drivers/base/power/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.h>
  20 #include <linux/slab.h>
  21 #include <linux/export.h>
  22
  23 #include "opp.h"
  24
  25 static struct opp_table *_managed_opp(const struct device_node *np)
  26 {
  27         struct opp_table *opp_table, *managed_table = NULL;
  28
  29         mutex_lock(&opp_table_lock);
  30
  31         list_for_each_entry(opp_table, &opp_tables, node) {
  32                 if (opp_table->np == np) {
  33                         /*
  34                          * Multiple devices can point to the same OPP table and
  35                          * so will have same node-pointer, np.
  36                          *
  37                          * But the OPPs will be considered as shared only if the
  38                          * OPP table contains a "opp-shared" property.
  39                          */
  40                         if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
  41                                 _get_opp_table_kref(opp_table);
  42                                 managed_table = opp_table;
  43                         }
  44
  45                         break;
  46                 }
  47         }
  48
  49         mutex_unlock(&opp_table_lock);
  50
  51         return managed_table;
  52 }
  53
  54 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev)
  55 {
  56         struct device_node *np;
  57
  58         /*
  59          * Only required for backward compatibility with v1 bindings, but isn't
  60          * harmful for other cases. And so we do it unconditionally.
  61          */
  62         np = of_node_get(dev->of_node);
  63         if (np) {
  64                 u32 val;
  65
  66                 if (!of_property_read_u32(np, "clock-latency", &val))
  67                         opp_table->clock_latency_ns_max = val;
  68                 of_property_read_u32(np, "voltage-tolerance",
  69                                      &opp_table->voltage_tolerance_v1);
  70                 of_node_put(np);
  71         }
  72 }
  73
  74 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
  75                               struct device_node *np)
  76 {
  77         unsigned int count = opp_table->supported_hw_count;
  78         u32 version;
  79         int ret;
  80
  81         if (!opp_table->supported_hw) {
  82                 /*
  83                  * In the case that no supported_hw has been set by the
  84                  * platform but there is an opp-supported-hw value set for
  85                  * an OPP then the OPP should not be enabled as there is
  86                  * no way to see if the hardware supports it.
  87                  */
  88                 if (of_find_property(np, "opp-supported-hw", NULL))
  89                         return false;
  90                 else
  91                         return true;
  92         }
  93
  94         while (count--) {
  95                 ret = of_property_read_u32_index(np, "opp-supported-hw", count,
  96                                                  &version);
  97                 if (ret) {
  98                         dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
  99                                  __func__, count, ret);
 100                         return false;
 101                 }
 102
 103                 /* Both of these are bitwise masks of the versions */
 104                 if (!(version & opp_table->supported_hw[count]))
 105                         return false;
 106         }
 107
 108         return true;
 109 }
 110
 111 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 112                               struct opp_table *opp_table)
 113 {
 114         u32 *microvolt, *microamp = NULL;
 115         int supplies, vcount, icount, ret, i, j;
 116         struct property *prop = NULL;
 117         char name[NAME_MAX];
 118
 119         supplies = opp_table->regulator_count ? opp_table->regulator_count : 1;
 120
 121         /* Search for "opp-microvolt-<name>" */
 122         if (opp_table->prop_name) {
 123                 snprintf(name, sizeof(name), "opp-microvolt-%s",
 124                          opp_table->prop_name);
 125                 prop = of_find_property(opp->np, name, NULL);
 126         }
 127
 128         if (!prop) {
 129                 /* Search for "opp-microvolt" */
 130                 sprintf(name, "opp-microvolt");
 131                 prop = of_find_property(opp->np, name, NULL);
 132
 133                 /* Missing property isn't a problem, but an invalid entry is */
 134                 if (!prop) {
 135                         if (!opp_table->regulator_count)
 136                                 return 0;
 137
 138                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
 139                                 __func__);
 140                         return -EINVAL;
 141                 }
 142         }
 143
 144         vcount = of_property_count_u32_elems(opp->np, name);
 145         if (vcount < 0) {
 146                 dev_err(dev, "%s: Invalid %s property (%d)\n",
 147                         __func__, name, vcount);
 148                 return vcount;
 149         }
 150
 151         /* There can be one or three elements per supply */
 152         if (vcount != supplies && vcount != supplies * 3) {
 153                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 154                         __func__, name, vcount, supplies);
 155                 return -EINVAL;
 156         }
 157
 158         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
 159         if (!microvolt)
 160                 return -ENOMEM;
