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         scsiDev.selFlag = 0;\r
  77 }\r
  78 \r
  79 static void enter_MessageIn(uint8_t 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.dataPtr = 0;\r
 102                 scsiDev.savedDataPtr = 0;\r
 103                 scsiDev.dataLen = 0;\r
 104                 scsiDev.status = GOOD;\r
 105                 transfer.blocks = 0;\r
 106                 transfer.currentBlock = 0;\r
 107         }\r
 108         else /*if (scsiDev.msgIn == MSG_COMMAND_COMPLETE)*/\r
 109         {\r
 110                 enter_BusFree();\r
 111         }\r
 112 }\r
 113 \r
 114 static void messageReject()\r
 115 {\r
 116         scsiEnterPhase(MESSAGE_IN);\r
 117         scsiWriteByte(MSG_REJECT);\r
 118 }\r
 119 \r
 120 static void enter_Status(uint8_t status)\r
 121 {\r
 122         scsiDev.status = status;\r
 123         scsiDev.phase = STATUS;\r
 124 \r
 125         scsiDev.lastStatus = scsiDev.status;\r
 126         scsiDev.lastSense = scsiDev.target->sense.code;\r
 127         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 128 }\r
 129 \r
 130 void process_Status()\r
 131 {\r
 132         scsiEnterPhase(STATUS);\r
 133 \r
 134         uint8_t message;\r
 135 \r
 136         uint8_t control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 137         if ((scsiDev.status == GOOD) && (control & 0x01))\r
 138         {\r
 139                 // Linked command.\r
 140                 scsiDev.status = INTERMEDIATE;\r
 141                 if (control & 0x02)\r
 142                 {\r
 143                         message = MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG;\r
 144                 }\r
 145                 else\r
 146                 {\r
 147                         message = MSG_LINKED_COMMAND_COMPLETE;\r
 148                 }\r
 149         }\r
 150         else\r
 151         {\r
 152                 message = MSG_COMMAND_COMPLETE;\r
 153         }\r
 154         scsiWriteByte(scsiDev.status);\r
 155 \r
 156         scsiDev.lastStatus = scsiDev.status;\r
 157         scsiDev.lastSense = scsiDev.target->sense.code;\r
 158         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
 159 \r
 160         // Command Complete occurs AFTER a valid status has been\r
 161         // sent. then we go bus-free.\r
 162         enter_MessageIn(message);\r
 163 }\r
 164 \r
 165 static void enter_DataIn(int len)\r
 166 {\r
 167         scsiDev.dataLen = len;\r
 168         scsiDev.phase = DATA_IN;\r
 169 }\r
 170 \r
 171 static void process_DataIn()\r
 172 {\r
 173         uint32_t len;\r
 174 \r
 175         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 176         {\r
 177                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 178         }\r
 179 \r
 180         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 181         if (len > 0)\r
 182         {\r
 183                 scsiEnterPhase(DATA_IN);\r
 184                 scsiWrite(scsiDev.data + scsiDev.dataPtr, len);\r
 185                 scsiDev.dataPtr += len;\r
 186         }\r
 187 \r
 188         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 189                 (transfer.currentBlock == transfer.blocks))\r
 190         {\r
 191                 enter_Status(GOOD);\r
 192         }\r
 193 }\r
 194 \r
 195 static void process_DataOut()\r
 196 {\r
 197         uint32_t len;\r
 198 \r
 199         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
 200         {\r
 201                 scsiDev.dataLen = sizeof(scsiDev.data);\r
 202         }\r
 203 \r
 204         len = scsiDev.dataLen - scsiDev.dataPtr;\r
 205         if (len > 0)\r
 206         {\r
 207                 scsiEnterPhase(DATA_OUT);\r
 208 \r
 209                 int parityError = 0;\r
 210                 scsiRead(scsiDev.data + scsiDev.dataPtr, len, &parityError);\r
 211                 scsiDev.dataPtr += len;\r
 212 \r
 213                 if (parityError &&\r
 214                         (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 215                 {\r
 216                         scsiDev.target->sense.code = ABORTED_COMMAND;\r
 217                         scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 218                         enter_Status(CHECK_CONDITION);\r
 219                 }\r
 220         }\r
 221 \r
 222         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
 223                 (transfer.currentBlock == transfer.blocks))\r
 224         {\r
 225                 if (scsiDev.postDataOutHook != NULL)\r
 226                 {\r
 227                         scsiDev.postDataOutHook();\r
 228                 }\r
 229                 else\r
 230                 {\r
 231                         enter_Status(GOOD);\r
 232                 }\r
 233         }\r
 234 }\r
 235 \r
 236 static const uint8_t CmdGroupBytes[8] = {6, 10, 10, 6, 6, 12, 6, 6};\r
 237 static void process_Command()\r
