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 = (struct power_supply *)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 = (struct power_supply *)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                         continue;
 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 = (struct device_node *)data;
 162         struct power_supply *epsy = dev_get_drvdata(dev);
 163
 164         /* return error breaks out of class_for_each_device loop */
 165         if (epsy->of_node == np)
 166                 return -EINVAL;
 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          * We have to treat the return value as inverted, because if
 190          * we return error on not found, then it won't continue looking.
 191          * So we trick it by returning error on success to stop looking
 192          * once the matching device is found.
 193          */
 194         error = class_for_each_device(power_supply_class, NULL, supply_node,
 195                                        __power_supply_find_supply_from_node);
 196
 197         return error ? 0 : -EPROBE_DEFER;
 198 }
 199
 200 static int power_supply_check_supplies(struct power_supply *psy)
 201 {
 202         struct device_node *np;
 203         int cnt = 0;
 204
 205         /* If there is already a list honor it */
 206         if (psy->supplied_from && psy->num_supplies > 0)
 207                 return 0;
 208
 209         /* No device node found, nothing to do */
 210         if (!psy->of_node)
 211                 return 0;
 212
 213         do {
 214                 int ret;
 215
 216                 np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
 217                 if (!np)
 218                         continue;
 219
 220                 ret = power_supply_find_supply_from_node(np);
 221                 if (ret) {
 222                         dev_dbg(psy->dev, "Failed to find supply, defer!\n");
 223                         of_node_put(np);
 224                         return -EPROBE_DEFER;
 225                 }
 226                 of_node_put(np);
 227         } while (np);
 228
 229         /* All supplies found, allocate char ** array for filling */
 230         psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from),
 231                                           GFP_KERNEL);
 232         if (!psy->supplied_from) {
 233                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 234                 return -ENOMEM;
 235         }
 236
 237         *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * cnt,
 238                                            GFP_KERNEL);
 239         if (!*psy->supplied_from) {
 240                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 241                 return -ENOMEM;
 242         }
 243
 244         return power_supply_populate_supplied_from(psy);
 245 }
 246 #else
 247 static inline int power_supply_check_supplies(struct power_supply *psy)
 248 {
 249         return 0;
 250 }
 251 #endif
 252
 253 static int __power_supply_am_i_supplied(struct device *dev, void *data)
 254 {
 255         union power_supply_propval ret = {0,};
 256         struct power_supply *psy = (struct power_supply *)data;
 257         struct power_supply *epsy = dev_get_drvdata(dev);
 258
 259         if (__power_supply_is_supplied_by(epsy, psy))
 260                 if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) {
 261                         if (ret.intval)
 262                                 return ret.intval;
 263                 }
 264
 265         return 0;
 266 }
 267
 268 int power_supply_am_i_supplied(struct power_supply *psy)
 269 {
 270         int error;
 271
 272         error = class_for_each_device(power_supply_class, NULL, psy,
 273                                       __power_supply_am_i_supplied);
 274
 275         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 276
 277         return error;
 278 }
 279 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 280
 281 static int __power_supply_is_system_supplied(struct device *dev, void *data)
 282 {
 283         union power_supply_propval ret = {0,};
 284         struct power_supply *psy = dev_get_drvdata(dev);
 285         unsigned int *count = data;
 286
 287         (*count)++;
 288         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 289                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 290                         return 0;
 291                 if (ret.intval)
 292                         return ret.intval;
 293         }
 294         return 0;
 295 }
 296
 297 int power_supply_is_system_supplied(void)
 298 {
 299         int error;
 300         unsigned int count = 0;
 301
 302         error = class_for_each_device(power_supply_class, NULL, &count,
 303                                       __power_supply_is_system_supplied);
 304
 305         /*
 306          * If no power class device was found at all, most probably we are
 307          * running on a desktop system, so assume we are on mains power.
