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 struct class *power_supply_class;
  22
  23 static void power_supply_changed_work(struct work_struct *work)
  24 {
  25         struct power_supply *psy = container_of(work, struct power_supply,
  26                                                 changed_work);
  27         int i;
  28
  29         dev_dbg(psy->dev, "%s\n", __FUNCTION__);
  30
  31         for (i = 0; i < psy->num_supplicants; i++) {
  32                 struct device *dev;
  33
  34                 down(&power_supply_class->sem);
  35                 list_for_each_entry(dev, &power_supply_class->devices, node) {
  36                         struct power_supply *pst = dev_get_drvdata(dev);
  37
  38                         if (!strcmp(psy->supplied_to[i], pst->name)) {
  39                                 if (pst->external_power_changed)
  40                                         pst->external_power_changed(pst);
  41                         }
  42                 }
  43                 up(&power_supply_class->sem);
  44         }
  45
  46         power_supply_update_leds(psy);
  47
  48         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  49
  50         return;
  51 }
  52
  53 void power_supply_changed(struct power_supply *psy)
  54 {
  55         dev_dbg(psy->dev, "%s\n", __FUNCTION__);
  56
  57         schedule_work(&psy->changed_work);
  58
  59         return;
  60 }
  61
  62 int power_supply_am_i_supplied(struct power_supply *psy)
  63 {
  64         union power_supply_propval ret = {0,};
  65         struct device *dev;
  66
  67         down(&power_supply_class->sem);
  68         list_for_each_entry(dev, &power_supply_class->devices, node) {
  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                                         goto out;
  79                         }
  80                 }
  81         }
  82 out:
  83         up(&power_supply_class->sem);
  84
  85         dev_dbg(psy->dev, "%s %d\n", __FUNCTION__, ret.intval);
  86
  87         return ret.intval;
  88 }
  89
  90 int power_supply_register(struct device *parent, struct power_supply *psy)
  91 {
  92         int rc = 0;
  93
  94         psy->dev = device_create(power_supply_class, parent, 0,
  95                                  "%s", psy->name);
  96         if (IS_ERR(psy->dev)) {
  97                 rc = PTR_ERR(psy->dev);
  98                 goto dev_create_failed;
  99         }
 100
 101         dev_set_drvdata(psy->dev, psy);
 102
 103         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 104
 105         rc = power_supply_create_attrs(psy);
 106         if (rc)
 107                 goto create_attrs_failed;
 108
 109         rc = power_supply_create_triggers(psy);
 110         if (rc)
 111                 goto create_triggers_failed;
 112
 113         power_supply_changed(psy);
 114
 115         goto success;
 116
 117 create_triggers_failed:
 118         power_supply_remove_attrs(psy);
 119 create_attrs_failed:
 120         device_unregister(psy->dev);
 121 dev_create_failed:
 122 success:
 123         return rc;
 124 }
 125
 126 void power_supply_unregister(struct power_supply *psy)
 127 {
 128         flush_scheduled_work();
 129         power_supply_remove_triggers(psy);
 130         power_supply_remove_attrs(psy);
 131         device_unregister(psy->dev);
 132         return;
 133 }
 134
 135 static int __init power_supply_class_init(void)
 136 {
 137         power_supply_class = class_create(THIS_MODULE, "power_supply");
 138
 139         if (IS_ERR(power_supply_class))
 140                 return PTR_ERR(power_supply_class);
 141
 142         power_supply_class->dev_uevent = power_supply_uevent;
 143
 144         return 0;
 145 }
 146
 147 static void __exit power_supply_class_exit(void)
 148 {
 149         class_destroy(power_supply_class);
 150         return;
 151 }
 152
 153 EXPORT_SYMBOL_GPL(power_supply_changed);
 154 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 155 EXPORT_SYMBOL_GPL(power_supply_register);
 156 EXPORT_SYMBOL_GPL(power_supply_unregister);
 157
 158 /* exported for the APM Power driver, APM emulation */
 159 EXPORT_SYMBOL_GPL(power_supply_class);
 160
 161 subsys_initcall(power_supply_class_init);
 162 module_exit(power_supply_class_exit);
 163
 164 MODULE_DESCRIPTION("Universal power supply monitor class");
 165 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 166               "Szabolcs Gyurko, "
 167               "Anton Vorontsov <cbou@mail.ru>");
 168 MODULE_LICENSE("GPL");