AMD Patches To Generate DeviceTree Nodes For PCI Devices Merged In Linux 6.6

The DeviceTree changes for Linux 6.6 add the ability to generate DeviceTree (DT) nodes for PCI devices. AMD spearheaded this effort for applying DeviceTree overlays to PCI devices containing non-discoverable downstream devices.

Since last year AMD engineers have been working on these patches to allow generating DeviceTree nodes for PCI devices. This support allows for describing hardware peripherals that are present in a PCI endpoint but not auto-discoverable and for reusing of OF-compatible (Open Firmware) driver code typically used in a SoC platform but for a PCI-based system.

For AMD's purposes they appear to be interested in making use of this for their Xilinx Alveo FPGA-based accelerator cards. There is also a Microchip LAN9662 Ethernet controller driver that separately is also prepared to make use of this new DeviceTree functionality.

Over the past year this new DeviceTree functionality for PCI devices was revised several times and this week finally reached mainline. The DT pull request added the DT node generation for PCI devices as well as making several other core changes and updates to the growing number of DT bindings.