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         if (data->ops->set_trip_temp) {
 335                 int ret;
 336
 337                 ret = data->ops->set_trip_temp(data->sensor_data, trip, temp);
 338                 if (ret)
 339                         return ret;
 340         }
 341
 342         /* thermal framework should take care of data->mask & (1 << trip) */
 343         data->trips[trip].temperature = temp;
 344
 345         return 0;
 346 }
 347
 348 static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
 349                                     int *hyst)
 350 {
 351         struct __thermal_zone *data = tz->devdata;
 352
 353         if (trip >= data->ntrips || trip < 0)
 354                 return -EDOM;
 355
 356         *hyst = data->trips[trip].hysteresis;
 357
 358         return 0;
 359 }
 360
 361 static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
 362                                     int hyst)
 363 {
 364         struct __thermal_zone *data = tz->devdata;
 365
 366         if (trip >= data->ntrips || trip < 0)
 367                 return -EDOM;
 368
 369         /* thermal framework should take care of data->mask & (1 << trip) */
 370         data->trips[trip].hysteresis = hyst;
 371
 372         return 0;
 373 }
 374
 375 static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
 376                                     int *temp)
 377 {
 378         struct __thermal_zone *data = tz->devdata;
 379         int i;
 380
 381         for (i = 0; i < data->ntrips; i++)
 382                 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
 383                         *temp = data->trips[i].temperature;
 384                         return 0;
 385                 }
 386
 387         return -EINVAL;
 388 }
 389
 390 static struct thermal_zone_device_ops of_thermal_ops = {
 391         .get_mode = of_thermal_get_mode,
 392         .set_mode = of_thermal_set_mode,
 393
 394         .get_trip_type = of_thermal_get_trip_type,
 395         .get_trip_temp = of_thermal_get_trip_temp,
 396         .set_trip_temp = of_thermal_set_trip_temp,
 397         .get_trip_hyst = of_thermal_get_trip_hyst,
 398         .set_trip_hyst = of_thermal_set_trip_hyst,
 399         .get_crit_temp = of_thermal_get_crit_temp,
 400
 401         .bind = of_thermal_bind,
 402         .unbind = of_thermal_unbind,
 403 };
 404
 405 /***   sensor API   ***/
 406
 407 static struct thermal_zone_device *
 408 thermal_zone_of_add_sensor(struct device_node *zone,
 409                            struct device_node *sensor, void *data,
 410                            const struct thermal_zone_of_device_ops *ops)
 411 {
 412         struct thermal_zone_device *tzd;
 413         struct __thermal_zone *tz;
 414
 415         tzd = thermal_zone_get_zone_by_name(zone->name);
 416         if (IS_ERR(tzd))
 417                 return ERR_PTR(-EPROBE_DEFER);
 418
 419         tz = tzd->devdata;
 420
 421         if (!ops)
 422                 return ERR_PTR(-EINVAL);
 423
 424         mutex_lock(&tzd->lock);
 425         tz->ops = ops;
 426         tz->sensor_data = data;
 427
 428         tzd->ops->get_temp = of_thermal_get_temp;
 429         tzd->ops->get_trend = of_thermal_get_trend;
 430         tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
 431         mutex_unlock(&tzd->lock);
 432
 433         return tzd;
 434 }
 435
 436 /**
 437  * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
 438  * @dev: a valid struct device pointer of a sensor device. Must contain
 439  *       a valid .of_node, for the sensor node.
 440  * @sensor_id: a sensor identifier, in case the sensor IP has more
 441  *             than one sensors
 442  * @data: a private pointer (owned by the caller) that will be passed
 443  *        back, when a temperature reading is needed.
 444  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 445  *
 446  * This function will search the list of thermal zones described in device
 447  * tree and look for the zone that refer to the sensor device pointed by
 448  * @dev->of_node as temperature providers. For the zone pointing to the
 449  * sensor node, the sensor will be added to the DT thermal zone device.
 450  *
 451  * The thermal zone temperature is provided by the @get_temp function
 452  * pointer. When called, it will have the private pointer @data back.
