drivers/opp/of.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Generic OPP OF helpers
   4  *
   5  * Copyright (C) 2009-2010 Texas Instruments Incorporated.
   6  *      Nishanth Menon
   7  *      Romit Dasgupta
   8  *      Kevin Hilman
   9  */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/cpu.h>
  14 #include <linux/errno.h>
  15 #include <linux/device.h>
  16 #include <linux/of_device.h>
  17 #include <linux/pm_domain.h>
  18 #include <linux/slab.h>
  19 #include <linux/export.h>
  20 #include <linux/energy_model.h>
  21
  22 #include "opp.h"
  23
  24 /*
  25  * Returns opp descriptor node for a device node, caller must
  26  * do of_node_put().
  27  */
  28 static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np,
  29                                                      int index)
  30 {
  31         /* "operating-points-v2" can be an array for power domain providers */
  32         return of_parse_phandle(np, "operating-points-v2", index);
  33 }
  34
  35 /* Returns opp descriptor node for a device, caller must do of_node_put() */
  36 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
  37 {
  38         return _opp_of_get_opp_desc_node(dev->of_node, 0);
  39 }
  40 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
  41
  42 struct opp_table *_managed_opp(struct device *dev, int index)
  43 {
  44         struct opp_table *opp_table, *managed_table = NULL;
  45         struct device_node *np;
  46
  47         np = _opp_of_get_opp_desc_node(dev->of_node, index);
  48         if (!np)
  49                 return NULL;
  50
  51         list_for_each_entry(opp_table, &opp_tables, node) {
  52                 if (opp_table->np == np) {
  53                         /*
  54                          * Multiple devices can point to the same OPP table and
  55                          * so will have same node-pointer, np.
  56                          *
  57                          * But the OPPs will be considered as shared only if the
  58                          * OPP table contains a "opp-shared" property.
  59                          */
  60                         if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
  61                                 _get_opp_table_kref(opp_table);
  62                                 managed_table = opp_table;
  63                         }
  64
  65                         break;
  66                 }
  67         }
  68
  69         of_node_put(np);
  70
  71         return managed_table;
  72 }
  73
  74 /* The caller must call dev_pm_opp_put() after the OPP is used */
  75 static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table,
  76                                           struct device_node *opp_np)
  77 {
  78         struct dev_pm_opp *opp;
  79
  80         mutex_lock(&opp_table->lock);
  81
  82         list_for_each_entry(opp, &opp_table->opp_list, node) {
  83                 if (opp->np == opp_np) {
  84                         dev_pm_opp_get(opp);
  85                         mutex_unlock(&opp_table->lock);
  86                         return opp;
  87                 }
  88         }
  89
  90         mutex_unlock(&opp_table->lock);
  91
  92         return NULL;
  93 }
  94
  95 static struct device_node *of_parse_required_opp(struct device_node *np,
  96                                                  int index)
  97 {
  98         return of_parse_phandle(np, "required-opps", index);
  99 }
 100
 101 /* The caller must call dev_pm_opp_put_opp_table() after the table is used */
 102 static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
 103 {
 104         struct opp_table *opp_table;
 105         struct device_node *opp_table_np;
 106
 107         opp_table_np = of_get_parent(opp_np);
 108         if (!opp_table_np)
 109                 goto err;
 110
 111         /* It is safe to put the node now as all we need now is its address */
 112         of_node_put(opp_table_np);
 113
 114         mutex_lock(&opp_table_lock);
 115         list_for_each_entry(opp_table, &opp_tables, node) {
 116                 if (opp_table_np == opp_table->np) {
 117                         _get_opp_table_kref(opp_table);
 118                         mutex_unlock(&opp_table_lock);
 119                         return opp_table;
 120                 }
 121         }
 122         mutex_unlock(&opp_table_lock);
 123
 124 err:
 125         return ERR_PTR(-ENODEV);
 126 }
 127
 128 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
 129 static void _opp_table_free_required_tables(struct opp_table *opp_table)
 130 {
 131         struct opp_table **required_opp_tables = opp_table->required_opp_tables;
 132         int i;
 133
 134         if (!required_opp_tables)
 135                 return;
 136
 137         for (i = 0; i < opp_table->required_opp_count; i++) {
 138                 if (IS_ERR_OR_NULL(required_opp_tables[i]))
 139                         continue;
 140
 141                 dev_pm_opp_put_opp_table(required_opp_tables[i]);
 142         }
 143
 144         kfree(required_opp_tables);
 145
 146         opp_table->required_opp_count = 0;
 147         opp_table->required_opp_tables = NULL;
 148         list_del(&opp_table->lazy);
 149 }
 150
 151 /*
 152  * Populate all devices and opp tables which are part of "required-opps" list.
 153  * Checking only the first OPP node should be enough.
 154  */
 155 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
 156                                              struct device *dev,
 157                                              struct device_node *opp_np)
 158 {
 159         struct opp_table **required_opp_tables;
 160         struct device_node *required_np, *np;
 161         bool lazy = false;
 162         int count, i;
 163
 164         /* Traversing the first OPP node is all we need */
 165         np = of_get_next_available_child(opp_np, NULL);
 166         if (!np) {
 167                 dev_warn(dev, "Empty OPP table\n");
 168
 169                 return;
 170         }
 171
 172         count = of_count_phandle_with_args(np, "required-opps", NULL);
 173         if (count <= 0)
 174                 goto put_np;
 175
 176         required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
 177                                       GFP_KERNEL);
 178         if (!required_opp_tables)
 179                 goto put_np;
 180
 181         opp_table->required_opp_tables = required_opp_tables;
 182         opp_table->required_opp_count = count;
 183
 184         for (i = 0; i < count; i++) {
 185                 required_np = of_parse_required_opp(np, i);
 186                 if (!required_np)
 187                         goto free_required_tables;
 188
 189                 required_opp_tables[i] = _find_table_of_opp_np(required_np);
 190                 of_node_put(required_np);
 191
 192                 if (IS_ERR(required_opp_tables[i]))
 193                         lazy = true;
 194         }
 195
 196         /* Let's do the linking later on */
 197         if (lazy)
 198                 list_add(&opp_table->lazy, &lazy_opp_tables);
 199
 200         goto put_np;
 201
 202 free_required_tables:
 203         _opp_table_free_required_tables(opp_table);
 204 put_np:
 205         of_node_put(np);
 206 }
 207
 208 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
 209                         int index)
 210 {
 211         struct device_node *np, *opp_np;
 212         u32 val;
 213
 214         /*
 215          * Only required for backward compatibility with v1 bindings, but isn't
 216          * harmful for other cases. And so we do it unconditionally.
