Re: [PATCH v2 7/8] arm64: dts: qcom: sm8350: add PCIe devices

[Johan Hovold <johan@kernel.org>]

On Thu, Nov 10, 2022 at 05:20:11PM +0300, Dmitry Baryshkov wrote:
> On 10/11/2022 13:53, Johan Hovold wrote:
> > On Thu, Nov 10, 2022 at 01:33:44PM +0300, Dmitry Baryshkov wrote:
> >> Add PCIe0 and PCIe1 (and corresponding PHY) devices found on SM8350
> >> platform. The PCIe0 is a 1-lane Gen3 host, PCIe1 is a 2-lane Gen3 host.
> >>
> >> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >> ---
> >>   arch/arm64/boot/dts/qcom/sm8350.dtsi | 246 ++++++++++++++++++++++++++-
> >>   1 file changed, 244 insertions(+), 2 deletions(-)
> > 
> >> @@ -1761,6 +1957,52 @@ tlmm: pinctrl@f100000 {
> >>   			gpio-ranges = <&tlmm 0 0 204>;
> >>   			wakeup-parent = <&pdc>;
> >>   
> >> +			pcie0_default_state: pcie0-default-state {
> >> +				perst-pins {
> >> +					pins = "gpio94";
> >> +					function = "gpio";
> >> +					drive-strength = <2>;
> >> +					bias-pull-down;
> >> +				};
> >> +
> >> +				clkreq-pins {
> >> +					pins = "gpio95";
> >> +					function = "pcie0_clkreqn";
> >> +					drive-strength = <2>;
> >> +					bias-pull-up;
> >> +				};
> >> +
> >> +				wake-pins {
> >> +					pins = "gpio96";
> >> +					function = "gpio";
> >> +					drive-strength = <2>;
> >> +					bias-pull-up;
> >> +				};
> >> +			};
> > 
> > The pinconfig should go in the board file.
> 
> Usually yes. However for the PCIe we usually put them into the main 
> .dtsi. See sm8[124]50.dtsi.

Yeah, I noticed that too and had this discussion with Bjorn for
sc8280xp some months ago. Even if you may save a few lines by providing
defaults in a dtsi, the pin configuration is board specific and belongs
in the dts.

Also note that 'perst' and 'wake' above could in principle be connected
to other GPIOs on different boards.

Johan