How to `pruss_get()` both PRUSS on AM5728

I’m working on a driver that requires both PRU subsystems (all four PRU cores) on the AM5728. Looking at the kernel source, it appears impossible to specify more than one PRUSS in the device tree for this platform driver. This really puts me in a bind.

  1. Can anyone recommend a reasonable workaround? It doesn’t have to pretty.
  2. Is there an inherent reason for this limitation, or did no one anticipate this scenario?