[PATCH v2 3/3] arm64: dts: rockchip: fix the pcie refclock oscillator on Rock 5 ITX

[Heiko Stübner]

Am Donnerstag, 18. Juli 2024, 10:00:51 CEST schrieb Anand Moon:
> Hi Dragan
> 
> On Thu, 18 Jul 2024 at 13:28, Dragan Simic <dsimic at manjaro.org> wrote:
> >
> > On 2024-07-18 09:52, Anand Moon wrote:
> > > On Thu, 18 Jul 2024 at 13:02, Dragan Simic <dsimic at manjaro.org> wrote:
> > >> On 2024-07-18 09:26, Anand Moon wrote:
> > >> > On Mon, 15 Jul 2024 at 16:35, Heiko Stuebner <heiko at sntech.de> wrote:
> > >> >>
> > >> >> The Rock 5 ITX uses two PCIe controllers to drive both a M.2 slot and
> > >> >> its
> > >> >> SATA controller with 2 lanes each. The supply for the refclk
> > >> >> oscillator is
> > >> >> the same that supplies the M.2 slot, but the SATA controller port is
> > >> >> supplied by a different rail.
> > >> >>
> > >> >> This leads to the effect that if the PCIe30x4 controller for the M.2
> > >> >> probes first, everything works normally. But if the PCIe30x2
> > >> >> controller
> > >> >> that is connected to the SATA controller probes first, it will hang on
> > >> >> the first DBI read as nothing will have enabled the refclock before.
> > >> >
> > >> > I just checked the rk3588-rock-5-itx.dts in the linux-next.
> > >> > You have not enabled sata0 and sata2, which might be the problem
> > >> > for the SATA controller not getting initialized.
> > >>
> > >> Rock 5 ITX doesn't use RK5588's built-in SATA interfaces, so that's
> > >> fine.
> > >> Please have a look at the board schematic, it uses a separate PCI
> > >> Express
> > >> SATA controller for its four SATA ports.
> > >>
> > > yes, But I am referring to sata node not enabled which enable
> > > the PHY_TYPE_SATA.
> > >
> > > see rk3588-coolpi-cm5-evb.dts and rk3588-edgeble-neu6a-io.dtsi
> > > rk3588-quartzpro64.dts
> > > which have sata port on board.
> > >
> > > &sata0 {
> > >         status = "okay";
> > > };
> >
> > QuartzPro64, as an example, uses RK3588's built-in SATA interfaces,
> > so it enables sata0 in its board dts.  Rock 5 ITX doesn't do that,
> > as I already described.
> 
> Ok no problem,

For the Rock 5 ITX it really only routes 2 PCIe lanes to one M.2 port
and the other 2 lanes to the separate ASMedia SATA controller.
So from the Rock5 PoV, it's really just 2 PCIe 2-lane slots and the
SATA controller simply gets probed as PCIe device.

I even have a sample of the Rock 5+ here, that actually drops the
separate SATA controller and instead provides a 2nd M.2 slot ;-)

Heiko