title: How to check if UDC device supports isochronous transfer
body: <p>I have a UDC device under<code>/sys/class/udc</code>. I'd like to check if it supports isochronous transfers or not. There are several files with obvious names such as <code>is_otg</code>, <code>current_speed</code>, <code>maximum_speed</code>. But the rest seems cryptic. Is there any documentation maybe? Btw, I'm on <code>Android</code> and <code>is_otg</code> flag is 0, even though it must be otg. I've seen this on <code>Orange Pi One</code> too. Is this reliable anyway?</p>