Add I3C support and an I3C bus alias to the rzg3e-smarc-som.dtsi.
This enables support for I3C devices on the R9A09G047E57 SMARC SoM
and prepares for future expansion.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
 arch/arm64/boot/dts/renesas/rzg3e-smarc-som.dtsi | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/renesas/rzg3e-smarc-som.dtsi b/arch/arm64/boot/dts/renesas/rzg3e-smarc-som.dtsi
index 7faa44510d98..dce5cf3bd841 100644
--- a/arch/arm64/boot/dts/renesas/rzg3e-smarc-som.dtsi
+++ b/arch/arm64/boot/dts/renesas/rzg3e-smarc-som.dtsi
@@ -29,6 +29,7 @@ aliases {
 		ethernet0 = &eth0;
 		ethernet1 = &eth1;
 		i2c2 = &i2c2;
+		i2c9 = &i3c;
 		mmc0 = &sdhi0;
 		mmc2 = &sdhi2;
 	};
@@ -122,6 +123,12 @@ raa215300: pmic@12 {
 	};
 };
 
+&i3c {
+	pinctrl-0 = <&i3c_pins>;
+	pinctrl-names = "default";
+	status = "disabled";
+};
+
 &mdio0 {
 	phy0: ethernet-phy@7 {
 		compatible = "ethernet-phy-id0022.1640",
@@ -219,6 +226,12 @@ i2c2_pins: i2c {
 			 <RZG3E_PORT_PINMUX(3, 5, 1)>; /* SDA2 */
 	};
 
+	i3c_pins: i3c {
+		pinmux = <RZG3E_PORT_PINMUX(2, 0, 2)>, /* I3C0_SCL */
+			 <RZG3E_PORT_PINMUX(2, 1, 2)>; /* I3C0_SDA */
+		drive-push-pull;
+	};
+
 	rtc_irq_pin: rtc-irq {
 		pins = "PS1";
 		bias-pull-up;
-- 
2.43.0

Hi Tommaso,

> @@ -29,6 +29,7 @@ aliases {
>  		ethernet0 = &eth0;
>  		ethernet1 = &eth1;
>  		i2c2 = &i2c2;
> +		i2c9 = &i3c;

Hmmm, I am quite sure the i3c bus is not named i2c9 in the datasheets?
I'd suggest to drop this line.

Rest LGTM.

Happy hacking,

   Wolfram

Hi Wolfram,
Thank you for your review!

On Tue, Nov 18, 2025 at 05:34:07PM +0100, Wolfram Sang wrote:
> Hi Tommaso,
> 
> > @@ -29,6 +29,7 @@ aliases {
> >  		ethernet0 = &eth0;
> >  		ethernet1 = &eth1;
> >  		i2c2 = &i2c2;
> > +		i2c9 = &i3c;
> 
> Hmmm, I am quite sure the i3c bus is not named i2c9 in the datasheets?
> I'd suggest to drop this line.
> 
> Rest LGTM.

Ack. Will drop this in v2.

> 
> Happy hacking,
> 
>    Wolfram
> 

Thanks & Regards,
Tommaso