 238 {\r
 239         int group;\r
 240         uint8_t command;\r
 241         uint8_t control;\r
 242 \r
 243         scsiEnterPhase(COMMAND);\r
 244 \r
 245         memset(scsiDev.cdb + 6, 0, sizeof(scsiDev.cdb) - 6);\r
 246         int parityError = 0;\r
 247         scsiRead(scsiDev.cdb, 6, &parityError);\r
 248 \r
 249         group = scsiDev.cdb[0] >> 5;\r
 250         scsiDev.cdbLen = CmdGroupBytes[group];\r
 251         if (parityError &&\r
 252                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 253         {\r
 254                 // Don't try and read more bytes, as we cannot be sure what group\r
 255                 // the command should be.\r
 256         }\r
 257         else if (scsiDev.cdbLen - 6 > 0)\r
 258         {\r
 259                 scsiRead(scsiDev.cdb + 6, scsiDev.cdbLen - 6, &parityError);\r
 260         }\r
 261 \r
 262         command = scsiDev.cdb[0];\r
 263 \r
 264         // Prefer LUN's set by IDENTIFY messages for newer hosts.\r
 265         if (scsiDev.lun < 0)\r
 266         {\r
 267                 scsiDev.lun = scsiDev.cdb[1] >> 5;\r
 268         }\r
 269 \r
 270         control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
 271 \r
 272         scsiDev.cmdCount++;\r
 273         const S2S_TargetCfg* cfg = scsiDev.target->cfg;\r
 274 \r
 275         if (unlikely(scsiDev.resetFlag))\r
 276         {\r
 277                 // Don't log bogus commands\r
 278                 scsiDev.cmdCount--;\r
 279                 memset(scsiDev.cdb, 0xff, sizeof(scsiDev.cdb));\r
 280                 return;\r
 281         }\r
 282         else if (parityError &&\r
 283                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 284         {\r
 285                 scsiDev.target->sense.code = ABORTED_COMMAND;\r
 286                 scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
 287                 enter_Status(CHECK_CONDITION);\r
 288         }\r
 289         else if ((control & 0x02) && ((control & 0x01) == 0))\r
 290         {\r
 291                 // FLAG set without LINK flag.\r
 292                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 293                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 294                 enter_Status(CHECK_CONDITION);\r
 295         }\r
 296         else if (command == 0x12)\r
 297         {\r
 298                 s2s_scsiInquiry();\r
 299         }\r
 300         else if (command == 0x03)\r
 301         {\r
 302                 // REQUEST SENSE\r
 303                 uint32_t allocLength = scsiDev.cdb[4];\r
 304 \r
 305                 // As specified by the SASI and SCSI1 standard.\r
 306                 // Newer initiators won't be specifying 0 anyway.\r
 307                 if (allocLength == 0) allocLength = 4;\r
 308 \r
 309                 memset(scsiDev.data, 0, 256); // Max possible alloc length\r
 310                 scsiDev.data[0] = 0xF0;\r
 311                 scsiDev.data[2] = scsiDev.target->sense.code & 0x0F;\r
 312 \r
 313                 scsiDev.data[3] = transfer.lba >> 24;\r
 314                 scsiDev.data[4] = transfer.lba >> 16;\r
 315                 scsiDev.data[5] = transfer.lba >> 8;\r
 316                 scsiDev.data[6] = transfer.lba;\r
 317 \r
 318                 // Additional bytes if there are errors to report\r
 319                 scsiDev.data[7] = 10; // additional length\r
 320                 scsiDev.data[12] = scsiDev.target->sense.asc >> 8;\r
 321                 scsiDev.data[13] = scsiDev.target->sense.asc;\r
 322 \r
 323                 // Silently truncate results. SCSI-2 spec 8.2.14.\r
 324                 enter_DataIn(allocLength);\r
 325 \r
 326                 // This is a good time to clear out old sense information.\r
 327                 scsiDev.target->sense.code = NO_SENSE;\r
 328                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 329         }\r
 330         // Some old SCSI drivers do NOT properly support\r
 331         // unitAttention. eg. the Mac Plus would trigger a SCSI reset\r
 332         // on receiving the unit attention response on boot, thus\r
 333         // triggering another unit attention condition.\r
 334         else if (scsiDev.target->unitAttention &&\r
 335                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_UNIT_ATTENTION))\r
 336         {\r
 337                 scsiDev.target->sense.code = UNIT_ATTENTION;\r
 338                 scsiDev.target->sense.asc = scsiDev.target->unitAttention;\r
 339 \r
 340                 // If initiator doesn't do REQUEST SENSE for the next command, then\r
 341                 // data is lost.\r
 342                 scsiDev.target->unitAttention = 0;\r
 343 \r
 344                 enter_Status(CHECK_CONDITION);\r
 345         }\r
 346         else if (scsiDev.lun)\r
 347         {\r
 348                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 349                 scsiDev.target->sense.asc = LOGICAL_UNIT_NOT_SUPPORTED;\r
