Implement WRITE BUFFER and WRITE WITH VERIFY commands
[SCSI2SD-V6.git] / software / SCSI2SD / src / scsi.c
1 //      Copyright (C) 2014 Michael McMaster <michael@codesrc.com>\r
2 //\r
3 //      This file is part of SCSI2SD.\r
4 //\r
5 //      SCSI2SD is free software: you can redistribute it and/or modify\r
6 //      it under the terms of the GNU General Public License as published by\r
7 //      the Free Software Foundation, either version 3 of the License, or\r
8 //      (at your option) any later version.\r
9 //\r
10 //      SCSI2SD is distributed in the hope that it will be useful,\r
11 //      but WITHOUT ANY WARRANTY; without even the implied warranty of\r
12 //      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
13 //      GNU General Public License for more details.\r
14 //\r
15 //      You should have received a copy of the GNU General Public License\r
16 //      along with SCSI2SD.  If not, see <http://www.gnu.org/licenses/>.\r
17 #pragma GCC push_options\r
18 #pragma GCC optimize("-flto")\r
19 \r
20 #include "device.h"\r
21 #include "scsi.h"\r
22 #include "scsiPhy.h"\r
23 #include "config.h"\r
24 #include "bits.h"\r
25 #include "diagnostic.h"\r
26 #include "disk.h"\r
27 #include "inquiry.h"\r
28 #include "led.h"\r
29 #include "mode.h"\r
30 #include "disk.h"\r
31 #include "time.h"\r
32 #include "cdrom.h"\r
33 #include "debug.h"\r
34 \r
35 #include <string.h>\r
36 \r
37 // Global SCSI device state.\r
38 ScsiDevice scsiDev;\r
39 \r
40 static void enter_SelectionPhase(void);\r
41 static void process_SelectionPhase(void);\r
42 static void enter_BusFree(void);\r
43 static void enter_MessageIn(uint8 message);\r
44 static void enter_Status(uint8 status);\r
45 static void enter_DataIn(int len);\r
46 static void process_DataIn(void);\r
47 static void process_DataOut(void);\r
48 static void process_Command(void);\r
49 \r
50 static void doReserveRelease(void);\r
51 \r
52 static void enter_BusFree()\r
53 {\r
54         // This delay probably isn't needed for most SCSI hosts, but it won't\r
55         // hurt either. It's possible some of the samplers needed this delay.\r
56         if (scsiDev.compatMode)\r
57         {\r
58                 CyDelayUs(2);\r
59         }\r
60 \r
61         if (scsiDev.status != GOOD && isDebugEnabled())\r
62         {\r
63                 // We want to capture debug information for failure cases.\r
64                 CyDelay(64);\r
65         }\r
66 \r
67         SCSI_ClearPin(SCSI_Out_BSY);\r
68         // We now have a Bus Clear Delay of 800ns to release remaining signals.\r
69         SCSI_CTL_PHASE_Write(0);\r
70 \r
71         // Wait for the initiator to cease driving signals\r
72         // Bus settle delay + bus clear delay = 1200ns\r
73         CyDelayUs(2);\r
74 \r
75         ledOff();\r
76         scsiDev.phase = BUS_FREE;\r
77 }\r
78 \r
79 static void enter_MessageIn(uint8 message)\r
80 {\r
81         scsiDev.msgIn = message;\r
82         scsiDev.phase = MESSAGE_IN;\r
83 }\r
84 \r
85 void process_MessageIn()\r
86 {\r
87         scsiEnterPhase(MESSAGE_IN);\r
88         scsiWriteByte(scsiDev.msgIn);\r
89 \r
90         if (unlikely(scsiDev.atnFlag))\r
91         {\r
92                 // If there was a parity error, we go\r
93                 // back to MESSAGE_OUT first, get out parity error message, then come\r
94                 // back here.\r
95         }\r
96         else if ((scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE) ||\r
97                 (scsiDev.msgIn == MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG))\r
98         {\r
99                 // Go back to the command phase and start again.\r
100                 scsiDev.phase = COMMAND;\r
101                 scsiDev.parityError = 0;\r
102                 scsiDev.dataPtr = 0;\r
103                 scsiDev.savedDataPtr = 0;\r
104                 scsiDev.dataLen = 0;\r
105                 scsiDev.status = GOOD;\r
106                 transfer.blocks = 0;\r
107                 transfer.currentBlock = 0;\r
108         }\r
109         else /*if (scsiDev.msgIn == MSG_COMMAND_COMPLETE)*/\r
110         {\r
111                 enter_BusFree();\r
112         }\r
113 }\r
114 \r
115 static void messageReject()\r
116 {\r
117         scsiEnterPhase(MESSAGE_IN);\r
118         scsiWriteByte(MSG_REJECT);\r
119 }\r
120 \r
121 static void enter_Status(uint8 status)\r
122 {\r
123         scsiDev.status = status;\r
124         scsiDev.phase = STATUS;\r
125 \r
126         scsiDev.lastStatus = scsiDev.status;\r
127         scsiDev.lastSense = scsiDev.target->sense.code;\r
128         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
129 }\r
130 \r
131 void process_Status()\r
132 {\r
133         scsiEnterPhase(STATUS);\r
134 \r
135         uint8 message;\r
136 \r
137         uint8 control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
