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Date:   Mon, 12 Jul 2021 11:32:16 -0600
From:   Rob Herring <robh@kernel.org>
To:     Thara Gopinath <thara.gopinath@linaro.org>
Cc:     agross@kernel.org, bjorn.andersson@linaro.org, rui.zhang@intel.com,
        daniel.lezcano@linaro.org, viresh.kumar@linaro.org,
        rjw@rjwysocki.net, tdas@codeaurora.org, mka@chromium.org,
        linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [Patch v3 6/6] dt-bindings: thermal: Add dt binding for QCOM LMh
Message-ID: <20210712173216.GA2150396@robh.at.kernel.org>
References: <20210708120656.663851-1-thara.gopinath@linaro.org>
 <20210708120656.663851-7-thara.gopinath@linaro.org>
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On Thu, Jul 08, 2021 at 08:06:56AM -0400, Thara Gopinath wrote:
> Add dt binding documentation to describe Qualcomm
> Limits Management Hardware node.
> 
> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
> ---
>  .../devicetree/bindings/thermal/qcom-lmh.yaml | 100 ++++++++++++++++++
>  1 file changed, 100 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
> 
> diff --git a/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml b/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
> new file mode 100644
> index 000000000000..7f62bd3d543d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
> @@ -0,0 +1,100 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2021 Linaro Ltd.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/thermal/qcom-lmh.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Limits Management Hardware(LMh)
> +
> +maintainers:
> +  - Thara Gopinath <thara.gopinath@linaro.org>
> +
> +description:
> +  Limits Management Hardware(LMh) is a hardware infrastructure on some
> +  Qualcomm SoCs that can enforce temperature and current limits as
> +  programmed by software for certain IPs like CPU.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - qcom,sdm845-lmh
> +
> +  reg:
> +    items:
> +      - description: core registers
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  '#interrupt-cells':
> +    const: 1
> +
> +  interrupt-controller: true
> +
> +  qcom,lmh-cpu-id:
> +    description:
> +      CPU id of the first cpu in the LMh cluster
> +    $ref: /schemas/types.yaml#/definitions/uint32

The way we reference other nodes in DT is phandles. 'cpus' is already 
somewhat established for this case.

> +
> +  qcom,lmh-temperature-arm:
> +    description:
> +      An integer expressing temperature threshold in millicelsius at which

Use unit suffix when you have units.

> +      the LMh thermal FSM is engaged.
> +    $ref: /schemas/types.yaml#/definitions/int32
> +
> +  qcom,lmh-temperature-low:
> +    description:
> +      An integer expressing temperature threshold in millicelsius at which
> +      the LMh thermal FSM is engaged.
> +    $ref: /schemas/types.yaml#/definitions/int32
> +
> +  qcom,lmh-temperature-high:
> +    description:
> +      An integer expressing temperature threshold in millicelsius at which
> +      the LMh thermal FSM is engaged.

What's the difference in the 3 properties because the description is the 
same.

> +    $ref: /schemas/types.yaml#/definitions/int32
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - #interrupt-cells
> +  - interrupt-controller
> +  - qcom,lmh-cpu-id
> +  - qcom,lmh-temperature-arm
> +  - qcom,lmh-temperature-low
> +  - qcom,lmh-temperature-high
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/qcom,rpmh.h>
> +    #include <dt-bindings/interconnect/qcom,sdm845.h>
> +
> +    lmh_cluster1: lmh@17d70800 {
> +      compatible = "qcom,sdm845-lmh";
> +      reg = <0 0x17d70800 0 0x401>;
> +      interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
> +      qcom,lmh-cpu-id = <0x4>;
> +      qcom,lmh-temperature-arm = <65000>;
> +      qcom,lmh-temperature-low = <94500>;
> +      qcom,lmh-temperature-high = <95000>;
> +      interrupt-controller;

What devices is this an interrupt controller for?

> +      #interrupt-cells = <1>;
> +    };
> +  - |
> +    lmh_cluster0: lmh@17d78800 {
> +      compatible = "qcom,sdm845-lmh";
> +      reg = <0 0x17d78800 0 0x401>;
> +      interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
> +      qcom,lmh-cpu-id = <0x0>;
> +      qcom,lmh-temperature-arm = <65000>;
> +      qcom,lmh-temperature-low = <94500>;
> +      qcom,lmh-temperature-high = <95000>;
> +      interrupt-controller;
> +      #interrupt-cells = <1>;
> +    };
> +  - |
> -- 
> 2.25.1
> 
>