[PATCH v3] arm64: dts: rockchip: rock-3b: Model PI6C20100 as gated-fixed-clock

[Jonas Karlman]

Hi,

On 3/19/2026 11:22 AM, MidG971 wrote:
> The Radxa ROCK 3B uses a PI6C20100 PCIe reference clock buffer to
> provide a 100MHz reference clock to the PCIe 3.0 PHY and controllers.
> This chip is currently modeled only as a fixed regulator
> (vcc3v3_pi6c_03), with no clock output representation.
> 
> The PI6C20100 is a clock generator, not a power supply. Model it
> properly as a gated-fixed-clock, following the pattern established
> for the Rock 5 ITX and other boards with similar PCIe clock buffer
> chips.
> 
> The regulator node is kept as-is since it controls the power supply
> to the PI6C20100 chip via GPIO0_D4. The new gated-fixed-clock node
> references this regulator as its vdd-supply and provides a proper
> 100MHz clock output. The pcie3x2 node is updated to include the
> pipe and reference clocks, matching the approach used in
> rk3588-rock-5-itx.dts.
> 
> Assisted-by: Claude:claude-3-opus
> Signed-off-by: MidG971 <midgy971 at gmail.com>

Typically you should use your real name in SoB line, kernel docs state:

  using a known identity (sorry, no anonymous contributions.)

https://docs.kernel.org/process/submitting-patches.html

> ---
> 
> Changes since v2 [1]:
>  - Fix AI attribution: use Assisted-by tag instead of Signed-off-by (Shawn)
>  - Add missing pipe clock (CLK_PCIE30X2_PIPE_DFT) to pcie3x2 clocks
>    override (Shawn, referencing David's patch [2])
> 
> Changes since v1 [3]:
>  - Drop phy-supply approach entirely (Jonas, Shawn)
>  - Model PI6C20100 as gated-fixed-clock instead
>  - Wire reference clock to pcie3x2 controller
>  - Follow pattern from rk3588-rock-5-itx.dts
> 
> [1] https://lore.kernel.org/linux-rockchip/20260304132957.684616-1-midgy971@gmail.com/
> [2] https://lore.kernel.org/linux-rockchip/d981fa84-bd05-ac9d-98ca-89ee47177829@rock-chips.com/T/#m6a8289609e6a60691d3c06358b6322c7aa5e43d1
> [3] https://lore.kernel.org/linux-rockchip/20260213151452.535527-1-midgy971@gmail.com/
> 
>  arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
> index c5f67dd6dfd9..1a2b3c4d5e6f 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
> @@ -56,7 +56,16 @@
>  		};
>  	};
> 
> -	/* pi6c pcie clock generator */
> +	/* PI6C20100 PCIe reference clock buffer (100MHz) */
> +	pcie30_refclk: pcie-clock-generator {
> +		compatible = "gated-fixed-clock";
> +		#clock-cells = <0>;
> +		clock-frequency = <100000000>;
> +		clock-output-names = "pcie30_refclk";
> +		vdd-supply = <&vcc3v3_pi6c_03>;

The vcc3v3_pi6c_03 regulator should also be removed in this patch,
as you state in the commit message, it is not a power supply.

Please convert to use enable-gpios prop.

Regards,
Jonas

> +	};
> +
> +	/* PI6C20100 power supply - active-high GPIO0_D4 */
>  	vcc3v3_pi6c_03: regulator-3v3-vcc-pi6c-03 {
>  		compatible = "regulator-fixed";
>  		enable-active-high;
> @@ -553,6 +562,15 @@
>  };
> 
>  &pcie3x2 {
> +	clocks = <&cru ACLK_PCIE30X2_MST>, <&cru ACLK_PCIE30X2_SLV>,
> +		 <&cru ACLK_PCIE30X2_DBI>, <&cru PCLK_PCIE30X2>,
> +		 <&cru CLK_PCIE30X2_AUX_NDFT>,
> +		 <&cru CLK_PCIE30X2_PIPE_DFT>,
> +		 <&pcie30_refclk>;
> +	clock-names = "aclk_mst", "aclk_slv",
> +		      "aclk_dbi", "pclk", "aux",
> +		      "pipe", "ref";
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&pcie30x2m1_pins>;
>  	reset-gpios = <&gpio2 RK_PD6 GPIO_ACTIVE_HIGH>;
> --
> 2.39.5
>