 161
 162         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
 163         if (ret) {
 164                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 165                 ret = -EINVAL;
 166                 goto free_microvolt;
 167         }
 168
 169         /* Search for "opp-microamp-<name>" */
 170         prop = NULL;
 171         if (opp_table->prop_name) {
 172                 snprintf(name, sizeof(name), "opp-microamp-%s",
 173                          opp_table->prop_name);
 174                 prop = of_find_property(opp->np, name, NULL);
 175         }
 176
 177         if (!prop) {
 178                 /* Search for "opp-microamp" */
 179                 sprintf(name, "opp-microamp");
 180                 prop = of_find_property(opp->np, name, NULL);
 181         }
 182
 183         if (prop) {
 184                 icount = of_property_count_u32_elems(opp->np, name);
 185                 if (icount < 0) {
 186                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
 187                                 name, icount);
 188                         ret = icount;
 189                         goto free_microvolt;
 190                 }
 191
 192                 if (icount != supplies) {
 193                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
 194                                 __func__, name, icount, supplies);
 195                         ret = -EINVAL;
 196                         goto free_microvolt;
 197                 }
 198
 199                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
 200                 if (!microamp) {
 201                         ret = -EINVAL;
 202                         goto free_microvolt;
 203                 }
 204
 205                 ret = of_property_read_u32_array(opp->np, name, microamp,
 206                                                  icount);
 207                 if (ret) {
 208                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
 209                                 name, ret);
 210                         ret = -EINVAL;
 211                         goto free_microamp;
 212                 }
 213         }
 214
 215         for (i = 0, j = 0; i < supplies; i++) {
 216                 opp->supplies[i].u_volt = microvolt[j++];
 217
 218                 if (vcount == supplies) {
 219                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
 220                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
 221                 } else {
 222                         opp->supplies[i].u_volt_min = microvolt[j++];
 223                         opp->supplies[i].u_volt_max = microvolt[j++];
 224                 }
 225
 226                 if (microamp)
 227                         opp->supplies[i].u_amp = microamp[i];
 228         }
 229
 230 free_microamp:
 231         kfree(microamp);
 232 free_microvolt:
 233         kfree(microvolt);
 234
 235         return ret;
 236 }
 237
 238 /**
 239  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 240  *                                entries
 241  * @dev:        device pointer used to lookup OPP table.
 242  *
 243  * Free OPPs created using static entries present in DT.
 244  */
 245 void dev_pm_opp_of_remove_table(struct device *dev)
 246 {
 247         _dev_pm_opp_find_and_remove_table(dev, false);
 248 }
 249 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 250
 251 /* Returns opp descriptor node for a device, caller must do of_node_put() */
 252 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
 253 {
 254         /*
 255          * There should be only ONE phandle present in "operating-points-v2"
 256          * property.
 257          */
 258
 259         return of_parse_phandle(dev->of_node, "operating-points-v2", 0);
 260 }
 261 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
 262
 263 /**
 264  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 265  * @opp_table:  OPP table
 266  * @dev:        device for which we do this operation
 267  * @np:         device node
 268  *
 269  * This function adds an opp definition to the opp table and returns status. The
 270  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 271  * removed by dev_pm_opp_remove.
 272  *
 273  * Return:
 274  * 0            On success OR
 275  *              Duplicate OPPs (both freq and volt are same) and opp->available
 276  * -EEXIST      Freq are same and volt are different OR
 277  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 278  * -ENOMEM      Memory allocation failure
 279  * -EINVAL      Failed parsing the OPP node
 280  */
 281 static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev,
 282                               struct device_node *np)
 283 {
 284         struct dev_pm_opp *new_opp;
 285         u64 rate;
 286         u32 val;
 287         int ret;
 288
 289         new_opp = _opp_allocate(opp_table);
 290         if (!new_opp)
 291                 return -ENOMEM;
 292
 293         ret = of_property_read_u64(np, "opp-hz", &rate);
 294         if (ret < 0) {
 295                 dev_err(dev, "%s: opp-hz not found\n", __func__);
 296                 goto free_opp;
 297         }
 298
 299         /* Check if the OPP supports hardware's hierarchy of versions or not */
 300         if (!_opp_is_supported(dev, opp_table, np)) {
 301                 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
 302                 goto free_opp;
 303         }
 304
 305         /*
 306          * Rate is defined as an unsigned long in clk API, and so casting
 307          * explicitly to its type. Must be fixed once rate is 64 bit
 308          * guaranteed in clk API.