 308          */
 309         if (count == 0)
 310                 return 1;
 311
 312         return error;
 313 }
 314 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 315
 316 int power_supply_set_battery_charged(struct power_supply *psy)
 317 {
 318         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 319                 psy->set_charged(psy);
 320                 return 0;
 321         }
 322
 323         return -EINVAL;
 324 }
 325 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 326
 327 static int power_supply_match_device_by_name(struct device *dev, const void *data)
 328 {
 329         const char *name = data;
 330         struct power_supply *psy = dev_get_drvdata(dev);
 331
 332         return strcmp(psy->name, name) == 0;
 333 }
 334
 335 struct power_supply *power_supply_get_by_name(const char *name)
 336 {
 337         struct device *dev = class_find_device(power_supply_class, NULL, name,
 338                                         power_supply_match_device_by_name);
 339
 340         return dev ? dev_get_drvdata(dev) : NULL;
 341 }
 342 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 343
 344 #ifdef CONFIG_OF
 345 static int power_supply_match_device_node(struct device *dev, const void *data)
 346 {
 347         return dev->parent && dev->parent->of_node == data;
 348 }
 349
 350 struct power_supply *power_supply_get_by_phandle(struct device_node *np,
 351                                                         const char *property)
 352 {
 353         struct device_node *power_supply_np;
 354         struct device *dev;
 355
 356         power_supply_np = of_parse_phandle(np, property, 0);
 357         if (!power_supply_np)
 358                 return ERR_PTR(-ENODEV);
 359
 360         dev = class_find_device(power_supply_class, NULL, power_supply_np,
 361                                                 power_supply_match_device_node);
 362
 363         of_node_put(power_supply_np);
 364
 365         return dev ? dev_get_drvdata(dev) : NULL;
 366 }
 367 EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
 368 #endif /* CONFIG_OF */
 369
 370 int power_supply_powers(struct power_supply *psy, struct device *dev)
 371 {
 372         return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 373 }
 374 EXPORT_SYMBOL_GPL(power_supply_powers);
 375
 376 static void power_supply_dev_release(struct device *dev)
 377 {
 378         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 379         kfree(dev);
 380 }
 381
 382 int power_supply_reg_notifier(struct notifier_block *nb)
 383 {
 384         return atomic_notifier_chain_register(&power_supply_notifier, nb);
 385 }
 386 EXPORT_SYMBOL_GPL(power_supply_reg_notifier);
 387
 388 void power_supply_unreg_notifier(struct notifier_block *nb)
 389 {
 390         atomic_notifier_chain_unregister(&power_supply_notifier, nb);
 391 }
 392 EXPORT_SYMBOL_GPL(power_supply_unreg_notifier);
 393
 394 #ifdef CONFIG_THERMAL
 395 static int power_supply_read_temp(struct thermal_zone_device *tzd,
 396                 unsigned long *temp)
 397 {
 398         struct power_supply *psy;
 399         union power_supply_propval val;
 400         int ret;
 401
 402         WARN_ON(tzd == NULL);
 403         psy = tzd->devdata;
 404         ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
 405
 406         /* Convert tenths of degree Celsius to milli degree Celsius. */
 407         if (!ret)
 408                 *temp = val.intval * 100;
 409
 410         return ret;
 411 }
 412
 413 static struct thermal_zone_device_ops psy_tzd_ops = {
 414         .get_temp = power_supply_read_temp,
 415 };
 416
 417 static int psy_register_thermal(struct power_supply *psy)
 418 {
 419         int i;
 420
 421         /* Register battery zone device psy reports temperature */
 422         for (i = 0; i < psy->num_properties; i++) {
 423                 if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
 424                         psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
 425                                         psy, &psy_tzd_ops, NULL, 0, 0);
 426                         if (IS_ERR(psy->tzd))
 427                                 return PTR_ERR(psy->tzd);
 428                         break;
 429                 }
 430         }
 431         return 0;
 432 }
 433
 434 static void psy_unregister_thermal(struct power_supply *psy)
 435 {
 436         if (IS_ERR_OR_NULL(psy->tzd))
 437                 return;
 438         thermal_zone_device_unregister(psy->tzd);
 439 }
 440
 441 /* thermal cooling device callbacks */
 442 static int ps_get_max_charge_cntl_limit(struct thermal_cooling_device *tcd,
 443                                         unsigned long *state)
 444 {
 445         struct power_supply *psy;
 446         union power_supply_propval val;
 447         int ret;
 448
 449         psy = tcd->devdata;
 450         ret = psy->get_property(psy,
 451                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX, &val);
 452         if (!ret)
 453                 *state = val.intval;
 454
 455         return ret;
 456 }
 457
 458 static int ps_get_cur_chrage_cntl_limit(struct thermal_cooling_device *tcd,
 459                                         unsigned long *state)
 460 {
 461         struct power_supply *psy;
 462         union power_supply_propval val;
 463         int ret;
 464
 465         psy = tcd->devdata;
 466         ret = psy->get_property(psy,
 467                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
 468         if (!ret)
 469                 *state = val.intval;
 470
 471         return ret;
 472 }
 473
