[PATCH v6 06/11] arm64: dts: imx8qm-mek: Add supports-clkreq property to PCIe M.2 port
Frank Li
Frank.li at nxp.com
Fri Oct 31 12:39:52 PDT 2025
On Wed, Oct 15, 2025 at 11:04:23AM +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#.
>
> imx8qm-mek 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>
shawn: I posted it as richard at imx8qm dts patches, you can pick this one
with other part together.
> arch/arm64/boot/dts/freescale/imx8qm-mek.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8qm-mek.dts b/arch/arm64/boot/dts/freescale/imx8qm-mek.dts
> index 202d5c67ac40b..c1e4775c13849 100644
> --- a/arch/arm64/boot/dts/freescale/imx8qm-mek.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8qm-mek.dts
> @@ -775,6 +775,7 @@ &pciea {
> pinctrl-names = "default";
> reset-gpio = <&lsio_gpio4 29 GPIO_ACTIVE_LOW>;
> vpcie-supply = <®_pciea>;
> + supports-clkreq;
> status = "okay";
> };
>
> --
> 2.37.1
>
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