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 struct opp_table *_managed_opp(struct device *dev, int index)
  45 {
  46         struct opp_table *opp_table, *managed_table = NULL;
  47         struct device_node *np;
  48
  49         np = _opp_of_get_opp_desc_node(dev->of_node, index);
  50         if (!np)
  51                 return NULL;
  52
  53         list_for_each_entry(opp_table, &opp_tables, node) {
  54                 if (opp_table->np == np) {
  55                         /*
  56                          * Multiple devices can point to the same OPP table and
  57                          * so will have same node-pointer, np.
  58                          *
  59                          * But the OPPs will be considered as shared only if the
  60                          * OPP table contains a "opp-shared" property.
  61                          */
  62                         if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
  63                                 _get_opp_table_kref(opp_table);
  64                                 managed_table = opp_table;
  65                         }
  66
  67                         break;
  68                 }
  69         }
  70
  71         of_node_put(np);
  72
  73         return managed_table;
  74 }
  75
  76 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
  77                         int index)
  78 {
  79         struct device_node *np, *opp_np;
  80         u32 val;
  81
  82         /*
  83          * Only required for backward compatibility with v1 bindings, but isn't
  84          * harmful for other cases. And so we do it unconditionally.
  85          */
  86         np = of_node_get(dev->of_node);
  87         if (!np)
  88                 return;
  89
  90         if (!of_property_read_u32(np, "clock-latency", &val))
  91                 opp_table->clock_latency_ns_max = val;
  92         of_property_read_u32(np, "voltage-tolerance",
  93                              &opp_table->voltage_tolerance_v1);
  94
  95         /* Get OPP table node */
  96         opp_np = _opp_of_get_opp_desc_node(np, index);
  97         of_node_put(np);
  98
  99         if (!opp_np)
 100                 return;
 101
 102         if (of_property_read_bool(opp_np, "opp-shared"))
 103                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
 104         else
 105                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
 106
 107         opp_table->np = opp_np;
 108
 109         of_node_put(opp_np);
 110 }
 111
 112 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
 113                               struct device_node *np)
 114 {
 115         unsigned int count = opp_table->supported_hw_count;
 116         u32 version;
 117         int ret;
 118
 119         if (!opp_table->supported_hw) {
 120                 /*
 121                  * In the case that no supported_hw has been set by the
 122                  * platform but there is an opp-supported-hw value set for
 123                  * an OPP then the OPP should not be enabled as there is
 124                  * no way to see if the hardware supports it.
 125                  */
 126                 if (of_find_property(np, "opp-supported-hw", NULL))
 127                         return false;
 128                 else
 129                         return true;
 130         }
 131
 132         while (count--) {
 133                 ret = of_property_read_u32_index(np, "opp-supported-hw", count,
 134                                                  &version);
 135                 if (ret) {
 136                         dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
 137                                  __func__, count, ret);
 138                         return false;
 139                 }
 140
 141                 /* Both of these are bitwise masks of the versions */
 142                 if (!(version & opp_table->supported_hw[count]))
 143                         return false;
 144         }
 145
 146         return true;
 147 }
 148
 149 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 150                               struct opp_table *opp_table)
 151 {
 152         u32 *microvolt, *microamp = NULL;
 153         int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
 154         struct property *prop = NULL;
 155         char name[NAME_MAX];
 156
 157         /* Search for "opp-microvolt-<name>" */
 158         if (opp_table->prop_name) {
 159                 snprintf(name, sizeof(name), "opp-microvolt-%s",
 160                          opp_table->prop_name);
 161                 prop = of_find_property(opp->np, name, NULL);
 162         }
 163
 164         if (!prop) {
 165                 /* Search for "opp-microvolt" */
 166                 sprintf(name, "opp-microvolt");
 167                 prop = of_find_property(opp->np, name, NULL);
 168
 169                 /* Missing property isn't a problem, but an invalid entry is */
 170                 if (!prop) {
 171                         if (unlikely(supplies == -1)) {
 172                                 /* Initialize regulator_count */
 173                                 opp_table->regulator_count = 0;
 174                                 return 0;
 175                         }
 176
 177                         if (!supplies)
 178                                 return 0;
 179
 180                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
 181                                 __func__);
 182                         return -EINVAL;
 183                 }
 184         }
 185
 186         if (unlikely(supplies == -1)) {
 187                 /* Initialize regulator_count */
 188                 supplies = opp_table->regulator_count = 1;
 189         } else if (unlikely(!supplies)) {
 190                 dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
 191                 return -EINVAL;
 192         }
 193
 194         vcount = of_property_count_u32_elems(opp->np, name);
 195         if (vcount < 0) {
 196                 dev_err(dev, "%s: Invalid %s property (%d)\n",
