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/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 */
  23 struct class *power_supply_class;
  24 EXPORT_SYMBOL_GPL(power_supply_class);
  25
  26 static struct device_type power_supply_dev_type;
  27
  28 static 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
  42 static void power_supply_changed_work(struct work_struct *work)
  43 {
  44         unsigned long flags;
  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         spin_lock_irqsave(&psy->changed_lock, flags);
  51         if (psy->changed) {
  52                 psy->changed = false;
  53                 spin_unlock_irqrestore(&psy->changed_lock, flags);
  54
  55                 class_for_each_device(power_supply_class, NULL, psy,
  56                                       __power_supply_changed_work);
  57
  58                 power_supply_update_leds(psy);
  59
  60                 kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  61                 spin_lock_irqsave(&psy->changed_lock, flags);
  62         }
  63         if (!psy->changed)
  64                 wake_unlock(&psy->work_wake_lock);
  65         spin_unlock_irqrestore(&psy->changed_lock, flags);
  66 }
  67
  68 void power_supply_changed(struct power_supply *psy)
  69 {
  70         unsigned long flags;
  71
  72         dev_dbg(psy->dev, "%s\n", __func__);
  73
  74         spin_lock_irqsave(&psy->changed_lock, flags);
  75         psy->changed = true;
  76         wake_lock(&psy->work_wake_lock);
  77         spin_unlock_irqrestore(&psy->changed_lock, flags);
  78         schedule_work(&psy->changed_work);
  79 }
  80 EXPORT_SYMBOL_GPL(power_supply_changed);
  81
  82 static int __power_supply_am_i_supplied(struct device *dev, void *data)
  83 {
  84         union power_supply_propval ret = {0,};
  85         struct power_supply *psy = (struct power_supply *)data;
  86         struct power_supply *epsy = dev_get_drvdata(dev);
  87         int i;
  88
  89         for (i = 0; i < epsy->num_supplicants; i++) {
  90                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
  91                         if (epsy->get_property(epsy,
  92                                   POWER_SUPPLY_PROP_ONLINE, &ret))
  93                                 continue;
  94                         if (ret.intval)
  95                                 return ret.intval;
  96                 }
  97         }
  98         return 0;
  99 }
 100
 101 int power_supply_am_i_supplied(struct power_supply *psy)
 102 {
 103         int error;
 104
 105         error = class_for_each_device(power_supply_class, NULL, psy,
 106                                       __power_supply_am_i_supplied);
 107
 108         dev_dbg(psy->dev, "%s %d\n", __func__, error);
 109
 110         return error;
 111 }
 112 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 113
 114 static int __power_supply_is_system_supplied(struct device *dev, void *data)
 115 {
 116         union power_supply_propval ret = {0,};
 117         struct power_supply *psy = dev_get_drvdata(dev);
 118
 119         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 120                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 121                         return 0;
 122                 if (ret.intval)
 123                         return ret.intval;
 124         }
 125         return 0;
 126 }
 127
 128 int power_supply_is_system_supplied(void)
 129 {
 130         int error;
 131
 132         error = class_for_each_device(power_supply_class, NULL, NULL,
 133                                       __power_supply_is_system_supplied);
 134
 135         return error;
 136 }
 137 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 138
 139 int power_supply_set_battery_charged(struct power_supply *psy)
 140 {
 141         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 142                 psy->set_charged(psy);
 143                 return 0;
 144         }
 145
 146         return -EINVAL;
 147 }
 148 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 149
 150 static int power_supply_match_device_by_name(struct device *dev, void *data)
 151 {
 152         const char *name = data;
 153         struct power_supply *psy = dev_get_drvdata(dev);
 154
 155         return strcmp(psy->name, name) == 0;
 156 }
 157
 158 struct power_supply *power_supply_get_by_name(char *name)
 159 {
 160         struct device *dev = class_find_device(power_supply_class, NULL, name,
 161                                         power_supply_match_device_by_name);
 162
 163         return dev ? dev_get_drvdata(dev) : NULL;
 164 }
 165 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 166
 167 static 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 int power_supply_register(struct device *parent, struct power_supply *psy)
 174 {
 175         struct device *dev;
 176         int rc;
 177
 178         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 179         if (!dev)
 180                 return -ENOMEM;
 181
 182         device_initialize(dev);
 183
 184         dev->class = power_supply_class;
 185         dev->type = &power_supply_dev_type;
 186         dev->parent = parent;
 187         dev->release = power_supply_dev_release;
 188         dev_set_drvdata(dev, psy);
 189         psy->dev = dev;
 190
 191         rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 192         if (rc)
 193                 goto kobject_set_name_failed;
 194
 195         rc = device_add(dev);
 196         if (rc)
 197                 goto device_add_failed;
 198
 199         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 200         spin_lock_init(&psy->changed_lock);
 201         wake_lock_init(&psy->work_wake_lock, WAKE_LOCK_SUSPEND, "power-supply");
 202
 203         rc = power_supply_create_triggers(psy);
 204         if (rc)
 205                 goto create_triggers_failed;
 206
 207         power_supply_changed(psy);
 208
 209         goto success;
 210
 211 create_triggers_failed:
 212         wake_lock_destroy(&psy->work_wake_lock);
 213         device_unregister(psy->dev);
 214 kobject_set_name_failed:
 215 device_add_failed:
 216         kfree(dev);
 217 success:
 218         return rc;
 219 }
 220 EXPORT_SYMBOL_GPL(power_supply_register);
 221
 222 void power_supply_unregister(struct power_supply *psy)
 223 {
 224         flush_scheduled_work();
 225         power_supply_remove_triggers(psy);
 226         wake_lock_destroy(&psy->work_wake_lock);
 227         device_unregister(psy->dev);
 228 }
 229 EXPORT_SYMBOL_GPL(power_supply_unregister);
 230
 231 static int __init power_supply_class_init(void)
 232 {
 233         power_supply_class = class_create(THIS_MODULE, "power_supply");
 234
 235         if (IS_ERR(power_supply_class))
 236                 return PTR_ERR(power_supply_class);
 237
 238         power_supply_class->dev_uevent = power_supply_uevent;
 239         power_supply_init_attrs(&power_supply_dev_type);
 240
 241         return 0;
 242 }
 243
 244 static void __exit power_supply_class_exit(void)
 245 {
 246         class_destroy(power_supply_class);
 247 }
 248
 249 subsys_initcall(power_supply_class_init);
 250 module_exit(power_supply_class_exit);
 251
 252 MODULE_DESCRIPTION("Universal power supply monitor class");
 253 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 254               "Szabolcs Gyurko, "
 255               "Anton Vorontsov <cbou@mail.ru>");
 256 MODULE_LICENSE("GPL");