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 "power_supply.h"
  21
  22/* exported for the APM Power driver, APM emulation */
  23struct class *power_supply_class;
  24EXPORT_SYMBOL_GPL(power_supply_class);
  25
  26static struct device_type power_supply_dev_type;
  27
  28static int __power_supply_changed_work(struct device *dev, void *data)
  29{
  30        struct power_supply *psy = (struct power_supply *)data;
  31        struct power_supply *pst = dev_get_drvdata(dev);
  32        int i;
  33
  34        for (i = 0; i < psy->num_supplicants; i++)
  35                if (!strcmp(psy->supplied_to[i], pst->name)) {
  36                        if (pst->external_power_changed)
  37                                pst->external_power_changed(pst);
  38                }
  39        return 0;
  40}
  41
  42static void power_supply_changed_work(struct work_struct *work)
  43{
  44        struct power_supply *psy = container_of(work, struct power_supply,
  45                                                changed_work);
  46
  47        dev_dbg(psy->dev, "%s\n", __func__);
  48
  49        class_for_each_device(power_supply_class, NULL, psy,
  50                              __power_supply_changed_work);
  51
  52        power_supply_update_leds(psy);
  53
  54        kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  55}
  56
  57void power_supply_changed(struct power_supply *psy)
  58{
  59        dev_dbg(psy->dev, "%s\n", __func__);
  60
  61        schedule_work(&psy->changed_work);
  62}
  63EXPORT_SYMBOL_GPL(power_supply_changed);
  64
  65static int __power_supply_am_i_supplied(struct device *dev, void *data)
  66{
  67        union power_supply_propval ret = {0,};
  68        struct power_supply *psy = (struct power_supply *)data;
  69        struct power_supply *epsy = dev_get_drvdata(dev);
  70        int i;
  71
  72        for (i = 0; i < epsy->num_supplicants; i++) {
  73                if (!strcmp(epsy->supplied_to[i], psy->name)) {
  74                        if (epsy->get_property(epsy,
  75                                  POWER_SUPPLY_PROP_ONLINE, &ret))
  76                                continue;
  77                        if (ret.intval)
  78                                return ret.intval;
  79                }
  80        }
  81        return 0;
  82}
  83
  84int power_supply_am_i_supplied(struct power_supply *psy)
  85{
  86        int error;
  87
  88        error = class_for_each_device(power_supply_class, NULL, psy,
  89                                      __power_supply_am_i_supplied);
  90
  91        dev_dbg(psy->dev, "%s %d\n", __func__, error);
  92
  93        return error;
  94}
  95EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
  96
  97static int __power_supply_is_system_supplied(struct device *dev, void *data)
  98{
  99        union power_supply_propval ret = {0,};
 100        struct power_supply *psy = dev_get_drvdata(dev);
 101        unsigned int *count = data;
 102
 103        (*count)++;
 104        if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 105                if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 106                        return 0;
 107                if (ret.intval)
 108                        return ret.intval;
 109        }
 110        return 0;
 111}
 112
 113int power_supply_is_system_supplied(void)
 114{
 115        int error;
 116        unsigned int count = 0;
 117
 118        error = class_for_each_device(power_supply_class, NULL, &count,
 119                                      __power_supply_is_system_supplied);
 120
 121        /*
 122         * If no power class device was found at all, most probably we are
 123         * running on a desktop system, so assume we are on mains power.
 124         */
 125        if (count == 0)
 126                return 1;
 127
 128        return error;
 129}
 130EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 131
 132int power_supply_set_battery_charged(struct power_supply *psy)
 133{
 134        if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 135                psy->set_charged(psy);
 136                return 0;
 137        }
 138
 139        return -EINVAL;
 140}
 141EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 142
 143static int power_supply_match_device_by_name(struct device *dev, void *data)
 144{
 145        const char *name = data;
 146        struct power_supply *psy = dev_get_drvdata(dev);
 147
 148        return strcmp(psy->name, name) == 0;
 149}
 150
 151struct power_supply *power_supply_get_by_name(char *name)
 152{
 153        struct device *dev = class_find_device(power_supply_class, NULL, name,
 154                                        power_supply_match_device_by_name);
 155
 156        return dev ? dev_get_drvdata(dev) : NULL;
 157}
 158EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 159
 160int power_supply_powers(struct power_supply *psy, struct device *dev)
 161{
 162        return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 163}
 164EXPORT_SYMBOL_GPL(power_supply_powers);
 165
 166static void power_supply_dev_release(struct device *dev)
 167{
 168        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 169        kfree(dev);
 170}
 171
 172int power_supply_register(struct device *parent, struct power_supply *psy)
 173{
 174        struct device *dev;
 175        int rc;
 176
 177        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 178        if (!dev)
 179                return -ENOMEM;
 180
 181        device_initialize(dev);
 182
 183        dev->class = power_supply_class;
 184        dev->type = &power_supply_dev_type;
 185        dev->parent = parent;
 186        dev->release = power_supply_dev_release;
 187        dev_set_drvdata(dev, psy);
 188        psy->dev = dev;
 189
 190        INIT_WORK(&psy->changed_work, power_supply_changed_work);
 191
 192        rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 193        if (rc)
 194                goto kobject_set_name_failed;
 195
 196        rc = device_add(dev);
 197        if (rc)
 198                goto device_add_failed;
 199
 200        rc = power_supply_create_triggers(psy);
 201        if (rc)
 202                goto create_triggers_failed;
 203
 204        power_supply_changed(psy);
 205
 206        goto success;
 207
 208create_triggers_failed:
 209        device_del(dev);
 210kobject_set_name_failed:
 211device_add_failed:
 212        put_device(dev);
 213success:
 214        return rc;
 215}
 216EXPORT_SYMBOL_GPL(power_supply_register);
 217
 218void power_supply_unregister(struct power_supply *psy)
 219{
 220        cancel_work_sync(&psy->changed_work);
 221        sysfs_remove_link(&psy->dev->kobj, "powers");
 222        power_supply_remove_triggers(psy);
 223        device_unregister(psy->dev);
 224}
 225EXPORT_SYMBOL_GPL(power_supply_unregister);
 226
 227static int __init power_supply_class_init(void)
 228{
 229        power_supply_class = class_create(THIS_MODULE, "power_supply");
 230
 231        if (IS_ERR(power_supply_class))
 232                return PTR_ERR(power_supply_class);
 233
 234        power_supply_class->dev_uevent = power_supply_uevent;
 235        power_supply_init_attrs(&power_supply_dev_type);
 236
 237        return 0;
 238}
 239
 240static void __exit power_supply_class_exit(void)
 241{
 242        class_destroy(power_supply_class);
 243}
 244
 245subsys_initcall(power_supply_class_init);
 246module_exit(power_supply_class_exit);
 247
 248MODULE_DESCRIPTION("Universal power supply monitor class");
 249MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 250              "Szabolcs Gyurko, "
 251              "Anton Vorontsov <cbou@mail.ru>");
 252MODULE_LICENSE("GPL");
 253
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