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)
 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         of_node_put(opp_np);
 246 }
 247
 248 void _of_clear_opp_table(struct opp_table *opp_table)
 249 {
 250         _opp_table_free_required_tables(opp_table);
 251 }
 252
 253 /*
 254  * Release all resources previously acquired with a call to
 255  * _of_opp_alloc_required_opps().
 256  */
 257 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 /* Populate all required OPPs which are part of "required-opps" list */
 279 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
 280                                        struct dev_pm_opp *opp)
 281 {
 282         struct dev_pm_opp **required_opps;
 283         struct opp_table *required_table;
 284         struct device_node *np;
 285         int i, ret, count = opp_table->required_opp_count;
 286
 287         if (!count)
 288                 return 0;
 289
 290         required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
 291         if (!required_opps)
 292                 return -ENOMEM;
 293
 294         opp->required_opps = required_opps;
 295
 296         for (i = 0; i < count; i++) {
 297                 required_table = opp_table->required_opp_tables[i];
 298
 299                 /* Required table not added yet, we will link later */
 300                 if (IS_ERR_OR_NULL(required_table))
 301                         continue;
 302
 303                 np = of_parse_required_opp(opp->np, i);
 304                 if (unlikely(!np)) {
 305                         ret = -ENODEV;
 306                         goto free_required_opps;
 307                 }
 308
 309                 required_opps[i] = _find_opp_of_np(required_table, np);
 310                 of_node_put(np);
 311
 312                 if (!required_opps[i]) {
 313                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
 314                                __func__, opp->np, i);
 315                         ret = -ENODEV;
 316                         goto free_required_opps;
 317                 }
 318         }
 319
 320         return 0;
 321
 322 free_required_opps:
 323         _of_opp_free_required_opps(opp_table, opp);
 324
 325         return ret;
 326 }
 327
 328 /* Link required OPPs for an individual OPP */
 329 static int lazy_link_required_opps(struct opp_table *opp_table,
 330                                    struct opp_table *new_table, int index)
 331 {
 332         struct device_node *required_np;
 333         struct dev_pm_opp *opp;
 334
 335         list_for_each_entry(opp, &opp_table->opp_list, node) {
 336                 required_np = of_parse_required_opp(opp->np, index);
 337                 if (unlikely(!required_np))
 338                         return -ENODEV;
 339
 340                 opp->required_opps[index] = _find_opp_of_np(new_table, required_np);
 341                 of_node_put(required_np);
 342
 343                 if (!opp->required_opps[index]) {
 344                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
 345                                __func__, opp->np, index);
 346                         return -ENODEV;
 347                 }
 348         }
 349
 350         return 0;
 351 }
 352
 353 /* Link required OPPs for all OPPs of the newly added OPP table */
 354 static void lazy_link_required_opp_table(struct opp_table *new_table)
 355 {
 356         struct opp_table *opp_table, *temp, **required_opp_tables;
 357         struct device_node *required_np, *opp_np, *required_table_np;
 358         struct dev_pm_opp *opp;
 359         int i, ret;
 360
 361         mutex_lock(&opp_table_lock);
 362
 363         list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
 364                 bool lazy = false;
 365
 366                 /* opp_np can't be invalid here */
 367                 opp_np = of_get_next_available_child(opp_table->np, NULL);
 368
 369                 for (i = 0; i < opp_table->required_opp_count; i++) {
 370                         required_opp_tables = opp_table->required_opp_tables;
 371
 372                         /* Required opp-table is already parsed */
 373                         if (!IS_ERR(required_opp_tables[i]))
 374                                 continue;
 375
 376                         /* required_np can't be invalid here */
 377                         required_np = of_parse_required_opp(opp_np, i);
 378                         required_table_np = of_get_parent(required_np);
 379
 380                         of_node_put(required_table_np);
 381                         of_node_put(required_np);
 382
 383                         /*
 384                          * Newly added table isn't the required opp-table for
 385                          * opp_table.