 217          */
 218         np = of_node_get(dev->of_node);
 219         if (!np)
 220                 return;
 221
 222         if (!of_property_read_u32(np, "clock-latency", &val))
 223                 opp_table->clock_latency_ns_max = val;
 224         of_property_read_u32(np, "voltage-tolerance",
 225                              &opp_table->voltage_tolerance_v1);
 226
 227         if (of_find_property(np, "#power-domain-cells", NULL))
 228                 opp_table->is_genpd = true;
 229
 230         /* Get OPP table node */
 231         opp_np = _opp_of_get_opp_desc_node(np, index);
 232         of_node_put(np);
 233
 234         if (!opp_np)
 235                 return;
 236
 237         if (of_property_read_bool(opp_np, "opp-shared"))
 238                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
 239         else
 240                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
 241
 242         opp_table->np = opp_np;
 243
 244         _opp_table_alloc_required_tables(opp_table, dev, opp_np);
 245 }
 246
 247 void _of_clear_opp_table(struct opp_table *opp_table)
 248 {
 249         _opp_table_free_required_tables(opp_table);
 250         of_node_put(opp_table->np);
 251 }
 252
 253 /*
 254  * Release all resources previously acquired with a call to
 255  * _of_opp_alloc_required_opps().
 256  */
 257 static void _of_opp_free_required_opps(struct opp_table *opp_table,
 258                                        struct dev_pm_opp *opp)
 259 {
 260         struct dev_pm_opp **required_opps = opp->required_opps;
 261         int i;
 262
 263         if (!required_opps)
 264                 return;
 265
 266         for (i = 0; i < opp_table->required_opp_count; i++) {
 267                 if (!required_opps[i])
 268                         continue;
 269
 270                 /* Put the reference back */
 271                 dev_pm_opp_put(required_opps[i]);
 272         }
 273
 274         opp->required_opps = NULL;
 275         kfree(required_opps);
 276 }
 277
 278 void _of_clear_opp(struct opp_table *opp_table, struct dev_pm_opp *opp)
 279 {
 280         _of_opp_free_required_opps(opp_table, opp);
 281         of_node_put(opp->np);
 282 }
 283
 284 /* Populate all required OPPs which are part of "required-opps" list */
 285 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
 286                                        struct dev_pm_opp *opp)
 287 {
 288         struct dev_pm_opp **required_opps;
 289         struct opp_table *required_table;
 290         struct device_node *np;
 291         int i, ret, count = opp_table->required_opp_count;
 292
 293         if (!count)
 294                 return 0;
 295
 296         required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
 297         if (!required_opps)
 298                 return -ENOMEM;
 299
 300         opp->required_opps = required_opps;
 301
 302         for (i = 0; i < count; i++) {
 303                 required_table = opp_table->required_opp_tables[i];
 304
 305                 /* Required table not added yet, we will link later */
 306                 if (IS_ERR_OR_NULL(required_table))
 307                         continue;
 308
 309                 np = of_parse_required_opp(opp->np, i);
 310                 if (unlikely(!np)) {
 311                         ret = -ENODEV;
 312                         goto free_required_opps;
 313                 }
 314
 315                 required_opps[i] = _find_opp_of_np(required_table, np);
 316                 of_node_put(np);
 317
 318                 if (!required_opps[i]) {
 319                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
 320                                __func__, opp->np, i);
 321                         ret = -ENODEV;
 322                         goto free_required_opps;
 323                 }
 324         }
 325
 326         return 0;
 327
 328 free_required_opps:
 329         _of_opp_free_required_opps(opp_table, opp);
 330
 331         return ret;
 332 }
 333
 334 /* Link required OPPs for an individual OPP */
 335 static int lazy_link_required_opps(struct opp_table *opp_table,
 336                                    struct opp_table *new_table, int index)
 337 {
 338         struct device_node *required_np;
 339         struct dev_pm_opp *opp;
 340
 341         list_for_each_entry(opp, &opp_table->opp_list, node) {
 342                 required_np = of_parse_required_opp(opp->np, index);
 343                 if (unlikely(!required_np))
 344                         return -ENODEV;
 345
 346                 opp->required_opps[index] = _find_opp_of_np(new_table, required_np);
 347                 of_node_put(required_np);
 348
 349                 if (!opp->required_opps[index]) {
 350                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
 351                                __func__, opp->np, index);
 352                         return -ENODEV;
 353                 }
 354         }
 355
 356         return 0;
 357 }
 358
 359 /* Link required OPPs for all OPPs of the newly added OPP table */
 360 static void lazy_link_required_opp_table(struct opp_table *new_table)
 361 {
 362         struct opp_table *opp_table, *temp, **required_opp_tables;
 363         struct device_node *required_np, *opp_np, *required_table_np;
 364         struct dev_pm_opp *opp;
 365         int i, ret;
 366
 367         mutex_lock(&opp_table_lock);
 368
 369         list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
 370                 bool lazy = false;
 371
 372                 /* opp_np can't be invalid here */
 373                 opp_np = of_get_next_available_child(opp_table->np, NULL);
 374
 375                 for (i = 0; i < opp_table->required_opp_count; i++) {
 376                         required_opp_tables = opp_table->required_opp_tables;
 377
 378                         /* Required opp-table is already parsed */
 379                         if (!IS_ERR(required_opp_tables[i]))
 380                                 continue;
 381
 382                         /* required_np can't be invalid here */
 383                         required_np = of_parse_required_opp(opp_np, i);
 384                         required_table_np = of_get_parent(required_np);
 385
 386                         of_node_put(required_table_np);
 387                         of_node_put(required_np);
 388
 389                         /*
 390                          * Newly added table isn't the required opp-table for
 391                          * opp_table.
