Hi Rob,

Here goes another attempt at a serial device bus (aka uart slaves, tty
slaves, etc.).

After some discussions with Dmitry at LPC, I decided to move away from
extending serio and moved back to making a new bus type instead. He didn't
think using serio was a good fit, and serio has a number of peculiarities
in regards to sysfs and it's driver model. I don't think we want to inherit
those for serial slave devices.

This version sits on top of tty_port rather than uart_port as Alan
requested. Once I created a struct tty rather than moving everything
needed to tty_port, it became a lot easier and less invasive to the tty
core code.

I have hacked up versions of the BT ldisc and TI ST drivers moved over to
use the serdev bus. I have BT working on the HiKey board which has TI BT.
With the serdev bus support, it eliminates the need for the TI userspace
UIM daemon.

thanks for looking at the TI ST driver. That thing has been a thorn in my eyes for years. It has been such a hack job and I wanted to get rid of the double line disciplines for a long time now. Even using HCI line discipline as we have to day would be way better than dealing with the UIM daemon. The hacked around issues that have been solved cleanly in the Bluetooth subsystem.

Regards

Marcel