devm_spi_new_ancillary_device
st->spi[ch] = devm_spi_new_ancillary_device(spi, spi_get_chipselect(spi, ch));
EXPORT_SYMBOL_GPL(devm_spi_new_ancillary_device);
extern struct spi_device *devm_spi_new_ancillary_device(struct spi_device *spi, u8 chip_select);