git.sur5r.net Git - openocd/blob - src/jtag/core.c

   1 /***************************************************************************
   2  *   Copyright (C) 2009 Zachary T Welch                                    *
   3  *   zw@superlucidity.net                                                  *
   4  *                                                                         *
   5  *   Copyright (C) 2007,2008,2009 Øyvind Harboe                            *
   6  *   oyvind.harboe@zylin.com                                               *
   7  *                                                                         *
   8  *   Copyright (C) 2009 SoftPLC Corporation                                *
   9  *       http://softplc.com                                                *
  10  *   dick@softplc.com                                                      *
  11  *                                                                         *
  12  *   Copyright (C) 2005 by Dominic Rath                                    *
  13  *   Dominic.Rath@gmx.de                                                   *
  14  *                                                                         *
  15  *   This program is free software; you can redistribute it and/or modify  *
  16  *   it under the terms of the GNU General Public License as published by  *
  17  *   the Free Software Foundation; either version 2 of the License, or     *
  18  *   (at your option) any later version.                                   *
  19  *                                                                         *
  20  *   This program is distributed in the hope that it will be useful,       *
  21  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  22  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  23  *   GNU General Public License for more details.                          *
  24  *                                                                         *
  25  *   You should have received a copy of the GNU General Public License     *
  26  *   along with this program; if not, write to the                         *
  27  *   Free Software Foundation, Inc.,                                       *
  28  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  29  ***************************************************************************/
  30 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #include "jtag.h"
  35 #include "minidriver.h"
  36 #include "interface.h"
  37
  38 #ifdef HAVE_STRINGS_H
  39 #include <strings.h>
  40 #endif
  41
  42
  43 /// The number of JTAG queue flushes (for profiling and debugging purposes).
  44 static int jtag_flush_queue_count;
  45
  46 static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, const scan_field_t *in_fields, tap_state_t state),
  47                 int in_num_fields, scan_field_t *in_fields, tap_state_t state);
  48
  49 /**
  50  * The jtag_error variable is set when an error occurs while executing
  51  * the queue.  Application code may set this using jtag_set_error(),
  52  * when an error occurs during processing that should be reported during
  53  * jtag_execute_queue().
  54  *
  55  * Tts value may be checked with jtag_get_error() and cleared with
  56  * jtag_error_clear().  This value is returned (and cleared) by
  57  * jtag_execute_queue().
  58  */
  59 static int jtag_error = ERROR_OK;
  60
  61 static const char *jtag_event_strings[] =
  62 {
  63         [JTAG_TRST_ASSERTED] = "TAP reset",
  64         [JTAG_TAP_EVENT_SETUP] = "TAP setup",
  65         [JTAG_TAP_EVENT_ENABLE] = "TAP enabled",
  66         [JTAG_TAP_EVENT_DISABLE] = "TAP disabled",
  67 };
  68
  69 /*
  70  * JTAG adapters must initialize with TRST and SRST de-asserted
  71  * (they're negative logic, so that means *high*).  But some
  72  * hardware doesn't necessarily work that way ... so set things
  73  * up so that jtag_init() always forces that state.
  74  */
  75 static int jtag_trst = -1;
  76 static int jtag_srst = -1;
  77
  78 /**
  79  * List all TAPs that have been created.
  80  */
  81 static jtag_tap_t *__jtag_all_taps = NULL;
  82 /**
  83  * The number of TAPs in the __jtag_all_taps list, used to track the
  84  * assigned chain position to new TAPs
  85  */
  86 static unsigned jtag_num_taps = 0;
  87
  88 static enum reset_types jtag_reset_config = RESET_NONE;
  89 static tap_state_t cmd_queue_end_state = TAP_RESET;
  90 tap_state_t cmd_queue_cur_state = TAP_RESET;
  91
  92 static bool jtag_verify_capture_ir = true;
  93 static int jtag_verify = 1;
  94
  95 /* how long the OpenOCD should wait before attempting JTAG communication after reset lines deasserted (in ms) */
  96 static int jtag_nsrst_delay = 0; /* default to no nSRST delay */
  97 static int jtag_ntrst_delay = 0; /* default to no nTRST delay */
  98 static int jtag_nsrst_assert_width = 0; /* width of assertion */
  99 static int jtag_ntrst_assert_width = 0; /* width of assertion */
 100
 101 typedef struct jtag_event_callback_s
 102 {
 103         jtag_event_handler_t          callback;
 104         void*                         priv;
 105         struct jtag_event_callback_s* next;
 106 } jtag_event_callback_t;
 107
 108 /* callbacks to inform high-level handlers about JTAG state changes */
 109 static jtag_event_callback_t *jtag_event_callbacks;
 110
 111 /* speed in kHz*/
 112 static int speed_khz = 0;
 113 /* speed to fallback to when RCLK is requested but not supported */
 114 static int rclk_fallback_speed_khz = 0;
 115 static enum {CLOCK_MODE_SPEED, CLOCK_MODE_KHZ, CLOCK_MODE_RCLK} clock_mode;
 116 static int jtag_speed = 0;
 117
 118 static struct jtag_interface_s *jtag = NULL;
 119
 120 /* configuration */
 121 jtag_interface_t *jtag_interface = NULL;
 122
 123 void jtag_set_error(int error)
 124 {
 125         if ((error == ERROR_OK) || (jtag_error != ERROR_OK))
 126                 return;
 127         jtag_error = error;
 128 }
 129 int jtag_get_error(void)
 130 {
 131         return jtag_error;
 132 }
 133 int jtag_error_clear(void)
 134 {
 135         int temp = jtag_error;
 136         jtag_error = ERROR_OK;
 137         return temp;
 138 }
 139
 140 /************/
 141
 142 static bool jtag_poll = 1;
 143
 144 bool is_jtag_poll_safe(void)
 145 {
 146         /* Polling can be disabled explicitly with set_enabled(false).
 147          * It is also implicitly disabled while TRST is active and
 148          * while SRST is gating the JTAG clock.
 149          */
 150         if (!jtag_poll || jtag_trst != 0)
 151                 return false;
 152         return jtag_srst == 0 || (jtag_reset_config & RESET_SRST_NO_GATING);
 153 }
 154
 155 bool jtag_poll_get_enabled(void)
 156 {
 157         return jtag_poll;
 158 }
 159
 160 void jtag_poll_set_enabled(bool value)
 161 {
 162         jtag_poll = value;
 163 }
 164
 165 /************/
 166
 167 jtag_tap_t *jtag_all_taps(void)
 168 {
 169         return __jtag_all_taps;
 170 };
 171
 172 unsigned jtag_tap_count(void)
 173 {
 174         return jtag_num_taps;
 175 }
 176
 177 unsigned jtag_tap_count_enabled(void)
 178 {
 179         jtag_tap_t *t = jtag_all_taps();
 180         unsigned n = 0;
 181         while (t)
 182         {
 183                 if (t->enabled)
 184                         n++;
 185                 t = t->next_tap;
 186         }
 187         return n;
 188 }
 189
 190 /// Append a new TAP to the chain of all taps.
