drivers/thermal/of-thermal.c

   1 /*
   2  *  of-thermal.c - Generic Thermal Management device tree support.
   3  *
   4  *  Copyright (C) 2013 Texas Instruments
   5  *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
   6  *
   7  *
   8  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; version 2 of the License.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25 #include <linux/thermal.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28 #include <linux/of_device.h>
  29 #include <linux/of_platform.h>
  30 #include <linux/err.h>
  31 #include <linux/export.h>
  32 #include <linux/string.h>
  33 #include <linux/thermal.h>
  34
  35 #include "thermal_core.h"
  36
  37 /***   Private data structures to represent thermal device tree data ***/
  38
  39 /**
  40  * struct __thermal_bind_param - a match between trip and cooling device
  41  * @cooling_device: a pointer to identify the referred cooling device
  42  * @trip_id: the trip point index
  43  * @usage: the percentage (from 0 to 100) of cooling contribution
  44  * @min: minimum cooling state used at this trip point
  45  * @max: maximum cooling state used at this trip point
  46  */
  47
  48 struct __thermal_bind_params {
  49         struct device_node *cooling_device;
  50         unsigned int trip_id;
  51         unsigned int usage;
  52         unsigned long min;
  53         unsigned long max;
  54 };
  55
  56 /**
  57  * struct __thermal_zone - internal representation of a thermal zone
  58  * @mode: current thermal zone device mode (enabled/disabled)
  59  * @passive_delay: polling interval while passive cooling is activated
  60  * @polling_delay: zone polling interval
  61  * @ntrips: number of trip points
  62  * @trips: an array of trip points (0..ntrips - 1)
  63  * @num_tbps: number of thermal bind params
  64  * @tbps: an array of thermal bind params (0..num_tbps - 1)
  65  * @sensor_data: sensor private data used while reading temperature and trend
  66  * @ops: set of callbacks to handle the thermal zone based on DT
  67  */
  68
  69 struct __thermal_zone {
  70         enum thermal_device_mode mode;
  71         int passive_delay;
  72         int polling_delay;
  73
  74         /* trip data */
  75         int ntrips;
  76         struct thermal_trip *trips;
  77
  78         /* cooling binding data */
  79         int num_tbps;
  80         struct __thermal_bind_params *tbps;
  81
  82         /* sensor interface */
  83         void *sensor_data;
  84         const struct thermal_zone_of_device_ops *ops;
  85 };
  86
  87 /***   DT thermal zone device callbacks   ***/
  88
  89 static int of_thermal_get_temp(struct thermal_zone_device *tz,
  90                                unsigned long *temp)
  91 {
  92         struct __thermal_zone *data = tz->devdata;
  93
  94         if (!data->ops->get_temp)
  95                 return -EINVAL;
  96
  97         return data->ops->get_temp(data->sensor_data, temp);
  98 }
  99
 100 /**
 101  * of_thermal_get_ntrips - function to export number of available trip
 102  *                         points.
 103  * @tz: pointer to a thermal zone
 104  *
 105  * This function is a globally visible wrapper to get number of trip points
 106  * stored in the local struct __thermal_zone
 107  *
 108  * Return: number of available trip points, -ENODEV when data not available
 109  */
 110 int of_thermal_get_ntrips(struct thermal_zone_device *tz)
 111 {
 112         struct __thermal_zone *data = tz->devdata;
 113
 114         if (!data || IS_ERR(data))
 115                 return -ENODEV;
 116
 117         return data->ntrips;
 118 }
 119 EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);
 120
 121 /**
 122  * of_thermal_is_trip_valid - function to check if trip point is valid
 123  *
 124  * @tz: pointer to a thermal zone
 125  * @trip:       trip point to evaluate
 126  *
 127  * This function is responsible for checking if passed trip point is valid
 128  *
 129  * Return: true if trip point is valid, false otherwise
 130  */
 131 bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
 132 {
 133         struct __thermal_zone *data = tz->devdata;
 134
 135         if (!data || trip >= data->ntrips || trip < 0)
 136                 return false;
 137
 138         return true;
 139 }
 140 EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);
 141
 142 /**
 143  * of_thermal_get_trip_points - function to get access to a globally exported
 144  *                              trip points
 145  *
 146  * @tz: pointer to a thermal zone
 147  *
 148  * This function provides a pointer to trip points table
 149  *
 150  * Return: pointer to trip points table, NULL otherwise
