Re: [PATCH v8 04/11] arm64: dts: renesas: add support for solidrun rzg2l som and hb-iiot evb

[Geert Uytterhoeven]

Hi Josua,

On Mon, 28 Sept 2026 at 16:11, Josua Mayer <josua@xxxxxxxxxxxxx> wrote:
> Am 23.09.26 um 16:37 schrieb Geert Uytterhoeven:
> > On Fri, 4 Sept 2026 at 13:56, Josua Mayer <josua@xxxxxxxxxxxxx> wrote:
> >> Add support for the SolidRun RZ/G2L SoM [1] on HummingBoard IIoT [2].
> >>
> >> The SoM features:
> >> - 2x 1Gbps Ethernet with PHY
> >> - eMMC
> >> - 1/2GB DDR
> >> - WiFi + Bluetooth
> >> - SDHI Mux switching between eMMC and Carrier Board
> >>
> >> The HummingBoard IIoT features:
> >> - 3x USB-2.0 Type A connector
> >> - 2x 1Gbps RJ45 Ethernet
> >> - USB Type-C Console Port
> >> - microSD connector
> >> - RTC with backup battery
> >> - RGB Status LED
> >> - 1x M.2 B-Key connector with USB-2.0 + SIM card holder
> >> - 1x DSI Display Connector
> >> - GPIO header
> >> - 2x RS232/RS485 ports (configurable)
> >> - 2x CAN
> >>
> >> Descriptions for eMMC, microSD and RS485 are provided as overlays due to
> >> their dependency on configurable mux states.
> >>
> >> [1] https://www.solid-run.com/embedded-industrial-iot/renesas-rz-family/rz-g2l-som/
> >> [2] https://www.solid-run.com/embedded-industrial-iot/renesas-rz-family/hummingboard-rz-series-sbcs/hummingboard-rz-g2l-iot-sbc/
> >>
> >> Signed-off-by: Josua Mayer <josua@xxxxxxxxxxxxx>
> > Thanks for your patch!
> >
> >> --- /dev/null
> >> +++ b/arch/arm64/boot/dts/renesas/rzg2l-hummingboard-iiot-common.dtsi
> >> +       aliases {
> >> +               gpio1 = &tca6408_u48;
> >> +               gpio2 = &tca6408_u37;
> >> +               gpio3 = &tca6416_u20;
> >> +               gpio4 = &tca6416_u21;
> > The TCA64xx driver does not seem to support gpio aliases,
> I have confirmed this now. My expectation was that setting gpio aliases
> helps make /dev/gpiochip numbering predictable, however this does
> not currently work.
> > so please
> > drop these.
> Is this a good reason to drop the aliases, or better to define them
> regardless?

Yes please.  Aliases are meant to identify labeled (numbered) connectors
on a device, e.g. first serial port is serial0.
A GPIO expander usually doesn't have such a connector, and the various
GPIOs are typically routed to a variety of places.

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