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         struct device_node *required_np;
  99
 100         required_np = of_parse_phandle(np, "required-opps", index);
 101         if (unlikely(!required_np)) {
 102                 pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",
 103                        __func__, np, index);
 104         }
 105
 106         return required_np;
 107 }
 108
 109 /* The caller must call dev_pm_opp_put_opp_table() after the table is used */
 110 static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
 111 {
 112         struct opp_table *opp_table;
 113         struct device_node *opp_table_np;
 114
 115         opp_table_np = of_get_parent(opp_np);
 116         if (!opp_table_np)
 117                 goto err;
 118
 119         /* It is safe to put the node now as all we need now is its address */
 120         of_node_put(opp_table_np);
 121
 122         mutex_lock(&opp_table_lock);
 123         list_for_each_entry(opp_table, &opp_tables, node) {
 124                 if (opp_table_np == opp_table->np) {
 125                         _get_opp_table_kref(opp_table);
 126                         mutex_unlock(&opp_table_lock);
 127                         return opp_table;
 128                 }
 129         }
 130         mutex_unlock(&opp_table_lock);
 131
 132 err:
 133         return ERR_PTR(-ENODEV);
 134 }
 135
 136 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
 137 static void _opp_table_free_required_tables(struct opp_table *opp_table)
 138 {
 139         struct opp_table **required_opp_tables = opp_table->required_opp_tables;
 140         int i;
 141
 142         if (!required_opp_tables)
 143                 return;
 144
 145         for (i = 0; i < opp_table->required_opp_count; i++) {
 146                 if (IS_ERR_OR_NULL(required_opp_tables[i]))
 147                         continue;
 148
 149                 dev_pm_opp_put_opp_table(required_opp_tables[i]);
 150         }
 151
 152         kfree(required_opp_tables);
 153
 154         opp_table->required_opp_count = 0;
 155         opp_table->required_opp_tables = NULL;
 156         list_del(&opp_table->lazy);
 157 }
 158
 159 /*
 160  * Populate all devices and opp tables which are part of "required-opps" list.
 161  * Checking only the first OPP node should be enough.
 162  */
 163 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
 164                                              struct device *dev,
 165                                              struct device_node *opp_np)
 166 {
 167         struct opp_table **required_opp_tables;
 168         struct device_node *required_np, *np;
 169         bool lazy = false;
 170         int count, i;
 171
 172         /* Traversing the first OPP node is all we need */
 173         np = of_get_next_available_child(opp_np, NULL);
 174         if (!np) {
 175                 dev_warn(dev, "Empty OPP table\n");
 176
 177                 return;
 178         }
 179
 180         count = of_count_phandle_with_args(np, "required-opps", NULL);
 181         if (!count)
 182                 goto put_np;
 183
 184         required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
 185                                       GFP_KERNEL);
 186         if (!required_opp_tables)
 187                 goto put_np;
 188
 189         opp_table->required_opp_tables = required_opp_tables;
 190         opp_table->required_opp_count = count;
 191
 192         for (i = 0; i < count; i++) {
 193                 required_np = of_parse_required_opp(np, i);
 194                 if (!required_np)
 195                         goto free_required_tables;
 196
 197                 required_opp_tables[i] = _find_table_of_opp_np(required_np);
 198                 of_node_put(required_np);
 199
 200                 if (IS_ERR(required_opp_tables[i])) {
 201                         lazy = true;
 202                         continue;
 203                 }
 204
 205                 /*
 206                  * We only support genpd's OPPs in the "required-opps" for now,
 207                  * as we don't know how much about other cases. Error out if the
 208                  * required OPP doesn't belong to a genpd.
 209                  */
 210                 if (!required_opp_tables[i]->is_genpd) {
 211                         dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
 212                                 required_np);
 213                         goto free_required_tables;
 214                 }
 215         }
 216
 217         /* Let's do the linking later on */
 218         if (lazy)
 219                 list_add(&opp_table->lazy, &lazy_opp_tables);
 220
 221         goto put_np;
 222
 223 free_required_tables:
 224         _opp_table_free_required_tables(opp_table);
 225 put_np:
 226         of_node_put(np);
 227 }
 228
 229 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
 230                         int index)
 231 {
 232         struct device_node *np, *opp_np;
 233         u32 val;
 234
 235         /*
 236          * Only required for backward compatibility with v1 bindings, but isn't
 237          * harmful for other cases. And so we do it unconditionally.
 238          */
 239         np = of_node_get(dev->of_node);
 240         if (!np)
 241                 return;
 242
 243         if (!of_property_read_u32(np, "clock-latency", &val))
 244                 opp_table->clock_latency_ns_max = val;
 245         of_property_read_u32(np, "voltage-tolerance",
 246                              &opp_table->voltage_tolerance_v1);
 247
 248         if (of_find_property(np, "#power-domain-cells", NULL))
 249                 opp_table->is_genpd = true;
 250
 251         /* Get OPP table node */
 252         opp_np = _opp_of_get_opp_desc_node(np, index);
 253         of_node_put(np);
 254
 255         if (!opp_np)
 256                 return;
 257
 258         if (of_property_read_bool(opp_np, "opp-shared"))
 259                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
 260         else
 261                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
 262
 263         opp_table->np = opp_np;
 264
 265         _opp_table_alloc_required_tables(opp_table, dev, opp_np);
 266         of_node_put(opp_np);
 267 }
 268
 269 void _of_clear_opp_table(struct opp_table *opp_table)
 270 {
 271         _opp_table_free_required_tables(opp_table);
 272 }
 273
 274 /*
 275  * Release all resources previously acquired with a call to
 276  * _of_opp_alloc_required_opps().