 350                 enter_Status(CHECK_CONDITION);\r
 351         }\r
 352         else if (command == 0x17 || command == 0x16)\r
 353         {\r
 354                 doReserveRelease();\r
 355         }\r
 356         else if ((scsiDev.target->reservedId >= 0) &&\r
 357                 (scsiDev.target->reservedId != scsiDev.initiatorId))\r
 358         {\r
 359                 enter_Status(CONFLICT);\r
 360         }\r
 361         // Handle odd device types first that may override basic read and\r
 362         // write commands. Will fall-through to generic disk handling.\r
 363         else if (((cfg->deviceType == S2S_CFG_OPTICAL) && scsiCDRomCommand()) ||\r
 364                 ((cfg->deviceType == S2S_CFG_SEQUENTIAL) && scsiTapeCommand()) ||\r
 365                 ((cfg->deviceType == S2S_CFG_MO) && scsiMOCommand()))\r
 366         {\r
 367                 // Already handled.\r
 368         }\r
 369         else if (scsiDiskCommand())\r
 370         {\r
 371                 // Already handled.\r
 372                 // check for the performance-critical read/write\r
 373                 // commands ASAP.\r
 374         }\r
 375         else if (command == 0x1C)\r
 376         {\r
 377                 scsiReceiveDiagnostic();\r
 378         }\r
 379         else if (command == 0x1D)\r
 380         {\r
 381                 scsiSendDiagnostic();\r
 382         }\r
 383         else if (command == 0x3B)\r
 384         {\r
 385                 scsiWriteBuffer();\r
 386         }\r
 387         else if (command == 0x3C)\r
 388         {\r
 389                 scsiReadBuffer();\r
 390         }\r
 391         else if (!scsiModeCommand())\r
 392         {\r
 393                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 394                 scsiDev.target->sense.asc = INVALID_COMMAND_OPERATION_CODE;\r
 395                 enter_Status(CHECK_CONDITION);\r
 396         }\r
 397 \r
 398         // Successful\r
 399         if (scsiDev.phase == COMMAND) // No status set, and not in DATA_IN\r
 400         {\r
 401                 enter_Status(GOOD);\r
 402         }\r
 403 \r
 404 }\r
 405 \r
 406 static void doReserveRelease()\r
 407 {\r
 408         int extentReservation = scsiDev.cdb[1] & 1;\r
 409         int thirdPty = scsiDev.cdb[1] & 0x10;\r
 410         int thirdPtyId = (scsiDev.cdb[1] >> 1) & 0x7;\r
 411         uint8_t command = scsiDev.cdb[0];\r
 412 \r
 413         int canRelease =\r
 414                 (!thirdPty && (scsiDev.initiatorId == scsiDev.target->reservedId)) ||\r
 415                         (thirdPty &&\r
 416                                 (scsiDev.target->reserverId == scsiDev.initiatorId) &&\r
 417                                 (scsiDev.target->reservedId == thirdPtyId)\r
 418                         );\r
 419 \r
 420         if (extentReservation)\r
 421         {\r
 422                 // Not supported.\r
 423                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
 424                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
 425                 enter_Status(CHECK_CONDITION);\r
 426         }\r
 427         else if (command == 0x17) // release\r
 428         {\r
 429                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 430                 {\r
 431                         scsiDev.target->reservedId = -1;\r
 432                         scsiDev.target->reserverId = -1;\r
 433                 }\r
 434                 else\r
 435                 {\r
 436                         enter_Status(CONFLICT);\r
 437                 }\r
 438         }\r
 439         else // assume reserve.\r
 440         {\r
 441                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
 442                 {\r
 443                         scsiDev.target->reserverId = scsiDev.initiatorId;\r
 444                         if (thirdPty)\r
 445                         {\r
 446                                 scsiDev.target->reservedId = thirdPtyId;\r
 447                         }\r
 448                         else\r
 449                         {\r
 450                                 scsiDev.target->reservedId = scsiDev.initiatorId;\r
 451                         }\r
 452                 }\r
 453                 else\r
 454                 {\r
 455                         // Already reserved by someone else!\r
 456                         enter_Status(CONFLICT);\r
 457                 }\r
 458         }\r
 459 }\r
 460 \r
 461 static void scsiReset()\r
 462 {\r
 463         scsiDev.rstCount++;\r
 464         s2s_ledOff();\r
 465 \r
 466         scsiPhyReset();\r
 467 \r
 468         scsiDev.phase = BUS_FREE;\r
 469         scsiDev.atnFlag = 0;\r
 470         scsiDev.resetFlag = 0;\r
 471         scsiDev.selFlag = 0;\r
 472         scsiDev.lun = -1;\r
 473         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 474 \r