 191 void jtag_tap_add(struct jtag_tap_s *t)
 192 {
 193         t->abs_chain_position = jtag_num_taps++;
 194
 195         jtag_tap_t **tap = &__jtag_all_taps;
 196         while (*tap != NULL)
 197                 tap = &(*tap)->next_tap;
 198         *tap = t;
 199 }
 200
 201 /* returns a pointer to the n-th device in the scan chain */
 202 static inline jtag_tap_t *jtag_tap_by_position(unsigned n)
 203 {
 204         jtag_tap_t *t = jtag_all_taps();
 205
 206         while (t && n-- > 0)
 207                 t = t->next_tap;
 208
 209         return t;
 210 }
 211
 212 jtag_tap_t *jtag_tap_by_string(const char *s)
 213 {
 214         /* try by name first */
 215         jtag_tap_t *t = jtag_all_taps();
 216
 217         while (t)
 218         {
 219                 if (0 == strcmp(t->dotted_name, s))
 220                         return t;
 221                 t = t->next_tap;
 222         }
 223
 224         /* no tap found by name, so try to parse the name as a number */
 225         unsigned n;
 226         if (parse_uint(s, &n) != ERROR_OK)
 227                 return NULL;
 228
 229         /* FIXME remove this numeric fallback code late June 2010, along
 230          * with all info in the User's Guide that TAPs have numeric IDs.
 231          * Also update "scan_chain" output to not display the numbers.
 232          */
 233         t = jtag_tap_by_position(n);
 234         if (t)
 235                 LOG_WARNING("Specify TAP '%s' by name, not number %u",
 236                         t->dotted_name, n);
 237
 238         return t;
 239 }
 240
 241 jtag_tap_t *jtag_tap_by_jim_obj(Jim_Interp *interp, Jim_Obj *o)
 242 {
 243         const char *cp = Jim_GetString(o, NULL);
 244         jtag_tap_t *t = cp ? jtag_tap_by_string(cp) : NULL;
 245         if (NULL == cp)
 246                 cp = "(unknown)";
 247         if (NULL == t)
 248                 Jim_SetResult_sprintf(interp, "Tap '%s' could not be found", cp);
 249         return t;
 250 }
 251
 252 jtag_tap_t* jtag_tap_next_enabled(jtag_tap_t* p)
 253 {
 254         p = p ? p->next_tap : jtag_all_taps();
 255         while (p)
 256         {
 257                 if (p->enabled)
 258                         return p;
 259                 p = p->next_tap;
 260         }
 261         return NULL;
 262 }
 263
 264 const char *jtag_tap_name(const jtag_tap_t *tap)
 265 {
 266         return (tap == NULL) ? "(unknown)" : tap->dotted_name;
 267 }
 268
 269
 270 int jtag_register_event_callback(jtag_event_handler_t callback, void *priv)
 271 {
 272         jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
 273
 274         if (callback == NULL)
 275         {
 276                 return ERROR_INVALID_ARGUMENTS;
 277         }
 278
 279         if (*callbacks_p)
 280         {
 281                 while ((*callbacks_p)->next)
 282                         callbacks_p = &((*callbacks_p)->next);
 283                 callbacks_p = &((*callbacks_p)->next);
 284         }
 285
 286         (*callbacks_p) = malloc(sizeof(jtag_event_callback_t));
 287         (*callbacks_p)->callback = callback;
 288         (*callbacks_p)->priv = priv;
 289         (*callbacks_p)->next = NULL;
 290
 291         return ERROR_OK;
 292 }
 293
 294 int jtag_unregister_event_callback(jtag_event_handler_t callback, void *priv)
 295 {
 296         jtag_event_callback_t **callbacks_p;
 297         jtag_event_callback_t **next;
 298
 299         if (callback == NULL)
 300         {
 301                 return ERROR_INVALID_ARGUMENTS;
 302         }
 303
 304         for (callbacks_p = &jtag_event_callbacks;
 305                         *callbacks_p != NULL;
 306                         callbacks_p = next)
 307         {
 308                 next = &((*callbacks_p)->next);
 309
 310                 if ((*callbacks_p)->priv != priv)
 311                         continue;
 312
 313                 if ((*callbacks_p)->callback == callback)
 314                 {
 315                         free(*callbacks_p);
 316                         *callbacks_p = *next;
 317                 }
 318         }
 319
 320         return ERROR_OK;
 321 }
 322
 323 int jtag_call_event_callbacks(enum jtag_event event)
 324 {
 325         jtag_event_callback_t *callback = jtag_event_callbacks;
 326
 327         LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
 328
 329         while (callback)
 330         {
 331                 jtag_event_callback_t *next;
 332
 333                 /* callback may remove itself */
 334                 next = callback->next;
 335                 callback->callback(event, callback->priv);
 336                 callback = next;
 337         }
 338
 339         return ERROR_OK;
 340 }
 341
 342 static void jtag_checks(void)
 343 {
 344         assert(jtag_trst == 0);
 345 }
 346
 347 static void jtag_prelude(tap_state_t state)
 348 {
 349         jtag_checks();
 350
 351         assert(state != TAP_INVALID);
 352
 353         cmd_queue_cur_state = state;
 354 }
 355
 356 void jtag_alloc_in_value32(scan_field_t *field)
 357 {
 358         interface_jtag_alloc_in_value32(field);
 359 }
 360
 361 void jtag_add_ir_scan_noverify(int in_count, const scan_field_t *in_fields,
 362                 tap_state_t state)
 363 {
 364         jtag_prelude(state);
 365
 366         int retval = interface_jtag_add_ir_scan(in_count, in_fields, state);
 367         jtag_set_error(retval);
 368 }
 369
 370
 371 void jtag_add_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
 372 {
 373         assert(state != TAP_RESET);
 374
 375         if (jtag_verify && jtag_verify_capture_ir)
 376         {
 377                 /* 8 x 32 bit id's is enough for all invocations */
 378
 379                 for (int j = 0; j < in_num_fields; j++)
 380                 {
 381                         /* if we are to run a verification of the ir scan, we need to get the input back.
 382                          * We may have to allocate space if the caller didn't ask for the input back.
 383                          */
 384                         in_fields[j].check_value = in_fields[j].tap->expected;
 385                         in_fields[j].check_mask = in_fields[j].tap->expected_mask;
 386                 }
 387                 jtag_add_scan_check(jtag_add_ir_scan_noverify, in_num_fields, in_fields, state);
 388         } else
 389         {
 390                 jtag_add_ir_scan_noverify(in_num_fields, in_fields, state);
 391         }
 392 }
 393
 394 void jtag_add_plain_ir_scan(int in_num_fields, const scan_field_t *in_fields,
 395                 tap_state_t state)
 396 {
 397         assert(state != TAP_RESET);
 398
 399         jtag_prelude(state);
 400
 401         int retval = interface_jtag_add_plain_ir_scan(
 402                         in_num_fields, in_fields, state);
 403         jtag_set_error(retval);
 404 }
 405
 406 void jtag_add_callback(jtag_callback1_t f, jtag_callback_data_t data0)
 407 {
 408         interface_jtag_add_callback(f, data0);
 409 }
 410
 411 void jtag_add_callback4(jtag_callback_t f, jtag_callback_data_t data0,
 412                 jtag_callback_data_t data1, jtag_callback_data_t data2,
 413                 jtag_callback_data_t data3)
 414 {
 415         interface_jtag_add_callback4(f, data0, data1, data2, data3);
 416 }
 417
 418 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
 419                 uint8_t *in_check_mask, int num_bits);
 420
 421 static int jtag_check_value_mask_callback(jtag_callback_data_t data0, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
 422 {
 423         return jtag_check_value_inner((uint8_t *)data0, (uint8_t *)data1, (uint8_t *)data2, (int)data3);
 424 }
 425
 426 static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, const scan_field_t *in_fields, tap_state_t state),
 427                 int in_num_fields, scan_field_t *in_fields, tap_state_t state)
 428 {
 429         for (int i = 0; i < in_num_fields; i++)
 430         {
 431                 struct scan_field_s *field = &in_fields[i];
 432                 field->allocated = 0;
 433                 field->modified = 0;
 434                 if (field->check_value || field->in_value)
 435                         continue;
 436                 interface_jtag_add_scan_check_alloc(field);
 437                 field->modified = 1;
 438         }
 439
 440         jtag_add_scan(in_num_fields, in_fields, state);
 441
 442         for (int i = 0; i < in_num_fields; i++)
 443         {
 444                 if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value != NULL))
 445                 {
 446                         /* this is synchronous for a minidriver */
 447                         jtag_add_callback4(jtag_check_value_mask_callback, (jtag_callback_data_t)in_fields[i].in_value,
 448                                 (jtag_callback_data_t)in_fields[i].check_value,
 449                                 (jtag_callback_data_t)in_fields[i].check_mask,
 450                                 (jtag_callback_data_t)in_fields[i].num_bits);
 451                 }
 452                 if (in_fields[i].allocated)
 453                 {
 454                         free(in_fields[i].in_value);
 455                 }
 456                 if (in_fields[i].modified)
 457                 {
 458                         in_fields[i].in_value = NULL;
 459                 }
 460         }
 461 }
 462
 463 void jtag_add_dr_scan_check(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
 464 {
 465         if (jtag_verify)
 466         {
 467                 jtag_add_scan_check(jtag_add_dr_scan, in_num_fields, in_fields, state);
 468         } else
 469         {
 470                 jtag_add_dr_scan(in_num_fields, in_fields, state);
 471         }
 472 }
 473
 474
 475 void jtag_add_dr_scan(int in_num_fields, const scan_field_t *in_fields,
 476                 tap_state_t state)
 477 {
 478         assert(state != TAP_RESET);
 479
 480         jtag_prelude(state);
 481
 482         int retval;
 483         retval = interface_jtag_add_dr_scan(in_num_fields, in_fields, state);
 484         jtag_set_error(retval);
 485 }
 486
 487 void jtag_add_plain_dr_scan(int in_num_fields, const scan_field_t *in_fields,
 488                 tap_state_t state)
 489 {
 490         assert(state != TAP_RESET);
 491
 492         jtag_prelude(state);
 493
 494         int retval;
 495         retval = interface_jtag_add_plain_dr_scan(in_num_fields, in_fields, state);
 496         jtag_set_error(retval);
 497 }
 498
 499 void jtag_add_dr_out(jtag_tap_t* tap,
 500                 int num_fields, const int* num_bits, const uint32_t* value,
 501                 tap_state_t end_state)
 502 {
 503         assert(end_state != TAP_RESET);
 504         assert(end_state != TAP_INVALID);
 505
 506         cmd_queue_cur_state = end_state;
 507
 508         interface_jtag_add_dr_out(tap,
 509                         num_fields, num_bits, value,
 510                         end_state);
 511 }
 512
 513 void jtag_add_tlr(void)
 514 {
 515         jtag_prelude(TAP_RESET);
 516         jtag_set_error(interface_jtag_add_tlr());
 517
 518         /* NOTE: order here matches TRST path in jtag_add_reset() */
 519         jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
 520         jtag_notify_event(JTAG_TRST_ASSERTED);
 521 }
 522
 523 void jtag_add_pathmove(int num_states, const tap_state_t *path)
 524 {
 525         tap_state_t cur_state = cmd_queue_cur_state;
 526
 527         /* the last state has to be a stable state */
 528         if (!tap_is_state_stable(path[num_states - 1]))
 529         {
 530                 LOG_ERROR("BUG: TAP path doesn't finish in a stable state");
 531                 jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
 532                 return;
 533         }
 534
 535         for (int i = 0; i < num_states; i++)
 536         {
 537                 if (path[i] == TAP_RESET)
 538                 {
 539                         LOG_ERROR("BUG: TAP_RESET is not a valid state for pathmove sequences");
 540                         jtag_set_error(ERROR_JTAG_STATE_INVALID);
 541                         return;
 542                 }
 543
 544                 if (tap_state_transition(cur_state, true)  != path[i]
 545                   && tap_state_transition(cur_state, false) != path[i])
 546                 {
 547                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
 548                                         tap_state_name(cur_state), tap_state_name(path[i]));
 549                         jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
 550                         return;
 551                 }
 552                 cur_state = path[i];
 553         }
 554
 555         jtag_checks();
 556
 557         jtag_set_error(interface_jtag_add_pathmove(num_states, path));
 558         cmd_queue_cur_state = path[num_states - 1];
 559 }
 560
 561 int jtag_add_statemove(tap_state_t goal_state)
 562 {
 563         tap_state_t cur_state = cmd_queue_cur_state;
 564
 565         LOG_DEBUG("cur_state=%s goal_state=%s",
 566                 tap_state_name(cur_state),
 567                 tap_state_name(goal_state));
 568
 569
 570         /* If goal is RESET, be paranoid and force that that transition
 571          * (e.g. five TCK cycles, TMS high).  Else trust "cur_state".
 572          */
 573         if (goal_state == TAP_RESET)
 574                 jtag_add_tlr();
 575         else if (goal_state == cur_state)
 576                 /* nothing to do */ ;
 577
 578         else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state))
 579         {
 580                 unsigned tms_bits  = tap_get_tms_path(cur_state, goal_state);
 581                 unsigned tms_count = tap_get_tms_path_len(cur_state, goal_state);
 582                 tap_state_t moves[8];
 583                 assert(tms_count < DIM(moves));
 584
 585                 for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
 586                 {
 587                         bool bit = tms_bits & 1;
 588
 589                         cur_state = tap_state_transition(cur_state, bit);
 590                         moves[i] = cur_state;
 591                 }
 592
 593                 jtag_add_pathmove(tms_count, moves);
 594         }
 595         else if (tap_state_transition(cur_state, true)  == goal_state
 596                 ||   tap_state_transition(cur_state, false) == goal_state)
 597         {
 598                 jtag_add_pathmove(1, &goal_state);
 599         }
 600
 601         else
 602                 return ERROR_FAIL;
 603
 604         return ERROR_OK;
 605 }
 606
 607 void jtag_add_runtest(int num_cycles, tap_state_t state)
 608 {
 609         jtag_prelude(state);
 610         jtag_set_error(interface_jtag_add_runtest(num_cycles, state));
 611 }
 612
 613
 614 void jtag_add_clocks(int num_cycles)
 615 {
 616         if (!tap_is_state_stable(cmd_queue_cur_state))
 617         {
 618                  LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
 619                                  tap_state_name(cmd_queue_cur_state));
 620                  jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
 621                  return;
 622         }
 623
 624         if (num_cycles > 0)
 625         {
 626                 jtag_checks();
 627                 jtag_set_error(interface_jtag_add_clocks(num_cycles));
 628         }
 629 }
 630
 631 void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 632 {
 633         int trst_with_tlr = 0;
 634         int new_srst = 0;
 635         int new_trst = 0;
 636
 637         /* Without SRST, we must use target-specific JTAG operations
 638          * on each target; callers should not be requesting SRST when
 639          * that signal doesn't exist.
