Re: [PATCH v7 2/5] dt-bindings: imx6q-pcie: Add schema for i.MX8M PCIe Endpoint modes

[Rob Herring <robh@kernel.org>]

On Mon, Jan 30, 2023 at 11:32:16AM +0800, Richard Zhu wrote:
> Add support for i.MX8M PCIe Endpoint modes, and update the MAINTAINER
> accordingly.
> 
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
>  .../bindings/pci/fsl,imx6q-pcie-ep.yaml       | 317 ++++++++++++++++++
>  MAINTAINERS                                   |   1 +
>  2 files changed, 318 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
> new file mode 100644
> index 000000000000..7c594ae53067
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
> @@ -0,0 +1,317 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/fsl,imx6q-pcie-ep.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale i.MX6 PCIe Endpoint controller
> +
> +maintainers:
> +  - Lucas Stach <l.stach@pengutronix.de>
> +  - Richard Zhu <hongxing.zhu@nxp.com>
> +
> +description: |+
> +  This PCIe controller is based on the Synopsys DesignWare PCIe IP and
> +  thus inherits all the common properties defined in snps,dw-pcie-ep.yaml.
> +  The controller instances are dual mode where in they can work either in
> +  Root Port mode or Endpoint mode but one at a time.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - fsl,imx8mm-pcie-ep
> +      - fsl,imx8mq-pcie-ep
> +      - fsl,imx8mp-pcie-ep
> +
> +  reg:
> +    minItems: 2
> +
> +  reg-names:
> +    items:
> +      - const: dbi
> +      - const: addr_space
> +
> +  interrupts:
> +    items:
> +      - description: builtin eDMA interrupter.
> +
> +  interrupt-names:
> +    items:
> +      - const: dma
> +
> +  clocks:
> +    minItems: 3
> +    items:
> +      - description: PCIe bridge clock.
> +      - description: PCIe bus clock.
> +      - description: PCIe PHY clock.
> +      - description: Additional required clock entry for imx6sx-pcie-ep,
> +          imx8mq-pcie-ep.
> +
> +  clock-names:
> +    minItems: 3
> +    items:
> +      - const: pcie
> +      - const: pcie_bus
> +      - enum: [ pcie_phy, pcie_aux ]
> +      - enum: [ pcie_inbound_axi, pcie_aux ]

Are the clocks in endpoint mode suddenly different? I can't tell, but 
will assume so since they added here.

> +
> +  num-lanes:
> +    const: 1

You shouldn't need this if it can only be 1 value.

> +
> +  fsl,imx7d-pcie-phy:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description: A phandle to an fsl,imx7d-pcie-phy node. Additional
> +      required properties for imx7d-pcie-ep and imx8mq-pcie-ep.
> +
> +  power-domains:
> +    minItems: 1
> +    items:
> +      - description: The phandle pointing to the DISPLAY domain for
> +          imx6sx-pcie-ep, to PCIE_PHY power domain for imx7d-pcie-ep and
> +          imx8mq-pcie-ep.
> +      - description: The phandle pointing to the PCIE_PHY power domains
> +          for imx6sx-pcie-ep.
> +
> +  power-domain-names:
> +    minItems: 1
> +    items:
> +      - const: pcie
> +      - const: pcie_phy
> +
> +  resets:
> +    minItems: 2
> +    maxItems: 3
> +    description: Phandles to PCIe-related reset lines exposed by SRC
> +      IP block. Additional required by imx7d-pcie-ep and imx8mq-pcie-ep.
> +
> +  reset-names:
> +    minItems: 2
> +    maxItems: 3

Same question for resets.

> +
> +  fsl,tx-deemph-gen1:
> +    description: Gen1 De-emphasis value (optional required).
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 0
> +
> +  fsl,tx-deemph-gen2-3p5db:
> +    description: Gen2 (3.5db) De-emphasis value (optional required).
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 0
> +
> +  fsl,tx-deemph-gen2-6db:
> +    description: Gen2 (6db) De-emphasis value (optional required).
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 20
> +
> +  fsl,tx-swing-full:
> +    description: Gen2 TX SWING FULL value (optional required).
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 127
> +
> +  fsl,tx-swing-low:
> +    description: TX launch amplitude swing_low value (optional required).
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 127

Now we'd duplicated defining the type for all these properties...

This needs to be restructured into a schema of all the common properties 
and then the host and endpoint schema can reference it. IOW, like how 
other schemas have been done.

Rob