
 394                 enter_Status(CHECK_CONDITION);\r
 395         }\r
 396 \r
 397         // Successful\r
 398         if (scsiDev.phase == COMMAND) // No status set, and not in DATA_IN\r
 399         {\r
 400                 enter_Status(GOOD);\r
 401         }\r
 402 \r
 403 }\r
 404 \r
 405 static void doReserveRelease()\r
 406 {\r
 407         int extentReservation = scsiDev.cdb[1] & 1;\r
 408         int thirdPty = scsiDev.cdb[1] & 0x10;\r
 409         int thirdPtyId = (scsiDev.cdb[1] >> 1) & 0x7;\r
 410         uint8_t command = scsiDev.cdb[0];\r
 411 \r
 412         int canRelease =\r
 413                 (!thirdPty && (scsiDev.initiatorId == scsiDev.target->reservedId)) ||\r
 414                         (thirdPty &&\r
 415                                 (scsiDev.target->reserverId == scsiDev.initiatorId) &&\r
 416                                 (scsiDev.target->reservedId == thirdPtyId)\r
 417                         );\r
 418 \r
 419         if (extentReservation)\r
 420         {\r
 421                 // Not supported.\r
 422                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 423                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 424                 enter_Status(CHECK_CONDITION);\r
 425         }\r
 426         else if (command == 0x17) // release\r
 427         {\r
 428                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 429                 {\r
 430                         scsiDev.target->reservedId = -1;\r
 431                         scsiDev.target->reserverId = -1;\r
 432                 }\r
 433                 else\r
 434                 {\r
 435                         enter_Status(CONFLICT);\r
 436                 }\r
 437         }\r
 438         else // assume reserve.\r
 439         {\r
 440                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 441                 {\r
 442                         scsiDev.target->reserverId = scsiDev.initiatorId;\r
 443                         if (thirdPty)\r
 444                         {\r
 445                                 scsiDev.target->reservedId = thirdPtyId;\r
 446                         }\r
 447                         else\r
 448                         {\r
 449                                 scsiDev.target->reservedId = scsiDev.initiatorId;\r
 450                         }\r
 451                 }\r
 452                 else\r
 453                 {\r
 454                         // Already reserved by someone else!\r
 455                         enter_Status(CONFLICT);\r
 456                 }\r
 457         }\r
 458 }\r
 459 \r
 460 static void scsiReset()\r
 461 {\r
 462         scsiDev.rstCount++;\r
 463         s2s_ledOff();\r
 464 \r
 465         scsiPhyReset();\r
 466 \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 \r
 486         for (int i = 0; i < S2S_MAX_TARGETS; ++i)\r
 487         {\r
 488                 scsiDev.target[i].syncOffset = 0;\r
 489                 scsiDev.target[i].syncPeriod = 0;\r
 490         }\r
 491 \r
 492         scsiDiskReset();\r
 493 \r
 494         scsiDev.postDataOutHook = NULL;\r
 495 \r
 496         // Sleep to allow the bus to settle down a bit.\r
 497         // We must be ready again within the "Reset to selection time" of\r
 498         // 250ms.\r
 499         // There is no guarantee that the RST line will be negated by then.\r
 500         // NOTE: We could be connected and powered by USB for configuration,\r
 501         // in which case TERMPWR cannot be supplied, and reset will ALWAYS\r
 502         // be true. Therefore, the sleep here must be slow to avoid slowing\r
 503         // USB comms\r
 504         s2s_delay_ms(1); // 1ms.\r
 505 }\r
 506 \r
 507 static void enter_SelectionPhase()\r
 508 {\r
 509         // Ignore stale versions of this flag, but ensure we know the\r
 510         // current value if the flag is still set.\r
 511         scsiDev.atnFlag = 0;\r