 151  */
 152 const struct thermal_trip *
 153 of_thermal_get_trip_points(struct thermal_zone_device *tz)
 154 {
 155         struct __thermal_zone *data = tz->devdata;
 156
 157         if (!data)
 158                 return NULL;
 159
 160         return data->trips;
 161 }
 162 EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);
 163
 164 /**
 165  * of_thermal_set_emul_temp - function to set emulated temperature
 166  *
 167  * @tz: pointer to a thermal zone
 168  * @temp:       temperature to set
 169  *
 170  * This function gives the ability to set emulated value of temperature,
 171  * which is handy for debugging
 172  *
 173  * Return: zero on success, error code otherwise
 174  */
 175 static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
 176                                     unsigned long temp)
 177 {
 178         struct __thermal_zone *data = tz->devdata;
 179
 180         if (!data->ops || !data->ops->set_emul_temp)
 181                 return -EINVAL;
 182
 183         return data->ops->set_emul_temp(data->sensor_data, temp);
 184 }
 185
 186 static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
 187                                 enum thermal_trend *trend)
 188 {
 189         struct __thermal_zone *data = tz->devdata;
 190         long dev_trend;
 191         int r;
 192
 193         if (!data->ops->get_trend)
 194                 return -EINVAL;
 195
 196         r = data->ops->get_trend(data->sensor_data, &dev_trend);
 197         if (r)
 198                 return r;
 199
 200         /* TODO: These intervals might have some thresholds, but in core code */
 201         if (dev_trend > 0)
 202                 *trend = THERMAL_TREND_RAISING;
 203         else if (dev_trend < 0)
 204                 *trend = THERMAL_TREND_DROPPING;
 205         else
 206                 *trend = THERMAL_TREND_STABLE;
 207
 208         return 0;
 209 }
 210
 211 static int of_thermal_bind(struct thermal_zone_device *thermal,
 212                            struct thermal_cooling_device *cdev)
 213 {
 214         struct __thermal_zone *data = thermal->devdata;
 215         int i;
 216
 217         if (!data || IS_ERR(data))
 218                 return -ENODEV;
 219
 220         /* find where to bind */
 221         for (i = 0; i < data->num_tbps; i++) {
 222                 struct __thermal_bind_params *tbp = data->tbps + i;
 223
 224                 if (tbp->cooling_device == cdev->np) {
 225                         int ret;
 226
 227                         ret = thermal_zone_bind_cooling_device(thermal,
 228                                                 tbp->trip_id, cdev,
 229                                                 tbp->max,
 230                                                 tbp->min,
 231                                                 tbp->usage);
 232                         if (ret)
 233                                 return ret;
 234                 }
 235         }
 236
 237         return 0;
 238 }
 239
 240 static int of_thermal_unbind(struct thermal_zone_device *thermal,
 241                              struct thermal_cooling_device *cdev)
 242 {
 243         struct __thermal_zone *data = thermal->devdata;
 244         int i;
 245
 246         if (!data || IS_ERR(data))
 247                 return -ENODEV;
 248
 249         /* find where to unbind */
 250         for (i = 0; i < data->num_tbps; i++) {
 251                 struct __thermal_bind_params *tbp = data->tbps + i;
 252
 253                 if (tbp->cooling_device == cdev->np) {
 254                         int ret;
 255
 256                         ret = thermal_zone_unbind_cooling_device(thermal,
 257                                                 tbp->trip_id, cdev);
 258                         if (ret)
 259                                 return ret;
 260                 }
 261         }
 262
 263         return 0;
 264 }
 265
 266 static int of_thermal_get_mode(struct thermal_zone_device *tz,
 267                                enum thermal_device_mode *mode)
 268 {
 269         struct __thermal_zone *data = tz->devdata;
 270
 271         *mode = data->mode;
 272
 273         return 0;
 274 }
 275
 276 static int of_thermal_set_mode(struct thermal_zone_device *tz,
 277                                enum thermal_device_mode mode)
 278 {
 279         struct __thermal_zone *data = tz->devdata;
 280
 281         mutex_lock(&tz->lock);
 282
 283         if (mode == THERMAL_DEVICE_ENABLED)
 284                 tz->polling_delay = data->polling_delay;
 285         else
 286                 tz->polling_delay = 0;
 287
 288         mutex_unlock(&tz->lock);
 289
 290         data->mode = mode;
