Re: [PATCH v5 4/4] arm64: dts: qcom: qcs615-ride: Enable PCIe interface

[Ziyue Zhang]

On 6/18/2025 12:33 AM, Manivannan Sadhasivam wrote:
> On Tue, May 27, 2025 at 03:20:36PM +0800, Ziyue Zhang wrote:
> > From: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> >
> > Add platform configurations in devicetree for PCIe, board related
> > gpios, PMIC regulators, etc.
> >
> > Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> > Signed-off-by: Ziyue Zhang <quic_ziyuzhan@xxxxxxxxxxx>
> > ---
> >   arch/arm64/boot/dts/qcom/qcs615-ride.dts | 42 ++++++++++++++++++++++++
> >   1 file changed, 42 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/qcs615-ride.dts b/arch/arm64/boot/dts/qcom/qcs615-ride.dts
> > index 2b5aa3c66867..c59647e5f2d6 100644
> > --- a/arch/arm64/boot/dts/qcom/qcs615-ride.dts
> > +++ b/arch/arm64/boot/dts/qcom/qcs615-ride.dts
> > @@ -217,6 +217,23 @@ &gcc {
> >   		 <&sleep_clk>;
> >   };
> >   
> > +&pcie {
> > +	perst-gpios = <&tlmm 101 GPIO_ACTIVE_LOW>;
> > +	wake-gpios = <&tlmm 100 GPIO_ACTIVE_HIGH>;
> > +
> > +	pinctrl-0 = <&pcie_default_state>;
> > +	pinctrl-names = "default";
> > +
> > +	status = "okay";
> > +};
> > +
> > +&pcie_phy {
> > +	vdda-phy-supply = <&vreg_l5a>;
> > +	vdda-pll-supply = <&vreg_l12a>;
> > +
> > +	status = "okay";
> > +};
> > +
> >   &pm8150_gpios {
> >   	usb2_en: usb2-en-state {
> >   		pins = "gpio10";
> > @@ -244,6 +261,31 @@ &rpmhcc {
> >   	clocks = <&xo_board_clk>;
> >   };
> >   
> > +&tlmm {
> > +	pcie_default_state: pcie-default-state {
> > +		clkreq-pins {
> > +			pins = "gpio90";
> > +			function = "pcie_clk_req";
> > +			drive-strength = <2>;
> > +			bias-pull-up;
> > +		};
> > +
> > +		perst-pins {
> > +			pins = "gpio101";
> > +			function = "gpio";
> > +			drive-strength = <2>;
> > +			bias-pull-down;
> Are you sure that the default state of the pin should be 'pull down'? Pull down
> of a PERST# is deassert, which should only happen once the power and refclk are
> stable.
>
> - Mani

Hi Mani,

pull-down is assert, we need to make sure perset is asserted before refclk is
stable.

BRs
Ziyue