 386                          */
 387                         if (required_table_np != new_table->np) {
 388                                 lazy = true;
 389                                 continue;
 390                         }
 391
 392                         required_opp_tables[i] = new_table;
 393                         _get_opp_table_kref(new_table);
 394
 395                         /* Link OPPs now */
 396                         ret = lazy_link_required_opps(opp_table, new_table, i);
 397                         if (ret) {
 398                                 /* The OPPs will be marked unusable */
 399                                 lazy = false;
 400                                 break;
 401                         }
 402                 }
 403
 404                 of_node_put(opp_np);
 405
 406                 /* All required opp-tables found, remove from lazy list */
 407                 if (!lazy) {
 408                         list_del_init(&opp_table->lazy);
 409
 410                         list_for_each_entry(opp, &opp_table->opp_list, node)
 411                                 _required_opps_available(opp, opp_table->required_opp_count);
 412                 }
 413         }
 414
 415         mutex_unlock(&opp_table_lock);
 416 }
 417
 418 static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
 419 {
 420         struct device_node *np, *opp_np;
 421         struct property *prop;
 422
 423         if (!opp_table) {
 424                 np = of_node_get(dev->of_node);
 425                 if (!np)
 426                         return -ENODEV;
 427
 428                 opp_np = _opp_of_get_opp_desc_node(np, 0);
 429                 of_node_put(np);
 430         } else {
 431                 opp_np = of_node_get(opp_table->np);
 432         }
 433
 434         /* Lets not fail in case we are parsing opp-v1 bindings */
 435         if (!opp_np)
 436                 return 0;
 437
 438         /* Checking only first OPP is sufficient */
 439         np = of_get_next_available_child(opp_np, NULL);
 440         if (!np) {
 441                 dev_err(dev, "OPP table empty\n");
 442                 return -EINVAL;
 443         }
 444         of_node_put(opp_np);
 445
 446         prop = of_find_property(np, "opp-peak-kBps", NULL);
 447         of_node_put(np);
 448
 449         if (!prop || !prop->length)
 450                 return 0;
 451
 452         return 1;
 453 }
 454
 455 int dev_pm_opp_of_find_icc_paths(struct device *dev,
 456                                  struct opp_table *opp_table)
 457 {
 458         struct device_node *np;
 459         int ret, i, count, num_paths;
 460         struct icc_path **paths;
 461
 462         ret = _bandwidth_supported(dev, opp_table);
 463         if (ret == -EINVAL)
 464                 return 0; /* Empty OPP table is a valid corner-case, let's not fail */
 465         else if (ret <= 0)
 466                 return ret;
 467
 468         ret = 0;
 469
 470         np = of_node_get(dev->of_node);
 471         if (!np)
 472                 return 0;
 473
 474         count = of_count_phandle_with_args(np, "interconnects",
 475                                            "#interconnect-cells");
 476         of_node_put(np);
 477         if (count < 0)
 478                 return 0;
 479
 480         /* two phandles when #interconnect-cells = <1> */
 481         if (count % 2) {
 482                 dev_err(dev, "%s: Invalid interconnects values\n", __func__);
 483                 return -EINVAL;
 484         }
 485
 486         num_paths = count / 2;
 487         paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
 488         if (!paths)
 489                 return -ENOMEM;
 490
 491         for (i = 0; i < num_paths; i++) {
 492                 paths[i] = of_icc_get_by_index(dev, i);
 493                 if (IS_ERR(paths[i])) {
 494                         ret = PTR_ERR(paths[i]);
 495                         if (ret != -EPROBE_DEFER) {
 496                                 dev_err(dev, "%s: Unable to get path%d: %d\n",
 497                                         __func__, i, ret);
 498                         }
 499                         goto err;
 500                 }
 501         }
 502
 503         if (opp_table) {
 504                 opp_table->paths = paths;
 505                 opp_table->path_count = num_paths;
 506                 return 0;
 507         }
 508
 509 err:
 510         while (i--)
 511                 icc_put(paths[i]);
 512
 513         kfree(paths);
 514
 515         return ret;
 516 }
 517 EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);
 518
 519 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
 520                               struct device_node *np)
 521 {
 522         unsigned int levels = opp_table->supported_hw_count;
 523         int count, versions, ret, i, j;
 524         u32 val;
 525
 526         if (!opp_table->supported_hw) {
 527                 /*
 528                  * In the case that no supported_hw has been set by the
 529                  * platform but there is an opp-supported-hw value set for
 530                  * an OPP then the OPP should not be enabled as there is
 531                  * no way to see if the hardware supports it.
