v4.19.13 snapshot.
diff --git a/arch/mips/ath79/dev-gpio-buttons.h b/arch/mips/ath79/dev-gpio-buttons.h
new file mode 100644
index 0000000..481847a
--- /dev/null
+++ b/arch/mips/ath79/dev-gpio-buttons.h
@@ -0,0 +1,23 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO button support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  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.
+ */
+
+#ifndef _ATH79_DEV_GPIO_BUTTONS_H
+#define _ATH79_DEV_GPIO_BUTTONS_H
+
+#include <linux/input.h>
+#include <linux/gpio_keys.h>
+
+void ath79_register_gpio_keys_polled(int id,
+				     unsigned poll_interval,
+				     unsigned nbuttons,
+				     struct gpio_keys_button *buttons);
+
+#endif /* _ATH79_DEV_GPIO_BUTTONS_H */