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 static int of_thermal_set_trips(struct thermal_zone_device *tz,
 105                                 int low, int high)
 106 {
 107         struct __thermal_zone *data = tz->devdata;
 108
 109         if (!data->ops || !data->ops->set_trips)
 110                 return -EINVAL;
 111
 112         return data->ops->set_trips(data->sensor_data, low, high);
 113 }
 114
 115 /**
 116  * of_thermal_get_ntrips - function to export number of available trip
 117  *                         points.
 118  * @tz: pointer to a thermal zone
 119  *
 120  * This function is a globally visible wrapper to get number of trip points
 121  * stored in the local struct __thermal_zone
 122  *
 123  * Return: number of available trip points, -ENODEV when data not available
 124  */
 125 int of_thermal_get_ntrips(struct thermal_zone_device *tz)
 126 {
 127         struct __thermal_zone *data = tz->devdata;
 128
 129         if (!data || IS_ERR(data))
 130                 return -ENODEV;
 131
 132         return data->ntrips;
 133 }
 134 EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);
 135
 136 /**
 137  * of_thermal_is_trip_valid - function to check if trip point is valid
 138  *
 139  * @tz: pointer to a thermal zone
 140  * @trip:       trip point to evaluate
 141  *
 142  * This function is responsible for checking if passed trip point is valid
 143  *
 144  * Return: true if trip point is valid, false otherwise
 145  */
 146 bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
 147 {
 148         struct __thermal_zone *data = tz->devdata;
 149
 150         if (!data || trip >= data->ntrips || trip < 0)
 151                 return false;
 152
 153         return true;
 154 }
 155 EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);
 156
 157 /**
 158  * of_thermal_get_trip_points - function to get access to a globally exported
 159  *                              trip points
 160  *
 161  * @tz: pointer to a thermal zone
 162  *
 163  * This function provides a pointer to trip points table
 164  *
 165  * Return: pointer to trip points table, NULL otherwise
 166  */
 167 const struct thermal_trip *
 168 of_thermal_get_trip_points(struct thermal_zone_device *tz)
 169 {
 170         struct __thermal_zone *data = tz->devdata;
 171
 172         if (!data)
 173                 return NULL;
 174
 175         return data->trips;
 176 }
 177 EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);
 178
 179 /**
 180  * of_thermal_set_emul_temp - function to set emulated temperature
 181  *
 182  * @tz: pointer to a thermal zone
 183  * @temp:       temperature to set
 184  *
 185  * This function gives the ability to set emulated value of temperature,
 186  * which is handy for debugging
 187  *
 188  * Return: zero on success, error code otherwise
 189  */
 190 static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
 191                                     int temp)
 192 {
 193         struct __thermal_zone *data = tz->devdata;
 194
 195         return data->ops->set_emul_temp(data->sensor_data, temp);
 196 }
 197
 198 static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
 199                                 enum thermal_trend *trend)
 200 {
 201         struct __thermal_zone *data = tz->devdata;
 202
 203         if (!data->ops->get_trend)
 204                 return -EINVAL;
 205
 206         return data->ops->get_trend(data->sensor_data, trip, trend);
 207 }
 208
 209 static int of_thermal_bind(struct thermal_zone_device *thermal,
 210                            struct thermal_cooling_device *cdev)
 211 {
 212         struct __thermal_zone *data = thermal->devdata;
 213         int i;
 214
 215         if (!data || IS_ERR(data))
 216                 return -ENODEV;
 217
 218         /* find where to bind */
 219         for (i = 0; i < data->num_tbps; i++) {
 220                 struct __thermal_bind_params *tbp = data->tbps + i;
 221
 222                 if (tbp->cooling_device == cdev->np) {
 223                         int ret;
 224
 225                         ret = thermal_zone_bind_cooling_device(thermal,
 226                                                 tbp->trip_id, cdev,
