On 25/10/2022 05:14, Aidan MacDonald wrote:
>> Krzysztof
>
> Device trees already use standardized enumerations in other areas so it
> isn't a new idea. Look under include/dt-bindings/clock. Every header
> there contains an arbitrary enumeration of a device's clocks. In fact
> most of include/dt-bindings is exactly for this purpose, to define
> standard values that are not "just numbers" but an enum, a flag, etc,
> with a special meaning. It is not specific to clocks.
>
> There is no dt-binding for system clock ID, because prior to this patch
> they were not exposed to DT in any way. But the enumerations themselves
> already exist, eg. the IDs for nau8821 codec:
>
> /* System Clock Source */
> enum {
> NAU8821_CLK_DIS,
> NAU8821_CLK_MCLK,
> NAU8821_CLK_INTERNAL,
> NAU8821_CLK_FLL_MCLK,
> NAU8821_CLK_FLL_BLK,
> NAU8821_CLK_FLL_FS,
> };
OK, this looks good.
>
> We would just be moving these into dt-bindings if somebody wants to
> use a codec with simple-card. Future drivers would add the enum into
> dt-bindings from the start because that's where it belongs.
And the remaining piece I don't get is that these are not bindings for
codec, but for sound audio card. You want to set "system-clock-id"
property for audio card, while putting clock from codec, which will be
used to pass back to the codec... so it is a property of the codec, not
of the audio card. IOW, NAU8821_CLK_* does not configure here the clock
of the system, but only, only clock of the codec.
Best regards,
Krzysztof