 309          */
 310         new_opp->rate = (unsigned long)rate;
 311         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 312
 313         new_opp->np = np;
 314         new_opp->dynamic = false;
 315         new_opp->available = true;
 316
 317         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 318                 new_opp->clock_latency_ns = val;
 319
 320         ret = opp_parse_supplies(new_opp, dev, opp_table);
 321         if (ret)
 322                 goto free_opp;
 323
 324         ret = _opp_add(dev, new_opp, opp_table);
 325         if (ret) {
 326                 /* Don't return error for duplicate OPPs */
 327                 if (ret == -EBUSY)
 328                         ret = 0;
 329                 goto free_opp;
 330         }
 331
 332         /* OPP to select on device suspend */
 333         if (of_property_read_bool(np, "opp-suspend")) {
 334                 if (opp_table->suspend_opp) {
 335                         dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
 336                                  __func__, opp_table->suspend_opp->rate,
 337                                  new_opp->rate);
 338                 } else {
 339                         new_opp->suspend = true;
 340                         opp_table->suspend_opp = new_opp;
 341                 }
 342         }
 343
 344         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 345                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 346
 347         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
 348                  __func__, new_opp->turbo, new_opp->rate,
 349                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 350                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
 351
 352         /*
 353          * Notify the changes in the availability of the operable
 354          * frequency/voltage list.
 355          */
 356         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
 357         return 0;
 358
 359 free_opp:
 360         _opp_free(new_opp);
 361
 362         return ret;
 363 }
 364
 365 /* Initializes OPP tables based on new bindings */
 366 static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
 367 {
 368         struct device_node *np;
 369         struct opp_table *opp_table;
 370         int ret = 0, count = 0;
 371
 372         opp_table = _managed_opp(opp_np);
 373         if (opp_table) {
 374                 /* OPPs are already managed */
 375                 if (!_add_opp_dev(dev, opp_table))
 376                         ret = -ENOMEM;
 377                 goto put_opp_table;
 378         }
 379
 380         opp_table = dev_pm_opp_get_opp_table(dev);
 381         if (!opp_table)
 382                 return -ENOMEM;
 383
 384         /* We have opp-table node now, iterate over it and add OPPs */
 385         for_each_available_child_of_node(opp_np, np) {
 386                 count++;
 387
 388                 ret = _opp_add_static_v2(opp_table, dev, np);
 389                 if (ret) {
 390                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 391                                 ret);
 392                         _dev_pm_opp_remove_table(opp_table, dev, false);
 393                         goto put_opp_table;
 394                 }
 395         }
 396
 397         /* There should be one of more OPP defined */
 398         if (WARN_ON(!count)) {
 399                 ret = -ENOENT;
 400                 goto put_opp_table;
 401         }
 402
 403         opp_table->np = opp_np;
 404         if (of_property_read_bool(opp_np, "opp-shared"))
 405                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
 406         else
 407                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
 408
 409 put_opp_table:
 410         dev_pm_opp_put_opp_table(opp_table);
 411
 412         return ret;
 413 }
 414
 415 /* Initializes OPP tables based on old-deprecated bindings */
 416 static int _of_add_opp_table_v1(struct device *dev)
 417 {
 418         struct opp_table *opp_table;
 419         const struct property *prop;
 420         const __be32 *val;
 421         int nr, ret = 0;
 422
 423         prop = of_find_property(dev->of_node, "operating-points", NULL);
 424         if (!prop)
 425                 return -ENODEV;
 426         if (!prop->value)
 427                 return -ENODATA;
 428
 429         /*
 430          * Each OPP is a set of tuples consisting of frequency and
 431          * voltage like <freq-kHz vol-uV>.
 432          */
 433         nr = prop->length / sizeof(u32);
 434         if (nr % 2) {
 435                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
 436                 return -EINVAL;
 437         }
 438
 439         opp_table = dev_pm_opp_get_opp_table(dev);
 440         if (!opp_table)
 441                 return -ENOMEM;
 442
 443         val = prop->value;
 444         while (nr) {
 445                 unsigned long freq = be32_to_cpup(val++) * 1000;
 446                 unsigned long volt = be32_to_cpup(val++);
 447
 448                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
 449                 if (ret) {
 450                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
 451                                 __func__, freq, ret);
 452                         _dev_pm_opp_remove_table(opp_table, dev, false);
 453                         break;
 454                 }
 455                 nr -= 2;
 456         }
 457
 458         dev_pm_opp_put_opp_table(opp_table);
 459         return ret;
 460 }
 461
 462 /**
 463  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
 464  * @dev:        device pointer used to lookup OPP table.
 465  *
 466  * Register the initial OPP table with the OPP library for given device.
 467  *
 468  * Return:
 469  * 0            On success OR
 470  *              Duplicate OPPs (both freq and volt are same) and opp->available
 471  * -EEXIST      Freq are same and volt are different OR
 472  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 473  * -ENOMEM      Memory allocation failure
 474  * -ENODEV      when 'operating-points' property is not found or is invalid data
 475  *              in device node.
