Re: [PATCH v3] dt-bindings: iio: adc: Convert xilinx-xadc bindings to YAML schema

[David Lechner <dlechner@baylibre.com>]

On 5/12/26 8:58 AM, David Lechner wrote:
> On 5/12/26 7:14 AM, Rob Herring wrote:
>> On Mon, May 11, 2026 at 11:24 AM David Lechner <dlechner@baylibre.com> wrote:
>>>
>>> On 5/11/26 11:15 AM, Jonathan Cameron wrote:
>>>> On Sun, 10 May 2026 08:01:36 -0400
>>>> Pramod Maurya <pramod.nexgen@gmail.com> wrote:
>>>>
>>>>> Convert the Xilinx XADC and UltraScale System Monitor device tree binding
>>>>> from the legacy plain-text format to a YAML schema, enabling automated
>>>>> validation with dt-schema.
>>>>>
>>>>> The new binding covers the same hardware and compatible strings:
>>>>>   - xlnx,zynq-xadc-1.00.a (ZYNQ hardmacro)
>>>>>   - xlnx,axi-xadc-1.00.a  (AXI softmacro)
>>>>>   - xlnx,system-management-wiz-1.3 (UltraScale System Management Wizard)
>>>>>
>>>>> Signed-off-by: Pramod Maurya <pramod.nexgen@gmail.com>
>>>> Hi Pramod,
>>>>
>>>> Something went wrong with your sending of v3. I have two versions sent
>>>> half a day apart and no idea how they are related.
>>>>
>>>> Anyhow one of them got feedback from Rob's bot so I'll assume we are
>>>> getting a v4 and wait for that.
>>>>
>>>> Jonathan
>>>
>>> I think Rob will have to fix the bot to make an exception for the
>>> legacy bindings. This should have been called out in the commit message
>>> as requested in a previous revision.
>>
>> The bot is not the problem. It just runs validation. The schemas will
>> have to either drop this check (comma's in nodenames) or exclude just
>> this property.
>>
>>
>> Rob
> 
> Even though this is an existing text-based schema that has been around
> for 12 years with this name already? Changing it could be a breaking
> change to existing users. Although there aren't any in any .dts in the
> kernel source.

Pramod,

Unless Rob changes his mind, the thing to do would be to use the standard
channels property from adc.yaml when converting the binding instead of
xlnx,channels.

We will also need to add handling in the driver for "channels" while
preserving "xlnx,channels" handling for backwards compatibility.

xlnx,channels will just be undocumented.

And all of this reasoning must be explained in the commit messages.