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  * @slope: slope of the temperature adjustment curve
  62  * @offset: offset of the temperature adjustment curve
  63  * @ntrips: number of trip points
  64  * @trips: an array of trip points (0..ntrips - 1)
  65  * @num_tbps: number of thermal bind params
  66  * @tbps: an array of thermal bind params (0..num_tbps - 1)
  67  * @sensor_data: sensor private data used while reading temperature and trend
  68  * @ops: set of callbacks to handle the thermal zone based on DT
  69  */
  70
  71 struct __thermal_zone {
  72         enum thermal_device_mode mode;
  73         int passive_delay;
  74         int polling_delay;
  75         int slope;
  76         int offset;
  77
  78         /* trip data */
  79         int ntrips;
  80         struct thermal_trip *trips;
  81
  82         /* cooling binding data */
  83         int num_tbps;
  84         struct __thermal_bind_params *tbps;
  85
  86         /* sensor interface */
  87         void *sensor_data;
  88         const struct thermal_zone_of_device_ops *ops;
  89 };
  90
  91 /***   DT thermal zone device callbacks   ***/
  92
  93 static int of_thermal_get_temp(struct thermal_zone_device *tz,
  94                                int *temp)
  95 {
  96         struct __thermal_zone *data = tz->devdata;
  97
  98         if (!data->ops->get_temp)
  99                 return -EINVAL;
 100
 101         return data->ops->get_temp(data->sensor_data, temp);
 102 }
 103
 104 /**
 105  * of_thermal_get_ntrips - function to export number of available trip
 106  *                         points.
 107  * @tz: pointer to a thermal zone
 108  *
 109  * This function is a globally visible wrapper to get number of trip points
 110  * stored in the local struct __thermal_zone
 111  *
 112  * Return: number of available trip points, -ENODEV when data not available
 113  */
 114 int of_thermal_get_ntrips(struct thermal_zone_device *tz)
 115 {
 116         struct __thermal_zone *data = tz->devdata;
 117
 118         if (!data || IS_ERR(data))
 119                 return -ENODEV;
 120
 121         return data->ntrips;
 122 }
 123 EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);
 124
 125 /**
 126  * of_thermal_is_trip_valid - function to check if trip point is valid
 127  *
 128  * @tz: pointer to a thermal zone
 129  * @trip:       trip point to evaluate
 130  *
 131  * This function is responsible for checking if passed trip point is valid
 132  *
 133  * Return: true if trip point is valid, false otherwise
 134  */
 135 bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
 136 {
 137         struct __thermal_zone *data = tz->devdata;
 138
 139         if (!data || trip >= data->ntrips || trip < 0)
 140                 return false;
 141
 142         return true;
 143 }
 144 EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);
 145
 146 /**
 147  * of_thermal_get_trip_points - function to get access to a globally exported
 148  *                              trip points
 149  *
 150  * @tz: pointer to a thermal zone
 151  *
 152  * This function provides a pointer to trip points table
 153  *
 154  * Return: pointer to trip points table, NULL otherwise
 155  */
 156 const struct thermal_trip *
 157 of_thermal_get_trip_points(struct thermal_zone_device *tz)
 158 {
 159         struct __thermal_zone *data = tz->devdata;
 160
 161         if (!data)
 162                 return NULL;
 163
 164         return data->trips;
 165 }
 166 EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);
 167
 168 /**
 169  * of_thermal_set_emul_temp - function to set emulated temperature
 170  *
 171  * @tz: pointer to a thermal zone
 172  * @temp:       temperature to set
 173  *
 174  * This function gives the ability to set emulated value of temperature,
 175  * which is handy for debugging
 176  *
 177  * Return: zero on success, error code otherwise
 178  */
 179 static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
 180                                     int temp)
 181 {
 182         struct __thermal_zone *data = tz->devdata;
 183
 184         if (!data->ops || !data->ops->set_emul_temp)
 185                 return -EINVAL;
 186
 187         return data->ops->set_emul_temp(data->sensor_data, temp);
 188 }
 189
 190 static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
 191                                 enum thermal_trend *trend)
 192 {
 193         struct __thermal_zone *data = tz->devdata;
 194         long dev_trend;
 195         int r;
 196
 197         if (!data->ops->get_trend)
