drivers/ddr/fsl/lc_common_dimm_params.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2008-2016 Freescale Semiconductor, Inc.
   4  * Copyright 2017-2021 NXP Semiconductor
   5  */
   6
   7 #include <common.h>
   8 #include <fsl_ddr_sdram.h>
   9 #include <log.h>
  10 #include <asm/bitops.h>
  11
  12 #include <fsl_ddr.h>
  13
  14 #if defined(CONFIG_SYS_FSL_DDR3) || defined(CONFIG_SYS_FSL_DDR4)
  15 static unsigned int
  16 compute_cas_latency(const unsigned int ctrl_num,
  17                     const dimm_params_t *dimm_params,
  18                     common_timing_params_t *outpdimm,
  19                     unsigned int number_of_dimms)
  20 {
  21         unsigned int i;
  22         unsigned int common_caslat;
  23         unsigned int caslat_actual;
  24         unsigned int retry = 16;
  25         unsigned int tmp = ~0;
  26         unsigned int mclk_ps = get_memory_clk_period_ps(ctrl_num);
  27 #ifdef CONFIG_SYS_FSL_DDR3
  28         const unsigned int taamax = 20000;
  29 #else
  30         const unsigned int taamax = 18000;
  31 #endif
  32
  33         /* compute the common CAS latency supported between slots */
  34         for (i = 0; i < number_of_dimms; i++) {
  35                 if (dimm_params[i].n_ranks)
  36                         tmp &= dimm_params[i].caslat_x;
  37         }
  38         common_caslat = tmp;
  39
  40         if (!mclk_ps) {
  41                 printf("DDR clock (MCLK cycle was 0 ps), So setting it to slowest DIMM(s) (tCKmin %u ps).\n",
  42                        outpdimm->tckmin_x_ps);
  43                 mclk_ps = outpdimm->tckmin_x_ps;
  44         }
  45
  46         /* validate if the memory clk is in the range of dimms */
  47         if (mclk_ps < outpdimm->tckmin_x_ps) {
  48                 printf("DDR clock (MCLK cycle %u ps) is faster than "
  49                         "the slowest DIMM(s) (tCKmin %u ps) can support.\n",
  50                         mclk_ps, outpdimm->tckmin_x_ps);
  51         }
  52 #ifdef CONFIG_SYS_FSL_DDR4
  53         if (mclk_ps > outpdimm->tckmax_ps) {
  54                 printf("DDR clock (MCLK cycle %u ps) is slower than DIMM(s) (tCKmax %u ps) can support.\n",
  55                        mclk_ps, outpdimm->tckmax_ps);
  56         }
  57 #endif
  58         /* determine the acutal cas latency */
  59         caslat_actual = (outpdimm->taamin_ps + mclk_ps - 1) / mclk_ps;
  60         /* check if the dimms support the CAS latency */
  61         while (!(common_caslat & (1 << caslat_actual)) && retry > 0) {
  62                 caslat_actual++;
  63                 retry--;
  64         }
  65         /* once the caculation of caslat_actual is completed
  66          * we must verify that this CAS latency value does not
  67          * exceed tAAmax, which is 20 ns for all DDR3 speed grades,
  68          * 18ns for all DDR4 speed grades.
  69          */
  70         if (caslat_actual * mclk_ps > taamax) {
  71                 printf("The chosen cas latency %d is too large\n",
  72                        caslat_actual);
  73         }
  74         outpdimm->lowest_common_spd_caslat = caslat_actual;
  75         debug("lowest_common_spd_caslat is 0x%x\n", caslat_actual);
  76
  77         return 0;
  78 }
  79 #else   /* for DDR1 and DDR2 */
  80 static unsigned int
  81 compute_cas_latency(const unsigned int ctrl_num,
  82                     const dimm_params_t *dimm_params,
  83                     common_timing_params_t *outpdimm,
  84                     unsigned int number_of_dimms)
  85 {
  86         int i;
  87         const unsigned int mclk_ps = get_memory_clk_period_ps(ctrl_num);
  88         unsigned int lowest_good_caslat;
  89         unsigned int not_ok;
  90         unsigned int temp1, temp2;
  91
  92         debug("using mclk_ps = %u\n", mclk_ps);
  93         if (mclk_ps > outpdimm->tckmax_ps) {
  94                 printf("Warning: DDR clock (%u ps) is slower than DIMM(s) (tCKmax %u ps)\n",
  95                        mclk_ps, outpdimm->tckmax_ps);
  96         }
  97
  98         /*
  99          * Compute a CAS latency suitable for all DIMMs
 100          *
 101          * Strategy for SPD-defined latencies: compute only
 102          * CAS latency defined by all DIMMs.
