Re: [PATCH v2 16/21] ipmi: kcs_bmc: Add a "raw" character device interface

From: Arnd Bergmann
Date: Fri Apr 09 2021 - 03:56:14 EST


On Fri, Mar 19, 2021 at 7:31 AM Andrew Jeffery <andrew@xxxxxxxx> wrote:
>
> The existing IPMI chardev encodes IPMI behaviours as the name suggests.
> However, KCS devices are useful beyond IPMI (or keyboards), as they
> provide a means to generate IRQs and exchange arbitrary data between a
> BMC and its host system.

I only noticed the series after Joel asked about the DT changes on the arm
side. One question though:

How does this related to the drivers/input/serio/ framework that also talks
to the keyboard controller for things that are not keyboards? Are these
separate communication channels on adjacent I/O ports, or does there
need to be some arbitration?

Arnd