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         /*
  82          * Check 'changed' here to avoid issues due to race between
  83          * power_supply_changed() and this routine. In worst case
  84          * power_supply_changed() can be called again just before we take above
  85          * lock. During the first call of this routine we will mark 'changed' as
  86          * false and it will stay false for the next call as well.
  87          */
  88         if (likely(psy->changed)) {
  89                 psy->changed = false;
  90                 spin_unlock_irqrestore(&psy->changed_lock, flags);
  91                 class_for_each_device(power_supply_class, NULL, psy,
  92                                       __power_supply_changed_work);
  93                 power_supply_update_leds(psy);
  94                 atomic_notifier_call_chain(&power_supply_notifier,
  95                                 PSY_EVENT_PROP_CHANGED, psy);
  96                 kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  97                 spin_lock_irqsave(&psy->changed_lock, flags);
  98         }
  99
 100         /*
 101          * Hold the wakeup_source until all events are processed.
 102          * power_supply_changed() might have called again and have set 'changed'
 103          * to true.
 104          */
 105         if (likely(!psy->changed))
 106                 pm_relax(psy->dev);
 107         spin_unlock_irqrestore(&psy->changed_lock, flags);
 108 }
 109
 110 void power_supply_changed(struct power_supply *psy)
 111 {
 112         unsigned long flags;
 113
 114         dev_dbg(psy->dev, "%s\n", __func__);
 115
 116         spin_lock_irqsave(&psy->changed_lock, flags);
 117         psy->changed = true;
 118         pm_stay_awake(psy->dev);
 119         spin_unlock_irqrestore(&psy->changed_lock, flags);
 120         schedule_work(&psy->changed_work);
 121 }
 122 EXPORT_SYMBOL_GPL(power_supply_changed);
 123
 124 #ifdef CONFIG_OF
 125 #include <linux/of.h>
 126
 127 static int __power_supply_populate_supplied_from(struct device *dev,
 128                                                  void *data)
 129 {
 130         struct power_supply *psy = data;
 131         struct power_supply *epsy = dev_get_drvdata(dev);
 132         struct device_node *np;
 133         int i = 0;
 134
 135         do {
 136                 np = of_parse_phandle(psy->of_node, "power-supplies", i++);
 137                 if (!np)
 138                         break;
 139
 140                 if (np == epsy->of_node) {
 141                         dev_info(psy->dev, "%s: Found supply : %s\n",
 142                                 psy->name, epsy->name);
 143                         psy->supplied_from[i-1] = (char *)epsy->name;
 144                         psy->num_supplies++;
 145                         of_node_put(np);
 146                         break;
 147                 }
 148                 of_node_put(np);
 149         } while (np);
 150
 151         return 0;
 152 }
 153
 154 static int power_supply_populate_supplied_from(struct power_supply *psy)
 155 {
 156         int error;
 157
 158         error = class_for_each_device(power_supply_class, NULL, psy,
 159                                       __power_supply_populate_supplied_from);
 160
 161         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 162
 163         return error;
 164 }
 165
 166 static int  __power_supply_find_supply_from_node(struct device *dev,
 167                                                  void *data)
 168 {
 169         struct device_node *np = data;
 170         struct power_supply *epsy = dev_get_drvdata(dev);
 171
 172         /* returning non-zero breaks out of class_for_each_device loop */
 173         if (epsy->of_node == np)
 174                 return 1;
 175
 176         return 0;
 177 }
 178
 179 static int power_supply_find_supply_from_node(struct device_node *supply_node)
 180 {
 181         int error;
 182         struct device *dev;
 183         struct class_dev_iter iter;
 184
 185         /*
 186          * Use iterator to see if any other device is registered.
 187          * This is required since class_for_each_device returns 0
 188          * if there are no devices registered.
 189          */
 190         class_dev_iter_init(&iter, power_supply_class, NULL, NULL);
 191         dev = class_dev_iter_next(&iter);
 192
 193         if (!dev)
 194                 return -EPROBE_DEFER;
 195
 196         /*
 197          * class_for_each_device() either returns its own errors or values
 198          * returned by __power_supply_find_supply_from_node().
 199          *
 200          * __power_supply_find_supply_from_node() will return 0 (no match)
 201          * or 1 (match).
 202          *
 203          * We return 0 if class_for_each_device() returned 1, -EPROBE_DEFER if
 204          * it returned 0, or error as returned by it.