 476  * -ENODATA     when empty 'operating-points' property is found
 477  * -EINVAL      when invalid entries are found in opp-v2 table
 478  */
 479 int dev_pm_opp_of_add_table(struct device *dev)
 480 {
 481         struct device_node *opp_np;
 482         int ret;
 483
 484         /*
 485          * OPPs have two version of bindings now. The older one is deprecated,
 486          * try for the new binding first.
 487          */
 488         opp_np = dev_pm_opp_of_get_opp_desc_node(dev);
 489         if (!opp_np) {
 490                 /*
 491                  * Try old-deprecated bindings for backward compatibility with
 492                  * older dtbs.
 493                  */
 494                 return _of_add_opp_table_v1(dev);
 495         }
 496
 497         ret = _of_add_opp_table_v2(dev, opp_np);
 498         of_node_put(opp_np);
 499
 500         return ret;
 501 }
 502 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
 503
 504 /* CPU device specific helpers */
 505
 506 /**
 507  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
 508  * @cpumask:    cpumask for which OPP table needs to be removed
 509  *
 510  * This removes the OPP tables for CPUs present in the @cpumask.
 511  * This should be used only to remove static entries created from DT.
 512  */
 513 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
 514 {
 515         _dev_pm_opp_cpumask_remove_table(cpumask, true);
 516 }
 517 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
 518
 519 /**
 520  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
 521  * @cpumask:    cpumask for which OPP table needs to be added.
 522  *
 523  * This adds the OPP tables for CPUs present in the @cpumask.
 524  */
 525 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
 526 {
 527         struct device *cpu_dev;
 528         int cpu, ret = 0;
 529
 530         WARN_ON(cpumask_empty(cpumask));
 531
 532         for_each_cpu(cpu, cpumask) {
 533                 cpu_dev = get_cpu_device(cpu);
 534                 if (!cpu_dev) {
 535                         pr_err("%s: failed to get cpu%d device\n", __func__,
 536                                cpu);
 537                         continue;
 538                 }
 539
 540                 ret = dev_pm_opp_of_add_table(cpu_dev);
 541                 if (ret) {
 542                         pr_err("%s: couldn't find opp table for cpu:%d, %d\n",
 543                                __func__, cpu, ret);
 544
 545                         /* Free all other OPPs */
 546                         dev_pm_opp_of_cpumask_remove_table(cpumask);
 547                         break;
 548                 }
 549         }
 550
 551         return ret;
 552 }
 553 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
 554
 555 /*
 556  * Works only for OPP v2 bindings.
 557  *
 558  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
 559  */
 560 /**
 561  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
 562  *                                    @cpu_dev using operating-points-v2
 563  *                                    bindings.
 564  *
 565  * @cpu_dev:    CPU device for which we do this operation
 566  * @cpumask:    cpumask to update with information of sharing CPUs
 567  *
 568  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 569  *
 570  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
 571  */
 572 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
 573                                    struct cpumask *cpumask)
 574 {
 575         struct device_node *np, *tmp_np;
 576         struct device *tcpu_dev;
 577         int cpu, ret = 0;
 578
 579         /* Get OPP descriptor node */
 580         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
 581         if (!np) {
 582                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
 583                 return -ENOENT;
 584         }
 585
 586         cpumask_set_cpu(cpu_dev->id, cpumask);
 587
 588         /* OPPs are shared ? */
 589         if (!of_property_read_bool(np, "opp-shared"))
 590                 goto put_cpu_node;
 591
 592         for_each_possible_cpu(cpu) {
 593                 if (cpu == cpu_dev->id)
 594                         continue;
 595
 596                 tcpu_dev = get_cpu_device(cpu);
 597                 if (!tcpu_dev) {
 598                         dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
 599                                 __func__, cpu);
 600                         ret = -ENODEV;
 601                         goto put_cpu_node;
 602                 }
 603
 604                 /* Get OPP descriptor node */
 605                 tmp_np = dev_pm_opp_of_get_opp_desc_node(tcpu_dev);
 606                 if (!tmp_np) {
 607                         dev_err(tcpu_dev, "%s: Couldn't find opp node.\n",
 608                                 __func__);
 609                         ret = -ENOENT;
 610                         goto put_cpu_node;
 611                 }
 612
 613                 /* CPUs are sharing opp node */
 614                 if (np == tmp_np)
 615                         cpumask_set_cpu(cpu, cpumask);
 616
 617                 of_node_put(tmp_np);
 618         }
 619
 620 put_cpu_node:
 621         of_node_put(np);
 622         return ret;
 623 }
 624 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);