 532                  */
 533                 if (of_find_property(np, "opp-supported-hw", NULL))
 534                         return false;
 535                 else
 536                         return true;
 537         }
 538
 539         count = of_property_count_u32_elems(np, "opp-supported-hw");
 540         if (count <= 0 || count % levels) {
 541                 dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
 542                         __func__, count);
 543                 return false;
 544         }
 545
 546         versions = count / levels;
 547
 548         /* All levels in at least one of the versions should match */
 549         for (i = 0; i < versions; i++) {
 550                 bool supported = true;
 551
 552                 for (j = 0; j < levels; j++) {
 553                         ret = of_property_read_u32_index(np, "opp-supported-hw",
 554                                                          i * levels + j, &val);
 555                         if (ret) {
 556                                 dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
 557                                          __func__, i * levels + j, ret);
 558                                 return false;
 559                         }
 560
 561                         /* Check if the level is supported */
 562                         if (!(val & opp_table->supported_hw[j])) {
 563                                 supported = false;
 564                                 break;
 565                         }
 566                 }
 567
 568                 if (supported)
 569                         return true;
 570         }
 571
 572         return false;
 573 }
 574
 575 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 576                               struct opp_table *opp_table)
 577 {
 578         u32 *microvolt, *microamp = NULL;
 579         int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
 580         struct property *prop = NULL;
 581         char name[NAME_MAX];
 582
 583         /* Search for "opp-microvolt-<name>" */
 584         if (opp_table->prop_name) {
 585                 snprintf(name, sizeof(name), "opp-microvolt-%s",
 586                          opp_table->prop_name);
 587                 prop = of_find_property(opp->np, name, NULL);
 588         }
 589
 590         if (!prop) {
 591                 /* Search for "opp-microvolt" */
 592                 sprintf(name, "opp-microvolt");
 593                 prop = of_find_property(opp->np, name, NULL);
 594
 595                 /* Missing property isn't a problem, but an invalid entry is */
 596                 if (!prop) {
 597                         if (unlikely(supplies == -1)) {
 598                                 /* Initialize regulator_count */
 599                                 opp_table->regulator_count = 0;
 600                                 return 0;
 601                         }
 602
 603                         if (!supplies)
 604                                 return 0;
 605
 606                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
 607                                 __func__);
 608                         return -EINVAL;
 609                 }
 610         }
 611
 612         if (unlikely(supplies == -1)) {
 613                 /* Initialize regulator_count */
 614                 supplies = opp_table->regulator_count = 1;
 615         } else if (unlikely(!supplies)) {
 616                 dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
 617                 return -EINVAL;
 618         }
 619
 620         vcount = of_property_count_u32_elems(opp->np, name);
 621         if (vcount < 0) {
 622                 dev_err(dev, "%s: Invalid %s property (%d)\n",
 623                         __func__, name, vcount);
 624                 return vcount;
 625         }
 626
 627         /* There can be one or three elements per supply */
 628         if (vcount != supplies && vcount != supplies * 3) {
 629                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 630                         __func__, name, vcount, supplies);
 631                 return -EINVAL;
 632         }
 633
 634         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
 635         if (!microvolt)
 636                 return -ENOMEM;
 637
 638         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
 639         if (ret) {
 640                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 641                 ret = -EINVAL;
 642                 goto free_microvolt;
 643         }
 644
 645         /* Search for "opp-microamp-<name>" */
 646         prop = NULL;
 647         if (opp_table->prop_name) {
 648                 snprintf(name, sizeof(name), "opp-microamp-%s",
 649                          opp_table->prop_name);
 650                 prop = of_find_property(opp->np, name, NULL);
 651         }
 652
 653         if (!prop) {
 654                 /* Search for "opp-microamp" */
 655                 sprintf(name, "opp-microamp");
 656                 prop = of_find_property(opp->np, name, NULL);
 657         }
 658
 659         if (prop) {
 660                 icount = of_property_count_u32_elems(opp->np, name);
 661                 if (icount < 0) {
 662                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 663                                 name, icount);
 664                         ret = icount;
 665                         goto free_microvolt;
 666                 }
 667
 668                 if (icount != supplies) {
 669                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 670                                 __func__, name, icount, supplies);
 671                         ret = -EINVAL;
 672                         goto free_microvolt;
 673                 }
 674
 675                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
 676                 if (!microamp) {
 677                         ret = -EINVAL;
 678                         goto free_microvolt;
 679                 }
 680
 681                 ret = of_property_read_u32_array(opp->np, name, microamp,
 682                                                  icount);
 683                 if (ret) {
 684                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 685                                 name, ret);
 686                         ret = -EINVAL;
 687                         goto free_microamp;
 688                 }
 689         }
 690
 691         for (i = 0, j = 0; i < supplies; i++) {
 692                 opp->supplies[i].u_volt = microvolt[j++];
 693
 694                 if (vcount == supplies) {
 695                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
 696                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
 697                 } else {
 698                         opp->supplies[i].u_volt_min = microvolt[j++];
 699                         opp->supplies[i].u_volt_max = microvolt[j++];
 700                 }
 701
 702                 if (microamp)
 703                         opp->supplies[i].u_amp = microamp[i];
 704         }
 705
 706 free_microamp:
 707         kfree(microamp);
 708 free_microvolt:
 709         kfree(microvolt);
 710
 711         return ret;
 712 }
 713
 714 /**
 715  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 716  *                                entries
 717  * @dev:        device pointer used to lookup OPP table.
