TPM_ID
id[i] = tpm_legacy_in(sc->sc_bt, sc->sc_bh, TPM_ID + i);
bus_space_read_4(bt, bh, TPM_ID) != 0xffffffff)
sc->sc_devid = bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_ID);
id[i] = tpm_legacy_in(iot, ioh, TPM_ID + i);