 640          *
 641          * RESET_SRST_PULLS_TRST is a board or chip level quirk, which
 642          * can kick in even if the JTAG adapter can't drive TRST.
 643          */
 644         if (req_srst) {
 645                 if (!(jtag_reset_config & RESET_HAS_SRST)) {
 646                         LOG_ERROR("BUG: can't assert SRST");
 647                         jtag_set_error(ERROR_FAIL);
 648                         return;
 649                 }
 650                 if ((jtag_reset_config & RESET_SRST_PULLS_TRST) != 0
 651                                 && !req_tlr_or_trst) {
 652                         LOG_ERROR("BUG: can't assert only SRST");
 653                         jtag_set_error(ERROR_FAIL);
 654                         return;
 655                 }
 656                 new_srst = 1;
 657         }
 658
 659         /* JTAG reset (entry to TAP_RESET state) can always be achieved
 660          * using TCK and TMS; that may go through a TAP_{IR,DR}UPDATE
 661          * state first.  TRST accelerates it, and bypasses those states.
 662          *
 663          * RESET_TRST_PULLS_SRST is a board or chip level quirk, which
 664          * can kick in even if the JTAG adapter can't drive SRST.
 665          */
 666         if (req_tlr_or_trst) {
 667                 if (!(jtag_reset_config & RESET_HAS_TRST))
 668                         trst_with_tlr = 1;
 669                 else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
 670                                 && !req_srst)
 671                         trst_with_tlr = 1;
 672                 else
 673                         new_trst = 1;
 674         }
 675
 676         /* Maybe change TRST and/or SRST signal state */
 677         if (jtag_srst != new_srst || jtag_trst != new_trst) {
 678                 int retval;
 679
 680                 retval = interface_jtag_add_reset(new_trst, new_srst);
 681                 if (retval != ERROR_OK)
 682                         jtag_set_error(retval);
 683                 else
 684                         retval = jtag_execute_queue();
 685
 686                 if (retval != ERROR_OK) {
 687                         LOG_ERROR("TRST/SRST error %d", retval);
 688                         return;
 689                 }
 690         }
 691
 692         /* SRST resets everything hooked up to that signal */
 693         if (jtag_srst != new_srst) {
 694                 jtag_srst = new_srst;
 695                 if (jtag_srst)
 696                 {
 697                         LOG_DEBUG("SRST line asserted");
 698                         if (jtag_nsrst_assert_width)
 699                                 jtag_add_sleep(jtag_nsrst_assert_width * 1000);
 700                 }
 701                 else {
 702                         LOG_DEBUG("SRST line released");
 703                         if (jtag_nsrst_delay)
 704                                 jtag_add_sleep(jtag_nsrst_delay * 1000);
 705                 }
 706         }
 707
 708         /* Maybe enter the JTAG TAP_RESET state ...
 709          *  - using only TMS, TCK, and the JTAG state machine
 710          *  - or else more directly, using TRST
 711          *
 712          * TAP_RESET should be invisible to non-debug parts of the system.
 713          */
 714         if (trst_with_tlr) {
 715                 LOG_DEBUG("JTAG reset with TLR instead of TRST");
 716                 jtag_set_end_state(TAP_RESET);
 717                 jtag_add_tlr();
 718
 719         } else if (jtag_trst != new_trst) {
 720                 jtag_trst = new_trst;
 721                 if (jtag_trst) {
 722                         LOG_DEBUG("TRST line asserted");
 723                         tap_set_state(TAP_RESET);
 724                         if (jtag_ntrst_assert_width)
 725                                 jtag_add_sleep(jtag_ntrst_assert_width * 1000);
 726                 } else {
 727                         LOG_DEBUG("TRST line released");
 728                         if (jtag_ntrst_delay)
 729                                 jtag_add_sleep(jtag_ntrst_delay * 1000);
 730
 731                         /* We just asserted nTRST, so we're now in TAP_RESET.
 732                          * Inform possible listeners about this, now that
 733                          * JTAG instructions and data can be shifted.  This
 734                          * sequence must match jtag_add_tlr().
 735                          */
 736                         jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
 737                         jtag_notify_event(JTAG_TRST_ASSERTED);
 738                 }
 739         }
 740 }
 741
 742 tap_state_t jtag_set_end_state(tap_state_t state)
 743 {
 744         if ((state == TAP_DRSHIFT)||(state == TAP_IRSHIFT))
 745         {
 746                 LOG_ERROR("BUG: TAP_DRSHIFT/IRSHIFT can't be end state. Calling code should use a larger scan field");
 747         }
 748
 749         if (state != TAP_INVALID)
 750                 cmd_queue_end_state = state;
 751         return cmd_queue_end_state;
 752 }
 753
 754 tap_state_t jtag_get_end_state(void)
 755 {
 756         return cmd_queue_end_state;
 757 }
 758
 759 void jtag_add_sleep(uint32_t us)
 760 {
 761         /// @todo Here, keep_alive() appears to be a layering violation!!!
 762         keep_alive();
 763         jtag_set_error(interface_jtag_add_sleep(us));
 764 }
 765
 766 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
 767                 uint8_t *in_check_mask, int num_bits)
 768 {
 769         int retval = ERROR_OK;
 770
 771         int compare_failed = 0;
 772
 773         if (in_check_mask)
 774                 compare_failed = buf_cmp_mask(captured, in_check_value, in_check_mask, num_bits);
 775         else
 776                 compare_failed = buf_cmp(captured, in_check_value, num_bits);
 777
 778         if (compare_failed) {
 779                 char *captured_str, *in_check_value_str;
 780                 int bits = (num_bits > DEBUG_JTAG_IOZ)
 781                                 ? DEBUG_JTAG_IOZ
 782                                 : num_bits;
 783
 784                 /* NOTE:  we've lost diagnostic context here -- 'which tap' */
 785
 786                 captured_str = buf_to_str(captured, bits, 16);
 787                 in_check_value_str = buf_to_str(in_check_value, bits, 16);
 788
 789                 LOG_WARNING("Bad value '%s' captured during DR or IR scan:",
 790                                 captured_str);
 791                 LOG_WARNING(" check_value: 0x%s", in_check_value_str);
 792
 793                 free(captured_str);
 794                 free(in_check_value_str);
 795
 796                 if (in_check_mask) {
 797                         char *in_check_mask_str;
 798
 799                         in_check_mask_str = buf_to_str(in_check_mask, bits, 16);
 800                         LOG_WARNING(" check_mask: 0x%s", in_check_mask_str);
 801                         free(in_check_mask_str);
 802                 }
 803
 804                 retval = ERROR_JTAG_QUEUE_FAILED;
 805         }
 806         return retval;
 807 }
 808
 809 void jtag_check_value_mask(scan_field_t *field, uint8_t *value, uint8_t *mask)
 810 {
 811         assert(field->in_value != NULL);
 812
 813         if (value == NULL)
 814         {
 815                 /* no checking to do */
 816                 return;
 817         }
 818
 819         jtag_execute_queue_noclear();
 820
 821         int retval = jtag_check_value_inner(field->in_value, value, mask, field->num_bits);
 822         jtag_set_error(retval);
 823 }
 824
 825
 826
 827 int default_interface_jtag_execute_queue(void)
 828 {
 829         if (NULL == jtag)
 830         {
 831                 LOG_ERROR("No JTAG interface configured yet.  "
 832                         "Issue 'init' command in startup scripts "
 833                         "before communicating with targets.");
 834                 return ERROR_FAIL;
 835         }
 836
 837         return jtag->execute_queue();
 838 }
 839
 840 void jtag_execute_queue_noclear(void)
 841 {
 842         jtag_flush_queue_count++;
 843         jtag_set_error(interface_jtag_execute_queue());
 844 }
 845
 846 int jtag_get_flush_queue_count(void)
 847 {
 848         return jtag_flush_queue_count;
 849 }
 850
 851 int jtag_execute_queue(void)
 852 {
 853         jtag_execute_queue_noclear();
 854         return jtag_error_clear();
 855 }
 856
 857 static int jtag_reset_callback(enum jtag_event event, void *priv)
 858 {
 859         jtag_tap_t *tap = priv;
 860
 861         if (event == JTAG_TRST_ASSERTED)
 862         {
 863                 tap->enabled = !tap->disabled_after_reset;
 864
 865                 /* current instruction is either BYPASS or IDCODE */
 866                 buf_set_ones(tap->cur_instr, tap->ir_length);
 867                 tap->bypass = 1;
 868         }
 869
 870         return ERROR_OK;
 871 }
 872
 873 void jtag_sleep(uint32_t us)
 874 {
 875         alive_sleep(us/1000);
 876 }
 877
 878 /* Maximum number of enabled JTAG devices we expect in the scan chain,
 879  * plus one (to detect garbage at the end).  Devices that don't support
 880  * IDCODE take up fewer bits, possibly allowing a few more devices.
