Re: 回覆: 回覆: [PATCH 5/7] ARM: dts: aspeed-g6: Add PCIe RC node

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jun 25, 2025 at 08:27:26AM +0000, Jacky Chou wrote:
> > > > > +				resets = <&syscon ASPEED_RESET_H2X>,
> > > > > +					 <&syscon ASPEED_RESET_PCIE_RC_O>;
> > > > > +				reset-names = "h2x", "perst";
> > > >
> > > > PERST# is clearly a per-Root Port item since it's a signal on the
> > > > PCIe connector.  Can you separate this and any other per-Root Port
> > > > things into a Root Port stanza to leave open the possibility of
> > > > future hardware that supports multiple Root Ports in the RC?
> > >
> > > The PCIe RC that designed by us is only one root port.
> > 
> > Yes.  But this driver may be used in the future for other RCs that include more
> > than one Root Port, and it would be good if that didn't require structural
> > changes to the DT.  Also, there are RCs from other vendors that include more
> > than one Root Port, and I'd like all the DTs and drivers to have similar
> > structure.
> 
> Thanks.
> Is the "pciec" node in arch/arm/boot/dts/marvell/armada-385.dtsi
> what you said?  Or could you provide some examples for us to modify
> our pcie rc node?

Here are some examples of DT bindings and corresponding driver code:

* drivers/pci/controller/dwc/pcie-kirin.c
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/pci/hisilicon,kirin-pcie.yaml?id=v6.16-rc1#n108

    kirin_pcie_parse_port():
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/dwc/pcie-kirin.c?id=v6.16-rc1#n399

* drivers/pci/controller/pci-mvebu.c
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/pci/marvell,kirkwood-pcie.yaml?id=v6.16-rc1#n125

    mvebu_pcie_parse_port():
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/pci-mvebu.c?id=v6.16-rc1#n1252

* drivers/pci/controller/pcie-mt7621.c
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/pci/mediatek,mt7621-pcie.yaml?id=v6.16-rc1#n111

    mt7621_pcie_parse_port():
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/pcie-mt7621.c.c?id=v6.16-rc1#n198

* drivers/pci/controller/pcie-mediatek.c
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/pci/mediatek-pcie.txt?id=v6.16-rc1#n85

    mtk_pcie_parse_port():
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/pcie-mediatek.c.c?id=v6.16-rc1#n909