Index: arch/arm/broadcom/bcm2835_gpio.c
===================================================================
RCS file: /home/netbsd/src/sys/arch/arm/broadcom/bcm2835_gpio.c,v
retrieving revision 1.7
diff -p -u -r1.7 bcm2835_gpio.c
--- arch/arm/broadcom/bcm2835_gpio.c	19 May 2018 14:02:10 -0000	1.7
+++ arch/arm/broadcom/bcm2835_gpio.c	28 Jul 2018 14:51:25 -0000
@@ -94,6 +94,8 @@ struct bcmgpio_softc {
 	device_t		sc_dev;
 	bus_space_tag_t		sc_iot;
 	bus_space_handle_t	sc_ioh;
+	bus_addr_t		sc_addr;
+	bus_size_t		sc_size;
 	struct gpio_chipset_tag	sc_gpio_gc;
 
 	kmutex_t		sc_lock;
@@ -113,6 +115,7 @@ struct bcmgpio_pin {
 static int	bcmgpio_match(device_t, cfdata_t, void *);
 static void	bcmgpio_attach(device_t, device_t, void *);
 
+static paddr_t	bcm2835gpio_gpio_mmap(void *, off_t, int);
 static int	bcm2835gpio_gpio_pin_read(void *, int);
 static void	bcm2835gpio_gpio_pin_write(void *, int, int);
 static void	bcm2835gpio_gpio_pin_ctl(void *, int, int);
@@ -248,15 +251,13 @@ bcmgpio_attach(device_t parent, device_t
 	struct bcmgpio_softc * const sc = device_private(self);
 	struct fdt_attach_args * const faa = aux;
 	struct gpiobus_attach_args gba;
-	bus_addr_t addr;
-	bus_size_t size;
 	u_int func;
 	int error;
 	int pin;
 	int bank;
 
 	const int phandle = faa->faa_phandle;
-	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
+	if (fdtbus_get_reg(phandle, 0, &sc->sc_addr, &sc->sc_size) != 0) {
 		aprint_error(": couldn't get registers\n");
 		return;
 	}
@@ -267,7 +268,8 @@ bcmgpio_attach(device_t parent, device_t
 	aprint_normal(": GPIO controller\n");
 
 	sc->sc_iot = faa->faa_bst;
-	error = bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh);
+	error = bus_space_map(sc->sc_iot, sc->sc_addr, sc->sc_size, 0,
+	    &sc->sc_ioh);
 	if (error) {
 		aprint_error_dev(self, "couldn't map registers\n");
 		return;
@@ -352,6 +354,7 @@ bcmgpio_attach(device_t parent, device_t
 
 	/* create controller tag */
 	sc->sc_gpio_gc.gp_cookie = sc;
+	sc->sc_gpio_gc.gp_gc_mmap = bcm2835gpio_gpio_mmap;
 	sc->sc_gpio_gc.gp_pin_read = bcm2835gpio_gpio_pin_read;
 	sc->sc_gpio_gc.gp_pin_write = bcm2835gpio_gpio_pin_write;
 	sc->sc_gpio_gc.gp_pin_ctl = bcm2835gpio_gpio_pin_ctl;
@@ -687,6 +690,18 @@ bcmgpio_fdt_intrstr(device_t dev, u_int 
 }
 
 /* GPIO support functions */
+static paddr_t
+bcm2835gpio_gpio_mmap(void *arg, off_t off, int prot)
+{
+	struct bcmgpio_softc *sc = arg;
+
+	if (off < 0 || off >= sc->sc_size)
+		return (paddr_t)-1;
+
+	return bus_space_mmap(sc->sc_iot, sc->sc_addr, off, prot,
+	    BUS_SPACE_MAP_LINEAR);
+}
+
 static int
 bcm2835gpio_gpio_pin_read(void *arg, int pin)
 {
Index: dev/gpio/gpio.c
===================================================================
RCS file: /home/netbsd/src/sys/dev/gpio/gpio.c,v
retrieving revision 1.61
diff -p -u -r1.61 gpio.c
--- dev/gpio/gpio.c	19 May 2018 13:59:06 -0000	1.61
+++ dev/gpio/gpio.c	28 Jul 2018 10:47:12 -0000
@@ -99,6 +99,7 @@ dev_type_open(gpioopen);
 dev_type_close(gpioclose);
 dev_type_ioctl(gpioioctl);
 dev_type_ioctl(gpioioctl_locked);
+dev_type_mmap(gpiommap);
 
 const struct cdevsw gpio_cdevsw = {
 	.d_open = gpioopen,
@@ -109,7 +110,7 @@ const struct cdevsw gpio_cdevsw = {
 	.d_stop = nostop,
 	.d_tty = notty,
 	.d_poll = nopoll,
-	.d_mmap = nommap,
+	.d_mmap = gpiommap,
 	.d_kqfilter = nokqfilter,
 	.d_discard = nodiscard,
 	.d_flag = D_OTHER | D_MPSAFE
@@ -659,6 +660,15 @@ gpio_pinbyname(struct gpio_softc *sc, ch
         return -1;
 }
 
+paddr_t
+gpiommap(dev_t dev, off_t off, int prot)
+{
+	struct gpio_softc *sc;
+
+	sc = device_lookup_private(&gpio_cd, minor(dev));
+	return gpiobus_mmap(sc->sc_gc, off, prot);
+}
+
 int
 gpioioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
 {
Index: dev/gpio/gpiovar.h
===================================================================
RCS file: /home/netbsd/src/sys/dev/gpio/gpiovar.h,v
retrieving revision 1.18
diff -p -u -r1.18 gpiovar.h
--- dev/gpio/gpiovar.h	19 May 2018 13:59:06 -0000	1.18
+++ dev/gpio/gpiovar.h	28 Jul 2018 10:09:19 -0000
@@ -28,6 +28,7 @@ typedef struct gpio_chipset_tag {
 
 	int	(*gp_gc_open)(void *, device_t);
 	void    (*gp_gc_close)(void *, device_t);
+	paddr_t (*gp_gc_mmap)(void *, off_t, int);
 	int	(*gp_pin_read)(void *, int);
 	void	(*gp_pin_write)(void *, int, int);
 	void	(*gp_pin_ctl)(void *, int, int);
@@ -64,6 +65,9 @@ int gpiobus_print(void *, const char *);
     ((gc)->gp_gc_open ? ((gc)->gp_gc_open((gc)->gp_cookie, dev)) : 0)
 #define gpiobus_close(gc, dev) \
     ((gc)->gp_gc_close ? ((gc)->gp_gc_close((gc)->gp_cookie, dev)), 1 : 0)
+#define gpiobus_mmap(gc, off, prot) \
+    ((gc)->gp_gc_mmap ? ((gc)->gp_gc_mmap((gc)->gp_cookie, off, prot)) : \
+	(paddr_t)-1)
 #define gpiobus_pin_read(gc, pin) \
     ((gc)->gp_pin_read((gc)->gp_cookie, (pin)))
 #define gpiobus_pin_write(gc, pin, value) \