Re: [PATCH v2 1/2] dt-bindings: PCI: cadence: Add PCIe RC/EP DT schema for Cadence PCIe

[Rob Herring <robh@kernel.org>]

On Mon, Feb 17, 2020 at 04:45:18PM +0530, Kishon Vijay Abraham I wrote:
> Add PCIe Host (RC) and Endpoint (EP) device tree schema for Cadence
> PCIe core library. Platforms using Cadence PCIe core can include the
> schemas added here in the platform specific schemas.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  .../devicetree/bindings/pci/cdns-pcie-ep.yaml | 22 +++++++++
>  .../bindings/pci/cdns-pcie-host.yaml          | 27 +++++++++++
>  .../devicetree/bindings/pci/cdns-pcie.yaml    | 45 +++++++++++++++++++
>  3 files changed, 94 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml
>  create mode 100644 Documentation/devicetree/bindings/pci/cdns-pcie-host.yaml
>  create mode 100644 Documentation/devicetree/bindings/pci/cdns-pcie.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml
> new file mode 100644
> index 000000000000..b22d54605009
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml
> @@ -0,0 +1,22 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/pci/cdns-pcie-ep.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Cadence PCIe Endpoint
> +
> +maintainers:
> +  - Tom Joseph <tjoseph@cadence.com>
> +
> +allOf:
> +  - $ref: "cdns-pcie.yaml#"
> +
> +properties:
> +  max-functions:
> +    description: Maximum number of functions that can be configured
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint8
> +    minimum: 1
> +    default: 1
> +    maximum: 256

Create a pcie-ep.yaml and put this there as every endpoint binding 
seems to use this and I'm sure there's more properties to come. 

Also, the max can only be 255.

> diff --git a/Documentation/devicetree/bindings/pci/cdns-pcie-host.yaml b/Documentation/devicetree/bindings/pci/cdns-pcie-host.yaml
> new file mode 100644
> index 000000000000..ab6e43b636ec
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/cdns-pcie-host.yaml
> @@ -0,0 +1,27 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/pci/cdns-pcie-host.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Cadence PCIe Host
> +
> +maintainers:
> +  - Tom Joseph <tjoseph@cadence.com>
> +
> +allOf:
> +  - $ref: "/schemas/pci/pci-bus.yaml#"
> +  - $ref: "cdns-pcie.yaml#"
> +
> +properties:
> +  cdns,no-bar-match-nbits:
> +    description:
> +      Set into the no BAR match register to configure the number of least
> +      significant bits kept during inbound (PCIe -> AXI) address translations

This should probably be deprecated IMO. This info should really be 
extracted from sizes in 'dma-ranges'.

> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 0
> +    maximum: 64
> +    default: 32
> +
> +  msi-parent: true
> diff --git a/Documentation/devicetree/bindings/pci/cdns-pcie.yaml b/Documentation/devicetree/bindings/pci/cdns-pcie.yaml
> new file mode 100644
> index 000000000000..fd690b062de1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/cdns-pcie.yaml
> @@ -0,0 +1,45 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/pci/cdns-pcie.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Cadence PCIe Core
> +
> +maintainers:
> +  - Tom Joseph <tjoseph@cadence.com>
> +
> +properties:
> +  max-link-speed:
> +    description: maximum link speed
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 1
> +    maximum: 4

Standard property in pci-bus.yaml, no need to define it again.

> +
> +  num-lanes:
> +    description: maximum number of lanes
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 1
> +    maximum: 16

This should be added to pci-bus.yaml. Assume here it is.

> +
> +  cdns,max-outbound-regions:
> +    description: maximum number of outbound regions
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 1
> +    maximum: 32
> +    default: 32

This too should be deprecated IMO. It is nothing more than error 
checking number of 'ranges' entries. But deprecating should be a 
follow-up.

> +
> +  phys:
> +    description:
> +      One per lane if more than one in the list. If only one PHY listed it must
> +      manage all lanes.
> +    minItems: 1
> +    maxItems: 16
> +
> +  phy-names:
> +    items:
> +      - const: pcie-phy
> +    # FIXME: names when more than 1
> -- 
> 2.17.1
>