src/target/adi_v5_jtag.c

   1 /***************************************************************************
   2  *   Copyright (C) 2006 by Magnus Lundin
   3  *   lundin@mlu.mine.nu
   4  *
   5  *   Copyright (C) 2008 by Spencer Oliver
   6  *   spen@spen-soft.co.uk
   7  *
   8  *   Copyright (C) 2009 by Oyvind Harboe
   9  *   oyvind.harboe@zylin.com
  10  *
  11  *   Copyright (C) 2009-2010 by David Brownell
  12  *
  13  *   This program is free software; you can redistribute it and/or modify
  14  *   it under the terms of the GNU General Public License as published by
  15  *   the Free Software Foundation; either version 2 of the License, or
  16  *   (at your option) any later version.
  17  *
  18  *   This program is distributed in the hope that it will be useful,
  19  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *   GNU General Public License for more details.
  22  *
  23  *   You should have received a copy of the GNU General Public License
  24  *   along with this program; if not, write to the
  25  *   Free Software Foundation, Inc.,
  26  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  27  ***************************************************************************/
  28
  29 /**
  30  * @file
  31  * This file implements JTAG transport support for cores implementing
  32  the ARM Debug Interface version 5 (ADIv5).
  33  */
  34
  35 #ifdef HAVE_CONFIG_H
  36 #include "config.h"
  37 #endif
  38
  39 #include "arm.h"
  40 #include "arm_adi_v5.h"
  41 #include <helper/time_support.h>
  42
  43
  44 /* JTAG instructions/registers for JTAG-DP and SWJ-DP */
  45 #define JTAG_DP_ABORT           0x8
  46 #define JTAG_DP_DPACC           0xA
  47 #define JTAG_DP_APACC           0xB
  48 #define JTAG_DP_IDCODE          0xE
  49
  50 /* three-bit ACK values for DPACC and APACC reads */
  51 #define JTAG_ACK_OK_FAULT       0x2
  52 #define JTAG_ACK_WAIT           0x1
  53
  54 /***************************************************************************
  55  *
  56  * DPACC and APACC scanchain access through JTAG-DP (or SWJ-DP)
  57  *
  58 ***************************************************************************/
  59
  60 /**
  61  * Scan DPACC or APACC using target ordered uint8_t buffers.  No endianness
  62  * conversions are performed.  See section 4.4.3 of the ADIv5 spec, which
  63  * discusses operations which access these registers.
  64  *
  65  * Note that only one scan is performed.  If RnW is set, a separate scan
  66  * will be needed to collect the data which was read; the "invalue" collects
  67  * the posted result of a preceding operation, not the current one.
  68  *
  69  * @param dap the DAP
  70  * @param instr JTAG_DP_APACC (AP access) or JTAG_DP_DPACC (DP access)
  71  * @param reg_addr two significant bits; A[3:2]; for APACC access, the
  72  *      SELECT register has more addressing bits.
  73  * @param RnW false iff outvalue will be written to the DP or AP
  74  * @param outvalue points to a 32-bit (little-endian) integer
  75  * @param invalue NULL, or points to a 32-bit (little-endian) integer
  76  * @param ack points to where the three bit JTAG_ACK_* code will be stored
  77  */
  78
  79 /* FIXME don't export ... this is a temporary workaround for the
  80  * mem_ap_read_buf_u32() mess, until it's no longer JTAG-specific.
  81  */
  82 int adi_jtag_dp_scan(struct adiv5_dap *dap,
  83                 uint8_t instr, uint8_t reg_addr, uint8_t RnW,
  84                 uint8_t *outvalue, uint8_t *invalue, uint8_t *ack)
  85 {
  86         struct arm_jtag *jtag_info = dap->jtag_info;
  87         struct scan_field fields[2];
  88         uint8_t out_addr_buf;
  89
  90         arm_jtag_set_instr(jtag_info, instr, NULL, TAP_IDLE);
  91
  92         /* Scan out a read or write operation using some DP or AP register.
  93          * For APACC access with any sticky error flag set, this is discarded.
