[PATCH v6 04/11] arm64: dts: imx8mp-evk: Add supports-clkreq property to PCIe M.2 port

Frank Li Frank.li at nxp.com
Fri Oct 31 12:38:16 PDT 2025


On Wed, Oct 15, 2025 at 11:04:21AM +0800, Richard Zhu wrote:
> 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#.
>
> imx8mp-evk matches this requirement, so add supports-clkreq to allow
> PCIe device enter ASPM L1 Sub-State.
>
> Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li at nxp.com>

>  arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
> index 3730792daf501..523bf4aeff317 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
> @@ -710,6 +710,7 @@ &pcie0 {
>  	pinctrl-0 = <&pinctrl_pcie0>;
>  	reset-gpio = <&gpio2 7 GPIO_ACTIVE_LOW>;
>  	vpcie-supply = <&reg_pcie0>;
> +	supports-clkreq;
>  	status = "okay";
>  };
>
> --
> 2.37.1
>



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