Index: sys/mips/atheros/ar71xx_gpio.c
===================================================================
--- sys/mips/atheros/ar71xx_gpio.c
+++ sys/mips/atheros/ar71xx_gpio.c
@@ -581,6 +581,30 @@
 		ar71xx_gpio_ouput_configure(i, gpiofunc);
 	}
 
+	for (i = 0; i <= maxpin; i++) {
+		char buf[32];
+		int gpiomux;
+		int muxoff, muxbit, outfunc;
+
+		snprintf(buf, 32, "func.%d.outmux", i);
+		if (resource_int_value(device_get_name(dev),
+		    device_get_unit(dev),
+		    buf,
+		    &gpiomux) != 0)
+			continue;
+
+		device_printf(dev, "GPIO %d: mux=%d\n",
+		    i,
+		    gpiomux);
+
+		muxoff = (i / 4) * 4;
+		muxbit = (i % 4) * 8;
+		outfunc = GPIO_READ(sc, AR71XX_GPIO_OUT_FUNCTION + muxoff);
+		outfunc &= ~ (0xff < muxbit);
+		outfunc |= gpiomux << muxbit;
+		GPIO_WRITE(sc, AR71XX_GPIO_OUT_FUNCTION + muxoff, outfunc);
+	}
+
 	sc->busdev = gpiobus_attach_bus(dev);
 	if (sc->busdev == NULL) {
 		ar71xx_gpio_detach(dev);
Index: sys/mips/atheros/ar71xxreg.h
===================================================================
--- sys/mips/atheros/ar71xxreg.h
+++ sys/mips/atheros/ar71xxreg.h
@@ -164,6 +164,7 @@
 #define			GPIO_FUNC_UART_EN       (1 << 8)
 #define			GPIO_FUNC_USB_OC_EN     (1 << 4)
 #define			GPIO_FUNC_USB_CLK_EN    (0)
+#define		AR71XX_GPIO_OUT_FUNCTION	0x2c
 
 #define	AR71XX_BASE_FREQ		40000000
 #define	AR71XX_PLL_CPU_BASE		0x18050000