 718  *
 719  * Free OPPs created using static entries present in DT.
 720  */
 721 void dev_pm_opp_of_remove_table(struct device *dev)
 722 {
 723         dev_pm_opp_remove_table(dev);
 724 }
 725 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 726
 727 static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *table,
 728                     struct device_node *np, bool peak)
 729 {
 730         const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
 731         struct property *prop;
 732         int i, count, ret;
 733         u32 *bw;
 734
 735         prop = of_find_property(np, name, NULL);
 736         if (!prop)
 737                 return -ENODEV;
 738
 739         count = prop->length / sizeof(u32);
 740         if (table->path_count != count) {
 741                 pr_err("%s: Mismatch between %s and paths (%d %d)\n",
 742                                 __func__, name, count, table->path_count);
 743                 return -EINVAL;
 744         }
 745
 746         bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
 747         if (!bw)
 748                 return -ENOMEM;
 749
 750         ret = of_property_read_u32_array(np, name, bw, count);
 751         if (ret) {
 752                 pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
 753                 goto out;
 754         }
 755
 756         for (i = 0; i < count; i++) {
 757                 if (peak)
 758                         new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
 759                 else
 760                         new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
 761         }
 762
 763 out:
 764         kfree(bw);
 765         return ret;
 766 }
 767
 768 static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table,
 769                          struct device_node *np, bool *rate_not_available)
 770 {
 771         bool found = false;
 772         u64 rate;
 773         int ret;
 774
 775         ret = of_property_read_u64(np, "opp-hz", &rate);
 776         if (!ret) {
 777                 /*
 778                  * Rate is defined as an unsigned long in clk API, and so
 779                  * casting explicitly to its type. Must be fixed once rate is 64
 780                  * bit guaranteed in clk API.
 781                  */
 782                 new_opp->rate = (unsigned long)rate;
 783                 found = true;
 784         }
 785         *rate_not_available = !!ret;
 786
 787         /*
 788          * Bandwidth consists of peak and average (optional) values:
 789          * opp-peak-kBps = <path1_value path2_value>;
 790          * opp-avg-kBps = <path1_value path2_value>;
 791          */
 792         ret = _read_bw(new_opp, table, np, true);
 793         if (!ret) {
 794                 found = true;
 795                 ret = _read_bw(new_opp, table, np, false);
 796         }
 797
 798         /* The properties were found but we failed to parse them */
 799         if (ret && ret != -ENODEV)
 800                 return ret;
 801
 802         if (!of_property_read_u32(np, "opp-level", &new_opp->level))
 803                 found = true;
 804
 805         if (found)
 806                 return 0;
 807
 808         return ret;
 809 }
 810
 811 /**
 812  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 813  * @opp_table:  OPP table
 814  * @dev:        device for which we do this operation
 815  * @np:         device node
 816  *
 817  * This function adds an opp definition to the opp table and returns status. The
 818  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 819  * removed by dev_pm_opp_remove.
 820  *
 821  * Return:
 822  * Valid OPP pointer:
 823  *              On success
 824  * NULL:
 825  *              Duplicate OPPs (both freq and volt are same) and opp->available
 826  *              OR if the OPP is not supported by hardware.
 827  * ERR_PTR(-EEXIST):
 828  *              Freq are same and volt are different OR
 829  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 830  * ERR_PTR(-ENOMEM):
 831  *              Memory allocation failure
 832  * ERR_PTR(-EINVAL):
 833  *              Failed parsing the OPP node
 834  */
 835 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 836                 struct device *dev, struct device_node *np)
 837 {
 838         struct dev_pm_opp *new_opp;
 839         u32 val;
 840         int ret;
 841         bool rate_not_available = false;
 842
 843         new_opp = _opp_allocate(opp_table);
 844         if (!new_opp)
 845                 return ERR_PTR(-ENOMEM);
 846
 847         ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
 848         if (ret < 0) {
 849                 dev_err(dev, "%s: opp key field not found\n", __func__);
 850                 goto free_opp;
 851         }
 852
 853         /* Check if the OPP supports hardware's hierarchy of versions or not */
 854         if (!_opp_is_supported(dev, opp_table, np)) {
 855                 dev_dbg(dev, "OPP not supported by hardware: %lu\n",
 856                         new_opp->rate);
 857                 goto free_opp;
 858         }
 859
 860         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 861
 862         new_opp->np = np;
 863         new_opp->dynamic = false;
 864         new_opp->available = true;
 865
 866         ret = _of_opp_alloc_required_opps(opp_table, new_opp);
 867         if (ret)
 868                 goto free_opp;
 869
 870         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 871                 new_opp->clock_latency_ns = val;
 872
 873         ret = opp_parse_supplies(new_opp, dev, opp_table);
 874         if (ret)
 875                 goto free_required_opps;
 876
 877         if (opp_table->is_genpd)
 878                 new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
 879
 880         ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
 881         if (ret) {
 882                 /* Don't return error for duplicate OPPs */
 883                 if (ret == -EBUSY)
 884                         ret = 0;
 885                 goto free_required_opps;
 886         }
 887
 888         /* OPP to select on device suspend */
 889         if (of_property_read_bool(np, "opp-suspend")) {
 890                 if (opp_table->suspend_opp) {
 891                         /* Pick the OPP with higher rate as suspend OPP */
 892                         if (new_opp->rate > opp_table->suspend_opp->rate) {
 893                                 opp_table->suspend_opp->suspend = false;
 894                                 new_opp->suspend = true;
 895                                 opp_table->suspend_opp = new_opp;
 896                         }
 897                 } else {
 898                         new_opp->suspend = true;
 899                         opp_table->suspend_opp = new_opp;
 900                 }
 901         }
 902
 903         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 904                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 905
 906         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu level:%u\n",
 907                  __func__, new_opp->turbo, new_opp->rate,
 908                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 909                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns,
 910                  new_opp->level);
 911
 912         /*
 913          * Notify the changes in the availability of the operable
 914          * frequency/voltage list.