 453  *
 454  * The thermal zone temperature trend is provided by the @get_trend function
 455  * pointer. When called, it will have the private pointer @data back.
 456  *
 457  * TODO:
 458  * 01 - This function must enqueue the new sensor instead of using
 459  * it as the only source of temperature values.
 460  *
 461  * 02 - There must be a way to match the sensor with all thermal zones
 462  * that refer to it.
 463  *
 464  * Return: On success returns a valid struct thermal_zone_device,
 465  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 466  * check the return value with help of IS_ERR() helper.
 467  */
 468 struct thermal_zone_device *
 469 thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
 470                                 const struct thermal_zone_of_device_ops *ops)
 471 {
 472         struct device_node *np, *child, *sensor_np;
 473         struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
 474
 475         np = of_find_node_by_name(NULL, "thermal-zones");
 476         if (!np)
 477                 return ERR_PTR(-ENODEV);
 478
 479         if (!dev || !dev->of_node) {
 480                 of_node_put(np);
 481                 return ERR_PTR(-EINVAL);
 482         }
 483
 484         sensor_np = of_node_get(dev->of_node);
 485
 486         for_each_available_child_of_node(np, child) {
 487                 struct of_phandle_args sensor_specs;
 488                 int ret, id;
 489
 490                 /* For now, thermal framework supports only 1 sensor per zone */
 491                 ret = of_parse_phandle_with_args(child, "thermal-sensors",
 492                                                  "#thermal-sensor-cells",
 493                                                  0, &sensor_specs);
 494                 if (ret)
 495                         continue;
 496
 497                 if (sensor_specs.args_count >= 1) {
 498                         id = sensor_specs.args[0];
 499                         WARN(sensor_specs.args_count > 1,
 500                              "%s: too many cells in sensor specifier %d\n",
 501                              sensor_specs.np->name, sensor_specs.args_count);
 502                 } else {
 503                         id = 0;
 504                 }
 505
 506                 if (sensor_specs.np == sensor_np && id == sensor_id) {
 507                         tzd = thermal_zone_of_add_sensor(child, sensor_np,
 508                                                          data, ops);
 509                         if (!IS_ERR(tzd))
 510                                 tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED);
 511
 512                         of_node_put(sensor_specs.np);
 513                         of_node_put(child);
 514                         goto exit;
 515                 }
 516                 of_node_put(sensor_specs.np);
 517         }
 518 exit:
 519         of_node_put(sensor_np);
 520         of_node_put(np);
 521
 522         return tzd;
 523 }
 524 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
 525
 526 /**
 527  * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
 528  * @dev: a valid struct device pointer of a sensor device. Must contain
 529  *       a valid .of_node, for the sensor node.
 530  * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
 531  *
 532  * This function removes the sensor callbacks and private data from the
 533  * thermal zone device registered with thermal_zone_of_sensor_register()
 534  * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 535  * thermal zone device callbacks.
 536  *
 537  * TODO: When the support to several sensors per zone is added, this
 538  * function must search the sensor list based on @dev parameter.
 539  *
 540  */
 541 void thermal_zone_of_sensor_unregister(struct device *dev,
 542                                        struct thermal_zone_device *tzd)
 543 {
 544         struct __thermal_zone *tz;
 545
 546         if (!dev || !tzd || !tzd->devdata)
 547                 return;
 548
 549         tz = tzd->devdata;
 550
 551         /* no __thermal_zone, nothing to be done */
 552         if (!tz)
 553                 return;
 554
 555         mutex_lock(&tzd->lock);
 556         tzd->ops->get_temp = NULL;
 557         tzd->ops->get_trend = NULL;
 558         tzd->ops->set_emul_temp = NULL;
 559
 560         tz->ops = NULL;
 561         tz->sensor_data = NULL;
 562         mutex_unlock(&tzd->lock);
 563 }
 564 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
 565
 566 static void devm_thermal_zone_of_sensor_release(struct device *dev, void *res)
 567 {
 568         thermal_zone_of_sensor_unregister(dev,
 569                                           *(struct thermal_zone_device **)res);
 570 }
 571
 572 static int devm_thermal_zone_of_sensor_match(struct device *dev, void *res,
 573                                              void *data)
 574 {
 575         struct thermal_zone_device **r = res;
 576
 577         if (WARN_ON(!r || !*r))
 578                 return 0;
 579
 580         return *r == data;
 581 }
 582
 583 /**
 584  * devm_thermal_zone_of_sensor_register - Resource managed version of
 585  *                              thermal_zone_of_sensor_register()
 586  * @dev: a valid struct device pointer of a sensor device. Must contain
 587  *       a valid .of_node, for the sensor node.
