Re: [PATCH 0/9] Serial slave device bus

From: Arnd Bergmann
Date: Fri Jan 06 2017 - 14:26:31 EST


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