[PATCH] dts: riscv: spacemit: k3: Fix I/O power settings

[Yixun Lan]

SpacemiT K3 SoC support dual-voltage I/O power domain, while initially
configure to 3.3v, and need to access register from APBC space to switch
to 1.8v domain.

Fix the GMAC0's I/O pins 1.8v switch failure that will result a broken
ethernet driver.

Fixes: d8944577496b ("riscv: dts: spacemit: k3: add pinctrl support")
Reported-by: Han Gao <gaohan@xxxxxxxxxxx>
Signed-off-by: Yixun Lan <dlan@xxxxxxxxxx>
---
This issue is reported by Han while booting kernel from UFS storage, and
found the ethernet driver is broken, we can see the message as below:

 [    1.635881] mdio_bus stmmac-0: MDIO device at address 1 is missing.

This problem is caused by GMAC driver that unable to configure I/O power
domain to 1.8v, which leads to the MDIO communication failure.

We didn't find this problem due to using tftp(net) to load kernel images
while bootloader already configured the I/O power.
---
 arch/riscv/boot/dts/spacemit/k3.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/boot/dts/spacemit/k3.dtsi b/arch/riscv/boot/dts/spacemit/k3.dtsi
index 815debd16409..2b0bf9cd755b 100644
--- a/arch/riscv/boot/dts/spacemit/k3.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k3.dtsi
@@ -803,6 +803,7 @@ pinctrl: pinctrl@d401e000 {
 			clocks = <&syscon_apbc CLK_APBC_AIB>,
 				 <&syscon_apbc CLK_APBC_AIB_BUS>;
 			clock-names = "func", "bus";
+			spacemit,apbc = <&syscon_apbc>;
 		};
 
 		uart10: serial@d401f000 {

---
base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
change-id: 20260518-07-dts-pinctrl-io-power-1bd33bfe5894

Best regards,
--  
Yixun Lan <dlan@xxxxxxxxxx>