USB CONNECT event and DISCONNECT event subscription

[Johan]

Hi,

I am looking for usb connect and disconnect events to be able to trigger some behaviors in our product.

I don't find any API for that, like subscribing via a callback to USB-events. It's kind of basic need for detecting USB-events.

Perhaps this isn't a Nordic question, but a zephyr one, but I thought why not ask if you guys have ideas or know anything.

I found events coming in into a callback in this driver: subsys/usb/class/cdc_acm.c

cdc_acm_do_cb () seems to get events and adding printing there, corresponds with me plugging and unplugging the usb cable.

PLUGGED:

<dbg> usb_cdc_acm.cdc_acm_do_cb: USB device connected

UNPLUG:

<inf> usb_cdc_acm: USB device suspended 

<inf> usb_cdc_acm: USB device disconnected 

Best,

[Johan]

I found the answer from the zephyr slack channel response.
I'll share it:

You can pass a status callback to usb_enable(), https://gist.github.com/jfischer-no/506c38ec81e7bf0118b423d0fcdaa0f3#file-diff The current stack was not designed for that,  therefore it is more a workaround as solution. I suggest to keep this status callback as short as possible and best to outsource the work into a thread (msq queue) or workqueue.

/Johan

[ovrebekk]

Hi Johan

Good to hear you found a solution, and thanks for sharing it 

I will consider the case resolved then.

Best regards
Torbjørn