 198                 return -EINVAL;
 199
 200         r = data->ops->get_trend(data->sensor_data, &dev_trend);
 201         if (r)
 202                 return r;
 203
 204         /* TODO: These intervals might have some thresholds, but in core code */
 205         if (dev_trend > 0)
 206                 *trend = THERMAL_TREND_RAISING;
 207         else if (dev_trend < 0)
 208                 *trend = THERMAL_TREND_DROPPING;
 209         else
 210                 *trend = THERMAL_TREND_STABLE;
 211
 212         return 0;
 213 }
 214
 215 static int of_thermal_bind(struct thermal_zone_device *thermal,
 216                            struct thermal_cooling_device *cdev)
 217 {
 218         struct __thermal_zone *data = thermal->devdata;
 219         int i;
 220
 221         if (!data || IS_ERR(data))
 222                 return -ENODEV;
 223
 224         /* find where to bind */
 225         for (i = 0; i < data->num_tbps; i++) {
 226                 struct __thermal_bind_params *tbp = data->tbps + i;
 227
 228                 if (tbp->cooling_device == cdev->np) {
 229                         int ret;
 230
 231                         ret = thermal_zone_bind_cooling_device(thermal,
 232                                                 tbp->trip_id, cdev,
 233                                                 tbp->max,
 234                                                 tbp->min,
 235                                                 tbp->usage);
 236                         if (ret)
 237                                 return ret;
 238                 }
 239         }
 240
 241         return 0;
 242 }
 243
 244 static int of_thermal_unbind(struct thermal_zone_device *thermal,
 245                              struct thermal_cooling_device *cdev)
 246 {
 247         struct __thermal_zone *data = thermal->devdata;
 248         int i;
 249
 250         if (!data || IS_ERR(data))
 251                 return -ENODEV;
 252
 253         /* find where to unbind */
 254         for (i = 0; i < data->num_tbps; i++) {
 255                 struct __thermal_bind_params *tbp = data->tbps + i;
 256
 257                 if (tbp->cooling_device == cdev->np) {
 258                         int ret;
 259
 260                         ret = thermal_zone_unbind_cooling_device(thermal,
 261                                                 tbp->trip_id, cdev);
 262                         if (ret)
 263                                 return ret;
 264                 }
 265         }
 266
 267         return 0;
 268 }
 269
 270 static int of_thermal_get_mode(struct thermal_zone_device *tz,
 271                                enum thermal_device_mode *mode)
 272 {
 273         struct __thermal_zone *data = tz->devdata;
 274
 275         *mode = data->mode;
 276
 277         return 0;
 278 }
 279
 280 static int of_thermal_set_mode(struct thermal_zone_device *tz,
 281                                enum thermal_device_mode mode)
 282 {
 283         struct __thermal_zone *data = tz->devdata;
 284
 285         mutex_lock(&tz->lock);
 286
 287         if (mode == THERMAL_DEVICE_ENABLED)
 288                 tz->polling_delay = data->polling_delay;
 289         else
 290                 tz->polling_delay = 0;
 291
 292         mutex_unlock(&tz->lock);
 293
 294         data->mode = mode;
 295         thermal_zone_device_update(tz);
 296
 297         return 0;
 298 }
 299
 300 static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
 301                                     enum thermal_trip_type *type)
 302 {
 303         struct __thermal_zone *data = tz->devdata;
 304
 305         if (trip >= data->ntrips || trip < 0)
 306                 return -EDOM;
 307
 308         *type = data->trips[trip].type;
 309
 310         return 0;
 311 }
 312
 313 static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
 314                                     int *temp)
 315 {
 316         struct __thermal_zone *data = tz->devdata;
 317
 318         if (trip >= data->ntrips || trip < 0)
 319                 return -EDOM;
 320
 321         *temp = data->trips[trip].temperature;
 322
 323         return 0;
 324 }
 325
 326 static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
 327                                     int temp)
 328 {
 329         struct __thermal_zone *data = tz->devdata;
 330
 331         if (trip >= data->ntrips || trip < 0)
 332                 return -EDOM;
 333
 334         /* thermal framework should take care of data->mask & (1 << trip) */
 335         data->trips[trip].temperature = temp;