 291         thermal_zone_device_update(tz);
 292
 293         return 0;
 294 }
 295
 296 static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
 297                                     enum thermal_trip_type *type)
 298 {
 299         struct __thermal_zone *data = tz->devdata;
 300
 301         if (trip >= data->ntrips || trip < 0)
 302                 return -EDOM;
 303
 304         *type = data->trips[trip].type;
 305
 306         return 0;
 307 }
 308
 309 static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
 310                                     unsigned long *temp)
 311 {
 312         struct __thermal_zone *data = tz->devdata;
 313
 314         if (trip >= data->ntrips || trip < 0)
 315                 return -EDOM;
 316
 317         *temp = data->trips[trip].temperature;
 318
 319         return 0;
 320 }
 321
 322 static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
 323                                     unsigned long temp)
 324 {
 325         struct __thermal_zone *data = tz->devdata;
 326
 327         if (trip >= data->ntrips || trip < 0)
 328                 return -EDOM;
 329
 330         /* thermal framework should take care of data->mask & (1 << trip) */
 331         data->trips[trip].temperature = temp;
 332
 333         return 0;
 334 }
 335
 336 static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
 337                                     unsigned long *hyst)
 338 {
 339         struct __thermal_zone *data = tz->devdata;
 340
 341         if (trip >= data->ntrips || trip < 0)
 342                 return -EDOM;
 343
 344         *hyst = data->trips[trip].hysteresis;
 345
 346         return 0;
 347 }
 348
 349 static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
 350                                     unsigned long hyst)
 351 {
 352         struct __thermal_zone *data = tz->devdata;
 353
 354         if (trip >= data->ntrips || trip < 0)
 355                 return -EDOM;
 356
 357         /* thermal framework should take care of data->mask & (1 << trip) */
 358         data->trips[trip].hysteresis = hyst;
 359
 360         return 0;
 361 }
 362
 363 static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
 364                                     unsigned long *temp)
 365 {
 366         struct __thermal_zone *data = tz->devdata;
 367         int i;
 368
 369         for (i = 0; i < data->ntrips; i++)
 370                 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
 371                         *temp = data->trips[i].temperature;
 372                         return 0;
 373                 }
 374
 375         return -EINVAL;
 376 }
 377
 378 static struct thermal_zone_device_ops of_thermal_ops = {
 379         .get_mode = of_thermal_get_mode,
 380         .set_mode = of_thermal_set_mode,
 381
 382         .get_trip_type = of_thermal_get_trip_type,
 383         .get_trip_temp = of_thermal_get_trip_temp,
 384         .set_trip_temp = of_thermal_set_trip_temp,
 385         .get_trip_hyst = of_thermal_get_trip_hyst,
 386         .set_trip_hyst = of_thermal_set_trip_hyst,
 387         .get_crit_temp = of_thermal_get_crit_temp,
 388
 389         .bind = of_thermal_bind,
 390         .unbind = of_thermal_unbind,
 391 };
 392
 393 /***   sensor API   ***/
 394
 395 static struct thermal_zone_device *
 396 thermal_zone_of_add_sensor(struct device_node *zone,
 397                            struct device_node *sensor, void *data,
 398                            const struct thermal_zone_of_device_ops *ops)
 399 {
 400         struct thermal_zone_device *tzd;
 401         struct __thermal_zone *tz;
 402
 403         tzd = thermal_zone_get_zone_by_name(zone->name);
 404         if (IS_ERR(tzd))
 405                 return ERR_PTR(-EPROBE_DEFER);
 406
 407         tz = tzd->devdata;
 408
 409         if (!ops)
 410                 return ERR_PTR(-EINVAL);
 411
 412         mutex_lock(&tzd->lock);
 413         tz->ops = ops;
 414         tz->sensor_data = data;
 415
 416         tzd->ops->get_temp = of_thermal_get_temp;
 417         tzd->ops->get_trend = of_thermal_get_trend;
 418         tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
 419         mutex_unlock(&tzd->lock);
 420
 421         return tzd;
 422 }
 423
 424 /**
 425  * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
 426  * @dev: a valid struct device pointer of a sensor device. Must contain
 427  *       a valid .of_node, for the sensor node.
 428  * @sensor_id: a sensor identifier, in case the sensor IP has more
 429  *             than one sensors
 430  * @data: a private pointer (owned by the caller) that will be passed
 431  *        back, when a temperature reading is needed.
