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 <linux/thermal.h>
  21 #include "power_supply.h"
  22
  23 /* exported for the APM Power driver, APM emulation */
  24 struct class *power_supply_class;
  25 EXPORT_SYMBOL_GPL(power_supply_class);
  26
  27 static struct device_type power_supply_dev_type;
  28
  29 static int __power_supply_changed_work(struct device *dev, void *data)
  30 {
  31         struct power_supply *psy = (struct power_supply *)data;
  32         struct power_supply *pst = dev_get_drvdata(dev);
  33         int i;
  34
  35         for (i = 0; i < psy->num_supplicants; i++)
  36                 if (!strcmp(psy->supplied_to[i], pst->name)) {
  37                         if (pst->external_power_changed)
  38                                 pst->external_power_changed(pst);
  39                 }
  40         return 0;
  41 }
  42
  43 static void power_supply_changed_work(struct work_struct *work)
  44 {
  45         struct power_supply *psy = container_of(work, struct power_supply,
  46                                                 changed_work);
  47
  48         dev_dbg(psy->dev, "%s\n", __func__);
  49
  50         class_for_each_device(power_supply_class, NULL, psy,
  51                               __power_supply_changed_work);
  52
  53         power_supply_update_leds(psy);
  54
  55         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
  56 }
  57
  58 void power_supply_changed(struct power_supply *psy)
  59 {
  60         dev_dbg(psy->dev, "%s\n", __func__);
  61
  62         schedule_work(&psy->changed_work);
  63 }
  64 EXPORT_SYMBOL_GPL(power_supply_changed);
  65
  66 static int __power_supply_am_i_supplied(struct device *dev, void *data)
  67 {
  68         union power_supply_propval ret = {0,};
  69         struct power_supply *psy = (struct power_supply *)data;
  70         struct power_supply *epsy = dev_get_drvdata(dev);
  71         int i;
  72
  73         for (i = 0; i < epsy->num_supplicants; i++) {
  74                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
  75                         if (epsy->get_property(epsy,
  76                                   POWER_SUPPLY_PROP_ONLINE, &ret))
  77                                 continue;
  78                         if (ret.intval)
  79                                 return ret.intval;
  80                 }
  81         }
  82         return 0;
  83 }
  84
  85 int power_supply_am_i_supplied(struct power_supply *psy)
  86 {
  87         int error;
  88
  89         error = class_for_each_device(power_supply_class, NULL, psy,
  90                                       __power_supply_am_i_supplied);
  91
  92         dev_dbg(psy->dev, "%s %d\n", __func__, error);
  93
  94         return error;
  95 }
  96 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
  97
  98 static int __power_supply_is_system_supplied(struct device *dev, void *data)
  99 {
 100         union power_supply_propval ret = {0,};
 101         struct power_supply *psy = dev_get_drvdata(dev);
 102         unsigned int *count = data;
 103
 104         (*count)++;
 105         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
 106                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
 107                         return 0;
 108                 if (ret.intval)
 109                         return ret.intval;
 110         }
 111         return 0;
 112 }
 113
 114 int power_supply_is_system_supplied(void)
 115 {
 116         int error;
 117         unsigned int count = 0;
 118
 119         error = class_for_each_device(power_supply_class, NULL, &count,
 120                                       __power_supply_is_system_supplied);
 121
 122         /*
 123          * If no power class device was found at all, most probably we are
 124          * running on a desktop system, so assume we are on mains power.
