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/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 node, caller must
 252  * do of_node_put() */
 253 static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np)
 254 {
 255         /*
 256          * There should be only ONE phandle present in "operating-points-v2"
 257          * property.
 258          */
 259
 260         return of_parse_phandle(np, "operating-points-v2", 0);
 261 }
 262
 263 /* Returns opp descriptor node for a device, caller must do of_node_put() */
 264 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
 265 {
 266         return _opp_of_get_opp_desc_node(dev->of_node);
 267 }
 268 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
 269
 270 /**
 271  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 272  * @opp_table:  OPP table
 273  * @dev:        device for which we do this operation
 274  * @np:         device node
 275  *
 276  * This function adds an opp definition to the opp table and returns status. The
 277  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 278  * removed by dev_pm_opp_remove.
 279  *
 280  * Return:
 281  * 0            On success OR
 282  *              Duplicate OPPs (both freq and volt are same) and opp->available
 283  * -EEXIST      Freq are same and volt are different OR
 284  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 285  * -ENOMEM      Memory allocation failure
 286  * -EINVAL      Failed parsing the OPP node
 287  */
 288 static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev,
 289                               struct device_node *np)
 290 {
 291         struct dev_pm_opp *new_opp;
 292         u64 rate;
 293         u32 val;
 294         int ret;
 295
 296         new_opp = _opp_allocate(opp_table);
 297         if (!new_opp)
 298                 return -ENOMEM;
 299
 300         ret = of_property_read_u64(np, "opp-hz", &rate);
 301         if (ret < 0) {
 302                 dev_err(dev, "%s: opp-hz not found\n", __func__);
 303                 goto free_opp;
 304         }
 305
 306         /* Check if the OPP supports hardware's hierarchy of versions or not */
 307         if (!_opp_is_supported(dev, opp_table, np)) {
 308                 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
 309                 goto free_opp;
 310         }
 311
 312         /*
 313          * Rate is defined as an unsigned long in clk API, and so casting
 314          * explicitly to its type. Must be fixed once rate is 64 bit
 315          * guaranteed in clk API.
 316          */
 317         new_opp->rate = (unsigned long)rate;
 318         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
 319
 320         new_opp->np = np;
 321         new_opp->dynamic = false;
 322         new_opp->available = true;
 323
 324         if (!of_property_read_u32(np, "clock-latency-ns", &val))
 325                 new_opp->clock_latency_ns = val;
 326
 327         ret = opp_parse_supplies(new_opp, dev, opp_table);
 328         if (ret)
 329                 goto free_opp;
 330
 331         ret = _opp_add(dev, new_opp, opp_table);
 332         if (ret) {
 333                 /* Don't return error for duplicate OPPs */
 334                 if (ret == -EBUSY)
 335                         ret = 0;
 336                 goto free_opp;
 337         }
 338
 339         /* OPP to select on device suspend */
 340         if (of_property_read_bool(np, "opp-suspend")) {
 341                 if (opp_table->suspend_opp) {
 342                         dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
 343                                  __func__, opp_table->suspend_opp->rate,
 344                                  new_opp->rate);
 345                 } else {
 346                         new_opp->suspend = true;
 347                         opp_table->suspend_opp = new_opp;
 348                 }
 349         }
 350
 351         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
 352                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
 353
 354         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
 355                  __func__, new_opp->turbo, new_opp->rate,
 356                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
 357                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
 358
 359         /*
 360          * Notify the changes in the availability of the operable
 361          * frequency/voltage list.
