As far as I understand, the QCS610 devkit has at least four different kinds of GPIOs:
PM6150L, PM6150 and LPI GPIO, and normal GPIOs. Can somebody explain to me how and when to use them? Or is there a document with a good documentation that I might have missed?
What I think I understood (I am using a Linux system):
1. In /sys/kernel/debug/gpio, I can see three different gpiochips: gpiochip0 for controlling normal GPIOs, gpiochip1 for pm6150l, gpiochip2 for pm6150. I tried to export the pm6150l gpio9, but I got the following error:
[email protected]:/sys/class/gpio# echo 1270 > export sh: write error: Device or resource busy
2. Is the LPI only connected to the DSP? We would very much like to use the UART it provides, to communicate with peripherals. Is that possible? In the dts files, I can see the line compatible = "qcom,lpi-pinctrl", but there does not seem to be any driver that handles this compatible string?