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 int __power_supply_changed_work(struct device *dev, void *data)
  30{
  31        struct power_supply *psy = (struct power_supply *)data;
  32        struct power_supply *pst = dev_get_drvdata(dev);
  33        int i;
  34
  35        for (i = 0; i < psy->num_supplicants; i++)
  36                if (!strcmp(psy->supplied_to[i], pst->name)) {
  37                        if (pst->external_power_changed)
  38                                pst->external_power_changed(pst);
  39                }
  40        return 0;
  41}
  42
  43static void power_supply_changed_work(struct work_struct *work)
  44{
  45        struct power_supply *psy = container_of(work, struct power_supply,
  46                                                changed_work);
  47
  48        dev_dbg(psy->dev, "%s\n", __func__);
  49
  50        class_for_each_device(power_supply_class, NULL, psy,
  51                              __power_supply_changed_work);
  52
  53        power_supply_update_leds(psy);
  54
  55        kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  56}
  57
  58void power_supply_changed(struct power_supply *psy)
  59{
  60        dev_dbg(psy->dev, "%s\n", __func__);
  61
  62        schedule_work(&psy->changed_work);
  63}
  64EXPORT_SYMBOL_GPL(power_supply_changed);
  65
  66static int __power_supply_am_i_supplied(struct device *dev, void *data)
  67{
  68        union power_supply_propval ret = {0,};
  69        struct power_supply *psy = (struct power_supply *)data;
  70        struct power_supply *epsy = dev_get_drvdata(dev);
  71        int i;
  72
  73        for (i = 0; i < epsy->num_supplicants; i++) {
  74                if (!strcmp(epsy->supplied_to[i], psy->name)) {
  75                        if (epsy->get_property(epsy,
  76                                  POWER_SUPPLY_PROP_ONLINE, &ret))
  77                                continue;
  78                        if (ret.intval)
  79                                return ret.intval;
  80                }
  81        }
  82        return 0;
  83}
  84
  85int power_supply_am_i_supplied(struct power_supply *psy)
  86{
  87        int error;
  88
  89        error = class_for_each_device(power_supply_class, NULL, psy,
  90                                      __power_supply_am_i_supplied);
  91
  92        dev_dbg(psy->dev, "%s %d\n", __func__, error);
  93
  94        return error;
  95}
  96EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
  97
  98static int __power_supply_is_system_supplied(struct device *dev, void *data)
  99{
 100        union power_supply_propval ret = {0,};
 101        struct power_supply *psy = dev_get_drvdata(dev);
 102        unsigned int *count = data;
 103
 104        (*count)++;
 105        if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 106                if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 107                        return 0;
 108                if (ret.intval)
 109                        return ret.intval;
 110        }
 111        return 0;
 112}
 113
 114int power_supply_is_system_supplied(void)
 115{
 116        int error;
 117        unsigned int count = 0;
 118
 119        error = class_for_each_device(power_supply_class, NULL, &count,
 120                                      __power_supply_is_system_supplied);
 121
 122        /*
 123         * If no power class device was found at all, most probably we are
 124         * running on a desktop system, so assume we are on mains power.