 227                                                 tbp->max,
 228                                                 tbp->min,
 229                                                 tbp->usage);
 230                         if (ret)
 231                                 return ret;
 232                 }
 233         }
 234
 235         return 0;
 236 }
 237
 238 static int of_thermal_unbind(struct thermal_zone_device *thermal,
 239                              struct thermal_cooling_device *cdev)
 240 {
 241         struct __thermal_zone *data = thermal->devdata;
 242         int i;
 243
 244         if (!data || IS_ERR(data))
 245                 return -ENODEV;
 246
 247         /* find where to unbind */
 248         for (i = 0; i < data->num_tbps; i++) {
 249                 struct __thermal_bind_params *tbp = data->tbps + i;
 250
 251                 if (tbp->cooling_device == cdev->np) {
 252                         int ret;
 253
 254                         ret = thermal_zone_unbind_cooling_device(thermal,
 255                                                 tbp->trip_id, cdev);
 256                         if (ret)
 257                                 return ret;
 258                 }
 259         }
 260
 261         return 0;
 262 }
 263
 264 static int of_thermal_get_mode(struct thermal_zone_device *tz,
 265                                enum thermal_device_mode *mode)
 266 {
 267         struct __thermal_zone *data = tz->devdata;
 268
 269         *mode = data->mode;
 270
 271         return 0;
 272 }
 273
 274 static int of_thermal_set_mode(struct thermal_zone_device *tz,
 275                                enum thermal_device_mode mode)
 276 {
 277         struct __thermal_zone *data = tz->devdata;
 278
 279         mutex_lock(&tz->lock);
 280
 281         if (mode == THERMAL_DEVICE_ENABLED)
 282                 tz->polling_delay = data->polling_delay;
 283         else
 284                 tz->polling_delay = 0;
 285
 286         mutex_unlock(&tz->lock);
 287
 288         data->mode = mode;
 289         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 290
 291         return 0;
 292 }
 293
 294 static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
 295                                     enum thermal_trip_type *type)
 296 {
 297         struct __thermal_zone *data = tz->devdata;
 298
 299         if (trip >= data->ntrips || trip < 0)
 300                 return -EDOM;
 301
 302         *type = data->trips[trip].type;
 303
 304         return 0;
 305 }
 306
 307 static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
 308                                     int *temp)
 309 {
 310         struct __thermal_zone *data = tz->devdata;
 311
 312         if (trip >= data->ntrips || trip < 0)
 313                 return -EDOM;
 314
 315         *temp = data->trips[trip].temperature;
 316
 317         return 0;
 318 }
 319
 320 static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
 321                                     int temp)
 322 {
 323         struct __thermal_zone *data = tz->devdata;
 324
 325         if (trip >= data->ntrips || trip < 0)
 326                 return -EDOM;
 327
 328         if (data->ops->set_trip_temp) {
 329                 int ret;
 330
 331                 ret = data->ops->set_trip_temp(data->sensor_data, trip, temp);
 332                 if (ret)
 333                         return ret;
 334         }
 335
 336         /* thermal framework should take care of data->mask & (1 << trip) */
 337         data->trips[trip].temperature = temp;
 338
 339         return 0;
 340 }
 341
 342 static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
 343                                     int *hyst)
 344 {
 345         struct __thermal_zone *data = tz->devdata;
 346
 347         if (trip >= data->ntrips || trip < 0)
 348                 return -EDOM;
 349
 350         *hyst = data->trips[trip].hysteresis;
 351
 352         return 0;
 353 }
 354
 355 static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
 356                                     int hyst)
 357 {
 358         struct __thermal_zone *data = tz->devdata;
 359
 360         if (trip >= data->ntrips || trip < 0)
 361                 return -EDOM;
