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