 277  */
 278 void _of_opp_free_required_opps(struct opp_table *opp_table,
 279                                 struct dev_pm_opp *opp)
 280 {
 281         struct dev_pm_opp **required_opps = opp->required_opps;
 282         int i;
 283
 284         if (!required_opps)
 285                 return;
 286
 287         for (i = 0; i < opp_table->required_opp_count; i++) {
 288                 if (!required_opps[i])
 289                         continue;
 290
 291                 /* Put the reference back */
 292                 dev_pm_opp_put(required_opps[i]);
 293         }
 294
 295         opp->required_opps = NULL;
 296         kfree(required_opps);
 297 }
 298
 299 /* Populate all required OPPs which are part of "required-opps" list */
 300 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
 301                                        struct dev_pm_opp *opp)
 302 {
 303         struct dev_pm_opp **required_opps;
 304         struct opp_table *required_table;
 305         struct device_node *np;
 306         int i, ret, count = opp_table->required_opp_count;
 307
 308         if (!count)
 309                 return 0;
 310
 311         required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
 312         if (!required_opps)
 313                 return -ENOMEM;
 314
 315         opp->required_opps = required_opps;
 316
 317         for (i = 0; i < count; i++) {
 318                 required_table = opp_table->required_opp_tables[i];
 319
 320                 /* Required table not added yet, we will link later */
 321                 if (IS_ERR_OR_NULL(required_table))
 322                         continue;
 323
 324                 np = of_parse_required_opp(opp->np, i);
 325                 if (unlikely(!np)) {
 326                         ret = -ENODEV;
 327                         goto free_required_opps;
 328                 }
 329
 330                 required_opps[i] = _find_opp_of_np(required_table, np);
 331                 of_node_put(np);
 332
 333                 if (!required_opps[i]) {
 334                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
 335                                __func__, opp->np, i);
 336                         ret = -ENODEV;
 337                         goto free_required_opps;
 338                 }
 339         }
 340
 341         return 0;
 342
 343 free_required_opps:
 344         _of_opp_free_required_opps(opp_table, opp);
 345
 346         return ret;
 347 }
 348
 349 /* Link required OPPs for an individual OPP */
 350 static int lazy_link_required_opps(struct opp_table *opp_table,
 351                                    struct opp_table *new_table, int index)
 352 {
 353         struct device_node *required_np;
 354         struct dev_pm_opp *opp;
 355
 356         list_for_each_entry(opp, &opp_table->opp_list, node) {
 357                 required_np = of_parse_required_opp(opp->np, index);
 358                 if (unlikely(!required_np))
 359                         return -ENODEV;
 360
 361                 opp->required_opps[index] = _find_opp_of_np(new_table, required_np);
 362                 of_node_put(required_np);
 363
 364                 if (!opp->required_opps[index]) {
 365                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
 366                                __func__, opp->np, index);
 367                         return -ENODEV;
 368                 }
 369         }
 370
 371         return 0;
 372 }
 373
 374 /* Link required OPPs for all OPPs of the newly added OPP table */
 375 static void lazy_link_required_opp_table(struct opp_table *new_table)
 376 {
 377         struct opp_table *opp_table, *temp, **required_opp_tables;
 378         struct device_node *required_np, *opp_np, *required_table_np;
 379         struct dev_pm_opp *opp;
 380         int i, ret;
 381
 382         /*
 383          * We only support genpd's OPPs in the "required-opps" for now,
 384          * as we don't know much about other cases.
 385          */
 386         if (!new_table->is_genpd)
 387                 return;
 388
 389         mutex_lock(&opp_table_lock);
 390
 391         list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
 392                 bool lazy = false;
 393
 394                 /* opp_np can't be invalid here */
 395                 opp_np = of_get_next_available_child(opp_table->np, NULL);
 396
 397                 for (i = 0; i < opp_table->required_opp_count; i++) {
 398                         required_opp_tables = opp_table->required_opp_tables;
 399
 400                         /* Required opp-table is already parsed */
 401                         if (!IS_ERR(required_opp_tables[i]))
 402                                 continue;
 403
 404                         /* required_np can't be invalid here */
 405                         required_np = of_parse_required_opp(opp_np, i);
 406                         required_table_np = of_get_parent(required_np);
 407
 408                         of_node_put(required_table_np);
 409                         of_node_put(required_np);
 410
 411                         /*
 412                          * Newly added table isn't the required opp-table for
 413                          * opp_table.