 336
 337         return 0;
 338 }
 339
 340 static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
 341                                     int *hyst)
 342 {
 343         struct __thermal_zone *data = tz->devdata;
 344
 345         if (trip >= data->ntrips || trip < 0)
 346                 return -EDOM;
 347
 348         *hyst = data->trips[trip].hysteresis;
 349
 350         return 0;
 351 }
 352
 353 static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
 354                                     int hyst)
 355 {
 356         struct __thermal_zone *data = tz->devdata;
 357
 358         if (trip >= data->ntrips || trip < 0)
 359                 return -EDOM;
 360
 361         /* thermal framework should take care of data->mask & (1 << trip) */
 362         data->trips[trip].hysteresis = hyst;
 363
 364         return 0;
 365 }
 366
 367 static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
 368                                     int *temp)
 369 {
 370         struct __thermal_zone *data = tz->devdata;
 371         int i;
 372
 373         for (i = 0; i < data->ntrips; i++)
 374                 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
 375                         *temp = data->trips[i].temperature;
 376                         return 0;
 377                 }
 378
 379         return -EINVAL;
 380 }
 381
 382 static struct thermal_zone_device_ops of_thermal_ops = {
 383         .get_mode = of_thermal_get_mode,
 384         .set_mode = of_thermal_set_mode,
 385
 386         .get_trip_type = of_thermal_get_trip_type,
 387         .get_trip_temp = of_thermal_get_trip_temp,
 388         .set_trip_temp = of_thermal_set_trip_temp,
 389         .get_trip_hyst = of_thermal_get_trip_hyst,
 390         .set_trip_hyst = of_thermal_set_trip_hyst,
 391         .get_crit_temp = of_thermal_get_crit_temp,
 392
 393         .bind = of_thermal_bind,
 394         .unbind = of_thermal_unbind,
 395 };
 396
 397 /***   sensor API   ***/
 398
 399 static struct thermal_zone_device *
 400 thermal_zone_of_add_sensor(struct device_node *zone,
 401                            struct device_node *sensor, void *data,
 402                            const struct thermal_zone_of_device_ops *ops)
 403 {
 404         struct thermal_zone_device *tzd;
 405         struct __thermal_zone *tz;
 406
 407         tzd = thermal_zone_get_zone_by_name(zone->name);
 408         if (IS_ERR(tzd))
 409                 return ERR_PTR(-EPROBE_DEFER);
 410
 411         tz = tzd->devdata;
 412
 413         if (!ops)
 414                 return ERR_PTR(-EINVAL);
 415
 416         mutex_lock(&tzd->lock);
 417         tz->ops = ops;
 418         tz->sensor_data = data;
 419
 420         tzd->ops->get_temp = of_thermal_get_temp;
 421         tzd->ops->get_trend = of_thermal_get_trend;
 422         tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
 423         mutex_unlock(&tzd->lock);
 424
 425         return tzd;
 426 }
 427
 428 /**
 429  * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
 430  * @dev: a valid struct device pointer of a sensor device. Must contain
 431  *       a valid .of_node, for the sensor node.
 432  * @sensor_id: a sensor identifier, in case the sensor IP has more
 433  *             than one sensors
 434  * @data: a private pointer (owned by the caller) that will be passed
 435  *        back, when a temperature reading is needed.
 436  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 437  *
 438  * This function will search the list of thermal zones described in device
 439  * tree and look for the zone that refer to the sensor device pointed by
 440  * @dev->of_node as temperature providers. For the zone pointing to the
 441  * sensor node, the sensor will be added to the DT thermal zone device.
 442  *
 443  * The thermal zone temperature is provided by the @get_temp function
 444  * pointer. When called, it will have the private pointer @data back.
 445  *
 446  * The thermal zone temperature trend is provided by the @get_trend function
 447  * pointer. When called, it will have the private pointer @data back.
 448  *
 449  * TODO:
 450  * 01 - This function must enqueue the new sensor instead of using
 451  * it as the only source of temperature values.
 452  *
 453  * 02 - There must be a way to match the sensor with all thermal zones
 454  * that refer to it.
 455  *
 456  * Return: On success returns a valid struct thermal_zone_device,
 457  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 458  * check the return value with help of IS_ERR() helper.