 205          */
 206         error = class_for_each_device(power_supply_class, NULL, supply_node,
 207                                        __power_supply_find_supply_from_node);
 208
 209         return error ? (error == 1 ? 0 : error) : -EPROBE_DEFER;
 210 }
 211
 212 static int power_supply_check_supplies(struct power_supply *psy)
 213 {
 214         struct device_node *np;
 215         int cnt = 0;
 216
 217         /* If there is already a list honor it */
 218         if (psy->supplied_from && psy->num_supplies > 0)
 219                 return 0;
 220
 221         /* No device node found, nothing to do */
 222         if (!psy->of_node)
 223                 return 0;
 224
 225         do {
 226                 int ret;
 227
 228                 np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
 229                 if (!np)
 230                         break;
 231
 232                 ret = power_supply_find_supply_from_node(np);
 233                 of_node_put(np);
 234
 235                 if (ret) {
 236                         dev_dbg(psy->dev, "Failed to find supply!\n");
 237                         return ret;
 238                 }
 239         } while (np);
 240
 241         /* Missing valid "power-supplies" entries */
 242         if (cnt == 1)
 243                 return 0;
 244
 245         /* All supplies found, allocate char ** array for filling */
 246         psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from),
 247                                           GFP_KERNEL);
 248         if (!psy->supplied_from) {
 249                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 250                 return -ENOMEM;
 251         }
 252
 253         *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * (cnt - 1),
 254                                            GFP_KERNEL);
 255         if (!*psy->supplied_from) {
 256                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 257                 return -ENOMEM;
 258         }
 259
 260         return power_supply_populate_supplied_from(psy);
 261 }
 262 #else
 263 static inline int power_supply_check_supplies(struct power_supply *psy)
 264 {
 265         return 0;
 266 }
 267 #endif
 268
 269 static int __power_supply_am_i_supplied(struct device *dev, void *data)
 270 {
 271         union power_supply_propval ret = {0,};
 272         struct power_supply *psy = data;
 273         struct power_supply *epsy = dev_get_drvdata(dev);
 274
 275         if (__power_supply_is_supplied_by(epsy, psy))
 276                 if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret))
 277                         return ret.intval;
 278
 279         return 0;
 280 }
 281
 282 int power_supply_am_i_supplied(struct power_supply *psy)
 283 {
 284         int error;
 285
 286         error = class_for_each_device(power_supply_class, NULL, psy,
 287                                       __power_supply_am_i_supplied);
 288
 289         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 290
 291         return error;
 292 }
 293 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 294
 295 static int __power_supply_is_system_supplied(struct device *dev, void *data)
 296 {
 297         union power_supply_propval ret = {0,};
 298         struct power_supply *psy = dev_get_drvdata(dev);
 299         unsigned int *count = data;
 300
 301         (*count)++;
 302         if (psy->type != POWER_SUPPLY_TYPE_BATTERY)
 303                 if (!psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 304                         return ret.intval;
 305
 306         return 0;
 307 }
 308
 309 int power_supply_is_system_supplied(void)
 310 {
 311         int error;
 312         unsigned int count = 0;
 313
 314         error = class_for_each_device(power_supply_class, NULL, &count,
 315                                       __power_supply_is_system_supplied);
 316
 317         /*
 318          * If no power class device was found at all, most probably we are
 319          * running on a desktop system, so assume we are on mains power.
 320          */
 321         if (count == 0)
 322                 return 1;
 323
 324         return error;
 325 }
 326 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 327
 328 int power_supply_set_battery_charged(struct power_supply *psy)
 329 {
 330         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 331                 psy->set_charged(psy);
 332                 return 0;
 333         }
 334
 335         return -EINVAL;
 336 }
 337 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 338
 339 static int power_supply_match_device_by_name(struct device *dev, const void *data)
 340 {
 341         const char *name = data;
 342         struct power_supply *psy = dev_get_drvdata(dev);
 343
 344         return strcmp(psy->name, name) == 0;
 345 }
 346
 347 struct power_supply *power_supply_get_by_name(const char *name)
 348 {
 349         struct device *dev = class_find_device(power_supply_class, NULL, name,
 350                                         power_supply_match_device_by_name);
 351
 352         return dev ? dev_get_drvdata(dev) : NULL;
 353 }
 354 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 355
 356 #ifdef CONFIG_OF
 357 static int power_supply_match_device_node(struct device *dev, const void *data)
 358 {
 359         return dev->parent && dev->parent->of_node == data;
 360 }
 361
 362 struct power_supply *power_supply_get_by_phandle(struct device_node *np,
 363                                                         const char *property)
