topic Re: Relation between USB_OTG_ID and /sys/kernel/debug/ci_hdrc.0/role in i.MX Processors

Relation between USB_OTG_ID and /sys/kernel/debug/ci_hdrc.0/role

yangao — Sun, 03 Apr 2022 03:18:03 GMT

Hi,

We are using iMX6 DL. On OTG port, we detected USB_OTG_ID is low but

~# cat /sys/kernel/debug/ci_hdrc.0/role
gadget

Is there something wrong?

I am thinking USB_OTG_ID being low means OTG port works as host and I can connect some USB device to it; while /sys/kernel/debug/ci_hdrc.0/role being "gadget" means the OTG port is working as gadget mode so I can only connect a host to it, right?

Regards,

Winston

Re: Relation between USB_OTG_ID and /sys/kernel/debug/ci_hdrc.0/role

AldoG — Wed, 06 Apr 2022 00:17:03 GMT

Hello,

Yes, your reasoning is correct, while the USB OTG ID pin is high/floating USB should be working as a device/gadget and when it is low it is working as a host.

Please check that you have configured correctly in your device tree this pin, you may refer to the following post:
https://community.nxp.com/t5/i-MX-Processors/USB-OTG-on-IMX6DL-detection-problem/m-p/766307

Best regards,
Aldo.

Re: Relation between USB_OTG_ID and /sys/kernel/debug/ci_hdrc.0/role

yangao — Fri, 08 Apr 2022 19:02:09 GMT

Thanks for the reply. There are some HW issue and HW re-design make the two match.

Regards,

Winston