 392                          */
 393                         if (required_table_np != new_table->np) {
 394                                 lazy = true;
 395                                 continue;
 396                         }
 397
 398                         required_opp_tables[i] = new_table;
 399                         _get_opp_table_kref(new_table);
 400
 401                         /* Link OPPs now */
 402                         ret = lazy_link_required_opps(opp_table, new_table, i);
 403                         if (ret) {
 404                                 /* The OPPs will be marked unusable */
 405                                 lazy = false;
 406                                 break;
 407                         }
 408                 }
 409
 410                 of_node_put(opp_np);
 411
 412                 /* All required opp-tables found, remove from lazy list */
 413                 if (!lazy) {
 414                         list_del_init(&opp_table->lazy);
 415
 416                         list_for_each_entry(opp, &opp_table->opp_list, node)
 417                                 _required_opps_available(opp, opp_table->required_opp_count);
 418                 }
 419         }
 420
 421         mutex_unlock(&opp_table_lock);
 422 }
 423
 424 static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
 425 {
 426         struct device_node *np, *opp_np;
 427         struct property *prop;
 428
 429         if (!opp_table) {
 430                 np = of_node_get(dev->of_node);
 431                 if (!np)
 432                         return -ENODEV;
 433
 434                 opp_np = _opp_of_get_opp_desc_node(np, 0);
 435                 of_node_put(np);
 436         } else {
 437                 opp_np = of_node_get(opp_table->np);
 438         }
 439
 440         /* Lets not fail in case we are parsing opp-v1 bindings */
 441         if (!opp_np)
 442                 return 0;
 443
 444         /* Checking only first OPP is sufficient */
 445         np = of_get_next_available_child(opp_np, NULL);
 446         of_node_put(opp_np);
 447         if (!np) {
 448                 dev_err(dev, "OPP table empty\n");
 449                 return -EINVAL;
 450         }
 451
 452         prop = of_find_property(np, "opp-peak-kBps", NULL);
 453         of_node_put(np);
 454
 455         if (!prop || !prop->length)
 456                 return 0;
 457
 458         return 1;
 459 }
 460
 461 int dev_pm_opp_of_find_icc_paths(struct device *dev,
 462                                  struct opp_table *opp_table)
 463 {
 464         struct device_node *np;
 465         int ret, i, count, num_paths;
 466         struct icc_path **paths;
 467
 468         ret = _bandwidth_supported(dev, opp_table);
 469         if (ret == -EINVAL)
 470                 return 0; /* Empty OPP table is a valid corner-case, let's not fail */
 471         else if (ret <= 0)
 472                 return ret;
 473
 474         ret = 0;
 475
 476         np = of_node_get(dev->of_node);
 477         if (!np)
 478                 return 0;
 479
 480         count = of_count_phandle_with_args(np, "interconnects",
 481                                            "#interconnect-cells");
 482         of_node_put(np);
 483         if (count < 0)
 484                 return 0;
 485
 486         /* two phandles when #interconnect-cells = <1> */
 487         if (count % 2) {
 488                 dev_err(dev, "%s: Invalid interconnects values\n", __func__);
 489                 return -EINVAL;
 490         }
 491
 492         num_paths = count / 2;
 493         paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
 494         if (!paths)
 495                 return -ENOMEM;
 496
 497         for (i = 0; i < num_paths; i++) {
 498                 paths[i] = of_icc_get_by_index(dev, i);
 499                 if (IS_ERR(paths[i])) {
 500                         ret = PTR_ERR(paths[i]);
 501                         if (ret != -EPROBE_DEFER) {
 502                                 dev_err(dev, "%s: Unable to get path%d: %d\n",
 503                                         __func__, i, ret);
 504                         }
 505                         goto err;
 506                 }
 507         }
 508
 509         if (opp_table) {
 510                 opp_table->paths = paths;
 511                 opp_table->path_count = num_paths;
 512                 return 0;
 513         }
 514
 515 err:
 516         while (i--)
 517                 icc_put(paths[i]);
 518
 519         kfree(paths);
 520
 521         return ret;
 522 }
 523 EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);
 524
 525 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
 526                               struct device_node *np)
 527 {
 528         unsigned int levels = opp_table->supported_hw_count;
 529         int count, versions, ret, i, j;
 530         u32 val;
 531
 532         if (!opp_table->supported_hw) {
 533                 /*
 534                  * In the case that no supported_hw has been set by the
 535                  * platform but there is an opp-supported-hw value set for
 536                  * an OPP then the OPP should not be enabled as there is
 537                  * no way to see if the hardware supports it.
 538                  */
 539                 if (of_find_property(np, "opp-supported-hw", NULL))
 540                         return false;
 541                 else
 542                         return true;
 543         }
 544
 545         count = of_property_count_u32_elems(np, "opp-supported-hw");
 546         if (count <= 0 || count % levels) {
 547                 dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
 548                         __func__, count);
 549                 return false;
 550         }
 551
 552         versions = count / levels;
 553
 554         /* All levels in at least one of the versions should match */
 555         for (i = 0; i < versions; i++) {
 556                 bool supported = true;
 557
 558                 for (j = 0; j < levels; j++) {
 559                         ret = of_property_read_u32_index(np, "opp-supported-hw",
 560                                                          i * levels + j, &val);
 561                         if (ret) {
 562                                 dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
 563                                          __func__, i * levels + j, ret);
 564                                 return false;
 565                         }
 566
 567                         /* Check if the level is supported */
 568                         if (!(val & opp_table->supported_hw[j])) {
 569                                 supported = false;
 570                                 break;
 571                         }
 572                 }
 573
 574                 if (supported)
 575                         return true;
 576         }
 577
 578         return false;
 579 }
 580
 581 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 582                               struct opp_table *opp_table)
 583 {
 584         u32 *microvolt, *microamp = NULL, *microwatt = NULL;
 585         int supplies = opp_table->regulator_count;
 586         int vcount, icount, pcount, ret, i, j;
 587         struct property *prop = NULL;
 588         char name[NAME_MAX];
 589
 590         /* Search for "opp-microvolt-<name>" */
 591         if (opp_table->prop_name) {
 592                 snprintf(name, sizeof(name), "opp-microvolt-%s",
 593                          opp_table->prop_name);
 594                 prop = of_find_property(opp->np, name, NULL);
 595         }
 596
 597         if (!prop) {
 598                 /* Search for "opp-microvolt" */
 599                 sprintf(name, "opp-microvolt");
 600                 prop = of_find_property(opp->np, name, NULL);
 601
 602                 /* Missing property isn't a problem, but an invalid entry is */
 603                 if (!prop) {
 604                         if (unlikely(supplies == -1)) {