 475         if (scsiDev.target)\r
 476         {\r
 477                 if (scsiDev.target->unitAttention != POWER_ON_RESET)\r
 478                 {\r
 479                         scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 480                 }\r
 481                 scsiDev.target->reservedId = -1;\r
 482                 scsiDev.target->reserverId = -1;\r
 483                 scsiDev.target->sense.code = NO_SENSE;\r
 484                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 485         }\r
 486         scsiDev.target = NULL;\r
 487 \r
 488         for (int i = 0; i < S2S_MAX_TARGETS; ++i)\r
 489         {\r
 490                 scsiDev.target[i].syncOffset = 0;\r
 491                 scsiDev.target[i].syncPeriod = 0;\r
 492         }\r
 493         scsiDev.minSyncPeriod = 0;\r
 494 \r
 495         scsiDiskReset();\r
 496 \r
 497         scsiDev.postDataOutHook = NULL;\r
 498 \r
 499         // Sleep to allow the bus to settle down a bit.\r
 500         // We must be ready again within the "Reset to selection time" of\r
 501         // 250ms.\r
 502         // There is no guarantee that the RST line will be negated by then.\r
 503         // NOTE: We could be connected and powered by USB for configuration,\r
 504         // in which case TERMPWR cannot be supplied, and reset will ALWAYS\r
 505         // be true. Therefore, the sleep here must be slow to avoid slowing\r
 506         // USB comms\r
 507         s2s_delay_ms(1); // 1ms.\r
 508 }\r
 509 \r
 510 static void enter_SelectionPhase()\r
 511 {\r
 512         // Ignore stale versions of this flag, but ensure we know the\r
 513         // current value if the flag is still set.\r
 514         scsiDev.atnFlag = 0;\r
 515         scsiDev.dataPtr = 0;\r
 516         scsiDev.savedDataPtr = 0;\r
 517         scsiDev.dataLen = 0;\r
 518         scsiDev.status = GOOD;\r
 519         scsiDev.phase = SELECTION;\r
 520         scsiDev.lun = -1;\r
 521         scsiDev.discPriv = 0;\r
 522 \r
 523         scsiDev.initiatorId = -1;\r
 524         scsiDev.target = NULL;\r
 525 \r
 526         transfer.blocks = 0;\r
 527         transfer.currentBlock = 0;\r
 528 \r
 529         scsiDev.postDataOutHook = NULL;\r
 530 \r
 531         scsiDev.needSyncNegotiationAck = 0;\r
 532 }\r
 533 \r
 534 static void process_SelectionPhase()\r
 535 {\r
 536         // Selection delays.\r
 537         // Many SCSI1 samplers that use a 5380 chip need a delay of at least 1ms.\r
 538         // The Mac Plus boot-time (ie. rom code) selection abort time\r
 539         // is < 1ms and must have no delay (standard suggests 250ms abort time)\r
 540         // Most newer SCSI2 hosts don't care either way.\r
 541         if (scsiDev.boardCfg.selectionDelay == 255) // auto\r
 542         {\r
 543                 if (scsiDev.compatMode < COMPAT_SCSI2)\r
 544                 {\r
 545                         s2s_delay_ms(1);\r
 546                 }\r
 547         }\r
 548         else if (scsiDev.boardCfg.selectionDelay != 0)\r
 549         {\r
 550                 s2s_delay_ms(scsiDev.boardCfg.selectionDelay);\r
 551         }\r
 552 \r
 553         uint8_t selStatus = *SCSI_STS_SELECTED;\r
 554         if ((selStatus == 0) && (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_SEL_LATCH))\r
 555         {\r
 556                 selStatus = scsiDev.selFlag;\r
 557         }\r
 558 \r
 559         int tgtIndex;\r
 560         TargetState* target = NULL;\r
 561         for (tgtIndex = 0; tgtIndex < S2S_MAX_TARGETS; ++tgtIndex)\r
 562         {\r
 563                 if (scsiDev.targets[tgtIndex].targetId == (selStatus & 7))\r
 564                 {\r
 565                         target = &scsiDev.targets[tgtIndex];\r
 566                         break;\r
 567                 }\r
 568         }\r
 569         if ((target != NULL) && (selStatus & 0x40))\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_CTRL_BSY = 1;\r
 578                 s2s_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 = selStatus & 0x80;\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 & S2S_CFG_ENABLE_SCSI2))\r
 598                 {\r
 599                         scsiDev.compatMode = COMPAT_SCSI1;\r
 600                 }\r
 601                 else\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                 scsiDev.initiatorId = (selStatus >> 3) & 0x7;\r
 613 \r
 614                 while (likely(!scsiDev.resetFlag) && scsiStatusSEL())\r
 615                 {\r
 616                         // Wait until the end of the selection phase.\r
 617                 }\r
 618 \r
 619                 scsiDev.phase = COMMAND;\r
 620         }\r
 621         else if (!selStatus)\r
 622         {\r
 623                 scsiDev.phase = BUS_BUSY;\r
 624         }\r
 625         scsiDev.selFlag = 0;\r
 626 }\r
 627 \r
 628 static void process_MessageOut()\r
 629 {\r
 630         scsiEnterPhase(MESSAGE_OUT);\r