138         if ((scsiDev.status == GOOD) && (control & 0x01))\r
139         {\r
140                 // Linked command.\r
141                 scsiDev.status = INTERMEDIATE;\r
142                 if (control & 0x02)\r
143                 {\r
144                         message = MSG_LINKED_COMMAND_COMPLETE_WITH_FLAG;\r
145                 }\r
146                 else\r
147                 {\r
148                         message = MSG_LINKED_COMMAND_COMPLETE;\r
149                 }\r
150         }\r
151         else\r
152         {\r
153                 message = MSG_COMMAND_COMPLETE;\r
154         }\r
155         scsiWriteByte(scsiDev.status);\r
156 \r
157         scsiDev.lastStatus = scsiDev.status;\r
158         scsiDev.lastSense = scsiDev.target->sense.code;\r
159         scsiDev.lastSenseASC = scsiDev.target->sense.asc;\r
160 \r
161 \r
162         // Command Complete occurs AFTER a valid status has been\r
163         // sent. then we go bus-free.\r
164         enter_MessageIn(message);\r
165 }\r
166 \r
167 static void enter_DataIn(int len)\r
168 {\r
169         scsiDev.dataLen = len;\r
170         scsiDev.phase = DATA_IN;\r
171 }\r
172 \r
173 static void process_DataIn()\r
174 {\r
175         uint32 len;\r
176 \r
177         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
178         {\r
179                 scsiDev.dataLen = sizeof(scsiDev.data);\r
180         }\r
181 \r
182         len = scsiDev.dataLen - scsiDev.dataPtr;\r
183         if (len > 0)\r
184         {\r
185                 scsiEnterPhase(DATA_IN);\r
186                 scsiWrite(scsiDev.data + scsiDev.dataPtr, len);\r
187                 scsiDev.dataPtr += len;\r
188         }\r
189 \r
190         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
191                 (transfer.currentBlock == transfer.blocks))\r
192         {\r
193                 enter_Status(GOOD);\r
194         }\r
195 }\r
196 \r
197 static void process_DataOut()\r
198 {\r
199         uint32 len;\r
200 \r
201         if (scsiDev.dataLen > sizeof(scsiDev.data))\r
202         {\r
203                 scsiDev.dataLen = sizeof(scsiDev.data);\r
204         }\r
205 \r
206         scsiDev.parityError = 0;\r
207         len = scsiDev.dataLen - scsiDev.dataPtr;\r
208         if (len > 0)\r
209         {\r
210                 scsiEnterPhase(DATA_OUT);\r
211 \r
212                 scsiRead(scsiDev.data + scsiDev.dataPtr, len);\r
213                 scsiDev.dataPtr += len;\r
214 \r
215                 if (scsiDev.parityError &&\r
216                         (scsiDev.target->cfg->flags & CONFIG_ENABLE_PARITY) &&\r
217                         !scsiDev.compatMode)\r
218                 {\r
219                         scsiDev.target->sense.code = ABORTED_COMMAND;\r
220                         scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
221                         enter_Status(CHECK_CONDITION);\r
222                 }\r
223         }\r
224 \r
225         if ((scsiDev.dataPtr >= scsiDev.dataLen) &&\r
226                 (transfer.currentBlock == transfer.blocks))\r
227         {\r
228                 if (scsiDev.postDataOutHook != NULL)\r
229                 {\r
230                         scsiDev.postDataOutHook();\r
231                 }\r
232                 else\r
233                 {\r
234                         enter_Status(GOOD);\r
235                 }\r
236         }\r
237 }\r
238 \r
239 static const uint8 CmdGroupBytes[8] = {6, 10, 10, 6, 6, 12, 6, 6};\r
240 static void process_Command()\r
241 {\r
242         int group;\r
243         uint8 command;\r
244         uint8 control;\r
245 \r
246         scsiEnterPhase(COMMAND);\r
247         scsiDev.parityError = 0;\r
248 \r
249         memset(scsiDev.cdb, 0, sizeof(scsiDev.cdb));\r
250         scsiDev.cdb[0] = scsiReadByte();\r
251 \r
252         group = scsiDev.cdb[0] >> 5;\r
253         scsiDev.cdbLen = CmdGroupBytes[group];\r
254         scsiRead(scsiDev.cdb + 1, scsiDev.cdbLen - 1);\r
255 \r
256         command = scsiDev.cdb[0];\r
257 \r
258         // Prefer LUN's set by IDENTIFY messages for newer hosts.\r
259         if (scsiDev.lun < 0)\r
260         {\r
261                 scsiDev.lun = scsiDev.cdb[1] >> 5;\r
262         }\r
263 \r
264         control = scsiDev.cdb[scsiDev.cdbLen - 1];\r
265 \r
266         scsiDev.cmdCount++;\r
267 \r
268         if (unlikely(scsiDev.resetFlag))\r
269         {\r
270                 // Don't log bogus commands\r
271                 scsiDev.cmdCount--;\r
272                 memset(scsiDev.cdb, 0xff, sizeof(scsiDev.cdb));\r
273                 return;\r
274         }\r
275         else if (scsiDev.parityError &&\r
276                 (scsiDev.target->cfg->flags & CONFIG_ENABLE_PARITY) &&\r
277                 !scsiDev.compatMode)\r
278         {\r
279                 scsiDev.target->sense.code = ABORTED_COMMAND;\r
280                 scsiDev.target->sense.asc = SCSI_PARITY_ERROR;\r
