Re: [PATCH 3/5] dt-bindings: net: Add Loongson-1 DWMAC glue layer

[Serge Semin]

Hi Keguang

On Sat, Aug 12, 2023 at 11:11:33PM +0800, Keguang Zhang wrote:
> Add devicetree binding document for Loongson-1 DWMAC glue layer.
> 
> Signed-off-by: Keguang Zhang <keguang.zhang@xxxxxxxxx>
> ---
>  .../bindings/net/loongson,ls1x-dwmac.yaml     | 98 +++++++++++++++++++
>  .../devicetree/bindings/net/snps,dwmac.yaml   |  2 +
>  2 files changed, 100 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/loongson,ls1x-dwmac.yaml
> 
> diff --git a/Documentation/devicetree/bindings/net/loongson,ls1x-dwmac.yaml b/Documentation/devicetree/bindings/net/loongson,ls1x-dwmac.yaml
> new file mode 100644
> index 000000000000..150799460599
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/loongson,ls1x-dwmac.yaml
> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/net/loongson,ls1x-dwmac.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +

> +title: Loongson-1 DWMAC glue layer

DT-schemas describe a device. It has nothing to do with the glue
driver/layer/whatever.

Also I suggest to add a brief device description in the
"description:" property and add there a brief info regarding the SoCs
the controllers can be found on, the DW (G)MAC IP-core version the
ethernet controllers are based on and if possible some data about the
synthesize parameters: SMA (MDIO-bus), Tx/Rx COE, DMA FIFOs size,
perfect and hash MAC-filters size, L3L4 frame filters availability,
PHY interfaces (MII, RMII, RGMII, etc), EEE support, IEEE 1588(-2008)
Timestamping support, PMT and Wake-up frame support, MAC Management
counters (MMC).

Note DMA FIFO sizes can be also constrained in the properties
"rx-fifo-depth" and "tx-fifo-depth"; perfect and hash MAC-filter sizes -
in "snps,perfect-filter-entries" and "snps,multicast-filter-bins".

> +
> +maintainers:
> +  - Keguang Zhang <keguang.zhang@xxxxxxxxx>
> +
> +select:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - loongson,ls1b-dwmac
> +          - loongson,ls1c-dwmac
> +  required:
> +    - compatible
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - loongson,ls1b-dwmac
> +          - loongson,ls1c-dwmac
> +      - const: snps,dwmac-3.50a
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    const: stmmaceth
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  interrupt-names:
> +    const: macirq
> +

> +  syscon:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      Phandle to the syscon containing some extra configurations
> +      including PHY interface mode.

I believe the property is supposed to have a vendor-specific name like
"loongson,ls1-syscon" or similar.

> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - interrupts
> +  - interrupt-names
> +  - phy-handle

> +  - phy-mode

You may want to specify the enum-constraints with the value permitted
for the particular Loongson (G)MAC controller. Seeing ls1b and ls1c
imply different sets of the PHY-modes the constraints are better to be
defined in the allOf sub-schemas. Alternatively you can split the
DT-schema file into two: one for ls1b-dwmac, another one for
ls1c-dwmac. IMO the later option seems better.

-Serge(y)

> +  - syscon
> +
> +allOf:
> +  - $ref: snps,dwmac.yaml#
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/loongson,ls1x-clk.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    gmac0: ethernet@1fe10000 {
> +        compatible = "loongson,ls1b-dwmac", "snps,dwmac-3.50a";
> +        reg = <0x1fe10000 0x10000>;
> +
> +        clocks = <&clkc LS1X_CLKID_AHB>;
> +        clock-names = "stmmaceth";
> +
> +        interrupt-parent = <&intc1>;
> +        interrupts = <2 IRQ_TYPE_LEVEL_HIGH>;
> +        interrupt-names = "macirq";
> +
> +        phy-handle = <&phy0>;
> +        phy-mode = "mii";
> +
> +        snps,pbl = <1>;
> +        syscon = <&syscon>;
> +
> +        mdio {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            compatible = "snps,dwmac-mdio";
> +
> +            phy0: ethernet-phy@0 {
> +                reg = <0x0>;
> +            };
> +        };
> +    };
> diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> index ddf9522a5dc2..e1a956cf171e 100644
> --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> @@ -66,6 +66,8 @@ properties:
>          - ingenic,x2000-mac
>          - loongson,ls2k-dwmac
>          - loongson,ls7a-dwmac
> +        - loongson,ls1b-dwmac
> +        - loongson,ls1c-dwmac
>          - qcom,qcs404-ethqos
>          - qcom,sa8775p-ethqos
>          - qcom,sc8280xp-ethqos
> -- 
> 2.39.2
>