 414                          */
 415                         if (required_table_np != new_table->np) {
 416                                 lazy = true;
 417                                 continue;
 418                         }
 419
 420                         required_opp_tables[i] = new_table;
 421                         _get_opp_table_kref(new_table);
 422
 423                         /* Link OPPs now */
 424                         ret = lazy_link_required_opps(opp_table, new_table, i);
 425                         if (ret) {
 426                                 /* The OPPs will be marked unusable */
 427                                 lazy = false;
 428                                 break;
 429                         }
 430                 }
 431
 432                 of_node_put(opp_np);
 433
 434                 /* All required opp-tables found, remove from lazy list */
 435                 if (!lazy) {
 436                         list_del(&opp_table->lazy);
 437                         INIT_LIST_HEAD(&opp_table->lazy);
 438
 439                         list_for_each_entry(opp, &opp_table->opp_list, node)
 440                                 _required_opps_available(opp, opp_table->required_opp_count);
 441                 }
 442         }
 443
 444         mutex_unlock(&opp_table_lock);
 445 }
 446
 447 static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
 448 {
 449         struct device_node *np, *opp_np;
 450         struct property *prop;
 451
 452         if (!opp_table) {
 453                 np = of_node_get(dev->of_node);
 454                 if (!np)
 455                         return -ENODEV;
 456
 457                 opp_np = _opp_of_get_opp_desc_node(np, 0);
 458                 of_node_put(np);
 459         } else {
 460                 opp_np = of_node_get(opp_table->np);
 461         }
 462
 463         /* Lets not fail in case we are parsing opp-v1 bindings */
 464         if (!opp_np)
 465                 return 0;
 466
 467         /* Checking only first OPP is sufficient */
 468         np = of_get_next_available_child(opp_np, NULL);
 469         if (!np) {
 470                 dev_err(dev, "OPP table empty\n");
 471                 return -EINVAL;
 472         }
 473         of_node_put(opp_np);
 474
 475         prop = of_find_property(np, "opp-peak-kBps", NULL);
 476         of_node_put(np);
 477
 478         if (!prop || !prop->length)
 479                 return 0;
 480
 481         return 1;
 482 }
 483
 484 int dev_pm_opp_of_find_icc_paths(struct device *dev,
 485                                  struct opp_table *opp_table)
 486 {
 487         struct device_node *np;
 488         int ret, i, count, num_paths;
 489         struct icc_path **paths;
 490
 491         ret = _bandwidth_supported(dev, opp_table);
 492         if (ret == -EINVAL)
 493                 return 0; /* Empty OPP table is a valid corner-case, let's not fail */
 494         else if (ret <= 0)
 495                 return ret;
 496
 497         ret = 0;
 498
 499         np = of_node_get(dev->of_node);
 500         if (!np)
 501                 return 0;
 502
 503         count = of_count_phandle_with_args(np, "interconnects",
 504                                            "#interconnect-cells");
 505         of_node_put(np);
 506         if (count < 0)
 507                 return 0;
 508
 509         /* two phandles when #interconnect-cells = <1> */
 510         if (count % 2) {
 511                 dev_err(dev, "%s: Invalid interconnects values\n", __func__);
 512                 return -EINVAL;
 513         }
 514
 515         num_paths = count / 2;
 516         paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
 517         if (!paths)
 518                 return -ENOMEM;
 519
 520         for (i = 0; i < num_paths; i++) {
 521                 paths[i] = of_icc_get_by_index(dev, i);
 522                 if (IS_ERR(paths[i])) {
 523                         ret = PTR_ERR(paths[i]);
 524                         if (ret != -EPROBE_DEFER) {
 525                                 dev_err(dev, "%s: Unable to get path%d: %d\n",
 526                                         __func__, i, ret);
 527                         }
 528                         goto err;
 529                 }
 530         }
 531
 532         if (opp_table) {
 533                 opp_table->paths = paths;
 534                 opp_table->path_count = num_paths;
 535                 return 0;
 536         }
 537
 538 err:
 539         while (i--)
 540                 icc_put(paths[i]);
 541
 542         kfree(paths);
 543
 544         return ret;
 545 }
 546 EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);
 547
 548 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
 549                               struct device_node *np)
 550 {
 551         unsigned int levels = opp_table->supported_hw_count;
 552         int count, versions, ret, i, j;
 553         u32 val;
 554
 555         if (!opp_table->supported_hw) {
 556                 /*
 557                  * In the case that no supported_hw has been set by the
 558                  * platform but there is an opp-supported-hw value set for
 559                  * an OPP then the OPP should not be enabled as there is
 560                  * no way to see if the hardware supports it.