281                 enter_Status(CHECK_CONDITION);\r
282         }\r
283         else if ((control & 0x02) && ((control & 0x01) == 0))\r
284         {\r
285                 // FLAG set without LINK flag.\r
286                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
287                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
288                 enter_Status(CHECK_CONDITION);\r
289         }\r
290         else if (command == 0x12)\r
291         {\r
292                 scsiInquiry();\r
293         }\r
294         else if (command == 0x03)\r
295         {\r
296                 // REQUEST SENSE\r
297                 uint32 allocLength = scsiDev.cdb[4];\r
298 \r
299                 // As specified by the SASI and SCSI1 standard.\r
300                 // Newer initiators won't be specifying 0 anyway.\r
301                 if (allocLength == 0) allocLength = 4;\r
302 \r
303                 memset(scsiDev.data, 0, 256); // Max possible alloc length\r
304                 scsiDev.data[0] = 0xF0;\r
305                 scsiDev.data[2] = scsiDev.target->sense.code & 0x0F;\r
306 \r
307                 scsiDev.data[3] = transfer.lba >> 24;\r
308                 scsiDev.data[4] = transfer.lba >> 16;\r
309                 scsiDev.data[5] = transfer.lba >> 8;\r
310                 scsiDev.data[6] = transfer.lba;\r
311 \r
312                 // Additional bytes if there are errors to report\r
313                 scsiDev.data[7] = 10; // additional length\r
314                 scsiDev.data[12] = scsiDev.target->sense.asc >> 8;\r
315                 scsiDev.data[13] = scsiDev.target->sense.asc;\r
316 \r
317                 // Silently truncate results. SCSI-2 spec 8.2.14.\r
318                 enter_DataIn(allocLength);\r
319 \r
320                 // This is a good time to clear out old sense information.\r
321                 scsiDev.target->sense.code = NO_SENSE;\r
322                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
323         }\r
324         // Some old SCSI drivers do NOT properly support\r
325         // unitAttention. eg. the Mac Plus would trigger a SCSI reset\r
326         // on receiving the unit attention response on boot, thus\r
327         // triggering another unit attention condition.\r
328         else if (scsiDev.target->unitAttention &&\r
329                 (scsiDev.target->cfg->flags & CONFIG_ENABLE_UNIT_ATTENTION))\r
330         {\r
331                 scsiDev.target->sense.code = UNIT_ATTENTION;\r
332                 scsiDev.target->sense.asc = scsiDev.target->unitAttention;\r
333 \r
334                 // If initiator doesn't do REQUEST SENSE for the next command, then\r
335                 // data is lost.\r
336                 scsiDev.target->unitAttention = 0;\r
337 \r
338                 enter_Status(CHECK_CONDITION);\r
339         }\r
340         else if (scsiDev.lun)\r
341         {\r
342                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
343                 scsiDev.target->sense.asc = LOGICAL_UNIT_NOT_SUPPORTED;\r
344                 enter_Status(CHECK_CONDITION);\r
345         }\r
346         else if (command == 0x17 || command == 0x16)\r
347         {\r
348                 doReserveRelease();\r
349         }\r
350         else if ((scsiDev.target->reservedId >= 0) &&\r
351                 (scsiDev.target->reservedId != scsiDev.initiatorId))\r
352         {\r
353                 enter_Status(CONFLICT);\r
354         }\r
355         else if (scsiDiskCommand())\r
356         {\r
357                 // Already handled.\r
358                 // check for the performance-critical read/write\r
359                 // commands ASAP.\r
360         }\r
361         else if (command == 0x1C)\r
362         {\r
363                 scsiReceiveDiagnostic();\r
364         }\r
365         else if (command == 0x1D)\r
366         {\r
367                 scsiSendDiagnostic();\r
368         }\r
369         else if (command == 0x3B)\r
370         {\r
371                 scsiWriteBuffer();\r
372         }\r
373         else if (command == 0x3C)\r
374         {\r
375                 scsiReadBuffer();\r
376         }\r
377         else if (\r
378                 !scsiCDRomCommand() &&\r
379                 !scsiModeCommand())\r
380         {\r
381                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
382                 scsiDev.target->sense.asc = INVALID_COMMAND_OPERATION_CODE;\r
383                 enter_Status(CHECK_CONDITION);\r
384         }\r
385 \r
386         // Successful\r
387         if (scsiDev.phase == COMMAND) // No status set, and not in DATA_IN\r
388         {\r
389                 enter_Status(GOOD);\r
390         }\r
391 \r
392 }\r
393 \r
394 static void doReserveRelease()\r
395 {\r
396         int extentReservation = scsiDev.cdb[1] & 1;\r
397         int thirdPty = scsiDev.cdb[1] & 0x10;\r