  94          */
  95         fields[0].num_bits = 3;
  96         buf_set_u32(&out_addr_buf, 0, 3, ((reg_addr >> 1) & 0x6) | (RnW & 0x1));
  97         fields[0].out_value = &out_addr_buf;
  98         fields[0].in_value = ack;
  99
 100         /* NOTE: if we receive JTAG_ACK_WAIT, the previous operation did not
 101          * complete; data we write is discarded, data we read is unpredictable.
 102          * When overrun detect is active, STICKYORUN is set.
 103          */
 104
 105         fields[1].num_bits = 32;
 106         fields[1].out_value = outvalue;
 107         fields[1].in_value = invalue;
 108
 109         jtag_add_dr_scan(jtag_info->tap, 2, fields, TAP_IDLE);
 110
 111         /* Add specified number of tck clocks after starting memory bus
 112          * access, giving the hardware time to complete the access.
 113          * They provide more time for the (MEM) AP to complete the read ...
 114          * See "Minimum Response Time" for JTAG-DP, in the ADIv5 spec.
 115          */
 116         if ((instr == JTAG_DP_APACC)
 117                         && ((reg_addr == AP_REG_DRW)
 118                                 || ((reg_addr & 0xF0) == AP_REG_BD0))
 119                         && (dap->memaccess_tck != 0))
 120                 jtag_add_runtest(dap->memaccess_tck,
 121                                 TAP_IDLE);
 122
 123         return jtag_get_error();
 124 }
 125
 126 /**
 127  * Scan DPACC or APACC out and in from host ordered uint32_t buffers.
 128  * This is exactly like adi_jtag_dp_scan(), except that endianness
 129  * conversions are performed (so the types of invalue and outvalue
 130  * must be different).
 131  */
 132 static int adi_jtag_dp_scan_u32(struct adiv5_dap *dap,
 133                 uint8_t instr, uint8_t reg_addr, uint8_t RnW,
 134                 uint32_t outvalue, uint32_t *invalue, uint8_t *ack)
 135 {
 136         uint8_t out_value_buf[4];
 137         int retval;
 138
 139         buf_set_u32(out_value_buf, 0, 32, outvalue);
 140
 141         retval = adi_jtag_dp_scan(dap, instr, reg_addr, RnW,
 142                         out_value_buf, (uint8_t *)invalue, ack);
 143         if (retval != ERROR_OK)
 144                 return retval;
 145
 146         if (invalue)
 147                 jtag_add_callback(arm_le_to_h_u32,
 148                                 (jtag_callback_data_t) invalue);
 149
 150         return retval;
 151 }
 152
 153 /**
 154  * Utility to write AP registers.
 155  */
 156 static inline int adi_jtag_ap_write_check(struct adiv5_dap *dap,
 157                 uint8_t reg_addr, uint8_t *outvalue)
 158 {
 159         return adi_jtag_dp_scan(dap, JTAG_DP_APACC, reg_addr, DPAP_WRITE,
 160                         outvalue, NULL, NULL);
 161 }
 162
 163 static int adi_jtag_scan_inout_check_u32(struct adiv5_dap *dap,
 164                 uint8_t instr, uint8_t reg_addr, uint8_t RnW,
 165                 uint32_t outvalue, uint32_t *invalue)
 166 {
 167         int retval;
 168
 169         /* Issue the read or write */
 170         retval = adi_jtag_dp_scan_u32(dap, instr, reg_addr,
 171                         RnW, outvalue, NULL, NULL);
 172         if (retval != ERROR_OK)
 173                 return retval;
 174
 175         /* For reads,  collect posted value; RDBUFF has no other effect.
 176          * Assumes read gets acked with OK/FAULT, and CTRL_STAT says "OK".