 561                  */
 562                 if (of_find_property(np, "opp-supported-hw", NULL))
 563                         return false;
 564                 else
 565                         return true;
 566         }
 567
 568         count = of_property_count_u32_elems(np, "opp-supported-hw");
 569         if (count <= 0 || count % levels) {
 570                 dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
 571                         __func__, count);
 572                 return false;
 573         }
 574
 575         versions = count / levels;
 576
 577         /* All levels in at least one of the versions should match */
 578         for (i = 0; i < versions; i++) {
 579                 bool supported = true;
 580
 581                 for (j = 0; j < levels; j++) {
 582                         ret = of_property_read_u32_index(np, "opp-supported-hw",
 583                                                          i * levels + j, &val);
 584                         if (ret) {
 585                                 dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
 586                                          __func__, i * levels + j, ret);
 587                                 return false;
 588                         }
 589
 590                         /* Check if the level is supported */
 591                         if (!(val & opp_table->supported_hw[j])) {
 592                                 supported = false;
 593                                 break;
 594                         }
 595                 }
 596
 597                 if (supported)
 598                         return true;
 599         }
 600
 601         return false;
 602 }
 603
 604 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 605                               struct opp_table *opp_table)
 606 {
 607         u32 *microvolt, *microamp = NULL;
 608         int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
 609         struct property *prop = NULL;
 610         char name[NAME_MAX];
 611
 612         /* Search for "opp-microvolt-<name>" */
 613         if (opp_table->prop_name) {
 614                 snprintf(name, sizeof(name), "opp-microvolt-%s",
 615                          opp_table->prop_name);
 616                 prop = of_find_property(opp->np, name, NULL);
 617         }
 618
 619         if (!prop) {
 620                 /* Search for "opp-microvolt" */
 621                 sprintf(name, "opp-microvolt");
 622                 prop = of_find_property(opp->np, name, NULL);
 623
 624                 /* Missing property isn't a problem, but an invalid entry is */
 625                 if (!prop) {
 626                         if (unlikely(supplies == -1)) {
 627                                 /* Initialize regulator_count */
 628                                 opp_table->regulator_count = 0;
 629                                 return 0;
 630                         }
 631
 632                         if (!supplies)
 633                                 return 0;
 634
 635                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
 636                                 __func__);
 637                         return -EINVAL;
 638                 }
 639         }
 640
 641         if (unlikely(supplies == -1)) {
 642                 /* Initialize regulator_count */
 643                 supplies = opp_table->regulator_count = 1;
 644         } else if (unlikely(!supplies)) {
 645                 dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
 646                 return -EINVAL;
 647         }
 648
 649         vcount = of_property_count_u32_elems(opp->np, name);
 650         if (vcount < 0) {
 651                 dev_err(dev, "%s: Invalid %s property (%d)\n",
 652                         __func__, name, vcount);
 653                 return vcount;
 654         }
 655
 656         /* There can be one or three elements per supply */
 657         if (vcount != supplies && vcount != supplies * 3) {
 658                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 659                         __func__, name, vcount, supplies);
 660                 return -EINVAL;
 661         }
 662
 663         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
 664         if (!microvolt)
 665                 return -ENOMEM;
 666
 667         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
 668         if (ret) {
 669                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 670                 ret = -EINVAL;
 671                 goto free_microvolt;
 672         }
 673
 674         /* Search for "opp-microamp-<name>" */
 675         prop = NULL;
 676         if (opp_table->prop_name) {
 677                 snprintf(name, sizeof(name), "opp-microamp-%s",
 678                          opp_table->prop_name);
 679                 prop = of_find_property(opp->np, name, NULL);
 680         }
 681
 682         if (!prop) {
 683                 /* Search for "opp-microamp" */
 684                 sprintf(name, "opp-microamp");
 685                 prop = of_find_property(opp->np, name, NULL);
 686         }
 687
 688         if (prop) {
 689                 icount = of_property_count_u32_elems(opp->np, name);
 690                 if (icount < 0) {
 691                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 692                                 name, icount);
 693                         ret = icount;
 694                         goto free_microvolt;
 695                 }
 696
 697                 if (icount != supplies) {
 698                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 699                                 __func__, name, icount, supplies);
 700                         ret = -EINVAL;
 701                         goto free_microvolt;
 702                 }
 703
 704                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
 705                 if (!microamp) {
 706                         ret = -EINVAL;
 707                         goto free_microvolt;
 708                 }
 709
 710                 ret = of_property_read_u32_array(opp->np, name, microamp,
 711                                                  icount);
 712                 if (ret) {
 713                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 714                                 name, ret);
 715                         ret = -EINVAL;
 716                         goto free_microamp;
 717                 }
 718         }
 719
 720         for (i = 0, j = 0; i < supplies; i++) {
 721                 opp->supplies[i].u_volt = microvolt[j++];
 722
 723                 if (vcount == supplies) {
 724                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
 725                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
 726                 } else {
 727                         opp->supplies[i].u_volt_min = microvolt[j++];
 728                         opp->supplies[i].u_volt_max = microvolt[j++];
 729                 }
 730
 731                 if (microamp)
 732                         opp->supplies[i].u_amp = microamp[i];
 733         }
 734
 735 free_microamp:
 736         kfree(microamp);
 737 free_microvolt:
 738         kfree(microvolt);
 739
 740         return ret;
 741 }
 742
 743 /**
 744  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 745  *                                entries
 746  * @dev:        device pointer used to lookup OPP table.
 747  *
 748  * Free OPPs created using static entries present in DT.