 362
 363         /* thermal framework should take care of data->mask & (1 << trip) */
 364         data->trips[trip].hysteresis = hyst;
 365
 366         return 0;
 367 }
 368
 369 static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
 370                                     int *temp)
 371 {
 372         struct __thermal_zone *data = tz->devdata;
 373         int i;
 374
 375         for (i = 0; i < data->ntrips; i++)
 376                 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
 377                         *temp = data->trips[i].temperature;
 378                         return 0;
 379                 }
 380
 381         return -EINVAL;
 382 }
 383
 384 static struct thermal_zone_device_ops of_thermal_ops = {
 385         .get_mode = of_thermal_get_mode,
 386         .set_mode = of_thermal_set_mode,
 387
 388         .get_trip_type = of_thermal_get_trip_type,
 389         .get_trip_temp = of_thermal_get_trip_temp,
 390         .set_trip_temp = of_thermal_set_trip_temp,
 391         .get_trip_hyst = of_thermal_get_trip_hyst,
 392         .set_trip_hyst = of_thermal_set_trip_hyst,
 393         .get_crit_temp = of_thermal_get_crit_temp,
 394
 395         .bind = of_thermal_bind,
 396         .unbind = of_thermal_unbind,
 397 };
 398
 399 /***   sensor API   ***/
 400
 401 static struct thermal_zone_device *
 402 thermal_zone_of_add_sensor(struct device_node *zone,
 403                            struct device_node *sensor, void *data,
 404                            const struct thermal_zone_of_device_ops *ops)
 405 {
 406         struct thermal_zone_device *tzd;
 407         struct __thermal_zone *tz;
 408
 409         tzd = thermal_zone_get_zone_by_name(zone->name);
 410         if (IS_ERR(tzd))
 411                 return ERR_PTR(-EPROBE_DEFER);
 412
 413         tz = tzd->devdata;
 414
 415         if (!ops)
 416                 return ERR_PTR(-EINVAL);
 417
 418         mutex_lock(&tzd->lock);
 419         tz->ops = ops;
 420         tz->sensor_data = data;
 421
 422         tzd->ops->get_temp = of_thermal_get_temp;
 423         tzd->ops->get_trend = of_thermal_get_trend;
 424
 425         /*
 426          * The thermal zone core will calculate the window if they have set the
 427          * optional set_trips pointer.
 428          */
 429         if (ops->set_trips)
 430                 tzd->ops->set_trips = of_thermal_set_trips;
 431
 432         if (ops->set_emul_temp)
 433                 tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
 434
 435         mutex_unlock(&tzd->lock);
 436
 437         return tzd;
 438 }
 439
 440 /**
 441  * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
 442  * @dev: a valid struct device pointer of a sensor device. Must contain
 443  *       a valid .of_node, for the sensor node.
 444  * @sensor_id: a sensor identifier, in case the sensor IP has more
 445  *             than one sensors
 446  * @data: a private pointer (owned by the caller) that will be passed
 447  *        back, when a temperature reading is needed.
 448  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 449  *
 450  * This function will search the list of thermal zones described in device
 451  * tree and look for the zone that refer to the sensor device pointed by
 452  * @dev->of_node as temperature providers. For the zone pointing to the
 453  * sensor node, the sensor will be added to the DT thermal zone device.
 454  *
 455  * The thermal zone temperature is provided by the @get_temp function
 456  * pointer. When called, it will have the private pointer @data back.
 457  *
 458  * The thermal zone temperature trend is provided by the @get_trend function
 459  * pointer. When called, it will have the private pointer @data back.
 460  *
 461  * TODO:
 462  * 01 - This function must enqueue the new sensor instead of using
 463  * it as the only source of temperature values.
 464  *
 465  * 02 - There must be a way to match the sensor with all thermal zones
 466  * that refer to it.
 467  *
 468  * Return: On success returns a valid struct thermal_zone_device,
 469  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 470  * check the return value with help of IS_ERR() helper.
