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         unsigned int *count = data;
 102
 103         (*count)++;
 104         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 105                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 106                         return 0;
 107                 if (ret.intval)
 108                         return ret.intval;
 109         }
 110         return 0;
 111 }
 112
 113 int power_supply_is_system_supplied(void)
 114 {
 115         int error;
 116         unsigned int count = 0;
 117
 118         error = class_for_each_device(power_supply_class, NULL, &count,
 119                                       __power_supply_is_system_supplied);
 120
 121         /*
 122          * If no power class device was found at all, most probably we are
 123          * running on a desktop system, so assume we are on mains power.
 124          */
 125         if (count == 0)
 126                 return 1;
 127
 128         return error;
 129 }
 130 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 131
 132 int power_supply_set_battery_charged(struct power_supply *psy)
 133 {
 134         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 135                 psy->set_charged(psy);
 136                 return 0;
 137         }
 138
 139         return -EINVAL;
 140 }
 141 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 142
 143 static int power_supply_match_device_by_name(struct device *dev, void *data)
 144 {
 145         const char *name = data;
 146         struct power_supply *psy = dev_get_drvdata(dev);
 147
 148         return strcmp(psy->name, name) == 0;
 149 }
 150
 151 struct power_supply *power_supply_get_by_name(char *name)
 152 {
 153         struct device *dev = class_find_device(power_supply_class, NULL, name,
 154                                         power_supply_match_device_by_name);
 155
 156         return dev ? dev_get_drvdata(dev) : NULL;
 157 }
 158 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 159
 160 int power_supply_powers(struct power_supply *psy, struct device *dev)
 161 {
 162         return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 163 }
 164 EXPORT_SYMBOL_GPL(power_supply_powers);
 165
 166 static void power_supply_dev_release(struct device *dev)
 167 {
 168         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 169         kfree(dev);
 170 }
 171
 172 int power_supply_register(struct device *parent, struct power_supply *psy)
 173 {
 174         struct device *dev;
 175         int rc;
 176
 177         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 178         if (!dev)
 179                 return -ENOMEM;
 180
 181         device_initialize(dev);
 182
 183         dev->class = power_supply_class;
 184         dev->type = &power_supply_dev_type;
 185         dev->parent = parent;
 186         dev->release = power_supply_dev_release;
 187         dev_set_drvdata(dev, psy);
 188         psy->dev = dev;
 189
 190         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 191
 192         rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 193         if (rc)
 194                 goto kobject_set_name_failed;
 195
 196         rc = device_add(dev);
 197         if (rc)
 198                 goto device_add_failed;
 199
 200         rc = power_supply_create_triggers(psy);
 201         if (rc)
 202                 goto create_triggers_failed;
 203
 204         power_supply_changed(psy);
 205
 206         goto success;
 207
 208 create_triggers_failed:
 209         device_del(dev);
 210 kobject_set_name_failed:
 211 device_add_failed:
 212         put_device(dev);
 213 success:
 214         return rc;
 215 }
 216 EXPORT_SYMBOL_GPL(power_supply_register);
 217
 218 void power_supply_unregister(struct power_supply *psy)
 219 {
 220         cancel_work_sync(&psy->changed_work);
 221         sysfs_remove_link(&psy->dev->kobj, "powers");
 222         power_supply_remove_triggers(psy);
 223         device_unregister(psy->dev);
 224 }
 225 EXPORT_SYMBOL_GPL(power_supply_unregister);
 226
 227 static int __init power_supply_class_init(void)
 228 {
 229         power_supply_class = class_create(THIS_MODULE, "power_supply");
 230
 231         if (IS_ERR(power_supply_class))
 232                 return PTR_ERR(power_supply_class);
 233
 234         power_supply_class->dev_uevent = power_supply_uevent;
 235         power_supply_init_attrs(&power_supply_dev_type);
 236
 237         return 0;
 238 }
 239
 240 static void __exit power_supply_class_exit(void)
 241 {
 242         class_destroy(power_supply_class);
 243 }
 244
 245 subsys_initcall(power_supply_class_init);
 246 module_exit(power_supply_class_exit);
 247
 248 MODULE_DESCRIPTION("Universal power supply monitor class");
 249 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 250               "Szabolcs Gyurko, "
 251               "Anton Vorontsov <cbou@mail.ru>");
 252 MODULE_LICENSE("GPL");