mpf_spi_write
ret = mpf_spi_write(priv, txbuf, txbuf_size);
ret = mpf_spi_write(priv, program_mode, sizeof(program_mode));
ret = mpf_spi_write(priv, isc_dis_command, sizeof(isc_dis_command));
ret = mpf_spi_write(priv, release_command, sizeof(release_command));