extcon: add possibility to get extcon device by OF node

Since extcon property is not allowed in DT, extcon subsystem requires
another way to get extcon device. Lets try the simplest approach - get
edev by of_node.

Signed-off-by: Andrzej Hajda <[email protected]>
Acked-by: Chanwoo Choi <[email protected]>
Signed-off-by: Chanwoo Choi <[email protected]>

Author: Andrzej Hajda

drivers/extcon/extcon.c

@@ -1336,6 +1336,28 @@ void extcon_dev_unregister(struct extcon_dev *edev)
 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 
 #ifdef CONFIG_OF
+
+/*
+ * extcon_find_edev_by_node - Find the extcon device from devicetree.
+ * @node	: OF node identifying edev
+ *
+ * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
+ */
+struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
+{
+	struct extcon_dev *edev;
+
+	mutex_lock(&extcon_dev_list_lock);
+	list_for_each_entry(edev, &extcon_dev_list, entry)
+		if (edev->dev.parent && edev->dev.parent->of_node == node)
+			goto out;
+	edev = ERR_PTR(-EPROBE_DEFER);
+out:
+	mutex_unlock(&extcon_dev_list_lock);
+
+	return edev;
+}
+
 /*
  * extcon_get_edev_by_phandle - Get the extcon device from devicetree.
  * @dev		: the instance to the given device
@@ -1363,25 +1385,27 @@ struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 		return ERR_PTR(-ENODEV);
 	}
 
-	mutex_lock(&extcon_dev_list_lock);
-	list_for_each_entry(edev, &extcon_dev_list, entry) {
-		if (edev->dev.parent && edev->dev.parent->of_node == node) {
-			mutex_unlock(&extcon_dev_list_lock);
-			of_node_put(node);
-			return edev;
-		}
-	}
-	mutex_unlock(&extcon_dev_list_lock);
+	edev = extcon_find_edev_by_node(node);
 	of_node_put(node);
 
-	return ERR_PTR(-EPROBE_DEFER);
+	return edev;
 }
+
 #else
+
+struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 {
 	return ERR_PTR(-ENOSYS);
 }
+
 #endif /* CONFIG_OF */
+
+EXPORT_SYMBOL_GPL(extcon_find_edev_by_node);
 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
 
 /**

include/linux/extcon.h

@@ -230,6 +230,7 @@ extern void devm_extcon_unregister_notifier_all(struct device *dev,
  * Following APIs get the extcon_dev from devicetree or by through extcon name.
  */
 extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
+extern struct extcon_dev *extcon_find_edev_by_node(struct device_node *node);
 extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
 						     int index);
 
@@ -283,6 +284,11 @@ static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 	return ERR_PTR(-ENODEV);
 }
 
+static inline struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
 				int index)
 {