 197                         __func__, name, vcount);
 198                 return vcount;
 199         }
 200
 201         /* There can be one or three elements per supply */
 202         if (vcount != supplies && vcount != supplies * 3) {
 203                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 204                         __func__, name, vcount, supplies);
 205                 return -EINVAL;
 206         }
 207
 208         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
 209         if (!microvolt)
 210                 return -ENOMEM;
 211
 212         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
 213         if (ret) {
 214                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 215                 ret = -EINVAL;
 216                 goto free_microvolt;
 217         }
 218
 219         /* Search for "opp-microamp-<name>" */
 220         prop = NULL;
 221         if (opp_table->prop_name) {
 222                 snprintf(name, sizeof(name), "opp-microamp-%s",
 223                          opp_table->prop_name);
 224                 prop = of_find_property(opp->np, name, NULL);
 225         }
 226
 227         if (!prop) {
 228                 /* Search for "opp-microamp" */
 229                 sprintf(name, "opp-microamp");
 230                 prop = of_find_property(opp->np, name, NULL);
 231         }
 232
 233         if (prop) {
 234                 icount = of_property_count_u32_elems(opp->np, name);
 235                 if (icount < 0) {
 236                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 237                                 name, icount);
 238                         ret = icount;
 239                         goto free_microvolt;
 240                 }
 241
 242                 if (icount != supplies) {
 243                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 244                                 __func__, name, icount, supplies);
 245                         ret = -EINVAL;
 246                         goto free_microvolt;
 247                 }
 248
 249                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
 250                 if (!microamp) {
 251                         ret = -EINVAL;
 252                         goto free_microvolt;
 253                 }
 254
 255                 ret = of_property_read_u32_array(opp->np, name, microamp,
 256                                                  icount);
 257                 if (ret) {
 258                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 259                                 name, ret);
 260                         ret = -EINVAL;
 261                         goto free_microamp;
 262                 }
 263         }
 264
 265         for (i = 0, j = 0; i < supplies; i++) {
 266                 opp->supplies[i].u_volt = microvolt[j++];
 267
 268                 if (vcount == supplies) {
 269                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
 270                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
 271                 } else {
 272                         opp->supplies[i].u_volt_min = microvolt[j++];
 273                         opp->supplies[i].u_volt_max = microvolt[j++];
 274                 }
 275
 276                 if (microamp)
 277                         opp->supplies[i].u_amp = microamp[i];
 278         }
 279
 280 free_microamp:
 281         kfree(microamp);
 282 free_microvolt:
 283         kfree(microvolt);
 284
 285         return ret;
 286 }
 287
 288 /**
 289  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 290  *                                entries
 291  * @dev:        device pointer used to lookup OPP table.
 292  *
 293  * Free OPPs created using static entries present in DT.
 294  */
 295 void dev_pm_opp_of_remove_table(struct device *dev)
 296 {
 297         _dev_pm_opp_find_and_remove_table(dev);
 298 }
 299 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 300
 301 /**
 302  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 303  * @opp_table:  OPP table
 304  * @dev:        device for which we do this operation
 305  * @np:         device node
 306  *
 307  * This function adds an opp definition to the opp table and returns status. The
 308  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 309  * removed by dev_pm_opp_remove.
 310  *
 311  * Return:
 312  * Valid OPP pointer:
 313  *              On success
 314  * NULL:
 315  *              Duplicate OPPs (both freq and volt are same) and opp->available
 316  *              OR if the OPP is not supported by hardware.
 317  * ERR_PTR(-EEXIST):
 318  *              Freq are same and volt are different OR
 319  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 320  * ERR_PTR(-ENOMEM):
 321  *              Memory allocation failure
 322  * ERR_PTR(-EINVAL):
 323  *              Failed parsing the OPP node
 324  */
 325 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 326                 struct device *dev, struct device_node *np)
 327 {
 328         struct dev_pm_opp *new_opp;
 329         u64 rate = 0;
 330         u32 val;
 331         int ret;
 332         bool rate_not_available = false;
 333
 334         new_opp = _opp_allocate(opp_table);
 335         if (!new_opp)
 336                 return ERR_PTR(-ENOMEM);
 337
 338         ret = of_property_read_u64(np, "opp-hz", &rate);
 339         if (ret < 0) {
 340                 /* "opp-hz" is optional for devices like power domains. */
 341                 if (!of_find_property(dev->of_node, "#power-domain-cells",
 342                                       NULL)) {
 343                         dev_err(dev, "%s: opp-hz not found\n", __func__);
 344                         goto free_opp;
 345                 }
 346
 347                 rate_not_available = true;
 348         } else {
 349                 /*
 350                  * Rate is defined as an unsigned long in clk API, and so
 351                  * casting explicitly to its type. Must be fixed once rate is 64
 352                  * bit guaranteed in clk API.
