Re: [PATCH 1/5] dt-bindings: display: panel: samsung,atna33xc20: Document ATNA45AF01

[Doug Anderson]

Hi,

On Wed, Jul 10, 2024 at 10:05 AM Stephan Gerhold
<stephan.gerhold@xxxxxxxxxx> wrote:
>
> The Samsung ATNA45AF01 panel is an AMOLED eDP panel that has backlight
> control over the DP AUX channel. While it works almost correctly with the
> generic "edp-panel" compatible, the backlight needs special handling to
> work correctly. It is similar to the existing ATNA33XC20 panel, just with
> a larger resolution and size.
>
> Add a new "samsung,atna45af01" compatible to describe this panel in the DT.
>
> Signed-off-by: Stephan Gerhold <stephan.gerhold@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/display/panel/samsung,atna33xc20.yaml       | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/display/panel/samsung,atna33xc20.yaml b/Documentation/devicetree/bindings/display/panel/samsung,atna33xc20.yaml
> index 765ca155c83a..d668e8d0d296 100644
> --- a/Documentation/devicetree/bindings/display/panel/samsung,atna33xc20.yaml
> +++ b/Documentation/devicetree/bindings/display/panel/samsung,atna33xc20.yaml
> @@ -14,7 +14,11 @@ allOf:
>
>  properties:
>    compatible:
> -    const: samsung,atna33xc20
> +    enum:
> +      # Samsung 13.3" FHD (1920x1080 pixels) eDP AMOLED panel
> +      - samsung,atna33xc20
> +      # Samsung 14.5" WQXGA+ (2880x1800 pixels) eDP AMOLED panel
> +      - samsung,atna45af01

Seems OK, but a few thoughts:

1. Is it worth renaming this file? Something like
"samsung,atna-oled-panel.yaml"? I'd be interested in DT maintainer
folks' opinions here.

2. In theory you could make your compatible look like this:

compatible = "samsung,atna45af01", "samsung,atna33xc20"

...which would say "I have a 45af01 but if the OS doesn't have
anything special to do that it would be fine to use the 33xc20
driver". That would allow device trees to work without the kernel
changes and would allow you to land the DT changes in parallel with
the driver changes and things would keep working.

...and, in fact, that would mean you _didn't_ need to add the new
compatible string to the driver, which is nice.


-Doug