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         struct power_supply *psy = container_of(work, struct power_supply,
  42                                                 changed_work);
  43
  44         dev_dbg(psy->dev, "%s\n", __func__);
  45
  46         class_for_each_device(power_supply_class, NULL, psy,
  47                               __power_supply_changed_work);
  48
  49         power_supply_update_leds(psy);
  50
  51         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  52 }
  53
  54 void power_supply_changed(struct power_supply *psy)
  55 {
  56         dev_dbg(psy->dev, "%s\n", __func__);
  57
  58         schedule_work(&psy->changed_work);
  59 }
  60 EXPORT_SYMBOL_GPL(power_supply_changed);
  61
  62 static int __power_supply_am_i_supplied(struct device *dev, void *data)
  63 {
  64         union power_supply_propval ret = {0,};
  65         struct power_supply *psy = (struct power_supply *)data;
  66         struct power_supply *epsy = dev_get_drvdata(dev);
  67         int i;
  68
  69         for (i = 0; i < epsy->num_supplicants; i++) {
  70                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
  71                         if (epsy->get_property(epsy,
  72                                   POWER_SUPPLY_PROP_ONLINE, &ret))
  73                                 continue;
  74                         if (ret.intval)
  75                                 return ret.intval;
  76                 }
  77         }
  78         return 0;
  79 }
  80
  81 int power_supply_am_i_supplied(struct power_supply *psy)
  82 {
  83         int error;
  84
  85         error = class_for_each_device(power_supply_class, NULL, psy,
  86                                       __power_supply_am_i_supplied);
  87
  88         dev_dbg(psy->dev, "%s %d\n", __func__, error);
  89
  90         return error;
  91 }
  92 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
  93
  94 static int __power_supply_is_system_supplied(struct device *dev, void *data)
  95 {
  96         union power_supply_propval ret = {0,};
  97         struct power_supply *psy = dev_get_drvdata(dev);
  98
  99         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 100                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 101                         return 0;
 102                 if (ret.intval)
 103                         return ret.intval;
 104         }
 105         return 0;
 106 }
 107
 108 int power_supply_is_system_supplied(void)
 109 {
 110         int error;
 111
 112         error = class_for_each_device(power_supply_class, NULL, NULL,
 113                                       __power_supply_is_system_supplied);
 114
 115         return error;
 116 }
 117 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 118
 119 int power_supply_register(struct device *parent, struct power_supply *psy)
 120 {
 121         int rc = 0;
 122
 123         psy->dev = device_create(power_supply_class, parent, 0, psy,
 124                                  "%s", psy->name);
 125         if (IS_ERR(psy->dev)) {
 126                 rc = PTR_ERR(psy->dev);
 127                 goto dev_create_failed;
 128         }
 129
 130         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 131
 132         rc = power_supply_create_attrs(psy);
 133         if (rc)
 134                 goto create_attrs_failed;
 135
 136         rc = power_supply_create_triggers(psy);
 137         if (rc)
 138                 goto create_triggers_failed;
 139
 140         power_supply_changed(psy);
 141
 142         goto success;
 143
 144 create_triggers_failed:
 145         power_supply_remove_attrs(psy);
 146 create_attrs_failed:
 147         device_unregister(psy->dev);
 148 dev_create_failed:
 149 success:
 150         return rc;
 151 }
 152 EXPORT_SYMBOL_GPL(power_supply_register);
 153
 154 void power_supply_unregister(struct power_supply *psy)
 155 {
 156         flush_scheduled_work();
 157         power_supply_remove_triggers(psy);
 158         power_supply_remove_attrs(psy);
 159         device_unregister(psy->dev);
 160 }
 161 EXPORT_SYMBOL_GPL(power_supply_unregister);
 162
 163 static int __init power_supply_class_init(void)
 164 {
 165         power_supply_class = class_create(THIS_MODULE, "power_supply");
 166
 167         if (IS_ERR(power_supply_class))
 168                 return PTR_ERR(power_supply_class);
 169
 170         power_supply_class->dev_uevent = power_supply_uevent;
 171
 172         return 0;
 173 }
 174
 175 static void __exit power_supply_class_exit(void)
 176 {
 177         class_destroy(power_supply_class);
 178 }
 179
 180 subsys_initcall(power_supply_class_init);
 181 module_exit(power_supply_class_exit);
 182
 183 MODULE_DESCRIPTION("Universal power supply monitor class");
 184 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 185               "Szabolcs Gyurko, "
 186               "Anton Vorontsov <cbou@mail.ru>");
 187 MODULE_LICENSE("GPL");