Re: [PATCH v3 8/9] arm64: dts: qcom: sdm670: add digital audio codec

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] arm64: dts: qcom: sdm670: dummy fixed-clock lpass-cdc-bclk
  used for ahbix-clk
--

commit b9856161fbdcddf34face16a0ba725a6845da3f8
Author: Richard Acayan <mailingradian@gmail.com>

arm64: dts: qcom: sdm670: add digital audio codec

This commit adds the LPASS digital WCD audio codec node and its clocks to
the SDM670 SoC device tree.

> diff --git a/arch/arm64/boot/dts/qcom/sdm670.dtsi b/arch/arm64/boot/dts/qcom/sdm670.dtsi
> index e99183c222083..3e5ca16e30565 100644
> --- a/arch/arm64/boot/dts/qcom/sdm670.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm670.dtsi
[ ... ]
> @@ -33,6 +34,12 @@ / {
>  	chosen { };
>  
>  	clocks {
> +		lpass_cdc_bclk: lpass-cdc-bclk {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +			clock-frequency = <1536000>;
> +		};
> +
>  		sleep_clk: sleep-clk {
>  			compatible = "fixed-clock";
>  			#clock-cells = <0>;
> @@ -2822,5 +2829,20 @@ data2-pins {
>  				};
>  			};
>  		};
> +
> +		lpass_codec: audio-codec@62ec0000 {
> +			compatible = "qcom,sdm670-wcd-digital-codec",
> +				     "qcom,msm8916-wcd-digital-codec";
> +			reg = <0 0x62ec0000 0 0x400>;
> +
> +			clocks = <&lpass_cdc_bclk>,
> +				 <&q6afecc LPASS_CLK_ID_INT_MCLK_0 LPASS_CLK_ATTRIBUTE_COUPLE_NO>;
> +			clock-names = "ahbix-clk", "mclk";

[Severity: Medium]
As reported by Konrad Dybcio on v2 [1], should ahbix-clk be wired to
q6afecc (or made optional in the binding and driver if HLOS does not vote
for it on SDM670) instead of a dummy 1.536 MHz fixed-clock under /clocks?

In Qualcomm SoC devicetrees, /clocks is reserved for board-level reference
clocks, and ahbix-clk is the LPASS AHB interface clock for codec register
access rather than a bit clock.  Wiring it to a fixed-clock puts a fake
clock in the devicetree and bypasses Q6AFE LPASS digital codec clock
voting (such as LPASS_CLK_ID_INTERNAL_DIGITAL_CODEC_CORE or
LPASS_HW_DCODEC_VOTE).

[1] https://lore.kernel.org/r/87839ad6-c489-40b3-bfcc-60c436cd1a6f@oss.qualcomm.com

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261107022453.159341-1-mailingradian@gmail.com?part=8