Re: [PATCH v2 1/4] dt-bindings: usb: dwc3: Add Google Tensor G5 DWC3

[Krzysztof Kozlowski <krzk@kernel.org>]

On 08/10/2025 14:59, Roy Luo wrote:
> Document the device tree bindings for the DWC3 USB controller found in
> Google Tensor SoCs, starting with the G5 generation.
> 
> The Tensor G5 silicon represents a complete architectural departure from


G5 does not have a model number like G1-G4?

> previous generations (like gs101), including entirely new clock/reset
> schemes, top-level wrapper and register interface. Consequently,
> existing Samsung/Exynos DWC3 USB bindings and drivers are incompatible,

Do not reference drivers. Explain the hardware.

> necessitating this new device tree binding.
> 
> The USB controller on Tensor G5 is based on Synopsys DWC3 IP and features
> Dual-Role Device single port with hibernation support.
> 
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
>  .../bindings/usb/google,gs-dwc3.yaml          | 145 ++++++++++++++++++
>  1 file changed, 145 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/google,gs-dwc3.yaml
> 
> diff --git a/Documentation/devicetree/bindings/usb/google,gs-dwc3.yaml b/Documentation/devicetree/bindings/usb/google,gs-dwc3.yaml
> new file mode 100644
> index 000000000000..9eb0bf726e8d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/google,gs-dwc3.yaml
> @@ -0,0 +1,145 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (c) 2025, Google LLC
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/google,gs-dwc3.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Google Tensor Series (G5+) DWC3 USB SoC Controller
> +
> +maintainers:
> +  - Roy Luo <royluo@google.com>
> +
> +description: |


Do not need '|' unless you need to preserve formatting.

> +  Describes the DWC3 USB controller block implemented on Google Tensor SoCs,
> +  starting with the G5 generation. Based on Synopsys DWC3 IP, the controller
> +  features Dual-Role Device single port with hibernation add-on.
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - google,gs5-dwc3
> +
> +  reg:
> +    minItems: 3

Drop

> +    maxItems: 3
> +
> +  reg-names:
> +    description: |
> +      The following memory regions must present:
> +        - dwc3_core: Core DWC3 IP registers.
> +        - host_cfg_csr: Hibernation control registers.
> +        - usbint_csr: Hibernation interrupt registers.

Drop description or move it to items in reg. See other bindings.

> +    items:
> +      - const: dwc3_core
> +      - const: host_cfg_csr
> +      - const: usbint_csr
> +
> +  interrupts:
> +    minItems: 3

Drop

> +    maxItems: 3
> +
> +  interrupt-names:
> +    description: |
> +      The following interrupts must present:
> +        - dwc_usb3: Core DWC3 interrupt.
> +        - hs_pme_irq: High speed remote wakeup interrupt for hibernation.
> +        - ss_pme_irq: Super speed remote wakeup interrupt for hibernation.

From where did you get this style? Don't write bindings with chat gpt or
whatever other tool. it is a waste of our time.

> +    items:
> +      - const: dwc_usb3
> +      - const: hs_pme_irq
> +      - const: ss_pme_irq
> +
> +  clocks:
> +    minItems: 3
> +    maxItems: 3
> +
> +  clock-names:
> +    minItems: 3
> +    maxItems: 3

From where did you get such syntax?

> +
> +  resets:
> +    minItems: 5
> +    maxItems: 5
> +
> +  reset-names:
> +    items:
> +      - const: usbc_non_sticky
> +      - const: usbc_sticky
> +      - const: usb_drd_bus
> +      - const: u2phy_apb
> +      - const: usb_top_csr
> +
> +  power-domains:
> +    minItems: 2
> +    maxItems: 2
> +
> +  power-domain-names:
> +    description: |
> +      The following power domain must present:
> +          - usb_psw_pd: The child power domain of usb_top_pd. Turning it on puts the controller
> +                         into full power state, turning it off puts the controller into power
> +                         gated state.
> +          - usb_top_pd: The parent power domain of usb_psw_pd. Turning it on puts the controller
> +                         into power gated state, turning it off completely shuts off the
> +                         controller.

Same comments.


> +    items:
> +      - const: usb_psw_pd
> +      - const: usb_top_pd
> +
> +  iommus:
> +    maxItems: 1
> +
Best regards,
Krzysztof