 353                  */
 354                 new_opp->rate = (unsigned long)rate;
 355         }
 356
 357         /* Check if the OPP supports hardware's hierarchy of versions or not */
 358         if (!_opp_is_supported(dev, opp_table, np)) {
 359                 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
 360                 goto free_opp;
 361         }
 362
 363         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 364
 365         new_opp->np = np;
 366         new_opp->dynamic = false;
 367         new_opp->available = true;
 368
 369         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 370                 new_opp->clock_latency_ns = val;
 371
 372         new_opp->pstate = of_genpd_opp_to_performance_state(dev, np);
 373
 374         ret = opp_parse_supplies(new_opp, dev, opp_table);
 375         if (ret)
 376                 goto free_opp;
 377
 378         ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
 379         if (ret) {
 380                 /* Don't return error for duplicate OPPs */
 381                 if (ret == -EBUSY)
 382                         ret = 0;
 383                 goto free_opp;
 384         }
 385
 386         /* OPP to select on device suspend */
 387         if (of_property_read_bool(np, "opp-suspend")) {
 388                 if (opp_table->suspend_opp) {
 389                         dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
 390                                  __func__, opp_table->suspend_opp->rate,
 391                                  new_opp->rate);
 392                 } else {
 393                         new_opp->suspend = true;
 394                         opp_table->suspend_opp = new_opp;
 395                 }
 396         }
 397
 398         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 399                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 400
 401         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
 402                  __func__, new_opp->turbo, new_opp->rate,
 403                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 404                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
 405
 406         /*
 407          * Notify the changes in the availability of the operable
 408          * frequency/voltage list.
 409          */
 410         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
 411         return new_opp;
 412
 413 free_opp:
 414         _opp_free(new_opp);
 415
 416         return ERR_PTR(ret);
 417 }
 418
 419 /* Initializes OPP tables based on new bindings */
 420 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 421 {
 422         struct device_node *np;
 423         int ret, count = 0, pstate_count = 0;
 424         struct dev_pm_opp *opp;
 425
 426         /* OPP table is already initialized for the device */
 427         if (opp_table->parsed_static_opps) {
 428                 kref_get(&opp_table->list_kref);
 429                 return 0;
 430         }
 431
 432         kref_init(&opp_table->list_kref);
 433
 434         /* We have opp-table node now, iterate over it and add OPPs */
 435         for_each_available_child_of_node(opp_table->np, np) {
 436                 opp = _opp_add_static_v2(opp_table, dev, np);
 437                 if (IS_ERR(opp)) {
 438                         ret = PTR_ERR(opp);
 439                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 440                                 ret);
 441                         of_node_put(np);
 442                         goto put_list_kref;
 443                 } else if (opp) {
 444                         count++;
 445                 }
 446         }
 447
 448         /* There should be one of more OPP defined */
 449         if (WARN_ON(!count)) {
 450                 ret = -ENOENT;
 451                 goto put_list_kref;
 452         }
 453
 454         list_for_each_entry(opp, &opp_table->opp_list, node)
 455                 pstate_count += !!opp->pstate;
 456
 457         /* Either all or none of the nodes shall have performance state set */
 458         if (pstate_count && pstate_count != count) {
 459                 dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
 460                         count, pstate_count);
 461                 ret = -ENOENT;
 462                 goto put_list_kref;
 463         }
 464
 465         if (pstate_count)
 466                 opp_table->genpd_performance_state = true;
 467
 468         opp_table->parsed_static_opps = true;
 469
 470         return 0;
 471
 472 put_list_kref:
 473         _put_opp_list_kref(opp_table);
 474
 475         return ret;
 476 }
 477
 478 /* Initializes OPP tables based on old-deprecated bindings */
 479 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 480 {
 481         const struct property *prop;
 482         const __be32 *val;
 483         int nr, ret = 0;
 484
 485         prop = of_find_property(dev->of_node, "operating-points", NULL);
 486         if (!prop)
 487                 return -ENODEV;
 488         if (!prop->value)
 489                 return -ENODATA;
 490
 491         /*
 492          * Each OPP is a set of tuples consisting of frequency and
 493          * voltage like <freq-kHz vol-uV>.
