Re: [PATCH 1/2] dt-bindings: usb: Add Intel SoCFPGA USB controller bindings

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 21/07/2023 06:30, adrian.ho.yin.ng@intel.com wrote:
> From: Adrian Ng Ho Yin <adrian.ho.yin.ng@intel.com>
> 
> Existing binding intel,keembay-dwc3.yaml does not have the required
> properties for Intel SoCFPGA devices.
> Introduce new binding description for Intel SoCFPGA USB controller
> which will be used for current and future SoCFPGA devices.
> 
> Signed-off-by: Adrian Ng Ho Yin <adrian.ho.yin.ng@intel.com>

A nit, subject: drop second/last, redundant "bindings". The
"dt-bindings" prefix is already stating that these are bindings.

> ---
>  .../bindings/usb/intel,socfpga-dwc3.yaml      | 78 +++++++++++++++++++
>  1 file changed, 78 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/intel,socfpga-dwc3.yaml

Filename matching compatible.

> 
> diff --git a/Documentation/devicetree/bindings/usb/intel,socfpga-dwc3.yaml b/Documentation/devicetree/bindings/usb/intel,socfpga-dwc3.yaml
> new file mode 100644
> index 000000000000..dedef70df887
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/intel,socfpga-dwc3.yaml
> @@ -0,0 +1,78 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/intel,socfpga-dwc3.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Intel SoCFPGA DWC3 USB controller
> +
> +maintainers:
> +  - Adrian Ng Ho Yin <adrian.ho.yin.ng@intel.com>
> +
> +properties:
> +  compatible:
> +    const: intel,agilex5-dwc3

Why using compatible style different than other Agilex blocks? Which one
is recommended/official/correct?

> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 2

What are the items?

> +
> +  ranges: true
> +
> +  resets:
> +    maxItems: 2
> +
> +  reset-names:
> +    items:
> +      - const: dwc3
> +      - const: dwc3-ecc
> +
> +  '#address-cells':
> +    enum: [ 1, 2 ]
> +
> +  '#size-cells':
> +    enum: [ 1, 2 ]
> +
> +# Required child node:
> +
> +patternProperties:
> +  "^usb@[0-9a-f]+$":
> +    $ref: snps,dwc3.yaml#
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - resets
> +  - ranges
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/reset/altr,rst-mgr.h>
> +    #define AGILEX5_USB31_SUSPEND_CLK
> +    #define AGILEX5_USB31_BUS_CLK_EARLY

Drop defines. Include proper header or use some numbers, if the headers
are not there yet.

> +
> +    usb1@11000000 {

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


> +          compatible = "intel,agilex5-dwc3";
Best regards,
Krzysztof