Re: [PATCH v3 1/2] dt-bindings: PCI: intel: Add YAML schemas for the PCIe RC controller

[Dilip Kota]

On 9/18/2019 2:40 AM, Rob Herring wrote:
> On Wed, Sep 04, 2019 at 06:10:30PM +0800, Dilip Kota wrote:
> > The Intel PCIe RC controller is Synopsys Designware
> > based PCIe core. Add YAML schemas for PCIe in RC mode
> > present in Intel Universal Gateway soc.
> >
> > Signed-off-by: Dilip Kota <eswara.kota@xxxxxxxxxxxxxxx>
> > ---
> > changes on v3:
> > 	Add the appropriate License-Identifier
> > 	Rename intel,rst-interval to 'reset-assert-us'
> > 	Add additionalProperties: false
> > 	Rename phy-names to 'pciephy'
> > 	Remove the dtsi node split of SoC and board in the example
> > 	Add #interrupt-cells = <1>; or else interrupt parsing will fail
> > 	Name yaml file with compatible name
> >
> >   .../devicetree/bindings/pci/intel,lgm-pcie.yaml    | 137 +++++++++++++++++++++
> >   1 file changed, 137 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/pci/intel,lgm-pcie.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/pci/intel,lgm-pcie.yaml b/Documentation/devicetree/bindings/pci/intel,lgm-pcie.yaml
> > new file mode 100644
> > index 000000000000..5e5cc7fd66cd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pci/intel,lgm-pcie.yaml
> > @@ -0,0 +1,137 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pci/intel-pcie.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Intel AXI bus based PCI express root complex
> > +
> > +maintainers:
> > +  - Dilip Kota <eswara.kota@xxxxxxxxxxxxxxx>
> > +
> > +properties:
> > +  compatible:
> > +    const: intel,lgm-pcie
> > +
> > +  device_type:
> > +    const: pci
> > +
> > +  "#address-cells":
> > +    const: 3
> > +
> > +  "#size-cells":
> > +    const: 2
> These all belong in a common schema.
>
> > +
> > +  reg:
> > +    items:
> > +      - description: Controller control and status registers.
> > +      - description: PCIe configuration registers.
> > +      - description: Controller application registers.
> > +
> > +  reg-names:
> > +    items:
> > +      - const: dbi
> > +      - const: config
> > +      - const: app
> > +
> > +  ranges:
> > +    description: Ranges for the PCI memory and I/O regions.
> And this.
>
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    description: PCIe registers interface clock.
> > +
> > +  phys:
> > +    maxItems: 1
> > +
> > +  phy-names:
> > +    const: pciephy
> > +
> > +  reset-gpios:
> > +    maxItems: 1
> > +
> > +  num-lanes:
> > +    description: Number of lanes to use for this port.
> > +
> > +  linux,pci-domain:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: PCI domain ID.
> These 2 also should be common.
>
> > +
> > +  interrupts:
> > +    description: PCIe core integrated miscellaneous interrupt.
> How many? No need for description if there's only 1.
>
> > +
> > +  '#interrupt-cells':
> > +    const: 1
> > +
> > +  interrupt-map-mask:
> > +    description: Standard PCI IRQ mapping properties.
> > +
> > +  interrupt-map:
> > +    description: Standard PCI IRQ mapping properties.
> > +
> > +  max-link-speed:
> > +    description: Specify PCI Gen for link capability.
> > +
> > +  bus-range:
> > +    description: Range of bus numbers associated with this controller.
> All common.
You mean to remove all the common schema entries description!.
In most of the Documention/devicetree/binding/pci documents all the 
common entries are described so I followed the same.
> > +
> > +  reset-assert-ms:
> > +    description: |
> > +      Device reset interval in ms.
> > +      Some devices need an interval upto 500ms. By default it is 100ms.
> This is a property of a device, so it belongs in a device node. How
> would you deal with this without DT?
This property is for the PCIe RC to keep a delay before notifying the 
reset to the device.
If this entry is not present, PCIe driver will set a default value of 100ms.
> > +
> > +required:
> > +  - compatible
> > +  - device_type
> > +  - reg
> > +  - reg-names
> > +  - ranges
> > +  - resets
> > +  - clocks
> > +  - phys
> > +  - phy-names
> > +  - reset-gpios
> > +  - num-lanes
> > +  - linux,pci-domain
> > +  - interrupts
> > +  - interrupt-map
> > +  - interrupt-map-mask
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    pcie10:pcie@d0e00000 {
> > +      compatible = "intel,lgm-pcie";
> > +      device_type = "pci";
> > +      #address-cells = <3>;
> > +      #size-cells = <2>;
> > +      reg = <
> > +            0xd0e00000 0x1000
> > +            0xd2000000 0x800000
> > +            0xd0a41000 0x1000
> > +            >;
> > +      reg-names = "dbi", "config", "app";
> > +      linux,pci-domain = <0>;
> > +      max-link-speed = <4>;
> > +      bus-range = <0x00 0x08>;
> > +      interrupt-parent = <&ioapic1>;
> > +      interrupts = <67 1>;
> > +      #interrupt-cells = <1>;
> > +      interrupt-map-mask = <0 0 0 0x7>;
> > +      interrupt-map = <0 0 0 1 &ioapic1 27 1>,
> > +                      <0 0 0 2 &ioapic1 28 1>,
> > +                      <0 0 0 3 &ioapic1 29 1>,
> > +                      <0 0 0 4 &ioapic1 30 1>;
> > +      ranges = <0x02000000 0 0xd4000000 0xd4000000 0 0x04000000>;
> > +      resets = <&rcu0 0x50 0>;
> > +      clocks = <&cgu0 LGM_GCLK_PCIE10>;
> > +      phys = <&cb0phy0>;
> > +      phy-names = "pciephy";
> > +      status = "okay";
> > +      reset-assert-ms = <500>;
> > +      reset-gpios = <&gpio0 3 GPIO_ACTIVE_LOW>;
> > +      num-lanes = <2>;
> > +    };
> > --
> > 2.11.0