Hi James, On Sat, Jun 01, 2024 at 10:36:13PM +0100, James Dutton wrote: > Hi, > > Is there any way to capture the USB-PD protocol messages on the CC > pins of a usb connection? > > I can use "modprobe usbmod" to capture the URB messages. > Is there any way to capture the CC pin messages using in negotiation > power USB-PD. Unfortunately there is no way to capture the USB PD messages. The operating system is not in control of the USB PD communcation in most cases. Instead, there is a dedicate component called PD controller that handles the communnication. The PD controllers often only give some status information about connections and limited control over the connectors. > I guess is association with this, some way of also capturing the > Volts/Current on the Vconn and Vbus pins. The information that we can read from the PD controllers is exposed to the user space using the USB Type-C connector device class and USB Power Delivery device class. You should see the PDO details under /sys/class/usb_power_devivery if they are available. The connectors, and the partner devices attached to them, are exposed under /sys/class/typec > If it helps, my cpu is an AMD 7840, so it will be using whatever USB > hubs come with that. Br, -- heikki
