[PATCH v2 05/10] dt-bindings: clock: renesas,r8a78000-cpg: Add firmware property

[Geert Uytterhoeven]

Hi Rob,

On Tue, 11 Aug 2026 at 18:33, Rob Herring <robh at kernel.org> wrote:
> On Mon, Aug 03, 2026 at 02:01:18PM +0200, Geert Uytterhoeven wrote:
> > On Thu, 16 Jul 2026 at 23:49, Rob Herring <robh at kernel.org> wrote:
> > > On Fri, Jul 10, 2026 at 01:02:39PM +0200, Geert Uytterhoeven wrote:
> > > > On Fri, 10 Jul 2026 at 12:21, Krzysztof Kozlowski <krzk at kernel.org> wrote:
> > > > > On Wed, Jul 08, 2026 at 12:16:23PM +0200, Geert Uytterhoeven wrote:
> > > > > > Add a firmware property, for systems where SCMI must be used instead of
> > > > > > direct hardware access.
> > > > > >
> > > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
> > > > > > ---
> > > > > > v2:
> > > > > >   - Spin off from "dt-bindings: clock: Document Renesas R-Car X5H Clock
> > > > > >     Pulse Generator".
> > > > > > ---
> > > > > >  .../devicetree/bindings/clock/renesas,r8a78000-cpg.yaml    | 7 +++++++
> > > > > >  1 file changed, 7 insertions(+)
> > > > > >
> > > > > > diff --git a/Documentation/devicetree/bindings/clock/renesas,r8a78000-cpg.yaml b/Documentation/devicetree/bindings/clock/renesas,r8a78000-cpg.yaml
> > > > > > index 4e23bba334382346..fc499e7cf52e4f0c 100644
> > > > > > --- a/Documentation/devicetree/bindings/clock/renesas,r8a78000-cpg.yaml
> > > > > > +++ b/Documentation/devicetree/bindings/clock/renesas,r8a78000-cpg.yaml
> > > > > > @@ -35,6 +35,12 @@ properties:
> > > > > >        <dt-bindings/clock/renesas,r8a78000-cpg.h>.
> > > > > >      const: 1
> > > > > >
> > > > > > +  firmware:
> > > > >
> > > > > RPi is doing similar, but I have doubts. It looks way too close to
> > > > > generic "syscon" which is disallowed.
> > > > >
> > > > > I think this should be vendor+purpose specific, e.g.:
> > > > > "renesas,scmi-transport" or "renesas,scmi-firmware"
> > >
> > > If you can tell me the resource that a 'firmware' provider provides then
> > > it is fine, but you can't.
> >
> > It provides a firmware API, which is not available until the firmware
> > provider is initialized.
>
> I don't know what "a firmware API" is. What does it provide? I know what

It can provide lots of things (everything we are no longer allowed to
touch directly from Linux ;-)

> a clock, GPIO, reset, interrupt, etc. provider is.

A clock is an object you can access through the clock API.
(s/clock/.../ for the other cases).
Firmware is a service (virtual object) you can access through a
firmware API.

In all cases, the consumer of the object or service needs to know
which object or service to use (there can be multiple).

In all cases you cannot access the object or service until it is
available (initialized and registered), for which we have -EPROBE_DEFER,
and/or "[PATCH v2 02/10] of: property: fw_devlink: Add support for
firmware".

Thanks for your understanding ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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