398         int thirdPtyId = (scsiDev.cdb[1] >> 1) & 0x7;\r
399         uint8 command = scsiDev.cdb[0];\r
400 \r
401         int canRelease =\r
402                 (!thirdPty && (scsiDev.initiatorId == scsiDev.target->reservedId)) ||\r
403                         (thirdPty &&\r
404                                 (scsiDev.target->reserverId == scsiDev.initiatorId) &&\r
405                                 (scsiDev.target->reservedId == thirdPtyId)\r
406                         );\r
407 \r
408         if (extentReservation)\r
409         {\r
410                 // Not supported.\r
411                 scsiDev.target->sense.code = ILLEGAL_REQUEST;\r
412                 scsiDev.target->sense.asc = INVALID_FIELD_IN_CDB;\r
413                 enter_Status(CHECK_CONDITION);\r
414         }\r
415         else if (command == 0x17) // release\r
416         {\r
417                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
418                 {\r
419                         scsiDev.target->reservedId = -1;\r
420                         scsiDev.target->reserverId = -1;\r
421                 }\r
422                 else\r
423                 {\r
424                         enter_Status(CONFLICT);\r
425                 }\r
426         }\r
427         else // assume reserve.\r
428         {\r
429                 if ((scsiDev.target->reservedId < 0) || canRelease)\r
430                 {\r
431                         scsiDev.target->reserverId = scsiDev.initiatorId;\r
432                         if (thirdPty)\r
433                         {\r
434                                 scsiDev.target->reservedId = thirdPtyId;\r
435                         }\r
436                         else\r
437                         {\r
438                                 scsiDev.target->reservedId = scsiDev.initiatorId;\r
439                         }\r
440                 }\r
441                 else\r
442                 {\r
443                         // Already reserved by someone else!\r
444                         enter_Status(CONFLICT);\r
445                 }\r
446         }\r
447 }\r
448 \r
449 static void scsiReset()\r
450 {\r
451         scsiDev.rstCount++;\r
452         ledOff();\r
453 \r
454         scsiPhyReset();\r
455         SCSI_Out_Ctl_Write(0);\r
456 \r
457         scsiDev.parityError = 0;\r
458         scsiDev.phase = BUS_FREE;\r
459         scsiDev.atnFlag = 0;\r
460         scsiDev.resetFlag = 0;\r
461         scsiDev.lun = -1;\r
462 \r
463         if (scsiDev.target)\r
464         {\r
465                 if (scsiDev.target->unitAttention != POWER_ON_RESET)\r
466                 {\r
467                         scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
468                 }\r
469                 scsiDev.target->reservedId = -1;\r
470                 scsiDev.target->reserverId = -1;\r
471                 scsiDev.target->sense.code = NO_SENSE;\r
472                 scsiDev.target->sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
473         }\r
474         scsiDev.target = NULL;\r
475         scsiDiskReset();\r
476 \r
477         scsiDev.postDataOutHook = NULL;\r
478 \r
479         // Sleep to allow the bus to settle down a bit.\r
480         // We must be ready again within the "Reset to selection time" of\r
481         // 250ms.\r
482         // There is no guarantee that the RST line will be negated by then.\r
483         // NOTE: We could be connected and powered by USB for configuration,\r
484         // in which case TERMPWR cannot be supplied, and reset will ALWAYS\r
485         // be true. Therefore, the sleep here must be slow to avoid slowing\r
486         // USB comms\r
487         CyDelay(1); // 1ms.\r
488 }\r
489 \r
490 static void enter_SelectionPhase()\r
491 {\r
492         // Ignore stale versions of this flag, but ensure we know the\r
493         // current value if the flag is still set.\r
494         scsiDev.atnFlag = 0;\r
495         scsiDev.parityError = 0;\r
496         scsiDev.dataPtr = 0;\r
497         scsiDev.savedDataPtr = 0;\r
498         scsiDev.dataLen = 0;\r
499         scsiDev.status = GOOD;\r
500         scsiDev.phase = SELECTION;\r
501         scsiDev.lun = -1;\r
502         scsiDev.discPriv = 0;\r
503         scsiDev.compatMode = 0;\r
504 \r
505         scsiDev.initiatorId = -1;\r
506         scsiDev.target = NULL;\r
507 \r
508         transfer.blocks = 0;\r
509         transfer.currentBlock = 0;\r
510 \r
511         scsiDev.postDataOutHook = NULL;\r
512 }\r
513 \r
514 static void process_SelectionPhase()\r
515 {\r
516         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
517         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
518 \r
519         // Only read these pins AFTER SEL and BSY - we don't want to catch them\r
520         // during a transition period.\r