 362          */
 363         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
 364         return 0;
 365
 366 free_opp:
 367         _opp_free(new_opp);
 368
 369         return ret;
 370 }
 371
 372 /* Initializes OPP tables based on new bindings */
 373 static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
 374 {
 375         struct device_node *np;
 376         struct opp_table *opp_table;
 377         int ret = 0, count = 0;
 378
 379         opp_table = _managed_opp(opp_np);
 380         if (opp_table) {
 381                 /* OPPs are already managed */
 382                 if (!_add_opp_dev(dev, opp_table))
 383                         ret = -ENOMEM;
 384                 goto put_opp_table;
 385         }
 386
 387         opp_table = dev_pm_opp_get_opp_table(dev);
 388         if (!opp_table)
 389                 return -ENOMEM;
 390
 391         /* We have opp-table node now, iterate over it and add OPPs */
 392         for_each_available_child_of_node(opp_np, np) {
 393                 count++;
 394
 395                 ret = _opp_add_static_v2(opp_table, dev, np);
 396                 if (ret) {
 397                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 398                                 ret);
 399                         _dev_pm_opp_remove_table(opp_table, dev, false);
 400                         of_node_put(np);
 401                         goto put_opp_table;
 402                 }
 403         }
 404
 405         /* There should be one of more OPP defined */
 406         if (WARN_ON(!count)) {
 407                 ret = -ENOENT;
 408                 goto put_opp_table;
 409         }
 410
 411         opp_table->np = opp_np;
 412         if (of_property_read_bool(opp_np, "opp-shared"))
 413                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
 414         else
 415                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
 416
 417 put_opp_table:
 418         dev_pm_opp_put_opp_table(opp_table);
 419
 420         return ret;
 421 }
 422
 423 /* Initializes OPP tables based on old-deprecated bindings */
 424 static int _of_add_opp_table_v1(struct device *dev)
 425 {
 426         struct opp_table *opp_table;
 427         const struct property *prop;
 428         const __be32 *val;
 429         int nr, ret = 0;
 430
 431         prop = of_find_property(dev->of_node, "operating-points", NULL);
 432         if (!prop)
 433                 return -ENODEV;
 434         if (!prop->value)
 435                 return -ENODATA;
 436
 437         /*
 438          * Each OPP is a set of tuples consisting of frequency and
 439          * voltage like <freq-kHz vol-uV>.
 440          */
 441         nr = prop->length / sizeof(u32);
 442         if (nr % 2) {
 443                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
 444                 return -EINVAL;
 445         }
 446
 447         opp_table = dev_pm_opp_get_opp_table(dev);
 448         if (!opp_table)
 449                 return -ENOMEM;
 450
 451         val = prop->value;
 452         while (nr) {
 453                 unsigned long freq = be32_to_cpup(val++) * 1000;
 454                 unsigned long volt = be32_to_cpup(val++);
 455
 456                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
 457                 if (ret) {
 458                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
 459                                 __func__, freq, ret);
 460                         _dev_pm_opp_remove_table(opp_table, dev, false);
 461                         break;
 462                 }
 463                 nr -= 2;
 464         }
 465
 466         dev_pm_opp_put_opp_table(opp_table);
 467         return ret;
 468 }
 469
 470 /**
 471  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
 472  * @dev:        device pointer used to lookup OPP table.
 473  *
 474  * Register the initial OPP table with the OPP library for given device.
 475  *
 476  * Return:
 477  * 0            On success OR
 478  *              Duplicate OPPs (both freq and volt are same) and opp->available
 479  * -EEXIST      Freq are same and volt are different OR
 480  *              Duplicate OPPs (both freq and volt are same) and !opp->available
 481  * -ENOMEM      Memory allocation failure
 482  * -ENODEV      when 'operating-points' property is not found or is invalid data
 483  *              in device node.
 484  * -ENODATA     when empty 'operating-points' property is found
 485  * -EINVAL      when invalid entries are found in opp-v2 table
 486  */
 487 int dev_pm_opp_of_add_table(struct device *dev)
 488 {
 489         struct device_node *opp_np;
 490         int ret;
 491
 492         /*
 493          * OPPs have two version of bindings now. The older one is deprecated,
 494          * try for the new binding first.
 495          */
 496         opp_np = dev_pm_opp_of_get_opp_desc_node(dev);
 497         if (!opp_np) {
 498                 /*
 499                  * Try old-deprecated bindings for backward compatibility with
 500                  * older dtbs.
