OTG USB port in Orange Pi PC2, role switch

Hi all

After having used a lot the OPiPC2 with Armbian, I am now adding support for this board in openwrt.

The first add board patch, has been merged recently in snapshot branch and works ok.

For the first implementation I set the MUSB port role to host, but now my goal is to set it in OTG, making this port available for usb serial console, connecting a host PC to it.

So, I built the needed support for g_serial in kernel and give a try, but I cannot make it work

The host PC detects just nothing, as the OpiPC2 does not detect a USB host being connected to it

Checking the dmesg I see something suspicious:

[    0.614423] sun4i-usb-phy 1c19400.phy: Couldn't request ID GPIO

The only gpio managed by this USB phy (that is the one attached to the MUSB 1c19000) is the role switch PIN, as far as I understand:

usb0_id_det-gpios = <&pio 6 12 GPIO_ACTIVE_HIGH>; /* PG12 */

The dts are the mailine ones of kernel 4.14.x, the OTG support for H5 has been added in 4.12.x but I think I remember that I had the same dmesg log also in Armbian (I run it till 4.15.x)

PG12 is not taken by other nodes, so I really don't understand the problem here, IF this is a problem and not a warning that I shall just ignore

Thanks, bye