diff --git a/sys/dev/superio/superio.c b/sys/dev/superio/superio.c
index da4dd112533..24dc67b3d4f 100644
--- a/sys/dev/superio/superio.c
+++ b/sys/dev/superio/superio.c
@@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$");
 #include <isa/isavar.h>
 
 #include <dev/superio/superio.h>
+#include <dev/superio/superio_io.h>
 
 #include "isa_if.h"
 
@@ -84,6 +85,7 @@ struct siosc {
 	struct mtx			conf_lock;
 	STAILQ_HEAD(, superio_devinfo)	devlist;
 	struct resource*		io_res;
+	struct cdev			*chardev;
 	int				io_rid;
 	uint16_t			io_port;
 	const struct sio_conf_methods	*methods;
@@ -96,6 +98,14 @@ struct siosc {
 	uint8_t				enable_reg;
 };
 
+static	d_ioctl_t	superio_ioctl;
+
+static struct cdevsw superio_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_ioctl =	superio_ioctl,
+	.d_name =	"superio",
+};
+
 #define NUMPORTS	2
 
 static uint8_t
@@ -621,6 +631,12 @@ superio_attach(device_t dev)
 
 	bus_generic_probe(dev);
 	bus_generic_attach(dev);
+
+	sc->chardev = make_dev(&superio_cdevsw, device_get_unit(dev),
+	    UID_ROOT, GID_WHEEL, 0600, "superio%d", device_get_unit(dev));
+	if (sc->chardev == NULL)
+		device_printf(dev, "failed to create character device\n");
+	sc->chardev->si_drv1 = sc;
 	return (0);
 }
 
@@ -633,6 +649,8 @@ superio_detach(device_t dev)
 	error = bus_generic_detach(dev);
 	if (error != 0)
 		return (error);
+	if (sc->chardev != NULL)
+		destroy_dev(sc->chardev);
 	device_delete_children(dev);
 	bus_release_resource(dev, SYS_RES_IOPORT, sc->io_rid, sc->io_res);
 	mtx_destroy(&sc->conf_lock);
@@ -915,6 +933,31 @@ superio_find_dev(device_t superio, superio_dev_type_t type, int ldn)
 	return (NULL);
 }
 
+static int
+superio_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
+    struct thread *td)
+{
+	struct siosc *sc;
+	struct superiocmd *s;
+
+	sc = dev->si_drv1;
+	s = (struct superiocmd *)data;
+	switch (cmd) {
+	case SUPERIO_CR_READ:
+		sio_conf_enter(sc);
+		s->val = sio_ldn_read(sc, s->ldn, s->cr);
+		sio_conf_exit(sc);
+		return (0);
+	case SUPERIO_CR_WRITE:
+		sio_conf_enter(sc);
+		sio_ldn_write(sc, s->ldn, s->cr, s->val);
+		sio_conf_exit(sc);
+		return (0);
+	default:
+		return (ENOTTY);
+	}
+}
+
 static devclass_t superio_devclass;
 
 static device_method_t superio_methods[] = {
diff --git a/sys/dev/superio/superio_io.h b/sys/dev/superio/superio_io.h
new file mode 100644
index 00000000000..e1e4026fd9c
--- /dev/null
+++ b/sys/dev/superio/superio_io.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2019 Andriy Gapon
+ *
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef SUPERIO_IO_H
+#define SUPERIO_IO_H
+
+#include <sys/types.h>
+
+struct superiocmd {
+	uint8_t	ldn;
+	uint8_t	cr;
+	uint8_t	val;
+};
+
+#define SUPERIO_CR_READ		_IOWR('s', 0, struct superiocmd)
+#define SUPERIO_CR_WRITE	_IOW('s', 1, struct superiocmd)
+
+#endif /*SUPERIO_IO_H*/