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
 183         /*
 184          * class_for_each_device() either returns its own errors or values
 185          * returned by __power_supply_find_supply_from_node().
 186          *
 187          * __power_supply_find_supply_from_node() will return 0 (no match)
 188          * or 1 (match).
 189          *
 190          * We return 0 if class_for_each_device() returned 1, -EPROBE_DEFER if
 191          * it returned 0, or error as returned by it.
 192          */
 193         error = class_for_each_device(power_supply_class, NULL, supply_node,
 194                                        __power_supply_find_supply_from_node);
 195
 196         return error ? (error == 1 ? 0 : error) : -EPROBE_DEFER;
 197 }
 198
 199 static int power_supply_check_supplies(struct power_supply *psy)
 200 {
 201         struct device_node *np;
 202         int cnt = 0;
 203
 204         /* If there is already a list honor it */
 205         if (psy->supplied_from && psy->num_supplies > 0)
 206                 return 0;
 207
 208         /* No device node found, nothing to do */
 209         if (!psy->of_node)
 210                 return 0;
 211
 212         do {
 213                 int ret;
 214
 215                 np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
 216                 if (!np)
 217                         break;
 218
 219                 ret = power_supply_find_supply_from_node(np);
 220                 of_node_put(np);
 221
 222                 if (ret) {
 223                         dev_dbg(psy->dev, "Failed to find supply!\n");
 224                         return ret;
 225                 }
 226         } while (np);
 227
 228         /* Missing valid "power-supplies" entries */
 229         if (cnt == 1)
 230                 return 0;
 231
 232         /* All supplies found, allocate char ** array for filling */
 233         psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from),
 234                                           GFP_KERNEL);
 235         if (!psy->supplied_from) {
 236                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 237                 return -ENOMEM;
 238         }
 239
 240         *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * (cnt - 1),
 241                                            GFP_KERNEL);
 242         if (!*psy->supplied_from) {
 243                 dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
 244                 return -ENOMEM;
 245         }
 246
 247         return power_supply_populate_supplied_from(psy);
 248 }
 249 #else
 250 static inline int power_supply_check_supplies(struct power_supply *psy)
 251 {
 252         return 0;
 253 }
 254 #endif
 255
 256 static int __power_supply_am_i_supplied(struct device *dev, void *data)
 257 {
 258         union power_supply_propval ret = {0,};
 259         struct power_supply *psy = data;
 260         struct power_supply *epsy = dev_get_drvdata(dev);
 261
 262         if (__power_supply_is_supplied_by(epsy, psy))
 263                 if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret))
 264                         return ret.intval;
 265
 266         return 0;
 267 }
 268
 269 int power_supply_am_i_supplied(struct power_supply *psy)
 270 {
 271         int error;
 272
 273         error = class_for_each_device(power_supply_class, NULL, psy,
 274                                       __power_supply_am_i_supplied);
 275
 276         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 277
 278         return error;
 279 }
 280 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 281
 282 static int __power_supply_is_system_supplied(struct device *dev, void *data)
 283 {
 284         union power_supply_propval ret = {0,};
 285         struct power_supply *psy = dev_get_drvdata(dev);
 286         unsigned int *count = data;
 287
 288         (*count)++;
 289         if (psy->type != POWER_SUPPLY_TYPE_BATTERY)
 290                 if (!psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 291                         return ret.intval;
 292
 293         return 0;
 294 }
 295
 296 int power_supply_is_system_supplied(void)
 297 {
 298         int error;
 299         unsigned int count = 0;
 300
 301         error = class_for_each_device(power_supply_class, NULL, &count,
 302                                       __power_supply_is_system_supplied);
 303
 304         /*
 305          * If no power class device was found at all, most probably we are
 306          * running on a desktop system, so assume we are on mains power.
