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