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