Re: [PATCH v6 00/10] Add support for RaspberryPi RP1 PCI device using a DT overlay

Andrew Lunn
2025-02-13T16:27:02Z

On Thu, Feb 13, 2025 at 05:14:35PM +0100, Herve Codina wrote:
> Hi Phil,
>
> On Thu, 13 Feb 2025 15:18:45 +0000
> Phil Elwell <phil@raspberrypi.com> wrote:
>
> > Hi Andrea,
> >
> > The problem with this approach (loading an overlay from the RP1 PCIe
> > driver), and it's one that I have raised with you offline, is that
> > (unless anyone can prove otherwise) it becomes impossible to create a
> > Pi 5 DTS file which makes use of the RP1's resources. How do you
> > declare something as simple as a button wired to an RP1 GPIO, or fan
> > connected to a PWM output?

Where is this button or fan? On a pluggable board? Isn't that what
overlays are for, and they are stackable. So when you probe the
pluggable board via its eeprom etc, you find the overlay and load it?

Or do you mean a custom board, which has a CPU, RP1 and the button and
fan are directly on this custom board? You then want a board DTS which
includes all these pieces?

Andrew