 631 \r
 632         scsiDev.atnFlag = 0;\r
 633         scsiDev.msgOut = scsiReadByte();\r
 634         scsiDev.msgCount++;\r
 635 \r
 636         if (scsiParityError() &&\r
 637                 (scsiDev.boardCfg.flags & S2S_CFG_ENABLE_PARITY))\r
 638         {\r
 639                 // Skip the remaining message bytes, and then start the MESSAGE_OUT\r
 640                 // phase again from the start. The initiator will re-send the\r
 641                 // same set of messages.\r
 642                 while (scsiStatusATN() && !scsiDev.resetFlag)\r
 643                 {\r
 644                         scsiReadByte();\r
 645                 }\r
 646 \r
 647                 // Go-back and try the message again.\r
 648                 scsiDev.atnFlag = 1;\r
 649         }\r
 650         else if (scsiDev.msgOut == 0x00)\r
 651         {\r
 652                 // COMMAND COMPLETE. but why would the target be receiving this ? nfi.\r
 653                 enter_BusFree();\r
 654         }\r
 655         else if (scsiDev.msgOut == 0x06)\r
 656         {\r
 657                 // ABORT\r
 658                 scsiDiskReset();\r
 659                 enter_BusFree();\r
 660         }\r
 661         else if (scsiDev.msgOut == 0x0C)\r
 662         {\r
 663                 // BUS DEVICE RESET\r
 664 \r
 665                 scsiDiskReset();\r
 666 \r
 667                 scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
 668 \r
 669                 // ANY initiator can reset the reservation state via this message.\r
 670                 scsiDev.target->reservedId = -1;\r
 671                 scsiDev.target->reserverId = -1;\r
 672 \r
 673                 // Cancel any sync negotiation\r
 674                 scsiDev.target->syncOffset = 0;\r
 675                 scsiDev.target->syncPeriod = 0;\r
 676 \r
 677                 enter_BusFree();\r
 678         }\r
 679         else if (scsiDev.msgOut == 0x05)\r
 680         {\r
 681                 // Initiate Detected Error\r
 682                 // Ignore for now\r
 683         }\r
 684         else if (scsiDev.msgOut == 0x0F)\r
 685         {\r
 686                 // INITIATE RECOVERY\r
 687                 // Ignore for now\r
 688         }\r
 689         else if (scsiDev.msgOut == 0x10)\r
 690         {\r
 691                 // RELEASE RECOVERY\r
 692                 // Ignore for now\r
 693                 enter_BusFree();\r
 694         }\r
 695         else if (scsiDev.msgOut == MSG_REJECT)\r
 696         {\r
 697                 // Message Reject\r
 698                 // Oh well.\r
 699 \r
 700                 if (scsiDev.needSyncNegotiationAck)\r
 701                 {\r
 702                         scsiDev.target->syncOffset = 0;\r
 703                         scsiDev.target->syncPeriod = 0;\r
 704                         scsiDev.needSyncNegotiationAck = 0;\r
 705                 }\r
 706         }\r
 707         else if (scsiDev.msgOut == 0x08)\r
 708         {\r
 709                 // NOP\r
 710         }\r
 711         else if (scsiDev.msgOut == 0x09)\r
 712         {\r
 713                 // Message Parity Error\r
 714                 // Go back and re-send the last message.\r
 715                 scsiDev.phase = MESSAGE_IN;\r
 716         }\r
 717         else if (scsiDev.msgOut & 0x80) // 0x80 -> 0xFF\r
 718         {\r
 719                 // IDENTIFY\r
 720                 if ((scsiDev.msgOut & 0x18) || // Reserved bits set.\r
 721                         (scsiDev.msgOut & 0x20))  // We don't have any target routines!\r
 722                 {\r
 723                         messageReject();\r
 724                 }\r
 725 \r
 726                 scsiDev.lun = scsiDev.msgOut & 0x7;\r
 727                 scsiDev.discPriv = \r
 728                         ((scsiDev.msgOut & 0x40) && (scsiDev.initiatorId >= 0))\r
 729                                 ? 1 : 0;\r
 730         }\r
 731         else if (scsiDev.msgOut >= 0x20 && scsiDev.msgOut <= 0x2F)\r
 732         {\r
 733                 // Two byte message. We don't support these. read and discard.\r
 734                 scsiReadByte();\r
 735 \r
 736                 if (scsiDev.msgOut == 0x23) {\r
 737                         // Ignore Wide Residue. We're only 8 bit anyway.\r
 738                 } else {\r
 739                         messageReject();\r
 740                 }\r
 741         }\r
 742         else if (scsiDev.msgOut == 0x01)\r
 743         {\r
 744                 int i;\r
 745 \r
 746                 // Extended message.\r
 747                 int msgLen = scsiReadByte();\r
 748                 if (msgLen == 0) msgLen = 256;\r
 749                 uint8_t extmsg[256];\r
 750                 for (i = 0; i < msgLen && !scsiDev.resetFlag; ++i)\r
 751                 {\r
 752                         // Discard bytes.\r
 753                         extmsg[i] = scsiReadByte();\r
 754                 }\r
 755 \r
