Re: [PATCH v11 03/13] dt-bindings: Convert gpio-mmio to yaml

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 14/03/2023 20:52, Sean Anderson wrote:
> On 3/14/23 15:45, Krzysztof Kozlowski wrote:
>> On 14/03/2023 19:50, Sean Anderson wrote:
>>> On 3/14/23 14:32, Krzysztof Kozlowski wrote:
>>>> On 14/03/2023 19:09, Sean Anderson wrote:
>>>>> On 3/14/23 13:56, Krzysztof Kozlowski wrote:
>>>>>> On 13/03/2023 17:11, Sean Anderson wrote:
>>>>>> +  reg-names:
>>>>>>> +    minItems: 1
>>>>>>> +    maxItems: 5
>>>>>>> +    items:
>>>>>>> +      enum:
>>>>>>
>>>>>> Why this is in any order? Other bindings were here specific, your 'reg'
>>>>>> is also specific/fixed.
>>>>>
>>>>> Some devicetrees have dirout first, and other have dat first. There is no
>>>>> mandatory order, and some registers can be included or left out as is
>>>>> convenient to the devicetree author.
>>>>>
>>>>> reg is not specific/fixed either. It is just done that way for
>>>>> convenience (and to match the names here).
>>>>
>>>> The items have order and usually we require strict order from DTS,
>>>> unless there is a reason. If there is no reason, use fixed order and
>>>> then fix the DTS.
>>>
>>> The items do not have order. That is the whole point of having a
>>> separate names property. The DTs are not "broken" for taking advantage
>>> of a longstanding feature. There is no advantage to rewriting them to
>>> use a fixed order, especially when there is no precedent. This is just
>>> an area where json schema cannot completely validate devicetrees.
>>
>> I don't understand "there is no precedent".There is - we rewrite
>> hundreds of DTS. Just look at mine and other people commits.
> 
> There is no precedent for a fixed order of registers for this device.
> We have always used reg-names to interpret regs.

And who is "we"? Bootloader? Firmware? BSD? Because they all matter. It
does not matter that one particular driver uses reg-names. The common
rule is always the same - entries are ordered and fixed (with exceptions).

> 
>> The reg-names are helper and entries were always expected to be ordered
> 
> This is not the case for this device. Registers may be in any order, and

Their physical order does not determine the order of entries in DT.

> some registers may be omitted (and not always the same ones).

OK, that's the reason.

> reg-names is the
> only way to determine which registers are present.


Best regards,
Krzysztof