Subject: Re: [PATCH v3 01/16] dt-bindings: usb: usb-hcd: Convert generic USB properties to DT schema

From: Chunfeng Yun <[email-masked]>
Date: Wed, 21 Oct 2020 11:00:36 +0800

On Tue, 2020-10-20 at 14:20 +0300, Serge Semin wrote:
> The generic USB HCD properties have been described in the legacy bindings
> text file: Documentation/devicetree/bindings/usb/generic.txt . Let's
> convert it' content into the USB HCD DT schema properties so all USB DT
          ^ its?
> nodes would be validated to have them properly utilized.
> 
> Signed-off-by: Serge Semin <[email-masked]>
> Reviewed-by: Rob Herring <[email-masked]>
> 
> ---
> 
> Changelog v2:
> - Discard '|' in all the new properties, since we don't need to preserve
>   the text formatting.
> - Convert abbreviated form of the "maximum-speed" enum restriction into
>   the multi-lined version of the list.
> - Drop quotes from around the string constants.
> ---
>  .../devicetree/bindings/usb/generic.txt       | 57 ------------
>  .../devicetree/bindings/usb/usb-hcd.yaml      | 88 +++++++++++++++++++
Do we need change the file name or modify it's title?
the title is "Generic USB Host Controller Device Tree Bindings", but
some generic properties, such as, dr_mode, usb-role-switch, otg related
ones, are usually used by DRD controller, this may cause some confusion.