 459  */
 460 struct thermal_zone_device *
 461 thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
 462                                 const struct thermal_zone_of_device_ops *ops)
 463 {
 464         struct device_node *np, *child, *sensor_np;
 465         struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
 466
 467         np = of_find_node_by_name(NULL, "thermal-zones");
 468         if (!np)
 469                 return ERR_PTR(-ENODEV);
 470
 471         if (!dev || !dev->of_node) {
 472                 of_node_put(np);
 473                 return ERR_PTR(-EINVAL);
 474         }
 475
 476         sensor_np = of_node_get(dev->of_node);
 477
 478         for_each_available_child_of_node(np, child) {
 479                 struct of_phandle_args sensor_specs;
 480                 int ret, id;
 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 static void devm_thermal_zone_of_sensor_release(struct device *dev, void *res)
 559 {
 560         thermal_zone_of_sensor_unregister(dev,
 561                                           *(struct thermal_zone_device **)res);
 562 }
 563
 564 static int devm_thermal_zone_of_sensor_match(struct device *dev, void *res,
 565                                              void *data)
 566 {
 567         struct thermal_zone_device **r = res;
 568
 569         if (WARN_ON(!r || !*r))
 570                 return 0;
 571
 572         return *r == data;
 573 }
 574
 575 /**
 576  * devm_thermal_zone_of_sensor_register - Resource managed version of
 577  *                              thermal_zone_of_sensor_register()
 578  * @dev: a valid struct device pointer of a sensor device. Must contain
 579  *       a valid .of_node, for the sensor node.
 580  * @sensor_id: a sensor identifier, in case the sensor IP has more
 581  *             than one sensors
 582  * @data: a private pointer (owned by the caller) that will be passed
 583  *        back, when a temperature reading is needed.
 584  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 585  *
 586  * Refer thermal_zone_of_sensor_register() for more details.
 587  *
 588  * Return: On success returns a valid struct thermal_zone_device,
 589  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 590  * check the return value with help of IS_ERR() helper.
 591  * Registered hermal_zone_device device will automatically be
 592  * released when device is unbounded.
 593  */
 594 struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
 595         struct device *dev, int sensor_id,
 596         void *data, const struct thermal_zone_of_device_ops *ops)
 597 {
 598         struct thermal_zone_device **ptr, *tzd;
 599
 600         ptr = devres_alloc(devm_thermal_zone_of_sensor_release, sizeof(*ptr),
 601                            GFP_KERNEL);
 602         if (!ptr)
 603                 return ERR_PTR(-ENOMEM);
 604
 605         tzd = thermal_zone_of_sensor_register(dev, sensor_id, data, ops);
 606         if (IS_ERR(tzd)) {
 607                 devres_free(ptr);
 608                 return tzd;
 609         }
 610
 611         *ptr = tzd;
 612         devres_add(dev, ptr);
 613
 614         return tzd;
 615 }
 616 EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_register);
 617
 618 /**
 619  * devm_thermal_zone_of_sensor_unregister - Resource managed version of
 620  *                              thermal_zone_of_sensor_unregister().
 621  * @dev: Device for which which resource was allocated.
 622  * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
 623  *
 624  * This function removes the sensor callbacks and private data from the
 625  * thermal zone device registered with devm_thermal_zone_of_sensor_register()
 626  * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 627  * thermal zone device callbacks.
 628  * Normally this function will not need to be called and the resource
 629  * management code will ensure that the resource is freed.
 630  */
 631 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
 632                                             struct thermal_zone_device *tzd)
 633 {
 634         WARN_ON(devres_release(dev, devm_thermal_zone_of_sensor_release,
 635                                devm_thermal_zone_of_sensor_match, tzd));
 636 }
 637 EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
 638
 639 /***   functions parsing device tree nodes   ***/
 640
 641 /**
 642  * thermal_of_populate_bind_params - parse and fill cooling map data
 643  * @np: DT node containing a cooling-map node
 644  * @__tbp: data structure to be filled with cooling map info
 645  * @trips: array of thermal zone trip points
 646  * @ntrips: number of trip points inside trips.
 647  *
 648  * This function parses a cooling-map type of node represented by
 649  * @np parameter and fills the read data into @__tbp data structure.
 650  * It needs the already parsed array of trip points of the thermal zone
 651  * in consideration.
