drivers/opp/of.c

   1 /*
   2  * Generic OPP OF helpers
   3  *
   4  * Copyright (C) 2009-2010 Texas Instruments Incorporated.
   5  *      Nishanth Menon
   6  *      Romit Dasgupta
   7  *      Kevin Hilman
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/cpu.h>
  17 #include <linux/errno.h>
  18 #include <linux/device.h>
  19 #include <linux/of_device.h>
  20 #include <linux/pm_domain.h>
  21 #include <linux/slab.h>
  22 #include <linux/export.h>
  23
  24 #include "opp.h"
  25
  26 /*
  27  * Returns opp descriptor node for a device node, caller must
  28  * do of_node_put().
  29  */
  30 static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np,
  31                                                      int index)
  32 {
  33         /* "operating-points-v2" can be an array for power domain providers */
  34         return of_parse_phandle(np, "operating-points-v2", index);
  35 }
  36
  37 /* Returns opp descriptor node for a device, caller must do of_node_put() */
  38 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
  39 {
  40         return _opp_of_get_opp_desc_node(dev->of_node, 0);
  41 }
  42 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
  43
  44 static struct opp_table *_managed_opp(const struct device_node *np)
  45 {
  46         struct opp_table *opp_table, *managed_table = NULL;
  47
  48         mutex_lock(&opp_table_lock);
  49
  50         list_for_each_entry(opp_table, &opp_tables, node) {
  51                 if (opp_table->np == np) {
  52                         /*
  53                          * Multiple devices can point to the same OPP table and
  54                          * so will have same node-pointer, np.
  55                          *
  56                          * But the OPPs will be considered as shared only if the
  57                          * OPP table contains a "opp-shared" property.
  58                          */
  59                         if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
  60                                 _get_opp_table_kref(opp_table);
  61                                 managed_table = opp_table;
  62                         }
  63
  64                         break;
  65                 }
  66         }
  67
  68         mutex_unlock(&opp_table_lock);
  69
  70         return managed_table;
  71 }
  72
  73 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
  74                         int index)
  75 {
  76         struct device_node *np, *opp_np;
  77         u32 val;
  78
  79         /*
  80          * Only required for backward compatibility with v1 bindings, but isn't
  81          * harmful for other cases. And so we do it unconditionally.
  82          */
  83         np = of_node_get(dev->of_node);
  84         if (!np)
  85                 return;
  86
  87         if (!of_property_read_u32(np, "clock-latency", &val))
  88                 opp_table->clock_latency_ns_max = val;
  89         of_property_read_u32(np, "voltage-tolerance",
  90                              &opp_table->voltage_tolerance_v1);
  91
  92         /* Get OPP table node */
  93         opp_np = _opp_of_get_opp_desc_node(np, index);
  94         of_node_put(np);
  95
  96         if (!opp_np)
  97                 return;
  98
  99         if (of_property_read_bool(opp_np, "opp-shared"))
 100                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
 101         else
 102                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
 103
 104         opp_table->np = opp_np;
 105
 106         of_node_put(opp_np);
 107 }
 108
 109 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
 110                               struct device_node *np)
 111 {
 112         unsigned int count = opp_table->supported_hw_count;
 113         u32 version;
 114         int ret;
 115
 116         if (!opp_table->supported_hw) {
 117                 /*
 118                  * In the case that no supported_hw has been set by the
 119                  * platform but there is an opp-supported-hw value set for
 120                  * an OPP then the OPP should not be enabled as there is
 121                  * no way to see if the hardware supports it.