 471  */
 472 struct thermal_zone_device *
 473 thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
 474                                 const struct thermal_zone_of_device_ops *ops)
 475 {
 476         struct device_node *np, *child, *sensor_np;
 477         struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
 478
 479         np = of_find_node_by_name(NULL, "thermal-zones");
 480         if (!np)
 481                 return ERR_PTR(-ENODEV);
 482
 483         if (!dev || !dev->of_node) {
 484                 of_node_put(np);
 485                 return ERR_PTR(-EINVAL);
 486         }
 487
 488         sensor_np = of_node_get(dev->of_node);
 489
 490         for_each_available_child_of_node(np, child) {
 491                 struct of_phandle_args sensor_specs;
 492                 int ret, id;
 493
 494                 /* For now, thermal framework supports only 1 sensor per zone */
 495                 ret = of_parse_phandle_with_args(child, "thermal-sensors",
 496                                                  "#thermal-sensor-cells",
 497                                                  0, &sensor_specs);
 498                 if (ret)
 499                         continue;
 500
 501                 if (sensor_specs.args_count >= 1) {
 502                         id = sensor_specs.args[0];
 503                         WARN(sensor_specs.args_count > 1,
 504                              "%s: too many cells in sensor specifier %d\n",
 505                              sensor_specs.np->name, sensor_specs.args_count);
 506                 } else {
 507                         id = 0;
 508                 }
 509
 510                 if (sensor_specs.np == sensor_np && id == sensor_id) {
 511                         tzd = thermal_zone_of_add_sensor(child, sensor_np,
 512                                                          data, ops);
 513                         if (!IS_ERR(tzd))
 514                                 tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED);
 515
 516                         of_node_put(sensor_specs.np);
 517                         of_node_put(child);
 518                         goto exit;
 519                 }
 520                 of_node_put(sensor_specs.np);
 521         }
 522 exit:
 523         of_node_put(sensor_np);
 524         of_node_put(np);
 525
 526         return tzd;
 527 }
 528 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
 529
 530 /**
 531  * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
 532  * @dev: a valid struct device pointer of a sensor device. Must contain
 533  *       a valid .of_node, for the sensor node.
 534  * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
 535  *
 536  * This function removes the sensor callbacks and private data from the
 537  * thermal zone device registered with thermal_zone_of_sensor_register()
 538  * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 539  * thermal zone device callbacks.
 540  *
 541  * TODO: When the support to several sensors per zone is added, this
 542  * function must search the sensor list based on @dev parameter.
 543  *
 544  */
 545 void thermal_zone_of_sensor_unregister(struct device *dev,
 546                                        struct thermal_zone_device *tzd)
 547 {
 548         struct __thermal_zone *tz;
 549
 550         if (!dev || !tzd || !tzd->devdata)
 551                 return;
 552
 553         tz = tzd->devdata;
 554
 555         /* no __thermal_zone, nothing to be done */
 556         if (!tz)
 557                 return;
 558
 559         mutex_lock(&tzd->lock);
 560         tzd->ops->get_temp = NULL;
 561         tzd->ops->get_trend = NULL;
 562         tzd->ops->set_emul_temp = NULL;
 563
 564         tz->ops = NULL;
 565         tz->sensor_data = NULL;
 566         mutex_unlock(&tzd->lock);
 567 }
 568 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
 569
 570 static void devm_thermal_zone_of_sensor_release(struct device *dev, void *res)
 571 {
 572         thermal_zone_of_sensor_unregister(dev,
 573                                           *(struct thermal_zone_device **)res);
 574 }
 575
 576 static int devm_thermal_zone_of_sensor_match(struct device *dev, void *res,
 577                                              void *data)
 578 {
 579         struct thermal_zone_device **r = res;
 580
 581         if (WARN_ON(!r || !*r))
 582                 return 0;
 583
 584         return *r == data;
 585 }
 586
 587 /**
 588  * devm_thermal_zone_of_sensor_register - Resource managed version of
 589  *                              thermal_zone_of_sensor_register()
 590  * @dev: a valid struct device pointer of a sensor device. Must contain
 591  *       a valid .of_node, for the sensor node.
 592  * @sensor_id: a sensor identifier, in case the sensor IP has more
 593  *             than one sensors
 594  * @data: a private pointer (owned by the caller) that will be passed
 595  *        back, when a temperature reading is needed.