 588  * @sensor_id: a sensor identifier, in case the sensor IP has more
 589  *             than one sensors
 590  * @data: a private pointer (owned by the caller) that will be passed
 591  *        back, when a temperature reading is needed.
 592  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 593  *
 594  * Refer thermal_zone_of_sensor_register() for more details.
 595  *
 596  * Return: On success returns a valid struct thermal_zone_device,
 597  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 598  * check the return value with help of IS_ERR() helper.
 599  * Registered hermal_zone_device device will automatically be
 600  * released when device is unbounded.
 601  */
 602 struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
 603         struct device *dev, int sensor_id,
 604         void *data, const struct thermal_zone_of_device_ops *ops)
 605 {
 606         struct thermal_zone_device **ptr, *tzd;
 607
 608         ptr = devres_alloc(devm_thermal_zone_of_sensor_release, sizeof(*ptr),
 609                            GFP_KERNEL);
 610         if (!ptr)
 611                 return ERR_PTR(-ENOMEM);
 612
 613         tzd = thermal_zone_of_sensor_register(dev, sensor_id, data, ops);
 614         if (IS_ERR(tzd)) {
 615                 devres_free(ptr);
 616                 return tzd;
 617         }
 618
 619         *ptr = tzd;
 620         devres_add(dev, ptr);
 621
 622         return tzd;
 623 }
 624 EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_register);
 625
 626 /**
 627  * devm_thermal_zone_of_sensor_unregister - Resource managed version of
 628  *                              thermal_zone_of_sensor_unregister().
 629  * @dev: Device for which which resource was allocated.
 630  * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
 631  *
 632  * This function removes the sensor callbacks and private data from the
 633  * thermal zone device registered with devm_thermal_zone_of_sensor_register()
 634  * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 635  * thermal zone device callbacks.
 636  * Normally this function will not need to be called and the resource
 637  * management code will ensure that the resource is freed.
 638  */
 639 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
 640                                             struct thermal_zone_device *tzd)
 641 {
 642         WARN_ON(devres_release(dev, devm_thermal_zone_of_sensor_release,
 643                                devm_thermal_zone_of_sensor_match, tzd));
 644 }
 645 EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
 646
 647 /***   functions parsing device tree nodes   ***/
 648
 649 /**
 650  * thermal_of_populate_bind_params - parse and fill cooling map data
 651  * @np: DT node containing a cooling-map node
 652  * @__tbp: data structure to be filled with cooling map info
 653  * @trips: array of thermal zone trip points
 654  * @ntrips: number of trip points inside trips.
 655  *
 656  * This function parses a cooling-map type of node represented by
 657  * @np parameter and fills the read data into @__tbp data structure.
 658  * It needs the already parsed array of trip points of the thermal zone
 659  * in consideration.
