spi_new_ancillary_device
achc->ezport = spi_new_ancillary_device(spi, ezport_reg);
EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
ancillary = spi_new_ancillary_device(spi, chip_select);
extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select);