Re: [PATCH 05/11] dt-bindings: thermal: k3-j72xx: elaborate on binding descriptions

From: Krzysztof Kozlowski
Date: Wed Oct 12 2022 - 09:38:50 EST


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@xxxxxx>
> ---
> .../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@xxxxxx>
>
> +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