While I was reviewing the target in depth I discovered that there is no support for the OTG on this target other than to put the chip to sleep. In effect the Media/Device port is unable to used at present. It is also limited to USB 1.1 speeds so it has limited utility outside of a few use cases that don't need high bandwidth to work well. Is this something that we want to support?
I also realized that there's a few problems with trying to support this chip, mostly to do with rockbox's architectural design. It generally only supports USB through a single port; either hardware controlled USB or software controlled through an OTG chip but not both on the same target. However the H300 is a weird hybrid. It includes 2 USB ports. One is for the OTG chip and then there's the hardware controlled port which does the UMS for this target and also allows charging over USB. So how would we support both in the same target given the architectural design?
I would like some thoughts from our users on whether this is something worth trying to implement or not. As for the use case, it would allow you to use the HID driver and possibly other drivers we haven't written yet. Some have been wanting to add USB Audio support which only needs USB 1.1.