 660  *
 661  * Return: 0 on success, proper error code otherwise
 662  */
 663 static int thermal_of_populate_bind_params(struct device_node *np,
 664                                            struct __thermal_bind_params *__tbp,
 665                                            struct thermal_trip *trips,
 666                                            int ntrips)
 667 {
 668         struct of_phandle_args cooling_spec;
 669         struct device_node *trip;
 670         int ret, i;
 671         u32 prop;
 672
 673         /* Default weight. Usage is optional */
 674         __tbp->usage = THERMAL_WEIGHT_DEFAULT;
 675         ret = of_property_read_u32(np, "contribution", &prop);
 676         if (ret == 0)
 677                 __tbp->usage = prop;
 678
 679         trip = of_parse_phandle(np, "trip", 0);
 680         if (!trip) {
 681                 pr_err("missing trip property\n");
 682                 return -ENODEV;
 683         }
 684
 685         /* match using device_node */
 686         for (i = 0; i < ntrips; i++)
 687                 if (trip == trips[i].np) {
 688                         __tbp->trip_id = i;
 689                         break;
 690                 }
 691
 692         if (i == ntrips) {
 693                 ret = -ENODEV;
 694                 goto end;
 695         }
 696
 697         ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
 698                                          0, &cooling_spec);
 699         if (ret < 0) {
 700                 pr_err("missing cooling_device property\n");
 701                 goto end;
 702         }
 703         __tbp->cooling_device = cooling_spec.np;
 704         if (cooling_spec.args_count >= 2) { /* at least min and max */
 705                 __tbp->min = cooling_spec.args[0];
 706                 __tbp->max = cooling_spec.args[1];
 707         } else {
 708                 pr_err("wrong reference to cooling device, missing limits\n");
 709         }
 710
 711 end:
 712         of_node_put(trip);
 713
 714         return ret;
 715 }
 716
 717 /**
 718  * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
 719  * into the device tree binding of 'trip', property type.
 720  */
 721 static const char * const trip_types[] = {
 722         [THERMAL_TRIP_ACTIVE]   = "active",
 723         [THERMAL_TRIP_PASSIVE]  = "passive",
 724         [THERMAL_TRIP_HOT]      = "hot",
 725         [THERMAL_TRIP_CRITICAL] = "critical",
 726 };
 727
 728 /**
 729  * thermal_of_get_trip_type - Get phy mode for given device_node
 730  * @np: Pointer to the given device_node
 731  * @type: Pointer to resulting trip type
 732  *
 733  * The function gets trip type string from property 'type',
 734  * and store its index in trip_types table in @type,
 735  *
 736  * Return: 0 on success, or errno in error case.
 737  */
 738 static int thermal_of_get_trip_type(struct device_node *np,
 739                                     enum thermal_trip_type *type)
 740 {
 741         const char *t;
 742         int err, i;
 743
 744         err = of_property_read_string(np, "type", &t);
 745         if (err < 0)
 746                 return err;
 747
 748         for (i = 0; i < ARRAY_SIZE(trip_types); i++)
 749                 if (!strcasecmp(t, trip_types[i])) {
 750                         *type = i;
 751                         return 0;
 752                 }
 753
 754         return -ENODEV;
 755 }
 756
 757 /**
 758  * thermal_of_populate_trip - parse and fill one trip point data
 759  * @np: DT node containing a trip point node
 760  * @trip: trip point data structure to be filled up
 761  *
 762  * This function parses a trip point type of node represented by
 763  * @np parameter and fills the read data into @trip data structure.
 764  *
 765  * Return: 0 on success, proper error code otherwise
 766  */
 767 static int thermal_of_populate_trip(struct device_node *np,
 768                                     struct thermal_trip *trip)
 769 {
 770         int prop;
 771         int ret;
 772
 773         ret = of_property_read_u32(np, "temperature", &prop);
 774         if (ret < 0) {
 775                 pr_err("missing temperature property\n");
 776                 return ret;
 777         }
 778         trip->temperature = prop;
 779
 780         ret = of_property_read_u32(np, "hysteresis", &prop);
 781         if (ret < 0) {
 782                 pr_err("missing hysteresis property\n");
 783                 return ret;
 784         }
 785         trip->hysteresis = prop;
 786
 787         ret = thermal_of_get_trip_type(np, &trip->type);
 788         if (ret < 0) {
 789                 pr_err("wrong trip type property\n");
 790                 return ret;
 791         }
 792
 793         /* Required for cooling map matching */
 794         trip->np = np;
 795         of_node_get(np);
 796
 797         return 0;
 798 }
 799
 800 /**
 801  * thermal_of_build_thermal_zone - parse and fill one thermal zone data
 802  * @np: DT node containing a thermal zone node
 803  *
 804  * This function parses a thermal zone type of node represented by
 805  * @np parameter and fills the read data into a __thermal_zone data structure
 806  * and return this pointer.