 756                 if (extmsg[0] == 3 && msgLen == 2) // Wide Data Request\r
 757                 {\r
 758                         // Negotiate down to 8bit\r
 759                         scsiEnterPhase(MESSAGE_IN);\r
 760                         static const uint8_t WDTR[] = {0x01, 0x02, 0x03, 0x00};\r
 761                         scsiWrite(WDTR, sizeof(WDTR));\r
 762                 }\r
 763                 else if (extmsg[0] == 1 && msgLen == 3) // Synchronous data request\r
 764                 {\r
 765                         int transferPeriod = extmsg[1];\r
 766                         int offset = extmsg[2];\r
 767 \r
 768                         if ((transferPeriod < scsiDev.minSyncPeriod) ||\r
 769                                 (scsiDev.minSyncPeriod == 0))\r
 770                         {\r
 771                                 scsiDev.minSyncPeriod = transferPeriod;\r
 772                         }\r
 773 \r
 774                         if ((transferPeriod > 80) || // 320ns, 3.125MB/s\r
 775                                 // Amiga A590 (WD33C93 chip) only does 3.5MB/s sync\r
 776                                 // After 80 we start to run out of bits in the fpga timing\r
 777                                 // register.\r
 778                                 (transferPeriod == 0))\r
 779                         {\r
 780                                 scsiDev.target->syncOffset = 0;\r
 781                                 scsiDev.target->syncPeriod = 0;\r
 782                         } else {\r
 783                                 scsiDev.target->syncOffset = offset < 63 ? offset : 63;\r
 784                                 // FAST20 / 50ns / 20MHz is disabled for now due to\r
 785                                 // data corruption while reading data. We can count the\r
 786                                 // ACK's correctly, but can't save the data to a register\r
 787                                 // before it changes.\r
 788                                 // TODO work out the fastest sync period that will work\r
 789                                 /*\r
 790                                 if (transferPeriod <= 12)\r
 791                                 {\r
 792                                         scsiDev.target->syncPeriod = 12; // 50ns, 20MB/s\r
 793                                 }\r
 794                                 else */if (transferPeriod <= 25)\r
 795                                 {\r
 796                                         scsiDev.target->syncPeriod = 25; // 100ns, 10MB/s\r
 797                                 } else {\r
 798                                         scsiDev.target->syncPeriod = transferPeriod;\r
 799                                 }\r
 800                         }\r
 801 \r
 802                         scsiEnterPhase(MESSAGE_IN);\r
 803                         uint8_t SDTR[] = {0x01, 0x03, 0x01, scsiDev.target->syncPeriod, scsiDev.target->syncOffset};\r
 804                         scsiWrite(SDTR, sizeof(SDTR));\r
 805                         scsiDev.needSyncNegotiationAck = 1; // Check if this message is rejected.\r
 806                 }\r
 807                 else\r
 808                 {\r
 809                         // Not supported\r
 810                         messageReject();\r
 811                 }\r
 812         }\r
 813         else\r
 814         {\r
 815                 messageReject();\r
 816         }\r
 817 \r
 818         // Re-check the ATN flag in case it stays asserted.\r
 819         scsiDev.atnFlag |= scsiStatusATN();\r
 820 \r
 821         if (!scsiDev.atnFlag)\r
 822         {\r
 823                 // Message wasn't rejected!\r
 824                 scsiDev.needSyncNegotiationAck = 0;\r
 825         }\r
 826 }\r
 827 \r
 828 void scsiPoll(void)\r
 829 {\r
 830         if (unlikely(scsiDev.resetFlag))\r
 831         {\r
 832                 scsiReset();\r
 833                 if ((scsiDev.resetFlag = scsiStatusRST()))\r
 834                 {\r
 835                         // Still in reset phase. Do not try and process any commands.\r
 836                         return;\r
 837                 }\r
 838         }\r
 839 \r
 840         switch (scsiDev.phase)\r
 841         {\r
 842         case BUS_FREE:\r
 843                 if (scsiStatusBSY())\r
 844                 {\r
 845                         scsiDev.phase = BUS_BUSY;\r
 846                 }\r
 847                 // The Arbitration phase is optional for SCSI1/SASI hosts if there is only\r
 848                 // one initiator in the chain. Support this by moving\r
 849                 // straight to selection if SEL is asserted.\r
 850                 // ie. the initiator won't assert BSY and it's own ID before moving to selection.\r
 851                 else if (scsiDev.selFlag || *SCSI_STS_SELECTED)\r
 852                 {\r
 853                         enter_SelectionPhase();\r
