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