 807  *
 808  * TODO: Missing properties to parse: thermal-sensor-names
 809  *
 810  * Return: On success returns a valid struct __thermal_zone,
 811  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 812  * check the return value with help of IS_ERR() helper.
 813  */
 814 static struct __thermal_zone
 815 __init *thermal_of_build_thermal_zone(struct device_node *np)
 816 {
 817         struct device_node *child = NULL, *gchild;
 818         struct __thermal_zone *tz;
 819         int ret, i;
 820         u32 prop, coef[2];
 821
 822         if (!np) {
 823                 pr_err("no thermal zone np\n");
 824                 return ERR_PTR(-EINVAL);
 825         }
 826
 827         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
 828         if (!tz)
 829                 return ERR_PTR(-ENOMEM);
 830
 831         ret = of_property_read_u32(np, "polling-delay-passive", &prop);
 832         if (ret < 0) {
 833                 pr_err("missing polling-delay-passive property\n");
 834                 goto free_tz;
 835         }
 836         tz->passive_delay = prop;
 837
 838         ret = of_property_read_u32(np, "polling-delay", &prop);
 839         if (ret < 0) {
 840                 pr_err("missing polling-delay property\n");
 841                 goto free_tz;
 842         }
 843         tz->polling_delay = prop;
 844
 845         /*
 846          * REVIST: for now, the thermal framework supports only
 847          * one sensor per thermal zone. Thus, we are considering
 848          * only the first two values as slope and offset.
 849          */
 850         ret = of_property_read_u32_array(np, "coefficients", coef, 2);
 851         if (ret == 0) {
 852                 tz->slope = coef[0];
 853                 tz->offset = coef[1];
 854         } else {
 855                 tz->slope = 1;
 856                 tz->offset = 0;
 857         }
 858
 859         /* trips */
 860         child = of_get_child_by_name(np, "trips");
 861
 862         /* No trips provided */
 863         if (!child)
 864                 goto finish;
 865
 866         tz->ntrips = of_get_child_count(child);
 867         if (tz->ntrips == 0) /* must have at least one child */
 868                 goto finish;
 869
 870         tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
 871         if (!tz->trips) {
 872                 ret = -ENOMEM;
 873                 goto free_tz;
 874         }
 875
 876         i = 0;
 877         for_each_child_of_node(child, gchild) {
 878                 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
 879                 if (ret)
 880                         goto free_trips;
 881         }
 882
 883         of_node_put(child);
 884
 885         /* cooling-maps */
 886         child = of_get_child_by_name(np, "cooling-maps");
 887
 888         /* cooling-maps not provided */
 889         if (!child)
 890                 goto finish;
 891
 892         tz->num_tbps = of_get_child_count(child);
 893         if (tz->num_tbps == 0)
 894                 goto finish;
 895
 896         tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
 897         if (!tz->tbps) {
 898                 ret = -ENOMEM;
 899                 goto free_trips;
 900         }
 901
 902         i = 0;
 903         for_each_child_of_node(child, gchild) {
 904                 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
 905                                                       tz->trips, tz->ntrips);
 906                 if (ret)
 907                         goto free_tbps;
 908         }
 909
 910 finish:
 911         of_node_put(child);
 912         tz->mode = THERMAL_DEVICE_DISABLED;
 913
 914         return tz;
 915
 916 free_tbps:
 917         for (i = i - 1; i >= 0; i--)
 918                 of_node_put(tz->tbps[i].cooling_device);
 919         kfree(tz->tbps);
 920 free_trips:
 921         for (i = 0; i < tz->ntrips; i++)
 922                 of_node_put(tz->trips[i].np);
 923         kfree(tz->trips);
 924         of_node_put(gchild);
 925 free_tz:
 926         kfree(tz);
 927         of_node_put(child);
 928
 929         return ERR_PTR(ret);
 930 }
 931
 932 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
 933 {
 934         int i;
 935
 936         for (i = 0; i < tz->num_tbps; i++)
 937                 of_node_put(tz->tbps[i].cooling_device);
 938         kfree(tz->tbps);
 939         for (i = 0; i < tz->ntrips; i++)
 940                 of_node_put(tz->trips[i].np);
 941         kfree(tz->trips);
 942         kfree(tz);
 943 }
 944
 945 /**
 946  * of_parse_thermal_zones - parse device tree thermal data
 947  *
 948  * Initialization function that can be called by machine initialization
 949  * code to parse thermal data and populate the thermal framework
 950  * with hardware thermal zones info. This function only parses thermal zones.
