Re: [PATCH v5 1/6] dt-bindings: iio: filter: Add lpf/hpf freq margins

Krzysztof Kozlowski
2025-03-09T19:55:46Z

On 07/03/2025 14:47, Sam Winchenbach wrote:
> On Fri, Mar 07, 2025 at 09:34:24AM +0100, Krzysztof Kozlowski wrote:
>> On Thu, Mar 06, 2025 at 01:33:09PM -0500, Sam Winchenbach wrote:
>>> Adds two properties to add a margin when automatically finding the
>>> corner frequencies.
>>>
>>> Signed-off-by: Sam Winchenbach <sam.winchenbach@framepointer.org>
>>> ---
>>> .../bindings/iio/filter/adi,admv8818.yaml | 23 +++++++++++++++++++
>>> 1 file changed, 23 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/filter/adi,admv8818.yaml b/Documentation/devicetree/bindings/iio/filter/adi,admv8818.yaml
>>> index b77e855bd594..3f9c61547a78 100644
>>> --- a/Documentation/devicetree/bindings/iio/filter/adi,admv8818.yaml
>>> +++ b/Documentation/devicetree/bindings/iio/filter/adi,admv8818.yaml
>>> @@ -44,6 +44,27 @@ properties:
>>> '#clock-cells':
>>> const: 0
>>>
>>> +
>>
>> Unnecessary blank line
>>
>
> Noted for v6.
>
>>> + adi,lpf-margin-hz:
>>> + description:
>>> + Sets the minimum distance (in Hz) between the fundamental
>>> + frequency of `rf_in` and the corner frequency of the low-pass, output
>>> + filter when operatred in 'auto' mode. The selected low-pass corner
>>> + frequency will be greater than, or equal to, `rf_in` + `lpf-margin-hz`. If
>>> + not setting is found that satisfies this relationship the filter will be
>>> + put into 'bypass'.
>>> + default: 0
>>
>> hz are 32-bit, not 64-bit, so I think you need:
>>
>> default: [0, 0]
>> minItems: 2
>> maxItems: 2
>>
>
> I think I finally understand - "-hz" is a schema type defined as a uint32.

No, it is uint32-array.

> Is that correct? I am really surprised that `dt_binding_check` did not complain about it being 64-bits. I will update these to `-mhz` and make them uint32 in v6.

so your code worked fine, because it assumed you will pass two 32-bit
integers, so two items. That's why I proposed to define the number of
items, even though it looks odd, but that's result of 32-bit value.

Maybe we need "-hz-64" or "-64-hz" property suffix?

Best regards,
Krzysztof