diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common.h b/drivers/pinctrl/mediatek/pinctrl-mtk-common.h
index 69af5a7..86559f0 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common.h
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common.h
@@ -176,6 +176,8 @@
 
 extern const struct pinctrl_ops mtk_pinctrl_ops;
 
+/* A common read-modify-write helper for MediaTek chips */
+void mtk_rmw(struct udevice *dev, u32 reg, u32 mask, u32 set);
 int mtk_pinctrl_common_probe(struct udevice *dev,
 			     struct mtk_pinctrl_soc *soc);