 652  *
 653  * Return: 0 on success, proper error code otherwise
 654  */
 655 static int thermal_of_populate_bind_params(struct device_node *np,
 656                                            struct __thermal_bind_params *__tbp,
 657                                            struct thermal_trip *trips,
 658                                            int ntrips)
 659 {
 660         struct of_phandle_args cooling_spec;
 661         struct device_node *trip;
 662         int ret, i;
 663         u32 prop;
 664
 665         /* Default weight. Usage is optional */
 666         __tbp->usage = THERMAL_WEIGHT_DEFAULT;
 667         ret = of_property_read_u32(np, "contribution", &prop);
 668         if (ret == 0)
 669                 __tbp->usage = prop;
 670
 671         trip = of_parse_phandle(np, "trip", 0);
 672         if (!trip) {
 673                 pr_err("missing trip property\n");
 674                 return -ENODEV;
 675         }
 676
 677         /* match using device_node */
 678         for (i = 0; i < ntrips; i++)
 679                 if (trip == trips[i].np) {
 680                         __tbp->trip_id = i;
 681                         break;
 682                 }
 683
 684         if (i == ntrips) {
 685                 ret = -ENODEV;
 686                 goto end;
 687         }
 688
 689         ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
 690                                          0, &cooling_spec);
 691         if (ret < 0) {
 692                 pr_err("missing cooling_device property\n");
 693                 goto end;
 694         }
 695         __tbp->cooling_device = cooling_spec.np;
 696         if (cooling_spec.args_count >= 2) { /* at least min and max */
 697                 __tbp->min = cooling_spec.args[0];
 698                 __tbp->max = cooling_spec.args[1];
 699         } else {
 700                 pr_err("wrong reference to cooling device, missing limits\n");
 701         }
 702
 703 end:
 704         of_node_put(trip);
 705
 706         return ret;
 707 }
 708
 709 /**
 710  * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
 711  * into the device tree binding of 'trip', property type.
 712  */
 713 static const char * const trip_types[] = {
 714         [THERMAL_TRIP_ACTIVE]   = "active",
 715         [THERMAL_TRIP_PASSIVE]  = "passive",
 716         [THERMAL_TRIP_HOT]      = "hot",
 717         [THERMAL_TRIP_CRITICAL] = "critical",
 718 };
 719
 720 /**
 721  * thermal_of_get_trip_type - Get phy mode for given device_node
 722  * @np: Pointer to the given device_node
 723  * @type: Pointer to resulting trip type
 724  *
 725  * The function gets trip type string from property 'type',
 726  * and store its index in trip_types table in @type,
 727  *
 728  * Return: 0 on success, or errno in error case.
 729  */
 730 static int thermal_of_get_trip_type(struct device_node *np,
 731                                     enum thermal_trip_type *type)
 732 {
 733         const char *t;
 734         int err, i;
 735
 736         err = of_property_read_string(np, "type", &t);
 737         if (err < 0)
 738                 return err;
 739
 740         for (i = 0; i < ARRAY_SIZE(trip_types); i++)
 741                 if (!strcasecmp(t, trip_types[i])) {
 742                         *type = i;
 743                         return 0;
 744                 }
 745
 746         return -ENODEV;
 747 }
 748
 749 /**
 750  * thermal_of_populate_trip - parse and fill one trip point data
 751  * @np: DT node containing a trip point node
 752  * @trip: trip point data structure to be filled up
 753  *
 754  * This function parses a trip point type of node represented by
 755  * @np parameter and fills the read data into @trip data structure.
 756  *
 757  * Return: 0 on success, proper error code otherwise
 758  */
 759 static int thermal_of_populate_trip(struct device_node *np,
 760                                     struct thermal_trip *trip)
 761 {
 762         int prop;
 763         int ret;
 764
 765         ret = of_property_read_u32(np, "temperature", &prop);
 766         if (ret < 0) {
 767                 pr_err("missing temperature property\n");
 768                 return ret;
 769         }
 770         trip->temperature = prop;
 771
 772         ret = of_property_read_u32(np, "hysteresis", &prop);
 773         if (ret < 0) {
 774                 pr_err("missing hysteresis property\n");
 775                 return ret;
 776         }
 777         trip->hysteresis = prop;
 778
 779         ret = thermal_of_get_trip_type(np, &trip->type);
 780         if (ret < 0) {
 781                 pr_err("wrong trip type property\n");
 782                 return ret;
 783         }
 784
 785         /* Required for cooling map matching */
 786         trip->np = np;
 787         of_node_get(np);
 788
 789         return 0;
 790 }
 791
 792 /**
 793  * thermal_of_build_thermal_zone - parse and fill one thermal zone data
 794  * @np: DT node containing a thermal zone node
 795  *
 796  * This function parses a thermal zone type of node represented by
 797  * @np parameter and fills the read data into a __thermal_zone data structure
 798  * and return this pointer.
