driverfs: Declare DEVICE_ATTR macro for initializing device attributes

(hide internal format of the structure)

include/linux/driverfs_fs.h

@@ -37,11 +37,18 @@ struct device;
 struct device_attribute {
 	char			* name;
 	mode_t			mode;
-
 	ssize_t (*show)(struct device * dev, char * buf, size_t count, loff_t off);
 	ssize_t (*store)(struct device * dev, const char * buf, size_t count, loff_t off);
 };
 
+#define DEVICE_ATTR(_name,_str,_mode,_show,_store) \
+struct device_attribute dev_attr_##_name = { \
+	.name	= _str,		\
+	.mode	= _mode,	\
+	.show	= _show,	\
+	.store	= _store,	\
+};
+
 extern int
 driverfs_create_dir(struct driver_dir_entry *, struct driver_dir_entry *);