Allwinner D1/D1s Platform Support Moves Closer To Mainline Linux

The D1 is Allwinner's first SoC based on a RISC-V core design. While the Allwinner D1 isn't powerful at all, it's appearance in low-cost boards, RISC-V based design, and the Allwinner development community has made this an attractive entry-level RISC-V target. While various Linux distributions are already supporting D1-based boards, the mainline support for the D1/D1s platform looks like it will finally be merged in 2023.

As one of the last kernel patch series posted for 2022, the v4 revision of the Allwinner D1/D1s platform enablement was posted. This platform enablement has the build configuration updates, new DeviceTree files, and gets features working like USB, Ethernet, and WiFi that have already been worked on and merged as part of prior patches. The Allwinner D1s is very similar to the D1 but has 64MB of memory onboard the package, lacks HDMI output, and drops the DSP.

With this Allwinner D1/D1s platform support comes the DeviceTree for bringing up the ClockworkPi, Dongshan Nezha STU, MangoPi MQ, MangoPi MQ Pro, and Sipeed Lichee RV boards using this SoC. Many of these are lower-cost RISC-V boards but again there isn't much to the performance side with it being a single-core RISC-V processor around 1GHz and fabbed on a 22nm process.

Lichee RV

From the sounds of it in the patch message, this D1/D1s platform support is about ready for mainline and gives hope that it will all be squared away in time for Linux 6.3:

"I thoroughly tested earlier versions of this series (DMIC, Ethernet, LEDs, MMC, PMIC, touch, and USB, where available) on several boards. v4 has only trivial changes, and I boot-tested it on sun20i-d1-nezha.

This series is pretty much just waiting on the regulator binding to land. I do not expect to send another version. For the rest of the hardware blocks, DT additions will be based on top of this series."