parport: Introduce module_parport_driver() helper macro

Introduce module_parport_driver() helper macro to reduce boilerplate
in the existing and new code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210303091642.23929-2-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/linux/parport.h

@@ -332,9 +332,19 @@ int __must_check __parport_register_driver(struct parport_driver *,
 	__parport_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
 
 /* Unregister a high-level driver. */
-extern void parport_unregister_driver (struct parport_driver *);
 void parport_unregister_driver(struct parport_driver *);
 
+/**
+ * module_parport_driver() - Helper macro for registering a modular parport driver
+ * @__parport_driver: struct parport_driver to be used
+ *
+ * Helper macro for parport drivers which do not do anything special in module
+ * init and exit. This eliminates a lot of boilerplate. Each module may only
+ * use this macro once, and calling it replaces module_init() and module_exit().
+ */
+#define module_parport_driver(__parport_driver) \
+	module_driver(__parport_driver, parport_register_driver, parport_unregister_driver)
+
 /* If parport_register_driver doesn't fit your needs, perhaps
  * parport_find_xxx does. */
 extern struct parport *parport_find_number (int);