IIO_CONCENTRATION channel for the DO-SM shouldn't be indexed as there isn't more than one, and also ATLAS_CONCENTRATION_CHANNEL macro scan_index define steps on the IIO_TIMESTAMP channel. Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com> Fixes: a751b8e48018 (iio: chemical: atlas-sensor: add DO-SM module support) Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>