Re: [PATCH v2 2/9] dt-bindings: spi: zynqmp-qspi: Add example dual upper/lower bus

[David Lechner <dlechner@baylibre.com>]

On 6/16/25 5:00 PM, Sean Anderson wrote:
> Add an example of the spi-buses property showcasing how to have devices
> on both the upper and lower buses.
> 
> Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
> ---
> 
> Changes in v2:
> - New
> 
>  .../bindings/spi/spi-zynqmp-qspi.yaml         | 22 ++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-zynqmp-qspi.yaml b/Documentation/devicetree/bindings/spi/spi-zynqmp-qspi.yaml
> index 02cf1314367b..c6a57fbb9dcf 100644
> --- a/Documentation/devicetree/bindings/spi/spi-zynqmp-qspi.yaml
> +++ b/Documentation/devicetree/bindings/spi/spi-zynqmp-qspi.yaml


In addition to changing the example, we could also extend the
spi-buses property for this controller since we know this controller
has 2 buses.

  properties:
    ...

    spi-buses:
      description: 0 is the "lower" bus, 1 is the "upper" bus
      maxItems: 2
      items:
        enum: [0, 1]

Not sure what to do about the default though since as discussed elsewhere,
this controller needs the default bus number to be the CS number for
backwards compatibility rather than `default: [0]` as is specified in the
previous patch.

I suppose we could leave default out of the generic binding and leave it
up to each individual controller to decide how to handle that.

> @@ -69,7 +69,7 @@ examples:
>        #address-cells = <2>;
>        #size-cells = <2>;
>  
> -      qspi: spi@ff0f0000 {
> +      qspi: spi-controller@ff0f0000 {

It seems more common to have spi@ rather than spi-controller@.
Is there a push to change this in general?

>          compatible = "xlnx,zynqmp-qspi-1.0";
>          clocks = <&zynqmp_clk 53>, <&zynqmp_clk 82>;
>          clock-names = "ref_clk", "pclk";