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Date: Sun, 6 Apr 2025 12:21:51 +0100
From: Jonathan Cameron <jic23@kernel.org>
To: gyeyoung <gye976@gmail.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>,
 linux-iio@vger.kernel.org, devicetree@vger.kernel.org, lars@metafoo.de,
 gustavograzs@gmail.com, javier.carrasco.cruz@gmail.com, robh@kernel.org,
 krzk+dt@kernel.org, conor+dt@kernel.org
Subject: Re: [PATCH v1 4/5] iio: chemical: add support for winsen MHZ19B CO2
 sensor
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	<20250403053225.298308-5-gye976@gmail.com>
	<20250404125155.0000738d@huawei.com>
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> > > +
> > > +static const struct iio_chan_spec mhz19b_channels[] = {
> > > +     {
> > > +             .type = IIO_CONCENTRATION,
> > > +             .channel2 = IIO_MOD_CO2,
> > > +             .modified = 1,
> > > +             .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),  
> >
> > I'm curious. We have a range control in your custom ABI, but no scale.
> > So what units is this in?
> >  
> The unit is ppm. and as far as I understand, co2 input(processed) unit
>  is percentage concentration.
> so In this device, the scale is a constant value (0.0001), regardless
> of the range.
> Is my understanding correct?

Yes.