 799  *
 800  * TODO: Missing properties to parse: thermal-sensor-names
 801  *
 802  * Return: On success returns a valid struct __thermal_zone,
 803  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 804  * check the return value with help of IS_ERR() helper.
 805  */
 806 static struct __thermal_zone
 807 __init *thermal_of_build_thermal_zone(struct device_node *np)
 808 {
 809         struct device_node *child = NULL, *gchild;
 810         struct __thermal_zone *tz;
 811         int ret, i;
 812         u32 prop, coef[2];
 813
 814         if (!np) {
 815                 pr_err("no thermal zone np\n");
 816                 return ERR_PTR(-EINVAL);
 817         }
 818
 819         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
 820         if (!tz)
 821                 return ERR_PTR(-ENOMEM);
 822
 823         ret = of_property_read_u32(np, "polling-delay-passive", &prop);
 824         if (ret < 0) {
 825                 pr_err("missing polling-delay-passive property\n");
 826                 goto free_tz;
 827         }
 828         tz->passive_delay = prop;
 829
 830         ret = of_property_read_u32(np, "polling-delay", &prop);
 831         if (ret < 0) {
 832                 pr_err("missing polling-delay property\n");
 833                 goto free_tz;
 834         }
 835         tz->polling_delay = prop;
 836
 837         /*
 838          * REVIST: for now, the thermal framework supports only
 839          * one sensor per thermal zone. Thus, we are considering
 840          * only the first two values as slope and offset.
 841          */
 842         ret = of_property_read_u32_array(np, "coefficients", coef, 2);
 843         if (ret == 0) {
 844                 tz->slope = coef[0];
 845                 tz->offset = coef[1];
 846         } else {
 847                 tz->slope = 1;
 848                 tz->offset = 0;
 849         }
 850
 851         /* trips */
 852         child = of_get_child_by_name(np, "trips");
 853
 854         /* No trips provided */
 855         if (!child)
 856                 goto finish;
 857
 858         tz->ntrips = of_get_child_count(child);
 859         if (tz->ntrips == 0) /* must have at least one child */
 860                 goto finish;
 861
 862         tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
 863         if (!tz->trips) {
 864                 ret = -ENOMEM;
 865                 goto free_tz;
 866         }
 867
 868         i = 0;
 869         for_each_child_of_node(child, gchild) {
 870                 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
 871                 if (ret)
 872                         goto free_trips;
 873         }
 874
 875         of_node_put(child);
 876
 877         /* cooling-maps */
 878         child = of_get_child_by_name(np, "cooling-maps");
 879
 880         /* cooling-maps not provided */
 881         if (!child)
 882                 goto finish;
 883
 884         tz->num_tbps = of_get_child_count(child);
 885         if (tz->num_tbps == 0)
 886                 goto finish;
 887
 888         tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
 889         if (!tz->tbps) {
 890                 ret = -ENOMEM;
 891                 goto free_trips;
 892         }
 893
 894         i = 0;
 895         for_each_child_of_node(child, gchild) {
 896                 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
 897                                                       tz->trips, tz->ntrips);
 898                 if (ret)
 899                         goto free_tbps;
 900         }
 901
 902 finish:
 903         of_node_put(child);
 904         tz->mode = THERMAL_DEVICE_DISABLED;
 905
 906         return tz;
 907
 908 free_tbps:
 909         for (i = 0; i < tz->num_tbps; i++)
 910                 of_node_put(tz->tbps[i].cooling_device);
 911         kfree(tz->tbps);
 912 free_trips:
 913         for (i = 0; i < tz->ntrips; i++)
 914                 of_node_put(tz->trips[i].np);
 915         kfree(tz->trips);
 916         of_node_put(gchild);
 917 free_tz:
 918         kfree(tz);
 919         of_node_put(child);
 920
 921         return ERR_PTR(ret);
 922 }
 923
 924 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
 925 {
 926         int i;
 927
 928         for (i = 0; i < tz->num_tbps; i++)
 929                 of_node_put(tz->tbps[i].cooling_device);
 930         kfree(tz->tbps);
 931         for (i = 0; i < tz->ntrips; i++)
 932                 of_node_put(tz->trips[i].np);
 933         kfree(tz->trips);
 934         kfree(tz);
 935 }
 936
 937 /**
 938  * of_parse_thermal_zones - parse device tree thermal data
 939  *
 940  * Initialization function that can be called by machine initialization
 941  * code to parse thermal data and populate the thermal framework
 942  * with hardware thermal zones info. This function only parses thermal zones.
