drivers/power/power_supply_core.c

   1 /*
   2  *  Universal power supply monitor class
   3  *
   4  *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
   5  *  Copyright © 2004  Szabolcs Gyurko
   6  *  Copyright © 2003  Ian Molton <spyro@f2s.com>
   7  *
   8  *  Modified: 2004, Oct     Szabolcs Gyurko
   9  *
  10  *  You may use this code as per GPL version 2
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/device.h>
  18 #include <linux/notifier.h>
  19 #include <linux/err.h>
  20 #include <linux/power_supply.h>
  21 #include <linux/thermal.h>
  22 #include "power_supply.h"
  23
  24 /* exported for the APM Power driver, APM emulation */
  25 struct class *power_supply_class;
  26 EXPORT_SYMBOL_GPL(power_supply_class);
  27
  28 ATOMIC_NOTIFIER_HEAD(power_supply_notifier);
  29 EXPORT_SYMBOL_GPL(power_supply_notifier);
  30
  31 static struct device_type power_supply_dev_type;
  32
  33 static bool __power_supply_is_supplied_by(struct power_supply *supplier,
  34                                          struct power_supply *supply)
  35 {
  36         int i;
  37
  38         if (!supply->supplied_from && !supplier->supplied_to)
  39                 return false;
  40
  41         /* Support both supplied_to and supplied_from modes */
  42         if (supply->supplied_from) {
  43                 if (!supplier->name)
  44                         return false;
  45                 for (i = 0; i < supply->num_supplies; i++)
  46                         if (!strcmp(supplier->name, supply->supplied_from[i]))
  47                                 return true;
  48         } else {
  49                 if (!supply->name)
  50                         return false;
  51                 for (i = 0; i < supplier->num_supplicants; i++)
  52                         if (!strcmp(supplier->supplied_to[i], supply->name))
  53                                 return true;
  54         }
  55
  56         return false;
  57 }
  58
  59 static int __power_supply_changed_work(struct device *dev, void *data)
  60 {
  61         struct power_supply *psy = data;
  62         struct power_supply *pst = dev_get_drvdata(dev);
  63
  64         if (__power_supply_is_supplied_by(psy, pst)) {
  65                 if (pst->external_power_changed)
  66                         pst->external_power_changed(pst);
  67         }
  68
  69         return 0;
  70 }
  71
  72 static void power_supply_changed_work(struct work_struct *work)
  73 {
  74         unsigned long flags;
  75         struct power_supply *psy = container_of(work, struct power_supply,
  76                                                 changed_work);
  77
  78         dev_dbg(psy->dev, "%s\n", __func__);
  79
  80         spin_lock_irqsave(&psy->changed_lock, flags);
  81         if (psy->changed) {
  82                 psy->changed = false;
  83                 spin_unlock_irqrestore(&psy->changed_lock, flags);
  84                 class_for_each_device(power_supply_class, NULL, psy,
  85                                       __power_supply_changed_work);
  86                 power_supply_update_leds(psy);
  87                 atomic_notifier_call_chain(&power_supply_notifier,
  88                                 PSY_EVENT_PROP_CHANGED, psy);
  89                 kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  90                 spin_lock_irqsave(&psy->changed_lock, flags);
  91         }
  92         /*
  93          * Dependent power supplies (e.g. battery) may have changed state
  94          * as a result of this event, so poll again and hold the
  95          * wakeup_source until all events are processed.
