A13 issues with OTG on kernel 6.16

[Franco Palombo]

Hi, I'm working on a small tablet that uses the A13 processor. I'm in the process of making the wiki page on linux-sunxi.org (check out here)

So far I was able to compile and boot u-boot from the sdcard port. Video works, usb devices get detected and I can interact with it via serial, so I dont think there is any issue there (only thing that I can't verify if works its the mmc).

I was also able to compile mainline Linux 6.16 and successfully boot it using an arch linux rootfs (with a few errors here and there, but booting ok). I got video, and serial, but no usb otg. I know for sure that something about usb works because the internal wifi usb adapter gets detected.

I've tested a few things that I think are useful:

- when dr_mode=host, with externally supplied +5v, devices get detected and listed.
- with dr_mode=host and reg_usb0_vbus with the property "regulator-always-on", devices get detected without the need for external +5v.
- with dr_mode=otg, i can see that something is aware about the state of the usb port because:
[root@alarm extcon0]# cat /sys/class/extcon/*/state #nothing
USB=0
USB-HOST=0
[root@alarm extcon0]# cat /sys/class/extcon/*/state #charger
USB=1
USB-HOST=0
[root@alarm extcon0]# cat /sys/class/extcon/*/state #otg cable
USB=0
USB-HOST=1

I attached my .config, device tree and dmesg output. I've really have no idea on where to poke now