Enabling a Gadget CDC ACM Driver - How?

[Geary]

I'm trying to determine if the Android kernel will support a gadget
CDC ACM driver, and if so, how to go about the configuration. I'm also
wondering if any code changes will be required. Any advice would be
appreciated. Details are given below.

I'm working on an HTC Evo 4G. So I started off using the kernel source
from the HTC developer site. But when I compare their code in drivers/
usb/gadget to the AOSP code, I see a lot of differences. So the first
question is which should I use? I haven't been able to find anyway to
contact the HTC kernel team to ask any questions about their changes.
Is that even possible?

I've seen some info that shows how to enable KGDB, how to use enable
the serial port on the Nexus One, and I've read about PSFreedom and
how they implemented a gadget USB driver. Most of what I've seen says
to turn on CONFIG_USB_ANDROID_ACM, and turn off
CONFIG_MSM_SERIAL_DEBUGGER and CONFIG_MSM_FIQ_SUPPORT. And one other
said I needed to turn off HEADSET tags. Of course, PSFreedom wrote
their own driver.

I've tried a couple of kernel builds with the HTC source, and couldn't
get a Linux host to recognize the Android. The last config I tried had
only the ACM function of the Android gadget on. All other functions
were off. I just wanted to make sure it was trying to connect as an
ACM device. No luck.

I've also noticed, that, no matter how I configure, I always get the
dialog asking how I want to connect - Charge Only, etc. Is that
normal?

At this point, I'm planning to build a standard AOSP kernel with
config like the one described above. And see if that works. I hope I'm
not doing all of this for nothing - that some kernel will work as a
gadget CDC ACM device. Any information, advice or direction would be
appreciated.

Thanks