Andrea della Porta from SUSE is working hard to bring Raspberry Pi 5 support to the mainline Linux kernel. Over the past few months, he has posted several patches. These patches partially rely on Raspberry Pi’s downstream kernel code. His latest focus is on upstreaming support for the Raspberry Pi RP1 PCI device using a DeviceTree overlay.
The Role of RP1 in Raspberry Pi 5 #
This features the RP1, an in-house I/O controller and chipset. This chipset handles many key functions like camera input, display output, USB 2 and USB 3, video output, and Gigabit Ethernet MAC. The RP1 chipset is central to the overall functionality of this single-board computer.
Andrea’s Work on RP1 Support #
Andrea recently shared new patches to upstream support for the RP1 chipset. He described RP1 as an MFD (Multi-Function Device) chipset. It acts as a south-bridge PCIe endpoint with subdevices like Ethernet, USB controllers, I2C, and PWM. These devices, connected to the RP1 endpoint, are not discoverable through standard PCI enumeration. Instead, they must be declared via DeviceTree.
Andrea’s patchset aims to create basic infrastructure for RP1 recognition. It also seeks to add its peripherals using a DeviceTree overlay during the RP1 PCI endpoint enumeration. This work builds on downstream driver code and proposals from other contributors.
Challenges: Dependencies and Delays #
These patches rely on BCM2712 PCIe controller patches, which are not yet up streamed. With the Raspberry Pi 5’s one-year anniversary in October, full mainline kernel support is still pending. Despite progress, challenges remain.
Conclusion #
Andrea della Porta’s work is crucial for integrating Raspberry Pi 5 support into the mainline Linux kernel. While hurdles remain, the efforts of SUSE and the broader Linux community highlight a strong commitment to improving the Raspberry Pi experience.