521         uint8 mask = scsiReadDBxPins();\r
522         int maskBitCount = countBits(mask);\r
523         int goodParity = (Lookup_OddParity[mask] == SCSI_ReadPin(SCSI_In_DBP));\r
524         int atnFlag = SCSI_ReadFilt(SCSI_Filt_ATN);\r
525 \r
526         int tgtIndex;\r
527         TargetState* target = NULL;\r
528         for (tgtIndex = 0; tgtIndex < MAX_SCSI_TARGETS; ++tgtIndex)\r
529         {\r
530                 if (mask & (1 << scsiDev.targets[tgtIndex].targetId))\r
531                 {\r
532                         target = &scsiDev.targets[tgtIndex];\r
533                         break;\r
534                 }\r
535         }\r
536         if (!bsy && sel &&\r
537                 target &&\r
538                 (goodParity || !(target->cfg->flags & CONFIG_ENABLE_PARITY) || !atnFlag) &&\r
539                 likely(maskBitCount <= 2))\r
540         {\r
541                 scsiDev.target = target;\r
542 \r
543                 // Do we enter MESSAGE OUT immediately ? SCSI 1 and 2 standards says\r
544                 // move to MESSAGE OUT if ATN is true before we assert BSY.\r
545                 // The initiator should assert ATN with SEL.\r
546                 scsiDev.atnFlag = atnFlag;\r
547 \r
548                 // Unit attention breaks many older SCSI hosts. Disable it completely\r
549                 // for SCSI-1 (and older) hosts, regardless of our configured setting.\r
550                 // Enable the compatability mode also as many SASI and SCSI1\r
551                 // controllers don't generate parity bits.\r
552                 if (!scsiDev.atnFlag)\r
553                 {\r
554                         target->unitAttention = 0;\r
555                         scsiDev.compatMode = 1;\r
556                 }\r
557 \r
558                 // We've been selected!\r
559                 // Assert BSY - Selection success!\r
560                 // must happen within 200us (Selection abort time) of seeing our\r
561                 // ID + SEL.\r
562                 // (Note: the initiator will be waiting the "Selection time-out delay"\r
563                 // for our BSY response, which is actually a very generous 250ms)\r
564                 SCSI_SetPin(SCSI_Out_BSY);\r
565                 ledOn();\r
566 \r
567                 scsiDev.selCount++;\r
568 \r
569                 // Wait until the end of the selection phase.\r
570                 while (likely(!scsiDev.resetFlag))\r
571                 {\r
572                         if (!SCSI_ReadFilt(SCSI_Filt_SEL))\r
573                         {\r
574                                 break;\r
575                         }\r
576                 }\r
577 \r
578                 // Save our initiator now that we're no longer in a time-critical\r
579                 // section.\r
580                 // SCSI1/SASI initiators may not set their own ID.\r
581                 {\r
582                         int i;\r
583                         uint8_t initiatorMask = mask ^ (1 << target->targetId);\r
584                         scsiDev.initiatorId = -1;\r
585                         for (i = 0; i < 8; ++i)\r
586                         {\r
587                                 if (initiatorMask & (1 << i))\r
588                                 {\r
589                                         scsiDev.initiatorId = i;\r
590                                         break;\r
591                                 }\r
592                         }\r
593                 }\r
594 \r
595                 scsiDev.phase = COMMAND;\r
596         }\r
597         else if (!sel)\r
598         {\r
599                 scsiDev.phase = BUS_BUSY;\r
600         }\r
601 }\r
602 \r
603 static void process_MessageOut()\r
604 {\r
605         scsiEnterPhase(MESSAGE_OUT);\r
606 \r
607         scsiDev.atnFlag = 0;\r
608         scsiDev.parityError = 0;\r
609         scsiDev.msgOut = scsiReadByte();\r
610         scsiDev.msgCount++;\r
611 \r
612         if (scsiDev.parityError &&\r
613                 (scsiDev.target->cfg->flags & CONFIG_ENABLE_PARITY) &&\r
614                 !scsiDev.compatMode)\r
615         {\r
616                 // Skip the remaining message bytes, and then start the MESSAGE_OUT\r
617                 // phase again from the start. The initiator will re-send the\r
618                 // same set of messages.\r
619                 while (SCSI_ReadFilt(SCSI_Filt_ATN) && !scsiDev.resetFlag)\r
620                 {\r
621                         scsiReadByte();\r
622                 }\r
623 \r
624                 // Go-back and try the message again.\r
625                 scsiDev.atnFlag = 1;\r
626                 scsiDev.parityError = 0;\r
627         }\r
628         else if (scsiDev.msgOut == 0x00)\r
629         {\r
630                 // COMMAND COMPLETE. but why would the target be receiving this ? nfi.\r
631                 enter_BusFree();\r