 307          */
 308         if (count == 0)
 309                 return 1;
 310
 311         return error;
 312 }
 313 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 314
 315 int power_supply_set_battery_charged(struct power_supply *psy)
 316 {
 317         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 318                 psy->set_charged(psy);
 319                 return 0;
 320         }
 321
 322         return -EINVAL;
 323 }
 324 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 325
 326 static int power_supply_match_device_by_name(struct device *dev, const void *data)
 327 {
 328         const char *name = data;
 329         struct power_supply *psy = dev_get_drvdata(dev);
 330
 331         return strcmp(psy->name, name) == 0;
 332 }
 333
 334 struct power_supply *power_supply_get_by_name(const char *name)
 335 {
 336         struct device *dev = class_find_device(power_supply_class, NULL, name,
 337                                         power_supply_match_device_by_name);
 338
 339         return dev ? dev_get_drvdata(dev) : NULL;
 340 }
 341 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 342
 343 #ifdef CONFIG_OF
 344 static int power_supply_match_device_node(struct device *dev, const void *data)
 345 {
 346         return dev->parent && dev->parent->of_node == data;
 347 }
 348
 349 struct power_supply *power_supply_get_by_phandle(struct device_node *np,
 350                                                         const char *property)
 351 {
 352         struct device_node *power_supply_np;
 353         struct device *dev;
 354
 355         power_supply_np = of_parse_phandle(np, property, 0);
 356         if (!power_supply_np)
 357                 return ERR_PTR(-ENODEV);
 358
 359         dev = class_find_device(power_supply_class, NULL, power_supply_np,
 360                                                 power_supply_match_device_node);
 361
 362         of_node_put(power_supply_np);
 363
 364         return dev ? dev_get_drvdata(dev) : NULL;
 365 }
 366 EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
 367 #endif /* CONFIG_OF */
 368
 369 int power_supply_powers(struct power_supply *psy, struct device *dev)
 370 {
 371         return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 372 }
 373 EXPORT_SYMBOL_GPL(power_supply_powers);
 374
 375 static void power_supply_dev_release(struct device *dev)
 376 {
 377         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 378         kfree(dev);
 379 }
 380
 381 int power_supply_reg_notifier(struct notifier_block *nb)
 382 {
 383         return atomic_notifier_chain_register(&power_supply_notifier, nb);
 384 }
 385 EXPORT_SYMBOL_GPL(power_supply_reg_notifier);
 386
 387 void power_supply_unreg_notifier(struct notifier_block *nb)
 388 {
 389         atomic_notifier_chain_unregister(&power_supply_notifier, nb);
 390 }
 391 EXPORT_SYMBOL_GPL(power_supply_unreg_notifier);
 392
 393 #ifdef CONFIG_THERMAL
 394 static int power_supply_read_temp(struct thermal_zone_device *tzd,
 395                 unsigned long *temp)
 396 {
 397         struct power_supply *psy;
 398         union power_supply_propval val;
 399         int ret;
 400
 401         WARN_ON(tzd == NULL);
 402         psy = tzd->devdata;
 403         ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
 404
 405         /* Convert tenths of degree Celsius to milli degree Celsius. */
 406         if (!ret)
 407                 *temp = val.intval * 100;
 408
 409         return ret;
 410 }
 411
 412 static struct thermal_zone_device_ops psy_tzd_ops = {
 413         .get_temp = power_supply_read_temp,
 414 };
 415
 416 static int psy_register_thermal(struct power_supply *psy)
 417 {
 418         int i;
 419
 420         if (psy->no_thermal)
 421                 return 0;
 422
 423         /* Register battery zone device psy reports temperature */
 424         for (i = 0; i < psy->num_properties; i++) {
 425                 if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
 426                         psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
 427                                         psy, &psy_tzd_ops, NULL, 0, 0);
 428                         return PTR_ERR_OR_ZERO(psy->tzd);
 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                         return PTR_ERR_OR_ZERO(psy->tcd);
 507                 }
 508         }
 509         return 0;
 510 }
 511
 512 static void psy_unregister_cooler(struct power_supply *psy)