  96          */
  97         if (!psy->changed)
  98                 pm_relax(psy->dev);
  99         spin_unlock_irqrestore(&psy->changed_lock, flags);
 100 }
 101
 102 void power_supply_changed(struct power_supply *psy)
 103 {
 104         unsigned long flags;
 105
 106         dev_dbg(psy->dev, "%s\n", __func__);
 107
 108         spin_lock_irqsave(&psy->changed_lock, flags);
 109         psy->changed = true;
 110         pm_stay_awake(psy->dev);
 111         spin_unlock_irqrestore(&psy->changed_lock, flags);
 112         schedule_work(&psy->changed_work);
 113 }
 114 EXPORT_SYMBOL_GPL(power_supply_changed);
 115
 116 #ifdef CONFIG_OF
 117 #include <linux/of.h>
 118
 119 static int __power_supply_populate_supplied_from(struct device *dev,
 120                                                  void *data)
 121 {
 122         struct power_supply *psy = data;
 123         struct power_supply *epsy = dev_get_drvdata(dev);
 124         struct device_node *np;
 125         int i = 0;
 126
 127         do {
 128                 np = of_parse_phandle(psy->of_node, "power-supplies", i++);
 129                 if (!np)
 130                         break;
 131
 132                 if (np == epsy->of_node) {
 133                         dev_info(psy->dev, "%s: Found supply : %s\n",
 134                                 psy->name, epsy->name);
 135                         psy->supplied_from[i-1] = (char *)epsy->name;
 136                         psy->num_supplies++;
 137                         of_node_put(np);
 138                         break;
 139                 }
 140                 of_node_put(np);
 141         } while (np);
 142
 143         return 0;
 144 }
 145
 146 static int power_supply_populate_supplied_from(struct power_supply *psy)
 147 {
 148         int error;
 149
 150         error = class_for_each_device(power_supply_class, NULL, psy,
 151                                       __power_supply_populate_supplied_from);
 152
 153         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 154
 155         return error;
 156 }
 157
 158 static int  __power_supply_find_supply_from_node(struct device *dev,
 159                                                  void *data)
 160 {
 161         struct device_node *np = data;
 162         struct power_supply *epsy = dev_get_drvdata(dev);
 163
 164         /* returning non-zero breaks out of class_for_each_device loop */
 165         if (epsy->of_node == np)
 166                 return 1;
 167
 168         return 0;
 169 }
 170
 171 static int power_supply_find_supply_from_node(struct device_node *supply_node)
 172 {
 173         int error;
 174         struct device *dev;
 175         struct class_dev_iter iter;
 176
 177         /*
 178          * Use iterator to see if any other device is registered.
 179          * This is required since class_for_each_device returns 0
 180          * if there are no devices registered.
 181          */
 182         class_dev_iter_init(&iter, power_supply_class, NULL, NULL);
 183         dev = class_dev_iter_next(&iter);
 184
 185         if (!dev)
 186                 return -EPROBE_DEFER;
 187
 188         /*
 189          * class_for_each_device() either returns its own errors or values
 190          * returned by __power_supply_find_supply_from_node().
 191          *
 192          * __power_supply_find_supply_from_node() will return 0 (no match)
 193          * or 1 (match).
 194          *
 195          * We return 0 if class_for_each_device() returned 1, -EPROBE_DEFER if
 196          * it returned 0, or error as returned by it.
 197          */
 198         error = class_for_each_device(power_supply_class, NULL, supply_node,
 199                                        __power_supply_find_supply_from_node);
 200
 201         return error ? (error == 1 ? 0 : error) : -EPROBE_DEFER;
 202 }
 203
 204 static int power_supply_check_supplies(struct power_supply *psy)
 205 {
 206         struct device_node *np;
 207         int cnt = 0;
 208
 209         /* If there is already a list honor it */
 210         if (psy->supplied_from && psy->num_supplies > 0)
 211                 return 0;
 212
 213         /* No device node found, nothing to do */
 214         if (!psy->of_node)
 215                 return 0;
 216
 217         do {
 218                 int ret;
 219
 220                 np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
 221                 if (!np)
 222                         break;
 223
 224                 ret = power_supply_find_supply_from_node(np);
 225                 of_node_put(np);
 226
 227                 if (ret) {
 228                         dev_dbg(psy->dev, "Failed to find supply!\n");
 229                         return ret;
 230                 }
 231         } while (np);
 232
 233         /* Missing valid "power-supplies" entries */
 234         if (cnt == 1)
 235                 return 0;