 103          */
 104
 105         /*
 106          * Step 1: find CAS latency common to all DIMMs using bitwise
 107          * operation.
 108          */
 109         temp1 = 0xFF;
 110         for (i = 0; i < number_of_dimms; i++) {
 111                 if (dimm_params[i].n_ranks) {
 112                         temp2 = 0;
 113                         temp2 |= 1 << dimm_params[i].caslat_x;
 114                         temp2 |= 1 << dimm_params[i].caslat_x_minus_1;
 115                         temp2 |= 1 << dimm_params[i].caslat_x_minus_2;
 116                         /*
 117                          * If there was no entry for X-2 (X-1) in
 118                          * the SPD, then caslat_x_minus_2
 119                          * (caslat_x_minus_1) contains either 255 or
 120                          * 0xFFFFFFFF because that's what the glorious
 121                          * __ilog2 function returns for an input of 0.
 122                          * On 32-bit PowerPC, left shift counts with bit
 123                          * 26 set (that the value of 255 or 0xFFFFFFFF
 124                          * will have), cause the destination register to
 125                          * be 0.  That is why this works.
 126                          */
 127                         temp1 &= temp2;
 128                 }
 129         }
 130
 131         /*
 132          * Step 2: check each common CAS latency against tCK of each
 133          * DIMM's SPD.
 134          */
 135         lowest_good_caslat = 0;
 136         temp2 = 0;
 137         while (temp1) {
 138                 not_ok = 0;
 139                 temp2 =  __ilog2(temp1);
 140                 debug("checking common caslat = %u\n", temp2);
 141
 142                 /* Check if this CAS latency will work on all DIMMs at tCK. */
 143                 for (i = 0; i < number_of_dimms; i++) {
 144                         if (!dimm_params[i].n_ranks)
 145                                 continue;
 146
 147                         if (dimm_params[i].caslat_x == temp2) {
 148                                 if (mclk_ps >= dimm_params[i].tckmin_x_ps) {
 149                                         debug("CL = %u ok on DIMM %u at tCK=%u ps with tCKmin_X_ps of %u\n",
 150                                               temp2, i, mclk_ps,
 151                                               dimm_params[i].tckmin_x_ps);
 152                                         continue;
 153                                 } else {
 154                                         not_ok++;
 155                                 }
 156                         }
 157
 158                         if (dimm_params[i].caslat_x_minus_1 == temp2) {
 159                                 unsigned int tckmin_x_minus_1_ps
 160                                         = dimm_params[i].tckmin_x_minus_1_ps;
 161                                 if (mclk_ps >= tckmin_x_minus_1_ps) {
 162                                         debug("CL = %u ok on DIMM %u at tCK=%u ps with tckmin_x_minus_1_ps of %u\n",
 163                                               temp2, i, mclk_ps,
 164                                               tckmin_x_minus_1_ps);
 165                                         continue;
 166                                 } else {
 167                                         not_ok++;
 168                                 }
 169                         }
 170
 171                         if (dimm_params[i].caslat_x_minus_2 == temp2) {
 172                                 unsigned int tckmin_x_minus_2_ps
 173                                         = dimm_params[i].tckmin_x_minus_2_ps;
 174                                 if (mclk_ps >= tckmin_x_minus_2_ps) {
 175                                         debug("CL = %u ok on DIMM %u at tCK=%u ps with tckmin_x_minus_2_ps of %u\n",
 176                                               temp2, i, mclk_ps,
 177                                               tckmin_x_minus_2_ps);
 178                                         continue;
 179                                 } else {
 180                                         not_ok++;
 181                                 }
 182                         }
 183                 }
 184
 185                 if (!not_ok)
 186                         lowest_good_caslat = temp2;
 187
 188                 temp1 &= ~(1 << temp2);
 189         }
 190
 191         debug("lowest common SPD-defined CAS latency = %u\n",
 192               lowest_good_caslat);
 193         outpdimm->lowest_common_spd_caslat = lowest_good_caslat;
 194
 195
 196         /*
 197          * Compute a common 'de-rated' CAS latency.
