[PATCH v3 03/10] dt-bindings: PCI: Add ASPEED PCIe RC support

Manivannan Sadhasivam mani at kernel.org
Fri Sep 5 15:21:12 AEST 2025


On Tue, Sep 02, 2025 at 04:12:21PM GMT, Rob Herring wrote:
> On Mon, Sep 01, 2025 at 01:59:15PM +0800, Jacky Chou wrote:
> > ASPEED AST2600 provides one PCIe RC for Gen2 and AST2700 provides three
> > PCIe RC for two Gen4 and one Gen2. All of these RCs have just one root
> > port to connect to PCIe device. And also have Mem, I/O access, legacy
> > interrupt and MSI.
> > 
> > Signed-off-by: Jacky Chou <jacky_chou at aspeedtech.com>
> > ---
> >  .../bindings/pci/aspeed,ast2600-pcie.yaml     | 179 ++++++++++++++++++
> >  1 file changed, 179 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pci/aspeed,ast2600-pcie.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/pci/aspeed,ast2600-pcie.yaml b/Documentation/devicetree/bindings/pci/aspeed,ast2600-pcie.yaml
> > new file mode 100644
> > index 000000000000..fe75bf2961c8
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pci/aspeed,ast2600-pcie.yaml
> > @@ -0,0 +1,179 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pci/aspeed,ast2600-pcie.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ASPEED PCIe Root Complex Controller
> > +
> > +maintainers:
> > +  - Jacky Chou <jacky_chou at aspeedtech.com>
> > +
> > +description:
> > +  The ASPEED PCIe Root Complex controller provides PCI Express Root Complex
> > +  functionality for ASPEED SoCs, such as the AST2600 and AST2700.
> > +  This controller enables connectivity to PCIe endpoint devices, supporting
> > +  memory and I/O windows, MSI and legacy interrupts, and integration with
> > +  the SoC's clock, reset, and pinctrl subsystems.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - aspeed,ast2600-pcie
> > +      - aspeed,ast2700-pcie
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  ranges:
> > +    minItems: 2
> > +    maxItems: 2
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +    description: IntX and MSI interrupt
> > +
> > +  resets:
> > +    items:
> > +      - description: PCIe controller reset
> > +
> > +  reset-names:
> > +    items:
> > +      - const: h2x
> > +
> > +  msi-parent: true
> > +
> > +  aspeed,ahbc:
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> > +    description:
> > +      Phandle to the ASPEED AHB Controller (AHBC) syscon node.
> > +      This reference is used by the PCIe controller to access
> > +      system-level configuration registers related to the AHB bus.
> > +      To enable AHB access for the PCIe controller.
> > +
> > +  aspeed,pciecfg:
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> > +    description:
> > +      Phandle to the ASPEED PCIe configuration syscon node.
> > +      This reference allows the PCIe controller to access
> > +      SoC-specific PCIe configuration registers. There are the others
> > +      functions such PCIe RC and PCIe EP will use this common register
> > +      to configure the SoC interfaces.
> > +

So these config registers are part of the PCIe domain? Is so, accessing them as
syscon is wrong. You should configure the registers directly from the RC and EP
controller drivers.

> > +  interrupt-controller:
> > +    description: Interrupt controller node for handling legacy PCI interrupts.

s/legacy PCI interrupts/INTx

> > +    type: object
> > +    properties:
> > +      '#address-cells':
> > +        const: 0
> > +      '#interrupt-cells':
> > +        const: 1
> > +      interrupt-controller: true
> > +
> > +    required:
> > +      - '#address-cells'
> > +      - '#interrupt-cells'
> > +      - interrupt-controller
> > +
> > +    additionalProperties: false
> > +
> > +allOf:
> > +  - $ref: /schemas/pci/pci-host-bridge.yaml#
> > +  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: aspeed,ast2600-pcie
> > +    then:
> > +      required:
> > +        - aspeed,ahbc
> > +    else:
> > +      properties:
> > +        aspeed,ahbc: false
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: aspeed,ast2700-pcie
> > +    then:
> > +      required:
> > +        - aspeed,pciecfg
> > +    else:
> > +      properties:
> > +        aspeed,pciecfg: false
> > +
> > +required:
> > +  - reg
> > +  - interrupts
> > +  - bus-range
> > +  - ranges
> > +  - resets
> > +  - reset-names
> > +  - msi-parent
> > +  - msi-controller
> > +  - interrupt-map-mask
> > +  - interrupt-map
> > +  - interrupt-controller
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/clock/ast2600-clock.h>
> > +
> > +    apb {
> > +      #address-cells = <1>;
> > +      #size-cells = <1>;
> 
> No need to show this node.
> 
> > +
> > +      pcie0: pcie at 1e770000 {
> > +        compatible = "aspeed,ast2600-pcie";
> > +        device_type = "pci";
> > +        reg = <0x1e770000 0x100>;
> > +        linux,pci-domain = <0>;
> > +        #address-cells = <3>;
> > +        #size-cells = <2>;
> > +        interrupts = <GIC_SPI 168 IRQ_TYPE_LEVEL_HIGH>;
> > +        bus-range = <0x80 0xff>;

Why bus number starts from 128?

> > +
> > +        ranges = <0x01000000 0x0 0x00018000 0x00018000 0x0 0x00008000
> > +            0x02000000 0x0 0x70000000 0x70000000 0x0 0x10000000>;
> > +
> > +        status = "disabled";
> 
> Examples should be enabled. Drop.
> 
> > +
> > +        resets = <&syscon ASPEED_RESET_H2X>;
> > +        reset-names = "h2x";
> > +
> > +        #interrupt-cells = <1>;
> > +        msi-parent = <&pcie0>;
> 
> There shouldn't be any need to point to yourself.
> 
> > +        msi-controller;
> > +
> > +        aspeed,ahbc = <&ahbc>;
> > +
> > +        interrupt-map-mask = <0 0 0 7>;
> > +        interrupt-map = <0 0 0 1 &pcie_intc0 0>,
> > +                        <0 0 0 2 &pcie_intc0 1>,
> > +                        <0 0 0 3 &pcie_intc0 2>,
> > +                        <0 0 0 4 &pcie_intc0 3>;
> > +        pcie_intc0: interrupt-controller {
> > +          interrupt-controller;
> > +          #address-cells = <0>;
> > +          #interrupt-cells = <1>;
> > +        };
> > +
> > +        pcie at 8,0 {
> > +          reg = <0x804000 0 0 0 0>;

Why the device number starts from 8?

If there are platform specific reasons behind this numbering scheme, it should
be mentioned in the description.

- Mani

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