-/**
- * extcon_register_interest() - Register a notifier for a state change of a
- * specific cable, not an entier set of cables of a
- * extcon device.
- * @obj: an empty extcon_specific_cable_nb object to be returned.
- * @extcon_name: the name of extcon device.
- * if NULL, extcon_register_interest will register
- * every cable with the target cable_name given.
- * @cable_name: the target cable name.
- * @nb: the notifier block to get notified.
- *
- * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
- * the struct for you.
- *
- * extcon_register_interest is a helper function for those who want to get
- * notification for a single specific cable's status change. If a user wants
- * to get notification for any changes of all cables of a extcon device,
- * he/she should use the general extcon_register_notifier().
- *
- * Note that the second parameter given to the callback of nb (val) is
- * "old_state", not the current state. The current state can be retrieved
- * by looking at the third pameter (edev pointer)'s state value.
- */
-int extcon_register_interest(struct extcon_specific_cable_nb *obj,
- const char *extcon_name, const char *cable_name,
- struct notifier_block *nb)
-{
- unsigned long flags;
- int ret;
-
- if (!obj || !cable_name || !nb)
- return -EINVAL;
-
- if (extcon_name) {
- obj->edev = extcon_get_extcon_dev(extcon_name);
- if (!obj->edev)
- return -ENODEV;
-
- obj->cable_index = find_cable_index_by_name(obj->edev,
- cable_name);
- if (obj->cable_index < 0)
- return obj->cable_index;
-
- obj->user_nb = nb;
-
- spin_lock_irqsave(&obj->edev->lock, flags);
- ret = raw_notifier_chain_register(
- &obj->edev->nh[obj->cable_index],
- obj->user_nb);
- spin_unlock_irqrestore(&obj->edev->lock, flags);
- } else {
- struct class_dev_iter iter;
- struct extcon_dev *extd;
- struct device *dev;
-
- if (!extcon_class)
- return -ENODEV;
- class_dev_iter_init(&iter, extcon_class, NULL, NULL);
- while ((dev = class_dev_iter_next(&iter))) {
- extd = dev_get_drvdata(dev);
-
- if (find_cable_index_by_name(extd, cable_name) < 0)
- continue;
-
- class_dev_iter_exit(&iter);
- return extcon_register_interest(obj, extd->name,
- cable_name, nb);
- }
-
- ret = -ENODEV;
- }
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(extcon_register_interest);
-
-/**
- * extcon_unregister_interest() - Unregister the notifier registered by
- * extcon_register_interest().
- * @obj: the extcon_specific_cable_nb object returned by
- * extcon_register_interest().
- */
-int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
-{
- unsigned long flags;
- int ret;
-
- if (!obj)
- return -EINVAL;
-
- spin_lock_irqsave(&obj->edev->lock, flags);
- ret = raw_notifier_chain_unregister(
- &obj->edev->nh[obj->cable_index], obj->user_nb);
- spin_unlock_irqrestore(&obj->edev->lock, flags);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(extcon_unregister_interest);
-