[PATCH v3 6/6] arm64: dts: rockchip: fix modem power supply topology on Photonicat

[Coia Prant]

The vcc3v4_rf regulator supplies the M.2 B-Key 5G modem. It was
incorrectly modeled as being supplied by vccin_5v (the external DC
input, before the main power switch).

Per the schematic, VCC3V4_RF is actually derived from VCC_SYSON (the
main system power rail after the power switch Q5013) via a ferrite
bead (B1).

Change the vin-supply of vcc3v4_rf to vcc_syson to accurately reflect
the hardware topology. While both vccin_5v and vcc_syson are
always-on fixed regulators without runtime GPIO control, this ensures
the DT power tree matches the schematic and traces the modem's power
path correctly. It also clarifies that the modem relies on the main
system rail rather than the external DC input directly.

Link: https://github.com/photonicat/photonicat-hardware/blob/main/Photonicat_rk3568_sch_20221116.pdf (Page 18)
Fixes: ba124e06ce7b ("arm64: dts: rockchip: add dts for Ariaboard Photonicat RK3568")
Signed-off-by: Coia Prant <coiaprant at gmail.com>
---
 arch/arm64/boot/dts/rockchip/rk3568-photonicat.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3568-photonicat.dts b/arch/arm64/boot/dts/rockchip/rk3568-photonicat.dts
index 290e3ee97c709..6ba70e5d9037e 100644
--- a/arch/arm64/boot/dts/rockchip/rk3568-photonicat.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3568-photonicat.dts
@@ -177,7 +177,7 @@ vcc3v4_rf: regulator-vcc3v4-rf {
 		regulator-name = "vcc3v4_rf";
 		regulator-min-microvolt = <3400000>;
 		regulator-max-microvolt = <3400000>;
-		vin-supply = <&vccin_5v>;
+		vin-supply = <&vcc_syson>;
 	};
 
 	vcc5v0_usb30_otg0: regulator-vcc5v0-usb30-otg0 {
-- 
2.47.3