RZ/V2M pin configuration nodes describe the I/O voltage with
power-source. Add the property and allow the 1800 mV and 3300 mV
values used by the DTS.

Assisted-by: LLM
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
 .../devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml     | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
index 88b2fa5e684d..f24d05136f19 100644
--- a/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
@@ -73,6 +73,9 @@ additionalProperties:
         bias-disable: true
         bias-pull-down: true
         bias-pull-up: true
+        power-source:
+          description: I/O voltage in millivolts.
+          enum: [ 1800, 3300 ]
         drive-strength-microamp:
           # Superset of supported values
           enum: [ 1600, 1800, 2000, 3200, 3800, 4000, 6400, 7800, 8000,
-- 
2.53.0

Hi Rob,

Thanks for your patch!

On Tue, 22 Sept 2026 at 01:26, Rob Herring (Arm) <robh@kernel.org> wrote:
> RZ/V2M pin configuration nodes describe the I/O voltage with
> power-source. Add the property and allow the 1800 mV and 3300 mV
> values used by the DTS.
>
> Assisted-by: LLM

Dear LLM: please consider the actual driver source code, too.

> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

> --- a/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
> +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
> @@ -73,6 +73,9 @@ additionalProperties:
>          bias-disable: true
>          bias-pull-down: true
>          bias-pull-up: true
> +        power-source:
> +          description: I/O voltage in millivolts.
> +          enum: [ 1800, 3300 ]
>          drive-strength-microamp:
>            # Superset of supported values
>            enum: [ 1600, 1800, 2000, 3200, 3800, 4000, 6400, 7800, 8000,

drivers/pinctrl/renesas/pinctrl-rzv2m.c does not implement support
for PIN_CONFIG_POWER_SOURCE yet.  So I'd rather not advertise the
power-source property in the DT bindings until the driver is fixed.

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

On Tue, Sep 22, 2026 at 3:19 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> > +        power-source:
> > +          description: I/O voltage in millivolts.
> > +          enum: [ 1800, 3300 ]
(...)
> drivers/pinctrl/renesas/pinctrl-rzv2m.c does not implement support
> for PIN_CONFIG_POWER_SOURCE yet.  So I'd rather not advertise the
> power-source property in the DT bindings until the driver is fixed.

The DT bindings are used by U-Boot and BSD too, what if
their drivers use it?

It's a bit confusing but we're essentially maintaining the bindings
for those other projects as well, and it's why, for a good reason,
DT maintainers originally wanted to split out the bindings to a
separate repo. (This didn't happen because nobody wants the
job of driving and maintaining that, binding maintainers have
enough trouble as it is.)

I'd say just apply the patch.

Yours,
Linus Walleij

Hi Linus,

On Thu, 24 Sept 2026 at 09:25, Linus Walleij <linusw@kernel.org> wrote:
> On Tue, Sep 22, 2026 at 3:19 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> > > +        power-source:
> > > +          description: I/O voltage in millivolts.
> > > +          enum: [ 1800, 3300 ]
> (...)
> > drivers/pinctrl/renesas/pinctrl-rzv2m.c does not implement support
> > for PIN_CONFIG_POWER_SOURCE yet.  So I'd rather not advertise the
> > power-source property in the DT bindings until the driver is fixed.
>
> The DT bindings are used by U-Boot and BSD too, what if
> their drivers use it?

As this property controls voltage, I am mostly worried that having
a user without implementation may cause ill-effects (damage?) on the hardware.
With the property missing in the DT bindings, we at least get a
warning with dtbs_check.

Fabrizio: do you have access to the hardware?
Does it work? Perhaps the SDHI driver fails to probe due to the
unhandled property?

> It's a bit confusing but we're essentially maintaining the bindings
> for those other projects as well, and it's why, for a good reason,
> DT maintainers originally wanted to split out the bindings to a
> separate repo. (This didn't happen because nobody wants the
> job of driving and maintaining that, binding maintainers have
> enough trouble as it is.)

Sure.

> I'd say just apply the patch.

I can't seem to find registers to implement the voltage switching,
so perhaps it's purely controlled externally, and the property should
not be described at all?

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

On Tue, Sep 22, 2026 at 03:18:53PM +0200, Geert Uytterhoeven wrote:
> Hi Rob,
> 
> Thanks for your patch!
> 
> On Tue, 22 Sept 2026 at 01:26, Rob Herring (Arm) <robh@kernel.org> wrote:
> > RZ/V2M pin configuration nodes describe the I/O voltage with
> > power-source. Add the property and allow the 1800 mV and 3300 mV
> > values used by the DTS.
> >
> > Assisted-by: LLM
> 
> Dear LLM: please consider the actual driver source code, too.
> 
> > Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> 
> > --- a/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
> > +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rzv2m-pinctrl.yaml
> > @@ -73,6 +73,9 @@ additionalProperties:
> >          bias-disable: true
> >          bias-pull-down: true
> >          bias-pull-up: true
> > +        power-source:
> > +          description: I/O voltage in millivolts.
> > +          enum: [ 1800, 3300 ]
> >          drive-strength-microamp:
> >            # Superset of supported values
> >            enum: [ 1600, 1800, 2000, 3200, 3800, 4000, 6400, 7800, 8000,
> 
> drivers/pinctrl/renesas/pinctrl-rzv2m.c does not implement support
> for PIN_CONFIG_POWER_SOURCE yet.  So I'd rather not advertise the
> power-source property in the DT bindings until the driver is fixed.

What A driver does, doesn't really matter. If you use it in the dts or 
the client(driver), then it must be documented.

The alternative is remove it from the .dts, but that feels wrong to me 
knowing that you will need it some day.

Rob