 605                                 /* Initialize regulator_count */
 606                                 opp_table->regulator_count = 0;
 607                                 return 0;
 608                         }
 609
 610                         if (!supplies)
 611                                 return 0;
 612
 613                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
 614                                 __func__);
 615                         return -EINVAL;
 616                 }
 617         }
 618
 619         if (unlikely(supplies == -1)) {
 620                 /* Initialize regulator_count */
 621                 supplies = opp_table->regulator_count = 1;
 622         } else if (unlikely(!supplies)) {
 623                 dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
 624                 return -EINVAL;
 625         }
 626
 627         vcount = of_property_count_u32_elems(opp->np, name);
 628         if (vcount < 0) {
 629                 dev_err(dev, "%s: Invalid %s property (%d)\n",
 630                         __func__, name, vcount);
 631                 return vcount;
 632         }
 633
 634         /* There can be one or three elements per supply */
 635         if (vcount != supplies && vcount != supplies * 3) {
 636                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 637                         __func__, name, vcount, supplies);
 638                 return -EINVAL;
 639         }
 640
 641         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
 642         if (!microvolt)
 643                 return -ENOMEM;
 644
 645         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
 646         if (ret) {
 647                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 648                 ret = -EINVAL;
 649                 goto free_microvolt;
 650         }
 651
 652         /* Search for "opp-microamp-<name>" */
 653         prop = NULL;
 654         if (opp_table->prop_name) {
 655                 snprintf(name, sizeof(name), "opp-microamp-%s",
 656                          opp_table->prop_name);
 657                 prop = of_find_property(opp->np, name, NULL);
 658         }
 659
 660         if (!prop) {
 661                 /* Search for "opp-microamp" */
 662                 sprintf(name, "opp-microamp");
 663                 prop = of_find_property(opp->np, name, NULL);
 664         }
 665
 666         if (prop) {
 667                 icount = of_property_count_u32_elems(opp->np, name);
 668                 if (icount < 0) {
 669                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 670                                 name, icount);
 671                         ret = icount;
 672                         goto free_microvolt;
 673                 }
 674
 675                 if (icount != supplies) {
 676                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 677                                 __func__, name, icount, supplies);
 678                         ret = -EINVAL;
 679                         goto free_microvolt;
 680                 }
 681
 682                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
 683                 if (!microamp) {
 684                         ret = -EINVAL;
 685                         goto free_microvolt;
 686                 }
 687
 688                 ret = of_property_read_u32_array(opp->np, name, microamp,
 689                                                  icount);
 690                 if (ret) {
 691                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 692                                 name, ret);
 693                         ret = -EINVAL;
 694                         goto free_microamp;
 695                 }
 696         }
 697
 698         /* Search for "opp-microwatt" */
 699         sprintf(name, "opp-microwatt");
 700         prop = of_find_property(opp->np, name, NULL);
 701
 702         if (prop) {
 703                 pcount = of_property_count_u32_elems(opp->np, name);
 704                 if (pcount < 0) {
 705                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 706                                 name, pcount);
 707                         ret = pcount;
 708                         goto free_microamp;
 709                 }
 710
 711                 if (pcount != supplies) {
 712                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 713                                 __func__, name, pcount, supplies);
 714                         ret = -EINVAL;
 715                         goto free_microamp;
 716                 }
 717
 718                 microwatt = kmalloc_array(pcount, sizeof(*microwatt),
 719                                           GFP_KERNEL);
 720                 if (!microwatt) {
 721                         ret = -EINVAL;
 722                         goto free_microamp;
 723                 }
 724
 725                 ret = of_property_read_u32_array(opp->np, name, microwatt,
 726                                                  pcount);
 727                 if (ret) {
 728                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 729                                 name, ret);
 730                         ret = -EINVAL;
 731                         goto free_microwatt;
 732                 }
 733         }
 734
 735         for (i = 0, j = 0; i < supplies; i++) {
 736                 opp->supplies[i].u_volt = microvolt[j++];
 737
 738                 if (vcount == supplies) {
 739                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
 740                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
 741                 } else {
 742                         opp->supplies[i].u_volt_min = microvolt[j++];
 743                         opp->supplies[i].u_volt_max = microvolt[j++];
 744                 }
 745
 746                 if (microamp)
 747                         opp->supplies[i].u_amp = microamp[i];
 748
 749                 if (microwatt)
 750                         opp->supplies[i].u_watt = microwatt[i];
 751         }
 752
 753 free_microwatt:
 754         kfree(microwatt);
 755 free_microamp:
 756         kfree(microamp);
 757 free_microvolt:
 758         kfree(microvolt);
 759
 760         return ret;
 761 }
 762
 763 /**
 764  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 765  *                                entries
 766  * @dev:        device pointer used to lookup OPP table.
 767  *
 768  * Free OPPs created using static entries present in DT.
 769  */
 770 void dev_pm_opp_of_remove_table(struct device *dev)
 771 {
 772         dev_pm_opp_remove_table(dev);
 773 }
 774 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 775
 776 static int _read_rate(struct dev_pm_opp *new_opp, struct opp_table *opp_table,
 777                       struct device_node *np)
 778 {
 779         struct property *prop;
 780         int i, count, ret;
 781         u64 *rates;
 782
 783         prop = of_find_property(np, "opp-hz", NULL);
 784         if (!prop)
 785                 return -ENODEV;
 786
 787         count = prop->length / sizeof(u64);
 788         if (opp_table->clk_count != count) {
 789                 pr_err("%s: Count mismatch between opp-hz and clk_count (%d %d)\n",
 790                        __func__, count, opp_table->clk_count);
 791                 return -EINVAL;
 792         }
 793
 794         rates = kmalloc_array(count, sizeof(*rates), GFP_KERNEL);
 795         if (!rates)
 796                 return -ENOMEM;
 797
 798         ret = of_property_read_u64_array(np, "opp-hz", rates, count);
 799         if (ret) {
 800                 pr_err("%s: Error parsing opp-hz: %d\n", __func__, ret);
 801         } else {
 802                 /*
 803                  * Rate is defined as an unsigned long in clk API, and so
 804                  * casting explicitly to its type. Must be fixed once rate is 64
 805                  * bit guaranteed in clk API.
