Re: [PATCH v2 05/16] Documentation: ABI: add wideband filter type to sysfs-bus-iio
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Date: 2025-01-30 16:29:13
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On Mon, 27 Jan 2025 19:32:45 -0600 David Lechner [off-list ref] wrote:
On 1/27/25 9:12 AM, Jonathan Santos wrote:quoted
The Wideband Low Ripple filter is used for AD7768-1 Driver. Document wideband filter option into filter_type_available attribute. Signed-off-by: Jonathan Santos <redacted> --- v2 Changes: * Removed FIR mentions. --- 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..9b879e7732cd 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" - filter with wideband low ripple passband + and sharp transition band. What: /sys/.../events/in_proximity_thresh_either_runningperiod KernelVersion: 6.6I'm a bit shy to make any more suggestions on this one since my previous suggestions were clearly not the "right way". :-) But, the key takeaway I got from the discussion on v1 is that this describes the _shape_ of the filter. To me, "wideband" describes the size but not the shape. Would rectangular be the correct shape?
It's tricky. The filter definition is really vague! No filter is ever rectangular. Also, I've just noticed. This one is fully programable. It could be anything! I kind of hope no one cares about that feature as it looks really tricky to support. Wideband normally means 'flattish to a wide range of frequencies'. Not sure how best to convey that.