sysfs.h: add BIN_ATTR macro

This makes it easier to create static binary attributes, which is needed
in a number of drivers, instead of "open coding" them.
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/sysfs.h

@@ -132,6 +132,15 @@ struct bin_attribute {
  */
 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
 
+/* macro to create static binary attributes easier */
+#define BIN_ATTR(_name, _mode, _read, _write, _size)		\
+struct bin_attribute bin_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.read	= _read,					\
+	.write	= _write,					\
+	.size	= _size,					\
+}
+
 struct sysfs_ops {
 	ssize_t	(*show)(struct kobject *, struct attribute *,char *);
 	ssize_t	(*store)(struct kobject *,struct attribute *,const char *, size_t);