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         struct power_supply *psy = container_of(work, struct power_supply,
  45                                                 changed_work);
  46
  47         dev_dbg(psy->dev, "%s\n", __func__);
  48
  49         class_for_each_device(power_supply_class, NULL, psy,
  50                               __power_supply_changed_work);
  51
  52         power_supply_update_leds(psy);
  53
  54         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  55 }
  56
  57 void power_supply_changed(struct power_supply *psy)
  58 {
  59         dev_dbg(psy->dev, "%s\n", __func__);
  60
  61         schedule_work(&psy->changed_work);
  62 }
  63 EXPORT_SYMBOL_GPL(power_supply_changed);
  64
  65 static int __power_supply_am_i_supplied(struct device *dev, void *data)
  66 {
  67         union power_supply_propval ret = {0,};
  68         struct power_supply *psy = (struct power_supply *)data;
  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                                 return ret.intval;
  79                 }
  80         }
  81         return 0;
  82 }
  83
  84 int power_supply_am_i_supplied(struct power_supply *psy)
  85 {
  86         int error;
  87
  88         error = class_for_each_device(power_supply_class, NULL, psy,
  89                                       __power_supply_am_i_supplied);
  90
  91         dev_dbg(psy->dev, "%s %d\n", __func__, error);
  92
  93         return error;
  94 }
  95 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
  96
  97 static int __power_supply_is_system_supplied(struct device *dev, void *data)
  98 {
  99         union power_supply_propval ret = {0,};
 100         struct power_supply *psy = dev_get_drvdata(dev);
 101
 102         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 103                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 104                         return 0;
 105                 if (ret.intval)
 106                         return ret.intval;
 107         }
 108         return 0;
 109 }
 110
 111 int power_supply_is_system_supplied(void)
 112 {
 113         int error;
 114
 115         error = class_for_each_device(power_supply_class, NULL, NULL,
 116                                       __power_supply_is_system_supplied);
 117
 118         return error;
 119 }
 120 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 121
 122 int power_supply_set_battery_charged(struct power_supply *psy)
 123 {
 124         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 125                 psy->set_charged(psy);
 126                 return 0;
 127         }
 128
 129         return -EINVAL;
 130 }
 131 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 132
 133 static int power_supply_match_device_by_name(struct device *dev, void *data)
 134 {
 135         const char *name = data;
 136         struct power_supply *psy = dev_get_drvdata(dev);
 137
 138         return strcmp(psy->name, name) == 0;
 139 }
 140
 141 struct power_supply *power_supply_get_by_name(char *name)
 142 {
 143         struct device *dev = class_find_device(power_supply_class, NULL, name,
 144                                         power_supply_match_device_by_name);
 145
 146         return dev ? dev_get_drvdata(dev) : NULL;
 147 }
 148 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 149
 150 int power_supply_powers(struct power_supply *psy, struct device *dev)
 151 {
 152         return sysfs_create_link_nowarn(&psy->dev->kobj, &dev->kobj, "powers");
 153 }
 154 EXPORT_SYMBOL_GPL(power_supply_powers);
 155
 156 static void power_supply_dev_release(struct device *dev)
 157 {
 158         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 159         kfree(dev);
 160 }
 161
 162 int power_supply_register(struct device *parent, struct power_supply *psy)
 163 {
 164         struct device *dev;
 165         int rc;
 166
 167         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 168         if (!dev)
 169                 return -ENOMEM;
 170
 171         device_initialize(dev);
 172
 173         dev->class = power_supply_class;
 174         dev->type = &power_supply_dev_type;
 175         dev->parent = parent;
 176         dev->release = power_supply_dev_release;
 177         dev_set_drvdata(dev, psy);
 178         psy->dev = dev;
 179
 180         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 181
 182         rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 183         if (rc)
 184                 goto kobject_set_name_failed;
 185
 186         rc = device_add(dev);
 187         if (rc)
 188                 goto device_add_failed;
 189
 190         rc = power_supply_create_triggers(psy);
 191         if (rc)
 192                 goto create_triggers_failed;
 193
 194         power_supply_changed(psy);
 195
 196         goto success;
 197
 198 create_triggers_failed:
 199         device_del(dev);
 200 kobject_set_name_failed:
 201 device_add_failed:
 202         put_device(dev);
 203 success:
 204         return rc;
 205 }
 206 EXPORT_SYMBOL_GPL(power_supply_register);
 207
 208 void power_supply_unregister(struct power_supply *psy)
 209 {
 210         cancel_work_sync(&psy->changed_work);
 211         sysfs_remove_link(&psy->dev->kobj, "powers");
 212         power_supply_remove_triggers(psy);
 213         device_unregister(psy->dev);
 214 }
 215 EXPORT_SYMBOL_GPL(power_supply_unregister);
 216
 217 static int __init power_supply_class_init(void)
 218 {
 219         power_supply_class = class_create(THIS_MODULE, "power_supply");
 220
 221         if (IS_ERR(power_supply_class))
 222                 return PTR_ERR(power_supply_class);
 223
 224         power_supply_class->dev_uevent = power_supply_uevent;
 225         power_supply_init_attrs(&power_supply_dev_type);
 226
 227         return 0;
 228 }
 229
 230 static void __exit power_supply_class_exit(void)
 231 {
 232         class_destroy(power_supply_class);
 233 }
 234
 235 subsys_initcall(power_supply_class_init);
 236 module_exit(power_supply_class_exit);
 237
 238 MODULE_DESCRIPTION("Universal power supply monitor class");
 239 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 240               "Szabolcs Gyurko, "
 241               "Anton Vorontsov <cbou@mail.ru>");
 242 MODULE_LICENSE("GPL");