On Friday, January 6, 2017 10:26:26 AM CET Rob Herring wrote:

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.

Using serio was originally my idea, but since you seem to have discussed
this in more detail than I ever had, the new version is certainly fine with
me too.

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.

This series and the mentioned drivers can be found here[1].

I took a quick look at the series and have no immediate concerns,
just one detail about the DT binding that seems odd to me.

	Arnd