 749  */
 750 void dev_pm_opp_of_remove_table(struct device *dev)
 751 {
 752         dev_pm_opp_remove_table(dev);
 753 }
 754 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 755
 756 static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *table,
 757                     struct device_node *np, bool peak)
 758 {
 759         const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
 760         struct property *prop;
 761         int i, count, ret;
 762         u32 *bw;
 763
 764         prop = of_find_property(np, name, NULL);
 765         if (!prop)
 766                 return -ENODEV;
 767
 768         count = prop->length / sizeof(u32);
 769         if (table->path_count != count) {
 770                 pr_err("%s: Mismatch between %s and paths (%d %d)\n",
 771                                 __func__, name, count, table->path_count);
 772                 return -EINVAL;
 773         }
 774
 775         bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
 776         if (!bw)
 777                 return -ENOMEM;
 778
 779         ret = of_property_read_u32_array(np, name, bw, count);
 780         if (ret) {
 781                 pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
 782                 goto out;
 783         }
 784
 785         for (i = 0; i < count; i++) {
 786                 if (peak)
 787                         new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
 788                 else
 789                         new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
 790         }
 791
 792 out:
 793         kfree(bw);
 794         return ret;
 795 }
 796
 797 static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table,
 798                          struct device_node *np, bool *rate_not_available)
 799 {
 800         bool found = false;
 801         u64 rate;
 802         int ret;
 803
 804         ret = of_property_read_u64(np, "opp-hz", &rate);
 805         if (!ret) {
 806                 /*
 807                  * Rate is defined as an unsigned long in clk API, and so
 808                  * casting explicitly to its type. Must be fixed once rate is 64
 809                  * bit guaranteed in clk API.
 810                  */
 811                 new_opp->rate = (unsigned long)rate;
 812                 found = true;
 813         }
 814         *rate_not_available = !!ret;
 815
 816         /*
 817          * Bandwidth consists of peak and average (optional) values:
 818          * opp-peak-kBps = <path1_value path2_value>;
 819          * opp-avg-kBps = <path1_value path2_value>;
 820          */
 821         ret = _read_bw(new_opp, table, np, true);
 822         if (!ret) {
 823                 found = true;
 824                 ret = _read_bw(new_opp, table, np, false);
 825         }
 826
 827         /* The properties were found but we failed to parse them */
 828         if (ret && ret != -ENODEV)
 829                 return ret;
 830
 831         if (!of_property_read_u32(np, "opp-level", &new_opp->level))
 832                 found = true;
 833
 834         if (found)
 835                 return 0;
 836
 837         return ret;
 838 }
 839
 840 /**
 841  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 842  * @opp_table:  OPP table
 843  * @dev:        device for which we do this operation
 844  * @np:         device node
 845  *
 846  * This function adds an opp definition to the opp table and returns status. The
 847  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 848  * removed by dev_pm_opp_remove.
 849  *
 850  * Return:
 851  * Valid OPP pointer:
 852  *              On success
 853  * NULL:
 854  *              Duplicate OPPs (both freq and volt are same) and opp->available
 855  *              OR if the OPP is not supported by hardware.
 856  * ERR_PTR(-EEXIST):
 857  *              Freq are same and volt are different OR
 858  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 859  * ERR_PTR(-ENOMEM):
 860  *              Memory allocation failure
 861  * ERR_PTR(-EINVAL):
 862  *              Failed parsing the OPP node
 863  */
 864 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 865                 struct device *dev, struct device_node *np)
 866 {
 867         struct dev_pm_opp *new_opp;
 868         u32 val;
 869         int ret;
 870         bool rate_not_available = false;
 871
 872         new_opp = _opp_allocate(opp_table);
 873         if (!new_opp)
 874                 return ERR_PTR(-ENOMEM);
 875
 876         ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
 877         if (ret < 0 && !opp_table->is_genpd) {
 878                 dev_err(dev, "%s: opp key field not found\n", __func__);
 879                 goto free_opp;
 880         }
 881
 882         /* Check if the OPP supports hardware's hierarchy of versions or not */
 883         if (!_opp_is_supported(dev, opp_table, np)) {
 884                 dev_dbg(dev, "OPP not supported by hardware: %lu\n",
 885                         new_opp->rate);
 886                 goto free_opp;
 887         }
 888
 889         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 890
 891         new_opp->np = np;
 892         new_opp->dynamic = false;
 893         new_opp->available = true;
 894
 895         ret = _of_opp_alloc_required_opps(opp_table, new_opp);
 896         if (ret)
 897                 goto free_opp;
 898
 899         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 900                 new_opp->clock_latency_ns = val;
 901
 902         ret = opp_parse_supplies(new_opp, dev, opp_table);
 903         if (ret)
 904                 goto free_required_opps;
 905
 906         if (opp_table->is_genpd)
 907                 new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
 908
 909         ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
 910         if (ret) {
 911                 /* Don't return error for duplicate OPPs */
 912                 if (ret == -EBUSY)
 913                         ret = 0;
 914                 goto free_required_opps;
 915         }
 916
 917         /* OPP to select on device suspend */
 918         if (of_property_read_bool(np, "opp-suspend")) {
 919                 if (opp_table->suspend_opp) {
 920                         /* Pick the OPP with higher rate as suspend OPP */
 921                         if (new_opp->rate > opp_table->suspend_opp->rate) {
 922                                 opp_table->suspend_opp->suspend = false;
 923                                 new_opp->suspend = true;
 924                                 opp_table->suspend_opp = new_opp;
 925                         }
 926                 } else {
 927                         new_opp->suspend = true;
 928                         opp_table->suspend_opp = new_opp;
 929                 }
 930         }
 931
 932         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 933                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 934
 935         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu level:%u\n",
 936                  __func__, new_opp->turbo, new_opp->rate,
 937                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 938                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns,
 939                  new_opp->level);
 940
 941         /*
 942          * Notify the changes in the availability of the operable
 943          * frequency/voltage list.