 806                  */
 807                 for (i = 0; i < count; i++) {
 808                         new_opp->rates[i] = (unsigned long)rates[i];
 809
 810                         /* This will happen for frequencies > 4.29 GHz */
 811                         WARN_ON(new_opp->rates[i] != rates[i]);
 812                 }
 813         }
 814
 815         kfree(rates);
 816
 817         return ret;
 818 }
 819
 820 static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *opp_table,
 821                     struct device_node *np, bool peak)
 822 {
 823         const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
 824         struct property *prop;
 825         int i, count, ret;
 826         u32 *bw;
 827
 828         prop = of_find_property(np, name, NULL);
 829         if (!prop)
 830                 return -ENODEV;
 831
 832         count = prop->length / sizeof(u32);
 833         if (opp_table->path_count != count) {
 834                 pr_err("%s: Mismatch between %s and paths (%d %d)\n",
 835                                 __func__, name, count, opp_table->path_count);
 836                 return -EINVAL;
 837         }
 838
 839         bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
 840         if (!bw)
 841                 return -ENOMEM;
 842
 843         ret = of_property_read_u32_array(np, name, bw, count);
 844         if (ret) {
 845                 pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
 846                 goto out;
 847         }
 848
 849         for (i = 0; i < count; i++) {
 850                 if (peak)
 851                         new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
 852                 else
 853                         new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
 854         }
 855
 856 out:
 857         kfree(bw);
 858         return ret;
 859 }
 860
 861 static int _read_opp_key(struct dev_pm_opp *new_opp,
 862                          struct opp_table *opp_table, struct device_node *np)
 863 {
 864         bool found = false;
 865         int ret;
 866
 867         ret = _read_rate(new_opp, opp_table, np);
 868         if (!ret)
 869                 found = true;
 870         else if (ret != -ENODEV)
 871                 return ret;
 872
 873         /*
 874          * Bandwidth consists of peak and average (optional) values:
 875          * opp-peak-kBps = <path1_value path2_value>;
 876          * opp-avg-kBps = <path1_value path2_value>;
 877          */
 878         ret = _read_bw(new_opp, opp_table, np, true);
 879         if (!ret) {
 880                 found = true;
 881                 ret = _read_bw(new_opp, opp_table, np, false);
 882         }
 883
 884         /* The properties were found but we failed to parse them */
 885         if (ret && ret != -ENODEV)
 886                 return ret;
 887
 888         if (!of_property_read_u32(np, "opp-level", &new_opp->level))
 889                 found = true;
 890
 891         if (found)
 892                 return 0;
 893
 894         return ret;
 895 }
 896
 897 /**
 898  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 899  * @opp_table:  OPP table
 900  * @dev:        device for which we do this operation
 901  * @np:         device node
 902  *
 903  * This function adds an opp definition to the opp table and returns status. The
 904  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 905  * removed by dev_pm_opp_remove.
 906  *
 907  * Return:
 908  * Valid OPP pointer:
 909  *              On success
 910  * NULL:
 911  *              Duplicate OPPs (both freq and volt are same) and opp->available
 912  *              OR if the OPP is not supported by hardware.
 913  * ERR_PTR(-EEXIST):
 914  *              Freq are same and volt are different OR
 915  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 916  * ERR_PTR(-ENOMEM):
 917  *              Memory allocation failure
 918  * ERR_PTR(-EINVAL):
 919  *              Failed parsing the OPP node
 920  */
 921 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 922                 struct device *dev, struct device_node *np)
 923 {
 924         struct dev_pm_opp *new_opp;
 925         u32 val;
 926         int ret;
 927
 928         new_opp = _opp_allocate(opp_table);
 929         if (!new_opp)
 930                 return ERR_PTR(-ENOMEM);
 931
 932         ret = _read_opp_key(new_opp, opp_table, np);
 933         if (ret < 0) {
 934                 dev_err(dev, "%s: opp key field not found\n", __func__);
 935                 goto free_opp;
 936         }
 937
 938         /* Check if the OPP supports hardware's hierarchy of versions or not */
 939         if (!_opp_is_supported(dev, opp_table, np)) {
 940                 dev_dbg(dev, "OPP not supported by hardware: %s\n",
 941                         of_node_full_name(np));
 942                 goto free_opp;
 943         }
 944
 945         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 946
 947         new_opp->np = of_node_get(np);
 948         new_opp->dynamic = false;
 949         new_opp->available = true;
 950
 951         ret = _of_opp_alloc_required_opps(opp_table, new_opp);
 952         if (ret)
 953                 goto free_opp;
 954
 955         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 956                 new_opp->clock_latency_ns = val;
 957
 958         ret = opp_parse_supplies(new_opp, dev, opp_table);
 959         if (ret)
 960                 goto free_required_opps;
 961
 962         if (opp_table->is_genpd)
 963                 new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
 964
 965         ret = _opp_add(dev, new_opp, opp_table);
 966         if (ret) {
 967                 /* Don't return error for duplicate OPPs */
 968                 if (ret == -EBUSY)
 969                         ret = 0;
 970                 goto free_required_opps;
 971         }
 972
 973         /* OPP to select on device suspend */
 974         if (of_property_read_bool(np, "opp-suspend")) {
 975                 if (opp_table->suspend_opp) {
 976                         /* Pick the OPP with higher rate/bw/level as suspend OPP */
 977                         if (_opp_compare_key(opp_table, new_opp, opp_table->suspend_opp) == 1) {
 978                                 opp_table->suspend_opp->suspend = false;
 979                                 new_opp->suspend = true;
 980                                 opp_table->suspend_opp = new_opp;
 981                         }
 982                 } else {
 983                         new_opp->suspend = true;
 984                         opp_table->suspend_opp = new_opp;
 985                 }
 986         }
 987
 988         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 989                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 990
 991         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu level:%u\n",
 992                  __func__, new_opp->turbo, new_opp->rates[0],
 993                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 994                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns,
 995                  new_opp->level);
 996
 997         /*
 998          * Notify the changes in the availability of the operable
 999          * frequency/voltage list.
