Re: [PATCH 2/9] dt-bindings: phy: qcom,m31: Document qcom,m31 USB phy

[Varadarajan Narayanan]

On Wed, Jun 07, 2023 at 08:31:50PM +0200, Krzysztof Kozlowski wrote:
> On 07/06/2023 12:56, Varadarajan Narayanan wrote:
> > Document the M31 USB2 phy present in IPQ5332
>
> Full stop.

Ok.

> > Signed-off-by: Sricharan Ramabadhran <quic_srichara@xxxxxxxxxxx>
> > Signed-off-by: Varadarajan Narayanan <quic_varada@xxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/phy/qcom,m31.yaml          | 69 ++++++++++++++++++++++
> >  1 file changed, 69 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/phy/qcom,m31.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/phy/qcom,m31.yaml b/Documentation/devicetree/bindings/phy/qcom,m31.yaml
> > new file mode 100644
> > index 0000000..8ad4ba4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/qcom,m31.yaml
> > @@ -0,0 +1,69 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +
>
> Drop stray blank lines.

Ok.

> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/phy/qcom,m31.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Qualcomm M31 USB PHY
>
> What is M31?

M31 is an external IP integrated into IPQ5332 SoC.

> > +
> > +maintainers:
> > +  - Sricharan Ramabadhran <quic_srichara@xxxxxxxxxxx>
> > +  - Varadarajan Narayanan <quic_varada@xxxxxxxxxxx>
> > +
> > +description:
> > +  This file contains documentation for the USB M31 PHY found in Qualcomm
>
> Drop redundant parts ("This file contains documentation for the").

Ok.

> > +  IPQ5018, IPQ5332 SoCs.
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
>
> That's not oneOf.

Ok.

> > +      - items:
>
> No items.

Ok.

> > +          - enum:
> > +              - qcom,m31-usb-hsphy
>
> I am confused what's this. If m31 is coming from some IP block provider,
> then you are using wrong vendor prefix.
> https://www.m31tech.com/download_file/M31_USB.pdf
>
>
> > +              - qcom,ipq5332-m31-usb-hsphy
>
> This confuses me even more. IPQ m31?

Will change this to m31,usb-hsphy and m31,ipq5332-usb-hsphy respectively.
Will that be acceptable?

> > +
> > +  reg:
> > +    description:
> > +      Offset and length of the M31 PHY register set
>
> Drop description, obvious.

Ok.

> > +    maxItems: 2
> > +
> > +  reg-names:
> > +    items:
> > +      - const: m31usb_phy_base
> > +      - const: qscratch_base
>
> Drop "_base" from both.

Ok. Will drop qscratch_base. This is in the controller space.
Should not come here.

> > +
> > +  phy_type:
> > +    oneOf:
> > +      - items:
> > +          - enum:
> > +              - utmi
> > +              - ulpi
>
> This does not belong to phy, but to USB node.

This is used by the driver to set a bit during phy init. Hence
have it as a replication of the USB node's entry. If this is not
permissible, is there some way to get this from the USB node,
or any other alternative mechanism?

> > +
> > +  resets:
> > +    maxItems: 1
> > +    description:
> > +      List of phandles and reset pairs, one for each entry in reset-names.
>
> Drop useless description.

Ok.

> > +
> > +  reset-names:
> > +    items:
> > +      - const:
> > +          usb2_phy_reset
>
> Drop entire reset-names.

Ok.

> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/qcom,ipq5332-gcc.h>
> > +    hs_m31phy_0: hs_m31phy@5b00 {
>
> Node names should be generic. See also explanation and list of examples
> in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>
> Also, no underscores in node names.

Will change this as usbphy0:hs_m31phy@7b000

> > +        compatible = "qcom,m31-usb-hsphy";
> > +        reg = <0x5b000 0x3000>,
>
> This is not what your unit address is saying.

Will change to 0x0007b000.

> > +            <0x08af8800 0x400>;
>
> Align it.

Will drop this. This is in the controller space.

> > +        reg-names = "m31usb_phy_base",
> > +                "qscratch_base";
>
> Align it.

Ok.

> > +        phy_type = "utmi";
> > +        resets = <&gcc GCC_QUSB2_0_PHY_BCR>;
> > +        reset-names = "usb2_phy_reset";
> > +
> > +        status = "ok";
>
> Drop.

Ok. Hopefully will get an alternative for the phy_type.

Thanks
Varada

> > +    };
>
> Best regards,
> Krzysztof
>