linux/drivers/power/power_supply_core.c
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   1/*
   2 *  Universal power supply monitor class
   3 *
   4 *  Copyright \xC2\xA9 2007  Anton Vorontsov <cbou@mail.ru>
   5 *  Copyright \xC2\xA9 2004  Szabolcs Gyurko
   6 *  Copyright \xC2\xA9 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
 102        if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 103                if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 104                        return 0;
 105                if (ret.intval)
 106                        return ret.intval;
 107        }
 108        return 0;
 109}
 110
 111int power_supply_is_system_supplied(void)
 112{
 113        int error;
 114
 115        error = class_for_each_device(power_supply_class, NULL, NULL,
 116                                      __power_supply_is_system_supplied);
 117
 118        return error;
 119}
 120EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 121
 122int power_supply_set_battery_charged(struct power_supply *psy)
 123{
 124        if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 125                psy->set_charged(psy);
 126                return 0;
 127        }
 128
 129        return -EINVAL;
 130}
 131EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 132
 133static int power_supply_match_device_by_name(struct device *dev, void *data)
 134{
 135        const char *name = data;
 136        struct power_supply *psy = dev_get_drvdata(dev);
 137
 138        return strcmp(psy->name, name) == 0;
 139}
 140
 141struct power_supply *power_supply_get_by_name(char *name)
 142{
 143        struct device *dev = class_find_device(power_supply_class, NULL, name,
 144                                        power_supply_match_device_by_name);
 145
 146        return dev ? dev_get_drvdata(dev) : NULL;
 147}
 148EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 149
 150static void power_supply_dev_release(struct device *dev)
 151{
 152        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 153        kfree(dev);
 154}
 155
 156int power_supply_register(struct device *parent, struct power_supply *psy)
 157{
 158        struct device *dev;
 159        int rc;
 160
 161        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 162        if (!dev)
 163                return -ENOMEM;
 164
 165        device_initialize(dev);
 166
 167        dev->class = power_supply_class;
 168        dev->type = &power_supply_dev_type;
 169        dev->parent = parent;
 170        dev->release = power_supply_dev_release;
 171        dev_set_drvdata(dev, psy);
 172        psy->dev = dev;
 173
 174        rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 175        if (rc)
 176                goto kobject_set_name_failed;
 177
 178        rc = device_add(dev);
 179        if (rc)
 180                goto device_add_failed;
 181
 182        INIT_WORK(&psy->changed_work, power_supply_changed_work);
 183
 184        rc = power_supply_create_triggers(psy);
 185        if (rc)
 186                goto create_triggers_failed;
 187
 188        power_supply_changed(psy);
 189
 190        goto success;
 191
 192create_triggers_failed:
 193        device_unregister(psy->dev);
 194kobject_set_name_failed:
 195device_add_failed:
 196        kfree(dev);
 197success:
 198        return rc;
 199}
 200EXPORT_SYMBOL_GPL(power_supply_register);
 201
 202void power_supply_unregister(struct power_supply *psy)
 203{
 204        flush_scheduled_work();
 205        power_supply_remove_triggers(psy);
 206        device_unregister(psy->dev);
 207}
 208EXPORT_SYMBOL_GPL(power_supply_unregister);
 209
 210static int __init power_supply_class_init(void)
 211{
 212        power_supply_class = class_create(THIS_MODULE, "power_supply");
 213
 214        if (IS_ERR(power_supply_class))
 215                return PTR_ERR(power_supply_class);
 216
 217        power_supply_class->dev_uevent = power_supply_uevent;
 218        power_supply_init_attrs(&power_supply_dev_type);
 219
 220        return 0;
 221}
 222
 223static void __exit power_supply_class_exit(void)
 224{
 225        class_destroy(power_supply_class);
 226}
 227
 228subsys_initcall(power_supply_class_init);
 229module_exit(power_supply_class_exit);
 230
 231MODULE_DESCRIPTION("Universal power supply monitor class");
 232MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 233              "Szabolcs Gyurko, "
 234              "Anton Vorontsov <cbou@mail.ru>");
 235MODULE_LICENSE("GPL");
 236