USB patch for rpi4

[Peter Robinson]

> > > I am trying to test v4 of your patch series for USB support on rpi4:
> > > https://patchwork.ozlabs.org/project/uboot/list/?series=179078
> > >
> > > I am building u-boot 64-bit.  Testing on a rpi4 B 1.2 board.  But, USB is
> > > not working for me and wanted to see if you had any ideas.  Are there
> > > other dependencies other than just applying your patch series?
> > >
> > > I've pasted the u-boot console output below.
> > >
> > > From what I can tell this board does not need the VL805 firmware
> >
> > 1.2 rev boards do need the firmware loading patch series, not sure
> > about any other patches.
>
> Are you sure?  A colleague of mine said that it was in 1.4 that the flash
> chip for the VL805 was removed.  I can physically see that the flash
> chip is on my board.

Yes, I am sure, the 1.2 is for the 2/4Gb model with the changes that
need the firmware loading, the 1.4 according to their rev docs is
limited to the 8Gb model ATM.

https://www.raspberrypi.org/documentation/hardware/raspberrypi/revision-codes/README.md

>
> In any case, I did figure out one thing that was going on.  I was using
> the rpi4 DTB as it came shipped with my board.  I found that on the
> PCIe node there was a typo in the compatible string.  I fixed that:
>                         bus-range = <0x0 0x1>;
> -                       compatible = "brcm,bcm7211-pcie",
> "brcm,bcm7445-pcie", "brcm,pci-plat-dev";
> +                       compatible = "brcm,bcm2711-pcie",
> "brcm,bcm7445-pcie", "brcm,pci-plat-dev";
>                         max-link-speed = <0x2>;
>
> ...and USB now starts up and works.
>
> Thanks,
> Stuart