 177          */
 178         if ((RnW == DPAP_READ) && (invalue != NULL))
 179                 retval = adi_jtag_dp_scan_u32(dap, JTAG_DP_DPACC,
 180                                 DP_RDBUFF, DPAP_READ, 0, invalue, &dap->ack);
 181         return retval;
 182 }
 183
 184 static int jtagdp_transaction_endcheck(struct adiv5_dap *dap)
 185 {
 186         int retval;
 187         uint32_t ctrlstat;
 188
 189         /* too expensive to call keep_alive() here */
 190
 191 #if 0
 192         /* Danger!!!! BROKEN!!!! */
 193         adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 194                         DP_CTRL_STAT, DPAP_READ, 0, &ctrlstat);
 195         /* Danger!!!! BROKEN!!!! Why will jtag_execute_queue() fail here????
 196         R956 introduced the check on return value here and now Michael Schwingen reports
 197         that this code no longer works....
 198
 199         https://lists.berlios.de/pipermail/openocd-development/2008-September/003107.html
 200         */
 201         if ((retval = jtag_execute_queue()) != ERROR_OK)
 202         {
 203                 LOG_ERROR("BUG: Why does this fail the first time????");
 204         }
 205         /* Why??? second time it works??? */
 206 #endif
 207
 208         /* Post CTRL/STAT read; discard any previous posted read value
 209          * but collect its ACK status.
 210          */
 211         adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 212                         DP_CTRL_STAT, DPAP_READ, 0, &ctrlstat);
 213         if ((retval = jtag_execute_queue()) != ERROR_OK)
 214                 return retval;
 215
 216         dap->ack = dap->ack & 0x7;
 217
 218         /* common code path avoids calling timeval_ms() */
 219         if (dap->ack != JTAG_ACK_OK_FAULT)
 220         {
 221                 long long then = timeval_ms();
 222
 223                 while (dap->ack != JTAG_ACK_OK_FAULT)
 224                 {
 225                         if (dap->ack == JTAG_ACK_WAIT)
 226                         {
 227                                 if ((timeval_ms()-then) > 1000)
 228                                 {
 229                                         /* NOTE:  this would be a good spot
 230                                          * to use JTAG_DP_ABORT.
 231                                          */
 232                                         LOG_WARNING("Timeout (1000ms) waiting "
 233                                                 "for ACK=OK/FAULT "
 234                                                 "in JTAG-DP transaction");
 235                                         return ERROR_JTAG_DEVICE_ERROR;
 236                                 }
 237                         }
 238                         else
 239                         {
 240                                 LOG_WARNING("Invalid ACK %#x "
 241                                                 "in JTAG-DP transaction",
 242                                                 dap->ack);
 243                                 return ERROR_JTAG_DEVICE_ERROR;
 244                         }
 245
 246                         adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 247                                         DP_CTRL_STAT, DPAP_READ, 0, &ctrlstat);
 248                         if ((retval = dap_run(dap)) != ERROR_OK)
 249                                 return retval;
 250                         dap->ack = dap->ack & 0x7;
 251                 }
 252         }
 253
 254         /* REVISIT also STICKYCMP, for pushed comparisons (nyet used) */
 255
 256         /* Check for STICKYERR and STICKYORUN */
 257         if (ctrlstat & (SSTICKYORUN | SSTICKYERR))
 258         {
 259                 LOG_DEBUG("jtag-dp: CTRL/STAT error, 0x%" PRIx32, ctrlstat);
 260                 /* Check power to debug regions */
 261                 if ((ctrlstat & 0xf0000000) != 0xf0000000)
 262                          ahbap_debugport_init(dap);
 263                 else
 264                 {
 265                         uint32_t mem_ap_csw, mem_ap_tar;
 266
 267                         /* Maybe print information about last intended
 268                          * MEM-AP access; but not if autoincrementing.
 269                          * *Real* CSW and TAR values are always shown.
