/*
   *  Universal power supply monitor class
   *
   *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
   *  Copyright © 2004  Szabolcs Gyurko
   *  Copyright © 2003  Ian Molton <spyro@f2s.com>
   *
   *  Modified: 2004, Oct     Szabolcs Gyurko
   *
   *  You may use this code as per GPL version 2
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/init.h>

  #include <linux/slab.h>

  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/power_supply.h>
  #include "power_supply.h"

  /* exported for the APM Power driver, APM emulation */

  struct class *power_supply_class;

  EXPORT_SYMBOL_GPL(power_supply_class);

  static struct device_type power_supply_dev_type;

  static int __power_supply_changed_work(struct device *dev, void *data)
  {
  	struct power_supply *psy = (struct power_supply *)data;
  	struct power_supply *pst = dev_get_drvdata(dev);
  	int i;
  
  	for (i = 0; i < psy->num_supplicants; i++)
  		if (!strcmp(psy->supplied_to[i], pst->name)) {
  			if (pst->external_power_changed)
  				pst->external_power_changed(pst);
  		}
  	return 0;
  }

  static void power_supply_changed_work(struct work_struct *work)
  {
  	struct power_supply *psy = container_of(work, struct power_supply,
  						changed_work);

  	dev_dbg(psy->dev, "%s
  ", __func__);

  	class_for_each_device(power_supply_class, NULL, psy,

  			      __power_supply_changed_work);

  
  	power_supply_update_leds(psy);
  
  	kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);

  }
  
  void power_supply_changed(struct power_supply *psy)
  {

  	dev_dbg(psy->dev, "%s
  ", __func__);

  
  	schedule_work(&psy->changed_work);

  }

  EXPORT_SYMBOL_GPL(power_supply_changed);

  static int __power_supply_am_i_supplied(struct device *dev, void *data)

  {
  	union power_supply_propval ret = {0,};

  	struct power_supply *psy = (struct power_supply *)data;
  	struct power_supply *epsy = dev_get_drvdata(dev);
  	int i;
  
  	for (i = 0; i < epsy->num_supplicants; i++) {
  		if (!strcmp(epsy->supplied_to[i], psy->name)) {
  			if (epsy->get_property(epsy,
  				  POWER_SUPPLY_PROP_ONLINE, &ret))
  				continue;
  			if (ret.intval)
  				return ret.intval;

  		}
  	}

  	return 0;
  }
  
  int power_supply_am_i_supplied(struct power_supply *psy)
  {
  	int error;

  	error = class_for_each_device(power_supply_class, NULL, psy,

  				      __power_supply_am_i_supplied);

  	dev_dbg(psy->dev, "%s %d
  ", __func__, error);

  	return error;

  }

  EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);

  static int __power_supply_is_system_supplied(struct device *dev, void *data)
  {
  	union power_supply_propval ret = {0,};
  	struct power_supply *psy = dev_get_drvdata(dev);

  	unsigned int *count = data;

  	(*count)++;

  	if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
  		if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
  			return 0;
  		if (ret.intval)
  			return ret.intval;
  	}
  	return 0;
  }
  
  int power_supply_is_system_supplied(void)
  {
  	int error;

  	unsigned int count = 0;

  	error = class_for_each_device(power_supply_class, NULL, &count,

  				      __power_supply_is_system_supplied);

  	/*
  	 * If no power class device was found at all, most probably we are
  	 * running on a desktop system, so assume we are on mains power.
  	 */
  	if (count == 0)
  		return 1;

  	return error;
  }

  EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);

  int power_supply_set_battery_charged(struct power_supply *psy)
  {
  	if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
  		psy->set_charged(psy);
  		return 0;
  	}
  
  	return -EINVAL;
  }
  EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
  
  static int power_supply_match_device_by_name(struct device *dev, void *data)
  {
  	const char *name = data;
  	struct power_supply *psy = dev_get_drvdata(dev);
  
  	return strcmp(psy->name, name) == 0;
  }
  
  struct power_supply *power_supply_get_by_name(char *name)
  {
  	struct device *dev = class_find_device(power_supply_class, NULL, name,
  					power_supply_match_device_by_name);
  
  	return dev ? dev_get_drvdata(dev) : NULL;
  }
  EXPORT_SYMBOL_GPL(power_supply_get_by_name);

  int power_supply_powers(struct power_supply *psy, struct device *dev)
  {

  	return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");

  }
  EXPORT_SYMBOL_GPL(power_supply_powers);

  static void power_supply_dev_release(struct device *dev)
  {
  	pr_debug("device: '%s': %s
  ", dev_name(dev), __func__);
  	kfree(dev);
  }

  int power_supply_register(struct device *parent, struct power_supply *psy)
  {

  	struct device *dev;
  	int rc;

  	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  	if (!dev)
  		return -ENOMEM;

  	device_initialize(dev);

  	dev->class = power_supply_class;
  	dev->type = &power_supply_dev_type;
  	dev->parent = parent;
  	dev->release = power_supply_dev_release;
  	dev_set_drvdata(dev, psy);
  	psy->dev = dev;

  	INIT_WORK(&psy->changed_work, power_supply_changed_work);

  	rc = kobject_set_name(&dev->kobj, "%s", psy->name);
  	if (rc)
  		goto kobject_set_name_failed;
  
  	rc = device_add(dev);

  	if (rc)

  		goto device_add_failed;

  	rc = power_supply_create_triggers(psy);
  	if (rc)
  		goto create_triggers_failed;
  
  	power_supply_changed(psy);
  
  	goto success;
  
  create_triggers_failed:

  	device_del(dev);

  kobject_set_name_failed:
  device_add_failed:

  	put_device(dev);

  success:
  	return rc;
  }

  EXPORT_SYMBOL_GPL(power_supply_register);

  
  void power_supply_unregister(struct power_supply *psy)
  {

  	cancel_work_sync(&psy->changed_work);

  	sysfs_remove_link(&psy->dev->kobj, "powers");

  	power_supply_remove_triggers(psy);

  	device_unregister(psy->dev);

  }

  EXPORT_SYMBOL_GPL(power_supply_unregister);

  
  static int __init power_supply_class_init(void)
  {
  	power_supply_class = class_create(THIS_MODULE, "power_supply");
  
  	if (IS_ERR(power_supply_class))
  		return PTR_ERR(power_supply_class);
  
  	power_supply_class->dev_uevent = power_supply_uevent;

  	power_supply_init_attrs(&power_supply_dev_type);

  
  	return 0;
  }
  
  static void __exit power_supply_class_exit(void)
  {
  	class_destroy(power_supply_class);

  }

  subsys_initcall(power_supply_class_init);
  module_exit(power_supply_class_exit);
  
  MODULE_DESCRIPTION("Universal power supply monitor class");
  MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
  	      "Szabolcs Gyurko, "
  	      "Anton Vorontsov <cbou@mail.ru>");
  MODULE_LICENSE("GPL");