 512         scsiDev.dataPtr = 0;\r
 513         scsiDev.savedDataPtr = 0;\r
 514         scsiDev.dataLen = 0;\r
 515         scsiDev.status = GOOD;\r
 516         scsiDev.phase = SELECTION;\r
 517         scsiDev.lun = -1;\r
 518         scsiDev.discPriv = 0;\r
 519 \r
 520         scsiDev.initiatorId = -1;\r
 521         scsiDev.target = NULL;\r
 522 \r
 523         transfer.blocks = 0;\r
 524         transfer.currentBlock = 0;\r
 525 \r
 526         scsiDev.postDataOutHook = NULL;\r
 527 \r
 528         scsiDev.needSyncNegotiationAck = 0;\r
 529 }\r
 530 \r
 531 static void process_SelectionPhase()\r
 532 {\r
 533         // Selection delays.\r
 534         // Many SCSI1 samplers that use a 5380 chip need a delay of at least 1ms.\r
 535         // The Mac Plus boot-time (ie. rom code) selection abort time\r
 536         // is < 1ms and must have no delay (standard suggests 250ms abort time)\r
 537         // Most newer SCSI2 hosts don't care either way.\r
 538         if (scsiDev.boardCfg.selectionDelay == 255) // auto\r
 539         {\r
 540                 if (scsiDev.compatMode < COMPAT_SCSI2)\r
 541                 {\r
 542                         s2s_delay_ms(1);\r
 543                 }\r
 544         }\r
 545         else if (scsiDev.boardCfg.selectionDelay != 0)\r
 546         {\r
 547                 s2s_delay_ms(scsiDev.boardCfg.selectionDelay);\r
 548         }\r
 549 \r
 550         uint8_t selStatus = *SCSI_STS_SELECTED;\r
 551 \r
 552         int tgtIndex;\r
 553         TargetState* target = NULL;\r
 554         for (tgtIndex = 0; tgtIndex < S2S_MAX_TARGETS; ++tgtIndex)\r
 555         {\r
 556                 if (scsiDev.targets[tgtIndex].targetId == (selStatus & 7))\r
 557                 {\r
 558                         target = &scsiDev.targets[tgtIndex];\r
 559                         break;\r
 560                 }\r
 561         }\r
 562         if ((target != NULL) && (selStatus & 0x40))\r
 563         {\r
 564                 // We've been selected!\r
 565                 // Assert BSY - Selection success!\r
 566                 // must happen within 200us (Selection abort time) of seeing our\r
 567                 // ID + SEL.\r
 568                 // (Note: the initiator will be waiting the "Selection time-out delay"\r
 569                 // for our BSY response, which is actually a very generous 250ms)\r
 570                 *SCSI_CTRL_BSY = 1;\r
 571                 s2s_ledOn();\r
 572 \r
 573                 scsiDev.target = target;\r
 574 \r
 575                 // Do we enter MESSAGE OUT immediately ? SCSI 1 and 2 standards says\r
 576                 // move to MESSAGE OUT if ATN is true before we assert BSY.\r
 577                 // The initiator should assert ATN with SEL.\r
 578                 scsiDev.atnFlag = selStatus & 0x80;\r
 579 \r
 580 \r
 581                 // Unit attention breaks many older SCSI hosts. Disable it completely\r
 582                 // for SCSI-1 (and older) hosts, regardless of our configured setting.\r
 583                 // Enable the compatability mode also as many SASI and SCSI1\r
 584                 // controllers don't generate parity bits.\r
 585                 if (!scsiDev.atnFlag)\r
 586                 {\r
 587                         target->unitAttention = 0;\r
 588                         scsiDev.compatMode = COMPAT_SCSI1;\r
 589                 }\r
 590                 else if (!(scsiDev.boardCfg.flags & S2S_CFG_ENABLE_SCSI2))\r
 591                 {\r
 592                         scsiDev.compatMode = COMPAT_SCSI1;\r
 593                 }\r
 594                 else\r
 595                 {\r
 596                         scsiDev.compatMode = COMPAT_SCSI2;\r
 597                 }\r
 598 \r
 599                 scsiDev.selCount++;\r
 600 \r
 601 \r
 602                 // Save our initiator now that we're no longer in a time-critical\r
 603                 // section.\r
