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

On 1/12/25 11:39 AM, David Lechner wrote:

On 1/11/25 4:50 PM, Jonathan Santos wrote:

quoted

On 01/07, David Lechner wrote:

quoted

On 1/7/25 9:24 AM, Jonathan Santos wrote:

quoted

The Wideband Low Ripple FIR filter is used for AD7768-1 Driver.
Document wideband filter option into filter_type_avaialable

s/avaialable/available/

quoted

attribute.

Signed-off-by: Jonathan Santos <redacted>
---
 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?

For this particular chip, no, there is only one FIR filter option on the chip,
so having additional qualifiers doesn't really make a difference.

If we can find a chip that has more than one FIR filter option, then we could
use that to figure out what additional classifiers are might make sense.
"fir-wideband" would only be useful if the same chip also had a "fir-narrowband"
option. But we might find that instead the chip is actually "fir-type1"
"fir-type2" or something like that.

(FWIW, my signal processing textbook describes Type I, II, III, IV FIR filters
but doesn't say anything about "wideband" FIR filters.)

Oops, didn't read Jonathan's response first, so disregard this comment.