AM5728, PDK 1.0.2, Compiler V8.1.0, BIOS 184.108.40.206, XDC 3.32.0.06
Using the AM5728 on a custom board. A15 running Linux, DSP core running SYS/BIOS.
The desire is for the ARM to access GPIO banks 3,4,5 and DSP to access banks 6,8. The idea was the ARM and DSP would not ever access the same GPIO banks. The ARM would configure and use its banks and likewise for the DSP. However, we noticed that the DSP could not control its GPIO outputs unless we configured the pin for output in the Linux like this:
echo 235 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio235/direction
If I don't do that the DSP can't control the pin. If I do that then it works as expected.
BTW, the DSP is setting up the GPIO_v1_configDsp structure and calling GPIO_Init(); and setting up interrupt call backs which seem to work, so I'm baffled as to why those additional steps are required in Linux.