Re: [PATCH v4 5/5] dt-bindings: phy: realtek: Add the doc about the Realtek SoC USB 3.0 PHY

[Krzysztof Kozlowski]

On 14/06/2023 11:28, Stanley Chang wrote:
> Add the documentation explain the property about Realtek USB PHY driver.
> 
> Realtek DHC (digital home center) RTD SoCs support DWC3 XHCI USB
> controller. Added the driver to drive the  USB 3.0 PHY transceivers.
> 
> Signed-off-by: Stanley Chang <stanley_chang@xxxxxxxxxxx>
> ---
> v3 to v4 change:
>     1. Remove the parameter and non hardware properties from dts.
>     2. Using the compatible data included the config and parameter
>        in driver.
> v2 to v3 change:
>     1. Broken down into two patches, one for each of USB 2 & 3.
>     2. Add more description about Realtek RTD SoCs architecture.
>     3. Removed parameter v1 support for simplification.
>     4. Revised the compatible name for fallback compatible.
>     5. Remove some properties that can be set in the driver.
> v1 to v2 change:
>     Add phy-cells for generic phy driver
> ---
>  .../bindings/phy/realtek,usb3phy.yaml         | 105 ++++++++++++++++++
>  1 file changed, 105 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/realtek,usb3phy.yaml
> 
> diff --git a/Documentation/devicetree/bindings/phy/realtek,usb3phy.yaml b/Documentation/devicetree/bindings/phy/realtek,usb3phy.yaml
> new file mode 100644
> index 000000000000..0f849cf942e8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/realtek,usb3phy.yaml
> @@ -0,0 +1,105 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2023 Realtek Semiconductor Corporation
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/phy/realtek,usb3phy.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Realtek DHC SoCs USB 3.0 PHY
> +
> +maintainers:
> +  - Stanley Chang <stanley_chang@xxxxxxxxxxx>
> +
> +description:
> +  Realtek USB 3.0 PHY support the digital home center (DHC) RTD series SoCs.
> +  The USB 3.0 PHY driver is designed to support the XHCI controller. The SoCs
> +  support multiple XHCI controllers. One PHY device node maps to one XHCI
> +  controller.
> +
> +  RTD1295/RTD1619 SoCs USB
> +  The USB architecture includes three XHCI controllers.
> +  Each XHCI maps to one USB 2.0 PHY and map one USB 3.0 PHY on some
> +  controllers.
> +  XHCI controller#0 -- usb2phy -- phy#0
> +                    |- usb3phy -- phy#0
> +  XHCI controller#1 -- usb2phy -- phy#0
> +  XHCI controller#2 -- usb2phy -- phy#0
> +                    |- usb3phy -- phy#0
> +
> +  RTD1319/RTD1619b SoCs USB
> +  The USB architecture includes three XHCI controllers.
> +  Each XHCI maps to one USB 2.0 PHY and map one USB 3.0 PHY on controllers#2.
> +  XHCI controller#0 -- usb2phy -- phy#0
> +  XHCI controller#1 -- usb2phy -- phy#0
> +  XHCI controller#2 -- usb2phy -- phy#0
> +                    |- usb3phy -- phy#0
> +
> +  RTD1319d SoCs USB
> +  The USB architecture includes three XHCI controllers.
> +  Each xhci maps to one USB 2.0 PHY and map one USB 3.0 PHY on controllers#0.
> +  XHCI controller#0 -- usb2phy -- phy#0
> +                    |- usb3phy -- phy#0
> +  XHCI controller#1 -- usb2phy -- phy#0
> +  XHCI controller#2 -- usb2phy -- phy#0
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - realtek,rtd1295-usb3phy
> +          - realtek,rtd1319-usb3phy
> +          - realtek,rtd1319d-usb3phy
> +          - realtek,rtd1619-usb3phy
> +          - realtek,rtd1619b-usb3phy
> +      - const: realtek,usb3phy

Drop last compatible, it is not used now. Does not make sense.

> +
> +  reg:
> +    description: PHY data registers

Drop description, it's obvious.

> +    maxItems: 1
> +
> +  "#phy-cells":
> +    const: 0
> +
> +  nvmem-cells:
> +    maxItems: 1
> +    description: A phandle to the tx lfps swing trim data provided by
> +      a nvmem device, if unspecified, default values shall be used.
> +
> +  nvmem-cell-names:
> +    items:
> +      - const: usb_u3_tx_lfps_swing_trim
> +
> +  realtek,amplitude-control-coarse-tuning:
> +    description:
> +      This adjusts the signal amplitude for normal operation and beacon LFPS.
> +      This value is a parameter for coarse tuning.
> +      For different boards, if the default value is inappropriate, this
> +      property can be assigned to adjust.

default:

> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 0
> +    maximum: 255
> +
> +  realtek,amplitude-control-fine-tuning:
> +    description:
> +      This adjusts the signal amplitude for normal operation and beacon LFPS.
> +      This value is used for fine-tuning parameters.
> +    $ref: /schemas/types.yaml#/definitions/uint32

default:

> +    minimum: 0
> +    maximum: 65535
> +


Best regards,
Krzysztof