 122                  */
 123                 if (of_find_property(np, "opp-supported-hw", NULL))
 124                         return false;
 125                 else
 126                         return true;
 127         }
 128
 129         while (count--) {
 130                 ret = of_property_read_u32_index(np, "opp-supported-hw", count,
 131                                                  &version);
 132                 if (ret) {
 133                         dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
 134                                  __func__, count, ret);
 135                         return false;
 136                 }
 137
 138                 /* Both of these are bitwise masks of the versions */
 139                 if (!(version & opp_table->supported_hw[count]))
 140                         return false;
 141         }
 142
 143         return true;
 144 }
 145
 146 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 147                               struct opp_table *opp_table)
 148 {
 149         u32 *microvolt, *microamp = NULL;
 150         int supplies, vcount, icount, ret, i, j;
 151         struct property *prop = NULL;
 152         char name[NAME_MAX];
 153
 154         supplies = opp_table->regulator_count ? opp_table->regulator_count : 1;
 155
 156         /* Search for "opp-microvolt-<name>" */
 157         if (opp_table->prop_name) {
 158                 snprintf(name, sizeof(name), "opp-microvolt-%s",
 159                          opp_table->prop_name);
 160                 prop = of_find_property(opp->np, name, NULL);
 161         }
 162
 163         if (!prop) {
 164                 /* Search for "opp-microvolt" */
 165                 sprintf(name, "opp-microvolt");
 166                 prop = of_find_property(opp->np, name, NULL);
 167
 168                 /* Missing property isn't a problem, but an invalid entry is */
 169                 if (!prop) {
 170                         if (!opp_table->regulator_count)
 171                                 return 0;
 172
 173                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
 174                                 __func__);
 175                         return -EINVAL;
 176                 }
 177         }
 178
 179         vcount = of_property_count_u32_elems(opp->np, name);
 180         if (vcount < 0) {
 181                 dev_err(dev, "%s: Invalid %s property (%d)\n",
 182                         __func__, name, vcount);
 183                 return vcount;
 184         }
 185
 186         /* There can be one or three elements per supply */
 187         if (vcount != supplies && vcount != supplies * 3) {
 188                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 189                         __func__, name, vcount, supplies);
 190                 return -EINVAL;
 191         }
 192
 193         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
 194         if (!microvolt)
 195                 return -ENOMEM;
 196
 197         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
 198         if (ret) {
 199                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 200                 ret = -EINVAL;
 201                 goto free_microvolt;
 202         }
 203
 204         /* Search for "opp-microamp-<name>" */
 205         prop = NULL;
 206         if (opp_table->prop_name) {
 207                 snprintf(name, sizeof(name), "opp-microamp-%s",
 208                          opp_table->prop_name);
 209                 prop = of_find_property(opp->np, name, NULL);
 210         }
 211
 212         if (!prop) {
 213                 /* Search for "opp-microamp" */
 214                 sprintf(name, "opp-microamp");
 215                 prop = of_find_property(opp->np, name, NULL);
 216         }
 217
 218         if (prop) {
 219                 icount = of_property_count_u32_elems(opp->np, name);
 220                 if (icount < 0) {
 221                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 222                                 name, icount);
 223                         ret = icount;
 224                         goto free_microvolt;
 225                 }
 226
 227                 if (icount != supplies) {
 228                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 229                                 __func__, name, icount, supplies);
 230                         ret = -EINVAL;
 231                         goto free_microvolt;
 232                 }
 233
 234                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
 235                 if (!microamp) {
 236                         ret = -EINVAL;
 237                         goto free_microvolt;
 238                 }
 239
 240                 ret = of_property_read_u32_array(opp->np, name, microamp,
 241                                                  icount);
 242                 if (ret) {
 243                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 244                                 name, ret);
 245                         ret = -EINVAL;
 246                         goto free_microamp;
 247                 }
 248         }
 249
 250         for (i = 0, j = 0; i < supplies; i++) {
 251                 opp->supplies[i].u_volt = microvolt[j++];
 252
 253                 if (vcount == supplies) {
 254                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
 255                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
 256                 } else {
 257                         opp->supplies[i].u_volt_min = microvolt[j++];
 258                         opp->supplies[i].u_volt_max = microvolt[j++];
 259                 }
 260
 261                 if (microamp)
 262                         opp->supplies[i].u_amp = microamp[i];
 263         }
 264
 265 free_microamp:
 266         kfree(microamp);
 267 free_microvolt:
 268         kfree(microvolt);
 269
 270         return ret;
 271 }
 272
 273 /**
 274  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 275  *                                entries
 276  * @dev:        device pointer used to lookup OPP table.
 277  *
 278  * Free OPPs created using static entries present in DT.