 198          *
 199          * The strategy here is to find the *highest* dereated cas latency
 200          * with the assumption that all of the DIMMs will support a dereated
 201          * CAS latency higher than or equal to their lowest dereated value.
 202          */
 203         temp1 = 0;
 204         for (i = 0; i < number_of_dimms; i++)
 205                 temp1 = max(temp1, dimm_params[i].caslat_lowest_derated);
 206
 207         outpdimm->highest_common_derated_caslat = temp1;
 208         debug("highest common dereated CAS latency = %u\n", temp1);
 209
 210         return 0;
 211 }
 212 #endif
 213
 214 /*
 215  * compute_lowest_common_dimm_parameters()
 216  *
 217  * Determine the worst-case DIMM timing parameters from the set of DIMMs
 218  * whose parameters have been computed into the array pointed to
 219  * by dimm_params.
 220  */
 221 unsigned int
 222 compute_lowest_common_dimm_parameters(const unsigned int ctrl_num,
 223                                       const dimm_params_t *dimm_params,
 224                                       common_timing_params_t *outpdimm,
 225                                       const unsigned int number_of_dimms)
 226 {
 227         unsigned int i, j;
 228
 229         unsigned int tckmin_x_ps = 0;
 230         unsigned int tckmax_ps = 0xFFFFFFFF;
 231         unsigned int trcd_ps = 0;
 232         unsigned int trp_ps = 0;
 233         unsigned int tras_ps = 0;
 234 #if defined(CONFIG_SYS_FSL_DDR3) || defined(CONFIG_SYS_FSL_DDR4)
 235         unsigned int taamin_ps = 0;
 236 #endif
 237 #ifdef CONFIG_SYS_FSL_DDR4
 238         unsigned int twr_ps = 15000;
 239         unsigned int trfc1_ps = 0;
 240         unsigned int trfc2_ps = 0;
 241         unsigned int trfc4_ps = 0;
 242         unsigned int trrds_ps = 0;
 243         unsigned int trrdl_ps = 0;
 244         unsigned int tccdl_ps = 0;
 245         unsigned int trfc_slr_ps = 0;
 246 #else
 247         unsigned int twr_ps = 0;
 248         unsigned int twtr_ps = 0;
 249         unsigned int trfc_ps = 0;
 250         unsigned int trrd_ps = 0;
 251         unsigned int trtp_ps = 0;
 252 #endif
 253         unsigned int trc_ps = 0;
 254         unsigned int refresh_rate_ps = 0;
 255         unsigned int extended_op_srt = 1;
 256 #if defined(CONFIG_SYS_FSL_DDR1) || defined(CONFIG_SYS_FSL_DDR2)
 257         unsigned int tis_ps = 0;
 258         unsigned int tih_ps = 0;
 259         unsigned int tds_ps = 0;
 260         unsigned int tdh_ps = 0;
 261         unsigned int tdqsq_max_ps = 0;
 262         unsigned int tqhs_ps = 0;
 263 #endif
 264         unsigned int temp1, temp2;
 265         unsigned int additive_latency = 0;
 266
 267         temp1 = 0;
 268         for (i = 0; i < number_of_dimms; i++) {
 269                 /*
 270                  * If there are no ranks on this DIMM,
 271                  * it probably doesn't exist, so skip it.