 951  * Cooling devices and sensor devices nodes are supposed to be parsed
 952  * by their respective drivers.
 953  *
 954  * Return: 0 on success, proper error code otherwise
 955  *
 956  */
 957 int __init of_parse_thermal_zones(void)
 958 {
 959         struct device_node *np, *child;
 960         struct __thermal_zone *tz;
 961         struct thermal_zone_device_ops *ops;
 962
 963         np = of_find_node_by_name(NULL, "thermal-zones");
 964         if (!np) {
 965                 pr_debug("unable to find thermal zones\n");
 966                 return 0; /* Run successfully on systems without thermal DT */
 967         }
 968
 969         for_each_available_child_of_node(np, child) {
 970                 struct thermal_zone_device *zone;
 971                 struct thermal_zone_params *tzp;
 972                 int i, mask = 0;
 973                 u32 prop;
 974
 975                 tz = thermal_of_build_thermal_zone(child);
 976                 if (IS_ERR(tz)) {
 977                         pr_err("failed to build thermal zone %s: %ld\n",
 978                                child->name,
 979                                PTR_ERR(tz));
 980                         continue;
 981                 }
 982
 983                 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
 984                 if (!ops)
 985                         goto exit_free;
 986
 987                 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
 988                 if (!tzp) {
 989                         kfree(ops);
 990                         goto exit_free;
 991                 }
 992
 993                 /* No hwmon because there might be hwmon drivers registering */
 994                 tzp->no_hwmon = true;
 995
 996                 if (!of_property_read_u32(child, "sustainable-power", &prop))
 997                         tzp->sustainable_power = prop;
 998
 999                 for (i = 0; i < tz->ntrips; i++)
1000                         mask |= 1 << i;
1001
1002                 /* these two are left for temperature drivers to use */
1003                 tzp->slope = tz->slope;
1004                 tzp->offset = tz->offset;
1005
1006                 zone = thermal_zone_device_register(child->name, tz->ntrips,
1007                                                     mask, tz,
1008                                                     ops, tzp,
1009                                                     tz->passive_delay,
1010                                                     tz->polling_delay);
1011                 if (IS_ERR(zone)) {
1012                         pr_err("Failed to build %s zone %ld\n", child->name,
1013                                PTR_ERR(zone));
1014                         kfree(tzp);
1015                         kfree(ops);
1016                         of_thermal_free_zone(tz);
1017                         /* attempting to build remaining zones still */
1018                 }
1019         }
1020         of_node_put(np);
1021
1022         return 0;
1023
1024 exit_free:
1025         of_node_put(child);
1026         of_node_put(np);
1027         of_thermal_free_zone(tz);
1028
1029         /* no memory available, so free what we have built */
1030         of_thermal_destroy_zones();
1031
1032         return -ENOMEM;
1033 }
1034
1035 /**
1036  * of_thermal_destroy_zones - remove all zones parsed and allocated resources
1037  *
1038  * Finds all zones parsed and added to the thermal framework and remove them
1039  * from the system, together with their resources.
1040  *
1041  */
1042 void of_thermal_destroy_zones(void)
1043 {
1044         struct device_node *np, *child;
1045
1046         np = of_find_node_by_name(NULL, "thermal-zones");
1047         if (!np) {
1048                 pr_debug("unable to find thermal zones\n");
1049                 return;
1050         }
1051
1052         for_each_available_child_of_node(np, child) {
1053                 struct thermal_zone_device *zone;
1054
1055                 zone = thermal_zone_get_zone_by_name(child->name);
1056                 if (IS_ERR(zone))
1057                         continue;
1058
1059                 thermal_zone_device_unregister(zone);
1060                 kfree(zone->tzp);
1061                 kfree(zone->ops);
1062                 of_thermal_free_zone(zone->devdata);
1063         }
1064         of_node_put(np);
1065 }