Re: [PATCH] dt-bindings: pinctrl: renesas: Allow power-source

Hi Linus,

On Thu, 24 Sept 2026 at 09:25, Linus Walleij [off-list ref] wrote:

On Tue, Sep 22, 2026 at 3:19 PM Geert Uytterhoeven [off-list ref] wrote:

quoted

quoted

+        power-source:
+          description: I/O voltage in millivolts.
+          enum: [ 1800, 3300 ]

(...)

quoted

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