 604                 // SCSI1/SASI initiators may not set their own ID.\r
 605                 scsiDev.initiatorId = (selStatus >> 3) & 0x7;\r
 606 \r
 607                 while (likely(!scsiDev.resetFlag) && scsiStatusSEL())\r
 608                 {\r
 609                         // Wait until the end of the selection phase.\r
 610                 }\r
 611 \r
 612                 scsiDev.phase = COMMAND;\r
 613         }\r
 614         else if (!selStatus)\r
 615         {\r
 616                 scsiDev.phase = BUS_BUSY;\r
 617         }\r
 618 }\r
 619 \r
 620 static void process_MessageOut()\r
 621 {\r
 622         scsiEnterPhase(MESSAGE_OUT);\r
 623 \r
 624         scsiDev.atnFlag = 0;\r
 625         scsiDev.msgOut = scsiReadByte();\r
 626         scsiDev.msgCount++;\r
 627 \r
 628         if (scsiParityError() &&\r
 629                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 630         {\r
 631                 // Skip the remaining message bytes, and then start the MESSAGE_OUT\r
 632                 // phase again from the start. The initiator will re-send the\r
 633                 // same set of messages.\r
 634                 while (scsiStatusATN() && !scsiDev.resetFlag)\r
 635                 {\r
 636                         scsiReadByte();\r
 637                 }\r
 638 \r
 639                 // Go-back and try the message again.\r
 640                 scsiDev.atnFlag = 1;\r
 641         }\r
 642         else if (scsiDev.msgOut == 0x00)\r
 643         {\r
 644                 // COMMAND COMPLETE. but why would the target be receiving this ? nfi.\r
 645                 enter_BusFree();\r
 646         }\r
 647         else if (scsiDev.msgOut == 0x06)\r
 648         {\r
 649                 // ABORT\r
 650                 scsiDiskReset();\r
 651                 enter_BusFree();\r
 652         }\r
 653         else if (scsiDev.msgOut == 0x0C)\r
 654         {\r
 655                 // BUS DEVICE RESET\r
 656 \r
 657                 scsiDiskReset();\r
 658 \r
 659                 scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 660 \r
 661                 // ANY initiator can reset the reservation state via this message.\r
 662                 scsiDev.target->reservedId = -1;\r
 663                 scsiDev.target->reserverId = -1;\r
 664 \r
 665                 // Cancel any sync negotiation\r
 666                 scsiDev.target->syncOffset = 0;\r
 667                 scsiDev.target->syncPeriod = 0;\r
 668 \r
 669                 enter_BusFree();\r
 670         }\r
 671         else if (scsiDev.msgOut == 0x05)\r
 672         {\r
 673                 // Initiate Detected Error\r
 674                 // Ignore for now\r
 675         }\r
 676         else if (scsiDev.msgOut == 0x0F)\r
 677         {\r
 678                 // INITIATE RECOVERY\r
 679                 // Ignore for now\r
 680         }\r
 681         else if (scsiDev.msgOut == 0x10)\r
 682         {\r
 683                 // RELEASE RECOVERY\r
 684                 // Ignore for now\r
 685                 enter_BusFree();\r
 686         }\r
 687         else if (scsiDev.msgOut == MSG_REJECT)\r
 688         {\r
 689                 // Message Reject\r
 690                 // Oh well.\r
 691 \r
 692                 if (scsiDev.needSyncNegotiationAck)\r
 693                 {\r
 694                         scsiDev.target->syncOffset = 0;\r
 695                         scsiDev.target->syncPeriod = 0;\r
 696                         scsiDev.needSyncNegotiationAck = 0;\r
 697                 }\r
 698         }\r
 699         else if (scsiDev.msgOut == 0x08)\r
 700         {\r
 701                 // NOP\r
 702         }\r
 703         else if (scsiDev.msgOut == 0x09)\r
 704         {\r
 705                 // Message Parity Error\r
 706                 // Go back and re-send the last message.\r
 707                 scsiDev.phase = MESSAGE_IN;\r
 708         }\r
 709         else if (scsiDev.msgOut & 0x80) // 0x80 -> 0xFF\r