 854                 }\r
 855         break;\r
 856 \r
 857         case BUS_BUSY:\r
 858                 // Someone is using the bus. Perhaps they are trying to\r
 859                 // select us.\r
 860                 if (scsiDev.selFlag || *SCSI_STS_SELECTED)\r
 861                 {\r
 862                         enter_SelectionPhase();\r
 863                 }\r
 864                 else if (!scsiStatusBSY())\r
 865                 {\r
 866                         scsiDev.phase = BUS_FREE;\r
 867                 }\r
 868         break;\r
 869 \r
 870         case ARBITRATION:\r
 871                 // TODO Support reselection.\r
 872                 break;\r
 873 \r
 874         case SELECTION:\r
 875                 process_SelectionPhase();\r
 876         break;\r
 877 \r
 878         case RESELECTION:\r
 879                 // Not currently supported!\r
 880         break;\r
 881 \r
 882         case COMMAND:\r
 883                 // Do not check ATN here. SCSI 1 & 2 initiators must set ATN\r
 884                 // and SEL together upon entering the selection phase if they\r
 885                 // want to send a message (IDENTIFY) immediately.\r
 886                 if (scsiDev.atnFlag)\r
 887                 {\r
 888                         process_MessageOut();\r
 889                 }\r
 890                 else\r
 891                 {\r
 892                         process_Command();\r
 893                 }\r
 894         break;\r
 895 \r
 896         case DATA_IN:\r
 897                 scsiDev.atnFlag |= scsiStatusATN();\r
 898                 if (scsiDev.atnFlag)\r
 899                 {\r
 900                         process_MessageOut();\r
 901                 }\r
 902                 else\r
 903                 {\r
 904                         process_DataIn();\r
 905                 }\r
 906         break;\r
 907 \r
 908         case DATA_OUT:\r
 909                 scsiDev.atnFlag |= scsiStatusATN();\r
 910                 if (scsiDev.atnFlag)\r
 911                 {\r
 912                         process_MessageOut();\r
 913                 }\r
 914                 else\r
 915                 {\r
 916                         process_DataOut();\r
 917                 }\r
 918         break;\r
 919 \r
 920         case STATUS:\r
 921                 scsiDev.atnFlag |= scsiStatusATN();\r
 922                 if (scsiDev.atnFlag)\r
 923                 {\r
 924                         process_MessageOut();\r
 925                 }\r
 926                 else\r
 927                 {\r
 928                         process_Status();\r
 929                 }\r
 930         break;\r
 931 \r
 932         case MESSAGE_IN:\r
 933                 scsiDev.atnFlag |= scsiStatusATN();\r
 934                 if (scsiDev.atnFlag)\r
 935                 {\r
 936                         process_MessageOut();\r
 937                 }\r
 938                 else\r
 939                 {\r
 940                         process_MessageIn();\r
 941                 }\r
 942 \r
 943         break;\r
 944 \r
 945         case MESSAGE_OUT:\r
 946                 process_MessageOut();\r
 947         break;\r
 948         }\r
 949 }\r
 950 \r
 951 void scsiInit()\r
 952 {\r
 953         static int firstInit = 1;\r
 954 \r
 955         scsiDev.atnFlag = 0;\r
 956         scsiDev.resetFlag = 1;\r
 957         scsiDev.selFlag = 0;\r
 958         scsiDev.phase = BUS_FREE;\r
 959         scsiDev.target = NULL;\r
 960         scsiDev.compatMode = COMPAT_UNKNOWN;\r
 961 \r
 962         int i;\r
 963         for (i = 0; i < S2S_MAX_TARGETS; ++i)\r
 964         {\r
 965                 const S2S_TargetCfg* cfg = s2s_getConfigByIndex(i);\r
 966                 if (cfg && (cfg->scsiId & S2S_CFG_TARGET_ENABLED))\r
 967                 {\r
 968                         scsiDev.targets[i].targetId = cfg->scsiId & S2S_CFG_TARGET_ID_BITS;\r
 969                         scsiDev.targets[i].cfg = cfg;\r
 970 \r
 971                         scsiDev.targets[i].liveCfg.bytesPerSector = cfg->bytesPerSector;\r
 972                 }\r
 973                 else\r
 974                 {\r
 975                         scsiDev.targets[i].targetId = 0xff;\r
 976                         scsiDev.targets[i].cfg = NULL;\r
 977                 }\r
 978                 scsiDev.targets[i].reservedId = -1;\r
 979                 scsiDev.targets[i].reserverId = -1;\r
 980                 if (firstInit)\r
 981                 {\r
 982                         scsiDev.targets[i].unitAttention = POWER_ON_RESET;\r
 983                 }\r
 984                 else\r
 985                 {\r
 986                         scsiDev.targets[i].unitAttention = PARAMETERS_CHANGED;\r
 987                 }\r
 988                 scsiDev.targets[i].sense.code = NO_SENSE;\r
 989                 scsiDev.targets[i].sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
 990 \r
