On 23/09/2022 11:56, Chancel Liu wrote: >>> Add a string property to assign the rpmsg channel this sound card sits >>> on. It also represents the name of ASoC platform driver. This property >>> can be omitted if there is only one sound card and it sits on >>> "rpmsg-audio-channel". >>> >>> Signed-off-by: Chancel Liu <chancel.liu@xxxxxxx> >>> --- >>> .../devicetree/bindings/sound/fsl,rpmsg.yaml | 37 ++++++++++++++++++- >>> 1 file changed, 35 insertions(+), 2 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml >> b/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml >>> index d370c98a62c7..3744ae794c00 100644 >>> --- a/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml >>> +++ b/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml >>> @@ -11,8 +11,11 @@ maintainers: >>> >>> description: | >>> fsl_rpmsg is a virtual audio device. Mapping to real hardware devices >>> - are SAI, DMA controlled by Cortex M core. What we see from Linux >>> - side is a device which provides audio service by rpmsg channel. >>> + are SAI, MICFIL, DMA controlled by Cortex M core. What we see from >>> + Linux side is a device which provides audio service by rpmsg channel. >>> + We can create different sound cards which access different hardwares >>> + such as SAI, MICFIL, .etc through building rpmsg channels between >>> + Cortex-A and Cortex-M. >>> >>> properties: >>> compatible: >>> @@ -85,6 +88,17 @@ properties: >>> This is a boolean property. If present, the receiving function >>> will be enabled. >>> >>> + fsl,rpmsg-channel-name: >>> + $ref: /schemas/types.yaml#/definitions/string >>> + description: | >>> + A string property to assign rpmsg channel this sound card sits on. >>> + It also represents the name of ASoC platform driver. This property >> >> That's a Linux detail which doesn't belong in DT. >> > > We pass hardware parameters in dts node to set up clocks or other > configurations. These configurations are finally sent to Cortex-M by > rpmsg channel because Cortex-M actually controls real hardware devices. > If there's only one sound card sits on one rpmsg channel we will not > need this property. But if there are several sound cards we need to > specify correct rpmsg channel. Thus hardware configurations can be > properly sent to Cortex-M. From this level to speak, this property is > hardware-related since rpmsg channel represents the real hardware audio > controller. > > Here I attach the discussion in version 1 patches for your information: > --- > This property aims to tell the ASoC driver which rpmsg channel the > sound card depends on. If there are several sound cards sit on rpmsg, > we should pass correct information in dts node to specify the name of > rpmsg channel. That is why I meant to add this property. > > Actually this property is hardware-related. As we discussed before, > this kind of sound card based on rpmsg works under this mechanism > Cortex-A core tells the Cortex-M core configuration of the PCM > parameters then Cortex-M controls real hardware devices. This property > specifying rpmsg channel represents the real hardware audio controller. > --- > > That's my idea adding this property. Do you have any suggstion? I think you misunderstood the comment. Rob's comment was directly below a line which he referred to. That line contained a statement referring to Linux drivers. Anything related to Linux drivers does not belong to DT. Best regards, Krzysztof