 236
 237         /* All supplies found, allocate char ** array for filling */
 238         psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from),
 239                                           GFP_KERNEL);
 240         if (!psy->supplied_from) {
 241                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 242                 return -ENOMEM;
 243         }
 244
 245         *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * (cnt - 1),
 246                                            GFP_KERNEL);
 247         if (!*psy->supplied_from) {
 248                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 249                 return -ENOMEM;
 250         }
 251
 252         return power_supply_populate_supplied_from(psy);
 253 }
 254 #else
 255 static inline int power_supply_check_supplies(struct power_supply *psy)
 256 {
 257         return 0;
 258 }
 259 #endif
 260
 261 static int __power_supply_am_i_supplied(struct device *dev, void *data)
 262 {
 263         union power_supply_propval ret = {0,};
 264         struct power_supply *psy = data;
 265         struct power_supply *epsy = dev_get_drvdata(dev);
 266
 267         if (__power_supply_is_supplied_by(epsy, psy))
 268                 if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) {
 269                         if (ret.intval)
 270                                 return ret.intval;
 271                 }
 272
 273         return 0;
 274 }
 275
 276 int power_supply_am_i_supplied(struct power_supply *psy)
 277 {
 278         int error;
 279
 280         error = class_for_each_device(power_supply_class, NULL, psy,
 281                                       __power_supply_am_i_supplied);
 282
 283         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 284
 285         return error;
 286 }
 287 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 288
 289 static int __power_supply_is_system_supplied(struct device *dev, void *data)
 290 {
 291         union power_supply_propval ret = {0,};
 292         struct power_supply *psy = dev_get_drvdata(dev);
 293         unsigned int *count = data;
 294
 295         (*count)++;
 296         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 297                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 298                         return 0;
 299                 if (ret.intval)
 300                         return ret.intval;
 301         }
 302         return 0;
 303 }
 304
 305 int power_supply_is_system_supplied(void)
 306 {
 307         int error;
 308         unsigned int count = 0;
 309
 310         error = class_for_each_device(power_supply_class, NULL, &count,
 311                                       __power_supply_is_system_supplied);
 312
 313         /*
 314          * If no power class device was found at all, most probably we are
 315          * running on a desktop system, so assume we are on mains power.
 316          */
 317         if (count == 0)
 318                 return 1;
 319
 320         return error;
 321 }
 322 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 323
 324 int power_supply_set_battery_charged(struct power_supply *psy)
 325 {
 326         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 327                 psy->set_charged(psy);
 328                 return 0;
 329         }
 330
 331         return -EINVAL;
 332 }
 333 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 334
 335 static int power_supply_match_device_by_name(struct device *dev, const void *data)
 336 {
 337         const char *name = data;
 338         struct power_supply *psy = dev_get_drvdata(dev);
 339
 340         return strcmp(psy->name, name) == 0;
 341 }
 342
 343 struct power_supply *power_supply_get_by_name(const char *name)
 344 {
 345         struct device *dev = class_find_device(power_supply_class, NULL, name,
 346                                         power_supply_match_device_by_name);
 347
 348         return dev ? dev_get_drvdata(dev) : NULL;
 349 }
 350 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 351
 352 #ifdef CONFIG_OF
 353 static int power_supply_match_device_node(struct device *dev, const void *data)
 354 {
 355         return dev->parent && dev->parent->of_node == data;
 356 }
 357
 358 struct power_supply *power_supply_get_by_phandle(struct device_node *np,
 359                                                         const char *property)
 360 {
 361         struct device_node *power_supply_np;
 362         struct device *dev;
 363
 364         power_supply_np = of_parse_phandle(np, property, 0);
 365         if (!power_supply_np)
 366                 return ERR_PTR(-ENODEV);
 367
 368         dev = class_find_device(power_supply_class, NULL, power_supply_np,
 369                                                 power_supply_match_device_node);
 370
 371         of_node_put(power_supply_np);