 944          */
 945         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
 946         return new_opp;
 947
 948 free_required_opps:
 949         _of_opp_free_required_opps(opp_table, new_opp);
 950 free_opp:
 951         _opp_free(new_opp);
 952
 953         return ERR_PTR(ret);
 954 }
 955
 956 /* Initializes OPP tables based on new bindings */
 957 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 958 {
 959         struct device_node *np;
 960         int ret, count = 0;
 961         struct dev_pm_opp *opp;
 962
 963         /* OPP table is already initialized for the device */
 964         mutex_lock(&opp_table->lock);
 965         if (opp_table->parsed_static_opps) {
 966                 opp_table->parsed_static_opps++;
 967                 mutex_unlock(&opp_table->lock);
 968                 return 0;
 969         }
 970
 971         opp_table->parsed_static_opps = 1;
 972         mutex_unlock(&opp_table->lock);
 973
 974         /* We have opp-table node now, iterate over it and add OPPs */
 975         for_each_available_child_of_node(opp_table->np, np) {
 976                 opp = _opp_add_static_v2(opp_table, dev, np);
 977                 if (IS_ERR(opp)) {
 978                         ret = PTR_ERR(opp);
 979                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 980                                 ret);
 981                         of_node_put(np);
 982                         goto remove_static_opp;
 983                 } else if (opp) {
 984                         count++;
 985                 }
 986         }
 987
 988         /* There should be one of more OPP defined */
 989         if (WARN_ON(!count)) {
 990                 ret = -ENOENT;
 991                 goto remove_static_opp;
 992         }
 993
 994         list_for_each_entry(opp, &opp_table->opp_list, node) {
 995                 /* Any non-zero performance state would enable the feature */
 996                 if (opp->pstate) {
 997                         opp_table->genpd_performance_state = true;
 998                         break;
 999                 }
1000         }
1001
1002         lazy_link_required_opp_table(opp_table);
1003
1004         return 0;
1005
1006 remove_static_opp:
1007         _opp_remove_all_static(opp_table);
1008
1009         return ret;
1010 }
1011
1012 /* Initializes OPP tables based on old-deprecated bindings */
1013 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
1014 {
1015         const struct property *prop;
1016         const __be32 *val;
1017         int nr, ret = 0;
1018
1019         mutex_lock(&opp_table->lock);
1020         if (opp_table->parsed_static_opps) {
1021                 opp_table->parsed_static_opps++;
1022                 mutex_unlock(&opp_table->lock);
1023                 return 0;
1024         }
1025
1026         opp_table->parsed_static_opps = 1;
1027         mutex_unlock(&opp_table->lock);
1028
1029         prop = of_find_property(dev->of_node, "operating-points", NULL);
1030         if (!prop) {
1031                 ret = -ENODEV;
1032                 goto remove_static_opp;
1033         }
1034         if (!prop->value) {
1035                 ret = -ENODATA;
1036                 goto remove_static_opp;
1037         }
1038
1039         /*
1040          * Each OPP is a set of tuples consisting of frequency and
1041          * voltage like <freq-kHz vol-uV>.
1042          */
1043         nr = prop->length / sizeof(u32);
1044         if (nr % 2) {
1045                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
1046                 ret = -EINVAL;
1047                 goto remove_static_opp;
1048         }
1049
1050         val = prop->value;
1051         while (nr) {
1052                 unsigned long freq = be32_to_cpup(val++) * 1000;
1053                 unsigned long volt = be32_to_cpup(val++);
1054
1055                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
1056                 if (ret) {
1057                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
1058                                 __func__, freq, ret);
1059                         goto remove_static_opp;
1060                 }
1061                 nr -= 2;
1062         }
1063
1064         return 0;
1065
1066 remove_static_opp:
1067         _opp_remove_all_static(opp_table);
1068
1069         return ret;
1070 }
1071
1072 static int _of_add_table_indexed(struct device *dev, int index, bool getclk)
1073 {
1074         struct opp_table *opp_table;
1075         int ret, count;
1076
1077         if (index) {
1078                 /*
1079                  * If only one phandle is present, then the same OPP table
1080                  * applies for all index requests.
1081                  */
1082                 count = of_count_phandle_with_args(dev->of_node,
1083                                                    "operating-points-v2", NULL);
1084                 if (count == 1)
1085                         index = 0;
1086         }
1087
1088         opp_table = _add_opp_table_indexed(dev, index, getclk);
1089         if (IS_ERR(opp_table))
1090                 return PTR_ERR(opp_table);
1091
1092         /*
1093          * OPPs have two version of bindings now. Also try the old (v1)
1094          * bindings for backward compatibility with older dtbs.
1095          */
1096         if (opp_table->np)
1097                 ret = _of_add_opp_table_v2(dev, opp_table);
1098         else
1099                 ret = _of_add_opp_table_v1(dev, opp_table);
1100
1101         if (ret)
1102                 dev_pm_opp_put_opp_table(opp_table);
1103
1104         return ret;
1105 }
1106
1107 /**
1108  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
1109  * @dev:        device pointer used to lookup OPP table.
1110  *
1111  * Register the initial OPP table with the OPP library for given device.
