I'm afraid I don't have an answer -- but I have to comment that your
query itself (and subject line) is somewhat misleading. Especially as you
state "configuration of the ADC of the Beaglebone AI" -- since the BBAI
(and BBB) have built-in on-board ADC capability which CAN be accessed from
the PRU (and lots of hits in Google on just that)
However, your mention of an STMPE811 (the datasheet calls it an "8-bit
port expander with advanced touchscreen controller") indicates that
specifying ADC is a red-herring. Your REAL question becomes:
PRU - I2C on BBAI
Given the date, this
https://github.com/chanakya-vc/PRU-I2C_SPI_master/wiki is BBB related. It
also appears to be an attempt to use the PRU as an additional I2C (or SPI)
master -- the PRU implementing the communication protocol via
"bit-banging"; not having the PRU access the native I2C of the SoC.
The closest I've found for having a PRU command the system I2C is
https://groups.google.com/forum/#!topic/beagleboard/QjjoNglpJ8s and a
school project at
<http://iis-projects.ee.ethz.ch/index.php/Control_an_external_ADC_using_Programmable_Real-Time_Unit_(PRU)_Subsystem_on_Beaglebone_Black_used_as_embedded_HPC-performance-monitoring_device>
which appears to still be looking for a student to do the implementation
"""
Status: Available
Looking for 1 Master Students (Semester Project)
"""
(If it has been worked, the results appear to not be available openly)
Remember, the full name for the PRU is PRU-ICSS, and the ICSS part is
"industrial communication sub-system" -- ie; one writes the communication
protocol to run /on/ the PRU.