Re: [PATCH 1/2] arm64: dts: renesas: r9a07g044: Fix external clk node names

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

On 24/04/2022 12:22, Biju Das wrote:
> Hi Krzysztof Kozlowski,
> 
> Thanks for the feedback.
> 
>> Subject: Re: [PATCH 1/2] arm64: dts: renesas: r9a07g044: Fix external clk
>> node names
>>
>> On 24/04/2022 09:50, Biju Das wrote:
>>>> Subject: RE: [PATCH 1/2] arm64: dts: renesas: r9a07g044: Fix external
>>>> clk node names
>>>>
>>>> Hi Krzysztof Kozlowski,
>>>>
>>>> Thanks for the feedback.
>>>>
>>>>> Subject: Re: [PATCH 1/2] arm64: dts: renesas: r9a07g044: Fix
>>>>> external clk node names
>>>>>
>>>>> On 23/04/2022 16:06, Biju Das wrote:
>>>>>> Fix audio clk node names with "_" -> "-" and add suffix '-clk' for
>>>>>> can and extal clks.
>>>>>>
>>>>>> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
>>>>>> ---
>>>>>>  arch/arm64/boot/dts/renesas/r9a07g044.dtsi | 8 ++++----
>>>>>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
>>>>>> b/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
>>>>>> index 19287cccb1f0..4f9a84d7af08 100644
>>>>>> --- a/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
>>>>>> +++ b/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
>>>>>> @@ -13,14 +13,14 @@ / {
>>>>>>  	#address-cells = <2>;
>>>>>>  	#size-cells = <2>;
>>>>>>
>>>>>> -	audio_clk1: audio_clk1 {
>>>>>> +	audio_clk1: audio-clk1 {
>>>>>
>>>>> How about in such case keeping suffix "clk" everywhere and moving
>>>>> the index
>>>>> (1/2) to the first part? This way one day maybe schema will match
>>>>> the clocks.
>>>>
>>>> Just a question,
>>>>
>>>> Your suggestion is "audio_clk1: audio-clk1" -> "audio_clk1: audio-clk"
>>>>
>>>> In that case, If you plan to drop the label in future, how will you
>>>> differentiate between
>>>> audio-clk1 and audio-clk2 with just node names?
>>>
>>> Or
>>>
>>> Do you want me to do the change like this?
>>>
>>> "audio_clk1: audio-clk1" -> "audio_clk_1: audio-clk-1"
>>>
>>> And fix the phandle reference in other dtsi files??
>>
>> My suggestion was to move the [12] part into the first part, so the suffix
>> "clk" stays consistent:
>> audio1-clk
>> audio2-clk
> 
> From HW perspective,  there are 2 audio clocks, audio clock1(multiple and sub multiple of 44.1 Khz) 
> and audio clk 2(Multiple and submultiple of 48Khz) connected to a single audio Codec.
> 
> Based on the sampling rate, through clock generator driver we can switch the clock source for 
> audio mclock along with audio clock for SSI and we can support both these rates 
> 
> Since there is a single audio codec, I am not sure, audio1-clk and audio2-clk is a good choise.

The name of the clock is not "audio clock" but "audio", because you do
not call a car "Ford Mustang car", but just "Ford Mustang". Therefore
"clock" is not part of the name, but just description of a type.

> 
> What about like 
> 
> audio_clk1: audio-clk-1 ?
> audio_clk2: audio-clk-2 ?
> 
> Which is consistent with naming used for cpu and opp-tables?


It's not consistent with clk naming. Nodes should have generic names, so
the generic part is "clk". You add specific audio/audio-X prefix or
suffix - it's fine, but not both.

This is exactly the trouble when you start using specific names and
Devicetree spec explicitly asks for generic names. So maybe go with the
spec and call of these "clk-[0-9]" and problem is gone.


Best regards,
Krzysztof