1112  *
1113  * Return:
1114  * 0            On success OR
1115  *              Duplicate OPPs (both freq and volt are same) and opp->available
1116  * -EEXIST      Freq are same and volt are different OR
1117  *              Duplicate OPPs (both freq and volt are same) and !opp->available
1118  * -ENOMEM      Memory allocation failure
1119  * -ENODEV      when 'operating-points' property is not found or is invalid data
1120  *              in device node.
1121  * -ENODATA     when empty 'operating-points' property is found
1122  * -EINVAL      when invalid entries are found in opp-v2 table
1123  */
1124 int dev_pm_opp_of_add_table(struct device *dev)
1125 {
1126         return _of_add_table_indexed(dev, 0, true);
1127 }
1128 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
1129
1130 /**
1131  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1132  * @dev:        device pointer used to lookup OPP table.
1133  * @index:      Index number.
1134  *
1135  * Register the initial OPP table with the OPP library for given device only
1136  * using the "operating-points-v2" property.
1137  *
1138  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1139  */
1140 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
1141 {
1142         return _of_add_table_indexed(dev, index, true);
1143 }
1144 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
1145
1146 /**
1147  * dev_pm_opp_of_add_table_noclk() - Initialize indexed opp table from device
1148  *              tree without getting clk for device.
1149  * @dev:        device pointer used to lookup OPP table.
1150  * @index:      Index number.
1151  *
1152  * Register the initial OPP table with the OPP library for given device only
1153  * using the "operating-points-v2" property. Do not try to get the clk for the
1154  * device.
1155  *
1156  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1157  */
1158 int dev_pm_opp_of_add_table_noclk(struct device *dev, int index)
1159 {
1160         return _of_add_table_indexed(dev, index, false);
1161 }
1162 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_noclk);
1163
1164 /* CPU device specific helpers */
1165
1166 /**
1167  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
1168  * @cpumask:    cpumask for which OPP table needs to be removed
1169  *
1170  * This removes the OPP tables for CPUs present in the @cpumask.
1171  * This should be used only to remove static entries created from DT.
1172  */
1173 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
1174 {
1175         _dev_pm_opp_cpumask_remove_table(cpumask, -1);
1176 }
1177 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
1178
1179 /**
1180  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
1181  * @cpumask:    cpumask for which OPP table needs to be added.
1182  *
1183  * This adds the OPP tables for CPUs present in the @cpumask.
1184  */
1185 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
1186 {
1187         struct device *cpu_dev;
1188         int cpu, ret;
1189
1190         if (WARN_ON(cpumask_empty(cpumask)))
1191                 return -ENODEV;
1192
1193         for_each_cpu(cpu, cpumask) {
1194                 cpu_dev = get_cpu_device(cpu);
1195                 if (!cpu_dev) {
1196                         pr_err("%s: failed to get cpu%d device\n", __func__,
1197                                cpu);
1198                         ret = -ENODEV;
1199                         goto remove_table;
1200                 }
1201
1202                 ret = dev_pm_opp_of_add_table(cpu_dev);
1203                 if (ret) {
1204                         /*
1205                          * OPP may get registered dynamically, don't print error
1206                          * message here.
1207                          */
1208                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
1209                                  __func__, cpu, ret);
1210
1211                         goto remove_table;
1212                 }
1213         }
1214
1215         return 0;
1216
1217 remove_table:
1218         /* Free all other OPPs */
1219         _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
1220
1221         return ret;
1222 }
1223 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
1224
1225 /*
1226  * Works only for OPP v2 bindings.
1227  *
1228  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
1229  */
1230 /**
1231  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
1232  *                                    @cpu_dev using operating-points-v2
1233  *                                    bindings.
1234  *
1235  * @cpu_dev:    CPU device for which we do this operation
1236  * @cpumask:    cpumask to update with information of sharing CPUs
1237  *
1238  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
1239  *
1240  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
1241  */
1242 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
1243                                    struct cpumask *cpumask)
1244 {
1245         struct device_node *np, *tmp_np, *cpu_np;
1246         int cpu, ret = 0;
1247
1248         /* Get OPP descriptor node */
1249         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
1250         if (!np) {
1251                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
1252                 return -ENOENT;
1253         }
1254
1255         cpumask_set_cpu(cpu_dev->id, cpumask);
1256
1257         /* OPPs are shared ? */
1258         if (!of_property_read_bool(np, "opp-shared"))
1259                 goto put_cpu_node;
1260
1261         for_each_possible_cpu(cpu) {
1262                 if (cpu == cpu_dev->id)
1263                         continue;
1264
1265                 cpu_np = of_cpu_device_node_get(cpu);
1266                 if (!cpu_np) {
1267                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
1268                                 __func__, cpu);
1269                         ret = -ENOENT;
1270                         goto put_cpu_node;
1271                 }
1272
1273                 /* Get OPP descriptor node */
1274                 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
1275                 of_node_put(cpu_np);
1276                 if (!tmp_np) {
1277                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
1278                         ret = -ENOENT;
1279                         goto put_cpu_node;
1280                 }
1281
1282                 /* CPUs are sharing opp node */
1283                 if (np == tmp_np)
1284                         cpumask_set_cpu(cpu, cpumask);
1285
1286                 of_node_put(tmp_np);
1287         }
1288
1289 put_cpu_node:
1290         of_node_put(np);
1291         return ret;
1292 }
1293 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
1294
1295 /**
1296  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
1297  * @np: Node that contains the "required-opps" property.