 432  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 433  *
 434  * This function will search the list of thermal zones described in device
 435  * tree and look for the zone that refer to the sensor device pointed by
 436  * @dev->of_node as temperature providers. For the zone pointing to the
 437  * sensor node, the sensor will be added to the DT thermal zone device.
 438  *
 439  * The thermal zone temperature is provided by the @get_temp function
 440  * pointer. When called, it will have the private pointer @data back.
 441  *
 442  * The thermal zone temperature trend is provided by the @get_trend function
 443  * pointer. When called, it will have the private pointer @data back.
 444  *
 445  * TODO:
 446  * 01 - This function must enqueue the new sensor instead of using
 447  * it as the only source of temperature values.
 448  *
 449  * 02 - There must be a way to match the sensor with all thermal zones
 450  * that refer to it.
 451  *
 452  * Return: On success returns a valid struct thermal_zone_device,
 453  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 454  * check the return value with help of IS_ERR() helper.
 455  */
 456 struct thermal_zone_device *
 457 thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
 458                                 const struct thermal_zone_of_device_ops *ops)
 459 {
 460         struct device_node *np, *child, *sensor_np;
 461         struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
 462
 463         np = of_find_node_by_name(NULL, "thermal-zones");
 464         if (!np)
 465                 return ERR_PTR(-ENODEV);
 466
 467         if (!dev || !dev->of_node) {
 468                 of_node_put(np);
 469                 return ERR_PTR(-EINVAL);
 470         }
 471
 472         sensor_np = of_node_get(dev->of_node);
 473
 474         for_each_child_of_node(np, child) {
 475                 struct of_phandle_args sensor_specs;
 476                 int ret, id;
 477
 478                 /* Check whether child is enabled or not */
 479                 if (!of_device_is_available(child))
 480                         continue;
 481
 482                 /* For now, thermal framework supports only 1 sensor per zone */
 483                 ret = of_parse_phandle_with_args(child, "thermal-sensors",
 484                                                  "#thermal-sensor-cells",
 485                                                  0, &sensor_specs);
 486                 if (ret)
 487                         continue;
 488
 489                 if (sensor_specs.args_count >= 1) {
 490                         id = sensor_specs.args[0];
 491                         WARN(sensor_specs.args_count > 1,
 492                              "%s: too many cells in sensor specifier %d\n",
 493                              sensor_specs.np->name, sensor_specs.args_count);
 494                 } else {
 495                         id = 0;
 496                 }
 497
 498                 if (sensor_specs.np == sensor_np && id == sensor_id) {
 499                         tzd = thermal_zone_of_add_sensor(child, sensor_np,
 500                                                          data, ops);
 501                         if (!IS_ERR(tzd))
 502                                 tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED);
 503
 504                         of_node_put(sensor_specs.np);
 505                         of_node_put(child);
 506                         goto exit;
 507                 }
 508                 of_node_put(sensor_specs.np);
 509         }
 510 exit:
 511         of_node_put(sensor_np);
 512         of_node_put(np);
 513
 514         return tzd;
 515 }
 516 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
 517
 518 /**
 519  * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
 520  * @dev: a valid struct device pointer of a sensor device. Must contain
 521  *       a valid .of_node, for the sensor node.
 522  * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
 523  *
 524  * This function removes the sensor callbacks and private data from the
 525  * thermal zone device registered with thermal_zone_of_sensor_register()
 526  * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 527  * thermal zone device callbacks.
 528  *
 529  * TODO: When the support to several sensors per zone is added, this
 530  * function must search the sensor list based on @dev parameter.
 531  *
 532  */
 533 void thermal_zone_of_sensor_unregister(struct device *dev,
 534                                        struct thermal_zone_device *tzd)
 535 {
 536         struct __thermal_zone *tz;
 537
 538         if (!dev || !tzd || !tzd->devdata)
 539                 return;
 540
 541         tz = tzd->devdata;
 542
 543         /* no __thermal_zone, nothing to be done */
 544         if (!tz)
 545                 return;
 546
 547         mutex_lock(&tzd->lock);
 548         tzd->ops->get_temp = NULL;
 549         tzd->ops->get_trend = NULL;
 550         tzd->ops->set_emul_temp = NULL;
 551
 552         tz->ops = NULL;
 553         tz->sensor_data = NULL;
 554         mutex_unlock(&tzd->lock);
 555 }
 556 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
 557
 558 /***   functions parsing device tree nodes   ***/
 559
 560 /**
 561  * thermal_of_populate_bind_params - parse and fill cooling map data
 562  * @np: DT node containing a cooling-map node
 563  * @__tbp: data structure to be filled with cooling map info
 564  * @trips: array of thermal zone trip points
 565  * @ntrips: number of trip points inside trips.
