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