sdmmc_chip_bus_power
error = sdmmc_chip_bus_power(sc->sc_sct, sc->sc_sch,
(void)sdmmc_chip_bus_power(sc->sc_sct, sc->sc_sch, 0);
sdmmc_chip_bus_power(sc->sc_sct, sc->sc_sch, host_ocr) != 0)