[RFC PATCH v1 09/10] dt-bindings: timer: Add ACLINT MSWI and SSWI bindings

[Rob Herring]

On Sat, Jun 12, 2021 at 09:34:21PM +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 at wdc.com>
> ---
>  .../riscv,aclint-swi.yaml                     | 82 +++++++++++++++++++
>  1 file changed, 82 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..bed15411c18f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,aclint-swi.yaml
> @@ -0,0 +1,82 @@
> +# 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 at 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:
> +    items:
> +      - enum:
> +          - riscv,aclint-mswi
> +          - riscv,aclint-sswi
> +
> +    description:
> +      Should be "<vendor>,<chip>-aclint-mswi" and "riscv,aclint-mswi" OR
> +      "<vendor>,<chip>-aclint-sswi" and "riscv,aclint-sswi".

Don't write descriptions that should be schemas.

Is there no vendor or specific implementation yet?

You can write "pattern: '.*,.*-aclint-sswi$' as an entry with a comment 
to add specific compatibles.

> +
> +  reg:
> +    maxItems: 1
> +
> +  "#interrupt-cells":
> +    const: 0
> +
> +  interrupts-extended:
> +    minItems: 1

maxItems? 

> +
> +  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 at 2000000 {
> +      compatible = "riscv,aclint-mswi";
> +      interrupts-extended = <&cpu1intc 3 &cpu2intc 3 &cpu3intc 3 &cpu4intc 3>;

format as: <&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 at 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
> 
>