Re: [PATCH 4/8] dt-bindings: PCI: renesas,r9a08g045s33-pcie: Add documentation for the PCIe IP on Renesas RZ/G3S

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Apr 30, 2025 at 01:32:32PM +0300, Claudiu wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> The PCIe IP available on the Renesas RZ/G3S complies with the PCI Express
> Base Specification 4.0. It is designed for root complex applications and
> features a single-lane (x1) implementation. Add documentation for it.
> The interrupts, interrupt-names, resets, reset-names, clocks, clock-names
> description were obtained from the hardware manual.

> +        pcie@11e40000 {
> +            compatible = "renesas,r9a08g045s33-pcie";
> +            reg = <0 0x11e40000 0 0x10000>;
> +            ranges = <0x03000000 0 0x30000000 0 0x30000000 0 0x8000000>;
> +            dma-ranges = <0x42000000 0 0x48000000 0 0x48000000 0 0x8000000>;
> +            bus-range = <0x0 0xff>;
> +            clocks = <&cpg CPG_MOD R9A08G045_PCI_ACLK>,
> +                     <&cpg CPG_MOD R9A08G045_PCI_CLKL1PM>;
> +            clock-names = "aclk", "clkl1pm";
> +            resets = <&cpg R9A08G045_PCI_ARESETN>,
> +                     <&cpg R9A08G045_PCI_RST_B>,
> +                     <&cpg R9A08G045_PCI_RST_GP_B>,
> +                     <&cpg R9A08G045_PCI_RST_PS_B>,
> +                     <&cpg R9A08G045_PCI_RST_RSM_B>,
> +                     <&cpg R9A08G045_PCI_RST_CFG_B>,
> +                     <&cpg R9A08G045_PCI_RST_LOAD_B>;
> +            reset-names = "aresetn", "rst_b", "rst_gp_b", "rst_ps_b",
> +                          "rst_rsm_b", "rst_cfg_b", "rst_load_b";

Could this be structured in a way that separates the shared Root
Complex properties from the ones that are specific to the Root Port?
I know the current hardware only supports a single Root Port, but I
think we should plan to be able to support multiple Root Ports.

> +            interrupts = <GIC_SPI 395 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 396 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 397 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 398 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 399 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 400 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 401 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 402 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 403 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 404 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 405 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 406 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 407 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 408 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 409 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 410 IRQ_TYPE_LEVEL_HIGH>;
> +            interrupt-names = "int_serr", "int_serr_cor", "int_serr_nonfatal",
> +                              "int_serr_fatal", "axi_err_int", "inta_rc",
> +                              "intb_rc", "intc_rc", "intd_rc",
> +                              "intmsi_rc", "int_link_bandwidth", "int_pm_pme",
> +                              "dma_int", "pcie_evt_int", "msg_int",
> +                              "int_all";
> +            #interrupt-cells = <1>;
> +            interrupt-map-mask = <0 0 0 7>;
> +            interrupt-map = <0 0 0 1 &pcie_intx 0>, /* INT A */
> +                            <0 0 0 2 &pcie_intx 1>, /* INT B */
> +                            <0 0 0 3 &pcie_intx 2>, /* INT C */
> +                            <0 0 0 4 &pcie_intx 3>; /* INT D */
> +            device_type = "pci";
> +            num-lanes = <1>;
> +            #address-cells = <3>;
> +            #size-cells = <2>;
> +            power-domains = <&cpg>;
> +            renesas,sysc = <&sysc>;
> +            vendor-id = <0x1912>;
> +            device-id = <0x0033>;
> +
> +            pcie_intx: legacy-interrupt-controller {
> +                interrupt-controller;
> +                #interrupt-cells = <1>;
> +                #address-cells = <0>;
> +                interrupt-parent = <&gic>;
> +                interrupts = <GIC_SPI 400 IRQ_TYPE_LEVEL_HIGH>,
> +                             <GIC_SPI 401 IRQ_TYPE_LEVEL_HIGH>,
> +                             <GIC_SPI 402 IRQ_TYPE_LEVEL_HIGH>,
> +                             <GIC_SPI 403 IRQ_TYPE_LEVEL_HIGH>;
> +            };
> +        };
> +    };
> +
> +...
> -- 
> 2.43.0
>