 881  */
 882 #define JTAG_MAX_CHAIN_SIZE 20
 883
 884 #define EXTRACT_MFG(X)  (((X) & 0xffe) >> 1)
 885 #define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
 886 #define EXTRACT_VER(X)  (((X) & 0xf0000000) >> 28)
 887
 888 /* A reserved manufacturer ID is used in END_OF_CHAIN_FLAG, so we
 889  * know that no valid TAP will have it as an IDCODE value.
 890  */
 891 #define END_OF_CHAIN_FLAG       0x000000ff
 892
 893 static int jtag_examine_chain_execute(uint8_t *idcode_buffer, unsigned num_idcode)
 894 {
 895         scan_field_t field = {
 896                         .tap = NULL,
 897                         .num_bits = num_idcode * 32,
 898                         .out_value = idcode_buffer,
 899                         .in_value = idcode_buffer,
 900                 };
 901
 902         // initialize to the end of chain ID value
 903         for (unsigned i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
 904                 buf_set_u32(idcode_buffer, i * 32, 32, END_OF_CHAIN_FLAG);
 905
 906         jtag_add_plain_dr_scan(1, &field, TAP_DRPAUSE);
 907         jtag_add_tlr();
 908         return jtag_execute_queue();
 909 }
 910
 911 static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
 912 {
 913         uint8_t zero_check = 0x0;
 914         uint8_t one_check = 0xff;
 915
 916         for (unsigned i = 0; i < count * 4; i++)
 917         {
 918                 zero_check |= idcodes[i];
 919                 one_check &= idcodes[i];
 920         }
 921
 922         /* if there wasn't a single non-zero bit or if all bits were one,
 923          * the scan is not valid.  We wrote a mix of both values; either
 924          *
 925          *  - There's a hardware issue (almost certainly):
 926          *     + all-zeroes can mean a target stuck in JTAG reset
 927          *     + all-ones tends to mean no target
 928          *  - The scan chain is WAY longer than we can handle, *AND* either
 929          *     + there are several hundreds of TAPs in bypass, or
 930          *     + at least a few dozen TAPs all have an all-ones IDCODE
 931          */
 932         if (zero_check == 0x00 || one_check == 0xff)
 933         {
 934                 LOG_ERROR("JTAG scan chain interrogation failed: all %s",
 935                                 (zero_check == 0x00) ? "zeroes" : "ones");
 936                 LOG_ERROR("Check JTAG interface, timings, target power, etc.");
 937                 return false;
 938         }
 939         return true;
 940 }
 941
 942 static void jtag_examine_chain_display(enum log_levels level, const char *msg,
 943                 const char *name, uint32_t idcode)
 944 {
 945         log_printf_lf(level, __FILE__, __LINE__, __FUNCTION__,
 946                                   "JTAG tap: %s %16.16s: 0x%08x "
 947                                   "(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
 948                                   name, msg,
 949                                   (unsigned int)idcode,
 950                                   (unsigned int)EXTRACT_MFG(idcode),
 951                                   (unsigned int)EXTRACT_PART(idcode),
 952                                   (unsigned int)EXTRACT_VER(idcode));
 953 }
 954
 955 static bool jtag_idcode_is_final(uint32_t idcode)
 956 {
 957         /*
 958          * Some devices, such as AVR8, will output all 1's instead
 959          * of TDI input value at end of chain.  Allow those values
 960          * instead of failing.
 961          */
 962         return idcode == END_OF_CHAIN_FLAG || idcode == 0xFFFFFFFF;
 963 }
 964
 965 /**
 966  * This helper checks that remaining bits in the examined chain data are
 967  * all as expected, but a single JTAG device requires only 64 bits to be
 968  * read back correctly.  This can help identify and diagnose problems
 969  * with the JTAG chain earlier, gives more helpful/explicit error messages.
 970  * Returns TRUE iff garbage was found.
 971  */
 972 static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned max)
 973 {
 974         bool triggered = false;
 975         for (; count < max - 31; count += 32)
 976         {
 977                 uint32_t idcode = buf_get_u32(idcodes, count, 32);
 978
 979                 /* do not trigger the warning if the data looks good */
 980                 if (jtag_idcode_is_final(idcode))
 981                         continue;
 982                 LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
 983                                         count, (unsigned int)idcode);
 984                 triggered = true;
 985         }
 986         return triggered;
 987 }
 988
 989 static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
 990 {
 991         /* ignore expected BYPASS codes; warn otherwise */
 992         if (0 == tap->expected_ids_cnt && !tap->idcode)
 993                 return true;
 994
 995         /* Loop over the expected identification codes and test for a match */
 996         unsigned ii, limit = tap->expected_ids_cnt;
 997
 998         for (ii = 0; ii < limit; ii++)
 999         {
1000                 if (tap->idcode == tap->expected_ids[ii])
1001                         return true;
1002
1003                 /* treat "-expected-id 0" as a "don't-warn" wildcard */
1004                 if (0 == tap->expected_ids[ii])
1005                         return true;
1006         }
1007
1008         /* If none of the expected ids matched, warn */
1009         jtag_examine_chain_display(LOG_LVL_WARNING, "UNEXPECTED",
1010                         tap->dotted_name, tap->idcode);
1011         for (ii = 0; ii < limit; ii++)
1012         {
1013                 char msg[32];
1014
1015                 snprintf(msg, sizeof(msg), "expected %u of %u", ii + 1, limit);
1016                 jtag_examine_chain_display(LOG_LVL_ERROR, msg,
1017                                 tap->dotted_name, tap->expected_ids[ii]);
1018         }
1019         return false;
1020 }
1021
1022 /* Try to examine chain layout according to IEEE 1149.1 §12
1023  * This is called a "blind interrogation" of the scan chain.