 566  *
 567  * This function parses a cooling-map type of node represented by
 568  * @np parameter and fills the read data into @__tbp data structure.
 569  * It needs the already parsed array of trip points of the thermal zone
 570  * in consideration.
 571  *
 572  * Return: 0 on success, proper error code otherwise
 573  */
 574 static int thermal_of_populate_bind_params(struct device_node *np,
 575                                            struct __thermal_bind_params *__tbp,
 576                                            struct thermal_trip *trips,
 577                                            int ntrips)
 578 {
 579         struct of_phandle_args cooling_spec;
 580         struct device_node *trip;
 581         int ret, i;
 582         u32 prop;
 583
 584         /* Default weight. Usage is optional */
 585         __tbp->usage = THERMAL_WEIGHT_DEFAULT;
 586         ret = of_property_read_u32(np, "contribution", &prop);
 587         if (ret == 0)
 588                 __tbp->usage = prop;
 589
 590         trip = of_parse_phandle(np, "trip", 0);
 591         if (!trip) {
 592                 pr_err("missing trip property\n");
 593                 return -ENODEV;
 594         }
 595
 596         /* match using device_node */
 597         for (i = 0; i < ntrips; i++)
 598                 if (trip == trips[i].np) {
 599                         __tbp->trip_id = i;
 600                         break;
 601                 }
 602
 603         if (i == ntrips) {
 604                 ret = -ENODEV;
 605                 goto end;
 606         }
 607
 608         ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
 609                                          0, &cooling_spec);
 610         if (ret < 0) {
 611                 pr_err("missing cooling_device property\n");
 612                 goto end;
 613         }
 614         __tbp->cooling_device = cooling_spec.np;
 615         if (cooling_spec.args_count >= 2) { /* at least min and max */
 616                 __tbp->min = cooling_spec.args[0];
 617                 __tbp->max = cooling_spec.args[1];
 618         } else {
 619                 pr_err("wrong reference to cooling device, missing limits\n");
 620         }
 621
 622 end:
 623         of_node_put(trip);
 624
 625         return ret;
 626 }
 627
 628 /**
 629  * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
 630  * into the device tree binding of 'trip', property type.
 631  */
 632 static const char * const trip_types[] = {
 633         [THERMAL_TRIP_ACTIVE]   = "active",
 634         [THERMAL_TRIP_PASSIVE]  = "passive",
 635         [THERMAL_TRIP_HOT]      = "hot",
 636         [THERMAL_TRIP_CRITICAL] = "critical",
 637 };
 638
 639 /**
 640  * thermal_of_get_trip_type - Get phy mode for given device_node
 641  * @np: Pointer to the given device_node
 642  * @type: Pointer to resulting trip type
 643  *
 644  * The function gets trip type string from property 'type',
 645  * and store its index in trip_types table in @type,
 646  *
 647  * Return: 0 on success, or errno in error case.
 648  */
 649 static int thermal_of_get_trip_type(struct device_node *np,
 650                                     enum thermal_trip_type *type)
 651 {
 652         const char *t;
 653         int err, i;
 654
 655         err = of_property_read_string(np, "type", &t);
 656         if (err < 0)
 657                 return err;
 658
 659         for (i = 0; i < ARRAY_SIZE(trip_types); i++)
 660                 if (!strcasecmp(t, trip_types[i])) {
 661                         *type = i;
 662                         return 0;
 663                 }
 664
 665         return -ENODEV;
 666 }
 667
 668 /**
 669  * thermal_of_populate_trip - parse and fill one trip point data
 670  * @np: DT node containing a trip point node
 671  * @trip: trip point data structure to be filled up
 672  *
 673  * This function parses a trip point type of node represented by
 674  * @np parameter and fills the read data into @trip data structure.