 596  * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
 597  *
 598  * Refer thermal_zone_of_sensor_register() for more details.
 599  *
 600  * Return: On success returns a valid struct thermal_zone_device,
 601  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 602  * check the return value with help of IS_ERR() helper.
 603  * Registered thermal_zone_device device will automatically be
 604  * released when device is unbounded.
 605  */
 606 struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
 607         struct device *dev, int sensor_id,
 608         void *data, const struct thermal_zone_of_device_ops *ops)
 609 {
 610         struct thermal_zone_device **ptr, *tzd;
 611
 612         ptr = devres_alloc(devm_thermal_zone_of_sensor_release, sizeof(*ptr),
 613                            GFP_KERNEL);
 614         if (!ptr)
 615                 return ERR_PTR(-ENOMEM);
 616
 617         tzd = thermal_zone_of_sensor_register(dev, sensor_id, data, ops);
 618         if (IS_ERR(tzd)) {
 619                 devres_free(ptr);
 620                 return tzd;
 621         }
 622
 623         *ptr = tzd;
 624         devres_add(dev, ptr);
 625
 626         return tzd;
 627 }
 628 EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_register);
 629
 630 /**
 631  * devm_thermal_zone_of_sensor_unregister - Resource managed version of
 632  *                              thermal_zone_of_sensor_unregister().
 633  * @dev: Device for which which resource was allocated.
 634  * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
 635  *
 636  * This function removes the sensor callbacks and private data from the
 637  * thermal zone device registered with devm_thermal_zone_of_sensor_register()
 638  * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 639  * thermal zone device callbacks.
 640  * Normally this function will not need to be called and the resource
 641  * management code will ensure that the resource is freed.
 642  */
 643 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
 644                                             struct thermal_zone_device *tzd)
 645 {
 646         WARN_ON(devres_release(dev, devm_thermal_zone_of_sensor_release,
 647                                devm_thermal_zone_of_sensor_match, tzd));
 648 }
 649 EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
 650
 651 /***   functions parsing device tree nodes   ***/
 652
 653 /**
 654  * thermal_of_populate_bind_params - parse and fill cooling map data
 655  * @np: DT node containing a cooling-map node
 656  * @__tbp: data structure to be filled with cooling map info
 657  * @trips: array of thermal zone trip points
 658  * @ntrips: number of trip points inside trips.
 659  *
 660  * This function parses a cooling-map type of node represented by
 661  * @np parameter and fills the read data into @__tbp data structure.
 662  * It needs the already parsed array of trip points of the thermal zone
 663  * in consideration.
 664  *
 665  * Return: 0 on success, proper error code otherwise
 666  */
 667 static int thermal_of_populate_bind_params(struct device_node *np,
 668                                            struct __thermal_bind_params *__tbp,
 669                                            struct thermal_trip *trips,
 670                                            int ntrips)
 671 {
 672         struct of_phandle_args cooling_spec;
 673         struct device_node *trip;
 674         int ret, i;
 675         u32 prop;
 676
 677         /* Default weight. Usage is optional */
 678         __tbp->usage = THERMAL_WEIGHT_DEFAULT;
 679         ret = of_property_read_u32(np, "contribution", &prop);
 680         if (ret == 0)
 681                 __tbp->usage = prop;
 682
 683         trip = of_parse_phandle(np, "trip", 0);
 684         if (!trip) {
 685                 pr_err("missing trip property\n");
 686                 return -ENODEV;
 687         }
 688
 689         /* match using device_node */
 690         for (i = 0; i < ntrips; i++)
 691                 if (trip == trips[i].np) {
 692                         __tbp->trip_id = i;
 693                         break;
 694                 }
 695
 696         if (i == ntrips) {
 697                 ret = -ENODEV;
 698                 goto end;
 699         }
 700
 701         ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
 702                                          0, &cooling_spec);
 703         if (ret < 0) {
 704                 pr_err("missing cooling_device property\n");
 705                 goto end;
 706         }
 707         __tbp->cooling_device = cooling_spec.np;
 708         if (cooling_spec.args_count >= 2) { /* at least min and max */
 709                 __tbp->min = cooling_spec.args[0];
 710                 __tbp->max = cooling_spec.args[1];
 711         } else {
 712                 pr_err("wrong reference to cooling device, missing limits\n");
 713         }
 714
 715 end:
 716         of_node_put(trip);
 717
 718         return ret;
 719 }
 720
 721 /**
 722  * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
 723  * into the device tree binding of 'trip', property type.