 125         */
 126        if (count == 0)
 127                return 1;
 128
 129        return error;
 130}
 131EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 132
 133int power_supply_set_battery_charged(struct power_supply *psy)
 134{
 135        if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 136                psy->set_charged(psy);
 137                return 0;
 138        }
 139
 140        return -EINVAL;
 141}
 142EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 143
 144static int power_supply_match_device_by_name(struct device *dev, void *data)
 145{
 146        const char *name = data;
 147        struct power_supply *psy = dev_get_drvdata(dev);
 148
 149        return strcmp(psy->name, name) == 0;
 150}
 151
 152struct power_supply *power_supply_get_by_name(char *name)
 153{
 154        struct device *dev = class_find_device(power_supply_class, NULL, name,
 155                                        power_supply_match_device_by_name);
 156
 157        return dev ? dev_get_drvdata(dev) : NULL;
 158}
 159EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 160
 161int power_supply_powers(struct power_supply *psy, struct device *dev)
 162{
 163        return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 164}
 165EXPORT_SYMBOL_GPL(power_supply_powers);
 166
 167static void power_supply_dev_release(struct device *dev)
 168{
 169        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 170        kfree(dev);
 171}
 172
 173#ifdef CONFIG_THERMAL
 174static int power_supply_read_temp(struct thermal_zone_device *tzd,
 175                unsigned long *temp)
 176{
 177        struct power_supply *psy;
 178        union power_supply_propval val;
 179        int ret;
 180
 181        WARN_ON(tzd == NULL);
 182        psy = tzd->devdata;
 183        ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
 184
 185        /* Convert tenths of degree Celsius to milli degree Celsius. */
 186        if (!ret)
 187                *temp = val.intval * 100;
 188
 189        return ret;
 190}
 191
 192static struct thermal_zone_device_ops psy_tzd_ops = {
 193        .get_temp = power_supply_read_temp,
 194};
 195
 196static int psy_register_thermal(struct power_supply *psy)
 197{
 198        int i;
 199
 200        /* Register battery zone device psy reports temperature */
 201        for (i = 0; i < psy->num_properties; i++) {
 202                if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
 203                        psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
 204                                        psy, &psy_tzd_ops, 0, 0);
 205                        if (IS_ERR(psy->tzd))
 206                                return PTR_ERR(psy->tzd);
 207                        break;
 208                }
 209        }
 210        return 0;
 211}
 212
 213static void psy_unregister_thermal(struct power_supply *psy)
 214{
 215        if (IS_ERR_OR_NULL(psy->tzd))
 216                return;
 217        thermal_zone_device_unregister(psy->tzd);
 218}
 219#else
 220static int psy_register_thermal(struct power_supply *psy)
 221{
 222        return 0;
 223}
 224
 225static void psy_unregister_thermal(struct power_supply *psy)
 226{
 227}
 228#endif
 229
 230int power_supply_register(struct device *parent, struct power_supply *psy)
 231{
 232        struct device *dev;
 233        int rc;
 234
 235        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 236        if (!dev)
 237                return -ENOMEM;
 238
 239        device_initialize(dev);
 240
 241        dev->class = power_supply_class;
 242        dev->type = &power_supply_dev_type;
 243        dev->parent = parent;
 244        dev->release = power_supply_dev_release;
 245        dev_set_drvdata(dev, psy);
 246        psy->dev = dev;
 247
 248        INIT_WORK(&psy->changed_work, power_supply_changed_work);
 249
 250        rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 251        if (rc)
 252                goto kobject_set_name_failed;
 253
 254        rc = device_add(dev);
 255        if (rc)
 256                goto device_add_failed;
 257
 258        rc = psy_register_thermal(psy);
 259        if (rc)
 260                goto register_thermal_failed;
 261
 262        rc = power_supply_create_triggers(psy);
 263        if (rc)
 264                goto create_triggers_failed;
 265
 266        power_supply_changed(psy);
 267
 268        goto success;
 269
 270create_triggers_failed:
 271        psy_unregister_thermal(psy);
 272register_thermal_failed:
 273        device_del(dev);
 274kobject_set_name_failed:
 275device_add_failed:
 276        put_device(dev);
 277success:
 278        return rc;
 279}
 280EXPORT_SYMBOL_GPL(power_supply_register);
 281
 282void power_supply_unregister(struct power_supply *psy)
 283{
 284        cancel_work_sync(&psy->changed_work);
 285        sysfs_remove_link(&psy->dev->kobj, "powers");
 286        power_supply_remove_triggers(psy);
 287        psy_unregister_thermal(psy);
 288        device_unregister(psy->dev);
 289}
 290EXPORT_SYMBOL_GPL(power_supply_unregister);
 291
 292static int __init power_supply_class_init(void)
 293{
 294        power_supply_class = class_create(THIS_MODULE, "power_supply");
 295
 296        if (IS_ERR(power_supply_class))
 297                return PTR_ERR(power_supply_class);
 298
 299        power_supply_class->dev_uevent = power_supply_uevent;
 300        power_supply_init_attrs(&power_supply_dev_type);
 301
 302        return 0;
 303}
 304
 305static void __exit power_supply_class_exit(void)
 306{
 307        class_destroy(power_supply_class);
 308}
 309
 310subsys_initcall(power_supply_class_init);
 311module_exit(power_supply_class_exit);
 312
 313MODULE_DESCRIPTION("Universal power supply monitor class");
 314MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 315              "Szabolcs Gyurko, "
 316              "Anton Vorontsov <cbou@mail.ru>");
 317MODULE_LICENSE("GPL");
 318
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