1000          */
1001         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
1002         return new_opp;
1003
1004 free_required_opps:
1005         _of_opp_free_required_opps(opp_table, new_opp);
1006 free_opp:
1007         _opp_free(new_opp);
1008
1009         return ret ? ERR_PTR(ret) : NULL;
1010 }
1011
1012 /* Initializes OPP tables based on new bindings */
1013 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
1014 {
1015         struct device_node *np;
1016         int ret, count = 0;
1017         struct dev_pm_opp *opp;
1018
1019         /* OPP table is already initialized for the device */
1020         mutex_lock(&opp_table->lock);
1021         if (opp_table->parsed_static_opps) {
1022                 opp_table->parsed_static_opps++;
1023                 mutex_unlock(&opp_table->lock);
1024                 return 0;
1025         }
1026
1027         opp_table->parsed_static_opps = 1;
1028         mutex_unlock(&opp_table->lock);
1029
1030         /* We have opp-table node now, iterate over it and add OPPs */
1031         for_each_available_child_of_node(opp_table->np, np) {
1032                 opp = _opp_add_static_v2(opp_table, dev, np);
1033                 if (IS_ERR(opp)) {
1034                         ret = PTR_ERR(opp);
1035                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
1036                                 ret);
1037                         of_node_put(np);
1038                         goto remove_static_opp;
1039                 } else if (opp) {
1040                         count++;
1041                 }
1042         }
1043
1044         /* There should be one or more OPPs defined */
1045         if (!count) {
1046                 dev_err(dev, "%s: no supported OPPs", __func__);
1047                 ret = -ENOENT;
1048                 goto remove_static_opp;
1049         }
1050
1051         list_for_each_entry(opp, &opp_table->opp_list, node) {
1052                 /* Any non-zero performance state would enable the feature */
1053                 if (opp->pstate) {
1054                         opp_table->genpd_performance_state = true;
1055                         break;
1056                 }
1057         }
1058
1059         lazy_link_required_opp_table(opp_table);
1060
1061         return 0;
1062
1063 remove_static_opp:
1064         _opp_remove_all_static(opp_table);
1065
1066         return ret;
1067 }
1068
1069 /* Initializes OPP tables based on old-deprecated bindings */
1070 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
1071 {
1072         const struct property *prop;
1073         const __be32 *val;
1074         int nr, ret = 0;
1075
1076         mutex_lock(&opp_table->lock);
1077         if (opp_table->parsed_static_opps) {
1078                 opp_table->parsed_static_opps++;
1079                 mutex_unlock(&opp_table->lock);
1080                 return 0;
1081         }
1082
1083         opp_table->parsed_static_opps = 1;
1084         mutex_unlock(&opp_table->lock);
1085
1086         prop = of_find_property(dev->of_node, "operating-points", NULL);
1087         if (!prop) {
1088                 ret = -ENODEV;
1089                 goto remove_static_opp;
1090         }
1091         if (!prop->value) {
1092                 ret = -ENODATA;
1093                 goto remove_static_opp;
1094         }
1095
1096         /*
1097          * Each OPP is a set of tuples consisting of frequency and
1098          * voltage like <freq-kHz vol-uV>.
1099          */
1100         nr = prop->length / sizeof(u32);
1101         if (nr % 2) {
1102                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
1103                 ret = -EINVAL;
1104                 goto remove_static_opp;
1105         }
1106
1107         val = prop->value;
1108         while (nr) {
1109                 unsigned long freq = be32_to_cpup(val++) * 1000;
1110                 unsigned long volt = be32_to_cpup(val++);
1111
1112                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
1113                 if (ret) {
1114                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
1115                                 __func__, freq, ret);
1116                         goto remove_static_opp;
1117                 }
1118                 nr -= 2;
1119         }
1120
1121         return 0;
1122
1123 remove_static_opp:
1124         _opp_remove_all_static(opp_table);
1125
1126         return ret;
1127 }
1128
1129 static int _of_add_table_indexed(struct device *dev, int index)
1130 {
1131         struct opp_table *opp_table;
1132         int ret, count;
1133
1134         if (index) {
1135                 /*
1136                  * If only one phandle is present, then the same OPP table
1137                  * applies for all index requests.
1138                  */
1139                 count = of_count_phandle_with_args(dev->of_node,
1140                                                    "operating-points-v2", NULL);
1141                 if (count == 1)
1142                         index = 0;
1143         }
1144
1145         opp_table = _add_opp_table_indexed(dev, index, true);
1146         if (IS_ERR(opp_table))
1147                 return PTR_ERR(opp_table);
1148
1149         /*
1150          * OPPs have two version of bindings now. Also try the old (v1)
1151          * bindings for backward compatibility with older dtbs.
1152          */
1153         if (opp_table->np)
1154                 ret = _of_add_opp_table_v2(dev, opp_table);
1155         else
1156                 ret = _of_add_opp_table_v1(dev, opp_table);
1157
1158         if (ret)
1159                 dev_pm_opp_put_opp_table(opp_table);
1160
1161         return ret;
1162 }
1163
1164 static void devm_pm_opp_of_table_release(void *data)
1165 {
1166         dev_pm_opp_of_remove_table(data);
1167 }
1168
1169 static int _devm_of_add_table_indexed(struct device *dev, int index)
1170 {
1171         int ret;
1172
1173         ret = _of_add_table_indexed(dev, index);
1174         if (ret)
1175                 return ret;
1176
1177         return devm_add_action_or_reset(dev, devm_pm_opp_of_table_release, dev);
1178 }
1179
1180 /**
1181  * devm_pm_opp_of_add_table() - Initialize opp table from device tree
1182  * @dev:        device pointer used to lookup OPP table.
1183  *
1184  * Register the initial OPP table with the OPP library for given device.
1185  *
1186  * The opp_table structure will be freed after the device is destroyed.
1187  *
1188  * Return:
1189  * 0            On success OR
1190  *              Duplicate OPPs (both freq and volt are same) and opp->available
1191  * -EEXIST      Freq are same and volt are different OR
1192  *              Duplicate OPPs (both freq and volt are same) and !opp->available
1193  * -ENOMEM      Memory allocation failure
1194  * -ENODEV      when 'operating-points' property is not found or is invalid data
1195  *              in device node.
1196  * -ENODATA     when empty 'operating-points' property is found
1197  * -EINVAL      when invalid entries are found in opp-v2 table
1198  */
1199 int devm_pm_opp_of_add_table(struct device *dev)
1200 {
1201         return _devm_of_add_table_indexed(dev, 0);
1202 }
1203 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table);
1204
1205 /**
1206  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
1207  * @dev:        device pointer used to lookup OPP table.
1208  *
1209  * Register the initial OPP table with the OPP library for given device.
