Re: [PATCH v3 4/9] dt-bindings: PCI: renesas,r9a08g045s33-pcie: Add documentation for the PCIe IP on Renesas RZ/G3S

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Aug 28, 2025 at 10:11:55PM +0300, claudiu beznea wrote:
> On 8/8/25 14:25, Claudiu Beznea wrote:
> > On 08.07.2025 19:34, Bjorn Helgaas wrote:
> > > On Fri, Jul 04, 2025 at 07:14:04PM +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.
> ...

> Renesas HW team replied to me that there are no clock, reset, or interrupt
> signals dedicated specifically to the Root Port. All these signals are
> shared across the PCIe system.
> 
> Taking this and your suggestions into account, I have prepared the following
> device tree:
> 
> pcie: pcie@11e40000 {
> 	compatible = "renesas,r9a08g045-pcie";
> 	reg = <0 0x11e40000 0 0x10000>;
> 	ranges = <0x02000000 0 0x30000000 0 0x30000000 0 0x8000000>;
> 	/* Map all possible DRAM ranges (4 GB). */
> 	dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0x1 0x0>;
> 	bus-range = <0x0 0xff>;
> 	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 = "serr", "serr_cor", "serr_nonfatal",
> 			  "serr_fatal", "axi_err", "inta",
> 			  "intb", "intc", "intd", "msi",
> 			  "link_bandwidth", "pm_pme", "dma",
> 			  "pcie_evt", "msg", "all";
> 	#interrupt-cells = <1>;
> 	interrupt-controller;
> 	interrupt-map-mask = <0 0 0 7>;
> 	interrupt-map = <0 0 0 1 &pcie 0 0 0 0>, /* INTA */
> 			<0 0 0 2 &pcie 0 0 0 1>, /* INTB */
> 			<0 0 0 3 &pcie 0 0 0 2>, /* INTC */
> 			<0 0 0 4 &pcie 0 0 0 3>; /* INTD */
> 	clocks = <&cpg CPG_MOD R9A08G045_PCI_ACLK>,
> 		 <&cpg CPG_MOD R9A08G045_PCI_CLKL1PM>;
> 	clock-names = "aclk", "pm";
> 	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";
> 	power-domains = <&cpg>;
> 	device_type = "pci";
> 	#address-cells = <3>;
> 	#size-cells = <2>;
> 	renesas,sysc = <&sysc>;
> 	status = "disabled";
> 
> 	pcie_port0: pcie@0,0 {
> 		reg = <0x0 0x0 0x0 0x0 0x0>;
> 		ranges;
> 		clocks = <&versa3 5>;
> 		clock-names = "ref";
> 		device_type = "pci";
> 		vendor-id = <0x1912>;
> 		device-id = <0x0033>;
> 		bus-range = <0x1 0xff>;

I don't think you need this bus-range.  The bus range for the
hierarchy below a Root Port is discoverable and configurable via
config space.

> 		#address-cells = <3>;
> 		#size-cells = <2>;
> 	};
> };