Re: [PATCH 2/3] dt-bindings: usb: Introduce samsung,snps-dwc3

[Krzysztof Kozlowski <krzk@kernel.org>]

On 03/09/2026 09:12, Selvarasu Ganesan wrote:
> The Samsung Exynos8855 USB glue is not separate from the Synopsys DWC3
> core, using a flattened model where the DWC3 controller is directly
> addressable rather than nested as a child node of a glue layer.
> 
> Describe the Exynos USB block as a single node, referencing the split
> out Synopsys DWC3 core properties via snps,dwc3-common.yaml. The new
> binding follows the same approach as qcom,snps-dwc3.
> 
> A generic fallback compatible "samsung,snps-dwc3" is introduced to
> describe this binding, selected by the validator based on the presence
> of the fallback string in the compatible list. Future Exynos SoCs

This is AI slop text. Over longish useless sentence describing diff
without actual information WHY.

Don't send AI generated slop messages.

> utilizing the same flattened model can be added by extending the
> compatible enum with per SoC clock and property constraints.
> 
> Co-developed-by: Muhammed Ali <muhammed.ali@samsung.com>
> Signed-off-by: Muhammed Ali <muhammed.ali@samsung.com>
> Signed-off-by: Selvarasu Ganesan <selvarasu.g@samsung.com>
> ---
> 
> Krzysztof Kozlowski is added as a maintainer of this YAML binding, as
> he is the ARM/Samsung SoC architecture maintainer (ARM/SAMSUNG S3C,
> S5P AND EXYNOS ARM ARCHITECTURES) who already maintains Samsung Exynos
> DT bindings (e.g. samsung,exynos-dwc3.yaml) and reviews all
> Samsung related binding changes. This follows the same convention used
> by existing Samsung Exynos DT binding schemas.
> ---
>  .../bindings/usb/samsung,snps-dwc3.yaml       | 98 +++++++++++++++++++
>  1 file changed, 98 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/samsung,snps-dwc3.yaml
> 
> diff --git a/Documentation/devicetree/bindings/usb/samsung,snps-dwc3.yaml b/Documentation/devicetree/bindings/usb/samsung,snps-dwc3.yaml
> new file mode 100644
> index 000000000000..480308c16f37
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/samsung,snps-dwc3.yaml
> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/samsung,snps-dwc3.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Samsung Exynos SoC DWC3 USB Controller
> +
> +maintainers:
> +  - Krzysztof Kozlowski <krzk@kernel.org>
> +  - Selvarasu Ganesan <selvarasu.g@samsung.com>
> +
> +description:
> +  Describes the DWC3 USB controller block implemented on Samsung Exynos SoCs.

Huh? Did you even look at existing bindings?

> +
> +select:
> +  properties:
> +    compatible:
> +      contains:
> +        const: samsung,snps-dwc3
> +  required:
> +    - compatible
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - samsung,exynos8855-dwc3
> +      - const: samsung,snps-dwc3

There is no snps device from Samsung, neither DWC3. The name of device
is completely wrong. snps is a vendor, not a device.

Anyway, don't use generic fallbacks.



> +
> +  reg:
> +    maxItems: 1
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    description: |
> +      Several clocks are used, depending on the variant. Typical ones are:
> +       - ref: Reference clock for SOF/ITP generation.
> +       - bus: Bus (APB) clock for register access.
> +    minItems: 1
> +    maxItems: 4
> +
> +  clock-names:
> +    minItems: 1
> +    maxItems: 4

You have only one device, why is this flexible?

> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - interrupts
> +
> +allOf:
> +  - $ref: snps,dwc3-common.yaml#
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: samsung,exynos8855-dwc3
> +    then:
> +      properties:
> +        clocks:
> +          minItems: 2
> +          maxItems: 2
> +        clock-names:
> +          items:
> +            - const: ref
> +            - const: bus

Why do you need all this? Look at existing code, don't duplicate. And
for sure do not introduce one more DWC3 binding claiming to be for
Samsung devices and completely ignoring existing ones.

Best regards,
Krzysztof