ad9467_spi_read
id = ad9467_spi_read(st, AN877_ADC_REG_CHIP_ID);
ret = ad9467_spi_read(st, reg);
ret = ad9467_spi_read(st, AN877_ADC_REG_VREF);
ret = ad9467_spi_read(st, AN877_ADC_REG_OFFSET);