diff --git a/src/mainboard/asrock/fatal1ty_z87_professional/Makefile.mk b/src/mainboard/asrock/fatal1ty_z87_professional/Makefile.mk
index de5aa51b34..93f729d787 100644
--- a/src/mainboard/asrock/fatal1ty_z87_professional/Makefile.mk
+++ b/src/mainboard/asrock/fatal1ty_z87_professional/Makefile.mk
@@ -4,5 +4,3 @@ bootblock-y += bootblock.c
 bootblock-y += gpio.c
 romstage-y += gpio.c
 ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-mainboard.ads
-smm-y += nuvoton.c
-ramstage-y += nuvoton.c
diff --git a/src/mainboard/asrock/fatal1ty_z87_professional/nuvoton.c b/src/mainboard/asrock/fatal1ty_z87_professional/nuvoton.c
deleted file mode 100644
index 56453329cb..0000000000
--- a/src/mainboard/asrock/fatal1ty_z87_professional/nuvoton.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#include <device/pnp_ops.h>
-#include <superio/nuvoton/common/nuvoton.h>
-#include <superio/nuvoton/nct6776/nct6776.h>
-
-#define NUVOTON_ENTRY_KEY 0x87
-#define NUVOTON_EXIT_KEY 0xAA
-
-/* Enable configuration: pass entry key '0x87' into index port dev
- * two times. */
-void nuvoton_pnp_enter_conf_state(pnp_devfn_t dev)
-{
-	u16 port = dev >> 8;
-	outb(NUVOTON_ENTRY_KEY, port);
-	outb(NUVOTON_ENTRY_KEY, port);
-}
-
-/* Disable configuration: pass exit key '0xAA' into index port dev. */
-void nuvoton_pnp_exit_conf_state(pnp_devfn_t dev)
-{
-	u16 port = dev >> 8;
-	outb(NUVOTON_EXIT_KEY, port);
-}
diff --git a/src/mainboard/asrock/z87_extreme4/Makefile.mk b/src/mainboard/asrock/z87_extreme4/Makefile.mk
index 58368c333e..c3cf55d397 100644
--- a/src/mainboard/asrock/z87_extreme4/Makefile.mk
+++ b/src/mainboard/asrock/z87_extreme4/Makefile.mk
@@ -4,5 +4,3 @@ bootblock-y += bootblock.c
 bootblock-y += gpio.c
 romstage-y += gpio.c
 ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-mainboard.ads
-ramstage-y += nuvoton.c
-smm-y += nuvoton.c
diff --git a/src/mainboard/asrock/z87_extreme4/nuvoton.c b/src/mainboard/asrock/z87_extreme4/nuvoton.c
deleted file mode 100644
index 56453329cb..0000000000
--- a/src/mainboard/asrock/z87_extreme4/nuvoton.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#include <device/pnp_ops.h>
-#include <superio/nuvoton/common/nuvoton.h>
-#include <superio/nuvoton/nct6776/nct6776.h>
-
-#define NUVOTON_ENTRY_KEY 0x87
-#define NUVOTON_EXIT_KEY 0xAA
-
-/* Enable configuration: pass entry key '0x87' into index port dev
- * two times. */
-void nuvoton_pnp_enter_conf_state(pnp_devfn_t dev)
-{
-	u16 port = dev >> 8;
-	outb(NUVOTON_ENTRY_KEY, port);
-	outb(NUVOTON_ENTRY_KEY, port);
-}
-
-/* Disable configuration: pass exit key '0xAA' into index port dev. */
-void nuvoton_pnp_exit_conf_state(pnp_devfn_t dev)
-{
-	u16 port = dev >> 8;
-	outb(NUVOTON_EXIT_KEY, port);
-}
diff --git a/src/superio/nuvoton/common/early_serial.c b/src/superio/nuvoton/common/early_serial.c
index f86e7a27d0..f0162a8f9d 100644
--- a/src/superio/nuvoton/common/early_serial.c
+++ b/src/superio/nuvoton/common/early_serial.c
@@ -2,21 +2,6 @@
 
 /*
  * A generic romstage (pre-ram) driver for Nuvoton variant Super I/O chips.
- *
- * The following is derived directly from the vendor Nuvoton's data-sheets:
- *
- * To toggle between `configuration mode` and `normal operation mode` as to
- * manipulate the various LDN's in Nuvoton Super I/O's we are required to
- * pass magic numbers `passwords keys`.
- *
- *  NUVOTON_ENTRY_KEY :=  enable  configuration : 0x87
- *  NUVOTON_EXIT_KEY  :=  disable configuration : 0xAA
- *
- * To modify a LDN's configuration register, we use the index port to select
- * the index of the LDN and then write to the data port to alter the
- * parameters. A default index, data port pair is 0x4E, 0x4F respectively, a
- * user modified pair is 0x2E, 0x2F respectively.
- *
  */
 
 #include <arch/io.h>
@@ -25,25 +10,6 @@
 #include <stdint.h>
 #include "nuvoton.h"
 
-#define NUVOTON_ENTRY_KEY 0x87
-#define NUVOTON_EXIT_KEY 0xAA
-
-/* Enable configuration: pass entry key '0x87' into index port dev
- * two times. */
-void nuvoton_pnp_enter_conf_state(pnp_devfn_t dev)
-{
-	u16 port = dev >> 8;
-	outb(NUVOTON_ENTRY_KEY, port);
-	outb(NUVOTON_ENTRY_KEY, port);
-}
-
-/* Disable configuration: pass exit key '0xAA' into index port dev. */
-void nuvoton_pnp_exit_conf_state(pnp_devfn_t dev)
-{
-	u16 port = dev >> 8;
-	outb(NUVOTON_EXIT_KEY, port);
-}
-
 /* Bring up early serial debugging output before the RAM is initialized. */
 void nuvoton_enable_serial(pnp_devfn_t dev, u16 iobase)
 {
diff --git a/src/superio/nuvoton/common/nuvoton.h b/src/superio/nuvoton/common/nuvoton.h
index 0243c69b3e..77eafeb240 100644
--- a/src/superio/nuvoton/common/nuvoton.h
+++ b/src/superio/nuvoton/common/nuvoton.h
@@ -7,8 +7,32 @@
 #include <device/pnp_type.h>
 #include <stdint.h>
 
-void nuvoton_pnp_enter_conf_state(pnp_devfn_t dev);
-void nuvoton_pnp_exit_conf_state(pnp_devfn_t dev);
+#if ENV_PNP_SIMPLE_DEVICE
+#include <device/pnp_ops.h>
+
+/*
+ * To toggle between `configuration mode` and `normal operation mode` as to
+ * manipulate the various LDN's in Nuvoton Super I/O's we are required to
+ * pass magic numbers `passwords keys`.
+ */
+#define NUVOTON_ENTRY_KEY 0x87
+#define NUVOTON_EXIT_KEY 0xAA
+
+static __always_inline void nuvoton_pnp_enter_conf_state(pnp_devfn_t dev)
+{
+	u16 port = dev >> 8;
+	outb(NUVOTON_ENTRY_KEY, port);
+	outb(NUVOTON_ENTRY_KEY, port);
+}
+
+static __always_inline void nuvoton_pnp_exit_conf_state(pnp_devfn_t dev)
+{
+	u16 port = dev >> 8;
+	outb(NUVOTON_EXIT_KEY, port);
+}
+
+#endif /* SIMPLE_DEVICE */
+
 void nuvoton_enable_serial(pnp_devfn_t dev, u16 iobase);
 #endif