 724  */
 725 static const char * const trip_types[] = {
 726         [THERMAL_TRIP_ACTIVE]   = "active",
 727         [THERMAL_TRIP_PASSIVE]  = "passive",
 728         [THERMAL_TRIP_HOT]      = "hot",
 729         [THERMAL_TRIP_CRITICAL] = "critical",
 730 };
 731
 732 /**
 733  * thermal_of_get_trip_type - Get phy mode for given device_node
 734  * @np: Pointer to the given device_node
 735  * @type: Pointer to resulting trip type
 736  *
 737  * The function gets trip type string from property 'type',
 738  * and store its index in trip_types table in @type,
 739  *
 740  * Return: 0 on success, or errno in error case.
 741  */
 742 static int thermal_of_get_trip_type(struct device_node *np,
 743                                     enum thermal_trip_type *type)
 744 {
 745         const char *t;
 746         int err, i;
 747
 748         err = of_property_read_string(np, "type", &t);
 749         if (err < 0)
 750                 return err;
 751
 752         for (i = 0; i < ARRAY_SIZE(trip_types); i++)
 753                 if (!strcasecmp(t, trip_types[i])) {
 754                         *type = i;
 755                         return 0;
 756                 }
 757
 758         return -ENODEV;
 759 }
 760
 761 /**
 762  * thermal_of_populate_trip - parse and fill one trip point data
 763  * @np: DT node containing a trip point node
 764  * @trip: trip point data structure to be filled up
 765  *
 766  * This function parses a trip point type of node represented by
 767  * @np parameter and fills the read data into @trip data structure.
 768  *
 769  * Return: 0 on success, proper error code otherwise
 770  */
 771 static int thermal_of_populate_trip(struct device_node *np,
 772                                     struct thermal_trip *trip)
 773 {
 774         int prop;
 775         int ret;
 776
 777         ret = of_property_read_u32(np, "temperature", &prop);
 778         if (ret < 0) {
 779                 pr_err("missing temperature property\n");
 780                 return ret;
 781         }
 782         trip->temperature = prop;
 783
 784         ret = of_property_read_u32(np, "hysteresis", &prop);
 785         if (ret < 0) {
 786                 pr_err("missing hysteresis property\n");
 787                 return ret;
 788         }
 789         trip->hysteresis = prop;
 790
 791         ret = thermal_of_get_trip_type(np, &trip->type);
 792         if (ret < 0) {
 793                 pr_err("wrong trip type property\n");
 794                 return ret;
 795         }
 796
 797         /* Required for cooling map matching */
 798         trip->np = np;
 799         of_node_get(np);
 800
 801         return 0;
 802 }
 803
 804 /**
 805  * thermal_of_build_thermal_zone - parse and fill one thermal zone data
 806  * @np: DT node containing a thermal zone node
 807  *
 808  * This function parses a thermal zone type of node represented by
 809  * @np parameter and fills the read data into a __thermal_zone data structure
 810  * and return this pointer.
 811  *
 812  * TODO: Missing properties to parse: thermal-sensor-names
 813  *
 814  * Return: On success returns a valid struct __thermal_zone,
 815  * otherwise, it returns a corresponding ERR_PTR(). Caller must
 816  * check the return value with help of IS_ERR() helper.
