Re: [PATCH 6/6] iio: mcp9600: Add support for IIR filter

From: Ben Collins
Date: Tue Aug 19 2025 - 10:16:55 EST


On Tue, Aug 19, 2025 at 09:05:39AM -0500, David Lechner wrote:
> On 8/18/25 1:32 PM, Ben Collins wrote:
> > From: Ben Collins <bcollins@xxxxxxxxxx>
> >
> > MCP9600 supports an IIR filter with 7 levels. Add IIR attribute
> > to allow get/set of this value.
> >
> > Use a filter_type[none, ema] for enabling the IIR filter.
> >
> > Signed-off-by: Ben Collins <bcollins@xxxxxxxxxx>
> > ---
> > + if (data->filter_level == 0)
> > + return -EINVAL;
>
> To implement Jonathan's request from v5, drop this error return.
> We'll also need a separate bool data->is_filter_enabled field so
> that we can keep the last set filter_level even when the filter
> is disabled. (i.e. data->filter_level is never == 0).
>
> This way, if you set the filter level, you can enable and disable
> the filter via filter_type and still have the same filter level.
>

Thanks, David. This is exactly what I've implemented, plus the
filter_enable attribute.

Adding the ABI doc updates as well.

--
Ben Collins
https://libjwt.io
https://github.com/benmcollins
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