 272                  */
 273                 if (dimm_params[i].n_ranks == 0) {
 274                         temp1++;
 275                         continue;
 276                 }
 277                 if (dimm_params[i].n_ranks == 4 && i != 0) {
 278                         printf("Found Quad-rank DIMM in wrong bank, ignored."
 279                                 " Software may not run as expected.\n");
 280                         temp1++;
 281                         continue;
 282                 }
 283
 284                 /*
 285                  * check if quad-rank DIMM is plugged if
 286                  * CONFIG_CHIP_SELECT_QUAD_CAPABLE is not defined
 287                  * Only the board with proper design is capable
 288                  */
 289 #ifndef CONFIG_FSL_DDR_FIRST_SLOT_QUAD_CAPABLE
 290                 if (dimm_params[i].n_ranks == 4 && \
 291                   CONFIG_CHIP_SELECTS_PER_CTRL/CONFIG_DIMM_SLOTS_PER_CTLR < 4) {
 292                         printf("Found Quad-rank DIMM, not able to support.");
 293                         temp1++;
 294                         continue;
 295                 }
 296 #endif
 297                 /*
 298                  * Find minimum tckmax_ps to find fastest slow speed,
 299                  * i.e., this is the slowest the whole system can go.
 300                  */
 301                 tckmax_ps = min(tckmax_ps,
 302                                 (unsigned int)dimm_params[i].tckmax_ps);
 303 #if defined(CONFIG_SYS_FSL_DDR3) || defined(CONFIG_SYS_FSL_DDR4)
 304                 taamin_ps = max(taamin_ps,
 305                                 (unsigned int)dimm_params[i].taa_ps);
 306 #endif
 307                 tckmin_x_ps = max(tckmin_x_ps,
 308                                   (unsigned int)dimm_params[i].tckmin_x_ps);
 309                 trcd_ps = max(trcd_ps, (unsigned int)dimm_params[i].trcd_ps);
 310                 trp_ps = max(trp_ps, (unsigned int)dimm_params[i].trp_ps);
 311                 tras_ps = max(tras_ps, (unsigned int)dimm_params[i].tras_ps);
 312 #ifdef CONFIG_SYS_FSL_DDR4
 313                 trfc1_ps = max(trfc1_ps,
 314                                (unsigned int)dimm_params[i].trfc1_ps);
 315                 trfc2_ps = max(trfc2_ps,
 316                                (unsigned int)dimm_params[i].trfc2_ps);
 317                 trfc4_ps = max(trfc4_ps,
 318                                (unsigned int)dimm_params[i].trfc4_ps);
 319                 trrds_ps = max(trrds_ps,
 320                                (unsigned int)dimm_params[i].trrds_ps);
 321                 trrdl_ps = max(trrdl_ps,
 322                                (unsigned int)dimm_params[i].trrdl_ps);
 323                 tccdl_ps = max(tccdl_ps,
 324                                (unsigned int)dimm_params[i].tccdl_ps);
 325                 trfc_slr_ps = max(trfc_slr_ps,
 326                                   (unsigned int)dimm_params[i].trfc_slr_ps);
 327 #else
 328                 twr_ps = max(twr_ps, (unsigned int)dimm_params[i].twr_ps);
 329                 twtr_ps = max(twtr_ps, (unsigned int)dimm_params[i].twtr_ps);
 330                 trfc_ps = max(trfc_ps, (unsigned int)dimm_params[i].trfc_ps);
 331                 trrd_ps = max(trrd_ps, (unsigned int)dimm_params[i].trrd_ps);
 332                 trtp_ps = max(trtp_ps, (unsigned int)dimm_params[i].trtp_ps);
 333 #endif
 334                 trc_ps = max(trc_ps, (unsigned int)dimm_params[i].trc_ps);
 335 #if defined(CONFIG_SYS_FSL_DDR1) || defined(CONFIG_SYS_FSL_DDR2)
 336                 tis_ps = max(tis_ps, (unsigned int)dimm_params[i].tis_ps);
 337                 tih_ps = max(tih_ps, (unsigned int)dimm_params[i].tih_ps);
 338                 tds_ps = max(tds_ps, (unsigned int)dimm_params[i].tds_ps);
 339                 tdh_ps = max(tdh_ps, (unsigned int)dimm_params[i].tdh_ps);
 340                 tqhs_ps = max(tqhs_ps, (unsigned int)dimm_params[i].tqhs_ps);
 341                 /*
 342                  * Find maximum tdqsq_max_ps to find slowest.
