Re: [PATCH v2 4/5] dt-bindings: PCI: spacemit: Introduce Spacemit K3 PCIe host controller

[Inochi Amaoto <inochiama@gmail.com>]

On Tue, Jun 09, 2026 at 11:11:20AM -0500, Alex Elder wrote:
> On 6/9/26 9:03 AM, Manivannan Sadhasivam wrote:
> > On Sun, May 17, 2026 at 09:48:39AM +0800, Inochi Amaoto wrote:
> > > Add binding support for the PCIe controller on the SpacemiT K3 SoC.
> > > This controller is almost a standard Synopsys DesignWare PCIe IP,
> > > with some extra link and reset state control.
> > > 
> > > Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
> > 
> > Why can't you reuse the existing spacemit,k1-pcie-host.yaml binding? I see very
> > few differences which could be added using conditionals. Also, this binding
> > defines the PHY property in the controller node, which is a way backwards as we
> > now prefer to define these in Root Port node as spacemit,k1-pcie-host.yaml does.
> 
> I agree.  I have another couple of comments below, including several
> things that just point out what's the same and what's different.
> 
> 					-Alex
> 

A good caught, I have confirmed, they share the same topology so it can
be reused.

Regards,
Inochi

> > 
> > - Mani
> > 
> > > ---
> > >   .../bindings/pci/spacemit,k3-pcie-host.yaml   | 135 ++++++++++++++++++
> > >   1 file changed, 135 insertions(+)
> > >   create mode 100644 Documentation/devicetree/bindings/pci/spacemit,k3-pcie-host.yaml
> > > 
> > > diff --git a/Documentation/devicetree/bindings/pci/spacemit,k3-pcie-host.yaml b/Documentation/devicetree/bindings/pci/spacemit,k3-pcie-host.yaml
> > > new file mode 100644
> > > index 000000000000..46147a37a9ce
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/pci/spacemit,k3-pcie-host.yaml
> > > @@ -0,0 +1,135 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/pci/spacemit,k3-pcie-host.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: SpacemiT K3 PCI Express Host Controller
> > > +
> > > +maintainers:
> > > +  - Inochi Amaoto <inochiama@gmail.com>
> 
> If you would like to maintain the (common) SpacemiT K1 host
> controller binding I'd be OK with that.
> 
> > > +
> > > +description:
> > > +  The SpacemiT K3 SoC PCIe host controller is based on the Synopsys
> > > +  DesignWare PCIe IP. The controller uses the external MSI interrupt
> > > +  controller.
> > > +
> > > +allOf:
> > > +  - $ref: /schemas/pci/pci-host-bridge.yaml#
> > > +  - $ref: /schemas/pci/snps,dw-pcie.yaml#
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: spacemit,k3-pcie
> > > +
> > > +  reg:
> > > +    items:
> > > +      - description: DesignWare PCIe registers
> > > +      - description: Data Bus Interface (DBI) shadow registers
> 
> The above is new (different from K1), as is "dbi2" as its name.
> 
> > > +      - description: ATU address space
> > > +      - description: PCIe configuration space
> > > +      - description: Link control registers
> > > +
> > > +  reg-names:
> > > +    items:
> > > +      - const: dbi
> > > +      - const: dbi2
> > > +      - const: atu
> > > +      - const: config
> > > +      - const: link
> > > +
> > > +  clocks:
> 
> Clocks and resets are the same as K1.
> 
> > > +    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
> > > +
> > > +  reset-names:
> > > +    items:
> > > +      - const: dbi
> > > +      - const: mstr
> > > +      - const: slv
> > > +
> > > +  msi-parent: true
> 
> msi-parent and phys are not present in the K1 binding.
> 
> > > +
> > > +  phys:
> > > +    description:
> > > +      PHY phandle from the Combo PHY, the lane number does not depends
> > > +      on this, since the number of lanes provided by Combo PHY can be
> > > +      1 or 2.
> > > +    minItems: 1
> > > +    maxItems: 6
> > > +
> > > +  phy-names:
> > > +    minItems: 1
> > > +    maxItems: 6
> > > +
> 
> The following property is the same as K1.
> 
> > > +  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
> > > +
> > > +required:
> > > +  - clocks
> > > +  - clock-names
> > > +  - resets
> > > +  - reset-names
> > > +  - msi-parent
> > > +  - spacemit,apmu
> > > +
> > > +unevaluatedProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/interrupt-controller/irq.h>
> > > +
> > > +    soc {
> > > +      #address-cells = <2>;
> > > +      #size-cells = <2>;
> > > +
> > > +      pcie@80000000 {
> > > +        compatible = "spacemit,k3-pcie";
> > > +        reg = <0x0  0x80000000 0x0 0x00001000>,
> > > +              <0x0  0x80100000 0x0 0x00001000>,
> > > +              <0x0  0x80300000 0x0 0x00003f20>,
> > > +              <0x11 0x00000000 0x0 0x00010000>,
> > > +              <0x0  0x82900000 0x0 0x00001000>;
> > > +        reg-names = "dbi", "dbi2", "atu", "config", "link";
> > > +        device_type = "pci";
> > > +        #address-cells = <3>;
> > > +        #size-cells = <2>;
> > > +        clocks = <&syscon_apmu 89>,
> > > +                 <&syscon_apmu 56>,
> > > +                 <&syscon_apmu 57>;
> > > +        clock-names = "dbi", "mstr", "slv";
> > > +        msi-parent = <&simsic>;
> > > +        ranges = <0x01000000 0x00 0x00010000 0x11 0x00010000 0x0 0x00100000>,
> > > +                 <0x02000000 0x0  0x00110000 0x11 0x00110000 0x0 0x7fef0000>,
> > > +                 <0x43000000 0x18 0x00000000 0x18 0x00000000 0x1 0x00000000>;
> > > +        resets = <&syscon_apmu 76>,
> > > +                 <&syscon_apmu 78>,
> > > +                 <&syscon_apmu 77>;
> > > +        reset-names = "dbi", "mstr", "slv";
> > > +        linux,pci-domain = <0>;
> > > +        spacemit,apmu = <&syscon_apmu 0x1f0>;
> > > +      };
> > > +    };
> > > +
> > > -- 
> > > 2.54.0
> > > 
> > 
>