 943  * Cooling devices and sensor devices nodes are supposed to be parsed
 944  * by their respective drivers.
 945  *
 946  * Return: 0 on success, proper error code otherwise
 947  *
 948  */
 949 int __init of_parse_thermal_zones(void)
 950 {
 951         struct device_node *np, *child;
 952         struct __thermal_zone *tz;
 953         struct thermal_zone_device_ops *ops;
 954
 955         np = of_find_node_by_name(NULL, "thermal-zones");
 956         if (!np) {
 957                 pr_debug("unable to find thermal zones\n");
 958                 return 0; /* Run successfully on systems without thermal DT */
 959         }
 960
 961         for_each_available_child_of_node(np, child) {
 962                 struct thermal_zone_device *zone;
 963                 struct thermal_zone_params *tzp;
 964                 int i, mask = 0;
 965                 u32 prop;
 966
 967                 tz = thermal_of_build_thermal_zone(child);
 968                 if (IS_ERR(tz)) {
 969                         pr_err("failed to build thermal zone %s: %ld\n",
 970                                child->name,
 971                                PTR_ERR(tz));
 972                         continue;
 973                 }
 974
 975                 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
 976                 if (!ops)
 977                         goto exit_free;
 978
 979                 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
 980                 if (!tzp) {
 981                         kfree(ops);
 982                         goto exit_free;
 983                 }
 984
 985                 /* No hwmon because there might be hwmon drivers registering */
 986                 tzp->no_hwmon = true;
 987
 988                 if (!of_property_read_u32(child, "sustainable-power", &prop))
 989                         tzp->sustainable_power = prop;
 990
 991                 for (i = 0; i < tz->ntrips; i++)
 992                         mask |= 1 << i;
 993
 994                 /* these two are left for temperature drivers to use */
 995                 tzp->slope = tz->slope;
 996                 tzp->offset = tz->offset;
 997
 998                 zone = thermal_zone_device_register(child->name, tz->ntrips,
 999                                                     mask, tz,
1000                                                     ops, tzp,
1001                                                     tz->passive_delay,
1002                                                     tz->polling_delay);
1003                 if (IS_ERR(zone)) {
1004                         pr_err("Failed to build %s zone %ld\n", child->name,
1005                                PTR_ERR(zone));
1006                         kfree(tzp);
1007                         kfree(ops);
1008                         of_thermal_free_zone(tz);
1009                         /* attempting to build remaining zones still */
1010                 }
1011         }
1012         of_node_put(np);
1013
1014         return 0;
1015
1016 exit_free:
1017         of_node_put(child);
1018         of_node_put(np);
1019         of_thermal_free_zone(tz);
1020
1021         /* no memory available, so free what we have built */
1022         of_thermal_destroy_zones();
1023
1024         return -ENOMEM;
1025 }
1026
1027 /**
1028  * of_thermal_destroy_zones - remove all zones parsed and allocated resources
1029  *
1030  * Finds all zones parsed and added to the thermal framework and remove them
1031  * from the system, together with their resources.
1032  *
1033  */
1034 void of_thermal_destroy_zones(void)
1035 {
1036         struct device_node *np, *child;
1037
1038         np = of_find_node_by_name(NULL, "thermal-zones");
1039         if (!np) {
1040                 pr_debug("unable to find thermal zones\n");
1041                 return;
1042         }
1043
1044         for_each_available_child_of_node(np, child) {
1045                 struct thermal_zone_device *zone;
1046
1047                 zone = thermal_zone_get_zone_by_name(child->name);
1048                 if (IS_ERR(zone))
1049                         continue;
1050
1051                 thermal_zone_device_unregister(zone);
1052                 kfree(zone->tzp);
1053                 kfree(zone->ops);
1054                 of_thermal_free_zone(zone->devdata);
1055         }
1056         of_node_put(np);
1057 }