On Thu, 13 Feb 2025 16:30:44 +0000 Phil Elwell <phil@xxxxxxxxxxxxxxx> wrote: > Hi Andrew, > > On Thu, 13 Feb 2025 at 16:27, Andrew Lunn <andrew@xxxxxxx> wrote: > > > > 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@xxxxxxxxxxxxxxx> 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? > > In the Raspberry Pi ecosystem it would be the firmware that applies > the overlay, and it can't do that if the resources the overlay refers > to are not yet present in the dtb. What do you mean by the 'the resources are not yet present in the dtb' ? Also what you call the 'firmware' is the bootloader ? the kernel ? Can you tell me who is the 'firmware' what is the mecanisme it uses to load the overlay. Best regards, Hervé > > > 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? > > That depends on whether you count the Raspberry Pi 5 as a custom board. >