 474 static int ps_set_cur_charge_cntl_limit(struct thermal_cooling_device *tcd,
 475                                         unsigned long state)
 476 {
 477         struct power_supply *psy;
 478         union power_supply_propval val;
 479         int ret;
 480
 481         psy = tcd->devdata;
 482         val.intval = state;
 483         ret = psy->set_property(psy,
 484                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
 485
 486         return ret;
 487 }
 488
 489 static struct thermal_cooling_device_ops psy_tcd_ops = {
 490         .get_max_state = ps_get_max_charge_cntl_limit,
 491         .get_cur_state = ps_get_cur_chrage_cntl_limit,
 492         .set_cur_state = ps_set_cur_charge_cntl_limit,
 493 };
 494
 495 static int psy_register_cooler(struct power_supply *psy)
 496 {
 497         int i;
 498
 499         /* Register for cooling device if psy can control charging */
 500         for (i = 0; i < psy->num_properties; i++) {
 501                 if (psy->properties[i] ==
 502                                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT) {
 503                         psy->tcd = thermal_cooling_device_register(
 504                                                         (char *)psy->name,
 505                                                         psy, &psy_tcd_ops);
 506                         if (IS_ERR(psy->tcd))
 507                                 return PTR_ERR(psy->tcd);
 508                         break;
 509                 }
 510         }
 511         return 0;
 512 }
 513
 514 static void psy_unregister_cooler(struct power_supply *psy)
 515 {
 516         if (IS_ERR_OR_NULL(psy->tcd))
 517                 return;
 518         thermal_cooling_device_unregister(psy->tcd);
 519 }
 520 #else
 521 static int psy_register_thermal(struct power_supply *psy)
 522 {
 523         return 0;
 524 }
 525
 526 static void psy_unregister_thermal(struct power_supply *psy)
 527 {
 528 }
 529
 530 static int psy_register_cooler(struct power_supply *psy)
 531 {
 532         return 0;
 533 }
 534
 535 static void psy_unregister_cooler(struct power_supply *psy)
 536 {
 537 }
 538 #endif
 539
 540 int power_supply_register(struct device *parent, struct power_supply *psy)
 541 {
 542         struct device *dev;
 543         int rc;
 544
 545         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 546         if (!dev)
 547                 return -ENOMEM;
 548
 549         device_initialize(dev);
 550
 551         dev->class = power_supply_class;
 552         dev->type = &power_supply_dev_type;
 553         dev->parent = parent;
 554         dev->release = power_supply_dev_release;
 555         dev_set_drvdata(dev, psy);
 556         psy->dev = dev;
 557
 558         rc = dev_set_name(dev, "%s", psy->name);
 559         if (rc)
 560                 goto dev_set_name_failed;
 561
 562         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 563
 564         rc = power_supply_check_supplies(psy);
 565         if (rc) {
 566                 dev_info(dev, "Not all required supplies found, defer probe\n");
 567                 goto check_supplies_failed;
 568         }
 569
 570         spin_lock_init(&psy->changed_lock);
 571         rc = device_init_wakeup(dev, true);
 572         if (rc)
 573                 goto wakeup_init_failed;
 574
 575         rc = device_add(dev);
 576         if (rc)
 577                 goto device_add_failed;
 578
 579         rc = psy_register_thermal(psy);
 580         if (rc)
 581                 goto register_thermal_failed;
 582
 583         rc = psy_register_cooler(psy);
 584         if (rc)
 585                 goto register_cooler_failed;
 586
 587         rc = power_supply_create_triggers(psy);
 588         if (rc)
 589                 goto create_triggers_failed;
 590
 591         power_supply_changed(psy);
 592
 593         goto success;
 594
 595 create_triggers_failed:
 596         psy_unregister_cooler(psy);
 597 register_cooler_failed:
 598         psy_unregister_thermal(psy);
 599 register_thermal_failed:
 600         device_del(dev);
 601 device_add_failed:
 602 wakeup_init_failed:
 603 check_supplies_failed:
 604 dev_set_name_failed:
 605         put_device(dev);
 606 success:
 607         return rc;
 608 }
 609 EXPORT_SYMBOL_GPL(power_supply_register);
 610
 611 void power_supply_unregister(struct power_supply *psy)
 612 {
 613         cancel_work_sync(&psy->changed_work);
 614         sysfs_remove_link(&psy->dev->kobj, "powers");
 615         power_supply_remove_triggers(psy);
 616         psy_unregister_cooler(psy);
 617         psy_unregister_thermal(psy);
 618         device_init_wakeup(psy->dev, false);
 619         device_unregister(psy->dev);
 620 }
 621 EXPORT_SYMBOL_GPL(power_supply_unregister);
 622
 623 static int __init power_supply_class_init(void)
 624 {
 625         power_supply_class = class_create(THIS_MODULE, "power_supply");
 626
 627         if (IS_ERR(power_supply_class))
 628                 return PTR_ERR(power_supply_class);
 629
 630         power_supply_class->dev_uevent = power_supply_uevent;
 631         power_supply_init_attrs(&power_supply_dev_type);
 632
 633         return 0;
 634 }
 635
 636 static void __exit power_supply_class_exit(void)
 637 {
 638         class_destroy(power_supply_class);
 639 }
 640
 641 subsys_initcall(power_supply_class_init);
 642 module_exit(power_supply_class_exit);
 643
 644 MODULE_DESCRIPTION("Universal power supply monitor class");
 645 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 646               "Szabolcs Gyurko, "
 647               "Anton Vorontsov <cbou@mail.ru>");
 648 MODULE_LICENSE("GPL");