gpio_pin_get_by_bus_pinnum
err = gpio_pin_get_by_bus_pinnum(busdev, pin, &ctx->gpio);
return (gpio_pin_get_by_bus_pinnum(device_get_parent(childdev),
int gpio_pin_get_by_bus_pinnum(device_t _bus, uint32_t _pinnum, gpio_pin_t *_gp);
err = gpio_pin_get_by_bus_pinnum(sc->sc_pdev, pin, &intr_conf->pin);