On 20/04/2024 18:15, Jan Dakinevich wrote:
>
>
> On 4/20/24 00:09, Rob Herring wrote:
>> On Fri, Apr 19, 2024 at 03:58:10PM +0300, Jan Dakinevich wrote:
>>> Add device tree bindings for A1 SoC audio clock and reset controllers.
>>>
>>> Signed-off-by: Jan Dakinevich <jan.dakinevich@xxxxxxxxxxxxxxxxx>
>>> ---
>>>
>>> This controller has 6 mandatory and up to 20 optional clocks. To describe
>>> this, I use 'additionalItems'. It produces correct processed-schema.json:
>>>
>>> "clock-names": {
>>> "maxItems": 26,
>>> "items": [
>>> {
>>> "const": "pclk"
>>> },
>>> {
>>> "const": "dds_in"
>>> },
>>> {
>>> "const": "fclk_div2"
>>> },
>>> {
>>> "const": "fclk_div3"
>>> },
>>> {
>>> "const": "hifi_pll"
>>> },
>>> {
>>> "const": "xtal"
>>> }
>>> ],
>>> "additionalItems": {
>>> "oneOf": [
>>> {
>>> "pattern": "^slv_sclk[0-9]$"
>>> },
>>> {
>>> "pattern": "^slv_lrclk[0-9]$"
>>> }
>>> ]
>>> },
>>> "type": "array",
>>> "minItems": 6
>>> },
>>>
>>> and it behaves as expected. However, the checking is followed by
>>> complaints like this:
>>>
>>> Documentation/devicetree/bindings/clock/amlogic,a1-audio-clkc.yaml: properties:clock-names:additionalItems: {'oneOf': [{'pattern': '^slv_sclk[0-9]$'}, {'pattern': '^slv_lrclk[0-9]$'}]} is not of type 'boolean'
>>>
>>> And indeed, 'additionalItems' has boolean type in meta-schema. So, how to
>>> do it right?
>>
>> The meta-schemas are written both to prevent nonsense that json-schema
>> allows by default (e.g additionalitems (wrong case)) and constraints to
>> follow the patterns we expect. I'm happy to loosen the latter case if
>> there's really a need.
>>
>> Generally, most bindings shouldn't be using 'additionalItems' at all as
>> all entries should be defined, but there's a few exceptions. Here, the
>> only reasoning I see is 26 entries is a lot to write out, but that
>> wouldn't really justify it.
>
> Writing a lot of entries don't scary me too much, but the reason is that
> the existence of optional clock sources depends on schematics. Also, we
Aren't you documenting SoC component, not a board? So how exactly it
depends on schematics? SoC is done or not done...
> unable to declare dt-nodes for 'clocks' array in any generic way,
> because their declaration would depends on that what is actually
> connected to the SoC (dt-node could be "fixed-clock" with specific rate
> or something else).
So these are clock inputs to the SoC?
>
> By the way, I don't know any example (neither for A1 SoC nor for other
> Amlogic's SoCs) where these optional clocks are used, but they are
> allowed by hw.
>
> This is my understanding of this controller. I hope, Jerome Brunet will
> clarify how it actually works.
Best regards,
Krzysztof