1024  */
1025 static int jtag_examine_chain(void)
1026 {
1027         uint8_t idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
1028         unsigned bit_count;
1029         int retval;
1030
1031         /* DR scan to collect BYPASS or IDCODE register contents.
1032          * Then make sure the scan data has both ones and zeroes.
1033          */
1034         LOG_DEBUG("DR scan interrogation for IDCODE/BYPASS");
1035         retval = jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
1036         if (retval != ERROR_OK)
1037                 return retval;
1038         if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
1039                 return ERROR_JTAG_INIT_FAILED;
1040
1041         /* point at the 1st tap */
1042         jtag_tap_t *tap = jtag_tap_next_enabled(NULL);
1043         if (tap == NULL)
1044         {
1045                 LOG_ERROR("JTAG: No taps enabled?");
1046                 return ERROR_JTAG_INIT_FAILED;
1047         }
1048
1049         for (bit_count = 0;
1050                         tap && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;
1051                         tap = jtag_tap_next_enabled(tap))
1052         {
1053                 uint32_t idcode = buf_get_u32(idcode_buffer, bit_count, 32);
1054
1055                 if ((idcode & 1) == 0)
1056                 {
1057                         /* Zero for LSB indicates a device in bypass */
1058                         LOG_WARNING("TAP %s does not have IDCODE",
1059                                         tap->dotted_name);
1060                         idcode = 0;
1061                         tap->hasidcode = false;
1062
1063                         bit_count += 1;
1064                 }
1065                 else
1066                 {
1067                         /* Friendly devices support IDCODE */
1068                         tap->hasidcode = true;
1069                         jtag_examine_chain_display(LOG_LVL_INFO,
1070                                         "tap/device found",
1071                                         tap->dotted_name, idcode);
1072
1073                         bit_count += 32;
1074                 }
1075                 tap->idcode = idcode;
1076
1077                 /* ensure the TAP ID matches what was expected */
1078                 if (!jtag_examine_chain_match_tap(tap))
1079                         retval = ERROR_JTAG_INIT_SOFT_FAIL;
1080         }
1081
1082         /* Fail if too many TAPs were enabled for us to verify them all. */
1083         if (tap) {
1084                 LOG_ERROR("Too many TAPs enabled; '%s' ignored.",
1085                                 tap->dotted_name);
1086                 return ERROR_JTAG_INIT_FAILED;
1087         }
1088
1089         /* After those IDCODE or BYPASS register values should be
1090          * only the data we fed into the scan chain.
1091          */
1092         if (jtag_examine_chain_end(idcode_buffer, bit_count,
1093                         8 * sizeof(idcode_buffer))) {
1094                 LOG_ERROR("double-check your JTAG setup (interface, "
1095                                 "speed, missing TAPs, ...)");
1096                 return ERROR_JTAG_INIT_FAILED;
1097         }
1098
1099         /* Return success or, for backwards compatibility if only
1100          * some IDCODE values mismatched, a soft/continuable fault.
1101          */
1102         return retval;
1103 }
1104
1105 /*
1106  * Validate the date loaded by entry to the Capture-IR state, to help
1107  * find errors related to scan chain configuration (wrong IR lengths)
1108  * or communication.
1109  *
1110  * Entry state can be anything.  On non-error exit, all TAPs are in
1111  * bypass mode.  On error exits, the scan chain is reset.
1112  */
1113 static int jtag_validate_ircapture(void)
1114 {
1115         jtag_tap_t *tap;
1116         int total_ir_length = 0;
1117         uint8_t *ir_test = NULL;
1118         scan_field_t field;
1119         int val;
1120         int chain_pos = 0;
1121         int retval;
1122
1123         for (tap = NULL, total_ir_length = 0;
1124                         (tap = jtag_tap_next_enabled(tap)) != NULL;
1125                         total_ir_length += tap->ir_length)
1126                 continue;
1127
1128         /* increase length to add 2 bit sentinel after scan */
1129         total_ir_length += 2;
1130
1131         ir_test = malloc(CEIL(total_ir_length, 8));
1132         if (ir_test == NULL)
1133                 return ERROR_FAIL;
1134
1135         /* after this scan, all TAPs will capture BYPASS instructions */
1136         buf_set_ones(ir_test, total_ir_length);
1137
1138         field.tap = NULL;
1139         field.num_bits = total_ir_length;
1140         field.out_value = ir_test;
1141         field.in_value = ir_test;
1142
1143         jtag_add_plain_ir_scan(1, &field, TAP_IDLE);
1144
1145         LOG_DEBUG("IR capture validation scan");
1146         retval = jtag_execute_queue();
1147         if (retval != ERROR_OK)
1148                 goto done;
1149
1150         tap = NULL;
1151         chain_pos = 0;
1152
1153         for (;;) {
1154                 tap = jtag_tap_next_enabled(tap);
1155                 if (tap == NULL) {
1156                         break;
1157                 }
1158
1159                 /* Validate the two LSBs, which must be 01 per JTAG spec.
1160                  *
1161                  * Or ... more bits could be provided by TAP declaration.
1162                  * Plus, some taps (notably in i.MX series chips) violate
1163                  * this part of the JTAG spec, so their capture mask/value
1164                  * attributes might disable this test.