 817  */
 818 static struct __thermal_zone
 819 __init *thermal_of_build_thermal_zone(struct device_node *np)
 820 {
 821         struct device_node *child = NULL, *gchild;
 822         struct __thermal_zone *tz;
 823         int ret, i;
 824         u32 prop, coef[2];
 825
 826         if (!np) {
 827                 pr_err("no thermal zone np\n");
 828                 return ERR_PTR(-EINVAL);
 829         }
 830
 831         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
 832         if (!tz)
 833                 return ERR_PTR(-ENOMEM);
 834
 835         ret = of_property_read_u32(np, "polling-delay-passive", &prop);
 836         if (ret < 0) {
 837                 pr_err("missing polling-delay-passive property\n");
 838                 goto free_tz;
 839         }
 840         tz->passive_delay = prop;
 841
 842         ret = of_property_read_u32(np, "polling-delay", &prop);
 843         if (ret < 0) {
 844                 pr_err("missing polling-delay property\n");
 845                 goto free_tz;
 846         }
 847         tz->polling_delay = prop;
 848
 849         /*
 850          * REVIST: for now, the thermal framework supports only
 851          * one sensor per thermal zone. Thus, we are considering
 852          * only the first two values as slope and offset.
 853          */
 854         ret = of_property_read_u32_array(np, "coefficients", coef, 2);
 855         if (ret == 0) {
 856                 tz->slope = coef[0];
 857                 tz->offset = coef[1];
 858         } else {
 859                 tz->slope = 1;
 860                 tz->offset = 0;
 861         }
 862
 863         /* trips */
 864         child = of_get_child_by_name(np, "trips");
 865
 866         /* No trips provided */
 867         if (!child)
 868                 goto finish;
 869
 870         tz->ntrips = of_get_child_count(child);
 871         if (tz->ntrips == 0) /* must have at least one child */
 872                 goto finish;
 873
 874         tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
 875         if (!tz->trips) {
 876                 ret = -ENOMEM;
 877                 goto free_tz;
 878         }
 879
 880         i = 0;
 881         for_each_child_of_node(child, gchild) {
 882                 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
 883                 if (ret)
 884                         goto free_trips;
 885         }
 886
 887         of_node_put(child);
 888
 889         /* cooling-maps */
 890         child = of_get_child_by_name(np, "cooling-maps");
 891
 892         /* cooling-maps not provided */
 893         if (!child)
 894                 goto finish;
 895
 896         tz->num_tbps = of_get_child_count(child);
 897         if (tz->num_tbps == 0)
 898                 goto finish;
 899
 900         tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
 901         if (!tz->tbps) {
 902                 ret = -ENOMEM;
 903                 goto free_trips;
 904         }
 905
 906         i = 0;
 907         for_each_child_of_node(child, gchild) {
 908                 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
 909                                                       tz->trips, tz->ntrips);
 910                 if (ret)
 911                         goto free_tbps;
 912         }
 913
 914 finish:
 915         of_node_put(child);
 916         tz->mode = THERMAL_DEVICE_DISABLED;
 917
 918         return tz;
 919
 920 free_tbps:
 921         for (i = i - 1; i >= 0; i--)
 922                 of_node_put(tz->tbps[i].cooling_device);
 923         kfree(tz->tbps);
 924 free_trips:
 925         for (i = 0; i < tz->ntrips; i++)
 926                 of_node_put(tz->trips[i].np);
 927         kfree(tz->trips);
 928         of_node_put(gchild);
 929 free_tz:
 930         kfree(tz);
 931         of_node_put(child);
 932
 933         return ERR_PTR(ret);
 934 }
 935
 936 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
 937 {
 938         int i;
 939
 940         for (i = 0; i < tz->num_tbps; i++)
 941                 of_node_put(tz->tbps[i].cooling_device);
 942         kfree(tz->tbps);
 943         for (i = 0; i < tz->ntrips; i++)
 944                 of_node_put(tz->trips[i].np);
 945         kfree(tz->trips);
 946         kfree(tz);
 947 }
 948
 949 /**
 950  * of_parse_thermal_zones - parse device tree thermal data
 951  *
 952  * Initialization function that can be called by machine initialization
 953  * code to parse thermal data and populate the thermal framework
 954  * with hardware thermal zones info. This function only parses thermal zones.
