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 int __power_supply_changed_work(struct device *dev, void *data)
  24 {
  25         struct power_supply *psy = (struct power_supply *)data;
  26         struct power_supply *pst = dev_get_drvdata(dev);
  27         int i;
  28
  29         for (i = 0; i < psy->num_supplicants; i++)
  30                 if (!strcmp(psy->supplied_to[i], pst->name)) {
  31                         if (pst->external_power_changed)
  32                                 pst->external_power_changed(pst);
  33                 }
  34         return 0;
  35 }
  36
  37 static void power_supply_changed_work(struct work_struct *work)
  38 {
  39         struct power_supply *psy = container_of(work, struct power_supply,
  40                                                 changed_work);
  41
  42         dev_dbg(psy->dev, "%s\n", __func__);
  43
  44         class_for_each_device(power_supply_class, NULL, psy,
  45                               __power_supply_changed_work);
  46
  47         power_supply_update_leds(psy);
  48
  49         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  50 }
  51
  52 void power_supply_changed(struct power_supply *psy)
  53 {
  54         dev_dbg(psy->dev, "%s\n", __func__);
  55
  56         schedule_work(&psy->changed_work);
  57 }
  58
  59 static int __power_supply_am_i_supplied(struct device *dev, void *data)
  60 {
  61         union power_supply_propval ret = {0,};
  62         struct power_supply *psy = (struct power_supply *)data;
  63         struct power_supply *epsy = dev_get_drvdata(dev);
  64         int i;
  65
  66         for (i = 0; i < epsy->num_supplicants; i++) {
  67                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
  68                         if (epsy->get_property(epsy,
  69                                   POWER_SUPPLY_PROP_ONLINE, &ret))
  70                                 continue;
  71                         if (ret.intval)
  72                                 return ret.intval;
  73                 }
  74         }
  75         return 0;
  76 }
  77
  78 int power_supply_am_i_supplied(struct power_supply *psy)
  79 {
  80         int error;
  81
  82         error = class_for_each_device(power_supply_class, NULL, psy,
  83                                       __power_supply_am_i_supplied);
  84
  85         dev_dbg(psy->dev, "%s %d\n", __func__, error);
  86
  87         return error;
  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, psy,
  95                                  "%s", psy->name);
  96         if (IS_ERR(psy->dev)) {
  97                 rc = PTR_ERR(psy->dev);
  98                 goto dev_create_failed;
  99         }
 100
 101         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 102
 103         rc = power_supply_create_attrs(psy);
 104         if (rc)
 105                 goto create_attrs_failed;
 106
 107         rc = power_supply_create_triggers(psy);
 108         if (rc)
 109                 goto create_triggers_failed;
 110
 111         power_supply_changed(psy);
 112
 113         goto success;
 114
 115 create_triggers_failed:
 116         power_supply_remove_attrs(psy);
 117 create_attrs_failed:
 118         device_unregister(psy->dev);
 119 dev_create_failed:
 120 success:
 121         return rc;
 122 }
 123
 124 void power_supply_unregister(struct power_supply *psy)
 125 {
 126         flush_scheduled_work();
 127         power_supply_remove_triggers(psy);
 128         power_supply_remove_attrs(psy);
 129         device_unregister(psy->dev);
 130 }
 131
 132 static int __init power_supply_class_init(void)
 133 {
 134         power_supply_class = class_create(THIS_MODULE, "power_supply");
 135
 136         if (IS_ERR(power_supply_class))
 137                 return PTR_ERR(power_supply_class);
 138
 139         power_supply_class->dev_uevent = power_supply_uevent;
 140
 141         return 0;
 142 }
 143
 144 static void __exit power_supply_class_exit(void)
 145 {
 146         class_destroy(power_supply_class);
 147 }
 148
 149 EXPORT_SYMBOL_GPL(power_supply_changed);
 150 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 151 EXPORT_SYMBOL_GPL(power_supply_register);
 152 EXPORT_SYMBOL_GPL(power_supply_unregister);
 153
 154 /* exported for the APM Power driver, APM emulation */
 155 EXPORT_SYMBOL_GPL(power_supply_class);
 156
 157 subsys_initcall(power_supply_class_init);
 158 module_exit(power_supply_class_exit);
 159
 160 MODULE_DESCRIPTION("Universal power supply monitor class");
 161 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 162               "Szabolcs Gyurko, "
 163               "Anton Vorontsov <cbou@mail.ru>");
 164 MODULE_LICENSE("GPL");