Re: [PATCH v3 3/3] dt-bindings: touchscreen: ad7877: add bindings

[Krzysztof Kozlowski]

On Mon, Sep 09, 2024 at 12:30:13PM +0300, Antoniu Miclaus wrote:
> Add device tree bindings for the ad7877 driver.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> ---
> changes in v3:
>  - use strings for polarity.
>  - use unit siffix where applies.
>  - add defaults where applies.
>  - add complete example.
>  .../input/touchscreen/adi,ad7877.yaml         | 109 ++++++++++++++++++
>  1 file changed, 109 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/adi,ad7877.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/adi,ad7877.yaml b/Documentation/devicetree/bindings/input/touchscreen/adi,ad7877.yaml
> new file mode 100644
> index 000000000000..7603ce63af7e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/adi,ad7877.yaml
> @@ -0,0 +1,109 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/touchscreen/adi,ad7877.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD7877 Touch Screen Controller
> +
> +maintainers:
> +  - Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> +
> +description: |
> +  Analog Devices Touch Screen Controller
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/AD7877.pdf
> +
> +allOf:
> +  - $ref: touchscreen.yaml#
> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad7877
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    description: AD7877 SPI bus clock frequency.
> +    minimum: 10000
> +    maximum: 20000000
> +
> +  adi,stopacq-polarity:
> +    description: The polarity of the signal applied to the STOPACQ pin.
> +    $ref: /schemas/types.yaml#/definitions/string
> +    enum: [low, high]
> +
> +  adi,first-conv-delay-ns:
> +    description: Delay in ns before the first conversion.
> +    enum: [500, 128000, 1000000, 8000000]
> +
> +  adi,pen-down-acc-interval:
> +    description: Enable the ADC to repeatedly perform conversions.
> +                  0 = convert once
> +                  1 = every 0.5 ms
> +                  2 = every 1 ms
> +                  3 = every 8 ms
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [0, 1, 2, 3]
> +    default: 0

You got the comment about using units, right? It applied *everywhere*.
This is clearly a property in ms.

> +
> +  adi,acquisition-time-us:
> +    description: Select acquisition times in us for the ADC.
> +    enum: [2, 4, 8, 16]

What is the default? The property is not reuired, so how does it work
without it?

> +
> +  adi,vref-delay-us:
> +    description: Delay required for the SPI transfers depending on the VREF used.

Same question.

Best regards,
Krzysztof