 372
 373         return dev ? dev_get_drvdata(dev) : NULL;
 374 }
 375 EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
 376 #endif /* CONFIG_OF */
 377
 378 int power_supply_powers(struct power_supply *psy, struct device *dev)
 379 {
 380         return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 381 }
 382 EXPORT_SYMBOL_GPL(power_supply_powers);
 383
 384 static void power_supply_dev_release(struct device *dev)
 385 {
 386         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 387         kfree(dev);
 388 }
 389
 390 int power_supply_reg_notifier(struct notifier_block *nb)
 391 {
 392         return atomic_notifier_chain_register(&power_supply_notifier, nb);
 393 }
 394 EXPORT_SYMBOL_GPL(power_supply_reg_notifier);
 395
 396 void power_supply_unreg_notifier(struct notifier_block *nb)
 397 {
 398         atomic_notifier_chain_unregister(&power_supply_notifier, nb);
 399 }
 400 EXPORT_SYMBOL_GPL(power_supply_unreg_notifier);
 401
 402 #ifdef CONFIG_THERMAL
 403 static int power_supply_read_temp(struct thermal_zone_device *tzd,
 404                 unsigned long *temp)
 405 {
 406         struct power_supply *psy;
 407         union power_supply_propval val;
 408         int ret;
 409
 410         WARN_ON(tzd == NULL);
 411         psy = tzd->devdata;
 412         ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
 413
 414         /* Convert tenths of degree Celsius to milli degree Celsius. */
 415         if (!ret)
 416                 *temp = val.intval * 100;
 417
 418         return ret;
 419 }
 420
 421 static struct thermal_zone_device_ops psy_tzd_ops = {
 422         .get_temp = power_supply_read_temp,
 423 };
 424
 425 static int psy_register_thermal(struct power_supply *psy)
 426 {
 427         int i;
 428
 429         /* Register battery zone device psy reports temperature */
 430         for (i = 0; i < psy->num_properties; i++) {
 431                 if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
 432                         psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
 433                                         psy, &psy_tzd_ops, NULL, 0, 0);
 434                         if (IS_ERR(psy->tzd))
 435                                 return PTR_ERR(psy->tzd);
 436                         break;
 437                 }
 438         }
 439         return 0;
 440 }
 441
 442 static void psy_unregister_thermal(struct power_supply *psy)
 443 {
 444         if (IS_ERR_OR_NULL(psy->tzd))
 445                 return;
 446         thermal_zone_device_unregister(psy->tzd);
 447 }
 448
 449 /* thermal cooling device callbacks */
 450 static int ps_get_max_charge_cntl_limit(struct thermal_cooling_device *tcd,
 451                                         unsigned long *state)
 452 {
 453         struct power_supply *psy;
 454         union power_supply_propval val;
 455         int ret;
 456
 457         psy = tcd->devdata;
 458         ret = psy->get_property(psy,
 459                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX, &val);
 460         if (!ret)
 461                 *state = val.intval;
 462
 463         return ret;
 464 }
 465
 466 static int ps_get_cur_chrage_cntl_limit(struct thermal_cooling_device *tcd,
 467                                         unsigned long *state)
 468 {
 469         struct power_supply *psy;
 470         union power_supply_propval val;
 471         int ret;
 472
 473         psy = tcd->devdata;
 474         ret = psy->get_property(psy,
 475                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
 476         if (!ret)
 477                 *state = val.intval;
 478
 479         return ret;
 480 }
 481
 482 static int ps_set_cur_charge_cntl_limit(struct thermal_cooling_device *tcd,
 483                                         unsigned long state)
 484 {
 485         struct power_supply *psy;
 486         union power_supply_propval val;
 487         int ret;
 488
 489         psy = tcd->devdata;
 490         val.intval = state;
 491         ret = psy->set_property(psy,
 492                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
 493
 494         return ret;
 495 }
 496
 497 static struct thermal_cooling_device_ops psy_tcd_ops = {
 498         .get_max_state = ps_get_max_charge_cntl_limit,
 499         .get_cur_state = ps_get_cur_chrage_cntl_limit,
 500         .set_cur_state = ps_set_cur_charge_cntl_limit,
 501 };
 502
 503 static int psy_register_cooler(struct power_supply *psy)
 504 {
 505         int i;
 506
 507         /* Register for cooling device if psy can control charging */
 508         for (i = 0; i < psy->num_properties; i++) {
 509                 if (psy->properties[i] ==
 510                                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT) {
 511                         psy->tcd = thermal_cooling_device_register(
 512                                                         (char *)psy->name,
 513                                                         psy, &psy_tcd_ops);
 514                         if (IS_ERR(psy->tcd))
 515                                 return PTR_ERR(psy->tcd);
 516                         break;
 517                 }
 518         }
 519         return 0;
 520 }
 521
 522 static void psy_unregister_cooler(struct power_supply *psy)
 523 {
 524         if (IS_ERR_OR_NULL(psy->tcd))
 525                 return;
 526         thermal_cooling_device_unregister(psy->tcd);
 527 }
 528 #else
 529 static int psy_register_thermal(struct power_supply *psy)
 530 {
 531         return 0;
 532 }
 533
 534 static void psy_unregister_thermal(struct power_supply *psy)
 535 {
 536 }
 537
 538 static int psy_register_cooler(struct power_supply *psy)
 539 {
 540         return 0;
 541 }
 542
 543 static void psy_unregister_cooler(struct power_supply *psy)
 544 {
 545 }
 546 #endif
 547
 548 static int __power_supply_register(struct device *parent,
 549                                    struct power_supply *psy, bool ws)
 550 {
 551         struct device *dev;
 552         int rc;
 553
 554         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 555         if (!dev)
 556                 return -ENOMEM;
 557
 558         device_initialize(dev);
 559
 560         dev->class = power_supply_class;
 561         dev->type = &power_supply_dev_type;
 562         dev->parent = parent;
 563         dev->release = power_supply_dev_release;
 564         dev_set_drvdata(dev, psy);
 565         psy->dev = dev;
 566
 567         rc = dev_set_name(dev, "%s", psy->name);
 568         if (rc)
 569                 goto dev_set_name_failed;
 570
 571         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 572
 573         rc = power_supply_check_supplies(psy);
 574         if (rc) {
 575                 dev_info(dev, "Not all required supplies found, defer probe\n");
 576                 goto check_supplies_failed;
 577         }
 578
 579         spin_lock_init(&psy->changed_lock);
 580         rc = device_init_wakeup(dev, ws);
 581         if (rc)
 582                 goto wakeup_init_failed;
 583
 584         rc = device_add(dev);
 585         if (rc)
 586                 goto device_add_failed;
 587
 588         rc = psy_register_thermal(psy);
 589         if (rc)
 590                 goto register_thermal_failed;
 591
 592         rc = psy_register_cooler(psy);
 593         if (rc)
 594                 goto register_cooler_failed;
 595
 596         rc = power_supply_create_triggers(psy);
 597         if (rc)
 598                 goto create_triggers_failed;
 599
 600         power_supply_changed(psy);
 601
 602         goto success;
 603
 604 create_triggers_failed:
 605         psy_unregister_cooler(psy);
 606 register_cooler_failed:
 607         psy_unregister_thermal(psy);
 608 register_thermal_failed:
 609         device_del(dev);
 610 device_add_failed:
 611 wakeup_init_failed:
 612 check_supplies_failed:
 613 dev_set_name_failed:
 614         put_device(dev);
 615 success:
 616         return rc;
 617 }
 618
 619 int power_supply_register(struct device *parent, struct power_supply *psy)
 620 {
 621         return __power_supply_register(parent, psy, true);
 622 }
 623 EXPORT_SYMBOL_GPL(power_supply_register);
 624
 625 int power_supply_register_no_ws(struct device *parent, struct power_supply *psy)
 626 {
 627         return __power_supply_register(parent, psy, false);
 628 }
 629 EXPORT_SYMBOL_GPL(power_supply_register_no_ws);
 630
 631 void power_supply_unregister(struct power_supply *psy)
 632 {
 633         cancel_work_sync(&psy->changed_work);
 634         sysfs_remove_link(&psy->dev->kobj, "powers");
 635         power_supply_remove_triggers(psy);
 636         psy_unregister_cooler(psy);
 637         psy_unregister_thermal(psy);
 638         device_init_wakeup(psy->dev, false);
 639         device_unregister(psy->dev);
 640 }
 641 EXPORT_SYMBOL_GPL(power_supply_unregister);
 642
 643 static int __init power_supply_class_init(void)
 644 {
 645         power_supply_class = class_create(THIS_MODULE, "power_supply");
 646
 647         if (IS_ERR(power_supply_class))
 648                 return PTR_ERR(power_supply_class);
 649
 650         power_supply_class->dev_uevent = power_supply_uevent;
 651         power_supply_init_attrs(&power_supply_dev_type);
 652
 653         return 0;
 654 }
 655
 656 static void __exit power_supply_class_exit(void)
 657 {
 658         class_destroy(power_supply_class);
 659 }
 660
 661 subsys_initcall(power_supply_class_init);
 662 module_exit(power_supply_class_exit);
 663
 664 MODULE_DESCRIPTION("Universal power supply monitor class");
 665 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 666               "Szabolcs Gyurko, "
 667               "Anton Vorontsov <cbou@mail.ru>");
 668 MODULE_LICENSE("GPL");