Re: [v1,1/3] dt-bindings: Add YAML schemas for Gen3 PCIe controller

[Jianjun Wang <jianjun.wang@mediatek.com>]

On Tue, 2020-09-08 at 14:21 -0600, Rob Herring wrote:
> On Mon, Sep 07, 2020 at 08:08:50PM +0800, Jianjun Wang wrote:
> > Add YAML schemas documentation for Gen3 PCIe controller on
> > MediaTek SoCs.
> 
> dt-bindings: PCI: mediatek: ... for the subject.
> 
> > 
> > Acked-by: Ryder Lee <ryder.lee@mediatek.com>
> > Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> > ---
> >  .../bindings/pci/mediatek-pcie-gen3.yaml      | 158 ++++++++++++++++++
> >  1 file changed, 158 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > new file mode 100644
> > index 000000000000..108d29259c05
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> > @@ -0,0 +1,158 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pci/mediatek-pcie-gen3.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Gen3 PCIe controller on MediaTek SoCs
> > +
> > +maintainers:
> > +  - Jianjun Wang <jianjun.wang@mediatek.com>
> > +
> > +allOf:
> > +  - $ref: /schemas/pci/pci-bus.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - const: mediatek,gen3-pcie
> > +      - const: mediatek,mt8192-pcie
> > +
> 
> > +  device_type:
> > +    const: pci
> > +
> > +  "#address-cells":
> > +    const: 3
> > +
> > +  "#size-cells":
> > +    const: 2
> 
> Can drop these 3. Already in pci-bus.yaml.
> 
> > +
> > +  reg:
> > +    items:
> > +      - description: Controller control and status registers.
> 
> Just 'maxItems: 1'. The description doesn't add any value.
> 
> > +
> > +  reg-names:
> > +    items:
> > +      - const: pcie-mac
> 
> Don't really need a name here.
> 
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  bus-range:
> > +    description: Range of bus numbers associated with this controller.
> > +
> > +  ranges:
> > +    minItems: 1
> > +    maxItems: 8
> > +
> > +  resets:
> > +    minItems: 1
> > +    maxItems: 2
> > +
> > +  reset-names:
> > +    anyOf:
> > +      - const: mac-rst
> > +      - const: phy-rst
> 
> Doesn't the PHY's reset belong in the PHY node?

There are some cases that we don't need the PHY driver, but for the
reason of power saving, the HW still remain the PHY's reset in infra
domain and it will be asserted before kernel stage, so we still need to
release this reset in the PCIe MAC driver.
> 
> > +
> > +  clocks:
> > +    maxItems: 5
> > +
> > +  assigned-clocks:
> > +    maxItems: 1
> > +
> > +  assigned-clock-parents:
> > +    maxItems: 1
> > +
> > +  phys:
> > +    maxItems: 1
> > +
> > +  phy-names:
> > +    const: pcie-phy
> 
> Not really a useful name and there's only one. Please drop.
> 
> > +
> > +  '#interrupt-cells':
> > +    const: 1
> > +
> 
> > +  interrupt-map-mask:
> > +    description: Standard PCI IRQ mapping properties.
> > +
> > +  interrupt-map:
> > +    description: Standard PCI IRQ mapping properties.
> 
> Can drop these.
> 
> > +
> > +  legacy-interrupt-controller:
> 
> Just 'interrupt-controller'
> 
> And don't copy the same bug of using 'of_get_next_child'. You should get 
> the child node by name.
> 
> > +    description: Interrupt controller node for handling legacy PCI interrupts.
> > +    type: object
> > +    properties:
> > +      "#address-cells":
> > +        const: 0
> > +      "#interrupt-cells":
> > +        const: 1
> > +      interrupt-controller: true
> > +
> > +    required:
> > +      - "#address-cells"
> > +      - "#interrupt-cells"
> > +      - interrupt-controller
> 
>        additionalProperties: false
> 
> > +
> > +required:
> > +  - compatible
> 
> > +  - device_type
> > +  - "#address-cells"
> > +  - "#size-cells"
> 
> Don't need these, pci-bus.yaml already requires them.
> 
> > +  - reg
> > +  - reg-names
> > +  - bus-range
> 
> If the range is 0-0xff, then this isn't really required.
> 
> > +  - interrupts
> > +  - ranges
> > +  - clocks
> > +  - '#interrupt-cells'
> > +  - interrupt-map
> > +  - interrupt-map-mask
> > +  - legacy-interrupt-controller
> > +
> > +additionalProperties: false
> 
> unevaluatedProperties: false
> 
> (Should be used when including a ref (pci-bus.yaml).)
> 
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +
> > +    bus {
> > +        #address-cells = <2>;
> > +        #size-cells = <2>;
> > +
> > +        pcie: pcie@11230000 {
> > +            compatible = "mediatek,mt8192-pcie";
> > +            device_type = "pci";
> > +            #address-cells = <3>;
> > +            #size-cells = <2>;
> > +            reg = <0x00 0x11230000 0x00 0x4000>;
> > +            reg-names = "pcie-mac";
> > +            interrupts = <GIC_SPI 251 IRQ_TYPE_LEVEL_HIGH 0>;
> > +            bus-range = <0x00 0xff>;
> > +            ranges = <0x82000000 0x00 0x12000000 0x00 0x12000000 0x00 0x1000000>;
> > +            clocks = <&infracfg 40>,
> > +                     <&infracfg 43>,
> > +                     <&infracfg 97>,
> > +                     <&infracfg 99>,
> > +                     <&infracfg 111>;
> > +            assigned-clocks = <&topckgen 50>;
> > +            assigned-clock-parents = <&topckgen 91>;
> > +
> > +            phys = <&pciephy>;
> > +            phy-names = "pcie-phy";
> > +            resets = <&infracfg_rst 0>;
> > +            reset-names = "phy-rst";
> > +
> > +            #interrupt-cells = <1>;
> > +            interrupt-map-mask = <0 0 0 0x7>;
> > +            interrupt-map = <0 0 0 1 &pcie_intc 0>,
> > +                            <0 0 0 2 &pcie_intc 1>,
> > +                            <0 0 0 3 &pcie_intc 2>,
> > +                            <0 0 0 4 &pcie_intc 3>;
> > +            pcie_intc: legacy-interrupt-controller {
> > +                      #address-cells = <0>;
> > +                      #interrupt-cells = <1>;
> > +                      interrupt-controller;
> > +            };
> > +        };
> > +    };
> > -- 
> > 2.25.1
> 
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