[PATCH 4/5] arm64: dts: rockchip: add the PCIe power domain to the RK3588 PCIe SMMU

[Arun Iyengar via B4 Relay]

From: Arun Iyengar <aiyengar1990 at gmail.com>

The MMU-600 for the PCIe controllers (mmu600_pcie) is enabled for every
RK3588 board, but its node does not describe that it lives in
RK3588_PD_PCIE. It only works today because TF-A leaves the domain on at
boot and, on most boards, an enabled PCIe controller holds it on later.

On a board that disables all PCIe controllers using that domain (the
Orange Pi 5 with its M.2 slot in SATA mode is one), genpd powers
PD_PCIE off as unused after boot while arm-smmu-v3 is still bound. Then
at reboot arm_smmu_device_shutdown() writes CR0 and polls CR0ACK on the
unpowered block, which stalls the bus: the kernel never reaches
"reboot: Restarting system" and the board only comes back once the
watchdog fires.

Describe the power domain, so genpd keeps it on for as long as the SMMU
is bound.

Fixes: da92d3dfc871 ("arm64: dts: rockchip: enable the mmu600_pcie IOMMU on the rk3588 SoC")
Signed-off-by: Arun Iyengar <aiyengar1990 at gmail.com>
---
 arch/arm64/boot/dts/rockchip/rk3588-base.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi b/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi
index aa69fd3793fd..bcd342c025c9 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3588-base.dtsi
@@ -560,6 +560,7 @@ mmu600_pcie: iommu at fc900000 {
 			     <GIC_SPI 367 IRQ_TYPE_EDGE_RISING 0>;
 		interrupt-names = "eventq", "gerror", "priq", "cmdq-sync";
 		#iommu-cells = <1>;
+		power-domains = <&power RK3588_PD_PCIE>;
 	};
 
 	mmu600_php: iommu at fcb00000 {

-- 
2.55.0