Re: [PATCH v3 04/12] of: property: fw_devlink: Add support for renesas,scmi-firmware

[Geert Uytterhoeven]

Hi Rob,

On Fri, 18 Sept 2026 at 00:16, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Wed, Sep 02, 2026 at 01:29:20PM +0200, Geert Uytterhoeven wrote:
> > Let fw_devlink create device links between consumers and suppliers of
> > SCMI firmware on Renesas platforms, and enforce these dependencies.
> >
> > This prevents probing of drivers before the firmware they depend on
> > becomes available, thus avoiding unneeded probe deferrals.
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > ---
> > v3:
> >   - s/firmware/renesas,scmi-firmware/,

> > +++ b/drivers/of/property.c
> > @@ -1417,6 +1417,7 @@ DEFINE_SIMPLE_PROP(power_supplies, "power-supplies", NULL)
> >  DEFINE_SIMPLE_PROP(mmc_pwrseq, "mmc-pwrseq", NULL)
> >  DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
> >  DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
> > +DEFINE_SIMPLE_PROP(renesas_scmi_firmware, "renesas,scmi-firmware", NULL)
> >
> >  static struct device_node *parse_pinctrl_n(struct device_node *np,
> >                                          const char *prop_name, int index)
> > @@ -1574,6 +1575,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
> >       { .parse_prop = parse_regulators, },
> >       { .parse_prop = parse_gpio, },
> >       { .parse_prop = parse_gpios, },
> > +     { .parse_prop = parse_renesas_scmi_firmware, },
>
> This is going to be a catch-22, we can't have vendor specific properties
> here. If we need this, we need to come up with a distributed way to
> declare them. Linker section tricks is one way. Maybe something in the
> driver struct would work?

Quoting myself:
"I still think the vendor prefix should be dropped, or replaced by "arm".

> Can you just avoid a property altogether? Why can't you check for the
> presence of SCMI at runtime?

A system can have multiple SCMI providers, so
of_find_compatible_node(..., "arm,scmi") is not sufficient to find
the right one.

Gr{oetje,eeting}s,

                        Geert

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

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