 279  */
 280 void dev_pm_opp_of_remove_table(struct device *dev)
 281 {
 282         _dev_pm_opp_find_and_remove_table(dev);
 283 }
 284 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 285
 286 /**
 287  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 288  * @opp_table:  OPP table
 289  * @dev:        device for which we do this operation
 290  * @np:         device node
 291  *
 292  * This function adds an opp definition to the opp table and returns status. The
 293  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 294  * removed by dev_pm_opp_remove.
 295  *
 296  * Return:
 297  * 0            On success OR
 298  *              Duplicate OPPs (both freq and volt are same) and opp->available
 299  * -EEXIST      Freq are same and volt are different OR
 300  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 301  * -ENOMEM      Memory allocation failure
 302  * -EINVAL      Failed parsing the OPP node
 303  */
 304 static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev,
 305                               struct device_node *np)
 306 {
 307         struct dev_pm_opp *new_opp;
 308         u64 rate = 0;
 309         u32 val;
 310         int ret;
 311         bool rate_not_available = false;
 312
 313         new_opp = _opp_allocate(opp_table);
 314         if (!new_opp)
 315                 return -ENOMEM;
 316
 317         ret = of_property_read_u64(np, "opp-hz", &rate);
 318         if (ret < 0) {
 319                 /* "opp-hz" is optional for devices like power domains. */
 320                 if (!of_find_property(dev->of_node, "#power-domain-cells",
 321                                       NULL)) {
 322                         dev_err(dev, "%s: opp-hz not found\n", __func__);
 323                         goto free_opp;
 324                 }
 325
 326                 rate_not_available = true;
 327         } else {
 328                 /*
 329                  * Rate is defined as an unsigned long in clk API, and so
 330                  * casting explicitly to its type. Must be fixed once rate is 64
 331                  * bit guaranteed in clk API.
 332                  */
 333                 new_opp->rate = (unsigned long)rate;
 334         }
 335
 336         /* Check if the OPP supports hardware's hierarchy of versions or not */
 337         if (!_opp_is_supported(dev, opp_table, np)) {
 338                 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
 339                 goto free_opp;
 340         }
 341
 342         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 343
 344         new_opp->np = np;
 345         new_opp->dynamic = false;
 346         new_opp->available = true;
 347
 348         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 349                 new_opp->clock_latency_ns = val;
 350
 351         new_opp->pstate = of_genpd_opp_to_performance_state(dev, np);
 352
 353         ret = opp_parse_supplies(new_opp, dev, opp_table);
 354         if (ret)
 355                 goto free_opp;
 356
 357         ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
 358         if (ret) {
 359                 /* Don't return error for duplicate OPPs */
 360                 if (ret == -EBUSY)
 361                         ret = 0;
 362                 goto free_opp;
 363         }
 364
 365         /* OPP to select on device suspend */
 366         if (of_property_read_bool(np, "opp-suspend")) {
 367                 if (opp_table->suspend_opp) {
 368                         dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
 369                                  __func__, opp_table->suspend_opp->rate,
 370                                  new_opp->rate);
 371                 } else {
 372                         new_opp->suspend = true;
 373                         opp_table->suspend_opp = new_opp;
 374                 }
 375         }
 376
 377         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 378                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 379
 380         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
 381                  __func__, new_opp->turbo, new_opp->rate,
 382                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 383                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
 384
 385         /*
 386          * Notify the changes in the availability of the operable
 387          * frequency/voltage list.
