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/device.h>
  17 #include <linux/err.h>
  18 #include <linux/power_supply.h>
  19 #include "power_supply.h"
  20
  21 /* exported for the APM Power driver, APM emulation */
  22 struct class *power_supply_class;
  23 EXPORT_SYMBOL_GPL(power_supply_class);
  24
  25 static int __power_supply_changed_work(struct device *dev, void *data)
  26 {
  27         struct power_supply *psy = (struct power_supply *)data;
  28         struct power_supply *pst = dev_get_drvdata(dev);
  29         int i;
  30
  31         for (i = 0; i < psy->num_supplicants; i++)
  32                 if (!strcmp(psy->supplied_to[i], pst->name)) {
  33                         if (pst->external_power_changed)
  34                                 pst->external_power_changed(pst);
  35                 }
  36         return 0;
  37 }
  38
  39 static void power_supply_changed_work(struct work_struct *work)
  40 {
  41         unsigned long flags;
  42         struct power_supply *psy = container_of(work, struct power_supply,
  43                                                 changed_work);
  44
  45         dev_dbg(psy->dev, "%s\n", __func__);
  46
  47         spin_lock_irqsave(&psy->changed_lock, flags);
  48         if (psy->changed) {
  49                 psy->changed = false;
  50                 spin_unlock_irqrestore(&psy->changed_lock, flags);
  51
  52                 class_for_each_device(power_supply_class, NULL, psy,
  53                                       __power_supply_changed_work);
  54
  55                 power_supply_update_leds(psy);
  56
  57                 kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  58                 spin_lock_irqsave(&psy->changed_lock, flags);
  59         }
  60         if (!psy->changed)
  61                 wake_unlock(&psy->work_wake_lock);
  62         spin_unlock_irqrestore(&psy->changed_lock, flags);
  63 }
  64
  65 void power_supply_changed(struct power_supply *psy)
  66 {
  67         unsigned long flags;
  68
  69         dev_dbg(psy->dev, "%s\n", __func__);
  70
  71         spin_lock_irqsave(&psy->changed_lock, flags);
  72         psy->changed = true;
  73         wake_lock(&psy->work_wake_lock);
  74         spin_unlock_irqrestore(&psy->changed_lock, flags);
  75         schedule_work(&psy->changed_work);
  76 }
  77 EXPORT_SYMBOL_GPL(power_supply_changed);
  78
  79 static int __power_supply_am_i_supplied(struct device *dev, void *data)
  80 {
  81         union power_supply_propval ret = {0,};
  82         struct power_supply *psy = (struct power_supply *)data;
  83         struct power_supply *epsy = dev_get_drvdata(dev);
  84         int i;
  85
  86         for (i = 0; i < epsy->num_supplicants; i++) {
  87                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
  88                         if (epsy->get_property(epsy,
  89                                   POWER_SUPPLY_PROP_ONLINE, &ret))
  90                                 continue;
  91                         if (ret.intval)
  92                                 return ret.intval;
  93                 }
  94         }
  95         return 0;
  96 }
  97
  98 int power_supply_am_i_supplied(struct power_supply *psy)
  99 {
 100         int error;
 101
 102         error = class_for_each_device(power_supply_class, NULL, psy,
 103                                       __power_supply_am_i_supplied);
 104
 105         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 106
 107         return error;
 108 }
 109 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 110
 111 static int __power_supply_is_system_supplied(struct device *dev, void *data)
 112 {
 113         union power_supply_propval ret = {0,};
 114         struct power_supply *psy = dev_get_drvdata(dev);
 115
 116         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 117                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 118                         return 0;
 119                 if (ret.intval)
 120                         return ret.intval;
 121         }
 122         return 0;
 123 }
 124
 125 int power_supply_is_system_supplied(void)
 126 {
 127         int error;
 128
 129         error = class_for_each_device(power_supply_class, NULL, NULL,
 130                                       __power_supply_is_system_supplied);
 131
 132         return error;
 133 }
 134 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 135
 136 int power_supply_set_battery_charged(struct power_supply *psy)
 137 {
 138         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 139                 psy->set_charged(psy);
 140                 return 0;
 141         }
 142
 143         return -EINVAL;
 144 }
 145 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 146
 147 static int power_supply_match_device_by_name(struct device *dev, void *data)
 148 {
 149         const char *name = data;
 150         struct power_supply *psy = dev_get_drvdata(dev);
 151
 152         return strcmp(psy->name, name) == 0;
 153 }
 154
 155 struct power_supply *power_supply_get_by_name(char *name)
 156 {
 157         struct device *dev = class_find_device(power_supply_class, NULL, name,
 158                                         power_supply_match_device_by_name);
 159
 160         return dev ? dev_get_drvdata(dev) : NULL;
 161 }
 162 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 163
 164 int power_supply_register(struct device *parent, struct power_supply *psy)
 165 {
 166         int rc = 0;
 167
 168         psy->dev = device_create(power_supply_class, parent, 0, psy,
 169                                  "%s", psy->name);
 170         if (IS_ERR(psy->dev)) {
 171                 rc = PTR_ERR(psy->dev);
 172                 goto dev_create_failed;
 173         }
 174
 175         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 176         spin_lock_init(&psy->changed_lock);
 177         wake_lock_init(&psy->work_wake_lock, WAKE_LOCK_SUSPEND, "power-supply");
 178
 179         rc = power_supply_create_attrs(psy);
 180         if (rc)
 181                 goto create_attrs_failed;
 182
 183         rc = power_supply_create_triggers(psy);
 184         if (rc)
 185                 goto create_triggers_failed;
 186
 187         power_supply_changed(psy);
 188
 189         goto success;
 190
 191 create_triggers_failed:
 192         power_supply_remove_attrs(psy);
 193 create_attrs_failed:
 194         wake_lock_destroy(&psy->work_wake_lock);
 195         device_unregister(psy->dev);
 196 dev_create_failed:
 197 success:
 198         return rc;
 199 }
 200 EXPORT_SYMBOL_GPL(power_supply_register);
 201
 202 void power_supply_unregister(struct power_supply *psy)
 203 {
 204         flush_scheduled_work();
 205         power_supply_remove_triggers(psy);
 206         power_supply_remove_attrs(psy);
 207         wake_lock_destroy(&psy->work_wake_lock);
 208         device_unregister(psy->dev);
 209 }
 210 EXPORT_SYMBOL_GPL(power_supply_unregister);
 211
 212 static int __init power_supply_class_init(void)
 213 {
 214         power_supply_class = class_create(THIS_MODULE, "power_supply");
 215
 216         if (IS_ERR(power_supply_class))
 217                 return PTR_ERR(power_supply_class);
 218
 219         power_supply_class->dev_uevent = power_supply_uevent;
 220
 221         return 0;
 222 }
 223
 224 static void __exit power_supply_class_exit(void)
 225 {
 226         class_destroy(power_supply_class);
 227 }
 228
 229 subsys_initcall(power_supply_class_init);
 230 module_exit(power_supply_class_exit);
 231
 232 MODULE_DESCRIPTION("Universal power supply monitor class");
 233 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 234               "Szabolcs Gyurko, "
 235               "Anton Vorontsov <cbou@mail.ru>");
 236 MODULE_LICENSE("GPL");