USB OTG not working as HOST

We have designed a custom carrier board for the jetson TX2 module.
we had a issue with the USB OTG not working as host.
after some research we got our problem solved by referring to this site
so we followed the steps given in the site and the OTG worked properly.

so my doubts are,

  1. what do you mean by GPIO regulators ?
  2. what changes do I need to do in my custom carrier board H/W design so that I don’t need to change the device tree.

in your TX2 adaptation guide(page 10), you have told to include vdd_usb2_5v supply to enable vbus-2-supply but I was not able to find the netnames anywhere in your schematics or any other document. so can you pls tell me what changes do I need to do in H/W so that we don’t need this device tree change

R.Rohith yadav

Hi, the pin P00 of U29 is a enable pin for M.2 Key E in P2597 and that is needed to enable USB2_DP/DM on M.2 Key E. So is the name given usb2_5v.

Hi Trumany,
In our design we have used USB0 signals for the USB OTG,
but the below change makes it work,

  • vbus-2-supply = <&vdd_usb2_5v>;
  • vbus-2-supply = <&battery_reg>;
    but this is for the USB2 signals, then why does it affect the USB0 singals.

R.Rohith yadav

Sw tries to configure the vbus-2 supply and it fails since the expander is not available.
So, to avoid sw to fail, vbus-2 is supplied with battery supply which is a fixed regulator with no constraints. SW happily enables this dummy regulator and proceed.

1 Like

Hi Trumany,
I have some question regarding this,

  1. Why does changing the Vbus-2-supply (which is the enable for USB2 signals) affect the working of USB0 signals
  2. I don’t have the expander on my custom carrier board, so can I change something H/W wise in my board. so that the USB0 work on my custom carrier board without any device tree change.

R.Rohith yadav

  1. Comment #4 already answered the question.
  2. Changing device tree is easier and safer than hw change as no such hw changes verified before.