diff --git a/sys/dev/gpio/acpi_gpiobus.c b/sys/dev/gpio/acpi_gpiobus.c
--- a/sys/dev/gpio/acpi_gpiobus.c
+++ b/sys/dev/gpio/acpi_gpiobus.c
@@ -36,6 +36,7 @@
 
 #include <dev/gpio/gpiobusvar.h>
 #include <dev/gpio/acpi_gpiobusvar.h>
+#include <dev/gpio/gpiobus_internal.h>
 
 #include "gpiobus_if.h"
 
diff --git a/sys/dev/gpio/gpiobus.c b/sys/dev/gpio/gpiobus.c
--- a/sys/dev/gpio/gpiobus.c
+++ b/sys/dev/gpio/gpiobus.c
@@ -39,6 +39,7 @@
 #include <sys/sbuf.h>
 
 #include <dev/gpio/gpiobusvar.h>
+#include <dev/gpio/gpiobus_internal.h>
 
 #include "gpiobus_if.h"
 
diff --git a/sys/dev/gpio/gpiobus_internal.h b/sys/dev/gpio/gpiobus_internal.h
new file mode 100644
--- /dev/null
+++ b/sys/dev/gpio/gpiobus_internal.h
@@ -0,0 +1,47 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#ifndef __GPIOBUS_INTERNAL_H__
+#define __GPIOBUS_INTERNAL_H__
+
+/*
+ * Functions shared between gpiobus and other bus classes that derive from it;
+ * these should not be called directly by other drivers.
+ */
+int gpiobus_attach(device_t);
+int gpiobus_detach(device_t);
+int gpiobus_init_softc(device_t);
+int gpiobus_alloc_ivars(struct gpiobus_ivar *);
+void gpiobus_free_ivars(struct gpiobus_ivar *);
+int gpiobus_read_ivar(device_t, device_t, int, uintptr_t *);
+int gpiobus_acquire_pin(device_t, uint32_t);
+int gpiobus_release_pin(device_t, uint32_t);
+
+extern driver_t gpiobus_driver;
+#endif
diff --git a/sys/dev/gpio/gpiobusvar.h b/sys/dev/gpio/gpiobusvar.h
--- a/sys/dev/gpio/gpiobusvar.h
+++ b/sys/dev/gpio/gpiobusvar.h
@@ -168,22 +168,8 @@
 struct resource *gpio_alloc_intr_resource(device_t consumer_dev, int *rid,
     u_int alloc_flags, gpio_pin_t pin, uint32_t intr_mode);
 
-/*
- * Functions shared between gpiobus and other bus classes that derive from it;
- * these should not be called directly by other drivers.
- */
 int gpio_check_flags(uint32_t, uint32_t);
 device_t gpiobus_attach_bus(device_t);
 int gpiobus_detach_bus(device_t);
-int gpiobus_attach(device_t);
-int gpiobus_detach(device_t);
-int gpiobus_init_softc(device_t);
-int gpiobus_alloc_ivars(struct gpiobus_ivar *);
-void gpiobus_free_ivars(struct gpiobus_ivar *);
-int gpiobus_read_ivar(device_t, device_t, int, uintptr_t *);
-int gpiobus_acquire_pin(device_t, uint32_t);
-int gpiobus_release_pin(device_t, uint32_t);
-
-extern driver_t gpiobus_driver;
 
 #endif	/* __GPIOBUS_H__ */
diff --git a/sys/dev/gpio/ofw_gpiobus.c b/sys/dev/gpio/ofw_gpiobus.c
--- a/sys/dev/gpio/ofw_gpiobus.c
+++ b/sys/dev/gpio/ofw_gpiobus.c
@@ -36,6 +36,7 @@
 #include <sys/module.h>
 
 #include <dev/gpio/gpiobusvar.h>
+#include <dev/gpio/gpiobus_internal.h>
 #include <dev/ofw/ofw_bus.h>
 
 #include "gpiobus_if.h"