bcm283x_pin_setfunc
void bcm283x_pin_setfunc(const struct bcmgpio_softc * const, u_int,
bcm283x_pin_setfunc(sc, pin, value);
bcm283x_pin_setfunc(sc, pin, BCM2835_GPIO_IN);
bcm283x_pin_setfunc(sc, pin, BCM2835_GPIO_OUT);
bcm283x_pin_setfunc(sc, pin, func);