Index: sys/arm/at91/uart_bus_at91usart.c
===================================================================
--- sys/arm/at91/uart_bus_at91usart.c
+++ sys/arm/at91/uart_bus_at91usart.c
@@ -104,7 +104,7 @@
 	sc->sc_class = &at91_usart_class;
 	if (sc->sc_class->uc_rclk == 0)
 		sc->sc_class->uc_rclk = at91_master_clock;
-	return (uart_bus_probe(dev, 0, 0, 0, device_get_unit(dev)));
+	return (uart_bus_probe(dev, 0, 0, 0, 0, device_get_unit(dev)));
 }
 
 
Index: sys/arm/cavium/cns11xx/uart_bus_ec.c
===================================================================
--- sys/arm/cavium/cns11xx/uart_bus_ec.c
+++ sys/arm/cavium/cns11xx/uart_bus_ec.c
@@ -69,7 +69,7 @@
 
 	sc = device_get_softc(dev);
 	sc->sc_class = &uart_ns8250_class;
-	status = uart_bus_probe(dev, EC_UART_REGSHIFT, EC_UART_CLOCK, 0, 0);
+	status = uart_bus_probe(dev, EC_UART_REGSHIFT, 0, EC_UART_CLOCK, 0, 0);
 	return (status);
 }
 
Index: sys/arm/nvidia/tegra_uart.c
===================================================================
--- sys/arm/nvidia/tegra_uart.c
+++ sys/arm/nvidia/tegra_uart.c
@@ -216,7 +216,7 @@
 		device_printf(dev, "Cannot enable UART clock: %d\n", rv);
 		return (ENXIO);
 	}
-	return (uart_bus_probe(dev, shift, (int)freq, 0, 0));
+	return (uart_bus_probe(dev, shift, 0, (int)freq, 0, 0));
 }
 
 static int
Index: sys/arm/xscale/i8134x/uart_bus_i81342.c
===================================================================
--- sys/arm/xscale/i8134x/uart_bus_i81342.c
+++ sys/arm/xscale/i8134x/uart_bus_i81342.c
@@ -83,7 +83,7 @@
 	    0x40 | 0x10);
         bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
 
-	err = uart_bus_probe(dev, 2, 33334000, 0, device_get_unit(dev));
+	err = uart_bus_probe(dev, 2, 0, 33334000, 0, device_get_unit(dev));
 	sc->sc_rxfifosz = sc->sc_txfifosz = 1;
 	return (err);
 }
Index: sys/arm/xscale/ixp425/uart_bus_ixp425.c
===================================================================
--- sys/arm/xscale/ixp425/uart_bus_ixp425.c
+++ sys/arm/xscale/ixp425/uart_bus_ixp425.c
@@ -78,5 +78,5 @@
 	if (bootverbose)
 		device_printf(dev, "rclk %u\n", rclk);
 
-	return uart_bus_probe(dev, 0, rclk, 0, 0);
+	return uart_bus_probe(dev, 0, 0, rclk, 0, 0);
 }
Index: sys/arm/xscale/pxa/uart_bus_pxa.c
===================================================================
--- sys/arm/xscale/pxa/uart_bus_pxa.c
+++ sys/arm/xscale/pxa/uart_bus_pxa.c
@@ -97,7 +97,7 @@
 	sc = device_get_softc(dev);
 	sc->sc_class = &uart_ns8250_class;
 
-	return(uart_bus_probe(dev, 2, PXA2X0_COM_FREQ, 0, 0));
+	return(uart_bus_probe(dev, 2, 0, PXA2X0_COM_FREQ, 0, 0));
 }
 
 DRIVER_MODULE(uart, pxa, uart_pxa_driver, uart_devclass, 0, 0);
Index: sys/dev/uart/uart.h
===================================================================
--- sys/dev/uart/uart.h
+++ sys/dev/uart/uart.h
@@ -41,14 +41,48 @@
 	u_int	chan;
 	u_int	rclk;
 	u_int	regshft;
+	u_int	regiowidth;
 };
 
