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Message-ID: <06249fe9-97eb-1ab8-5e35-00b3c613d3a7@linaro.org>
Date:   Wed, 12 Oct 2022 09:36:04 -0400
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Subject: Re: [PATCH 05/11] dt-bindings: thermal: k3-j72xx: elaborate on
 binding descriptions
Content-Language: en-US
To:     Bryan Brattlof <bb@ti.com>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>, Nishanth Menon <nm@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Tero Kristo <kristo@kernel.org>, Keerthy <j-keerthy@ti.com>,
        Linux Thermal <linux-pm@vger.kernel.org>,
        Linux Device Tree <devicetree@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
References: <20221011231727.8090-1-bb@ti.com>
 <20221011231727.8090-6-bb@ti.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20221011231727.8090-6-bb@ti.com>
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Precedence: bulk

On 11/10/2022 19:17, Bryan Brattlof wrote:
> Elaborate on the function of this device node as well as some of the
> properties that this node uses.
> 
> Signed-off-by: Bryan Brattlof <bb@ti.com>
> ---
>  .../bindings/thermal/ti,j72xx-thermal.yaml    | 27 ++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml
> index c74f124ebfc00..0b6a6fa07a532 100644
> --- a/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml
> +++ b/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml
> @@ -9,6 +9,24 @@ title: Texas Instruments J72XX VTM (DTS) binding
>  maintainers:
>    - Keerthy <j-keerthy@ti.com>
>  
> +description: |
> +  The TI K3 family of SoCs typically have a Voltage & Thermal
> +  Management (VTM) device to control up to 8 temperature diode
> +  sensors to measure silicon junction temperatures from different
> +  hotspots of the chip as well as provide temperature, interrupt
> +  and alerting information.
> +
> +  The VTM device will periodically enable these temperature sensors
> +  to make a temperature measurement and store the reported data
> +  allowing the sensors to stay in a reset state when not in use
> +  to maximize the sensor's life.
> +
> +  This VTM driver will then use the following polynomial equation to

"VTM driver" is some physical/electronic element called driver? Or Linux
driver? If the latter, drop it and just describe the equation.

> +  calculate the temperature from the value stored in the VTM device.
> +
> +  Temp = (-9.2627e-12) * x^4 + (6.0373e-08) * x^3 + \
> +         (-1.7058e-04) * x^2 + (3.2512e-01) * x   + (-4.9003e+01)
> +
>  properties:
>    compatible:
>      enum:
> @@ -19,9 +37,16 @@ properties:
>      items:
>        - description: VTM cfg1 register space
>        - description: VTM cfg2 register space
> -      - description: VTM efuse register space
> +      - description: |
> +          A software trimming method must be applied to some Jacinto
> +          devices to function properly. This eFuse region provides
> +          the information needed for these SoCs to report
> +          temperatures accurately.
>  
>    power-domains:
> +    description: |
> +      Should contain the phandle to a power management (PM) domain
> +      node and the device-id of this device.

This is quite generic - why adding it?

>      maxItems: 1
>  
>    "#thermal-sensor-cells":

Best regards,
Krzysztof