Re: [PATCH v2 1/3] ASoC: dt-bindings: qcom,lpass-va-csr: Add HeartBeat pulse clock

[Krzysztof Kozlowski]

On 16/07/2026 21:51, Sarath Ganapathiraju via B4 Relay wrote:
> From: Sarath Ganapathiraju <sarath.ganapathiraju@xxxxxxxxxxxxxxxx>
> 
> Add Qualcomm LPASS VA CSR rate generator node that exposes
> the lpass_heartbeat_pulse clock on hawi.
> 
> The HeartBeat Pulse (also known as RateGen Pulse) synchronizes the
> start of the DMAs and Codec Interfaces for the audio usecase
> and can serve as a periodic wakeup source for the DSP.
> 
> Signed-off-by: Sarath Ganapathiraju <sarath.ganapathiraju@xxxxxxxxxxxxxxxx>
> ---
>  .../bindings/sound/qcom,lpass-va-csr.yaml          | 52 ++++++++++++++++++++++
>  1 file changed, 52 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/sound/qcom,lpass-va-csr.yaml b/Documentation/devicetree/bindings/sound/qcom,lpass-va-csr.yaml
> new file mode 100644
> index 0000000000..131debb04f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/qcom,lpass-va-csr.yaml
> @@ -0,0 +1,52 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/sound/qcom,lpass-va-csr.yaml#

I do not understand why a clock controller is part of sound. This makes
little sense and desription does not help me.

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm LPASS VA CSR heartbeat pulse clock provider
> +
> +maintainers:
> +  - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
> +  - Sarath Ganapathiraju <sarath.ganapathiraju@xxxxxxxxxxxxxxxx>
> +
> +description:
> +  The LPASS VA CSR block contains the rate generator hardware which
> +  produces the heartbeatpulse consumed by the Bolero codec macros
> +  (rx, tx, wsa, va). It is modelled as a clock provider
> +  so consumers can reference it by name in their clocks list.

Drop last syntax, explain the hardware, not duplicate schema as text.

> +
> +properties:
> +  compatible:
> +    enum:
> +      - qcom,hawi-lpass-va-csr
> +
> +  reg:
> +    maxItems: 1
> +    description: Must cover the full VA CSR block (base 0x7EE0000, size 0xE000).

Drop description, redundant. Why would not device MMIO address range
cover full block?

> +
> +  "#clock-cells":
> +    const: 0
> +    description:
> +      Single clock output "lpass_heartbeat_pulse". Consumers reference
> +      it by clock-name "heartbeatpulse" in their clocks list.

Drop description. Not even accurate. Consumers reference it however they
wish and it is not any business of the provider.

>From where did you take such style?

> +
> +required:
> +  - compatible
> +  - reg
> +  - "#clock-cells"
> +
> +unevaluatedProperties: false

And this...

> +
> +examples:
> +  - |
> +    soc {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      va-csr@7ee0000 {

Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
If you cannot find a name matching your device, please check in kernel
sources for similar cases or you can grow the spec (via pull request to
DT spec repo).

> +        compatible = "qcom,hawi-lpass-va-csr";
> +        reg = <0x0 0x07ee0000 0x0 0xe000>;
> +        #clock-cells = <0>;
> +      };
> +    };
> 


Best regards,
Krzysztof