 675  *
 676  * Return: 0 on success, proper error code otherwise
 677  */
 678 static int thermal_of_populate_trip(struct device_node *np,
 679                                     struct thermal_trip *trip)
 680 {
 681         int prop;
 682         int ret;
 683
 684         ret = of_property_read_u32(np, "temperature", &prop);
 685         if (ret < 0) {
 686                 pr_err("missing temperature property\n");
 687                 return ret;
 688         }
 689         trip->temperature = prop;
 690
 691         ret = of_property_read_u32(np, "hysteresis", &prop);
 692         if (ret < 0) {
 693                 pr_err("missing hysteresis property\n");
 694                 return ret;
 695         }
 696         trip->hysteresis = prop;
 697
 698         ret = thermal_of_get_trip_type(np, &trip->type);
 699         if (ret < 0) {
 700                 pr_err("wrong trip type property\n");
 701                 return ret;
 702         }
 703
 704         /* Required for cooling map matching */
 705         trip->np = np;
 706         of_node_get(np);
 707
 708         return 0;
 709 }
 710
 711 /**
 712  * thermal_of_build_thermal_zone - parse and fill one thermal zone data
 713  * @np: DT node containing a thermal zone node
 714  *
 715  * This function parses a thermal zone type of node represented by
 716  * @np parameter and fills the read data into a __thermal_zone data structure
 717  * and return this pointer.
 718  *
 719  * TODO: Missing properties to parse: thermal-sensor-names and coefficients
 720  *
 721  * Return: On success returns a valid struct __thermal_zone,
 722  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 723  * check the return value with help of IS_ERR() helper.
 724  */
 725 static struct __thermal_zone *
 726 thermal_of_build_thermal_zone(struct device_node *np)
 727 {
 728         struct device_node *child = NULL, *gchild;
 729         struct __thermal_zone *tz;
 730         int ret, i;
 731         u32 prop;
 732
 733         if (!np) {
 734                 pr_err("no thermal zone np\n");
 735                 return ERR_PTR(-EINVAL);
 736         }
 737
 738         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
 739         if (!tz)
 740                 return ERR_PTR(-ENOMEM);
 741
 742         ret = of_property_read_u32(np, "polling-delay-passive", &prop);
 743         if (ret < 0) {
 744                 pr_err("missing polling-delay-passive property\n");
 745                 goto free_tz;
 746         }
 747         tz->passive_delay = prop;
 748
 749         ret = of_property_read_u32(np, "polling-delay", &prop);
 750         if (ret < 0) {
 751                 pr_err("missing polling-delay property\n");
 752                 goto free_tz;
 753         }
 754         tz->polling_delay = prop;
 755
 756         /* trips */
 757         child = of_get_child_by_name(np, "trips");
 758
 759         /* No trips provided */
 760         if (!child)
 761                 goto finish;
 762
 763         tz->ntrips = of_get_child_count(child);
 764         if (tz->ntrips == 0) /* must have at least one child */
 765                 goto finish;
 766
 767         tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
 768         if (!tz->trips) {
 769                 ret = -ENOMEM;
 770                 goto free_tz;
 771         }
 772
 773         i = 0;
 774         for_each_child_of_node(child, gchild) {
 775                 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
 776                 if (ret)
 777                         goto free_trips;
 778         }
 779
 780         of_node_put(child);
 781
 782         /* cooling-maps */
 783         child = of_get_child_by_name(np, "cooling-maps");
 784
 785         /* cooling-maps not provided */
 786         if (!child)
 787                 goto finish;
 788
 789         tz->num_tbps = of_get_child_count(child);
 790         if (tz->num_tbps == 0)
 791                 goto finish;
 792
 793         tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
 794         if (!tz->tbps) {
 795                 ret = -ENOMEM;
 796                 goto free_trips;
 797         }
 798
 799         i = 0;
 800         for_each_child_of_node(child, gchild) {
 801                 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
 802                                                       tz->trips, tz->ntrips);
 803                 if (ret)
 804                         goto free_tbps;
 805         }
 806
 807 finish:
 808         of_node_put(child);
 809         tz->mode = THERMAL_DEVICE_DISABLED;
 810
 811         return tz;
 812
 813 free_tbps:
 814         for (i = 0; i < tz->num_tbps; i++)
 815                 of_node_put(tz->tbps[i].cooling_device);
 816         kfree(tz->tbps);
 817 free_trips:
 818         for (i = 0; i < tz->ntrips; i++)
 819                 of_node_put(tz->trips[i].np);
 820         kfree(tz->trips);
 821         of_node_put(gchild);
 822 free_tz:
 823         kfree(tz);
 824         of_node_put(child);
 825
 826         return ERR_PTR(ret);
 827 }
 828
 829 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
 830 {
 831         int i;
 832
 833         for (i = 0; i < tz->num_tbps; i++)
 834                 of_node_put(tz->tbps[i].cooling_device);
 835         kfree(tz->tbps);
 836         for (i = 0; i < tz->ntrips; i++)
 837                 of_node_put(tz->trips[i].np);
 838         kfree(tz->trips);
 839         kfree(tz);
 840 }
 841
 842 /**
 843  * of_parse_thermal_zones - parse device tree thermal data
 844  *
 845  * Initialization function that can be called by machine initialization
 846  * code to parse thermal data and populate the thermal framework
 847  * with hardware thermal zones info. This function only parses thermal zones.
