[PATCH v6 05/11] arm64: dts: imx8mq-evk: Add supports-clkreq property to PCIe M.2 port

Richard Zhu
2025-10-15T03:05:34Z

According to PCIe r6.1, sec 5.5.1.

The following rules define how the L1.1 and L1.2 substates are entered:
Both the Upstream and Downstream Ports must monitor the logical state of
the CLKREQ# signal.

Typical implement is using open drain, which connect RC's clkreq# to
EP's clkreq# together and pull up clkreq#.

imx8mq-evk matches this requirement, so add supports-clkreq to allow
PCIe device enter ASPM L1 Sub-State.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mq-evk.dts | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
index a88bc90346636..852992b915a39 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
@@ -375,6 +375,7 @@ &pcie0 {
<&clk IMX8MQ_CLK_PCIE1_PHY>,
<&clk IMX8MQ_CLK_PCIE1_AUX>;
vph-supply = <&vgen5_reg>;
+ supports-clkreq;
status = "okay";
};

@@ -398,6 +399,7 @@ &pcie1 {
<&clk IMX8MQ_CLK_PCIE2_AUX>;
vpcie-supply = <&reg_pcie1>;
vph-supply = <&vgen5_reg>;
+ supports-clkreq;
status = "okay";
};

--
2.37.1