1210  *
1211  * Return:
1212  * 0            On success OR
1213  *              Duplicate OPPs (both freq and volt are same) and opp->available
1214  * -EEXIST      Freq are same and volt are different OR
1215  *              Duplicate OPPs (both freq and volt are same) and !opp->available
1216  * -ENOMEM      Memory allocation failure
1217  * -ENODEV      when 'operating-points' property is not found or is invalid data
1218  *              in device node.
1219  * -ENODATA     when empty 'operating-points' property is found
1220  * -EINVAL      when invalid entries are found in opp-v2 table
1221  */
1222 int dev_pm_opp_of_add_table(struct device *dev)
1223 {
1224         return _of_add_table_indexed(dev, 0);
1225 }
1226 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
1227
1228 /**
1229  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1230  * @dev:        device pointer used to lookup OPP table.
1231  * @index:      Index number.
1232  *
1233  * Register the initial OPP table with the OPP library for given device only
1234  * using the "operating-points-v2" property.
1235  *
1236  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1237  */
1238 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
1239 {
1240         return _of_add_table_indexed(dev, index);
1241 }
1242 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
1243
1244 /**
1245  * devm_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1246  * @dev:        device pointer used to lookup OPP table.
1247  * @index:      Index number.
1248  *
1249  * This is a resource-managed variant of dev_pm_opp_of_add_table_indexed().
1250  */
1251 int devm_pm_opp_of_add_table_indexed(struct device *dev, int index)
1252 {
1253         return _devm_of_add_table_indexed(dev, index);
1254 }
1255 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table_indexed);
1256
1257 /* CPU device specific helpers */
1258
1259 /**
1260  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
1261  * @cpumask:    cpumask for which OPP table needs to be removed
1262  *
1263  * This removes the OPP tables for CPUs present in the @cpumask.
1264  * This should be used only to remove static entries created from DT.
1265  */
1266 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
1267 {
1268         _dev_pm_opp_cpumask_remove_table(cpumask, -1);
1269 }
1270 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
1271
1272 /**
1273  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
1274  * @cpumask:    cpumask for which OPP table needs to be added.
1275  *
1276  * This adds the OPP tables for CPUs present in the @cpumask.
1277  */
1278 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
1279 {
1280         struct device *cpu_dev;
1281         int cpu, ret;
1282
1283         if (WARN_ON(cpumask_empty(cpumask)))
1284                 return -ENODEV;
1285
1286         for_each_cpu(cpu, cpumask) {
1287                 cpu_dev = get_cpu_device(cpu);
1288                 if (!cpu_dev) {
1289                         pr_err("%s: failed to get cpu%d device\n", __func__,
1290                                cpu);
1291                         ret = -ENODEV;
1292                         goto remove_table;
1293                 }
1294
1295                 ret = dev_pm_opp_of_add_table(cpu_dev);
1296                 if (ret) {
1297                         /*
1298                          * OPP may get registered dynamically, don't print error
1299                          * message here.
1300                          */
1301                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
1302                                  __func__, cpu, ret);
1303
1304                         goto remove_table;
1305                 }
1306         }
1307
1308         return 0;
1309
1310 remove_table:
1311         /* Free all other OPPs */
1312         _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
1313
1314         return ret;
1315 }
1316 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
1317
1318 /*
1319  * Works only for OPP v2 bindings.
1320  *
1321  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
1322  */
1323 /**
1324  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
1325  *                                    @cpu_dev using operating-points-v2
1326  *                                    bindings.
1327  *
1328  * @cpu_dev:    CPU device for which we do this operation
1329  * @cpumask:    cpumask to update with information of sharing CPUs
1330  *
1331  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
1332  *
1333  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
1334  */
1335 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
1336                                    struct cpumask *cpumask)
1337 {
1338         struct device_node *np, *tmp_np, *cpu_np;
1339         int cpu, ret = 0;
1340
1341         /* Get OPP descriptor node */
1342         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
1343         if (!np) {
1344                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
1345                 return -ENOENT;
1346         }
1347
1348         cpumask_set_cpu(cpu_dev->id, cpumask);
1349
1350         /* OPPs are shared ? */
1351         if (!of_property_read_bool(np, "opp-shared"))
1352                 goto put_cpu_node;
1353
1354         for_each_possible_cpu(cpu) {
1355                 if (cpu == cpu_dev->id)
1356                         continue;
1357
1358                 cpu_np = of_cpu_device_node_get(cpu);
1359                 if (!cpu_np) {
1360                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
1361                                 __func__, cpu);
1362                         ret = -ENOENT;
1363                         goto put_cpu_node;
1364                 }
1365
1366                 /* Get OPP descriptor node */
1367                 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
1368                 of_node_put(cpu_np);
1369                 if (!tmp_np) {
1370                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
1371                         ret = -ENOENT;
1372                         goto put_cpu_node;
1373                 }
1374
1375                 /* CPUs are sharing opp node */
1376                 if (np == tmp_np)
1377                         cpumask_set_cpu(cpu, cpumask);
1378
1379                 of_node_put(tmp_np);
1380         }
1381
1382 put_cpu_node:
1383         of_node_put(np);
1384         return ret;
1385 }
1386 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
1387
1388 /**
1389  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
1390  * @np: Node that contains the "required-opps" property.
1391  * @index: Index of the phandle to parse.
1392  *
1393  * Returns the performance state of the OPP pointed out by the "required-opps"
1394  * property at @index in @np.
1395  *
1396  * Return: Zero or positive performance state on success, otherwise negative
1397  * value on errors.
1398  */
1399 int of_get_required_opp_performance_state(struct device_node *np, int index)
1400 {
1401         struct dev_pm_opp *opp;
1402         struct device_node *required_np;
1403         struct opp_table *opp_table;
1404         int pstate = -EINVAL;
1405
1406         required_np = of_parse_required_opp(np, index);
1407         if (!required_np)
1408                 return -ENODEV;
1409
1410         opp_table = _find_table_of_opp_np(required_np);
1411         if (IS_ERR(opp_table)) {
1412                 pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
1413                        __func__, np, PTR_ERR(opp_table));
1414                 goto put_required_np;
1415         }
1416
1417         opp = _find_opp_of_np(opp_table, required_np);
1418         if (opp) {
1419                 pstate = opp->pstate;
1420                 dev_pm_opp_put(opp);
1421         }
1422
1423         dev_pm_opp_put_opp_table(opp_table);
1424
1425 put_required_np:
1426         of_node_put(required_np);
1427
1428         return pstate;
1429 }
1430 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1431
1432 /**
1433  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1434  * @opp:        opp for which DT node has to be returned for
1435  *
1436  * Return: DT node corresponding to the opp, else 0 on success.