 388          */
 389         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
 390         return 0;
 391
 392 free_opp:
 393         _opp_free(new_opp);
 394
 395         return ret;
 396 }
 397
 398 /* Initializes OPP tables based on new bindings */
 399 static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np,
 400                                 int index)
 401 {
 402         struct device_node *np;
 403         struct opp_table *opp_table;
 404         int ret = 0, count = 0, pstate_count = 0;
 405         struct dev_pm_opp *opp;
 406
 407         opp_table = _managed_opp(opp_np);
 408         if (opp_table) {
 409                 /* OPPs are already managed */
 410                 if (!_add_opp_dev(dev, opp_table))
 411                         ret = -ENOMEM;
 412                 else if (!opp_table->parsed_static_opps)
 413                         goto initialize_static_opps;
 414                 else
 415                         kref_get(&opp_table->list_kref);
 416
 417                 goto put_opp_table;
 418         }
 419
 420         opp_table = dev_pm_opp_get_opp_table_indexed(dev, index);
 421         if (!opp_table)
 422                 return -ENOMEM;
 423
 424 initialize_static_opps:
 425         kref_init(&opp_table->list_kref);
 426
 427         /* We have opp-table node now, iterate over it and add OPPs */
 428         for_each_available_child_of_node(opp_np, np) {
 429                 count++;
 430
 431                 ret = _opp_add_static_v2(opp_table, dev, np);
 432                 if (ret) {
 433                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 434                                 ret);
 435                         _dev_pm_opp_remove_table(opp_table, dev);
 436                         of_node_put(np);
 437                         goto put_opp_table;
 438                 }
 439         }
 440
 441         /* There should be one of more OPP defined */
 442         if (WARN_ON(!count)) {
 443                 ret = -ENOENT;
 444                 _put_opp_list_kref(opp_table);
 445                 goto put_opp_table;
 446         }
 447
 448         list_for_each_entry(opp, &opp_table->opp_list, node)
 449                 pstate_count += !!opp->pstate;
 450
 451         /* Either all or none of the nodes shall have performance state set */
 452         if (pstate_count && pstate_count != count) {
 453                 dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
 454                         count, pstate_count);
 455                 ret = -ENOENT;
 456                 _dev_pm_opp_remove_table(opp_table, dev);
 457                 goto put_opp_table;
 458         }
 459
 460         if (pstate_count)
 461                 opp_table->genpd_performance_state = true;
 462
 463         opp_table->parsed_static_opps = true;
 464
 465 put_opp_table:
 466         dev_pm_opp_put_opp_table(opp_table);
 467
 468         return ret;
 469 }
 470
 471 /* Initializes OPP tables based on old-deprecated bindings */
 472 static int _of_add_opp_table_v1(struct device *dev)
 473 {
 474         struct opp_table *opp_table;
 475         const struct property *prop;
 476         const __be32 *val;
 477         int nr, ret = 0;
 478
 479         prop = of_find_property(dev->of_node, "operating-points", NULL);
 480         if (!prop)
 481                 return -ENODEV;
 482         if (!prop->value)
 483                 return -ENODATA;
 484
 485         /*
 486          * Each OPP is a set of tuples consisting of frequency and
 487          * voltage like <freq-kHz vol-uV>.
 488          */
 489         nr = prop->length / sizeof(u32);
 490         if (nr % 2) {
 491                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
 492                 return -EINVAL;
 493         }
 494
 495         opp_table = dev_pm_opp_get_opp_table(dev);
 496         if (!opp_table)
 497                 return -ENOMEM;
 498
 499         kref_init(&opp_table->list_kref);
 500
 501         val = prop->value;
 502         while (nr) {
 503                 unsigned long freq = be32_to_cpup(val++) * 1000;
 504                 unsigned long volt = be32_to_cpup(val++);
 505
 506                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
 507                 if (ret) {
 508                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
 509                                 __func__, freq, ret);
 510                         _dev_pm_opp_remove_table(opp_table, dev);
 511                         break;
 512                 }
 513                 nr -= 2;
 514         }
 515
 516         dev_pm_opp_put_opp_table(opp_table);
 517         return ret;
 518 }
 519
 520 /**
 521  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
 522  * @dev:        device pointer used to lookup OPP table.
 523  *
 524  * Register the initial OPP table with the OPP library for given device.
 525  *
 526  * Return:
 527  * 0            On success OR
 528  *              Duplicate OPPs (both freq and volt are same) and opp->available
 529  * -EEXIST      Freq are same and volt are different OR
 530  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 531  * -ENOMEM      Memory allocation failure
 532  * -ENODEV      when 'operating-points' property is not found or is invalid data
 533  *              in device node.