632         }\r
633         else if (scsiDev.msgOut == 0x06)\r
634         {\r
635                 // ABORT\r
636                 scsiDiskReset();\r
637                 enter_BusFree();\r
638         }\r
639         else if (scsiDev.msgOut == 0x0C)\r
640         {\r
641                 // BUS DEVICE RESET\r
642 \r
643                 scsiDiskReset();\r
644 \r
645                 scsiDev.target->unitAttention = SCSI_BUS_RESET;\r
646 \r
647                 // ANY initiator can reset the reservation state via this message.\r
648                 scsiDev.target->reservedId = -1;\r
649                 scsiDev.target->reserverId = -1;\r
650                 enter_BusFree();\r
651         }\r
652         else if (scsiDev.msgOut == 0x05)\r
653         {\r
654                 // Initiate Detected Error\r
655                 // Ignore for now\r
656         }\r
657         else if (scsiDev.msgOut == 0x0F)\r
658         {\r
659                 // INITIATE RECOVERY\r
660                 // Ignore for now\r
661         }\r
662         else if (scsiDev.msgOut == 0x10)\r
663         {\r
664                 // RELEASE RECOVERY\r
665                 // Ignore for now\r
666                 enter_BusFree();\r
667         }\r
668         else if (scsiDev.msgOut == MSG_REJECT)\r
669         {\r
670                 // Message Reject\r
671                 // Oh well.\r
672                 scsiDev.resetFlag = 1;\r
673         }\r
674         else if (scsiDev.msgOut == 0x08)\r
675         {\r
676                 // NOP\r
677         }\r
678         else if (scsiDev.msgOut == 0x09)\r
679         {\r
680                 // Message Parity Error\r
681                 // Go back and re-send the last message.\r
682                 scsiDev.phase = MESSAGE_IN;\r
683         }\r
684         else if (scsiDev.msgOut & 0x80) // 0x80 -> 0xFF\r
685         {\r
686                 // IDENTIFY\r
687                 if ((scsiDev.msgOut & 0x18) || // Reserved bits set.\r
688                         (scsiDev.msgOut & 0x20))  // We don't have any target routines!\r
689                 {\r
690                         messageReject();\r
691                 }\r
692 \r
693                 scsiDev.lun = scsiDev.msgOut & 0x7;\r
694                 scsiDev.discPriv = \r
695                         ((scsiDev.msgOut & 0x40) && (scsiDev.initiatorId >= 0))\r
696                                 ? 1 : 0;\r
697         }\r
698         else if (scsiDev.msgOut >= 0x20 && scsiDev.msgOut <= 0x2F)\r
699         {\r
700                 // Two byte message. We don't support these. read and discard.\r
701                 scsiReadByte();\r
702         }\r
703         else if (scsiDev.msgOut == 0x01)\r
704         {\r
705                 int i;\r
706 \r
707                 // Extended message.\r
708                 int msgLen = scsiReadByte();\r
709                 if (msgLen == 0) msgLen = 256;\r
710                 uint8_t extmsg[256];\r
711                 for (i = 0; i < msgLen && !scsiDev.resetFlag; ++i)\r
712                 {\r
713                         // Discard bytes.\r
714                         extmsg[i] = scsiReadByte();\r
715                 }\r
716                 \r
717                 if (extmsg[0] == 3 && msgLen == 2) // Wide Data Request\r
718                 {\r
719                         // Negotiate down to 8bit\r
720                         scsiEnterPhase(MESSAGE_IN);\r
721                         static const uint8_t WDTR[] = {0x01, 0x02, 0x03, 0x00};\r
722                         scsiWrite(WDTR, sizeof(WDTR));\r
723                 }\r
724                 else if (extmsg[0] == 1 && msgLen == 5) // Synchronous data request\r
725                 {\r
726                         // Negotiate back to async\r
727                         scsiEnterPhase(MESSAGE_IN);\r
728                         static const uint8_t SDTR[] = {0x01, 0x03, 0x01, 0x00, 0x00};\r
729                         scsiWrite(SDTR, sizeof(SDTR));\r
730                 }\r
731                 else\r
732                 {\r
733                         // Not supported\r
734                         messageReject();\r
735                 }\r
736         }\r
737         else\r
738         {\r
739                 messageReject();\r
740         }\r
741 \r
742         // Re-check the ATN flag in case it stays asserted.\r
743         scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
744 }\r
745 \r
746 void scsiPoll(void)\r
747 {\r
748         if (unlikely(scsiDev.resetFlag))\r
749         {\r
750                 scsiReset();\r
751                 if ((scsiDev.resetFlag = SCSI_ReadFilt(SCSI_Filt_RST)))\r
752                 {\r
753                         // Still in reset phase. Do not try and process any commands.\r
754                         return;\r
755                 }\r
756         }\r
757 \r
758         switch (scsiDev.phase)\r
759         {\r
