linux/drivers/power/power_supply_core.c
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   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 */
  24struct class *power_supply_class;
  25EXPORT_SYMBOL_GPL(power_supply_class);
  26
  27static struct device_type power_supply_dev_type;
  28
  29static 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
  55static 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
  68static 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
  83void power_supply_changed(struct power_supply *psy)
  84{
  85        dev_dbg(psy->dev, "%s\n", __func__);
  86
  87        schedule_work(&psy->changed_work);
  88}
  89EXPORT_SYMBOL_GPL(power_supply_changed);
  90
  91#ifdef CONFIG_OF
  92#include <linux/of.h>
  93
  94static 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
 121static 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
 133static 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
 146static 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
 175static 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
 222static inline int power_supply_check_supplies(struct power_supply *psy)
 223{
 224        return 0;
 225}
 226#endif
 227
 228static 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
 243int 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}
 254EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 255
 256static 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
 272int 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}
 289EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 290
 291int 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}
 300EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 301
 302static 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
 310struct 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}
 317EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 318
 319int power_supply_powers(struct power_supply *psy, struct device *dev)
 320{
 321        return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 322}
 323EXPORT_SYMBOL_GPL(power_supply_powers);
 324
 325static 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
 332static 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
 350static struct thermal_zone_device_ops psy_tzd_ops = {
 351        .get_temp = power_supply_read_temp,
 352};
 353
 354static 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
 371static 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 */
 379static 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
 395static 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
 411static 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
 426static 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
 432static 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
 451static 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
 458static int psy_register_thermal(struct power_supply *psy)
 459{
 460        return 0;
 461}
 462
 463static void psy_unregister_thermal(struct power_supply *psy)
 464{
 465}
 466
 467static int psy_register_cooler(struct power_supply *psy)
 468{
 469        return 0;
 470}
 471
 472static void psy_unregister_cooler(struct power_supply *psy)
 473{
 474}
 475#endif
 476
 477int 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
 527create_triggers_failed:
 528        psy_unregister_cooler(psy);
 529register_cooler_failed:
 530        psy_unregister_thermal(psy);
 531register_thermal_failed:
 532        device_del(dev);
 533kobject_set_name_failed:
 534device_add_failed:
 535check_supplies_failed:
 536        put_device(dev);
 537success:
 538        return rc;
 539}
 540EXPORT_SYMBOL_GPL(power_supply_register);
 541
 542void 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}
 551EXPORT_SYMBOL_GPL(power_supply_unregister);
 552
 553static 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
 566static void __exit power_supply_class_exit(void)
 567{
 568        class_destroy(power_supply_class);
 569}
 570
 571subsys_initcall(power_supply_class_init);
 572module_exit(power_supply_class_exit);
 573
 574MODULE_DESCRIPTION("Universal power supply monitor class");
 575MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 576              "Szabolcs Gyurko, "
 577              "Anton Vorontsov <cbou@mail.ru>");
 578MODULE_LICENSE("GPL");
 579
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