On Mon, Apr 06, 2020 at 03:56:07PM +0200, Stephan Gerhold wrote:
> The lpass-cpu driver now allows configuring the MI2S SD lines
> by defining subnodes for one of the DAIs.
>
> Document this in the device tree bindings.
>
> Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
> ---
> .../bindings/sound/qcom,lpass-cpu.txt | 23 +++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt b/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt
> index 21c648328be9..df53a10502f7 100644
> --- a/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt
> +++ b/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt
> @@ -30,6 +30,8 @@ Required properties:
> - reg : Must contain an address for each entry in reg-names.
> - reg-names : A list which must include the following entries:
> * "lpass-lpaif"
> +- #address-cells : Must be 1
> +- #size-cells : Must be 0
>
>
>
> @@ -37,6 +39,18 @@ Optional properties:
>
> - qcom,adsp : Phandle for the audio DSP node
>
> +By default, the driver uses up to 4 MI2S SD lines, for a total of 8 channels.
> +The SD lines to use can be configured by adding subnodes for each of the DAIs.
> +
> +Required properties for each DAI (represented by a subnode):
> +- reg : Must be one of the DAI IDs
> + (usually part of dt-bindings header)
> +- qcom,playback-sd-lines: List of serial data lines (0-3) to use for playback
0-3 for the values or number of entries?
> +- qcom,capture-sd-lines : List of serial data lines (0-3) to use for capture
> +
> +Note that adding a subnode changes the default to "no lines configured",
> +so both playback and capture lines should be configured when a subnode is added.
> +
> Example:
>
> lpass@28100000 {
> @@ -51,4 +65,13 @@ lpass@28100000 {
> reg = <0x28100000 0x10000>;
> reg-names = "lpass-lpaif";
> qcom,adsp = <&adsp>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + /* Optional to set different MI2S SD lines */
> + mi2s-quaternary@3 {
Normally the node name reflects the class of device. IOW, all the child
nodes should have the same name.
> + reg = <MI2S_QUATERNARY>;
> + qcom,playback-sd-lines = <0 1>;
> + };
> };
> --
> 2.26.0
>
