Re: [PATCH v16 18/22] dt-bindings: PCI: renesas: Add R-Car Gen4 PCIe Endpoint

[Serge Semin <fancer.lancer@gmail.com>]

On Wed, May 10, 2023 at 03:22:30PM +0900, Yoshihiro Shimoda wrote:
> Document bindings for Renesas R-Car Gen4 and R-Car S4-8 (R8A779F0)
> PCIe endpoint module.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
> ---
>  .../bindings/pci/rcar-gen4-pci-ep.yaml        | 98 +++++++++++++++++++
>  1 file changed, 98 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/rcar-gen4-pci-ep.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pci/rcar-gen4-pci-ep.yaml b/Documentation/devicetree/bindings/pci/rcar-gen4-pci-ep.yaml
> new file mode 100644
> index 000000000000..0453bdcf9645
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/rcar-gen4-pci-ep.yaml
> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2022-2023 Renesas Electronics Corp.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/rcar-gen4-pci-ep.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Renesas R-Car Gen4 PCIe Endpoint
> +
> +maintainers:
> +  - Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> +
> +allOf:
> +  - $ref: snps,dw-pcie-ep.yaml#
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: renesas,r8a779f0-pcie-ep   # R-Car S4-8
> +      - const: renesas,rcar-gen4-pcie-ep  # R-Car Gen4
> +
> +  reg:
> +    maxItems: 6
> +
> +  reg-names:
> +    items:
> +      - const: dbi
> +      - const: dbi2
> +      - const: atu
> +      - const: dma
> +      - const: app
> +      - const: addr_space
> +
> +  interrupts:
> +    maxItems: 3
> +
> +  interrupt-names:
> +    items:
> +      - const: dma
> +      - const: sft_ce
> +      - const: app
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  max-functions:
> +    maximum: 2
> +
> +  max-link-speed:
> +    maximum: 4
> +
> +  num-lanes:
> +    maximum: 4
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - interrupts
> +  - resets
> +  - power-domains
> +  - clocks
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/r8a779f0-cpg-mssr.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/power/r8a779f0-sysc.h>
> +
> +    soc {
> +        #address-cells = <2>;
> +        #size-cells = <2>;
> +
> +        pcie0_ep: pcie-ep@e65d0000 {
> +            compatible = "renesas,r8a779f0-pcie-ep", "renesas,rcar-gen4-pcie-ep";

> +            reg = <0 0xe65d0000 0 0x2000>, <0 0xe65d2800 0 0x0800>,
> +                  <0 0xe65d3000 0 0x2000>, <0 0xe65d5000 0 0x1200>,
> +                  <0 0xe65d6200 0 0x0e00>, <0 0xfe000000 0 0x400000>;
> +            reg-names = "dbi", "dbi2", "atu", "dma", "app", "addr_space";

Just figured this out. I see you defining the dbi2 as <0 0xe65d2800 0
0x0800>. But sometime before you mentioned that your device has the
next CSRs layout:
! +0x0000 : Function 0 (common address in Root complex and Endpoint mode)
  +0x1000 : Function 1 (Endpoint mode only)
  +0x2000 : Shadow register for Function 0
! +0x2800 : Shadow register for Function 1
it means you have the dbi space defined for both functions meanwhile
the dbi2 space defined for _function #1_ only. Moreover
your DW PCIe End-point driver disables the multi-function feature
support. So AFAICS either you have wrong DW PCIe EP example node or
the node is wrong in your platform DTS too and you have a malfunction
end-point mode. Am I missing something? In any case based on the your
End-point driver implementation dbi2 is supposed to be defined at the
0xe65d2000 base address.

-Serge(y)

> +            interrupts = <GIC_SPI 417 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 418 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 422 IRQ_TYPE_LEVEL_HIGH>;
> +            interrupt-names = "dma", "sft_ce", "app";
> +            clocks = <&cpg CPG_MOD 624>;
> +            power-domains = <&sysc R8A779F0_PD_ALWAYS_ON>;
> +            resets = <&cpg 624>;
> +            num-lanes = <2>;
> +            max-link-speed = <4>;
> +        };
> +    };
> -- 
> 2.25.1
>