On Tue, Oct 29, 2024 at 11:05 AM Trevor Wu (吳文良) <Trevor.Wu@xxxxxxxxxxxx> wrote: > > On Mon, 2024-10-28 at 15:25 +0100, AngeloGioacchino Del Regno wrote: > > External email : Please do not click links or open attachments until > > you have verified the sender or the content. > > > > > > Il 28/10/24 12:10, Fei Shao ha scritto: > > > On Mon, Oct 28, 2024 at 4:54 AM Krzysztof Kozlowski < > > > krzk@xxxxxxxxxx> wrote: > > > > > > > > On Fri, Oct 25, 2024 at 06:44:41PM +0800, Fei Shao wrote: > > > > > Add "mediatek,adsp" property for the ADSP handle if ADSP is > > > > > enabled on > > > > > the platform. > > > > > > > > We see this from the diff. > > > > > > > > > Add "mediatek,dai-link" property for the required DAI links to > > > > > configure > > > > > sound card. > > > > > > > > We see this from the diff. > > > > > > > > > > > > > > Both properties are commonly used in the MediaTek sound card > > > > > driver. > > > > > > > > If they are used, why suddenly they are needed? What changed? > > > > > > Nothing has changed. These should have been added altogether when > > > the > > > binding was first introduced. This patch is to fill the gaps and > > > fix > > > dtbs_check warnings, like I mentioned in the cover letter. > > > I can add a line in the commit message saying it's to fix the > > > warning > > > in addition to the cover letter, if that's preferred. > > > > > > > > > > > > > > > > > Signed-off-by: Fei Shao <fshao@xxxxxxxxxxxx> > > > > > --- > > > > > > > > > > .../bindings/sound/mediatek,mt8188-mt6359.yaml | 10 > > > > > ++++++++++ > > > > > 1 file changed, 10 insertions(+) > > > > > > > > > > diff --git > > > > > a/Documentation/devicetree/bindings/sound/mediatek,mt8188- > > > > > mt6359.yaml > > > > > b/Documentation/devicetree/bindings/sound/mediatek,mt8188- > > > > > mt6359.yaml > > > > > index f94ad0715e32..701cedfa38d2 100644 > > > > > --- a/Documentation/devicetree/bindings/sound/mediatek,mt8188- > > > > > mt6359.yaml > > > > > +++ b/Documentation/devicetree/bindings/sound/mediatek,mt8188- > > > > > mt6359.yaml > > > > > @@ -29,6 +29,16 @@ properties: > > > > > $ref: /schemas/types.yaml#/definitions/phandle > > > > > description: The phandle of MT8188 ASoC platform. > > > > > > > > > > + mediatek,adsp: > > > > > + $ref: /schemas/types.yaml#/definitions/phandle > > > > > + description: The phandle of MT8188 ADSP platform. > > > > > > > > And what is the difference between ASoC and ADSP platforms? What > > > > are > > > > they used for? > > > > > > I'm not a MediaTek or audio folks, and I'm afraid that I'm not the > > > best person to explain the details accurately in front of experts > > > on > > > the list... I know it's an audio DSP but that explains nothing. > > > MediaTek didn't provide a meaningful explanation in the tree or > > > commits, and I want to avoid adding additional but likely > > > misleading > > > descriptions from someone who doesn't have enough knowledge, > > > potentially causing even more confusing situations in the future. > > > Plus, the same changes were accepted as-is in the past, so I > > > assumed > > > they might be self-explanatory to people who are familiar with the > > > matter. > > > > > > > The Audio DSP is a Tensilica HiFi-5 DSP, and it's a block that is - > > hardware > > speaking - separated from the rest of the Audio interfaces of the > > SoC. > > > > The whole sound subsystem can work either with or without the DSP, in > > the sense > > that the DSP itself can remain unpowered and completely unconfigured > > if its > > functionality is not desired - hence, this is a board specific > > configuration: > > if the board wants to use the DSP, we use the DSP - otherwise, we > > just don't. > > > > Regarding the two "platforms", in short: > > "mediatek,platform" -> Audio Front End (AFE) > > "mediatek,adsp" -> Audio DSP > > > > Now, you can either link the AFE DAIs to the I2S > > > > As for "mediatek,platform" - that's used to link the Analog Front End > > (AFE) as > > the DAI Link platform (so the path is direct to/from DL/UL DAIs to > > AFE) or the > > ADSP one as the DAI Link platform (so that the path is to/from DL/UL > > DAIs to > > DSP to AFE), but that - of course - still requires an AFE, otherwise > > you cannot > > get the audio out of the speakers or in from the mic anyway. > > > > > > > > > > > + > > > > > + mediatek,dai-link: > > > > > + $ref: /schemas/types.yaml#/definitions/string-array > > > > > + description: > > > > > + A list of the desired dai-links in the sound card. Each > > > > > entry is a > > > > > + name defined in the machine driver. > > > > > > > > The list is provided below. I don't understand why do you need > > > > it. Your > > > > msg is pretty useless - you describe what you do, instead of why. > > > > > > I think this is used to explicitly list the intermediate but hidden > > > DAIs, but again, there's not much info about them unless MediaTek > > > can > > > explain more details and why they need a vendor property for this. > > > > > > > Yes, this is used for exactly that... but I believe that we can > > deprecate this > > now that we have support for the "standard" `audio-routing` property > > and for the > > DAI Link nodes (examples that you can find in current device trees > > are mm-dai-link, > > hs-playback-dai-link, or any other subnode of the sound card). > > > > Specifically, those subnodes *do* require a "link-name" property, > > which *does* > > effectively contain the same DAI Link names as the ones that are > > inside of the > > "mediatek,dai-link" property. > > > > On MT8195, you can find both the subnodes and the mediatek,dai-link - > > yes - but > > that was done to retain compatibility of the device tree with old > > drivers (so, > > an unusual case of new device tree on old kernel). > > > > Finally, I believe that we can avoid adding that "mediatek,dai-link" > > property > > to the MT8188 binding, and rely on: > > 1. Whatever is provided in struct snd_soc_card for that device; and > > 2. Whatever is provided in device trees as dai link subnodes, which > > would > > restrict N.1 as that's anyway describing card prelinks. > > > > The "mediatek,dai-link" property is utilized to hide the unused dai- > links in the sound card. By hiding the unused FE links, it can save the > necessary memory and prevent conflicts where both the DSP and AP > control the same AFE Memifs. > > This concept was first implemented in mt8195 as Mark aimed to avoid the > need for a separate driver for different system configurations. > With the introduction of DSP (SOF), if certain AFE Memifs are already > in use in the DSP route, they should be excluded from the PCM nodes > created for the AFE platform. > > At that time, we did not have a better way to handle these scenarios, > so we made use of a vendor-defined property. > > It has been a while since I last kept up with the updates in mt8188, so > I'm uncertain if the current mechanism for sound card description is > sufficient for handling such scenarios. If it is, I agree that we can > deprecate such a vendor property from mt8188. > > Thanks, > Trevor > > > > Cheers, > > Angelo Many thanks Angelo and Trevor for the information. The audio-routing property is in place, so I'll check if removing the vendor property makes any impact, and refresh the series accordingly. Thanks, Fei > > > > > Regards, > > > Fei > > > > > > > > > > > Best regards, > > > > Krzysztof > > > > > > > >