 710         {\r
 711                 // IDENTIFY\r
 712                 if ((scsiDev.msgOut & 0x18) || // Reserved bits set.\r
 713                         (scsiDev.msgOut & 0x20))  // We don't have any target routines!\r
 714                 {\r
 715                         messageReject();\r
 716                 }\r
 717 \r
 718                 scsiDev.lun = scsiDev.msgOut & 0x7;\r
 719                 scsiDev.discPriv = \r
 720                         ((scsiDev.msgOut & 0x40) && (scsiDev.initiatorId >= 0))\r
 721                                 ? 1 : 0;\r
 722         }\r
 723         else if (scsiDev.msgOut >= 0x20 && scsiDev.msgOut <= 0x2F)\r
 724         {\r
 725                 // Two byte message. We don't support these. read and discard.\r
 726                 scsiReadByte();\r
 727 \r
 728                 if (scsiDev.msgOut == 0x23) {\r
 729                         // Ignore Wide Residue. We're only 8 bit anyway.\r
 730                 } else {\r
 731                         messageReject();\r
 732                 }\r
 733         }\r
 734         else if (scsiDev.msgOut == 0x01)\r
 735         {\r
 736                 int i;\r
 737 \r
 738                 // Extended message.\r
 739                 int msgLen = scsiReadByte();\r
 740                 if (msgLen == 0) msgLen = 256;\r
 741                 uint8_t extmsg[256];\r
 742                 for (i = 0; i < msgLen && !scsiDev.resetFlag; ++i)\r
 743                 {\r
 744                         // Discard bytes.\r
 745                         extmsg[i] = scsiReadByte();\r
 746                 }\r
 747 \r
 748                 if (extmsg[0] == 3 && msgLen == 2) // Wide Data Request\r
 749                 {\r
 750                         // Negotiate down to 8bit\r
 751                         scsiEnterPhase(MESSAGE_IN);\r
 752                         static const uint8_t WDTR[] = {0x01, 0x02, 0x03, 0x00};\r
 753                         scsiWrite(WDTR, sizeof(WDTR));\r
 754                 }\r
 755                 else if (extmsg[0] == 1 && msgLen == 3) // Synchronous data request\r
 756                 {\r
 757                         int transferPeriod = extmsg[1];\r
 758                         int offset = extmsg[2];\r
 759 \r
 760                         if ((scsiDev.compatMode < COMPAT_SCSI2) ||\r
 761                                 (transferPeriod > 50)) // 200ns, 5MB/s\r
 762                         {\r
 763                                 scsiDev.target->syncOffset = 0;\r
 764                                 scsiDev.target->syncPeriod = 0;\r
 765                         } else {\r
 766                                 scsiDev.target->syncOffset = offset < 15 ? offset : 15;\r
 767                                 // FAST20 / 50ns / 20MHz is disabled for now due to\r
 768                                 // data corruption while reading data. We can count the\r
 769                                 // ACK's correctly, but can't save the data to a register\r
 770                                 // before it changes.\r
 771                                 // TODO work out the fastest sync period that will work\r
 772                                 /*\r
 773                                 if (transferPeriod <= 12)\r
 774                                 {\r
 775                                         scsiDev.target->syncPeriod = 12; // 50ns, 20MB/s\r
 776                                 }\r
 777                                 else */if (transferPeriod <= 25)\r
 778                                 {\r
 779                                         scsiDev.target->syncPeriod = 25; // 100ns, 10MB/s\r
 780                                 } else {\r
 781                                         scsiDev.target->syncPeriod = 50; // 200ns, 5MB/s\r
 782                                 }\r
 783                         }\r
 784 \r
 785                         scsiEnterPhase(MESSAGE_IN);\r