 915          */
 916         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
 917         return new_opp;
 918
 919 free_required_opps:
 920         _of_opp_free_required_opps(opp_table, new_opp);
 921 free_opp:
 922         _opp_free(new_opp);
 923
 924         return ERR_PTR(ret);
 925 }
 926
 927 /* Initializes OPP tables based on new bindings */
 928 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 929 {
 930         struct device_node *np;
 931         int ret, count = 0;
 932         struct dev_pm_opp *opp;
 933
 934         /* OPP table is already initialized for the device */
 935         mutex_lock(&opp_table->lock);
 936         if (opp_table->parsed_static_opps) {
 937                 opp_table->parsed_static_opps++;
 938                 mutex_unlock(&opp_table->lock);
 939                 return 0;
 940         }
 941
 942         opp_table->parsed_static_opps = 1;
 943         mutex_unlock(&opp_table->lock);
 944
 945         /* We have opp-table node now, iterate over it and add OPPs */
 946         for_each_available_child_of_node(opp_table->np, np) {
 947                 opp = _opp_add_static_v2(opp_table, dev, np);
 948                 if (IS_ERR(opp)) {
 949                         ret = PTR_ERR(opp);
 950                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 951                                 ret);
 952                         of_node_put(np);
 953                         goto remove_static_opp;
 954                 } else if (opp) {
 955                         count++;
 956                 }
 957         }
 958
 959         /* There should be one or more OPPs defined */
 960         if (!count) {
 961                 dev_err(dev, "%s: no supported OPPs", __func__);
 962                 ret = -ENOENT;
 963                 goto remove_static_opp;
 964         }
 965
 966         list_for_each_entry(opp, &opp_table->opp_list, node) {
 967                 /* Any non-zero performance state would enable the feature */
 968                 if (opp->pstate) {
 969                         opp_table->genpd_performance_state = true;
 970                         break;
 971                 }
 972         }
 973
 974         lazy_link_required_opp_table(opp_table);
 975
 976         return 0;
 977
 978 remove_static_opp:
 979         _opp_remove_all_static(opp_table);
 980
 981         return ret;
 982 }
 983
 984 /* Initializes OPP tables based on old-deprecated bindings */
 985 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 986 {
 987         const struct property *prop;
 988         const __be32 *val;
 989         int nr, ret = 0;
 990
 991         mutex_lock(&opp_table->lock);
 992         if (opp_table->parsed_static_opps) {
 993                 opp_table->parsed_static_opps++;
 994                 mutex_unlock(&opp_table->lock);
 995                 return 0;
 996         }
 997
 998         opp_table->parsed_static_opps = 1;
 999         mutex_unlock(&opp_table->lock);
1000
1001         prop = of_find_property(dev->of_node, "operating-points", NULL);
1002         if (!prop) {
1003                 ret = -ENODEV;
1004                 goto remove_static_opp;
1005         }
1006         if (!prop->value) {
1007                 ret = -ENODATA;
1008                 goto remove_static_opp;
1009         }
1010
1011         /*
1012          * Each OPP is a set of tuples consisting of frequency and
1013          * voltage like <freq-kHz vol-uV>.
