Re: [RFC PATCH 1/2] dt-bindings: i2c: renesas,rcar-i2c: document SMBusAlert usage

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Wolfram,

On Mon, Aug 26, 2024 at 5:08 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> Question: Should I remove 'smbus_alert' from the enum of
> 'interrupt-names'? It is already documented here:
>
> https://github.com/devicetree-org/dt-schema/commit/c51125d571cac9596048e888a856d70650e400e0

Thanks for your patch!

> --- a/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
> @@ -60,7 +60,20 @@ properties:
>      maxItems: 1
>
>    interrupts:
> -    maxItems: 1
> +    minItems: 1
> +    maxItems: 2
> +    description:
> +      Without interrupt-names, the first interrupt listed must be the one
> +      of the IP core, the second optional interrupt listed must handle
> +      SMBALERT#, likely a GPIO.
> +
> +  interrupt-names:
> +    minItems: 1
> +    maxItems: 2
> +    items:
> +      enum:
> +        - main
> +        - smbus_alert
>
>    clock-frequency:
>      description:

IIUIC, this is not a property of the hardware, but a side-channel
independent from the actual I2C controller hardware? Then a generic
"smbus-alert-gpios" property sounds more appropriate to me.

BTW, are you aware of any I2C controller having a dedicated input pin
for this?

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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