 125          */
 126         if (count == 0)
 127                 return 1;
 128
 129         return error;
 130 }
 131 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 132
 133 int power_supply_set_battery_charged(struct power_supply *psy)
 134 {
 135         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
 136                 psy->set_charged(psy);
 137                 return 0;
 138         }
 139
 140         return -EINVAL;
 141 }
 142 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 143
 144 static int power_supply_match_device_by_name(struct device *dev, void *data)
 145 {
 146         const char *name = data;
 147         struct power_supply *psy = dev_get_drvdata(dev);
 148
 149         return strcmp(psy->name, name) == 0;
 150 }
 151
 152 struct power_supply *power_supply_get_by_name(char *name)
 153 {
 154         struct device *dev = class_find_device(power_supply_class, NULL, name,
 155                                         power_supply_match_device_by_name);
 156
 157         return dev ? dev_get_drvdata(dev) : NULL;
 158 }
 159 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 160
 161 int power_supply_powers(struct power_supply *psy, struct device *dev)
 162 {
 163         return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
 164 }
 165 EXPORT_SYMBOL_GPL(power_supply_powers);
 166
 167 static void power_supply_dev_release(struct device *dev)
 168 {
 169         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 170         kfree(dev);
 171 }
 172
 173 #ifdef CONFIG_THERMAL
 174 static int power_supply_read_temp(struct thermal_zone_device *tzd,
 175                 unsigned long *temp)
 176 {
 177         struct power_supply *psy;
 178         union power_supply_propval val;
 179         int ret;
 180
 181         WARN_ON(tzd == NULL);
 182         psy = tzd->devdata;
 183         ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
 184
 185         /* Convert tenths of degree Celsius to milli degree Celsius. */
 186         if (!ret)
 187                 *temp = val.intval * 100;
 188
 189         return ret;
 190 }
 191
 192 static struct thermal_zone_device_ops psy_tzd_ops = {
 193         .get_temp = power_supply_read_temp,
 194 };
 195
 196 static int psy_register_thermal(struct power_supply *psy)
 197 {
 198         int i;
 199
 200         /* Register battery zone device psy reports temperature */
 201         for (i = 0; i < psy->num_properties; i++) {
 202                 if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
 203                         psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
 204                                         psy, &psy_tzd_ops, 0, 0, 0, 0);
 205                         if (IS_ERR(psy->tzd))
 206                                 return PTR_ERR(psy->tzd);
 207                         break;
 208                 }
 209         }
 210         return 0;
 211 }
 212
 213 static void psy_unregister_thermal(struct power_supply *psy)
 214 {
 215         if (IS_ERR_OR_NULL(psy->tzd))
 216                 return;
 217         thermal_zone_device_unregister(psy->tzd);
 218 }
 219 #else
 220 static int psy_register_thermal(struct power_supply *psy)
 221 {
 222         return 0;
 223 }
 224
 225 static void psy_unregister_thermal(struct power_supply *psy)
 226 {
 227 }
 228 #endif
 229
 230 int power_supply_register(struct device *parent, struct power_supply *psy)
 231 {
 232         struct device *dev;
 233         int rc;
 234
 235         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 236         if (!dev)
 237                 return -ENOMEM;
 238
 239         device_initialize(dev);
 240
 241         dev->class = power_supply_class;
 242         dev->type = &power_supply_dev_type;
 243         dev->parent = parent;
 244         dev->release = power_supply_dev_release;
 245         dev_set_drvdata(dev, psy);
 246         psy->dev = dev;
 247
 248         INIT_WORK(&psy->changed_work, power_supply_changed_work);
 249
 250         rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 251         if (rc)
 252                 goto kobject_set_name_failed;
 253
 254         rc = device_add(dev);
 255         if (rc)
 256                 goto device_add_failed;
 257
 258         rc = psy_register_thermal(psy);
 259         if (rc)
 260                 goto register_thermal_failed;
 261
 262         rc = power_supply_create_triggers(psy);
 263         if (rc)
 264                 goto create_triggers_failed;
 265
 266         power_supply_changed(psy);
 267
 268         goto success;
 269
 270 create_triggers_failed:
 271         psy_unregister_thermal(psy);
 272 register_thermal_failed:
 273         device_del(dev);
 274 kobject_set_name_failed:
 275 device_add_failed:
 276         put_device(dev);
 277 success:
 278         return rc;
 279 }
 280 EXPORT_SYMBOL_GPL(power_supply_register);
 281
 282 void power_supply_unregister(struct power_supply *psy)
 283 {
 284         cancel_work_sync(&psy->changed_work);
 285         sysfs_remove_link(&psy->dev->kobj, "powers");
 286         power_supply_remove_triggers(psy);
 287         psy_unregister_thermal(psy);
 288         device_unregister(psy->dev);
 289 }
 290 EXPORT_SYMBOL_GPL(power_supply_unregister);
 291
 292 static int __init power_supply_class_init(void)
 293 {
 294         power_supply_class = class_create(THIS_MODULE, "power_supply");
 295
 296         if (IS_ERR(power_supply_class))
 297                 return PTR_ERR(power_supply_class);
 298
 299         power_supply_class->dev_uevent = power_supply_uevent;
 300         power_supply_init_attrs(&power_supply_dev_type);
 301
 302         return 0;
 303 }
 304
 305 static void __exit power_supply_class_exit(void)
 306 {
 307         class_destroy(power_supply_class);
 308 }
 309
 310 subsys_initcall(power_supply_class_init);
 311 module_exit(power_supply_class_exit);
 312
 313 MODULE_DESCRIPTION("Universal power supply monitor class");
 314 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 315               "Szabolcs Gyurko, "
 316               "Anton Vorontsov <cbou@mail.ru>");
 317 MODULE_LICENSE("GPL");