1437  *
1438  * The caller needs to put the node with of_node_put() after using it.
1439  */
1440 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1441 {
1442         if (IS_ERR_OR_NULL(opp)) {
1443                 pr_err("%s: Invalid parameters\n", __func__);
1444                 return NULL;
1445         }
1446
1447         return of_node_get(opp->np);
1448 }
1449 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1450
1451 /*
1452  * Callback function provided to the Energy Model framework upon registration.
1453  * It provides the power used by @dev at @kHz if it is the frequency of an
1454  * existing OPP, or at the frequency of the first OPP above @kHz otherwise
1455  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1456  * frequency and @uW to the associated power.
1457  *
1458  * Returns 0 on success or a proper -EINVAL value in case of error.
1459  */
1460 static int __maybe_unused
1461 _get_dt_power(struct device *dev, unsigned long *uW, unsigned long *kHz)
1462 {
1463         struct dev_pm_opp *opp;
1464         unsigned long opp_freq, opp_power;
1465
1466         /* Find the right frequency and related OPP */
1467         opp_freq = *kHz * 1000;
1468         opp = dev_pm_opp_find_freq_ceil(dev, &opp_freq);
1469         if (IS_ERR(opp))
1470                 return -EINVAL;
1471
1472         opp_power = dev_pm_opp_get_power(opp);
1473         dev_pm_opp_put(opp);
1474         if (!opp_power)
1475                 return -EINVAL;
1476
1477         *kHz = opp_freq / 1000;
1478         *uW = opp_power;
1479
1480         return 0;
1481 }
1482
1483 /*
1484  * Callback function provided to the Energy Model framework upon registration.
1485  * This computes the power estimated by @dev at @kHz if it is the frequency
1486  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1487  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1488  * frequency and @uW to the associated power. The power is estimated as
1489  * P = C * V^2 * f with C being the device's capacitance and V and f
1490  * respectively the voltage and frequency of the OPP.
1491  *
1492  * Returns -EINVAL if the power calculation failed because of missing
1493  * parameters, 0 otherwise.
1494  */
1495 static int __maybe_unused _get_power(struct device *dev, unsigned long *uW,
1496                                      unsigned long *kHz)
1497 {
1498         struct dev_pm_opp *opp;
1499         struct device_node *np;
1500         unsigned long mV, Hz;
1501         u32 cap;
1502         u64 tmp;
1503         int ret;
1504
1505         np = of_node_get(dev->of_node);
1506         if (!np)
1507                 return -EINVAL;
1508
1509         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1510         of_node_put(np);
1511         if (ret)
1512                 return -EINVAL;
1513
1514         Hz = *kHz * 1000;
1515         opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
1516         if (IS_ERR(opp))
1517                 return -EINVAL;
1518
1519         mV = dev_pm_opp_get_voltage(opp) / 1000;
1520         dev_pm_opp_put(opp);
1521         if (!mV)
1522                 return -EINVAL;
1523
1524         tmp = (u64)cap * mV * mV * (Hz / 1000000);
1525         /* Provide power in micro-Watts */
1526         do_div(tmp, 1000000);
1527
1528         *uW = (unsigned long)tmp;
1529         *kHz = Hz / 1000;
1530
1531         return 0;
1532 }
1533
1534 static bool _of_has_opp_microwatt_property(struct device *dev)
1535 {
1536         unsigned long power, freq = 0;
1537         struct dev_pm_opp *opp;
1538
1539         /* Check if at least one OPP has needed property */
1540         opp = dev_pm_opp_find_freq_ceil(dev, &freq);
1541         if (IS_ERR(opp))
1542                 return false;
1543
1544         power = dev_pm_opp_get_power(opp);
1545         dev_pm_opp_put(opp);
1546         if (!power)
1547                 return false;
1548
1549         return true;
1550 }
1551
1552 /**
1553  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1554  * @dev         : Device for which an Energy Model has to be registered
1555  * @cpus        : CPUs for which an Energy Model has to be registered. For
1556  *              other type of devices it should be set to NULL.
1557  *
1558  * This checks whether the "dynamic-power-coefficient" devicetree property has
1559  * been specified, and tries to register an Energy Model with it if it has.
1560  * Having this property means the voltages are known for OPPs and the EM
1561  * might be calculated.
1562  */
1563 int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
1564 {
1565         struct em_data_callback em_cb;
1566         struct device_node *np;
1567         int ret, nr_opp;
1568         u32 cap;
1569
1570         if (IS_ERR_OR_NULL(dev)) {
1571                 ret = -EINVAL;
1572                 goto failed;
1573         }
1574
1575         nr_opp = dev_pm_opp_get_opp_count(dev);
1576         if (nr_opp <= 0) {
1577                 ret = -EINVAL;
1578                 goto failed;
1579         }
1580
1581         /* First, try to find more precised Energy Model in DT */
1582         if (_of_has_opp_microwatt_property(dev)) {
1583                 EM_SET_ACTIVE_POWER_CB(em_cb, _get_dt_power);
1584                 goto register_em;
1585         }
1586
1587         np = of_node_get(dev->of_node);
1588         if (!np) {
1589                 ret = -EINVAL;
1590                 goto failed;
1591         }
1592
1593         /*
1594          * Register an EM only if the 'dynamic-power-coefficient' property is
1595          * set in devicetree. It is assumed the voltage values are known if that
1596          * property is set since it is useless otherwise. If voltages are not
1597          * known, just let the EM registration fail with an error to alert the
1598          * user about the inconsistent configuration.
1599          */
1600         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1601         of_node_put(np);
1602         if (ret || !cap) {
1603                 dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
1604                 ret = -EINVAL;
1605                 goto failed;
1606         }
1607
1608         EM_SET_ACTIVE_POWER_CB(em_cb, _get_power);
1609
1610 register_em:
1611         ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
1612         if (ret)
1613                 goto failed;
1614
1615         return 0;
1616
1617 failed:
1618         dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
1619         return ret;
1620 }
1621 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);