Forum TI-Planet.org

I want to make a host controller driver for the TI-Nspire CX, but I have encountered a roadblock:
After resetting the controller, I want to enable the power on the USB port.
I tried the normal EHCI way of setting the port power bit in the PORTSC register, but it just hangs. It doesn't just hang normally, not even IRQs are working.
I looked at the linux driver for the chipidea USB controller, and they enable the port power through a regulator, not in the PORTSC register.
I also tried setting the output of GPIO2 to 0, like on hackspire, but it also didn't help.

But there has to be a way, since I dumped the PORTSC register after I attached a USB device, and the controller was in host mode and port power enabled.
The strange thing is that when the controller was in host mode with port power enabled and is then reset, the port power stays on, so it doesn't seem like the USB controller is actually controlling it.
Also setting the power to on works when the calculator was connected to TI-Connect before running.

Does anyone have another idea?

AFAIK it's controlled over GPIOs: https://hackspire.org/index.php?title=GPIO_Pins

The Linux device tree confirme that: https://github.com/torvalds/linux/blob/ ... cx.dts#L73

How did you mesure that it's indeed outputting 5V? Did GPIO20 indicate that something is plugged in?