 270                          */
 271                         if (dap->ap_tar_value != (uint32_t) -1)
 272                                 LOG_DEBUG("MEM-AP Cached values: "
 273                                         "ap_bank 0x%" PRIx32
 274                                         ", ap_csw 0x%" PRIx32
 275                                         ", ap_tar 0x%" PRIx32,
 276                                         dap->ap_bank_value,
 277                                         dap->ap_csw_value,
 278                                         dap->ap_tar_value);
 279
 280                         if (ctrlstat & SSTICKYORUN)
 281                                 LOG_ERROR("JTAG-DP OVERRUN - check clock, "
 282                                         "memaccess, or reduce jtag speed");
 283
 284                         if (ctrlstat & SSTICKYERR)
 285                                 LOG_ERROR("JTAG-DP STICKY ERROR");
 286
 287                         /* Clear Sticky Error Bits */
 288                         adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 289                                         DP_CTRL_STAT, DPAP_WRITE,
 290                                         dap->dp_ctrl_stat | SSTICKYORUN
 291                                                 | SSTICKYERR, NULL);
 292                         adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 293                                         DP_CTRL_STAT, DPAP_READ, 0, &ctrlstat);
 294                         if ((retval = dap_run(dap)) != ERROR_OK)
 295                                 return retval;
 296
 297                         LOG_DEBUG("jtag-dp: CTRL/STAT 0x%" PRIx32, ctrlstat);
 298
 299                         retval = dap_queue_ap_read(dap,
 300                                         AP_REG_CSW, &mem_ap_csw);
 301                         if (retval != ERROR_OK)
 302                                 return retval;
 303
 304                         retval = dap_queue_ap_read(dap,
 305                                         AP_REG_TAR, &mem_ap_tar);
 306                         if (retval != ERROR_OK)
 307                                 return retval;
 308
 309                         if ((retval = dap_run(dap)) != ERROR_OK)
 310                                 return retval;
 311                         LOG_ERROR("MEM_AP_CSW 0x%" PRIx32 ", MEM_AP_TAR 0x%"
 312                                         PRIx32, mem_ap_csw, mem_ap_tar);
 313
 314                 }
 315                 if ((retval = dap_run(dap)) != ERROR_OK)
 316                         return retval;
 317                 return ERROR_JTAG_DEVICE_ERROR;
 318         }
 319
 320         return ERROR_OK;
 321 }
 322
 323 /*--------------------------------------------------------------------------*/
 324
 325 static int jtag_idcode_q_read(struct adiv5_dap *dap,
 326                 uint8_t *ack, uint32_t *data)
 327 {
 328         struct arm_jtag *jtag_info = dap->jtag_info;
 329         int retval;
 330         struct scan_field fields[1];
 331
 332         /* This is a standard JTAG operation -- no DAP tweakage */
 333         retval = arm_jtag_set_instr(jtag_info, JTAG_DP_IDCODE, NULL, TAP_IDLE);
 334         if (retval != ERROR_OK)
 335                 return retval;
 336
 337         fields[0].num_bits = 32;
 338         fields[0].out_value = NULL;
 339         fields[0].in_value = (void *) data;
 340
 341         jtag_add_dr_scan(jtag_info->tap, 1, fields, TAP_IDLE);
 342         retval = jtag_get_error();
 343         if (retval != ERROR_OK)
 344                 return retval;
 345
 346         jtag_add_callback(arm_le_to_h_u32,
 347                         (jtag_callback_data_t) data);
 348
 349         return retval;
 350 }
 351
 352 static int jtag_dp_q_read(struct adiv5_dap *dap, unsigned reg,
 353                 uint32_t *data)
 354 {
 355         return adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 356                         reg, DPAP_READ, 0, data);
 357 }
 358
 359 static int jtag_dp_q_write(struct adiv5_dap *dap, unsigned reg,
 360                 uint32_t data)
 361 {
 362         return adi_jtag_scan_inout_check_u32(dap, JTAG_DP_DPACC,
 363                         reg, DPAP_WRITE, data, NULL);
 364 }
 365
 366 /** Select the AP register bank matching bits 7:4 of reg. */
 367 static int jtag_ap_q_bankselect(struct adiv5_dap *dap, unsigned reg)
 368 {
 369         uint32_t select = reg & 0x000000F0;
 370
 371         if (select == dap->ap_bank_value)
 372                 return ERROR_OK;
 373         dap->ap_bank_value = select;
 374
 375         select |= dap->apsel;
 376
 377         return jtag_dp_q_write(dap, DP_SELECT, select);
 378 }
 379
 380 static int jtag_ap_q_read(struct adiv5_dap *dap, unsigned reg,
 381                 uint32_t *data)
 382 {
 383         int retval = jtag_ap_q_bankselect(dap, reg);
 384
 385         if (retval != ERROR_OK)
 386                 return retval;
 387
 388         return adi_jtag_scan_inout_check_u32(dap, JTAG_DP_APACC, reg,
 389                         DPAP_READ, 0, data);
 390 }
 391
 392 static int jtag_ap_q_write(struct adiv5_dap *dap, unsigned reg,
 393                 uint32_t data)
 394 {
 395         uint8_t out_value_buf[4];
 396
 397         int retval = jtag_ap_q_bankselect(dap, reg);
 398         if (retval != ERROR_OK)
 399                 return retval;
 400
 401         buf_set_u32(out_value_buf, 0, 32, data);
 402
 403         return adi_jtag_ap_write_check(dap, reg, out_value_buf);
 404 }
 405
 406 static int jtag_ap_q_abort(struct adiv5_dap *dap, uint8_t *ack)
 407 {
 408         /* for JTAG, this is the only valid ABORT register operation */
 409         return adi_jtag_dp_scan_u32(dap, JTAG_DP_ABORT,
 410                         0, DPAP_WRITE, 1, NULL, ack);
 411 }
 412
 413 static int jtag_dp_run(struct adiv5_dap *dap)
 414 {
 415         return jtagdp_transaction_endcheck(dap);
 416 }
 417
 418 /* FIXME don't export ... just initialize as
 419  * part of DAP setup
 420 */
 421 const struct dap_ops jtag_dp_ops = {
 422         .queue_idcode_read =    jtag_idcode_q_read,
 423         .queue_dp_read =        jtag_dp_q_read,
 424         .queue_dp_write =       jtag_dp_q_write,
 425         .queue_ap_read =        jtag_ap_q_read,
 426         .queue_ap_write =       jtag_ap_q_write,
 427         .queue_ap_abort =       jtag_ap_q_abort,
 428         .run =                  jtag_dp_run,
 429 };
 430
 431
 432 static const uint8_t swd2jtag_bitseq[] = {
 433         /* More than 50 TCK/SWCLK cycles with TMS/SWDIO high,
 434          * putting both JTAG and SWD logic into reset state.
 435          */
 436         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 437         /* Switching equence disables SWD and enables JTAG
 438          * NOTE: bits in the DP's IDCODE can expose the need for
 439          * the old/deprecated sequence (0xae 0xde).
 440          */
 441         0x3c, 0xe7,
 442         /* At least 50 TCK/SWCLK cycles with TMS/SWDIO high,
 443          * putting both JTAG and SWD logic into reset state.
 444          * NOTE:  some docs say "at least 5".
 445          */
 446         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 447 };
 448
 449 /** Put the debug link into JTAG mode, if the target supports it.
 450  * The link's initial mode may be either SWD or JTAG.
 451  *
 452  * @param target Enters JTAG mode (if possible).
 453  *
 454  * Note that targets implemented with SW-DP do not support JTAG, and
 455  * that some targets which could otherwise support it may have been
 456  * configured to disable JTAG signaling
 457  *
 458  * @return ERROR_OK or else a fault code.
 459  */
 460 int dap_to_jtag(struct target *target)
 461 {
 462         int retval;
 463
 464         LOG_DEBUG("Enter JTAG mode");
 465
 466         /* REVISIT it's nasty to need to make calls to a "jtag"
 467          * subsystem if the link isn't in JTAG mode...
 468          */
 469
 470         retval = jtag_add_tms_seq(8 * sizeof(swd2jtag_bitseq),
 471                         swd2jtag_bitseq, TAP_RESET);
 472         if (retval == ERROR_OK)
 473                 retval = jtag_execute_queue();
 474
 475         /* REVISIT set up the DAP's ops vector for JTAG mode. */
 476
 477         return retval;
 478 }