Re: [PATCH v4 05/29] dt-bindings: bus: Add simple-platform-bus

Geert Uytterhoeven
2025-10-31T08:58:32Z

Hi Hervé,

On Wed, 15 Oct 2025 at 09:17, Herve Codina <herve.codina@bootlin.com> wrote:
> A Simple Platform Bus is a transparent bus that doesn't need a specific
> driver to perform operations at bus level.
>
> Similar to simple-bus, a Simple Platform Bus allows to automatically
> instantiate devices connected to this bus.
>
> Those devices are instantiated only by the Simple Platform Bus probe
> function itself.
>
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Thanks for your patch!

> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/simple-platform-bus.yaml
> @@ -0,0 +1,50 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/bus/simple-platform-bus.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Simple Platform Bus
> +
> +maintainers:
> + - Herve Codina <herve.codina@bootlin.com>
> +
> +description: |
> + A Simple Platform Bus is a transparent bus that doesn't need a specific
> + driver to perform operations at bus level.
> +
> + Similar to simple-bus, a Simple Platform Bus allows to automatically
> + instantiate devices connected to this bus. Those devices are instantiated
> + only by the Simple Platform Bus probe function itself.

So what are the differences with simple-bus? That its children are
instantiated "only by the Simple Platform Bus probe function itself"?
If that is the case, in which other places are simple-bus children
instantiated?

Do we need properties related to power-management (clocks, power-domains),
or will we need a "simple-pm-platform-bus" later? ;-)

FTR, I still think we wouldn't have needed the distinction between
"simple-bus" and "simple-pm-bus"...

Gr{oetje,eeting}s,

Geert

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

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds