[RFC PATCH] dt-bindings: phy: Add Qualcomm MIPI C-/D-PHY schema for CSIPHY IPs

[Vladimir Zapolskiy]

Hello Krzysztof.

On 5/14/25 13:25, Krzysztof Kozlowski wrote:
> On 13/05/2025 16:39, Vladimir Zapolskiy wrote:
>> Add dt-binding schema for the CAMSS CSIPHY IPs, which provides
>> MIPI C-/D-PHY interfaces on Qualcomm SoCs.
>>
>> Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy at linaro.org>
>> ---
>>   .../devicetree/bindings/phy/qcom,csiphy.yaml  | 110 ++++++++++++++++++
>>   1 file changed, 110 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/phy/qcom,csiphy.yaml
> 
> 
> Looks like not tested, so limited review follows.
> 
> Filename matching compatible.
> 

Thank you for the review, the change is deliberately tagged as RFC.

I read this review comment as the displayed generic compatible 'qcom,csiphy'
shall be added to the list of compatibles.

>>
>> diff --git a/Documentation/devicetree/bindings/phy/qcom,csiphy.yaml b/Documentation/devicetree/bindings/phy/qcom,csiphy.yaml
>> new file mode 100644
>> index 000000000000..ef712c5442ec
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/phy/qcom,csiphy.yaml
> 
> Please post the driver or any other user. Or explain why this is RFC or
> what you expect here from us.
> 

The CSIPHY driver agnostic CAMSS changes are on the linux-media list [1], the CSIPHY
driver specific changes will be added on top of these changes, however I believe
it makes sense to review these two different CAMSS changesets independently.

Here the RFC tag is given explicitly to get change reviews for the dt binding
documentation part, and the first user is the example embedded into the change.

>> @@ -0,0 +1,110 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/phy/qcom,csiphy.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Qualcomm CSI PHY
> 
> SM8250 ?
> 

It's supposed to be a generic device tree binding, and it covers SM8250
CAMSS CSIPHY IP as well, which could be quite handly for testing/review.

>> +
>> +maintainers:
>> +  - Vladimir Zapolskiy <vladimir.zapolskiy at linaro.org>
>> +
>> +description: |
> 
> Do not need '|' unless you need to preserve formatting.
> 

Ack.

>> +  Qualcomm SoCs equipped with a number of MIPI CSI PHY IPs, which
>> +  supports D-PHY or C-PHY interfaces to camera sensors.
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - qcom,sm8250-csiphy
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    maxItems: 2
> 
> Need to list the items instead
> 

Ack.

>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  vdda-csi-0p9-supply:
>> +    description: Voltage supply, 0.9V
>> +
>> +  vdda-csi-1p2-supply:
>> +    description: Voltage supply, 1.2V
>> +
>> +  '#phy-cells':
>> +    const: 0
>> +
>> +  port:
>> +    $ref: /schemas/graph.yaml#/$defs/port-base
>> +    description: CAMSS CSIPHY input port
>> +
>> +    patternProperties:
>> +      "^endpoint@[0-1]$":
> 
> Keep consistent quotes, either " or '
> 

Ack.

>> +        $ref: /schemas/media/video-interfaces.yaml#
>> +        unevaluatedProperties: false
>> +
>> +        properties:
>> +          data-lanes:
>> +            minItems: 1
>> +            maxItems: 4
>> +
>> +          bus-type:
>> +            enum:
>> +              - 1 # MEDIA_BUS_TYPE_CSI2_CPHY
>> +              - 4 # MEDIA_BUS_TYPE_CSI2_DPHY
>> +
>> +        required:
>> +          - data-lanes
>> +
>> +    oneOf:
>> +      - required:
>> +          - endpoint
>> +      - required:
>> +          - endpoint at 0
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - clocks
>> +  - interrupts
>> +  - '#phy-cells'
>> +
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - qcom,sm8250-csiphy
>> +    then:
>> +      required:
>> +        - vdda-csi-0p9-supply
>> +        - vdda-csi-1p2-supply
> 
> This makes no sense - it is only sm8250 - so this if is always true.
> 

Ack, thank you for the review comments.

--
Best wishes,
Vladimir