octmpi_reg_rd
data[i] = octmpi_reg_rd(sc, MPI_DAT2_OFFSET + i * 0x8);
tmp = octmpi_reg_rd(sc, MPI_STS_OFFSET);
tmp = octmpi_reg_rd(sc, MPI_STS_OFFSET);
static inline uint64_t octmpi_reg_rd(struct octmpi_softc *, int);