 534  * -ENODATA     when empty 'operating-points' property is found
 535  * -EINVAL      when invalid entries are found in opp-v2 table
 536  */
 537 int dev_pm_opp_of_add_table(struct device *dev)
 538 {
 539         struct device_node *opp_np;
 540         int ret;
 541
 542         /*
 543          * OPPs have two version of bindings now. The older one is deprecated,
 544          * try for the new binding first.
 545          */
 546         opp_np = dev_pm_opp_of_get_opp_desc_node(dev);
 547         if (!opp_np) {
 548                 /*
 549                  * Try old-deprecated bindings for backward compatibility with
 550                  * older dtbs.
 551                  */
 552                 return _of_add_opp_table_v1(dev);
 553         }
 554
 555         ret = _of_add_opp_table_v2(dev, opp_np, 0);
 556         of_node_put(opp_np);
 557
 558         return ret;
 559 }
 560 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
 561
 562 /**
 563  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
 564  * @dev:        device pointer used to lookup OPP table.
 565  * @index:      Index number.
 566  *
 567  * Register the initial OPP table with the OPP library for given device only
 568  * using the "operating-points-v2" property.
 569  *
 570  * Return:
 571  * 0            On success OR
 572  *              Duplicate OPPs (both freq and volt are same) and opp->available
 573  * -EEXIST      Freq are same and volt are different OR
 574  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 575  * -ENOMEM      Memory allocation failure
 576  * -ENODEV      when 'operating-points' property is not found or is invalid data
 577  *              in device node.
 578  * -ENODATA     when empty 'operating-points' property is found
 579  * -EINVAL      when invalid entries are found in opp-v2 table
 580  */
 581 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
 582 {
 583         struct device_node *opp_np;
 584         int ret, count;
 585
 586 again:
 587         opp_np = _opp_of_get_opp_desc_node(dev->of_node, index);
 588         if (!opp_np) {
 589                 /*
 590                  * If only one phandle is present, then the same OPP table
 591                  * applies for all index requests.
 592                  */
 593                 count = of_count_phandle_with_args(dev->of_node,
 594                                                    "operating-points-v2", NULL);
 595                 if (count == 1 && index) {
 596                         index = 0;
 597                         goto again;
 598                 }
 599
 600                 return -ENODEV;
 601         }
 602
 603         ret = _of_add_opp_table_v2(dev, opp_np, index);
 604         of_node_put(opp_np);
 605
 606         return ret;
 607 }
 608 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
 609
 610 /* CPU device specific helpers */
 611
 612 /**
 613  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
 614  * @cpumask:    cpumask for which OPP table needs to be removed
 615  *
 616  * This removes the OPP tables for CPUs present in the @cpumask.
 617  * This should be used only to remove static entries created from DT.
 618  */
 619 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
 620 {
 621         _dev_pm_opp_cpumask_remove_table(cpumask, -1);
 622 }
 623 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
 624
 625 /**
 626  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
 627  * @cpumask:    cpumask for which OPP table needs to be added.
 628  *
 629  * This adds the OPP tables for CPUs present in the @cpumask.
 630  */
 631 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
 632 {
 633         struct device *cpu_dev;
 634         int cpu, ret = 0;
 635
 636         WARN_ON(cpumask_empty(cpumask));
 637
 638         for_each_cpu(cpu, cpumask) {
 639                 cpu_dev = get_cpu_device(cpu);
 640                 if (!cpu_dev) {
 641                         pr_err("%s: failed to get cpu%d device\n", __func__,
 642                                cpu);
 643                         continue;
 644                 }
 645
 646                 ret = dev_pm_opp_of_add_table(cpu_dev);
 647                 if (ret) {
 648                         /*
 649                          * OPP may get registered dynamically, don't print error
 650                          * message here.
 651                          */
 652                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
 653                                  __func__, cpu, ret);
 654
 655                         /* Free all other OPPs */
 656                         _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
 657                         break;
 658                 }
 659         }
 660
 661         return ret;
 662 }
 663 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
 664
 665 /*
 666  * Works only for OPP v2 bindings.
 667  *
 668  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
 669  */
 670 /**
 671  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
 672  *                                    @cpu_dev using operating-points-v2
 673  *                                    bindings.
