Re: [PATCH v5 1/2] dt-bindings: phy: qcom: Add CSI2 C-PHY/DPHY schema

Konrad Dybcio
2026-03-27T10:07:10Z

On 3/26/26 2:04 AM, Bryan O'Donoghue wrote:
> Add a base schema initially compatible with x1e80100 to describe MIPI CSI2
> PHY devices.
>
> The hardware can support both CPHY, DPHY and a special split-mode DPHY. We
> capture those modes as:
>
> - PHY_QCOM_CSI2_MODE_DPHY
> - PHY_QCOM_CSI2_MODE_CPHY
> - PHY_QCOM_CSI2_MODE_SPLIT_DPHY

Does the _PHY_ DT node need to be aware about this upfront?

If we have some sideband signal (e.g. the sensor driver specifically
requesting C-PHY mode), we can simply throw all this complexity into
phy_mode + phy_configure_opts, all at runtime

Further, the combo/split mode may possibly be selected through
aggregation of requests.

The question remains whether the sensor should have a direct connection to
the PHY itself (i.e. phys = <&csiphyN> or of_graph straight into the PHY)
or whether it's going to be translated by the camss node (which would be
the one holding a PHY reference) - there's probably surface for adding such
negotiation logic in both places

Note this is a question and I'm not aware of all the possible combinations

Konrad