 991                 scsiDev.targets[i].syncOffset = 0;\r
 992                 scsiDev.targets[i].syncPeriod = 0;\r
 993         }\r
 994         firstInit = 0;\r
 995 }\r
 996 \r
 997 /* TODO REENABLE\r
 998 void scsiDisconnect()\r
 999 {\r
1000         scsiEnterPhase(MESSAGE_IN);\r
1001         scsiWriteByte(0x02); // save data pointer\r
1002         scsiWriteByte(0x04); // disconnect msg.\r
1003 \r
1004         // For now, the caller is responsible for tracking the disconnected\r
1005         // state, and calling scsiReconnect.\r
1006         // Ideally the client would exit their loop and we'd implement this\r
1007         // as part of scsiPoll\r
1008         int phase = scsiDev.phase;\r
1009         enter_BusFree();\r
1010         scsiDev.phase = phase;\r
1011 }\r
1012 */\r
1013 \r
1014 /* TODO REENABLE\r
1015 int scsiReconnect()\r
1016 {\r
1017         int reconnected = 0;\r
1018 \r
1019         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
1020         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1021         if (!sel && !bsy)\r
1022         {\r
1023                 s2s_delay_us(1);\r
1024                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
1025                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1026         }\r
1027 \r
1028         if (!sel && !bsy)\r
1029         {\r
1030                 // Arbitrate.\r
1031                 s2s_ledOn();\r
1032                 uint8_t scsiIdMask = 1 << scsiDev.target->targetId;\r
1033                 SCSI_Out_Bits_Write(scsiIdMask);\r
1034                 SCSI_Out_Ctl_Write(1); // Write bits manually.\r
1035                 SCSI_SetPin(SCSI_Out_BSY);\r
1036 \r
1037                 s2s_delay_us(3); // arbitrate delay. 2.4us.\r
1038 \r
1039                 uint8_t dbx = scsiReadDBxPins();\r
1040                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
1041                 if (sel || ((dbx ^ scsiIdMask) > scsiIdMask))\r
1042                 {\r
1043                         // Lost arbitration.\r
1044                         SCSI_Out_Ctl_Write(0);\r
1045                         SCSI_ClearPin(SCSI_Out_BSY);\r
1046                         s2s_ledOff();\r
1047                 }\r
1048                 else\r
1049                 {\r
1050                         // Won arbitration\r
1051                         SCSI_SetPin(SCSI_Out_SEL);\r
1052                         s2s_delay_us(1); // Bus clear + Bus settle.\r
1053 \r
1054                         // Reselection phase\r
1055                         SCSI_CTL_PHASE_Write(__scsiphase_io);\r
1056                         SCSI_Out_Bits_Write(scsiIdMask | (1 << scsiDev.initiatorId));\r
1057                         scsiDeskewDelay(); // 2 deskew delays\r
1058                         scsiDeskewDelay(); // 2 deskew delays\r
1059                         SCSI_ClearPin(SCSI_Out_BSY);\r
1060                         s2s_delay_us(1);  // Bus Settle Delay\r
1061 \r
1062                         uint32_t waitStart_ms = getTime_ms();\r
1063                         bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1064                         // Wait for initiator.\r
1065                         while (\r
1066                                 !bsy &&\r
1067                                 !scsiDev.resetFlag &&\r
1068                                 (elapsedTime_ms(waitStart_ms) < 250))\r
1069                         {\r
1070                                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
1071                         }\r
1072 \r
1073                         if (bsy)\r
1074                         {\r
1075                                 SCSI_SetPin(SCSI_Out_BSY);\r
1076                                 scsiDeskewDelay(); // 2 deskew delays\r
1077                                 scsiDeskewDelay(); // 2 deskew delays\r
1078                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1079 \r
1080                                 // Prepare for the initial IDENTIFY message.\r
1081                                 SCSI_Out_Ctl_Write(0);\r
1082                                 scsiEnterPhase(MESSAGE_IN);\r
1083 \r
1084                                 // Send identify command\r
1085                                 scsiWriteByte(0x80);\r
1086 \r
1087                                 scsiEnterPhase(scsiDev.phase);\r
1088                                 reconnected = 1;\r
1089                         }\r
1090                         else\r
1091                         {\r
1092                                 // reselect timeout.\r
1093                                 SCSI_Out_Ctl_Write(0);\r
1094                                 SCSI_ClearPin(SCSI_Out_SEL);\r
1095                                 SCSI_CTL_PHASE_Write(0);\r
1096                                 s2s_ledOff();\r
1097                         }\r
1098                 }\r
1099         }\r
1100         return reconnected;\r
1101 }\r
1102 */\r
1103 \r