Code size report:

   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
     mimxrt:    +0 +0.000% TEENSY40
        rp2:  +112 +0.012% RPI_PICO_W
       samd:    +0 +0.000% ADAFRUIT_ITSYBITSY_M4_EXPRESS
  qemu rv32:    +0 +0.000% VIRT_RV32

Following the pattern for shiftctrl, just after the edit. The single-line form is fine also but wanted to respect the style of the surrounding code.

I suspect the wrapped line below is because it hits some line length threshold, no need - afaik - to try and match that style since it's a functional choice and not a stylistic one (and also why I don't use strict code formatting).

Commit message should be something like:

rp2/rp2_pio: Add support for FIFO trigger level.

This is all a big magic-numbery for me but the datasheet - pages 329 and 377 at time of writing - seems to concur this is correct for RP2040.

It looks wrong for RP2350, though, the status_n field is four bits wide:

https://github.com/raspberrypi/pico-sdk/blob/ee68c78d0afae2b69c03ae1a72bf5cc267a2d94c/src/rp2350/hardware_structs/include/hardware/structs/pio.h#L44-L46

Instead of three:

https://github.com/raspberrypi/pico-sdk/blob/ee68c78d0afae2b69c03ae1a72bf5cc267a2d94c/src/rp2040/hardware_structs/include/hardware/structs/pio.h#L44-L46

Relevant snippet from the RP2350 datasheet:

Versus RP2040:

And the status_n field has also changed.

This code needs to handle the RP2350 case correctly. Not quite sure how to wrangle that.

In the interim anyone needing this feature can use machine.mem32[] with offsets 0x0cc, 0x0e4, 0x0fc, 0x114 (for SM0, SM1 ... etc) and base 0x50200000 or 0x50300000 for PIO0 and PIO1 respectively. Eg something like this (don't quote me 😆):

machine.mem32[0x50200000 | 0x0cc] &= ~0b1111                         # Mask out status_sel & status_n bits
machine.mem32[0x50200000 | 0x0cc] |= (status_sel << 4  | status_n)   # Set them to our desired values

RP2350 users can figure out the alternative.

Please try to make this work for RP2350. You could detect that chip using:

is_rp2350 = "RP2350" in sys.implementation._machine

Also, please update the documentation to add the new parameters.

I added support for both RP2040 and RP2350.