 343                  *
 344                  * FIXME: is finding the slowest value the correct
 345                  * strategy for this parameter?
 346                  */
 347                 tdqsq_max_ps = max(tdqsq_max_ps,
 348                                    (unsigned int)dimm_params[i].tdqsq_max_ps);
 349 #endif
 350                 refresh_rate_ps = max(refresh_rate_ps,
 351                                       (unsigned int)dimm_params[i].refresh_rate_ps);
 352                 /* extended_op_srt is either 0 or 1, 0 having priority */
 353                 extended_op_srt = min(extended_op_srt,
 354                                       (unsigned int)dimm_params[i].extended_op_srt);
 355         }
 356
 357         outpdimm->ndimms_present = number_of_dimms - temp1;
 358
 359         if (temp1 == number_of_dimms) {
 360                 debug("no dimms this memory controller\n");
 361                 return 0;
 362         }
 363
 364         outpdimm->tckmin_x_ps = tckmin_x_ps;
 365         outpdimm->tckmax_ps = tckmax_ps;
 366 #if defined(CONFIG_SYS_FSL_DDR3) || defined(CONFIG_SYS_FSL_DDR4)
 367         outpdimm->taamin_ps = taamin_ps;
 368 #endif
 369         outpdimm->trcd_ps = trcd_ps;
 370         outpdimm->trp_ps = trp_ps;
 371         outpdimm->tras_ps = tras_ps;
 372 #ifdef CONFIG_SYS_FSL_DDR4
 373         outpdimm->trfc1_ps = trfc1_ps;
 374         outpdimm->trfc2_ps = trfc2_ps;
 375         outpdimm->trfc4_ps = trfc4_ps;
 376         outpdimm->trrds_ps = trrds_ps;
 377         outpdimm->trrdl_ps = trrdl_ps;
 378         outpdimm->tccdl_ps = tccdl_ps;
 379         outpdimm->trfc_slr_ps = trfc_slr_ps;
 380 #else
 381         outpdimm->twtr_ps = twtr_ps;
 382         outpdimm->trfc_ps = trfc_ps;
 383         outpdimm->trrd_ps = trrd_ps;
 384         outpdimm->trtp_ps = trtp_ps;
 385 #endif
 386         outpdimm->twr_ps = twr_ps;
 387         outpdimm->trc_ps = trc_ps;
 388         outpdimm->refresh_rate_ps = refresh_rate_ps;
 389         outpdimm->extended_op_srt = extended_op_srt;
 390 #if defined(CONFIG_SYS_FSL_DDR1) || defined(CONFIG_SYS_FSL_DDR2)
 391         outpdimm->tis_ps = tis_ps;
 392         outpdimm->tih_ps = tih_ps;
 393         outpdimm->tds_ps = tds_ps;
 394         outpdimm->tdh_ps = tdh_ps;
 395         outpdimm->tdqsq_max_ps = tdqsq_max_ps;
 396         outpdimm->tqhs_ps = tqhs_ps;
 397 #endif
 398
 399         /* Determine common burst length for all DIMMs. */
 400         temp1 = 0xff;
 401         for (i = 0; i < number_of_dimms; i++) {
 402                 if (dimm_params[i].n_ranks) {
 403                         temp1 &= dimm_params[i].burst_lengths_bitmask;
 404                 }
 405         }
 406         outpdimm->all_dimms_burst_lengths_bitmask = temp1;
 407
 408         /* Determine if all DIMMs registered buffered. */
 409         temp1 = temp2 = 0;
 410         for (i = 0; i < number_of_dimms; i++) {
 411                 if (dimm_params[i].n_ranks) {
 412                         if (dimm_params[i].registered_dimm) {
 413                                 temp1 = 1;
 414 #ifndef CONFIG_SPL_BUILD
 415                                 printf("Detected RDIMM %s\n",
 416                                         dimm_params[i].mpart);
 417 #endif
 418                         } else {
 419                                 temp2 = 1;
 420 #ifndef CONFIG_SPL_BUILD
 421                                 printf("Detected UDIMM %s\n",
 422                                         dimm_params[i].mpart);
 423 #endif
 424                         }
 425                 }
 426         }
 427
