arm64: dts: imx8mq-evk: Add supports-clkreq property to PCIe M.2 port

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>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
index a88bc9034663..852992b915a3 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
@@ -375,6 +375,7 @@
 		 <&clk IMX8MQ_CLK_PCIE1_PHY>,
 		 <&clk IMX8MQ_CLK_PCIE1_AUX>;
 	vph-supply = <&vgen5_reg>;
+	supports-clkreq;
 	status = "okay";
 };
 
@@ -398,6 +399,7 @@
 		 <&clk IMX8MQ_CLK_PCIE2_AUX>;
 	vpcie-supply = <&reg_pcie1>;
 	vph-supply = <&vgen5_reg>;
+	supports-clkreq;
 	status = "okay";
 };