 #define	uart_regofs(bas, reg)		((reg) << (bas)->regshft)
+#define	uart_regiowidth(bas)		((bas)->regiowidth)
 
-#define	uart_getreg(bas, reg)		\
-	bus_space_read_1((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
-#define	uart_setreg(bas, reg, value)	\
-	bus_space_write_1((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
+static inline uint32_t
+uart_getreg(struct uart_bas *bas, int reg)
+{
+	uint32_t ret;
+
+	switch (uart_regiowidth(bas)) {
+	case 4:
+		ret = bus_space_read_4(bas->bst, bas->bsh, uart_regofs(bas, reg));
+		break;
+	case 2:
+		ret = bus_space_read_2(bas->bst, bas->bsh, uart_regofs(bas, reg));
+		break;
+	default:
+		ret = bus_space_read_1(bas->bst, bas->bsh, uart_regofs(bas, reg));
+		break;
+	}
+
+	return (ret);
+}
+
+static inline void
+uart_setreg(struct uart_bas *bas, int reg, int value)
+{
+
+	switch (uart_regiowidth(bas)) {
+	case 4:
+		bus_space_write_4(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
+		break;
+	case 2:
+		bus_space_write_2(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
+		break;
+	default:
+		bus_space_write_1(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
+		break;
+	}
+}
 
 /*
  * XXX we don't know the length of the bus space address range in use by
Index: sys/dev/uart/uart_bus.h
===================================================================
--- sys/dev/uart/uart_bus.h
+++ sys/dev/uart/uart_bus.h
@@ -63,6 +63,7 @@
 	u_int	uc_range;		/* Bus space address range. */
 	u_int	uc_rclk;		/* Default rclk for this device. */
 	u_int	uc_rshift;		/* Default regshift for this device. */
+	u_int	uc_riowidth;		/* Default reg io width for this device. */
 };
 
 struct uart_softc {
@@ -137,7 +138,7 @@
 int uart_bus_resume(device_t dev);
 serdev_intr_t *uart_bus_ihand(device_t dev, int ipend);
 int uart_bus_ipend(device_t dev);
-int uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan);
+int uart_bus_probe(device_t dev, int regshft, int regiowidth, int rclk, int rid, int chan);
 int uart_bus_sysdev(device_t dev);
 
 void uart_sched_softih(struct uart_softc *, uint32_t);
Index: sys/dev/uart/uart_bus_acpi.c
===================================================================
--- sys/dev/uart/uart_bus_acpi.c
+++ sys/dev/uart/uart_bus_acpi.c
@@ -109,13 +109,13 @@
 #if defined(__i386__) || defined(__amd64__)
 	if (!ISA_PNP_PROBE(parent, dev, acpi_ns8250_ids)) {
 		sc->sc_class = &uart_ns8250_class;
-		return (uart_bus_probe(dev, 0, 0, 0, 0));
+		return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 	}
 
 	/* Add checks for non-ns8250 IDs here. */
 #elif defined(__aarch64__)
 	if ((sc->sc_class = uart_acpi_find_device(dev)) != NULL)
-		return (uart_bus_probe(dev, 2, 0, 0, 0));
+		return (uart_bus_probe(dev, 2, 0, 0, 0, 0));
 #endif
 
 	return (ENXIO);
Index: sys/dev/uart/uart_bus_ebus.c
===================================================================
--- sys/dev/uart/uart_bus_ebus.c
+++ sys/dev/uart/uart_bus_ebus.c
@@ -97,7 +97,7 @@
 				return (ENXIO);
 		}
 		sc->sc_class = &uart_ns8250_class;
-		return (uart_bus_probe(dev, 0, 0, 0, 0));
+		return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 	}
 
 	return (ENXIO);
Index: sys/dev/uart/uart_bus_fdt.c
===================================================================
--- sys/dev/uart/uart_bus_fdt.c
+++ sys/dev/uart/uart_bus_fdt.c
@@ -90,6 +90,15 @@
 	return (0);
 }
 
