Re: [PATCH 1/1] arm64: dts: meson-g12b-odroid-n2: move assigned-clocks

[Jerome Brunet <jbrunet@baylibre.com>]

On Sun 19 Dec 2021 at 10:56, Alexander Stein <alexander.stein@mailbox.org> wrote:

> Am Samstag, 18. Dezember 2021, 16:03:16 CET schrieb Jerome Brunet:
>> 
>> On Sat 18 Dec 2021 at 15:26, Alexander Stein <alexander.stein@mailbox.org> wrote:
>> 
>> > dtschema expects a 'clocks' property if 'assigned-clocks' is used, but
>> > 'sound' node does not.
>> > So move the MPLL[0-2] clock settings &clkc_audio which actually use them.
>> 
>> No, this does not make sense.
>> The sound card needs the clocks set in such way - nothing else
>> The clock controller work just as well regarless of the clock rate
>> 
>> Having a clock property or not does not change that

Also the documentation of assigned does not mandate that.

>
> Well, I checked what others did to fix this warning. So I did the same as in [1].
> Despite that, IMHO if you split 'assigned-clocks' for the same clock ´all
> over users who is gonna win?

1. This is explicitly forbidden by the assigned-clock binding documentation
2. Like other interfaces, it is likely a last write wins

The fact the ID assigned by the card and the one claimed controller are
the same is merely a coincidence. The ID assigned could very well have
been internal to the audio controller.

> Because the sound card needs the clocks set
> his way it is set, it is done in the same file.

If I push this logic further, I may as well put everything at root of DT,
or anywhere else, as long as it is in the same file and there is a clock
property for the schema. We could put it with uart, that would work ;)
(just kidding)

The cards needs these rate because of rate family we choose to support,
and how we choose to support them. This is where the assignment makes
sense.

>
> Best regards,
> Alexander
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4afb06afd76855932a2d19c983c013105f1cfb9a
>
>> > This fixes the dtschema warning:
>> > arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dt.yaml: sound: 'clocks' is a dependency of 'assigned-clocks'
>> >
>> 
>> Then the schema needs fixing IMO
>> 
>> > Signed-off-by: Alexander Stein <alexander.stein@mailbox.org>
>> > ---
>> >  .../boot/dts/amlogic/meson-g12b-odroid-n2.dtsi    | 15 +++++++--------
>> >  1 file changed, 7 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi
>> > index 9c05c83453f5..85257507206c 100644
>> > --- a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi
>> > +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dtsi
>> > @@ -252,14 +252,6 @@ sound {
>> >  				"U19 INR", "ACODEC LORP",
>> >  				"Lineout", "U19 OUTL",
>> >  				"Lineout", "U19 OUTR";
>> > -
>> > -		assigned-clocks = <&clkc CLKID_MPLL2>,
>> > -				  <&clkc CLKID_MPLL0>,
>> > -				  <&clkc CLKID_MPLL1>;
>> > -		assigned-clock-parents = <0>, <0>, <0>;
>> > -		assigned-clock-rates = <294912000>,
>> > -				       <270950400>,
>> > -				       <393216000>;
>> >  		status = "okay";
>> >  
>> >  		dai-link-0 {
>> > @@ -365,6 +357,13 @@ &cecb_AO {
>> >  };
>> >  
>> >  &clkc_audio {
>> > +	assigned-clocks = <&clkc CLKID_MPLL2>,
>> > +				<&clkc CLKID_MPLL0>,
>> > +				<&clkc CLKID_MPLL1>;
>> > +	assigned-clock-parents = <0>, <0>, <0>;
>> > +	assigned-clock-rates = <294912000>,
>> > +					<270950400>,
>> > +					<393216000>;
>> >  	status = "okay";
>> >  };
>> 
>>