 786                         uint8_t SDTR[] = {0x01, 0x03, 0x01, scsiDev.target->syncPeriod, scsiDev.target->syncOffset};\r
 787                         scsiWrite(SDTR, sizeof(SDTR));\r
 788                         scsiDev.needSyncNegotiationAck = 1; // Check if this message is rejected.\r
 789                 }\r
 790                 else\r
 791                 {\r
 792                         // Not supported\r
 793                         messageReject();\r
 794                 }\r
 795         }\r
 796         else\r
 797         {\r
 798                 messageReject();\r
 799         }\r
 800 \r
 801         // Re-check the ATN flag in case it stays asserted.\r
 802         scsiDev.atnFlag |= scsiStatusATN();\r
 803 \r
 804         if (!scsiDev.atnFlag)\r
 805         {\r
 806                 // Message wasn't rejected!\r
 807                 scsiDev.needSyncNegotiationAck = 0;\r
 808         }\r
 809 }\r
 810 \r
 811 void scsiPoll(void)\r
 812 {\r
 813         if (unlikely(scsiDev.resetFlag))\r
 814         {\r
 815                 scsiReset();\r
 816                 if ((scsiDev.resetFlag = scsiStatusRST()))\r
 817                 {\r
 818                         // Still in reset phase. Do not try and process any commands.\r
 819                         return;\r
 820                 }\r
 821         }\r
 822 \r
 823         switch (scsiDev.phase)\r
 824         {\r
 825         case BUS_FREE:\r
 826                 if (scsiStatusBSY())\r
 827                 {\r
 828                         scsiDev.phase = BUS_BUSY;\r
 829                 }\r
 830                 // The Arbitration phase is optional for SCSI1/SASI hosts if there is only\r
 831                 // one initiator in the chain. Support this by moving\r
 832                 // straight to selection if SEL is asserted.\r
 833                 // ie. the initiator won't assert BSY and it's own ID before moving to selection.\r
 834                 else if (*SCSI_STS_SELECTED)\r
 835                 {\r
 836                         enter_SelectionPhase();\r
 837                 }\r
 838         break;\r
 839 \r
 840         case BUS_BUSY:\r
 841                 // Someone is using the bus. Perhaps they are trying to\r
 842                 // select us.\r
 843                 if (*SCSI_STS_SELECTED)\r
 844                 {\r
 845                         enter_SelectionPhase();\r
 846                 }\r
 847                 else if (!scsiStatusBSY())\r
 848                 {\r
 849                         scsiDev.phase = BUS_FREE;\r
 850                 }\r
 851         break;\r
 852 \r
 853         case ARBITRATION:\r
 854                 // TODO Support reselection.\r
 855                 break;\r
 856 \r
 857         case SELECTION:\r
 858                 process_SelectionPhase();\r
 859         break;\r
 860 \r
 861         case RESELECTION:\r
 862                 // Not currently supported!\r
 863         break;\r
 864 \r
 865         case COMMAND:\r
 866                 // Do not check ATN here. SCSI 1 & 2 initiators must set ATN\r
 867                 // and SEL together upon entering the selection phase if they\r
 868                 // want to send a message (IDENTIFY) immediately.\r
 869                 if (scsiDev.atnFlag)\r
 870                 {\r
 871                         process_MessageOut();\r
 872                 }\r
 873                 else\r
 874                 {\r
 875                         process_Command();\r
 876                 }\r
 877         break;\r
 878 \r
 879         case DATA_IN:\r
 880                 scsiDev.atnFlag |= scsiStatusATN();\r
 881                 if (scsiDev.atnFlag)\r
 882                 {\r
 883                         process_MessageOut();\r
 884                 }\r
 885                 else\r
 886                 {\r
 887                         process_DataIn();\r
 888                 }\r
 889         break;\r
 890 \r
 891         case DATA_OUT:\r
 892                 scsiDev.atnFlag |= scsiStatusATN();\r