+int
+uart_fdt_get_io_width(phandle_t node, pcell_t *cell)
+{
+
+	if ((OF_getencprop(node, "reg-io-width", cell, sizeof(*cell))) <= 0)
+		return (-1);
+	return (0);
+}
+
 static uintptr_t
 uart_fdt_find_device(device_t dev)
 {
@@ -154,14 +163,15 @@
 
 int
 uart_cpu_fdt_probe(struct uart_class **classp, bus_space_tag_t *bst,
-    bus_space_handle_t *bsh, int *baud, u_int *rclk, u_int *shiftp)
+    bus_space_handle_t *bsh, int *baud, u_int *rclk, u_int *shiftp,
+    u_int *iowidthp)
 {
 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
 	    "stdin-path", "stdin", NULL};
 	const char **name;
 	struct uart_class *class;
 	phandle_t node, chosen;
-	pcell_t br, clk, shift;
+	pcell_t br, clk, shift, iowidth;
 	char *cp;
 	int err;
 
@@ -212,6 +222,9 @@
 	if (uart_fdt_get_shift(node, &shift) != 0)
 		shift = uart_getregshift(class);
 
+	if (uart_fdt_get_io_width(node, &iowidth) != 0)
+		iowidth = uart_getregiowidth(class);
+
 	if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
 		br = 0;
 
@@ -223,6 +236,7 @@
 	*baud = br;
 	*rclk = clk;
 	*shiftp = shift;
+	*iowidthp = iowidth;
 
 	return (0);
 }
@@ -232,7 +246,7 @@
 {
 	struct uart_softc *sc;
 	phandle_t node;
-	pcell_t clock, shift;
+	pcell_t clock, shift, iowidth;
 	int err;
 
 	sc = device_get_softc(dev);
@@ -250,8 +264,10 @@
 		return (err);
 	if (uart_fdt_get_shift(node, &shift) != 0)
 		shift = uart_getregshift(sc->sc_class);
+	if (uart_fdt_get_io_width(node, &iowidth) != 0)
+		iowidth = uart_getregiowidth(sc->sc_class);
 
-	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
+	return (uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0));
 }
 
 DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
Index: sys/dev/uart/uart_bus_isa.c
===================================================================
--- sys/dev/uart/uart_bus_isa.c
+++ sys/dev/uart/uart_bus_isa.c
@@ -165,7 +165,7 @@
 	/* Probe PnP _and_ non-PnP ns8250 here. */
 	sc->sc_class = &uart_ns8250_class;
 
-	return (uart_bus_probe(dev, 0, 0, 0, 0));
+	return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 }
 
 DRIVER_MODULE(uart, isa, uart_isa_driver, uart_devclass, 0, 0);
Index: sys/dev/uart/uart_bus_pccard.c
===================================================================
--- sys/dev/uart/uart_bus_pccard.c
+++ sys/dev/uart/uart_bus_pccard.c
@@ -93,7 +93,7 @@
 	sc = device_get_softc(dev);
 	sc->sc_class = &uart_ns8250_class;
 
-	error = uart_bus_probe(dev, 0, 0, 0, 0);
+	error = uart_bus_probe(dev, 0, 0, 0, 0, 0);
 	if (error > 0)
 		return (error);
 	return (uart_bus_attach(dev));
Index: sys/dev/uart/uart_bus_pci.c
===================================================================
--- sys/dev/uart/uart_bus_pci.c
+++ sys/dev/uart/uart_bus_pci.c
@@ -201,7 +201,7 @@
 	return (ENXIO);
 
  match:
-	result = uart_bus_probe(dev, id->regshft, id->rclk, id->rid, 0);
+	result = uart_bus_probe(dev, id->regshft, 0, id->rclk, id->rid, 0);
 	/* Bail out on error. */
 	if (result > 0)
 		return (result);
Index: sys/dev/uart/uart_bus_puc.c
===================================================================
--- sys/dev/uart/uart_bus_puc.c
+++ sys/dev/uart/uart_bus_puc.c
@@ -81,7 +81,7 @@
 
 	if (BUS_READ_IVAR(parent, dev, PUC_IVAR_CLOCK, &rclk))
 		rclk = 0;
-	return (uart_bus_probe(dev, 0, rclk, 0, 0));
+	return (uart_bus_probe(dev, 0, 0, rclk, 0, 0));
 }
 
