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

Frank Li Frank.li at nxp.com
Fri Oct 31 12:38:39 PDT 2025


On Wed, Oct 15, 2025 at 11:04:22AM +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#.
>
> 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 at nxp.com>
> ---

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



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