 955  * Cooling devices and sensor devices nodes are supposed to be parsed
 956  * by their respective drivers.
 957  *
 958  * Return: 0 on success, proper error code otherwise
 959  *
 960  */
 961 int __init of_parse_thermal_zones(void)
 962 {
 963         struct device_node *np, *child;
 964         struct __thermal_zone *tz;
 965         struct thermal_zone_device_ops *ops;
 966
 967         np = of_find_node_by_name(NULL, "thermal-zones");
 968         if (!np) {
 969                 pr_debug("unable to find thermal zones\n");
 970                 return 0; /* Run successfully on systems without thermal DT */
 971         }
 972
 973         for_each_available_child_of_node(np, child) {
 974                 struct thermal_zone_device *zone;
 975                 struct thermal_zone_params *tzp;
 976                 int i, mask = 0;
 977                 u32 prop;
 978
 979                 tz = thermal_of_build_thermal_zone(child);
 980                 if (IS_ERR(tz)) {
 981                         pr_err("failed to build thermal zone %s: %ld\n",
 982                                child->name,
 983                                PTR_ERR(tz));
 984                         continue;
 985                 }
 986
 987                 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
 988                 if (!ops)
 989                         goto exit_free;
 990
 991                 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
 992                 if (!tzp) {
 993                         kfree(ops);
 994                         goto exit_free;
 995                 }
 996
 997                 /* No hwmon because there might be hwmon drivers registering */
 998                 tzp->no_hwmon = true;
 999
1000                 if (!of_property_read_u32(child, "sustainable-power", &prop))
1001                         tzp->sustainable_power = prop;
1002
1003                 for (i = 0; i < tz->ntrips; i++)
1004                         mask |= 1 << i;
1005
1006                 /* these two are left for temperature drivers to use */
1007                 tzp->slope = tz->slope;
1008                 tzp->offset = tz->offset;
1009
1010                 zone = thermal_zone_device_register(child->name, tz->ntrips,
1011                                                     mask, tz,
1012                                                     ops, tzp,
1013                                                     tz->passive_delay,
1014                                                     tz->polling_delay);
1015                 if (IS_ERR(zone)) {
1016                         pr_err("Failed to build %s zone %ld\n", child->name,
1017                                PTR_ERR(zone));
1018                         kfree(tzp);
1019                         kfree(ops);
1020                         of_thermal_free_zone(tz);
1021                         /* attempting to build remaining zones still */
1022                 }
1023         }
1024         of_node_put(np);
1025
1026         return 0;
1027
1028 exit_free:
1029         of_node_put(child);
1030         of_node_put(np);
1031         of_thermal_free_zone(tz);
1032
1033         /* no memory available, so free what we have built */
1034         of_thermal_destroy_zones();
1035
1036         return -ENOMEM;
1037 }
1038
1039 /**
1040  * of_thermal_destroy_zones - remove all zones parsed and allocated resources
1041  *
1042  * Finds all zones parsed and added to the thermal framework and remove them
1043  * from the system, together with their resources.
1044  *
1045  */
1046 void of_thermal_destroy_zones(void)
1047 {
1048         struct device_node *np, *child;
1049
1050         np = of_find_node_by_name(NULL, "thermal-zones");
1051         if (!np) {
1052                 pr_debug("unable to find thermal zones\n");
1053                 return;
1054         }
1055
1056         for_each_available_child_of_node(np, child) {
1057                 struct thermal_zone_device *zone;
1058
1059                 zone = thermal_zone_get_zone_by_name(child->name);
1060                 if (IS_ERR(zone))
1061                         continue;
1062
1063                 thermal_zone_device_unregister(zone);
1064                 kfree(zone->tzp);
1065                 kfree(zone->ops);
1066                 of_thermal_free_zone(zone->devdata);
1067         }
1068         of_node_put(np);
1069 }