 DRIVER_MODULE(uart, puc, uart_puc_driver, uart_devclass, 0, 0);
Index: sys/dev/uart/uart_bus_scc.c
===================================================================
--- sys/dev/uart/uart_bus_scc.c
+++ sys/dev/uart/uart_bus_scc.c
@@ -112,7 +112,7 @@
 	    BUS_READ_IVAR(parent, dev, SCC_IVAR_REGSHFT, &rs))
 		return (ENXIO);
 
-	return (uart_bus_probe(dev, rs, cl, 0, ch));
+	return (uart_bus_probe(dev, rs, 0, cl, 0, ch));
 }
 
 DRIVER_MODULE(uart, scc, uart_scc_driver, uart_devclass, 0, 0);
Index: sys/dev/uart/uart_core.c
===================================================================
--- sys/dev/uart/uart_core.c
+++ sys/dev/uart/uart_core.c
@@ -256,6 +256,12 @@
 	return ((uc != NULL) ? uc->uc_rshift : 0);
 }
 
+u_int
+uart_getregiowidth(struct uart_class *uc)
+{
+	return ((uc != NULL) ? uc->uc_riowidth : 0);
+}
+
 /*
  * Schedule a soft interrupt. We do this on the 0 to !0 transition
  * of the TTY pending interrupt status.
@@ -485,7 +491,7 @@
 }
 
 int
-uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan)
+uart_bus_probe(device_t dev, int regshft, int regiowidth, int rclk, int rid, int chan)
 {
 	struct uart_softc *sc;
 	struct uart_devinfo *sysdev;
@@ -543,6 +549,7 @@
 	sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
 	sc->sc_bas.chan = chan;
 	sc->sc_bas.regshft = regshft;
+	sc->sc_bas.regiowidth = regiowidth;
 	sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
 
 	SLIST_FOREACH(sysdev, &uart_sysdevs, next) {
Index: sys/dev/uart/uart_cpu.h
===================================================================
--- sys/dev/uart/uart_cpu.h
+++ sys/dev/uart/uart_cpu.h
@@ -80,6 +80,7 @@
 struct uart_ops *uart_getops(struct uart_class *);
 int uart_getrange(struct uart_class *);
 u_int uart_getregshift(struct uart_class *);
+u_int uart_getregiowidth(struct uart_class *);
 
 void uart_add_sysdev(struct uart_devinfo *);
 
Index: sys/dev/uart/uart_cpu_arm64.c
===================================================================
--- sys/dev/uart/uart_cpu_arm64.c
+++ sys/dev/uart/uart_cpu_arm64.c
@@ -155,7 +155,7 @@
 	struct uart_class *class;
 	bus_space_handle_t bsh;
 	bus_space_tag_t bst;
-	u_int rclk, shift;
+	u_int rclk, shift, iowidth;
 	int br, err;
 
 	/* Allow overriding the FDT using the environment. */
@@ -174,7 +174,7 @@
 #ifdef FDT
 	if (err != 0) {
 		err = uart_cpu_fdt_probe(&class, &bst, &bsh, &br, &rclk,
-		    &shift);
+		    &shift, &iowidth);
 	}
 #endif
 	if (err != 0)
@@ -185,6 +185,7 @@
 	 */
 	di->bas.chan = 0;
 	di->bas.regshft = shift;
+	di->bas.regiowidth = iowidth;
 	di->baudrate = br;
 	di->bas.rclk = rclk;
 	di->ops = uart_getops(class);
Index: sys/dev/uart/uart_cpu_fdt.h
===================================================================
--- sys/dev/uart/uart_cpu_fdt.h
+++ sys/dev/uart/uart_cpu_fdt.h
@@ -51,8 +51,9 @@
 	DATA_SET(uart_fdt_class_set, data)
 
 int uart_cpu_fdt_probe(struct uart_class **, bus_space_tag_t *,
-    bus_space_handle_t *, int *, u_int *, u_int *);
+    bus_space_handle_t *, int *, u_int *, u_int *, u_int *);
 int uart_fdt_get_clock(phandle_t node, pcell_t *cell);
 int uart_fdt_get_shift(phandle_t node, pcell_t *cell);
+int uart_fdt_get_io_width(phandle_t node, pcell_t *cell);
 