1014          */
1015         nr = prop->length / sizeof(u32);
1016         if (nr % 2) {
1017                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
1018                 ret = -EINVAL;
1019                 goto remove_static_opp;
1020         }
1021
1022         val = prop->value;
1023         while (nr) {
1024                 unsigned long freq = be32_to_cpup(val++) * 1000;
1025                 unsigned long volt = be32_to_cpup(val++);
1026
1027                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
1028                 if (ret) {
1029                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
1030                                 __func__, freq, ret);
1031                         goto remove_static_opp;
1032                 }
1033                 nr -= 2;
1034         }
1035
1036         return 0;
1037
1038 remove_static_opp:
1039         _opp_remove_all_static(opp_table);
1040
1041         return ret;
1042 }
1043
1044 static int _of_add_table_indexed(struct device *dev, int index, bool getclk)
1045 {
1046         struct opp_table *opp_table;
1047         int ret, count;
1048
1049         if (index) {
1050                 /*
1051                  * If only one phandle is present, then the same OPP table
1052                  * applies for all index requests.
1053                  */
1054                 count = of_count_phandle_with_args(dev->of_node,
1055                                                    "operating-points-v2", NULL);
1056                 if (count == 1)
1057                         index = 0;
1058         }
1059
1060         opp_table = _add_opp_table_indexed(dev, index, getclk);
1061         if (IS_ERR(opp_table))
1062                 return PTR_ERR(opp_table);
1063
1064         /*
1065          * OPPs have two version of bindings now. Also try the old (v1)
1066          * bindings for backward compatibility with older dtbs.
1067          */
1068         if (opp_table->np)
1069                 ret = _of_add_opp_table_v2(dev, opp_table);
1070         else
1071                 ret = _of_add_opp_table_v1(dev, opp_table);
1072
1073         if (ret)
1074                 dev_pm_opp_put_opp_table(opp_table);
1075
1076         return ret;
1077 }
1078
1079 static void devm_pm_opp_of_table_release(void *data)
1080 {
1081         dev_pm_opp_of_remove_table(data);
1082 }
1083
1084 /**
1085  * devm_pm_opp_of_add_table() - Initialize opp table from device tree
1086  * @dev:        device pointer used to lookup OPP table.
1087  *
1088  * Register the initial OPP table with the OPP library for given device.
1089  *
1090  * The opp_table structure will be freed after the device is destroyed.
1091  *
1092  * Return:
1093  * 0            On success OR
1094  *              Duplicate OPPs (both freq and volt are same) and opp->available
1095  * -EEXIST      Freq are same and volt are different OR
1096  *              Duplicate OPPs (both freq and volt are same) and !opp->available
1097  * -ENOMEM      Memory allocation failure
1098  * -ENODEV      when 'operating-points' property is not found or is invalid data
1099  *              in device node.
1100  * -ENODATA     when empty 'operating-points' property is found
1101  * -EINVAL      when invalid entries are found in opp-v2 table
1102  */
1103 int devm_pm_opp_of_add_table(struct device *dev)
1104 {
1105         int ret;
1106
1107         ret = dev_pm_opp_of_add_table(dev);
1108         if (ret)
1109                 return ret;
1110
1111         return devm_add_action_or_reset(dev, devm_pm_opp_of_table_release, dev);
1112 }
1113 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table);
1114
1115 /**
1116  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
1117  * @dev:        device pointer used to lookup OPP table.
1118  *
1119  * Register the initial OPP table with the OPP library for given device.
1120  *
1121  * Return:
1122  * 0            On success OR
1123  *              Duplicate OPPs (both freq and volt are same) and opp->available
1124  * -EEXIST      Freq are same and volt are different OR
1125  *              Duplicate OPPs (both freq and volt are same) and !opp->available
1126  * -ENOMEM      Memory allocation failure
1127  * -ENODEV      when 'operating-points' property is not found or is invalid data
1128  *              in device node.
1129  * -ENODATA     when empty 'operating-points' property is found
1130  * -EINVAL      when invalid entries are found in opp-v2 table
1131  */
1132 int dev_pm_opp_of_add_table(struct device *dev)
1133 {
1134         return _of_add_table_indexed(dev, 0, true);
1135 }
1136 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
1137
1138 /**
1139  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1140  * @dev:        device pointer used to lookup OPP table.
1141  * @index:      Index number.
1142  *
1143  * Register the initial OPP table with the OPP library for given device only
1144  * using the "operating-points-v2" property.
1145  *
1146  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1147  */
1148 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
1149 {
1150         return _of_add_table_indexed(dev, index, true);
1151 }
1152 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
1153
1154 /**
1155  * dev_pm_opp_of_add_table_noclk() - Initialize indexed opp table from device
1156  *              tree without getting clk for device.
1157  * @dev:        device pointer used to lookup OPP table.
1158  * @index:      Index number.