 513 {
 514         if (IS_ERR_OR_NULL(psy->tcd))
 515                 return;
 516         thermal_cooling_device_unregister(psy->tcd);
 517 }
 518 #else
 519 static int psy_register_thermal(struct power_supply *psy)
 520 {
 521         return 0;
 522 }
 523
 524 static void psy_unregister_thermal(struct power_supply *psy)
 525 {
 526 }
 527
 528 static int psy_register_cooler(struct power_supply *psy)
 529 {
 530         return 0;
 531 }
 532
 533 static void psy_unregister_cooler(struct power_supply *psy)
 534 {
 535 }
 536 #endif
 537
 538 static int __power_supply_register(struct device *parent,
 539                                    struct power_supply *psy, bool ws)
 540 {
 541         struct device *dev;
 542         int rc;
 543
 544         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 545         if (!dev)
 546                 return -ENOMEM;
 547
 548         device_initialize(dev);
 549
 550         dev->class = power_supply_class;
 551         dev->type = &power_supply_dev_type;
 552         dev->parent = parent;
 553         dev->release = power_supply_dev_release;
 554         dev_set_drvdata(dev, psy);
 555         psy->dev = dev;
 556
 557         rc = dev_set_name(dev, "%s", psy->name);
 558         if (rc)
 559                 goto dev_set_name_failed;
 560
 561         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 562
 563         rc = power_supply_check_supplies(psy);
 564         if (rc) {
 565                 dev_info(dev, "Not all required supplies found, defer probe\n");
 566                 goto check_supplies_failed;
 567         }
 568
 569         spin_lock_init(&psy->changed_lock);
 570         rc = device_init_wakeup(dev, ws);
 571         if (rc)
 572                 goto wakeup_init_failed;
 573
 574         rc = device_add(dev);
 575         if (rc)
 576                 goto device_add_failed;
 577
 578         rc = psy_register_thermal(psy);
 579         if (rc)
 580                 goto register_thermal_failed;
 581
 582         rc = psy_register_cooler(psy);
 583         if (rc)
 584                 goto register_cooler_failed;
 585
 586         rc = power_supply_create_triggers(psy);
 587         if (rc)
 588                 goto create_triggers_failed;
 589
 590         power_supply_changed(psy);
 591
 592         return 0;
 593
 594 create_triggers_failed:
 595         psy_unregister_cooler(psy);
 596 register_cooler_failed:
 597         psy_unregister_thermal(psy);
 598 register_thermal_failed:
 599         device_del(dev);
 600 device_add_failed:
 601 wakeup_init_failed:
 602 check_supplies_failed:
 603 dev_set_name_failed:
 604         put_device(dev);
 605         return rc;
 606 }
 607
 608 int power_supply_register(struct device *parent, struct power_supply *psy)
 609 {
 610         return __power_supply_register(parent, psy, true);
 611 }
 612 EXPORT_SYMBOL_GPL(power_supply_register);
 613
 614 int power_supply_register_no_ws(struct device *parent, struct power_supply *psy)
 615 {
 616         return __power_supply_register(parent, psy, false);
 617 }
 618 EXPORT_SYMBOL_GPL(power_supply_register_no_ws);
 619
 620 void power_supply_unregister(struct power_supply *psy)
 621 {
 622         cancel_work_sync(&psy->changed_work);
 623         sysfs_remove_link(&psy->dev->kobj, "powers");
 624         power_supply_remove_triggers(psy);
 625         psy_unregister_cooler(psy);
 626         psy_unregister_thermal(psy);
 627         device_init_wakeup(psy->dev, false);
 628         device_unregister(psy->dev);
 629 }
 630 EXPORT_SYMBOL_GPL(power_supply_unregister);
 631
 632 static int __init power_supply_class_init(void)
 633 {
 634         power_supply_class = class_create(THIS_MODULE, "power_supply");
 635
 636         if (IS_ERR(power_supply_class))
 637                 return PTR_ERR(power_supply_class);
 638
 639         power_supply_class->dev_uevent = power_supply_uevent;
 640         power_supply_init_attrs(&power_supply_dev_type);
 641
 642         return 0;
 643 }
 644
 645 static void __exit power_supply_class_exit(void)
 646 {
 647         class_destroy(power_supply_class);
 648 }
 649
 650 subsys_initcall(power_supply_class_init);
 651 module_exit(power_supply_class_exit);
 652
 653 MODULE_DESCRIPTION("Universal power supply monitor class");
 654 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 655               "Szabolcs Gyurko, "
 656               "Anton Vorontsov <cbou@mail.ru>");
 657 MODULE_LICENSE("GPL");