OSS + ELC EU 2026

Over time, Pulse Width Modulators went from simple devices with only an input clock and a prescaler to more complex ones.
Nowadays, we can find PWM with several input clocks, several channels, shared and unshared prescalers among channels, and even bypasses which permits the PWM to act as a clock provider itself.

This talk covers a presentation of PMW basics, how to write a kernel driver with the new PWM waveform internal API.
Then, we will present a complex real life PWM device (Allwinner H616 PWM) and show how to leverage the power of the Common Clock Framework to help writing the kernel driver.
We'll continue with use cases of the H616 PWM internal bypass, which short-cuts the PWM logic and outputs a sine wave.
And finally, we'll show how to handle this bypass in the PWM driver and in the device tree.