1298  * @index: Index of the phandle to parse.
1299  *
1300  * Returns the performance state of the OPP pointed out by the "required-opps"
1301  * property at @index in @np.
1302  *
1303  * Return: Zero or positive performance state on success, otherwise negative
1304  * value on errors.
1305  */
1306 int of_get_required_opp_performance_state(struct device_node *np, int index)
1307 {
1308         struct dev_pm_opp *opp;
1309         struct device_node *required_np;
1310         struct opp_table *opp_table;
1311         int pstate = -EINVAL;
1312
1313         required_np = of_parse_required_opp(np, index);
1314         if (!required_np)
1315                 return -EINVAL;
1316
1317         opp_table = _find_table_of_opp_np(required_np);
1318         if (IS_ERR(opp_table)) {
1319                 pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
1320                        __func__, np, PTR_ERR(opp_table));
1321                 goto put_required_np;
1322         }
1323
1324         opp = _find_opp_of_np(opp_table, required_np);
1325         if (opp) {
1326                 pstate = opp->pstate;
1327                 dev_pm_opp_put(opp);
1328         }
1329
1330         dev_pm_opp_put_opp_table(opp_table);
1331
1332 put_required_np:
1333         of_node_put(required_np);
1334
1335         return pstate;
1336 }
1337 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1338
1339 /**
1340  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1341  * @opp:        opp for which DT node has to be returned for
1342  *
1343  * Return: DT node corresponding to the opp, else 0 on success.
1344  *
1345  * The caller needs to put the node with of_node_put() after using it.
1346  */
1347 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1348 {
1349         if (IS_ERR_OR_NULL(opp)) {
1350                 pr_err("%s: Invalid parameters\n", __func__);
1351                 return NULL;
1352         }
1353
1354         return of_node_get(opp->np);
1355 }
1356 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1357
1358 /*
1359  * Callback function provided to the Energy Model framework upon registration.
1360  * This computes the power estimated by @dev at @kHz if it is the frequency
1361  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1362  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1363  * frequency and @mW to the associated power. The power is estimated as
1364  * P = C * V^2 * f with C being the device's capacitance and V and f
1365  * respectively the voltage and frequency of the OPP.
1366  *
1367  * Returns -EINVAL if the power calculation failed because of missing
1368  * parameters, 0 otherwise.
1369  */
1370 static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz,
1371                                      struct device *dev)
1372 {
1373         struct dev_pm_opp *opp;
1374         struct device_node *np;
1375         unsigned long mV, Hz;
1376         u32 cap;
1377         u64 tmp;
1378         int ret;
1379
1380         np = of_node_get(dev->of_node);
1381         if (!np)
1382                 return -EINVAL;
1383
1384         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1385         of_node_put(np);
1386         if (ret)
1387                 return -EINVAL;
1388
1389         Hz = *kHz * 1000;
1390         opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
1391         if (IS_ERR(opp))
1392                 return -EINVAL;
1393
1394         mV = dev_pm_opp_get_voltage(opp) / 1000;
1395         dev_pm_opp_put(opp);
1396         if (!mV)
1397                 return -EINVAL;
1398
1399         tmp = (u64)cap * mV * mV * (Hz / 1000000);
1400         do_div(tmp, 1000000000);
1401
1402         *mW = (unsigned long)tmp;
1403         *kHz = Hz / 1000;
1404
1405         return 0;
1406 }
1407
1408 /**
1409  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1410  * @dev         : Device for which an Energy Model has to be registered
1411  * @cpus        : CPUs for which an Energy Model has to be registered. For
1412  *              other type of devices it should be set to NULL.
1413  *
1414  * This checks whether the "dynamic-power-coefficient" devicetree property has
1415  * been specified, and tries to register an Energy Model with it if it has.
1416  * Having this property means the voltages are known for OPPs and the EM
1417  * might be calculated.
1418  */
1419 int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
1420 {
1421         struct em_data_callback em_cb = EM_DATA_CB(_get_power);
1422         struct device_node *np;
1423         int ret, nr_opp;
1424         u32 cap;
1425
1426         if (IS_ERR_OR_NULL(dev)) {
1427                 ret = -EINVAL;
1428                 goto failed;
1429         }
1430
1431         nr_opp = dev_pm_opp_get_opp_count(dev);
1432         if (nr_opp <= 0) {
1433                 ret = -EINVAL;
1434                 goto failed;
1435         }
1436
1437         np = of_node_get(dev->of_node);
1438         if (!np) {
1439                 ret = -EINVAL;
1440                 goto failed;
1441         }
1442
1443         /*
1444          * Register an EM only if the 'dynamic-power-coefficient' property is
1445          * set in devicetree. It is assumed the voltage values are known if that
1446          * property is set since it is useless otherwise. If voltages are not
1447          * known, just let the EM registration fail with an error to alert the
1448          * user about the inconsistent configuration.
1449          */
1450         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1451         of_node_put(np);
1452         if (ret || !cap) {
1453                 dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
1454                 ret = -EINVAL;
1455                 goto failed;
1456         }
1457
1458         ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
1459         if (ret)
1460                 goto failed;
1461
1462         return 0;
1463
1464 failed:
1465         dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
1466         return ret;
1467 }
1468 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);