1165                  */
1166                 val = buf_get_u32(ir_test, chain_pos, tap->ir_length);
1167                 if ((val & tap->ir_capture_mask) != tap->ir_capture_value) {
1168                         LOG_ERROR("%s: IR capture error; saw 0x%0*x not 0x%0*x",
1169                                         jtag_tap_name(tap),
1170                                         (tap->ir_length + 7) / tap->ir_length,
1171                                         val,
1172                                         (tap->ir_length + 7) / tap->ir_length,
1173                                         (unsigned) tap->ir_capture_value);
1174
1175                         retval = ERROR_JTAG_INIT_FAILED;
1176                         goto done;
1177                 }
1178                 LOG_DEBUG("%s: IR capture 0x%0*x", jtag_tap_name(tap),
1179                                 (tap->ir_length + 7) / tap->ir_length, val);
1180                 chain_pos += tap->ir_length;
1181         }
1182
1183         /* verify the '11' sentinel we wrote is returned at the end */
1184         val = buf_get_u32(ir_test, chain_pos, 2);
1185         if (val != 0x3)
1186         {
1187                 char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
1188
1189                 LOG_ERROR("IR capture error at bit %d, saw 0x%s not 0x...3",
1190                                 chain_pos, cbuf);
1191                 free(cbuf);
1192                 retval = ERROR_JTAG_INIT_FAILED;
1193         }
1194
1195 done:
1196         free(ir_test);
1197         if (retval != ERROR_OK) {
1198                 jtag_add_tlr();
1199                 jtag_execute_queue();
1200         }
1201         return retval;
1202 }
1203
1204
1205 void jtag_tap_init(jtag_tap_t *tap)
1206 {
1207         unsigned ir_len_bits;
1208         unsigned ir_len_bytes;
1209
1210         assert(0 != tap->ir_length);
1211
1212         ir_len_bits = tap->ir_length;
1213         ir_len_bytes = CEIL(ir_len_bits, 8);
1214
1215         tap->expected = calloc(1, ir_len_bytes);
1216         tap->expected_mask = calloc(1, ir_len_bytes);
1217         tap->cur_instr = malloc(ir_len_bytes);
1218
1219         /// @todo cope better with ir_length bigger than 32 bits
1220         if (ir_len_bits > 32)
1221                 ir_len_bits = 32;
1222
1223         buf_set_u32(tap->expected, 0, ir_len_bits, tap->ir_capture_value);
1224         buf_set_u32(tap->expected_mask, 0, ir_len_bits, tap->ir_capture_mask);
1225
1226         // TAP will be in bypass mode after jtag_validate_ircapture()
1227         tap->bypass = 1;
1228         buf_set_ones(tap->cur_instr, tap->ir_length);
1229
1230         // register the reset callback for the TAP
1231         jtag_register_event_callback(&jtag_reset_callback, tap);
1232
1233         LOG_DEBUG("Created Tap: %s @ abs position %d, "
1234                         "irlen %d, capture: 0x%x mask: 0x%x", tap->dotted_name,
1235                                 tap->abs_chain_position, tap->ir_length,
1236                                 (unsigned) tap->ir_capture_value,
1237                                 (unsigned) tap->ir_capture_mask);
1238         jtag_tap_add(tap);
1239 }
1240
1241 void jtag_tap_free(jtag_tap_t *tap)
1242 {
1243         jtag_unregister_event_callback(&jtag_reset_callback, tap);
1244
1245         /// @todo is anything missing? no memory leaks please
1246         free((void *)tap->expected);
1247         free((void *)tap->expected_ids);
1248         free((void *)tap->chip);
1249         free((void *)tap->tapname);
1250         free((void *)tap->dotted_name);
1251         free(tap);
1252 }
1253
1254 int jtag_interface_init(struct command_context_s *cmd_ctx)
1255 {
1256         if (jtag)
1257                 return ERROR_OK;
1258
1259         if (!jtag_interface)
1260         {
1261                 /* nothing was previously specified by "interface" command */
1262                 LOG_ERROR("JTAG interface has to be specified, see \"interface\" command");
1263                 return ERROR_JTAG_INVALID_INTERFACE;
1264         }
1265
1266         jtag = jtag_interface;
1267         if (jtag_interface->init() != ERROR_OK)
1268         {
1269                 jtag = NULL;
1270                 return ERROR_JTAG_INIT_FAILED;
1271         }
1272
1273         int requested_khz = jtag_get_speed_khz();
1274         int actual_khz = requested_khz;
1275         int retval = jtag_get_speed_readable(&actual_khz);
1276         if (ERROR_OK != retval)
1277                 LOG_INFO("interface specific clock speed value %d", jtag_get_speed());
1278         else if (actual_khz)
1279         {
1280                 if ((CLOCK_MODE_RCLK == clock_mode)
1281                         || ((CLOCK_MODE_KHZ == clock_mode) && !requested_khz))
1282                 {
1283                         LOG_INFO("RCLK (adaptive clock speed) not supported - fallback to %d kHz"
1284                                 , actual_khz);
1285                 }
1286                 else
1287                         LOG_INFO("clock speed %d kHz", actual_khz);
1288         }
1289         else
1290                 LOG_INFO("RCLK (adaptive clock speed)");
1291
1292         return ERROR_OK;
1293 }
1294
1295 int jtag_init_inner(struct command_context_s *cmd_ctx)
1296 {
1297         jtag_tap_t *tap;
1298         int retval;
1299         bool issue_setup = true;
1300
1301         LOG_DEBUG("Init JTAG chain");
1302
1303         tap = jtag_tap_next_enabled(NULL);
1304         if (tap == NULL) {
1305                 LOG_ERROR("There are no enabled taps?");
1306                 return ERROR_JTAG_INIT_FAILED;
1307         }
1308
1309         jtag_add_tlr();
1310         if ((retval = jtag_execute_queue()) != ERROR_OK)
1311                 return retval;
1312
1313         /* Examine DR values first.  This discovers problems which will
1314          * prevent communication ... hardware issues like TDO stuck, or
1315          * configuring the wrong number of (enabled) TAPs.
1316          */
1317         retval = jtag_examine_chain();
1318         switch (retval) {
1319         case ERROR_OK:
1320                 /* complete success */
1321                 break;
1322         case ERROR_JTAG_INIT_SOFT_FAIL:
1323                 /* For backward compatibility reasons, try coping with
1324                  * configuration errors involving only ID mismatches.
1325                  * We might be able to talk to the devices.
1326                  */
1327                 LOG_ERROR("Trying to use configured scan chain anyway...");
1328                 issue_setup = false;
1329                 break;
1330         default:
1331                 /* some hard error; already issued diagnostics */
1332                 return retval;
1333         }
1334
1335         /* Now look at IR values.  Problems here will prevent real
1336          * communication.  They mostly mean that the IR length is
1337          * wrong ... or that the IR capture value is wrong.  (The
1338          * latter is uncommon, but easily worked around:  provide
1339          * ircapture/irmask values during TAP setup.)
1340          */
1341         retval = jtag_validate_ircapture();
1342         if (retval != ERROR_OK)
1343                 return retval;
1344
1345         if (issue_setup)
1346                 jtag_notify_event(JTAG_TAP_EVENT_SETUP);
1347         else
1348                 LOG_WARNING("Bypassing JTAG setup events due to errors");
1349
1350
1351         return ERROR_OK;
1352 }
1353
1354 int jtag_interface_quit(void)
1355 {
1356         if (!jtag || !jtag->quit)
1357                 return ERROR_OK;
1358
1359         // close the JTAG interface
1360         int result = jtag->quit();
1361         if (ERROR_OK != result)
1362                 LOG_ERROR("failed: %d", result);
1363
1364         return ERROR_OK;
1365 }
1366
1367
1368 int jtag_init_reset(struct command_context_s *cmd_ctx)
1369 {
1370         int retval;
1371
1372         if ((retval = jtag_interface_init(cmd_ctx)) != ERROR_OK)
1373                 return retval;
1374
1375         LOG_DEBUG("Initializing with hard TRST+SRST reset");
1376
1377         /*
1378          * This procedure is used by default when OpenOCD triggers a reset.
1379          * It's now done through an overridable Tcl "init_reset" wrapper.
1380          *
1381          * This started out as a more powerful "get JTAG working" reset than
1382          * jtag_init_inner(), applying TRST because some chips won't activate
1383          * JTAG without a TRST cycle (presumed to be async, though some of
1384          * those chips synchronize JTAG activation using TCK).
1385          *
1386          * But some chips only activate JTAG as part of an SRST cycle; SRST
1387          * got mixed in.  So it became a hard reset routine, which got used
1388          * in more places, and which coped with JTAG reset being forced as
1389          * part of SRST (srst_pulls_trst).
1390          *
1391          * And even more corner cases started to surface:  TRST and/or SRST
1392          * assertion timings matter; some chips need other JTAG operations;
1393          * TRST/SRST sequences can need to be different from these, etc.
1394          *
1395          * Systems should override that wrapper to support system-specific
1396          * requirements that this not-fully-generic code doesn't handle.