760         case BUS_FREE:\r
761                 if (SCSI_ReadFilt(SCSI_Filt_BSY))\r
762                 {\r
763                         scsiDev.phase = BUS_BUSY;\r
764                 }\r
765                 // The Arbitration phase is optional for SCSI1/SASI hosts if there is only\r
766                 // one initiator in the chain. Support this by moving\r
767                 // straight to selection if SEL is asserted.\r
768                 // ie. the initiator won't assert BSY and it's own ID before moving to selection.\r
769                 else if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
770                 {\r
771                         enter_SelectionPhase();\r
772                 }\r
773         break;\r
774 \r
775         case BUS_BUSY:\r
776                 // Someone is using the bus. Perhaps they are trying to\r
777                 // select us.\r
778                 if (SCSI_ReadFilt(SCSI_Filt_SEL))\r
779                 {\r
780                         enter_SelectionPhase();\r
781                 }\r
782                 else if (!SCSI_ReadFilt(SCSI_Filt_BSY))\r
783                 {\r
784                         scsiDev.phase = BUS_FREE;\r
785                 }\r
786         break;\r
787 \r
788         case ARBITRATION:\r
789                 // TODO Support reselection.\r
790                 break;\r
791 \r
792         case SELECTION:\r
793                 process_SelectionPhase();\r
794         break;\r
795 \r
796         case RESELECTION:\r
797                 // Not currently supported!\r
798         break;\r
799 \r
800         case COMMAND:\r
801                 // Do not check ATN here. SCSI 1 & 2 initiators must set ATN\r
802                 // and SEL together upon entering the selection phase if they\r
803                 // want to send a message (IDENTIFY) immediately.\r
804                 if (scsiDev.atnFlag)\r
805                 {\r
806                         process_MessageOut();\r
807                 }\r
808                 else\r
809                 {\r
810                         process_Command();\r
811                 }\r
812         break;\r
813 \r
814         case DATA_IN:\r
815                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
816                 if (scsiDev.atnFlag)\r
817                 {\r
818                         process_MessageOut();\r
819                 }\r
820                 else\r
821                 {\r
822                         process_DataIn();\r
823                 }\r
824         break;\r
825 \r
826         case DATA_OUT:\r
827                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
828                 if (scsiDev.atnFlag)\r
829                 {\r
830                         process_MessageOut();\r
831                 }\r
832                 else\r
833                 {\r
834                         process_DataOut();\r
835                 }\r
836         break;\r
837 \r
838         case STATUS:\r
839                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
840                 if (scsiDev.atnFlag)\r
841                 {\r
842                         process_MessageOut();\r
843                 }\r
844                 else\r
845                 {\r
846                         process_Status();\r
847                 }\r
848         break;\r
849 \r
850         case MESSAGE_IN:\r
851                 scsiDev.atnFlag |= SCSI_ReadFilt(SCSI_Filt_ATN);\r
852                 if (scsiDev.atnFlag)\r
853                 {\r
854                         process_MessageOut();\r
855                 }\r
856                 else\r
857                 {\r
858                         process_MessageIn();\r
859                 }\r
860 \r
861         break;\r
862 \r
863         case MESSAGE_OUT:\r
864                 process_MessageOut();\r
865         break;\r
866         }\r
867 }\r
868 \r
869 void scsiInit()\r
870 {\r
871         scsiDev.atnFlag = 0;\r
872         scsiDev.resetFlag = 1;\r
873         scsiDev.phase = BUS_FREE;\r
874         scsiDev.target = NULL;\r
875 \r
876         int i;\r
877         for (i = 0; i < MAX_SCSI_TARGETS; ++i)\r
878         {\r
879                 const TargetConfig* cfg = getConfigByIndex(i);\r
880                 if (cfg && (cfg->scsiId & CONFIG_TARGET_ENABLED))\r
881                 {\r
882                         scsiDev.targets[i].targetId = cfg->scsiId & CONFIG_TARGET_ID_BITS;\r
883                         scsiDev.targets[i].cfg = cfg;\r
884 \r
885                         scsiDev.targets[i].liveCfg.bytesPerSector = cfg->bytesPerSector;\r
886                 }\r
887                 else\r
888                 {\r
889                         scsiDev.targets[i].targetId = 0xff;\r
890                         scsiDev.targets[i].cfg = NULL;\r
891                 }\r
892                 scsiDev.targets[i].reservedId = -1;\r
893                 scsiDev.targets[i].reserverId = -1;\r
