Re: [PATCH 1/2] dt-bindings: pci: Add DT bindings for apple,pcie

[Robin Murphy <robin.murphy@arm.com>]

On 2021-05-16 22:18, Mark Kettenis wrote:
> From: Mark Kettenis <kettenis@openbsd.org>
> 
> The Apple PCIe host controller is a PCIe host controller with
> multiple root ports present in Apple ARM SoC platforms, including
> various iPhone and iPad devices and the "Apple Silicon" Macs.
> 
> Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
> ---
>   .../devicetree/bindings/pci/apple,pcie.yaml   | 150 ++++++++++++++++++
>   MAINTAINERS                                   |   1 +
>   2 files changed, 151 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/pci/apple,pcie.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pci/apple,pcie.yaml b/Documentation/devicetree/bindings/pci/apple,pcie.yaml
> new file mode 100644
> index 000000000000..af3c9f64e380
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/apple,pcie.yaml
> @@ -0,0 +1,150 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/apple,pcie.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple PCIe host controller
> +
> +maintainers:
> +  - Mark Kettenis <kettenis@openbsd.org>
> +
> +description: |
> +  The Apple PCIe host controller is a PCIe host controller with
> +  multiple root ports present in Apple ARM SoC platforms, including
> +  various iPhone and iPad devices and the "Apple Silicon" Macs.
> +
> +allOf:
> +  - $ref: /schemas/pci/pci-bus.yaml#
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: apple,t8103-pcie
> +      - const: apple,pcie
> +
> +  reg:
> +    minItems: 4
> +    maxItems: 6
> +
> +  reg-names:
> +    minItems: 4
> +    maxItems: 7
> +    items:
> +      - const: ecam
> +      - const: rc
> +      - const: phy
> +      - const: port0
> +      - const: port1
> +      - const: port2
> +
> +  ranges:
> +    minItems: 2
> +    maxItems: 2
> +
> +  interrupts:
> +    minItems: 3
> +    maxItems: 3
> +
> +  msi-ranges:
> +    description:
> +      A list of pairs <intid span>, where "intid" is the first
> +      interrupt number that can be used as an MSI, and "span" the size
> +      of that range.
> +    $ref: /schemas/types.yaml#/definitions/uint32-matrix
> +    items:
> +      minItems: 2
> +      maxItems: 2
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - bus-range
> +  - interrupts
> +  - msi-controller
> +  - msi-parent
> +  - msi-ranges
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/apple-aic.h>
> +    #include <dt-bindings/pinctrl/apple.h>
> +
> +    soc {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      pcie0: pcie@690000000 {
> +        compatible = "apple,t8103-pcie", "apple,pcie";
> +        device_type = "pci";
> +
> +        reg = <0x6 0x90000000 0x0 0x1000000>,
> +              <0x6 0x80000000 0x0 0x4000>,
> +              <0x6 0x8c000000 0x0 0x4000>,
> +              <0x6 0x81000000 0x0 0x8000>,
> +              <0x6 0x82000000 0x0 0x8000>,
> +              <0x6 0x83000000 0x0 0x8000>;
> +        reg-names = "ecam", "rc", "phy", "port0", "port1", "port2";
> +
> +        interrupt-parent = <&aic>;
> +        interrupts = <AIC_IRQ 695 IRQ_TYPE_LEVEL_HIGH>,
> +                     <AIC_IRQ 698 IRQ_TYPE_LEVEL_HIGH>,
> +                     <AIC_IRQ 701 IRQ_TYPE_LEVEL_HIGH>;
> +
> +        msi-controller;
> +        msi-parent = <&pcie0>;
> +        msi-ranges = <704 32>;
> +
> +        iommu-map = <0x0 &dart0 0x8000 0x100>,
> +                    <0x100 &dart0 0x100 0x100>,
> +                    <0x200 &dart1 0x200 0x100>,
> +                    <0x300 &dart2 0x300 0x100>;
> +        iommu-map-mask = <0xff00>;

This doesn't quite add up - if the mask is ignoring the bottom 8 bits, 
then each of those map entries is describing one single ID mapping, not 256.

> +        bus-range = <0 7>;

Given that the iommu-map only covers buses 0-3, what happens to traffic 
from buses 4-7?

Robin.

> +        #address-cells = <3>;
> +        #size-cells = <2>;
> +        ranges = <0x43000000 0x6 0xa0000000 0x6 0xa0000000 0x0 0x20000000>,
> +                 <0x02000000 0x0 0xc0000000 0x6 0xc0000000 0x0 0x40000000>;
> +
> +        clocks = <&pcie_core_clk>, <&pcie_aux_clk>, <&pcie_ref_clk>;
> +        pinctrl-0 = <&pcie_pins>;
> +        pinctrl-names = "default";
> +
> +        pci@0,0 {
> +          device_type = "pci";
> +          reg = <0x0 0x0 0x0 0x0 0x0>;
> +          reset-gpios = <&pinctrl_ap 152 0>;
> +          max-link-speed = <2>;
> +
> +          #address-cells = <3>;
> +          #size-cells = <2>;
> +          ranges;
> +        };
> +
> +        pci@1,0 {
> +          device_type = "pci";
> +          reg = <0x800 0x0 0x0 0x0 0x0>;
> +          reset-gpios = <&pinctrl_ap 153 0>;
> +          max-link-speed = <2>;
> +
> +          #address-cells = <3>;
> +          #size-cells = <2>;
> +          ranges;
> +        };
> +
> +        pci@2,0 {
> +          device_type = "pci";
> +          reg = <0x1000 0x0 0x0 0x0 0x0>;
> +          reset-gpios = <&pinctrl_ap 33 0>;
> +          max-link-speed = <1>;
> +
> +          #address-cells = <3>;
> +          #size-cells = <2>;
> +          ranges;
> +        };
> +      };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7327c9b778f1..789d79315485 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1654,6 +1654,7 @@ C:	irc://chat.freenode.net/asahi-dev
>   T:	git https://github.com/AsahiLinux/linux.git
>   F:	Documentation/devicetree/bindings/arm/apple.yaml
>   F:	Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
> +F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
>   F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
>   F:	arch/arm64/boot/dts/apple/
>   F:	drivers/irqchip/irq-apple-aic.c
>