 674  *
 675  * @cpu_dev:    CPU device for which we do this operation
 676  * @cpumask:    cpumask to update with information of sharing CPUs
 677  *
 678  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 679  *
 680  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
 681  */
 682 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
 683                                    struct cpumask *cpumask)
 684 {
 685         struct device_node *np, *tmp_np, *cpu_np;
 686         int cpu, ret = 0;
 687
 688         /* Get OPP descriptor node */
 689         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
 690         if (!np) {
 691                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
 692                 return -ENOENT;
 693         }
 694
 695         cpumask_set_cpu(cpu_dev->id, cpumask);
 696
 697         /* OPPs are shared ? */
 698         if (!of_property_read_bool(np, "opp-shared"))
 699                 goto put_cpu_node;
 700
 701         for_each_possible_cpu(cpu) {
 702                 if (cpu == cpu_dev->id)
 703                         continue;
 704
 705                 cpu_np = of_cpu_device_node_get(cpu);
 706                 if (!cpu_np) {
 707                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
 708                                 __func__, cpu);
 709                         ret = -ENOENT;
 710                         goto put_cpu_node;
 711                 }
 712
 713                 /* Get OPP descriptor node */
 714                 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
 715                 of_node_put(cpu_np);
 716                 if (!tmp_np) {
 717                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
 718                         ret = -ENOENT;
 719                         goto put_cpu_node;
 720                 }
 721
 722                 /* CPUs are sharing opp node */
 723                 if (np == tmp_np)
 724                         cpumask_set_cpu(cpu, cpumask);
 725
 726                 of_node_put(tmp_np);
 727         }
 728
 729 put_cpu_node:
 730         of_node_put(np);
 731         return ret;
 732 }
 733 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
 734
 735 /**
 736  * of_dev_pm_opp_find_required_opp() - Search for required OPP.
 737  * @dev: The device whose OPP node is referenced by the 'np' DT node.
 738  * @np: Node that contains the "required-opps" property.
 739  *
 740  * Returns the OPP of the device 'dev', whose phandle is present in the "np"
 741  * node. Although the "required-opps" property supports having multiple
 742  * phandles, this helper routine only parses the very first phandle in the list.
 743  *
 744  * Return: Matching opp, else returns ERR_PTR in case of error and should be
 745  * handled using IS_ERR.
 746  *
 747  * The callers are required to call dev_pm_opp_put() for the returned OPP after
 748  * use.
 749  */
 750 struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev,
 751                                                    struct device_node *np)
 752 {
 753         struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ENODEV);
 754         struct device_node *required_np;
 755         struct opp_table *opp_table;
 756
 757         opp_table = _find_opp_table(dev);
 758         if (IS_ERR(opp_table))
 759                 return ERR_CAST(opp_table);
 760
 761         required_np = of_parse_phandle(np, "required-opps", 0);
 762         if (unlikely(!required_np)) {
 763                 dev_err(dev, "Unable to parse required-opps\n");
 764                 goto put_opp_table;
 765         }
 766
 767         mutex_lock(&opp_table->lock);
 768
 769         list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
 770                 if (temp_opp->available && temp_opp->np == required_np) {
 771                         opp = temp_opp;
 772
 773                         /* Increment the reference count of OPP */
 774                         dev_pm_opp_get(opp);
 775                         break;
 776                 }
 777         }
 778
 779         mutex_unlock(&opp_table->lock);
 780
 781         of_node_put(required_np);
 782 put_opp_table:
 783         dev_pm_opp_put_opp_table(opp_table);
 784
 785         return opp;
 786 }
 787 EXPORT_SYMBOL_GPL(of_dev_pm_opp_find_required_opp);
 788
 789 /**
 790  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
 791  * @opp:        opp for which DT node has to be returned for
 792  *
 793  * Return: DT node corresponding to the opp, else 0 on success.
 794  *
 795  * The caller needs to put the node with of_node_put() after using it.
 796  */
 797 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
 798 {
 799         if (IS_ERR_OR_NULL(opp)) {
 800                 pr_err("%s: Invalid parameters\n", __func__);
 801                 return NULL;
 802         }
 803
 804         return of_node_get(opp->np);
 805 }
 806 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);