Re: [PATCH v2 2/6] dt-bindings: PCI: Add bindings for brcmstb's PCIe device

[Nicolas Saenz Julienne]

Hi Rob, thanks for the review.

On Mon, 2019-11-18 at 15:23 -0600, Rob Herring wrote:
> On Tue, Nov 12, 2019 at 04:59:21PM +0100, Nicolas Saenz Julienne wrote:
> > From: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> > 
> > The DT bindings description of the brcmstb PCIe device is described.
> > This node can only be used for now on the Raspberry Pi 4.
> > 
> > Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> > 
> > ---
> > 
> > Changes since v1:
> >   - Fix commit Subject
> >   - Remove linux,pci-domain
> > 
> > This was based on Jim's original submission[1], converted to yaml and
> > adapted to the RPi4 case.
> > 
> > [1] https://patchwork.kernel.org/patch/10605937/
> > 
> >  .../bindings/pci/brcm,stb-pcie.yaml           | 110 ++++++++++++++++++
> >  1 file changed, 110 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> > b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> > new file mode 100644
> > index 000000000000..4cbb18821300
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
> > @@ -0,0 +1,110 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pci/brcm,stb-pcie.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Brcmstb PCIe Host Controller Device Tree Bindings
> > +
> > +maintainers:
> > +  - Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> > +
> 
> I added a common PCI schema to dt-schema. You can reference it here:
> 
> allOf:
>   - $ref: /schemas/pci/pci-bus.yaml#

Thanks!

> > +properties:
> > +  compatible:
> > +    const: brcm,bcm2711-pcie # The Raspberry Pi 4
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    minItems: 1
> > +    maxItems: 2
> > +    items:
> > +      - description: PCIe host controller
> > +      - description: builtin MSI controller
> > +
> > +  interrupt-names:
> > +    minItems: 1
> > +    maxItems: 2
> > +    items:
> > +      - const: pcie
> > +      - const: msi
> > +
> > +  "#address-cells":
> > +    const: 3
> > +
> > +  "#size-cells":
> > +    const: 2
> > +
> > +  "#interrupt-cells":
> > +    const: 1
> > +
> > +  interrupt-map-mask: true
> > +
> > +  interrupt-map: true
> 
> Drop all these as the pci-bus.yaml will cover them.

OK

> > +
> > +  ranges: true
> 
> Do you know many entries, if not, you can drop it too?

As this is only aimed at the RPi4's controller we know. Only one for now, same
for dma-ranges.

> > +
> > +  dma-ranges: true
> 
> Do you know many entries, if not, you can drop it too?
> 
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  clock-names:
> > +    items:
> > +      - const: sw_pcie
> > +
> > +  msi-controller:
> > +    description: Identifies the node as an MSI controller.
> > +    type: boolean
> > +
> > +  msi-parent:
> > +    description: MSI controller the device is capable of using.
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> 
> Assume these 2 have a type defined.

Ok

> > +
> > +  brcm,enable-ssc:
> > +    description: Indicates usage of spread-spectrum clocking.
> > +    type: boolean
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - "#address-cells"
> > +  - "#size-cells"
> > +  - "#interrupt-cells"
> > +  - interrupt-map-mask
> > +  - interrupt-map
> > +  - ranges
> > +  - dma-ranges
> 
> You can drop ranges, #address-cells and #size-cells as they are required 
> in pci-bus.yaml.
> 
> Shouldn't interrupts, interrupt-names, and msi-controller all be 
> required?

Agree, I've have doubts with msi-controller, but I guess the HW is still a
msi-controller regardless of whether you use it so it reasonable to require it.

> > +
> > +additionalProperties: false
> 
> This won't work having the commmon binding, but 
> 'unevaluatedProperties: false' will (eventually when json-schema draft8 
> is supported). 

I'll change it.

> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > +    scb {
> > +            #address-cells = <2>;
> > +            #size-cells = <1>;
> > +            pcie0: pcie@7d500000 {
> > +                    compatible = "brcm,bcm2711-pcie";
> > +                    reg = <0x0 0x7d500000 0x9310>;
> > +                    #address-cells = <3>;
> > +                    #size-cells = <2>;
> > +                    #interrupt-cells = <1>;
> > +                    interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
> > +                                 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
> > +                    interrupt-names = "pcie", "msi";
> > +                    interrupt-map-mask = <0x0 0x0 0x0 0x7>;
> > +                    interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143
> > IRQ_TYPE_LEVEL_HIGH
> > +                                     0 0 0 2 &gicv2 GIC_SPI 144
> > IRQ_TYPE_LEVEL_HIGH
> > +                                     0 0 0 3 &gicv2 GIC_SPI 145
> > IRQ_TYPE_LEVEL_HIGH
> > +                                     0 0 0 4 &gicv2 GIC_SPI 146
> > IRQ_TYPE_LEVEL_HIGH>;
> 
> Bracket each entry. The schema is making this stricter.

Noted.

Regards,
Nicolas

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