1397          *
1398          * REVISIT once Tcl code can read the reset_config modes, this won't
1399          * need to be a C routine at all...
1400          */
1401         jtag_add_reset(1, 0); /* TAP_RESET, using TMS+TCK or TRST */
1402         if (jtag_reset_config & RESET_HAS_SRST)
1403         {
1404                 jtag_add_reset(1, 1);
1405                 if ((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0)
1406                         jtag_add_reset(0, 1);
1407         }
1408         jtag_add_reset(0, 0);
1409         if ((retval = jtag_execute_queue()) != ERROR_OK)
1410                 return retval;
1411
1412         /* Check that we can communication on the JTAG chain + eventually we want to
1413          * be able to perform enumeration only after OpenOCD has started
1414          * telnet and GDB server
1415          *
1416          * That would allow users to more easily perform any magic they need to before
1417          * reset happens.
1418          */
1419         return jtag_init_inner(cmd_ctx);
1420 }
1421
1422 int jtag_init(struct command_context_s *cmd_ctx)
1423 {
1424         int retval;
1425
1426         if ((retval = jtag_interface_init(cmd_ctx)) != ERROR_OK)
1427                 return retval;
1428
1429         /* guard against oddball hardware: force resets to be inactive */
1430         jtag_add_reset(0, 0);
1431         if ((retval = jtag_execute_queue()) != ERROR_OK)
1432                 return retval;
1433
1434         if (Jim_Eval_Named(interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
1435                 return ERROR_FAIL;
1436
1437         return ERROR_OK;
1438 }
1439
1440 unsigned jtag_get_speed_khz(void)
1441 {
1442         return speed_khz;
1443 }
1444
1445 static int jtag_khz_to_speed(unsigned khz, int* speed)
1446 {
1447         LOG_DEBUG("convert khz to interface specific speed value");
1448         speed_khz = khz;
1449         if (jtag != NULL)
1450         {
1451                 LOG_DEBUG("have interface set up");
1452                 int speed_div1;
1453                 int retval = jtag->khz(jtag_get_speed_khz(), &speed_div1);
1454                 if (ERROR_OK != retval)
1455                 {
1456                         return retval;
1457                 }
1458                 *speed = speed_div1;
1459         }
1460         return ERROR_OK;
1461 }
1462
1463 static int jtag_rclk_to_speed(unsigned fallback_speed_khz, int* speed)
1464 {
1465         int retval = jtag_khz_to_speed(0, speed);
1466         if ((ERROR_OK != retval) && fallback_speed_khz)
1467         {
1468                 LOG_DEBUG("trying fallback speed...");
1469                 retval = jtag_khz_to_speed(fallback_speed_khz, speed);
1470         }
1471         return retval;
1472 }
1473
1474 static int jtag_set_speed(int speed)
1475 {
1476         jtag_speed = speed;
1477         /* this command can be called during CONFIG,
1478          * in which case jtag isn't initialized */
1479         return jtag ? jtag->speed(speed) : ERROR_OK;
1480 }
1481
1482 int jtag_config_speed(int speed)
1483 {
1484         LOG_DEBUG("handle jtag speed");
1485         clock_mode = CLOCK_MODE_SPEED;
1486         return jtag_set_speed(speed);
1487 }
1488
1489 int jtag_config_khz(unsigned khz)
1490 {
1491         LOG_DEBUG("handle jtag khz");
1492         clock_mode = CLOCK_MODE_KHZ;
1493         int speed = 0;
1494         int retval = jtag_khz_to_speed(khz, &speed);
1495         return (ERROR_OK != retval) ? retval : jtag_set_speed(speed);
1496 }
1497
1498 int jtag_config_rclk(unsigned fallback_speed_khz)
1499 {
1500         LOG_DEBUG("handle jtag rclk");
1501         clock_mode = CLOCK_MODE_RCLK;
1502         rclk_fallback_speed_khz = fallback_speed_khz;
1503         int speed = 0;
1504         int retval = jtag_rclk_to_speed(fallback_speed_khz, &speed);
1505         return (ERROR_OK != retval) ? retval : jtag_set_speed(speed);
1506 }
1507
1508 int jtag_get_speed(void)
1509 {
1510         int speed;
1511         switch(clock_mode)
1512         {
1513                 case CLOCK_MODE_SPEED:
1514                         speed = jtag_speed;
1515                         break;
1516                 case CLOCK_MODE_KHZ:
1517                         jtag_khz_to_speed(jtag_get_speed_khz(), &speed);
1518                         break;
1519                 case CLOCK_MODE_RCLK:
1520                         jtag_rclk_to_speed(rclk_fallback_speed_khz, &speed);
1521                         break;
1522                 default:
1523                         LOG_ERROR("BUG: unknown jtag clock mode");
1524                         speed = 0;
1525                         break;
1526         }
1527         return speed;
1528 }
1529
1530 int jtag_get_speed_readable(int *khz)
1531 {
1532         return jtag ? jtag->speed_div(jtag_get_speed(), khz) : ERROR_OK;
1533 }
1534
1535 void jtag_set_verify(bool enable)
1536 {
1537         jtag_verify = enable;
1538 }
1539
1540 bool jtag_will_verify()
1541 {
1542         return jtag_verify;
1543 }
1544
1545 void jtag_set_verify_capture_ir(bool enable)
1546 {
1547         jtag_verify_capture_ir = enable;
1548 }
1549
1550 bool jtag_will_verify_capture_ir()
1551 {
1552         return jtag_verify_capture_ir;
1553 }
1554
1555 int jtag_power_dropout(int *dropout)
1556 {
1557         return jtag->power_dropout(dropout);
1558 }
1559
1560 int jtag_srst_asserted(int *srst_asserted)
1561 {
1562         return jtag->srst_asserted(srst_asserted);
1563 }
1564
1565 enum reset_types jtag_get_reset_config(void)
1566 {
1567         return jtag_reset_config;
1568 }
1569 void jtag_set_reset_config(enum reset_types type)
1570 {
1571         jtag_reset_config = type;
1572 }
1573
1574 int jtag_get_trst(void)
1575 {
1576         return jtag_trst;
1577 }
1578 int jtag_get_srst(void)
1579 {
1580         return jtag_srst;
1581 }
1582
1583 void jtag_set_nsrst_delay(unsigned delay)
1584 {
1585         jtag_nsrst_delay = delay;
1586 }
1587 unsigned jtag_get_nsrst_delay(void)
1588 {
1589         return jtag_nsrst_delay;
1590 }
1591 void jtag_set_ntrst_delay(unsigned delay)
1592 {
1593         jtag_ntrst_delay = delay;
1594 }
1595 unsigned jtag_get_ntrst_delay(void)
1596 {
1597         return jtag_ntrst_delay;
1598 }
1599
1600
1601 void jtag_set_nsrst_assert_width(unsigned delay)
1602 {
1603         jtag_nsrst_assert_width = delay;
1604 }
1605 unsigned jtag_get_nsrst_assert_width(void)
1606 {
1607         return jtag_nsrst_assert_width;
1608 }
1609 void jtag_set_ntrst_assert_width(unsigned delay)
1610 {
1611         jtag_ntrst_assert_width = delay;
1612 }
1613 unsigned jtag_get_ntrst_assert_width(void)
1614 {
1615         return jtag_ntrst_assert_width;
1616 }