Re: [PATCH v2 1/2] dt-bindings: gpio: add gpio-aggregator binding

[Linus Walleij]

On Fri, Feb 20, 2026 at 5:57 AM James Hilliard
<james.hilliard1@xxxxxxxxx> wrote:

> Yeah, I did investigate adding gpio-line-names support to gpio-map,
> but there was no clear way that I saw to actually implement it in the
> kernel. Maybe there's some way I missed however.

Check commit bd6f2fd5a1d52198468c5cdc3c2472362dff5aaa
"of: Support parsing phandle argument lists through a nexus node"

of_parse_phandle_with_args_map() in drivers/of/base.c is where
the magic happens.

This is called from drivers/gpio/gpiolib-of.c, in of_get_named_gpiod_flags(),
so as you see mapping doesn't really happen until you use it.
There is no way we can assign the line name on the mapping
path itself.

What we would have to do is to add code to gpiolib-of.c to scan the
whole device tree whenever a new gpiochip from a gpio-controller
node is added and look for any "gpio-map" with phandles to the provider,
and if that exist, index and parse gpio-line-names from the nexus
node to override the default (if any) that is set for the gpio controller.

Not impossible just a bit quirky.

Yours,
Linus Walleij