diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c
index b56ff2e..78a1db2 100644
--- a/drivers/gpio/gpio-gpio-mm.c
+++ b/drivers/gpio/gpio-gpio-mm.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * GPIO driver for the Diamond Systems GPIO-MM
  * Copyright (C) 2016 William Breathitt Gray
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
  * This driver supports the following Diamond Systems devices: GPIO-MM and
  * GPIO-MM-12.
  */
@@ -211,7 +203,7 @@
 		port_state = inb(gpiommgpio->base + ports[i]);
 
 		/* store acquired bits at respective bits array offset */
-		bits[word_index] |= port_state << word_offset;
+		bits[word_index] |= (port_state << word_offset) & word_mask;
 	}
 
 	return 0;