Hi Heiko,
Thanks for your review comments.
On Wed, 10 Jul 2024 at 20:24, Heiko Stübner <heiko@xxxxxxxxx> wrote:
>
> Hi,
>
> Am Mittwoch, 10. Juli 2024, 16:19:56 CEST schrieb Anand Moon:
> > Add missing pinctrl settings for PCIe 3.0 x4 clock request and wake
> > signals. Rename node from 'pcie3' to 'pcie30x4' to align with schematic
> > nomenclature.
> >
> > Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
> > ---
> > .../boot/dts/rockchip/rk3588-rock-5b.dts | 20 +++++++++++++------
> > 1 file changed, 14 insertions(+), 6 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..a9b55b7996cf 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 = <&pcie30x4_perstn_m1 &pcie30x4_clkreqn_m1 &pcie30x4_waken_m1>;
> > reset-gpios = <&gpio4 RK_PB6 GPIO_ACTIVE_HIGH>;
> > vpcie3v3-supply = <&vcc3v3_pcie30>;
> > status = "okay";
> > @@ -340,14 +340,22 @@ pcie2_2_rst: pcie2-2-rst {
> > };
> > };
> >
> > - pcie3 {
> > - pcie3_rst: pcie3-rst {
> > - rockchip,pins = <4 RK_PB6 RK_FUNC_GPIO &pcfg_pull_none>;
> > - };
> > -
> > + pcie30x4 {
> > pcie3_vcc3v3_en: pcie3-vcc3v3-en {
> > rockchip,pins = <1 RK_PA4 RK_FUNC_GPIO &pcfg_pull_none>;
> > };
> > +
> > + pcie30x4_clkreqn_m1: pcie30x4-clkreqn-m1 {
> > + rockchip,pins = <4 RK_PB4 RK_FUNC_GPIO &pcfg_pull_up>;
> > + };
> > +
> > + pcie30x4_waken_m1: pcie30x4-waken-m1 {
> > + rockchip,pins = <4 RK_PB5 RK_FUNC_GPIO &pcfg_pull_down>;
> > + };
> > +
> > + pcie30x4_perstn_m1: pcie30x4-perstn-m1 {
> > + rockchip,pins = <4 RK_PB6 RK_FUNC_GPIO &pcfg_pull_down>;
> > + };
>
> I'm not sure what you're going for here, but defining them as gpio makes
> them essentially unused? Shouldn't they go to the pcie controller?
>
Ok, Each component of PCIe communication to have the following
control signals #PERST # WAKE and CLKREQ from root complex to endpoint.
> From what I found for example
> The PERST# signal is used to indicate when the power supply is within its specified voltage tolerance and is stable.
>
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.
> At least you'll need to explain more in the commit message.
>
Ok,
WAKE and CLKREQ signals are used to transition to and from low-power states.
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.
>
I will work on and update in the next version.
>
> Heiko
Thanks
-Anand
