Re: [PATCH] dt-bindings: timer: Convert Exynos MCT bindings to json-schema

[Rob Herring <robh@kernel.org>]

On Mon, Sep 09, 2019 at 06:25:37PM +0200, Krzysztof Kozlowski wrote:
> Convert Samsung Exynos Soc Multi Core Timer bindings to DT schema format
> using json-schema.
> 
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> ---
>  .../bindings/timer/samsung,exynos4210-mct.txt |  88 --------------
>  .../timer/samsung,exynos4210-mct.yaml         | 115 ++++++++++++++++++
>  2 files changed, 115 insertions(+), 88 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt
>  create mode 100644 Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.yaml


> diff --git a/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.yaml b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.yaml
> new file mode 100644
> index 000000000000..b96d2877955f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.yaml
> @@ -0,0 +1,115 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/timer/samsung,exynos4210-mct.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Samsung Exynos SoC Multi Core Timer (MCT)
> +
> +maintainers:
> +  - Krzysztof Kozlowski <krzk@kernel.org>
> +
> +description: |+
> +  The Samsung's Multi Core Timer (MCT) module includes two main blocks, the
> +  global timer and CPU local timers. The global timer is a 64-bit free running
> +  up-counter and can generate 4 interrupts when the counter reaches one of the
> +  four preset counter values. The CPU local timers are 32-bit free running
> +  down-counters and generate an interrupt when the counter expires. There is
> +  one CPU local timer instantiated in MCT for every CPU in the system.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - samsung,exynos4210-mct
> +      - samsung,exynos4412-mct
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    description: |
> +      Interrupts should be put in specific order. This is, the local timer
> +      interrupts should be specified after the four global timer interrupts
> +      have been specified:
> +      0: Global Timer Interrupt 0
> +      1: Global Timer Interrupt 1
> +      2: Global Timer Interrupt 2
> +      3: Global Timer Interrupt 3
> +      4: Local Timer Interrupt 0
> +      5: Local Timer Interrupt 1
> +      6: ..
> +      7: ..
> +      i: Local Timer Interrupt n
> +      For MCT block that uses a per-processor interrupt for local timers, such
> +      as ones compatible with "samsung,exynos4412-mct", only one local timer
> +      interrupt might be specified, meaning that all local timers use the same
> +      per processor interrupt.
> +    minItems: 5               # 4 Global + 1 local
> +    maxItems: 20              # 4 Global + 16 local
> +
> +required:
> +  - compatible
> +  - interrupts
> +  - reg
> +
> +examples:
> +  - |
> +    // In this example, the IP contains two local timers, using separate
> +    // interrupts, so two local timer interrupts have been specified,
> +    // in addition to four global timer interrupts.
> +      mct@10050000 {

Can we clean this up and use 'timer' here.

> +        compatible = "samsung,exynos4210-mct";
> +        reg = <0x10050000 0x800>;
> +        interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
> +                     <0 42 0>, <0 48 0>;
> +      };
> +
> +  - |
> +    // In this example, the timer interrupts are connected to two separate
> +    // interrupt controllers. Hence, an interrupt-map is created to map
> +    // the interrupts to the respective interrupt controllers.
> +
> +    mct@101c0000 {
> +      compatible = "samsung,exynos4210-mct";
> +      reg = <0x101C0000 0x800>;
> +      interrupt-parent = <&mct_map>;
> +      interrupts = <0>, <1>, <2>, <3>, <4>, <5>;
> +
> +      mct_map: mct-map {

This needs to be documented.

Note, I don't really see any reason this needs to be a child node.

> +        #interrupt-cells = <1>;
> +        #address-cells = <0>;
> +        #size-cells = <0>;
> +        interrupt-map = <0 &gic 0 57 0>,
> +                        <1 &gic 0 69 0>,
> +                        <2 &combiner 12 6>,
> +                        <3 &combiner 12 7>,
> +                        <4 &gic 0 42 0>,
> +                        <5 &gic 0 48 0>;
> +      };
> +    };
> +
> +  - |
> +    // In this example, the IP contains four local timers, but using
> +    // a per-processor interrupt to handle them. Only one first local
> +    // interrupt is specified.
> +
> +    mct@10050000 {
> +      compatible = "samsung,exynos4412-mct";
> +      reg = <0x10050000 0x800>;
> +
> +      interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
> +                   <0 42 0>;
> +    };
> +
> +  - |
> +    // In this example, the IP contains four local timers, but using
> +    // a per-processor interrupt to handle them. All the local timer
> +    // interrupts are specified.
> +
> +    mct@10050000 {
> +      compatible = "samsung,exynos4412-mct";
> +      reg = <0x10050000 0x800>;
> +
> +      interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
> +                   <0 42 0>, <0 42 0>, <0 42 0>, <0 42 0>;
> +    };
> -- 
> 2.17.1
>