Re: [PATCH v1] arm64: dts: rockchip: Enable PCIe CLKREQ# for RK3588 on Rock 5b-5bp-5t series

From: Shawn Lin <shawn.lin@rock-chips.com>
To: Anand Moon <linux.amoon@gmail.com>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Heiko Stuebner <heiko@sntech.de>, FUKAUMI Naoki <naoki@radxa.com>,
	Nicolas Frattaroli <nicolas.frattaroli@collabora.com>,
	Sebastian Reichel <sebastian.reichel@collabora.com>,
	Diederik de Haas <didi.debian@cknow.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	"moderated list:ARM/Rockchip SoC support"
	<linux-arm-kernel@lists.infradead.org>,
	"open list:ARM/Rockchip SoC support"
	<linux-rockchip@lists.infradead.org>,
	open list <linux-kernel@vger.kernel.org>
Cc: shawn.lin@rock-chips.com
Subject: Re: [PATCH v1] arm64: dts: rockchip: Enable PCIe CLKREQ# for RK3588 on Rock 5b-5bp-5t series
Date: Wed, 11 Mar 2026 20:26:38 +0800	[thread overview]
Message-ID: <cc922ebf-9221-00f8-e951-903c97d24f20@rock-chips.com> (raw)
In-Reply-To: <20260311115502.7353-1-linux.amoon@gmail.com>

在 2026/03/11 星期三 19:54, Anand Moon 写道:
> Add supports-clkreq and the corresponding pinmux configurations for PCIe
> ASPM L1 substates on the Rock 5B, 5B+, and 5T.
> The supports-clkreq flag informs the PCIe controller that the hardware
> routing for the CLKREQ# sideband signal is present. This enables support
> for PCIe ASPM (Active State Power Management) L1 substates, allowing for
> better power efficiency.
> 
> Cc: Shawn Lin <shawn.lin@rock-chips.com>
> Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> ---

It would be better if you could put the link to the schematic here(under
"---") for folks easy to review. I paste it here for reference：

https://dl.radxa.com/rock5/5b+/docs/hw/radxa_rock5bp_v1.2_schematic.pdf

>   arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi b/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
> index b3e76ad2d869..668b19c05f7e 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
> @@ -468,7 +468,8 @@ map1 {
>   
>   &pcie2x1l0 {
>   	pinctrl-names = "default";
> -	pinctrl-0 = <&pcie2_0_rst>;
> +	pinctrl-0 = <&pcie2_0_rst>, <&pcie30x1m1_0_clkreqn>;
> +	supports-clkreq;
>   	reset-gpios = <&gpio4 RK_PA5 GPIO_ACTIVE_HIGH>;
>   	vpcie3v3-supply = <&vcc3v3_pcie2x1l0>;
>   	status = "okay";
> @@ -476,7 +477,8 @@ &pcie2x1l0 {
>   
>   &pcie2x1l2 {
>   	pinctrl-names = "default";
> -	pinctrl-0 = <&pcie2_2_rst>;
> +	pinctrl-0 = <&pcie2_2_rst>, <&pcie20x1m0_clkreqn>;

Isn't it m1(PCIE20_1_2_CLKREQn_M1_L in the schematic)?

> +	supports-clkreq;
>   	reset-gpios = <&gpio3 RK_PB0 GPIO_ACTIVE_HIGH>;
>   	vpcie3v3-supply = <&vcc3v3_pcie2x1l2>;
>   	status = "okay";
> @@ -488,7 +490,8 @@ &pcie30phy {
>   
>   &pcie3x4 {
>   	pinctrl-names = "default";
> -	pinctrl-0 = <&pcie3_rst>;
> +	pinctrl-0 = <&pcie3_rst>, <&pcie30x4m1_clkreqn>;

The pin is correct but I don't think it would support
L1 substates because the refclk is out of control. For
any refclk coming from external clock generator, clkreq#
should connect to the enable pin of the clock generator.

> +	supports-clkreq;
>   	reset-gpios = <&gpio4 RK_PB6 GPIO_ACTIVE_HIGH>;
>   	vpcie3v3-supply = <&vcc3v3_pcie30>;
>   	status = "okay";
> 
> base-commit: b29fb8829bff243512bb8c8908fd39406f9fd4c3
> 