Re: [PATCH v11 2/3] ASoC: qcom: dt-bindings: Add sc7180 machine bindings

[Cheng-yi Chiang <cychiang@chromium.org>]

Sorry for resending this mail.
I forgot to use plain text mode in the previous mail.
On Thu, Oct 22, 2020 at 6:12 PM Srinivas Kandagatla
<srinivas.kandagatla@linaro.org> wrote:
>
>
>
> On 22/10/2020 04:29, Tzung-Bi Shih wrote:
> > Hi, sorry for jumping into your discussion but I am trying to
> > summarize them to make sure we are on the same page.  Pardon me to
> > manually copy-and-paste partial sentences to quote.
> >
> > ACK:
> > - Don't expose DAI connections in compatible strings.
> > - Use "model" DT property to make the card more UCM2-friendly.
> > - Expose new DT properties to distinguish different DMIC models.
> >
> > NACK:
> > - All the board variations using exactly the same compatible string.
> > => This is less realistic.  Although the CODECS information can be
> > retrieved from DT, it is inevitable to have some custom code for each
> > CODEC.
> >
> > Per Mark's words:
> >> a different CODEC is something that often justifies a separate compatible
> > I think we should use different compatible strings for new CODECS
> > combinations.  And we should try to reuse the machine driver if they
> > share the most code.  In the worst case, introduce a new machine
> > driver for the new CODECS combinations.
> >
> > - Srinivas's suggestion to set driver_name.
> > e.g. card->driver_name = "SM8250";
> > => This sounds like a new DT property should be parsed in
> > sound/soc/qcom/common.c.  For example: "qcom,family"?  But as we do
> > less care about UCM2 for now, I would prefer to just leave it as is.
> >
> No, you can just hardcode this driver_name in your machine driver rather
> than getting it from DT, this is how everyone does!.
> So need of adding anything to common.c
>
ACK
> The thing that I suggested to add to common.c is setting card->long_name
> from "model" property.
>

NACK
I found that I don't need to set card->long_name in common.c because
soc-core.c already sets longname using card->name if
card->long_name is NULL.

        soc_setup_card_name(card->snd_card->longname,
                            card->long_name, card->name, 0);

So we can leave common.c as it is and still get long name.

> >
> > I would expect the following variants in DTS (just for example):
> >
> > sound {
> >    compatible = "qcom,sc7180-trogdor";
> Make sure that vendor name is correct here, am not sure if trogdor is
> qcom board or Google own board!
ACK
I should use "google,sc7180-trogdor" because google is the vendor.
>
> >    model = "sc7180-rt5682-max98357a-1mic";
> > }
> >
> > sound {
> >    compatible = "qcom,sc7180-trogdor";
> >    model = "sc7180-rt5682-max98357a-2mic";
> >    dmic-gpio = ...
> > }
> >
> > sound {
> >    compatible = "qcom,sc7180-pompom";
> >    model = "sc7180-adau7002-max98357a";
> > }
> >
> >
> > Please correct me if there is any misunderstanding.
>
> Looks good to me!
> thanks for doing this!
Thank you. I will collect the discussion result to send a v12, and
sync with variant board partners to submit following machine driver
changes.
We will make sure future projects follow this approach
>
> --srini
> >