[PATCH v2 3/7] dt-bindings: pci: spacemit: introduce PCIe host controller

[Manivannan Sadhasivam]

On Mon, Oct 13, 2025 at 10:35:20AM -0500, Alex Elder wrote:
> Add the Device Tree binding for the PCIe root complex found on the
> SpacemiT K1 SoC.  This device is derived from the Synopsys Designware
> PCIe IP.  It supports up to three PCIe ports operating at PCIe gen 2
> link speeds (5 GT/sec).  One of the ports uses a combo PHY, which is
> typically used to support a USB 3 port.
> 
> Signed-off-by: Alex Elder <elder at riscstar.com>
> ---
> v2: - Renamed the binding, using "host controller"
>     - Added '>' to the description, and reworded it a bit
>     - Added reference to /schemas/pci/snps,dw-pcie.yaml
>     - Fixed and renamed the compatible string
>     - Renamed the PMU property, and fixed its description
>     - Consistently omit the period at the end of descriptions
>     - Renamed the "global" clock to be "phy"
>     - Use interrupts rather than interrupts-extended, and name the
>       one interrupt "msi" to make clear its purpose
>     - Added a vpcie3v3-supply property
>     - Dropped the max-link-speed property
>     - Changed additionalProperties to unevaluatedProperties
>     - Dropped the label and status property from the example
> 
>  .../bindings/pci/spacemit,k1-pcie-host.yaml   | 156 ++++++++++++++++++
>  1 file changed, 156 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/spacemit,k1-pcie-host.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pci/spacemit,k1-pcie-host.yaml b/Documentation/devicetree/bindings/pci/spacemit,k1-pcie-host.yaml
> new file mode 100644
> index 0000000000000..87745d49c53a1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/spacemit,k1-pcie-host.yaml
> @@ -0,0 +1,156 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/spacemit,k1-pcie-host.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: SpacemiT K1 PCI Express Host Controller
> +
> +maintainers:
> +  - Alex Elder <elder at riscstar.com>
> +
> +description: >
> +  The SpacemiT K1 SoC PCIe host controller is based on the Synopsys
> +  DesignWare PCIe IP.  The controller uses the DesignWare built-in
> +  MSI interrupt controller, and supports 256 MSIs.
> +
> +allOf:
> +  - $ref: /schemas/pci/snps,dw-pcie.yaml#
> +
> +properties:
> +  compatible:
> +    const: spacemit,k1-pcie
> +
> +  reg:
> +    items:
> +      - description: DesignWare PCIe registers
> +      - description: ATU address space
> +      - description: PCIe configuration space
> +      - description: Link control registers
> +
> +  reg-names:
> +    items:
> +      - const: dbi
> +      - const: atu
> +      - const: config
> +      - const: link
> +
> +  spacemit,apmu:
> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> +    description:
> +      A phandle that refers to the APMU system controller, whose
> +      regmap is used in managing resets and link state, along with
> +      and offset of its reset control register.
> +    items:
> +      - items:
> +          - description: phandle to APMU system controller
> +          - description: register offset
> +
> +  clocks:
> +    items:
> +      - description: DWC PCIe Data Bus Interface (DBI) clock
> +      - description: DWC PCIe application AXI-bus master interface clock
> +      - description: DWC PCIe application AXI-bus slave interface clock
> +
> +  clock-names:
> +    items:
> +      - const: dbi
> +      - const: mstr
> +      - const: slv
> +
> +  resets:
> +    items:
> +      - description: DWC PCIe Data Bus Interface (DBI) reset
> +      - description: DWC PCIe application AXI-bus master interface reset
> +      - description: DWC PCIe application AXI-bus slave interface reset
> +      - description: Global reset; must be deasserted for PHY to function
> +
> +  reset-names:
> +    items:
> +      - const: dbi
> +      - const: mstr
> +      - const: slv
> +      - const: phy
> +
> +  interrupts:
> +    items:
> +      - description: Interrupt used for MSIs
> +
> +  interrupt-names:
> +    const: msi
> +
> +  phys:
> +    maxItems: 1
> +
> +  vpcie3v3-supply:
> +    description:
> +      A phandle for 3.3v regulator to use for PCIe

Could you please move these Root Port specific properties (phy, vpcie3v3-supply)
to the Root Port node?

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/pci/st,stm32-pcie-host.yaml

For handling the 'vpcie3v3-supply', you can rely on PCI_PWRCTRL_SLOT driver.

> +
> +  device_type:
> +    const: pci
> +

This is part of the PCI bus schema itself.

> +  num-viewport:
> +    const: 8
> +

This property has been deprecated in favor of driver auto-detecting the iATU
regions.

- Mani

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