Re: [PATCH v2] arm64: dts: rockchip: Add missing pinctrl for PCIe30x4 node

[Chen-Yu Tsai <wens@kernel.org>]

On Thu, Jul 11, 2024 at 4:44 PM Jonas Karlman <jonas@kwiboo.se> wrote:
>
> Hi Anand,
>
> On 2024-07-11 08:09, Anand Moon wrote:
> > Add missing pinctrl settings for PCIe 3.0 x4 clock request and wake
> > signals.Each component of PCIe communication have the following control
> > signals: PERST, WAKE, CLKREQ, and REFCLK. These signals work to generate
> > high-speed signals and communicate with other PCIe devices.
> > Used by root complex to endpoint depending on the power state.
> >
> > PERST is referred to as a fundamental reset. PERST should be held low
> > until all the power rails in the system and the reference clock are stable.
> > A transition from low to high in this signal usually indicates the
> > beginning of link initialization.
> >
> > WAKE signal is an active-low signal that is used to return the PCIe
> > interface to an active state when in a low-power state.
> >
> > CLKREQ signal is also an active-low signal and is used to request the
> > reference clock.
> >
> > Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> > ---
> > V2: Update the commit messge to describe the changs.
> >     use pinctl group as its pre define in pinctl dtsi
> > ---
> >  arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts | 6 +-----
> >  1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts b/arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts
> > index 2e7512676b7e..ab3a20986c6a 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts
> > +++ b/arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts
> > @@ -301,7 +301,7 @@ &pcie30phy {
> >
> >  &pcie3x4 {
> >       pinctrl-names = "default";
> > -     pinctrl-0 = <&pcie3_rst>;
> > +     pinctrl-0 = <&pcie30x4m1_pins>;
>
> Use of the existing pcie30x4m1_pins group may not be fully accurate for
> the PERST pin. The use of reset-gpios indicate that the PERST pin is
> used with GPIO function and the driver will implicitly change the
> function from perstn_m1 to GPIO. So this may not be best representation
> of the hw, hence my initial suggestion, something like:
>
>         pcie30x4_pins: pcie30x4-pins {
>                 rockchip,pins =
>                         <4 RK_PB4 4 &pcfg_pull_none>,
>                         <4 RK_PB6 RK_FUNC_GPIO &pcfg_pull_none>,
>                         <4 RK_PB5 4 &pcfg_pull_none>;
>         };
>
> Similar change should probably also be done for pcie2x1l0 and pcie2x1l2,
> not just pcie3x4.

Can we consider implementing strict mode in the pinctrl driver so we don't
have to keep doing this GPIO + pinmux dance?

ChenYu


> Regards,
> Jonas
>
> >       reset-gpios = <&gpio4 RK_PB6 GPIO_ACTIVE_HIGH>;
> >       vpcie3v3-supply = <&vcc3v3_pcie30>;
> >       status = "okay";
> > @@ -341,10 +341,6 @@ pcie2_2_rst: pcie2-2-rst {
> >       };
> >
> >       pcie3 {
> > -             pcie3_rst: pcie3-rst {
> > -                     rockchip,pins = <4 RK_PB6 RK_FUNC_GPIO &pcfg_pull_none>;
> > -             };
> > -
> >               pcie3_vcc3v3_en: pcie3-vcc3v3-en {
> >                       rockchip,pins = <1 RK_PA4 RK_FUNC_GPIO &pcfg_pull_none>;
> >               };
> >
> > base-commit: 34afb82a3c67f869267a26f593b6f8fc6bf35905
>
>