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

[Claudiu Beznea <claudiu.beznea@tuxon.dev>]

Hi, Bjorn,

On 01.05.2025 23:16, Bjorn Helgaas wrote:
> 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.

I'm not sure how should I do this. These are just the reset signals as the
manual describes them. Can you, please, point me an example driver/device
tree that I could check?

Thank you for your review,
Claudiu

> 
>> +            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
>>