Re: [RFC PATCH v3 05/11] dt-bindings: interrupt-controller: Add ACLINT MSWI and SSWI bindings

[Rob Herring <robh@kernel.org>]

On Mon, Aug 30, 2021 at 09:47:23AM +0530, Anup Patel wrote:
> We add DT bindings documentation for the ACLINT MSWI and SSWI
> devices found on RISC-V SOCs.
> 
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
> ---
>  .../riscv,aclint-swi.yaml                     | 95 +++++++++++++++++++
>  1 file changed, 95 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aclint-swi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,aclint-swi.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,aclint-swi.yaml
> new file mode 100644
> index 000000000000..68563259ae24
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,aclint-swi.yaml
> @@ -0,0 +1,95 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/interrupt-controller/riscv,aclint-swi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: RISC-V ACLINT Software Interrupt Devices
> +
> +maintainers:
> +  - Anup Patel <anup.patel@wdc.com>
> +
> +description:
> +  RISC-V SOCs include an implementation of the M-level software interrupt
> +  (MSWI) device and the S-level software interrupt (SSWI) device defined
> +  in the RISC-V Advanced Core Local Interruptor (ACLINT) specification.
> +
> +  The ACLINT MSWI and SSWI devices are documented in the RISC-V ACLINT
> +  specification located at
> +  https://github.com/riscv/riscv-aclint/blob/main/riscv-aclint.adoc.
> +
> +  The ACLINT MSWI and SSWI devices directly connect to the M-level and
> +  S-level software interrupt lines of various HARTs (or CPUs) respectively
> +  so the RISC-V per-HART (or per-CPU) local interrupt controller is the
> +  parent interrupt controller for the ACLINT MSWI and SSWI devices.
> +
> +allOf:
> +  - $ref: /schemas/interrupt-controller.yaml#
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - items:
> +        - enum:
> +          - riscv,aclint-mswi
> +
> +      - items:
> +        - enum:
> +          - riscv,aclint-sswi

All this can be just:

enum:
  - riscv,aclint-mswi
  - riscv,aclint-sswi

However...

> +
> +    description:
> +      For ACLINT MSWI devices, it should be "riscv,aclint-mswi" OR
> +      "<vendor>,<chip>-aclint-mswi".
> +      For ACLINT SSWI devices, it should be "riscv,aclint-sswi" OR
> +      "<vendor>,<chip>-aclint-sswi".

s/OR/AND/

There must be a compatible for the implementation. Unless RiscV 
implementations of specs are complete describing all clocks, power 
domains, resets, etc. and are quirk free.

But don't write free form constraints...


> +
> +  reg:
> +    maxItems: 1
> +
> +  "#interrupt-cells":
> +    const: 0
> +
> +  interrupts-extended:
> +    minItems: 1
> +    maxItems: 4095
> +
> +  interrupt-controller: true
> +
> +additionalProperties: false
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts-extended
> +  - interrupt-controller
> +  - "#interrupt-cells"
> +
> +examples:
> +  - |
> +    // Example 1 (RISC-V MSWI device used by Linux RISC-V NoMMU kernel):
> +
> +    interrupt-controller@2000000 {
> +      compatible = "riscv,aclint-mswi";
> +      interrupts-extended = <&cpu1intc 3>,
> +                            <&cpu2intc 3>,
> +                            <&cpu3intc 3>,
> +                            <&cpu4intc 3>;
> +      reg = <0x2000000 0x4000>;
> +      interrupt-controller;
> +      #interrupt-cells = <0>;
> +    };
> +
> +  - |
> +    // Example 2 (RISC-V SSWI device used by Linux RISC-V MMU kernel):
> +
> +    interrupt-controller@2100000 {
> +      compatible = "riscv,aclint-sswi";
> +      interrupts-extended = <&cpu1intc 1>,
> +                            <&cpu2intc 1>,
> +                            <&cpu3intc 1>,
> +                            <&cpu4intc 1>;
> +      reg = <0x2100000 0x4000>;
> +      interrupt-controller;
> +      #interrupt-cells = <0>;
> +    };
> +...
> -- 
> 2.25.1
> 
>