Mainline kernel driver for eQEP

FYI, I just submitted a driver for the eQEP using the new counter subsystem if anyone is interested.

I would be curious to hear which features of the eQEP people are using.

Awesome David! I'll add it to our 5.3.x tree so users can start testing..


It should work on 5.2.x as well.

I am using a Rotary Encoder with the eQEP as an input device.
Initially I had a service that monitored sysfs changes to the count and injected right or left arrow keys based on the change.
But the existing eqep driver did not notify changes correctly and once I found the need to change it, I added the key injection into the driver itself.

I posted that here several months ago. I will look at your driver, the changes to use an RE as an input device are pretty simple.
Maybe some others find them useful.

With EduMIP[1] and Scuttle[2], we use just the relative position updates (per librobotics[3]), but I met someone who was using it for absolute positioning on a jewelry mill (based on stepper motors) and was using the index and strobe functions I don’t typically utilize. He said the homing could be far more accurate that way than we see with mechanical switch homing stops.