 428         outpdimm->all_dimms_registered = 0;
 429         outpdimm->all_dimms_unbuffered = 0;
 430         if (temp1 && !temp2) {
 431                 outpdimm->all_dimms_registered = 1;
 432         } else if (!temp1 && temp2) {
 433                 outpdimm->all_dimms_unbuffered = 1;
 434         } else {
 435                 printf("ERROR:  Mix of registered buffered and unbuffered "
 436                                 "DIMMs detected!\n");
 437         }
 438
 439         temp1 = 0;
 440         if (outpdimm->all_dimms_registered)
 441                 for (j = 0; j < 16; j++) {
 442                         outpdimm->rcw[j] = dimm_params[0].rcw[j];
 443                         for (i = 1; i < number_of_dimms; i++) {
 444                                 if (!dimm_params[i].n_ranks)
 445                                         continue;
 446                                 if (dimm_params[i].rcw[j] != dimm_params[0].rcw[j]) {
 447                                         temp1 = 1;
 448                                         break;
 449                                 }
 450                         }
 451                 }
 452
 453         if (temp1 != 0)
 454                 printf("ERROR: Mix different RDIMM detected!\n");
 455
 456         /* calculate cas latency for all DDR types */
 457         if (compute_cas_latency(ctrl_num, dimm_params,
 458                                 outpdimm, number_of_dimms))
 459                 return 1;
 460
 461         /* Determine if all DIMMs ECC capable. */
 462         temp1 = 1;
 463         for (i = 0; i < number_of_dimms; i++) {
 464                 if (dimm_params[i].n_ranks &&
 465                         !(dimm_params[i].edc_config & EDC_ECC)) {
 466                         temp1 = 0;
 467                         break;
 468                 }
 469         }
 470         if (temp1) {
 471                 debug("all DIMMs ECC capable\n");
 472         } else {
 473                 debug("Warning: not all DIMMs ECC capable, cant enable ECC\n");
 474         }
 475         outpdimm->all_dimms_ecc_capable = temp1;
 476
 477         /*
 478          * Compute additive latency.
 479          *
 480          * For DDR1, additive latency should be 0.
 481          *
 482          * For DDR2, with ODT enabled, use "a value" less than ACTTORW,
 483          *      which comes from Trcd, and also note that:
 484          *          add_lat + caslat must be >= 4
 485          *
 486          * For DDR3, we use the AL=0
 487          *
 488          * When to use additive latency for DDR2:
 489          *
 490          * I. Because you are using CL=3 and need to do ODT on writes and
 491          *    want functionality.
 492          *    1. Are you going to use ODT? (Does your board not have
 493          *      additional termination circuitry for DQ, DQS, DQS_,
 494          *      DM, RDQS, RDQS_ for x4/x8 configs?)
 495          *    2. If so, is your lowest supported CL going to be 3?
 496          *    3. If so, then you must set AL=1 because
 497          *
 498          *       WL >= 3 for ODT on writes
 499          *       RL = AL + CL
 500          *       WL = RL - 1
 501          *       ->
 502          *       WL = AL + CL - 1
 503          *       AL + CL - 1 >= 3
 504          *       AL + CL >= 4
 505          *  QED
 506          *
 507          *  RL >= 3 for ODT on reads
 508          *  RL = AL + CL
 509          *
 510          *  Since CL aren't usually less than 2, AL=0 is a minimum,
 511          *  so the WL-derived AL should be the  -- FIXME?
