USB detection on Linux Embedded

[nstjean]

Hi,
On a phyCORE-AM335x running Linux, I am trying to detect when USB cable is connect and disconnect. Is there a way to handle interrupt or event on USB from withing a main application?

I noticed that the interrupt count in /proc/interrupt for "musb-hdrc.0" increases when cable is connect/disconnected.

Yet, I have tried using libudev, without success.

A message is displayed on terminal when connecting and disconnecting USB cable between PC and board.
"[...] musb Haptic controller gadget disconnected" and "[...] Haptic Controller: high-speed #1: 2mA, Haptic controller [...] Haptic Controller: Using interface 0"

Any advice or comment will be appreciated
Thanks

[Jan Axelson]

Maybe this will help:

http://unix.stackexchange.com/questions/28548/how-to-run-custom-scripts-upon-usb-device-plug-in

[nstjean]

Thanks Jan,

This link gave me hints, but, I did not manage to trig an event when connecting and disconnecting the usb cable. When I run "udevadm monitor", there is no event displayed upon cable connection or disconnection.

On my setup, the phyCore is the device, and I wish to detect when the PC (host) is connected or not. The detection is on the phyCORE side (linux embedded).

I have also been looking for a detection of the power USB from PC, found nothing yet.

[Jan Axelson]

What will the device do with the information?

Typically, a device learns of attach/detach by detecting the presence/absence of VBUS.

[nstjean]

The idea is to know when to open and close the handle on the USB device, depending of existing link or not between device and PC.

[Jan Axelson]

Some ideas here:

https://e2e.ti.com/support/embedded/linux/f/354/t/65332