TMC2209 with SKR 2.0 using software serial now appears broken

[fitch22]

I have finally returned to my CNC project and built latest code for BTT SKR 2.0 with TMC2209. It appears the software serial code no longer works, or I need to configure something else that I am not aware of. The last build I made was 1/24/2022 and that works.

I took a quick look at the new tmc_uart.c file and compared it to the code from btt_skr_2.0.c where it used to be. I found a couple things that looked to be issues but I have been unsuccessful fixing them. I am trying to avoid pulling out my scope to look at the comms:-).

The status in iosender does not show a TMC in NEWOPT the way it did last year. But it does show Trinamic as a PLUGIN. My old firmware shows TMC=7. I cant do a M122 or M122I since the comm doesnt work.

I am happy to help resolve this, but need a starting point. There are a lot of changes to the code that I was not a part of.

Thanks!