 501                  */
 502                 return _of_add_opp_table_v1(dev);
 503         }
 504
 505         ret = _of_add_opp_table_v2(dev, opp_np);
 506         of_node_put(opp_np);
 507
 508         return ret;
 509 }
 510 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
 511
 512 /* CPU device specific helpers */
 513
 514 /**
 515  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
 516  * @cpumask:    cpumask for which OPP table needs to be removed
 517  *
 518  * This removes the OPP tables for CPUs present in the @cpumask.
 519  * This should be used only to remove static entries created from DT.
 520  */
 521 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
 522 {
 523         _dev_pm_opp_cpumask_remove_table(cpumask, true);
 524 }
 525 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
 526
 527 /**
 528  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
 529  * @cpumask:    cpumask for which OPP table needs to be added.
 530  *
 531  * This adds the OPP tables for CPUs present in the @cpumask.
 532  */
 533 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
 534 {
 535         struct device *cpu_dev;
 536         int cpu, ret = 0;
 537
 538         WARN_ON(cpumask_empty(cpumask));
 539
 540         for_each_cpu(cpu, cpumask) {
 541                 cpu_dev = get_cpu_device(cpu);
 542                 if (!cpu_dev) {
 543                         pr_err("%s: failed to get cpu%d device\n", __func__,
 544                                cpu);
 545                         continue;
 546                 }
 547
 548                 ret = dev_pm_opp_of_add_table(cpu_dev);
 549                 if (ret) {
 550                         /*
 551                          * OPP may get registered dynamically, don't print error
 552                          * message here.
 553                          */
 554                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
 555                                  __func__, cpu, ret);
 556
 557                         /* Free all other OPPs */
 558                         dev_pm_opp_of_cpumask_remove_table(cpumask);
 559                         break;
 560                 }
 561         }
 562
 563         return ret;
 564 }
 565 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
 566
 567 /*
 568  * Works only for OPP v2 bindings.
 569  *
 570  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
 571  */
 572 /**
 573  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
 574  *                                    @cpu_dev using operating-points-v2
 575  *                                    bindings.
 576  *
 577  * @cpu_dev:    CPU device for which we do this operation
 578  * @cpumask:    cpumask to update with information of sharing CPUs
 579  *
 580  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 581  *
 582  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
 583  */
 584 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
 585                                    struct cpumask *cpumask)
 586 {
 587         struct device_node *np, *tmp_np, *cpu_np;
 588         int cpu, ret = 0;
 589
 590         /* Get OPP descriptor node */
 591         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
 592         if (!np) {
 593                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
 594                 return -ENOENT;
 595         }
 596
 597         cpumask_set_cpu(cpu_dev->id, cpumask);
 598
 599         /* OPPs are shared ? */
 600         if (!of_property_read_bool(np, "opp-shared"))
 601                 goto put_cpu_node;
 602
 603         for_each_possible_cpu(cpu) {
 604                 if (cpu == cpu_dev->id)
 605                         continue;
 606
 607                 cpu_np = of_cpu_device_node_get(cpu);
 608                 if (!cpu_np) {
 609                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
 610                                 __func__, cpu);
 611                         ret = -ENOENT;
 612                         goto put_cpu_node;
 613                 }
 614
 615                 /* Get OPP descriptor node */
 616                 tmp_np = _opp_of_get_opp_desc_node(cpu_np);
 617                 of_node_put(cpu_np);
 618                 if (!tmp_np) {
 619                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
 620                         ret = -ENOENT;
 621                         goto put_cpu_node;
 622                 }
 623
 624                 /* CPUs are sharing opp node */
 625                 if (np == tmp_np)
 626                         cpumask_set_cpu(cpu, cpumask);
 627
 628                 of_node_put(tmp_np);
 629         }
 630
 631 put_cpu_node:
 632         of_node_put(np);
 633         return ret;
 634 }
 635 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);