 512          *
 513          * II. Because you are using auto-precharge globally and want to
 514          *     use additive latency (posted CAS) to get more bandwidth.
 515          *     1. Are you going to use auto-precharge mode globally?
 516          *
 517          *        Use addtivie latency and compute AL to be 1 cycle less than
 518          *        tRCD, i.e. the READ or WRITE command is in the cycle
 519          *        immediately following the ACTIVATE command..
 520          *
 521          * III. Because you feel like it or want to do some sort of
 522          *      degraded-performance experiment.
 523          *     1.  Do you just want to use additive latency because you feel
 524          *         like it?
 525          *
 526          * Validation:  AL is less than tRCD, and within the other
 527          * read-to-precharge constraints.
 528          */
 529
 530         additive_latency = 0;
 531
 532 #if defined(CONFIG_SYS_FSL_DDR2)
 533         if ((outpdimm->lowest_common_spd_caslat < 4) &&
 534             (picos_to_mclk(ctrl_num, trcd_ps) >
 535              outpdimm->lowest_common_spd_caslat)) {
 536                 additive_latency = picos_to_mclk(ctrl_num, trcd_ps) -
 537                                    outpdimm->lowest_common_spd_caslat;
 538                 if (mclk_to_picos(ctrl_num, additive_latency) > trcd_ps) {
 539                         additive_latency = picos_to_mclk(ctrl_num, trcd_ps);
 540                         debug("setting additive_latency to %u because it was "
 541                                 " greater than tRCD_ps\n", additive_latency);
 542                 }
 543         }
 544 #endif
 545
 546         /*
 547          * Validate additive latency
 548          *
 549          * AL <= tRCD(min)
 550          */
 551         if (mclk_to_picos(ctrl_num, additive_latency) > trcd_ps) {
 552                 printf("Error: invalid additive latency exceeds tRCD(min).\n");
 553                 return 1;
 554         }
 555
 556         /*
 557          * RL = CL + AL;  RL >= 3 for ODT_RD_CFG to be enabled
 558          * WL = RL - 1;  WL >= 3 for ODT_WL_CFG to be enabled
 559          * ADD_LAT (the register) must be set to a value less
 560          * than ACTTORW if WL = 1, then AL must be set to 1
 561          * RD_TO_PRE (the register) must be set to a minimum
 562          * tRTP + AL if AL is nonzero
 563          */
 564
 565         /*
 566          * Additive latency will be applied only if the memctl option to
 567          * use it.
 568          */
 569         outpdimm->additive_latency = additive_latency;
 570
 571         debug("tCKmin_ps = %u\n", outpdimm->tckmin_x_ps);
 572         debug("trcd_ps   = %u\n", outpdimm->trcd_ps);
 573         debug("trp_ps    = %u\n", outpdimm->trp_ps);
 574         debug("tras_ps   = %u\n", outpdimm->tras_ps);
 575 #ifdef CONFIG_SYS_FSL_DDR4
 576         debug("trfc1_ps = %u\n", trfc1_ps);
 577         debug("trfc2_ps = %u\n", trfc2_ps);
 578         debug("trfc4_ps = %u\n", trfc4_ps);
 579         debug("trrds_ps = %u\n", trrds_ps);
 580         debug("trrdl_ps = %u\n", trrdl_ps);
 581         debug("tccdl_ps = %u\n", tccdl_ps);
 582         debug("trfc_slr_ps = %u\n", trfc_slr_ps);
 583 #else
 584         debug("twtr_ps   = %u\n", outpdimm->twtr_ps);
 585         debug("trfc_ps   = %u\n", outpdimm->trfc_ps);
 586         debug("trrd_ps   = %u\n", outpdimm->trrd_ps);
 587 #endif
 588         debug("twr_ps    = %u\n", outpdimm->twr_ps);
 589         debug("trc_ps    = %u\n", outpdimm->trc_ps);
 590
 591         return 0;
 592 }