Re: [PATCH v2 02/14] dt-bindings: iio: accel: bosch,bma220 setup SPI clock mode

Jonathan Cameron
2025-09-10T17:48:18Z

On Wed, 10 Sep 2025 10:57:07 +0300
Petre Rodan <petre.rodan@subdimension.ro> wrote:

> Assert CPOL for a high-idle clock signal and CPHA for sampling on the
> trailing (rising) edge.
>
> Quoting from the datasheet:
>
> "During the transitions on CSB, SCK must be high. SDI and SDO are driven
> at the falling edge of SCK and should be captured at the rising edge of
> SCK."
>
> The sensor does not function with the default SPI clock mode.
>
> Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>

Perhaps this one deserves a fixes tag? I'm not 100% sure for
dt-bindings that are broken like this.

> ---
> ChangeLog:
> - split out from a bigger patch file
> ---
> Documentation/devicetree/bindings/iio/accel/bosch,bma220.yaml | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/accel/bosch,bma220.yaml b/Documentation/devicetree/bindings/iio/accel/bosch,bma220.yaml
> index da047258aca3d84e8b2cbe92a9c98309236fe7ae..0e27ec74065acca611e63309d6ae889b8a3134ce 100644
> --- a/Documentation/devicetree/bindings/iio/accel/bosch,bma220.yaml
> +++ b/Documentation/devicetree/bindings/iio/accel/bosch,bma220.yaml
> @@ -20,6 +20,9 @@ properties:
> interrupts:
> maxItems: 1
>
> + spi-cpha: true
> + spi-cpol: true
> +
> vdda-supply: true
> vddd-supply: true
> vddio-supply: true
> @@ -44,6 +47,8 @@ examples:
> compatible = "bosch,bma220";
> reg = <0>;
> spi-max-frequency = <2500000>;
> + spi-cpol;
> + spi-cpha;
> interrupt-parent = <&gpio0>;
> interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
> };
>