 494          */
 495         nr = prop->length / sizeof(u32);
 496         if (nr % 2) {
 497                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
 498                 return -EINVAL;
 499         }
 500
 501         kref_init(&opp_table->list_kref);
 502
 503         val = prop->value;
 504         while (nr) {
 505                 unsigned long freq = be32_to_cpup(val++) * 1000;
 506                 unsigned long volt = be32_to_cpup(val++);
 507
 508                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
 509                 if (ret) {
 510                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
 511                                 __func__, freq, ret);
 512                         _put_opp_list_kref(opp_table);
 513                         return ret;
 514                 }
 515                 nr -= 2;
 516         }
 517
 518         return ret;
 519 }
 520
 521 /**
 522  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
 523  * @dev:        device pointer used to lookup OPP table.
 524  *
 525  * Register the initial OPP table with the OPP library for given device.
 526  *
 527  * Return:
 528  * 0            On success OR
 529  *              Duplicate OPPs (both freq and volt are same) and opp->available
 530  * -EEXIST      Freq are same and volt are different OR
 531  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 532  * -ENOMEM      Memory allocation failure
 533  * -ENODEV      when 'operating-points' property is not found or is invalid data
 534  *              in device node.
 535  * -ENODATA     when empty 'operating-points' property is found
 536  * -EINVAL      when invalid entries are found in opp-v2 table
 537  */
 538 int dev_pm_opp_of_add_table(struct device *dev)
 539 {
 540         struct opp_table *opp_table;
 541         int ret;
 542
 543         opp_table = dev_pm_opp_get_opp_table_indexed(dev, 0);
 544         if (!opp_table)
 545                 return -ENOMEM;
 546
 547         /*
 548          * OPPs have two version of bindings now. Also try the old (v1)
 549          * bindings for backward compatibility with older dtbs.
 550          */
 551         if (opp_table->np)
 552                 ret = _of_add_opp_table_v2(dev, opp_table);
 553         else
 554                 ret = _of_add_opp_table_v1(dev, opp_table);
 555
 556         if (ret)
 557                 dev_pm_opp_put_opp_table(opp_table);
 558
 559         return ret;
 560 }
 561 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
 562
 563 /**
 564  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
 565  * @dev:        device pointer used to lookup OPP table.
 566  * @index:      Index number.
 567  *
 568  * Register the initial OPP table with the OPP library for given device only
 569  * using the "operating-points-v2" property.
 570  *
 571  * Return:
 572  * 0            On success OR
 573  *              Duplicate OPPs (both freq and volt are same) and opp->available
 574  * -EEXIST      Freq are same and volt are different OR
 575  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 576  * -ENOMEM      Memory allocation failure
 577  * -ENODEV      when 'operating-points' property is not found or is invalid data
 578  *              in device node.
 579  * -ENODATA     when empty 'operating-points' property is found
 580  * -EINVAL      when invalid entries are found in opp-v2 table
 581  */
 582 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
 583 {
 584         struct opp_table *opp_table;
 585         int ret, count;
 586
 587         if (index) {
 588                 /*
 589                  * If only one phandle is present, then the same OPP table
 590                  * applies for all index requests.
 591                  */
 592                 count = of_count_phandle_with_args(dev->of_node,
 593                                                    "operating-points-v2", NULL);
 594                 if (count == 1)
 595                         index = 0;
 596         }
 597
 598         opp_table = dev_pm_opp_get_opp_table_indexed(dev, index);
 599         if (!opp_table)
 600                 return -ENOMEM;
 601
 602         ret = _of_add_opp_table_v2(dev, opp_table);
 603         if (ret)
 604                 dev_pm_opp_put_opp_table(opp_table);
 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;
 635
 636         if (WARN_ON(cpumask_empty(cpumask)))
 637                 return -ENODEV;
 638
 639         for_each_cpu(cpu, cpumask) {
 640                 cpu_dev = get_cpu_device(cpu);
 641                 if (!cpu_dev) {
 642                         pr_err("%s: failed to get cpu%d device\n", __func__,
 643                                cpu);
 644                         ret = -ENODEV;
 645                         goto remove_table;
 646                 }
 647
 648                 ret = dev_pm_opp_of_add_table(cpu_dev);
 649                 if (ret) {
 650                         /*
 651                          * OPP may get registered dynamically, don't print error
 652                          * message here.
 653                          */
 654                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
 655                                  __func__, cpu, ret);
 656
 657                         goto remove_table;
 658                 }
 659         }
 660
 661         return 0;
 662
 663 remove_table:
 664         /* Free all other OPPs */
 665         _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
 666
 667         return ret;
 668 }
 669 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
 670
 671 /*
 672  * Works only for OPP v2 bindings.