 #endif /* _DEV_UART_CPU_FDT_H_ */
Index: sys/dev/uart/uart_cpu_fdt.c
===================================================================
--- sys/dev/uart/uart_cpu_fdt.c
+++ sys/dev/uart/uart_cpu_fdt.c
@@ -76,7 +76,7 @@
 	struct uart_class *class;
 	bus_space_tag_t bst;
 	bus_space_handle_t bsh;
-	u_int shift, rclk;
+	u_int shift, iowidth, rclk;
 	int br, err;
 
 	/* Allow overriding the FDT using the environment. */
@@ -88,7 +88,7 @@
 	if (devtype != UART_DEV_CONSOLE)
 		return (ENXIO);
 
-	err = uart_cpu_fdt_probe(&class, &bst, &bsh, &br, &rclk, &shift);
+	err = uart_cpu_fdt_probe(&class, &bst, &bsh, &br, &rclk, &shift, &iowidth);
 	if (err != 0)
 		return (err);
 
@@ -97,6 +97,7 @@
 	 */
 	di->bas.chan = 0;
 	di->bas.regshft = shift;
+	di->bas.regiowidth = iowidth;
 	di->baudrate = br;
 	di->bas.rclk = rclk;
 	di->ops = uart_getops(class);
Index: sys/dev/uart/uart_dev_snps.c
===================================================================
--- sys/dev/uart/uart_dev_snps.c
+++ sys/dev/uart/uart_dev_snps.c
@@ -136,7 +136,7 @@
 	struct snps_softc *sc;
 	struct uart_class *uart_class;
 	phandle_t node;
-	uint32_t shift, clock;
+	uint32_t shift, iowidth, clock;
 	uint64_t freq;
 	int error;
 #ifdef EXT_RESOURCES
@@ -159,6 +159,8 @@
 	node = ofw_bus_get_node(dev);
 	if (OF_getencprop(node, "reg-shift", &shift, sizeof(shift)) <= 0)
 		shift = 0;
+	if (OF_getencprop(node, "reg-io-width", &iowidth, sizeof(iowidth)) <= 0)
+		iowidth = 1;
 	if (OF_getencprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
 		clock = 0;
 
@@ -200,7 +202,7 @@
 	if (bootverbose && clock == 0)
 		device_printf(dev, "could not determine frequency\n");
 
-	error = uart_bus_probe(dev, (int)shift, (int)clock, 0, 0);
+	error = uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0);
 	if (error != 0)
 		return (error);
 
Index: sys/mips/adm5120/uart_bus_adm5120.c
===================================================================
--- sys/mips/adm5120/uart_bus_adm5120.c
+++ sys/mips/adm5120/uart_bus_adm5120.c
@@ -87,7 +87,7 @@
 	sc->sc_class = &uart_adm5120_uart_class;
 	bcopy(&sc->sc_sysdev->bas, &sc->sc_bas, sizeof(sc->sc_bas));
 
-	return (uart_bus_probe(dev, 0, 0, 0, 0));
+	return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 }
 
 DRIVER_MODULE(uart, obio, uart_adm5120_driver, uart_devclass, 0, 0);
Index: sys/mips/alchemy/uart_bus_alchemy.c
===================================================================
--- sys/mips/alchemy/uart_bus_alchemy.c
+++ sys/mips/alchemy/uart_bus_alchemy.c
@@ -81,7 +81,7 @@
 	sc->sc_class = &uart_ns8250_class;
 	bcopy(&sc->sc_sysdev->bas, &sc->sc_bas, sizeof(sc->sc_bas));
 
-	return (uart_bus_probe(dev, 0, 0, 0, 0));
+	return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 }
 
