Re: [PATCH v1 02/15] Documentation: ABI: add wideband filter type to sysfs-bus-iio

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 11 Jan 2025 19:50:18 -0300
Jonathan Santos <jonath4nns@gmail.com> wrote:

> On 01/07, David Lechner wrote:
> > On 1/7/25 9:24 AM, Jonathan Santos wrote:  
> > > The Wideband Low Ripple FIR filter is used for AD7768-1 Driver.
> > > Document wideband filter option into filter_type_avaialable  
> > 
> > s/avaialable/available/
> >   
> > > attribute.
> > > 
> > > Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
> > > ---
> > >  Documentation/ABI/testing/sysfs-bus-iio | 2 ++
> > >  1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> > > index f83bd6829285..c4c21a7bfba1 100644
> > > --- a/Documentation/ABI/testing/sysfs-bus-iio
> > > +++ b/Documentation/ABI/testing/sysfs-bus-iio
> > > @@ -2291,6 +2291,8 @@ Description:
> > >  		* "sinc3+pf2" - Sinc3 + device specific Post Filter 2.
> > >  		* "sinc3+pf3" - Sinc3 + device specific Post Filter 3.
> > >  		* "sinc3+pf4" - Sinc3 + device specific Post Filter 4.
> > > +		* "wideband" - FIR filter with wideband low ripple passband  
> > 
> > I think "fir" would be a more specific filter type name than "wideband". (i.e.
> > there are wikipedia pages for sinc and FIR filters, but not one for "wideband"
> > filters)
> >   
> 
> Isn't "fir" a bit too generic for this case? Since Wideband here is a class of a FIR filter.
> Maybe something like "wideband-fir" or "fir-wideband" would work better?


Not sure FIR is even useful. That's just a particular filter architecture, not
related directly to the characteristics userspace cares about.
You can sometimes at least build a very similar response from an IIR filter.
The sinc ones describe the pattern they let through, FIR isn't that specific.
So I'd not mention FIR anywhere.

> 
> > > +		  and sharp transition band.
> > >  
> > >  What:		/sys/.../events/in_proximity_thresh_either_runningperiod
> > >  KernelVersion:	6.6  
> >