 893                 if (scsiDev.atnFlag)\r
 894                 {\r
 895                         process_MessageOut();\r
 896                 }\r
 897                 else\r
 898                 {\r
 899                         process_DataOut();\r
 900                 }\r
 901         break;\r
 902 \r
 903         case STATUS:\r
 904                 scsiDev.atnFlag |= scsiStatusATN();\r
 905                 if (scsiDev.atnFlag)\r
 906                 {\r
 907                         process_MessageOut();\r
 908                 }\r
 909                 else\r
 910                 {\r
 911                         process_Status();\r
 912                 }\r
 913         break;\r
 914 \r
 915         case MESSAGE_IN:\r
 916                 scsiDev.atnFlag |= scsiStatusATN();\r
 917                 if (scsiDev.atnFlag)\r
 918                 {\r
 919                         process_MessageOut();\r
 920                 }\r
 921                 else\r
 922                 {\r
 923                         process_MessageIn();\r
 924                 }\r
 925 \r
 926         break;\r
 927 \r
 928         case MESSAGE_OUT:\r
 929                 process_MessageOut();\r
 930         break;\r
 931         }\r
 932 }\r
 933 \r
 934 void scsiInit()\r
 935 {\r
 936         static int firstInit = 1;\r
 937 \r
 938         scsiDev.atnFlag = 0;\r
 939         scsiDev.resetFlag = 1;\r
 940         scsiDev.phase = BUS_FREE;\r
 941         scsiDev.target = NULL;\r
 942         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 943 \r
 944         int i;\r
 945         for (i = 0; i < S2S_MAX_TARGETS; ++i)\r
 946         {\r
 947                 const S2S_TargetCfg* cfg = s2s_getConfigByIndex(i);\r
 948                 if (cfg && (cfg->scsiId & S2S_CFG_TARGET_ENABLED))\r
 949                 {\r
 950                         scsiDev.targets[i].targetId = cfg->scsiId & S2S_CFG_TARGET_ID_BITS;\r
 951                         scsiDev.targets[i].cfg = cfg;\r
 952 \r
 953                         scsiDev.targets[i].liveCfg.bytesPerSector = cfg->bytesPerSector;\r
 954                 }\r
 955                 else\r
 956                 {\r
 957                         scsiDev.targets[i].targetId = 0xff;\r
 958                         scsiDev.targets[i].cfg = NULL;\r
 959                 }\r
 960                 scsiDev.targets[i].reservedId = -1;\r
 961                 scsiDev.targets[i].reserverId = -1;\r
 962                 if (firstInit)\r
 963                 {\r
 964                         scsiDev.targets[i].unitAttention = POWER_ON_RESET;\r
 965                 }\r
 966                 else\r
 967                 {\r
 968                         scsiDev.targets[i].unitAttention = PARAMETERS_CHANGED;\r
 969                 }\r
 970                 scsiDev.targets[i].sense.code = NO_SENSE;\r
 971                 scsiDev.targets[i].sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 972 \r
 973                 scsiDev.targets[i].syncOffset = 0;\r
 974                 scsiDev.targets[i].syncPeriod = 0;\r
 975         }\r
 976         firstInit = 0;\r
 977 }\r
 978 \r
 979 /* TODO REENABLE\r
 980 void scsiDisconnect()\r
 981 {\r
 982         scsiEnterPhase(MESSAGE_IN);\r
 983         scsiWriteByte(0x02); // save data pointer\r
 984         scsiWriteByte(0x04); // disconnect msg.\r
 985 \r
 986         // For now, the caller is responsible for tracking the disconnected\r
 987         // state, and calling scsiReconnect.\r
 988         // Ideally the client would exit their loop and we'd implement this\r
 989         // as part of scsiPoll\r
 990         int phase = scsiDev.phase;\r
 991         enter_BusFree();\r
 992         scsiDev.phase = phase;\r
 993 }\r
 994 */\r
 995 \r
 996 /* TODO REENABLE\r
 997 int scsiReconnect()\r
 998 {\r
 999         int reconnected = 0;\r
1000 \r
1001         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