 673  *
 674  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
 675  */
 676 /**
 677  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
 678  *                                    @cpu_dev using operating-points-v2
 679  *                                    bindings.
 680  *
 681  * @cpu_dev:    CPU device for which we do this operation
 682  * @cpumask:    cpumask to update with information of sharing CPUs
 683  *
 684  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 685  *
 686  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
 687  */
 688 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
 689                                    struct cpumask *cpumask)
 690 {
 691         struct device_node *np, *tmp_np, *cpu_np;
 692         int cpu, ret = 0;
 693
 694         /* Get OPP descriptor node */
 695         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
 696         if (!np) {
 697                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
 698                 return -ENOENT;
 699         }
 700
 701         cpumask_set_cpu(cpu_dev->id, cpumask);
 702
 703         /* OPPs are shared ? */
 704         if (!of_property_read_bool(np, "opp-shared"))
 705                 goto put_cpu_node;
 706
 707         for_each_possible_cpu(cpu) {
 708                 if (cpu == cpu_dev->id)
 709                         continue;
 710
 711                 cpu_np = of_cpu_device_node_get(cpu);
 712                 if (!cpu_np) {
 713                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
 714                                 __func__, cpu);
 715                         ret = -ENOENT;
 716                         goto put_cpu_node;
 717                 }
 718
 719                 /* Get OPP descriptor node */
 720                 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
 721                 of_node_put(cpu_np);
 722                 if (!tmp_np) {
 723                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
 724                         ret = -ENOENT;
 725                         goto put_cpu_node;
 726                 }
 727
 728                 /* CPUs are sharing opp node */
 729                 if (np == tmp_np)
 730                         cpumask_set_cpu(cpu, cpumask);
 731
 732                 of_node_put(tmp_np);
 733         }
 734
 735 put_cpu_node:
 736         of_node_put(np);
 737         return ret;
 738 }
 739 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
 740
 741 /**
 742  * of_dev_pm_opp_find_required_opp() - Search for required OPP.
 743  * @dev: The device whose OPP node is referenced by the 'np' DT node.
 744  * @np: Node that contains the "required-opps" property.
 745  *
 746  * Returns the OPP of the device 'dev', whose phandle is present in the "np"
 747  * node. Although the "required-opps" property supports having multiple
 748  * phandles, this helper routine only parses the very first phandle in the list.
 749  *
 750  * Return: Matching opp, else returns ERR_PTR in case of error and should be
 751  * handled using IS_ERR.
 752  *
 753  * The callers are required to call dev_pm_opp_put() for the returned OPP after
 754  * use.
 755  */
 756 struct dev_pm_opp *of_dev_pm_opp_find_required_opp(struct device *dev,
 757                                                    struct device_node *np)
 758 {
 759         struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ENODEV);
 760         struct device_node *required_np;
 761         struct opp_table *opp_table;
 762
 763         opp_table = _find_opp_table(dev);
 764         if (IS_ERR(opp_table))
 765                 return ERR_CAST(opp_table);
 766
 767         required_np = of_parse_phandle(np, "required-opps", 0);
 768         if (unlikely(!required_np)) {
 769                 dev_err(dev, "Unable to parse required-opps\n");
 770                 goto put_opp_table;
 771         }
 772
 773         mutex_lock(&opp_table->lock);
 774
 775         list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
 776                 if (temp_opp->available && temp_opp->np == required_np) {
 777                         opp = temp_opp;
 778
 779                         /* Increment the reference count of OPP */
 780                         dev_pm_opp_get(opp);
 781                         break;
 782                 }
 783         }
 784
 785         mutex_unlock(&opp_table->lock);
 786
 787         of_node_put(required_np);
 788 put_opp_table:
 789         dev_pm_opp_put_opp_table(opp_table);
 790
 791         return opp;
 792 }
 793 EXPORT_SYMBOL_GPL(of_dev_pm_opp_find_required_opp);
 794
 795 /**
 796  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
 797  * @opp:        opp for which DT node has to be returned for
 798  *
 799  * Return: DT node corresponding to the opp, else 0 on success.
 800  *
 801  * The caller needs to put the node with of_node_put() after using it.
 802  */
 803 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
 804 {
 805         if (IS_ERR_OR_NULL(opp)) {
 806                 pr_err("%s: Invalid parameters\n", __func__);
 807                 return NULL;
 808         }
 809
 810         return of_node_get(opp->np);
 811 }
 812 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);