>  2 files changed, 88 insertions(+), 57 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/usb/generic.txt
> 
> diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
> deleted file mode 100644
> index ba472e7aefc9..000000000000
> --- a/Documentation/devicetree/bindings/usb/generic.txt
> +++ /dev/null
> @@ -1,57 +0,0 @@
> -Generic USB Properties
> -
> -Optional properties:
> - - maximum-speed: tells USB controllers we want to work up to a certain
> -			speed. Valid arguments are "super-speed-plus",
> -			"super-speed", "high-speed", "full-speed" and
> -			"low-speed". In case this isn't passed via DT, USB
> -			controllers should default to their maximum HW
> -			capability.
> - - dr_mode: tells Dual-Role USB controllers that we want to work on a
> -			particular mode. Valid arguments are "host",
> -			"peripheral" and "otg". In case this attribute isn't
> -			passed via DT, USB DRD controllers should default to
> -			OTG.
> - - phy_type: tells USB controllers that we want to configure the core to support
> -			a UTMI+ PHY with an 8- or 16-bit interface if UTMI+ is
> -			selected. Valid arguments are "utmi" and "utmi_wide".
> -			In case this isn't passed via DT, USB controllers should
> -			default to HW capability.
> - - otg-rev: tells usb driver the release number of the OTG and EH supplement
> -			with which the device and its descriptors are compliant,
> -			in binary-coded decimal (i.e. 2.0 is 0200H). This
> -			property is used if any real OTG features(HNP/SRP/ADP)
> -			is enabled, if ADP is required, otg-rev should be
> -			0x0200 or above.
> - - companion: phandle of a companion
> - - hnp-disable: tells OTG controllers we want to disable OTG HNP, normally HNP
> -			is the basic function of real OTG except you want it
> -			to be a srp-capable only B device.
> - - srp-disable: tells OTG controllers we want to disable OTG SRP, SRP is
> -			optional for OTG device.
> - - adp-disable: tells OTG controllers we want to disable OTG ADP, ADP is
> -			optional for OTG device.
> - - usb-role-switch: boolean, indicates that the device is capable of assigning
> -			the USB data role (USB host or USB device) for a given
> -			USB connector, such as Type-C, Type-B(micro).
> -			see connector/usb-connector.yaml.
> - - role-switch-default-mode: indicating if usb-role-switch is enabled, the
> -			device default operation mode of controller while usb
> -			role is USB_ROLE_NONE. Valid arguments are "host" and
> -			"peripheral". Defaults to "peripheral" if not
> -			specified.
> -
> -
> -This is an attribute to a USB controller such as:
> -
> -dwc3@4a030000 {
> -	compatible = "synopsys,dwc3";
> -	reg = <0x4a030000 0xcfff>;
> -	interrupts = <0 92 4>
> -	usb-phy = <&usb2_phy>, <&usb3,phy>;
> -	maximum-speed = "super-speed";
> -	dr_mode = "otg";
> -	phy_type = "utmi_wide";
> -	otg-rev = <0x0200>;
> -	adp-disable;
> -};
> diff --git a/Documentation/devicetree/bindings/usb/usb-hcd.yaml b/Documentation/devicetree/bindings/usb/usb-hcd.yaml
> index 7263b7f2b510..ee7ea205c71d 100644
> --- a/Documentation/devicetree/bindings/usb/usb-hcd.yaml
> +++ b/Documentation/devicetree/bindings/usb/usb-hcd.yaml
> @@ -22,9 +22,97 @@ properties:
>      description:
>        Name specifier for the USB PHY
>  
> +  maximum-speed:
> +   description:
> +     Tells USB controllers we want to work up to a certain speed. In case this
> +     isn't passed via DT, USB controllers should default to their maximum HW
> +     capability.
> +   $ref: /schemas/types.yaml#/definitions/string
> +   enum:
> +     - low-speed
> +     - full-speed
> +     - high-speed
> +     - super-speed
> +     - super-speed-plus
> +
> +  dr_mode:
> +    description:
> +      Tells Dual-Role USB controllers that we want to work on a particular
> +      mode. In case this attribute isn't passed via DT, USB DRD controllers
> +      should default to OTG.
> +    $ref: /schemas/types.yaml#/definitions/string
> +    enum: [host, peripheral, otg]
> +
> +  phy_type:
> +    description:
> +      Tells USB controllers that we want to configure the core to support a
> +      UTMI+ PHY with an 8- or 16-bit interface if UTMI+ is selected. In case
> +      this isn't passed via DT, USB controllers should default to HW
> +      capability.
> +    $ref: /schemas/types.yaml#/definitions/string
> +    enum: [utmi, utmi_wide]
> +
> +  otg-rev:
> +    description:
> +      Tells usb driver the release number of the OTG and EH supplement with
> +      which the device and its descriptors are compliant, in binary-coded
> +      decimal (i.e. 2.0 is 0200H). This property is used if any real OTG
> +      features (HNP/SRP/ADP) is enabled. If ADP is required, otg-rev should be
> +      0x0200 or above.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  companion:
> +    description: Phandle of a companion device
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +
> +  hnp-disable:
> +    description:
> +      Tells OTG controllers we want to disable OTG HNP. Normally HNP is the
> +      basic function of real OTG except you want it to be a srp-capable only B
> +      device.
> +    type: boolean
> +
> +  srp-disable:
> +    description:
> +      Tells OTG controllers we want to disable OTG SRP. SRP is optional for OTG
> +      device.
> +    type: boolean
> +
> +  adp-disable:
> +    description:
> +      Tells OTG controllers we want to disable OTG ADP. ADP is optional for OTG
> +      device.
> +    type: boolean
> +
> +  usb-role-switch:
> +    description:
> +      Indicates that the device is capable of assigning the USB data role
> +      (USB host or USB device) for a given USB connector, such as Type-C,
> +      Type-B(micro). See connector/usb-connector.yaml.
> +
> +  role-switch-default-mode:
> +    description:
> +      Indicates if usb-role-switch is enabled, the device default operation
> +      mode of controller while usb role is USB_ROLE_NONE.
> +    $ref: /schemas/types.yaml#/definitions/string
> +    enum: [host, peripheral]
> +    default: peripheral
> +
>  examples:
>    - |
>      usb {
>          phys = <&usb2_phy1>, <&usb3_phy1>;
>          phy-names = "usb";
>      };
> +  - |
> +    usb@4a030000 {
> +        compatible = "snps,dwc3";
> +        reg = <0x4a030000 0xcfff>;
> +        interrupts = <0 92 4>;
> +        usb-phy = <&usb2_phy>, <&usb3_phy>;
> +        maximum-speed = "super-speed";
> +        dr_mode = "otg";
> +        phy_type = "utmi_wide";
> +        otg-rev = <0x0200>;
> +        adp-disable;
> +    };