 DRIVER_MODULE(uart, obio, uart_alchemy_driver, uart_devclass, 0, 0);
Index: sys/mips/atheros/ar531x/uart_bus_ar5315.c
===================================================================
--- sys/mips/atheros/ar531x/uart_bus_ar5315.c
+++ sys/mips/atheros/ar531x/uart_bus_ar5315.c
@@ -83,7 +83,7 @@
 	sc->sc_bas.bst = mips_bus_space_generic;
 	sc->sc_bas.bsh = ar531x_uart_addr() + 3;
 
-	return (uart_bus_probe(dev, 2, freq, 0, 0));
+	return (uart_bus_probe(dev, 2, 0, freq, 0, 0));
 }
 
 DRIVER_MODULE(uart, apb, uart_ar5315_driver, uart_devclass, 0, 0);
Index: sys/mips/atheros/uart_bus_ar71xx.c
===================================================================
--- sys/mips/atheros/uart_bus_ar71xx.c
+++ sys/mips/atheros/uart_bus_ar71xx.c
@@ -83,7 +83,7 @@
 	sc->sc_bas.bst = mips_bus_space_generic;
 	sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(AR71XX_UART_ADDR) + 3;
 
-	return (uart_bus_probe(dev, 2, freq, 0, 0));
+	return (uart_bus_probe(dev, 2, 0, freq, 0, 0));
 }
 
 #ifdef	EARLY_PRINTF
Index: sys/mips/atheros/uart_bus_ar933x.c
===================================================================
--- sys/mips/atheros/uart_bus_ar933x.c
+++ sys/mips/atheros/uart_bus_ar933x.c
@@ -88,7 +88,7 @@
 	sc->sc_bas.bst = mips_bus_space_generic;
 	sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(AR71XX_UART_ADDR);
 
-	return (uart_bus_probe(dev, 2, freq, 0, 0));
+	return (uart_bus_probe(dev, 2, 0, freq, 0, 0));
 }
 
 /*
Index: sys/mips/broadcom/uart_bus_chipc.c
===================================================================
--- sys/mips/broadcom/uart_bus_chipc.c
+++ sys/mips/broadcom/uart_bus_chipc.c
@@ -61,7 +61,7 @@
 	sc->sc_class = &uart_ns8250_class;
 
 	rclk = bcm_get_uart_rclk(bcm_get_platform());
-	return (uart_bus_probe(dev, 0, rclk, 0, 0));
+	return (uart_bus_probe(dev, 0, 0, rclk, 0, 0));
 }
 
 static device_method_t uart_chipc_methods[] = {
Index: sys/mips/cavium/uart_bus_octeonusart.c
===================================================================
--- sys/mips/cavium/uart_bus_octeonusart.c
+++ sys/mips/cavium/uart_bus_octeonusart.c
@@ -105,7 +105,7 @@
 	if (bus_space_map(sc->sc_bas.bst, CVMX_MIO_UARTX_RBR(0),
 	    uart_getrange(sc->sc_class), 0, &sc->sc_bas.bsh) != 0)
 		return (ENXIO);
-	return (uart_bus_probe(dev, sc->sc_bas.regshft, 0, 0, unit));
+	return (uart_bus_probe(dev, sc->sc_bas.regshft, 0, 0, 0, unit));
 }
 
 DRIVER_MODULE(uart, obio, uart_octeon_driver, uart_devclass, 0, 0);
Index: sys/mips/idt/uart_bus_rc32434.c
===================================================================
--- sys/mips/idt/uart_bus_rc32434.c
+++ sys/mips/idt/uart_bus_rc32434.c
@@ -94,7 +94,7 @@
 	sc->sc_bas.bst = mips_bus_space_generic;
 	sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(IDT_BASE_UART0);
 
-	return (uart_bus_probe(dev, 2, 330000000UL/2, 0, 0));
+	return (uart_bus_probe(dev, 2, 0, 330000000UL/2, 0, 0));
 }
 