1159  *
1160  * Register the initial OPP table with the OPP library for given device only
1161  * using the "operating-points-v2" property. Do not try to get the clk for the
1162  * device.
1163  *
1164  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1165  */
1166 int dev_pm_opp_of_add_table_noclk(struct device *dev, int index)
1167 {
1168         return _of_add_table_indexed(dev, index, false);
1169 }
1170 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_noclk);
1171
1172 /* CPU device specific helpers */
1173
1174 /**
1175  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
1176  * @cpumask:    cpumask for which OPP table needs to be removed
1177  *
1178  * This removes the OPP tables for CPUs present in the @cpumask.
1179  * This should be used only to remove static entries created from DT.
1180  */
1181 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
1182 {
1183         _dev_pm_opp_cpumask_remove_table(cpumask, -1);
1184 }
1185 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
1186
1187 /**
1188  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
1189  * @cpumask:    cpumask for which OPP table needs to be added.
1190  *
1191  * This adds the OPP tables for CPUs present in the @cpumask.
1192  */
1193 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
1194 {
1195         struct device *cpu_dev;
1196         int cpu, ret;
1197
1198         if (WARN_ON(cpumask_empty(cpumask)))
1199                 return -ENODEV;
1200
1201         for_each_cpu(cpu, cpumask) {
1202                 cpu_dev = get_cpu_device(cpu);
1203                 if (!cpu_dev) {
1204                         pr_err("%s: failed to get cpu%d device\n", __func__,
1205                                cpu);
1206                         ret = -ENODEV;
1207                         goto remove_table;
1208                 }
1209
1210                 ret = dev_pm_opp_of_add_table(cpu_dev);
1211                 if (ret) {
1212                         /*
1213                          * OPP may get registered dynamically, don't print error
1214                          * message here.
1215                          */
1216                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
1217                                  __func__, cpu, ret);
1218
1219                         goto remove_table;
1220                 }
1221         }
1222
1223         return 0;
1224
1225 remove_table:
1226         /* Free all other OPPs */
1227         _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
1228
1229         return ret;
1230 }
1231 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
1232
1233 /*
1234  * Works only for OPP v2 bindings.
1235  *
1236  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
1237  */
1238 /**
1239  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
1240  *                                    @cpu_dev using operating-points-v2
1241  *                                    bindings.
1242  *
1243  * @cpu_dev:    CPU device for which we do this operation
1244  * @cpumask:    cpumask to update with information of sharing CPUs
1245  *
1246  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
1247  *
1248  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
1249  */
1250 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
1251                                    struct cpumask *cpumask)
1252 {
1253         struct device_node *np, *tmp_np, *cpu_np;
1254         int cpu, ret = 0;
1255
1256         /* Get OPP descriptor node */
1257         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
1258         if (!np) {
1259                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
1260                 return -ENOENT;
1261         }
1262
1263         cpumask_set_cpu(cpu_dev->id, cpumask);
1264
1265         /* OPPs are shared ? */
1266         if (!of_property_read_bool(np, "opp-shared"))
1267                 goto put_cpu_node;
1268
1269         for_each_possible_cpu(cpu) {
1270                 if (cpu == cpu_dev->id)
1271                         continue;
1272
1273                 cpu_np = of_cpu_device_node_get(cpu);
1274                 if (!cpu_np) {
1275                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
1276                                 __func__, cpu);
1277                         ret = -ENOENT;
1278                         goto put_cpu_node;
1279                 }
1280
1281                 /* Get OPP descriptor node */
1282                 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
1283                 of_node_put(cpu_np);
1284                 if (!tmp_np) {
1285                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
1286                         ret = -ENOENT;
1287                         goto put_cpu_node;
1288                 }
1289
1290                 /* CPUs are sharing opp node */
1291                 if (np == tmp_np)
1292                         cpumask_set_cpu(cpu, cpumask);
1293
1294                 of_node_put(tmp_np);
1295         }
1296
1297 put_cpu_node:
1298         of_node_put(np);
1299         return ret;
1300 }
1301 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
1302
1303 /**
1304  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
1305  * @np: Node that contains the "required-opps" property.
1306  * @index: Index of the phandle to parse.
1307  *
1308  * Returns the performance state of the OPP pointed out by the "required-opps"
1309  * property at @index in @np.
1310  *
1311  * Return: Zero or positive performance state on success, otherwise negative
1312  * value on errors.
