I2C in Linux 6.19 brought support for Rust-written I2C drivers. The newer I3C "Improved Inter-Integrated Circuit" interface changes have now been merged and the big feature there is HDR support. Not to be confused with the more common High Dynamic Range acronym usage for HDR, HDR in the I3C context is for the "High Data Rate" mode for facilitating faster data transfers.

I3C HDR allows for faster data rates while running at the same frequency as I3C SDR (Single Data Rate). With I3C SDR the top speed is around 12.5 Mbps while I3C HDR-DDR can allow up to 25 Mbps. The speeds can be pushed even further with alternate HDR modes like Ternary Symbol Pure (TSP) for leveraging multiple voltage levels of HDR Bulk Transport to make use of multiple data lines for speeds up to 100 Mbps.

NXP’s Frank Li has been working on the MIPI I3C HDR support for the Linux kernel in providing the necessary support and needed APU changes. A MEMSIC 3-axis magnetometer driver was written in the patch series for demonstrating use of the new I3C HDR API. As part of this I3C merge for Linux 6.19 is adapting the SVC driver for HDR use with NXP i.MX hardware.

Beyond introducing HDR transfer support, the only other notable work with the I3C pull for Linux 6.19 is adding Intel Nova Lake S support to the mipi-i3c-hci driver. Intel Linux engineers continue to be quite busy in readying the Linux kernel drivers for next-generation Nova Lake processors.