 848  * Cooling devices and sensor devices nodes are supposed to be parsed
 849  * by their respective drivers.
 850  *
 851  * Return: 0 on success, proper error code otherwise
 852  *
 853  */
 854 int __init of_parse_thermal_zones(void)
 855 {
 856         struct device_node *np, *child;
 857         struct __thermal_zone *tz;
 858         struct thermal_zone_device_ops *ops;
 859
 860         np = of_find_node_by_name(NULL, "thermal-zones");
 861         if (!np) {
 862                 pr_debug("unable to find thermal zones\n");
 863                 return 0; /* Run successfully on systems without thermal DT */
 864         }
 865
 866         for_each_child_of_node(np, child) {
 867                 struct thermal_zone_device *zone;
 868                 struct thermal_zone_params *tzp;
 869
 870                 /* Check whether child is enabled or not */
 871                 if (!of_device_is_available(child))
 872                         continue;
 873
 874                 tz = thermal_of_build_thermal_zone(child);
 875                 if (IS_ERR(tz)) {
 876                         pr_err("failed to build thermal zone %s: %ld\n",
 877                                child->name,
 878                                PTR_ERR(tz));
 879                         continue;
 880                 }
 881
 882                 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
 883                 if (!ops)
 884                         goto exit_free;
 885
 886                 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
 887                 if (!tzp) {
 888                         kfree(ops);
 889                         goto exit_free;
 890                 }
 891
 892                 /* No hwmon because there might be hwmon drivers registering */
 893                 tzp->no_hwmon = true;
 894
 895                 zone = thermal_zone_device_register(child->name, tz->ntrips,
 896                                                     0, tz,
 897                                                     ops, tzp,
 898                                                     tz->passive_delay,
 899                                                     tz->polling_delay);
 900                 if (IS_ERR(zone)) {
 901                         pr_err("Failed to build %s zone %ld\n", child->name,
 902                                PTR_ERR(zone));
 903                         kfree(tzp);
 904                         kfree(ops);
 905                         of_thermal_free_zone(tz);
 906                         /* attempting to build remaining zones still */
 907                 }
 908         }
 909         of_node_put(np);
 910
 911         return 0;
 912
 913 exit_free:
 914         of_node_put(child);
 915         of_node_put(np);
 916         of_thermal_free_zone(tz);
 917
 918         /* no memory available, so free what we have built */
 919         of_thermal_destroy_zones();
 920
 921         return -ENOMEM;
 922 }
 923
 924 /**
 925  * of_thermal_destroy_zones - remove all zones parsed and allocated resources
 926  *
 927  * Finds all zones parsed and added to the thermal framework and remove them
 928  * from the system, together with their resources.
 929  *
 930  */
 931 void of_thermal_destroy_zones(void)
 932 {
 933         struct device_node *np, *child;
 934
 935         np = of_find_node_by_name(NULL, "thermal-zones");
 936         if (!np) {
 937                 pr_err("unable to find thermal zones\n");
 938                 return;
 939         }
 940
 941         for_each_child_of_node(np, child) {
 942                 struct thermal_zone_device *zone;
 943
 944                 /* Check whether child is enabled or not */
 945                 if (!of_device_is_available(child))
 946                         continue;
 947
 948                 zone = thermal_zone_get_zone_by_name(child->name);
 949                 if (IS_ERR(zone))
 950                         continue;
 951
 952                 thermal_zone_device_unregister(zone);
 953                 kfree(zone->tzp);
 954                 kfree(zone->ops);
 955                 of_thermal_free_zone(zone->devdata);
 956         }
 957         of_node_put(np);
 958 }