1002         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1003         if (!sel && !bsy)\r
1004         {\r
1005                 s2s_delay_us(1);\r
1006                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
1007                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1008         }\r
1009 \r
1010         if (!sel && !bsy)\r
1011         {\r
1012                 // Arbitrate.\r
1013                 s2s_ledOn();\r
1014                 uint8_t scsiIdMask = 1 << scsiDev.target->targetId;\r
1015                 SCSI_Out_Bits_Write(scsiIdMask);\r
1016                 SCSI_Out_Ctl_Write(1); // Write bits manually.\r
1017                 SCSI_SetPin(SCSI_Out_BSY);\r
1018 \r
1019                 s2s_delay_us(3); // arbitrate delay. 2.4us.\r
1020 \r
1021                 uint8_t dbx = scsiReadDBxPins();\r
1022                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
1023                 if (sel || ((dbx ^ scsiIdMask) > scsiIdMask))\r
1024                 {\r
1025                         // Lost arbitration.\r
1026                         SCSI_Out_Ctl_Write(0);\r
1027                         SCSI_ClearPin(SCSI_Out_BSY);\r
1028                         s2s_ledOff();\r
1029                 }\r
1030                 else\r
1031                 {\r
1032                         // Won arbitration\r
1033                         SCSI_SetPin(SCSI_Out_SEL);\r
1034                         s2s_delay_us(1); // Bus clear + Bus settle.\r
1035 \r
1036                         // Reselection phase\r
1037                         SCSI_CTL_PHASE_Write(__scsiphase_io);\r
1038                         SCSI_Out_Bits_Write(scsiIdMask | (1 << scsiDev.initiatorId));\r
1039                         scsiDeskewDelay(); // 2 deskew delays\r
1040                         scsiDeskewDelay(); // 2 deskew delays\r
1041                         SCSI_ClearPin(SCSI_Out_BSY);\r
1042                         s2s_delay_us(1);  // Bus Settle Delay\r
1043 \r
1044                         uint32_t waitStart_ms = getTime_ms();\r
1045                         bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1046                         // Wait for initiator.\r
1047                         while (\r
1048                                 !bsy &&\r
1049                                 !scsiDev.resetFlag &&\r
1050                                 (elapsedTime_ms(waitStart_ms) < 250))\r
1051                         {\r
1052                                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1053                         }\r
1054 \r
1055                         if (bsy)\r
1056                         {\r
1057                                 SCSI_SetPin(SCSI_Out_BSY);\r
1058                                 scsiDeskewDelay(); // 2 deskew delays\r
1059                                 scsiDeskewDelay(); // 2 deskew delays\r
1060                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1061 \r
1062                                 // Prepare for the initial IDENTIFY message.\r
1063                                 SCSI_Out_Ctl_Write(0);\r
1064                                 scsiEnterPhase(MESSAGE_IN);\r
1065 \r
1066                                 // Send identify command\r
1067                                 scsiWriteByte(0x80);\r
1068 \r
1069                                 scsiEnterPhase(scsiDev.phase);\r
1070                                 reconnected = 1;\r
1071                         }\r
1072                         else\r
1073                         {\r
1074                                 // reselect timeout.\r
1075                                 SCSI_Out_Ctl_Write(0);\r
1076                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1077                                 SCSI_CTL_PHASE_Write(0);\r
1078                                 s2s_ledOff();\r
1079                         }\r
1080                 }\r
1081         }\r
1082         return reconnected;\r
1083 }\r
1084 */\r
1085 \r