Re: [PATCH v3 1/4] dt-bindindgs: i2c: qcom,i2c-geni: Document shared flag

Krzysztof Kozlowski
2024-09-27T09:24:51Z

On Fri, Sep 27, 2024 at 12:01:05PM +0530, Mukesh Kumar Savaliya wrote:
> Adds qcom,shared-se flag usage. Use this when particular I2C serial
> controller needs to be shared between two subsystems.
>
> SE = Serial Engine, meant for I2C controller here.
> TRE = Transfer Ring Element, refers to Queued Descriptor.
> SS = Subsystems (APPS processor, Modem, TZ, ADSP etc).
>
> Example :
> Two clients from different SS can share an I2C SE for same slave device
> OR their owned slave devices.
> Assume I2C Slave EEPROM device connected with I2C controller.
> Each client from ADSP SS and APPS Linux SS can perform i2c transactions.
> This gets serialized by lock TRE + DMA Transfers + Unlock TRE at HW level.
>
> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
> ---
> Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml b/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml
> index 9f66a3bb1f80..3b9b20a0edff 100644
> --- a/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml
> +++ b/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml
> @@ -60,6 +60,10 @@ properties:
> power-domains:
> maxItems: 1
>
> + qcom,shared-se:
> + description: True if I2C needs to be shared between two or more subsystems(SS).

The "SS" and subsystem should be explained in the binding. Please do not
use some qcom-specific abbreviations here, but explain exactly, e.g.
processors like application processor and DSP.

"se" is also not explained in the binding - please open it and look for
such explanation.

This all should be rephrased to make it clear... We talked about this
and I do not see much of improvements except commit msg, so we are
making circles. I don't know, get someone internally to help you in
upstreaming this.

Is sharing of IP blocks going to be also for other devices? If yes, then
this should be one property for all Qualcomm devices. If not, then be
sure that this is the case because I will bring it up if you come with
one more solution for something else.

Best regards,
Krzysztof