Aw: Re: [RFC/RFT 1/6] dt-bindings: phy: rockchip: add pcie3 phy

[Frank Wunderlich]

> Gesendet: Montag, 18. April 2022 um 17:52 Uhr
> Von: "Krzysztof Kozlowski" <krzysztof.kozlowski at linaro.org>
> > diff --git a/Documentation/devicetree/bindings/phy/rockchip-pcie3-phy.yaml b/Documentation/devicetree/bindings/phy/rockchip-pcie3-phy.yaml
> > new file mode 100644
> > index 000000000000..58a8ce175f13
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/rockchip-pcie3-phy.yaml
>
> Filename: vendor,hardware
> so for example "rockchip,pcie3-phy" although Rob proposed recently for
> other bindings using compatible as a base:
> https://lore.kernel.org/linux-devicetree/YlhkwvGdcf4ozTzG@robh.at.kernel.org/

ok, i rename

> > @@ -0,0 +1,77 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/phy/rockchip-pcie3-phy.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Rockchip PCIe v3 phy
> > +
> > +maintainers:
> > +  - Heiko Stuebner <heiko at sntech.de>
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - rockchip,rk3568-pcie3-phy
> > +      - rockchip,rk3588-pcie3-phy
> > +
> > +  reg:
> > +    maxItems: 2
> > +
> > +  clocks:
> > +    minItems: 1
> > +    maxItems: 3
> > +
> > +  clock-names:
> > +    contains:
> > +      anyOf:
> > +        - enum: [ refclk_m, refclk_n, pclk ]
>
> The list should be strictly ordered (defined), so:
>   items:
>     - const: ...
>     - const: ...
>     - const: ...
>   minItems: 1
>
> However the question is - why the clocks have different amount? Is it
> per different SoC implementation?

i only know the rk3568, which needs the clocks defined here, don't know about rk3588 yet.
in rk3568 TPM i have the pcie-part seems missing (at least the specific register definition), so i had used the driver as i got it from the downstream kernel.

not yet looked if i find a rk3588 TPM and if this part is there as i cannot test it (one of the reasons this is a rfc/rft).

> > +
> > +  "#phy-cells":
> > +    const: 0
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  reset-names:
> > +    const: phy
> > +
> > +  rockchip,phy-grf:
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> > +    description: phandle to the syscon managing the phy "general register files"
> > +
> > +  rockchip,pipe-grf:
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> > +    description: phandle to the syscon managing the pipe "general register files"
> > +
> > +  rockchip,pcie30-phymode:
> > +    $ref: '/schemas/types.yaml#/definitions/uint32'
> > +    description: |
> > +      use PHY_MODE_PCIE_AGGREGATION if not defined
>
> I don't understand the description. Do you mean here a case when the
> variable is missing?

yes, if the property is not set, then value is PHY_MODE_PCIE_AGGREGATION = 4

> > +    minimum: 0x0
> > +    maximum: 0x4
>
> Please explain these values. Register values should not be part of
> bindings, but instead some logical behavior of hardware or its logic.

it's a bitmask, so maybe

    description: |
      bit0: bifurcation for port 0
      bit1: bifurcation for port 1
      bit2: aggregation
      use PHY_MODE_PCIE_AGGREGATION (4) as default

> > +
> > +
>
> Just one blank line.
>
> > +required:
> > +  - compatible
> > +  - reg
> > +  - rockchip,phy-grf
>
> phy-cells as well
>
> > +
> > +additionalProperties: false
> > +
> > +unevaluatedProperties: false
>
> Just one please, additionalProperties.
ok

> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/rk3568-cru.h>
> > +    pcie30phy: phy at fe8c0000 {
> > +      compatible = "rockchip,rk3568-pcie3-phy";
> > +      reg = <0x0 0xfe8c0000 0x0 0x20000>;
> > +      #phy-cells = <0>;
> > +      clocks = <&pmucru CLK_PCIE30PHY_REF_M>, <&pmucru CLK_PCIE30PHY_REF_N>,
> > +       <&cru PCLK_PCIE30PHY>;
>
> Align the entry with opening '<'. Usually the most readable is one clock
> per line.

ok

> > +      clock-names = "refclk_m", "refclk_n", "pclk";
> > +      resets = <&cru SRST_PCIE30PHY>;
> > +      reset-names = "phy";
> > +      rockchip,phy-grf = <&pcie30_phy_grf>;
> > +    };

regards Frank