 DRIVER_MODULE(uart, obio, uart_rc32434_driver, uart_devclass, 0, 0);
Index: sys/mips/ingenic/jz4780_uart.c
===================================================================
--- sys/mips/ingenic/jz4780_uart.c
+++ sys/mips/ingenic/jz4780_uart.c
@@ -179,7 +179,7 @@
 		device_printf(dev, "got UART clock: %lld\n", freq);
 	sc->ns8250_base.base.sc_class = (struct uart_class *)cd->ocd_data;
 	shift = jz4780_uart_get_shift(dev);
-	return (uart_bus_probe(dev, shift, (int)freq, 0, 0));
+	return (uart_bus_probe(dev, shift, 0, (int)freq, 0, 0));
 }
 
 static int
Index: sys/mips/malta/uart_bus_maltausart.c
===================================================================
--- sys/mips/malta/uart_bus_maltausart.c
+++ sys/mips/malta/uart_bus_maltausart.c
@@ -85,7 +85,7 @@
 	sc->sc_sysdev->bas.bsh = MIPS_PHYS_TO_KSEG1(MALTA_UART0ADR);
 	sc->sc_bas.bst = mips_bus_space_generic;
 	sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(MALTA_UART0ADR);
-	return(uart_bus_probe(dev, 0, 0, 0, 0));
+	return(uart_bus_probe(dev, 0, 0, 0, 0, 0));
 }
 
 DRIVER_MODULE(uart, obio, uart_malta_driver, uart_devclass, 0, 0);
Index: sys/mips/rmi/uart_bus_xlr_iodi.c
===================================================================
--- sys/mips/rmi/uart_bus_xlr_iodi.c
+++ sys/mips/rmi/uart_bus_xlr_iodi.c
@@ -74,7 +74,7 @@
 	sc->sc_bas.bst = rmi_bus_space;
 	sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(XLR_UART0ADDR);
 	/* regshft = 2, rclk = 66000000, rid = 0, chan = 0 */
-	return (uart_bus_probe(dev, 2, 66000000, 0, 0));
+	return (uart_bus_probe(dev, 2, 0, 66000000, 0, 0));
 }
 
 DRIVER_MODULE(uart, iodi, uart_iodi_driver, uart_devclass, 0, 0);
Index: sys/mips/rt305x/uart_bus_rt305x.c
===================================================================
--- sys/mips/rt305x/uart_bus_rt305x.c
+++ sys/mips/rt305x/uart_bus_rt305x.c
@@ -87,7 +87,7 @@
 	sc->sc_bas.bsh = 
 	    MIPS_PHYS_TO_KSEG1(device_get_unit(dev)?UARTLITE_BASE:UART_BASE);
 
-	return (uart_bus_probe(dev, 2, SYSTEM_CLOCK, 0, 0));
+	return (uart_bus_probe(dev, 2, 0, SYSTEM_CLOCK, 0, 0));
 }
 
 DRIVER_MODULE(uart, obio, uart_rt305x_driver, uart_devclass, 0, 0);
Index: sys/powerpc/psim/uart_iobus.c
===================================================================
--- sys/powerpc/psim/uart_iobus.c
+++ sys/powerpc/psim/uart_iobus.c
@@ -81,7 +81,7 @@
 	sc->sc_class = &uart_ns8250_class;
 
 	device_set_desc(dev, "PSIM serial port");
-	return (uart_bus_probe(dev, 0, 0, 0, 0));
+	return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 }
 
 DRIVER_MODULE(uart, iobus, uart_iobus_driver, uart_devclass, 0, 0);
Index: sys/sparc64/pci/sbbc.c
===================================================================
--- sys/sparc64/pci/sbbc.c
+++ sys/sparc64/pci/sbbc.c
@@ -618,7 +618,7 @@
 	sc = device_get_softc(dev);
 	sc->sc_class = &uart_sbbc_class;
 	device_set_desc(dev, "Serengeti console");
-	return (uart_bus_probe(dev, 0, 0, SBBC_PCI_BAR, 0));
+	return (uart_bus_probe(dev, 0, 0, 0, SBBC_PCI_BAR, 0));
 }
 
 /*