894                 scsiDev.targets[i].unitAttention = POWER_ON_RESET;\r
895                 scsiDev.targets[i].sense.code = NO_SENSE;\r
896                 scsiDev.targets[i].sense.asc = NO_ADDITIONAL_SENSE_INFORMATION;\r
897         }\r
898 }\r
899 \r
900 void scsiDisconnect()\r
901 {\r
902         scsiEnterPhase(MESSAGE_IN);\r
903         scsiWriteByte(0x02); // save data pointer\r
904         scsiWriteByte(0x04); // disconnect msg.\r
905 \r
906         // For now, the caller is responsible for tracking the disconnected\r
907         // state, and calling scsiReconnect.\r
908         // Ideally the client would exit their loop and we'd implement this\r
909         // as part of scsiPoll\r
910         int phase = scsiDev.phase;\r
911         enter_BusFree();\r
912         scsiDev.phase = phase;\r
913 }\r
914 \r
915 int scsiReconnect()\r
916 {\r
917         int reconnected = 0;\r
918 \r
919         int sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
920         int bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
921         if (!sel && !bsy)\r
922         {\r
923                 CyDelayUs(1);\r
924                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
925                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
926         }\r
927 \r
928         if (!sel && !bsy)\r
929         {\r
930                 // Arbitrate.\r
931                 ledOn();\r
932                 uint8_t scsiIdMask = 1 << scsiDev.target->targetId;\r
933                 SCSI_Out_Bits_Write(scsiIdMask);\r
934                 SCSI_Out_Ctl_Write(1); // Write bits manually.\r
935                 SCSI_SetPin(SCSI_Out_BSY);\r
936 \r
937                 CyDelayUs(3); // arbitrate delay. 2.4us.\r
938 \r
939                 uint8_t dbx = scsiReadDBxPins();\r
940                 sel = SCSI_ReadFilt(SCSI_Filt_SEL);\r
941                 if (sel || ((dbx ^ scsiIdMask) > scsiIdMask))\r
942                 {\r
943                         // Lost arbitration.\r
944                         SCSI_Out_Ctl_Write(0);\r
945                         SCSI_ClearPin(SCSI_Out_BSY);\r
946                         ledOff();\r
947                 }\r
948                 else\r
949                 {\r
950                         // Won arbitration\r
951                         SCSI_SetPin(SCSI_Out_SEL);\r
952                         CyDelayUs(1); // Bus clear + Bus settle.\r
953 \r
954                         // Reselection phase\r
955                         SCSI_CTL_PHASE_Write(__scsiphase_io);\r
956                         SCSI_Out_Bits_Write(scsiIdMask | (1 << scsiDev.initiatorId));\r
957                         scsiDeskewDelay(); // 2 deskew delays\r
958                         scsiDeskewDelay(); // 2 deskew delays\r
959                         SCSI_ClearPin(SCSI_Out_BSY);\r
960                         CyDelayUs(1);  // Bus Settle Delay\r
961 \r
962                         uint32_t waitStart_ms = getTime_ms();\r
963                         bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
964                         // Wait for initiator.\r
965                         while (\r
966                                 !bsy &&\r
967                                 !scsiDev.resetFlag &&\r
968                                 (elapsedTime_ms(waitStart_ms) < 250))\r
969                         {\r
970                                 bsy = SCSI_ReadFilt(SCSI_Filt_BSY);\r
971                         }\r
972 \r
973                         if (bsy)\r
974                         {\r
975                                 SCSI_SetPin(SCSI_Out_BSY);\r
976                                 scsiDeskewDelay(); // 2 deskew delays\r
977                                 scsiDeskewDelay(); // 2 deskew delays\r
978                                 SCSI_ClearPin(SCSI_Out_SEL);\r
979 \r
980                                 // Prepare for the initial IDENTIFY message.\r
981                                 SCSI_Out_Ctl_Write(0);\r
982                                 scsiEnterPhase(MESSAGE_IN);\r
983 \r
984                                 // Send identify command\r
985                                 scsiWriteByte(0x80);\r
986 \r
987                                 scsiEnterPhase(scsiDev.phase);\r
988                                 reconnected = 1;\r
989                         }\r
990                         else\r
991                         {\r
992                                 // reselect timeout.\r
993                                 SCSI_Out_Ctl_Write(0);\r
994                                 SCSI_ClearPin(SCSI_Out_SEL);\r
995                                 SCSI_CTL_PHASE_Write(0);\r
996                                 ledOff();\r
997                         }\r
998                 }\r
999         }\r
1000         return reconnected;\r
1001 }\r
1002 \r
1003 #pragma GCC pop_options\r