extcon: Modify the device name as extcon[X] for sysfs

This patch modify the device name as extcon[X] for sysfs by using the 'extcon'
prefix word instead of separate device name. On user-space aspect, user would
find the some extcon drvier with extcon[X] pattern. So, this patch modify the
device name as following:
- /sys/class/extcon/[device name] -> /sys/class/extcon/extcon[X]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/extcon/extcon.c

@@ -163,7 +163,7 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 			return ret;
 	}
 
-	return sprintf(buf, "%s\n", dev_name(&edev->dev));
+	return sprintf(buf, "%s\n", edev->name);
 }
 static DEVICE_ATTR_RO(name);
 
@@ -701,6 +701,7 @@ EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 int extcon_dev_register(struct extcon_dev *edev)
 {
 	int ret, index = 0;
+	static atomic_t edev_no = ATOMIC_INIT(-1);
 
 	if (!extcon_class) {
 		ret = create_extcon_class();
@@ -725,13 +726,14 @@ int extcon_dev_register(struct extcon_dev *edev)
 	edev->dev.class = extcon_class;
 	edev->dev.release = extcon_dev_release;
 
-	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
+	edev->name = dev_name(edev->dev.parent);
 	if (IS_ERR_OR_NULL(edev->name)) {
 		dev_err(&edev->dev,
 			"extcon device name is null\n");
 		return -EINVAL;
 	}
-	dev_set_name(&edev->dev, "%s", edev->name);
+	dev_set_name(&edev->dev, "extcon%lu",
+			(unsigned long)atomic_inc_return(&edev_no));
 
 	if (edev->max_supported) {
 		char buf[10];