 364 {
 365         struct device_node *power_supply_np;
 366         struct device *dev;
 367
 368         power_supply_np = of_parse_phandle(np, property, 0);
 369         if (!power_supply_np)
 370                 return ERR_PTR(-ENODEV);
 371
 372         dev = class_find_device(power_supply_class, NULL, power_supply_np,
 373                                                 power_supply_match_device_node);
 374
 375         of_node_put(power_supply_np);
 376
 377         return dev ? dev_get_drvdata(dev) : NULL;
 378 }
 379 EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
 380 #endif /* CONFIG_OF */
 381
 382 int power_supply_powers(struct power_supply *psy, struct device *dev)
 383 {
 384         return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 385 }
 386 EXPORT_SYMBOL_GPL(power_supply_powers);
 387
 388 static void power_supply_dev_release(struct device *dev)
 389 {
 390         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 391         kfree(dev);
 392 }
 393
 394 int power_supply_reg_notifier(struct notifier_block *nb)
 395 {
 396         return atomic_notifier_chain_register(&power_supply_notifier, nb);
 397 }
 398 EXPORT_SYMBOL_GPL(power_supply_reg_notifier);
 399
 400 void power_supply_unreg_notifier(struct notifier_block *nb)
 401 {
 402         atomic_notifier_chain_unregister(&power_supply_notifier, nb);
 403 }
 404 EXPORT_SYMBOL_GPL(power_supply_unreg_notifier);
 405
 406 #ifdef CONFIG_THERMAL
 407 static int power_supply_read_temp(struct thermal_zone_device *tzd,
 408                 unsigned long *temp)
 409 {
 410         struct power_supply *psy;
 411         union power_supply_propval val;
 412         int ret;
 413
 414         WARN_ON(tzd == NULL);
 415         psy = tzd->devdata;
 416         ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
 417
 418         /* Convert tenths of degree Celsius to milli degree Celsius. */
 419         if (!ret)
 420                 *temp = val.intval * 100;
 421
 422         return ret;
 423 }
 424
 425 static struct thermal_zone_device_ops psy_tzd_ops = {
 426         .get_temp = power_supply_read_temp,
 427 };
 428
 429 static int psy_register_thermal(struct power_supply *psy)
 430 {
 431         int i;
 432
 433         /* Register battery zone device psy reports temperature */
 434         for (i = 0; i < psy->num_properties; i++) {
 435                 if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
 436                         psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
 437                                         psy, &psy_tzd_ops, NULL, 0, 0);
 438                         return PTR_ERR_OR_ZERO(psy->tzd);
 439                 }
 440         }
 441         return 0;
 442 }
 443
 444 static void psy_unregister_thermal(struct power_supply *psy)
 445 {
 446         if (IS_ERR_OR_NULL(psy->tzd))
 447                 return;
 448         thermal_zone_device_unregister(psy->tzd);
 449 }
 450
 451 /* thermal cooling device callbacks */
 452 static int ps_get_max_charge_cntl_limit(struct thermal_cooling_device *tcd,
 453                                         unsigned long *state)
 454 {
 455         struct power_supply *psy;
 456         union power_supply_propval val;
 457         int ret;
 458
 459         psy = tcd->devdata;
 460         ret = psy->get_property(psy,
 461                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX, &val);
 462         if (!ret)
 463                 *state = val.intval;
 464
 465         return ret;
 466 }
 467
 468 static int ps_get_cur_chrage_cntl_limit(struct thermal_cooling_device *tcd,
 469                                         unsigned long *state)
 470 {
 471         struct power_supply *psy;
 472         union power_supply_propval val;
 473         int ret;
 474
 475         psy = tcd->devdata;
 476         ret = psy->get_property(psy,
 477                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
 478         if (!ret)
 479                 *state = val.intval;
 480
 481         return ret;
 482 }
 483
 484 static int ps_set_cur_charge_cntl_limit(struct thermal_cooling_device *tcd,
 485                                         unsigned long state)
 486 {
 487         struct power_supply *psy;
 488         union power_supply_propval val;
 489         int ret;
 490
 491         psy = tcd->devdata;
 492         val.intval = state;
 493         ret = psy->set_property(psy,
 494                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
 495
 496         return ret;
 497 }
 498
 499 static struct thermal_cooling_device_ops psy_tcd_ops = {
 500         .get_max_state = ps_get_max_charge_cntl_limit,
 501         .get_cur_state = ps_get_cur_chrage_cntl_limit,
 502         .set_cur_state = ps_set_cur_charge_cntl_limit,
 503 };
 504
 505 static int psy_register_cooler(struct power_supply *psy)
 506 {
 507         int i;
 508
 509         /* Register for cooling device if psy can control charging */
 510         for (i = 0; i < psy->num_properties; i++) {
 511                 if (psy->properties[i] ==
 512                                 POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT) {
 513                         psy->tcd = thermal_cooling_device_register(
 514                                                         (char *)psy->name,
 515                                                         psy, &psy_tcd_ops);
 516                         return PTR_ERR_OR_ZERO(psy->tcd);
 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");