The I3C Subsystem Won't Be Added For Linux 4.20 / 5.0

While there was a push by its developers to align the I3C subsystem code for the next kernel, it's not going to happen for Linux 4.20.

I3C is the sensor interface specification introduced in 2017 as an improvement over I2C by combining the best aspects of it with the SPI and UART specifications while making the standard suitable for IoT devices.

The Linux I3C infrastructure code went through nine rounds of public review and has been worked on for more than one year, but not in time for this current development cycle.

When inquiring about getting the I3C framework merged, Greg Kroah-Hartman interjected that were sent too late in the cycle that he wasn't going to review them until after this merge window.

Those wanting to learn more about the I3C sensor specification can do so at MIPI.org.