On Tue, Nov 03, 2026 at 11:11:31AM +1100, Kohei Otsuka wrote:
> Core16550 is a 16550-compatible UART soft IP core for Microchip FPGAs,
> including the fabric of PolarFire SoC. Its registers follow the 16550A,
> so ns16550a stays the fallback, but

> it raises no interrupt on TEMT,
> which the driver has to know about to support RS-485 on it.

Doesn't this exclude using the fallback to ns16550a, since it requires
specific interrupt handling?

> 
> Add microchip,core16550 with ns16550a as the fallback.
> 
> Link: https://github.com/linux4microchip/meta-mchp/issues/5
> Signed-off-by: Kohei Otsuka <kohei@spacemachines.com>
> ---
>  Documentation/devicetree/bindings/serial/8250.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/serial/8250.yaml b/Documentation/devicetree/bindings/serial/8250.yaml
> index 50d5c977afa3..33a5929bdaa6 100644
> --- a/Documentation/devicetree/bindings/serial/8250.yaml
> +++ b/Documentation/devicetree/bindings/serial/8250.yaml
> @@ -137,6 +137,7 @@ properties:
>                - ti,da830-uart
>                - loongson,ls2k0500-uart
>                - loongson,ls2k1500-uart
> +              - microchip,core16550

This needs a -rtl-vX suffix on the end, as is used for other fabric
cores - see microchip,corei2c.yaml for an example.

pw-bot: changes-requested

Thanks,
Conor.

>            - const: ns16550a
>        - items:
>            - enum:
> 
> -- 
> 2.53.0
>