1313  */
1314 int of_get_required_opp_performance_state(struct device_node *np, int index)
1315 {
1316         struct dev_pm_opp *opp;
1317         struct device_node *required_np;
1318         struct opp_table *opp_table;
1319         int pstate = -EINVAL;
1320
1321         required_np = of_parse_required_opp(np, index);
1322         if (!required_np)
1323                 return -ENODEV;
1324
1325         opp_table = _find_table_of_opp_np(required_np);
1326         if (IS_ERR(opp_table)) {
1327                 pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
1328                        __func__, np, PTR_ERR(opp_table));
1329                 goto put_required_np;
1330         }
1331
1332         opp = _find_opp_of_np(opp_table, required_np);
1333         if (opp) {
1334                 pstate = opp->pstate;
1335                 dev_pm_opp_put(opp);
1336         }
1337
1338         dev_pm_opp_put_opp_table(opp_table);
1339
1340 put_required_np:
1341         of_node_put(required_np);
1342
1343         return pstate;
1344 }
1345 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1346
1347 /**
1348  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1349  * @opp:        opp for which DT node has to be returned for
1350  *
1351  * Return: DT node corresponding to the opp, else 0 on success.
1352  *
1353  * The caller needs to put the node with of_node_put() after using it.
1354  */
1355 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1356 {
1357         if (IS_ERR_OR_NULL(opp)) {
1358                 pr_err("%s: Invalid parameters\n", __func__);
1359                 return NULL;
1360         }
1361
1362         return of_node_get(opp->np);
1363 }
1364 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1365
1366 /*
1367  * Callback function provided to the Energy Model framework upon registration.
1368  * This computes the power estimated by @dev at @kHz if it is the frequency
1369  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1370  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1371  * frequency and @mW to the associated power. The power is estimated as
1372  * P = C * V^2 * f with C being the device's capacitance and V and f
1373  * respectively the voltage and frequency of the OPP.
1374  *
1375  * Returns -EINVAL if the power calculation failed because of missing
1376  * parameters, 0 otherwise.
1377  */
1378 static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz,
1379                                      struct device *dev)
1380 {
1381         struct dev_pm_opp *opp;
1382         struct device_node *np;
1383         unsigned long mV, Hz;
1384         u32 cap;
1385         u64 tmp;
1386         int ret;
1387
1388         np = of_node_get(dev->of_node);
1389         if (!np)
1390                 return -EINVAL;
1391
1392         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1393         of_node_put(np);
1394         if (ret)
1395                 return -EINVAL;
1396
1397         Hz = *kHz * 1000;
1398         opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
1399         if (IS_ERR(opp))
1400                 return -EINVAL;
1401
1402         mV = dev_pm_opp_get_voltage(opp) / 1000;
1403         dev_pm_opp_put(opp);
1404         if (!mV)
1405                 return -EINVAL;
1406
1407         tmp = (u64)cap * mV * mV * (Hz / 1000000);
1408         do_div(tmp, 1000000000);
1409
1410         *mW = (unsigned long)tmp;
1411         *kHz = Hz / 1000;
1412
1413         return 0;
1414 }
1415
1416 /**
1417  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1418  * @dev         : Device for which an Energy Model has to be registered
1419  * @cpus        : CPUs for which an Energy Model has to be registered. For
1420  *              other type of devices it should be set to NULL.
1421  *
1422  * This checks whether the "dynamic-power-coefficient" devicetree property has
1423  * been specified, and tries to register an Energy Model with it if it has.
1424  * Having this property means the voltages are known for OPPs and the EM
1425  * might be calculated.
1426  */
1427 int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
1428 {
1429         struct em_data_callback em_cb = EM_DATA_CB(_get_power);
1430         struct device_node *np;
1431         int ret, nr_opp;
1432         u32 cap;
1433
1434         if (IS_ERR_OR_NULL(dev)) {
1435                 ret = -EINVAL;
1436                 goto failed;
1437         }
1438
1439         nr_opp = dev_pm_opp_get_opp_count(dev);
1440         if (nr_opp <= 0) {
1441                 ret = -EINVAL;
1442                 goto failed;
1443         }
1444
1445         np = of_node_get(dev->of_node);
1446         if (!np) {
1447                 ret = -EINVAL;
1448                 goto failed;
1449         }
1450
1451         /*
1452          * Register an EM only if the 'dynamic-power-coefficient' property is
1453          * set in devicetree. It is assumed the voltage values are known if that
1454          * property is set since it is useless otherwise. If voltages are not
1455          * known, just let the EM registration fail with an error to alert the
1456          * user about the inconsistent configuration.
1457          */
1458         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1459         of_node_put(np);
1460         if (ret || !cap) {
1461                 dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
1462                 ret = -EINVAL;
1463                 goto failed;
1464         }
1465
1466         ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
1467         if (ret)
1468                 goto failed;
1469
1470         return 0;
1471
1472 failed:
1473         dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
1474         return ret;
1475 }
1476 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);