I was a bit quick when flashing my generic CC2652R and ended up dowloading and flashing firmware for CC2652P.. Since it was the wrong firmware, the bootloader also didn't work anymore, making me unable to flash the correct firmware with the integrated USB serial programmer.
Luckily the module has a cJTAG debugging interface, that should make it possible to flash directly onto the chip without the bootloader. But I don't have any serial debuggers, so I have had to come up withj my own from various limited information I could find.
Using OpenOCD we can use a Raspberry Pi as a JTAG debugger. It does not support cJTAG for debugging, so it will instead send a signal to make the CC2652 switch to normal JTAG. We will then have to connect a few additional cables to the TDO and TDI pins for a full 4-pin JTAG connection.