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References: <20210319062752.145730-1-andrew@aj.id.au> <20210319062752.145730-16-andrew@aj.id.au>
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From:   Arnd Bergmann <arnd@kernel.org>
Date:   Fri, 9 Apr 2021 09:55:53 +0200
Message-ID: <CAK8P3a1HDQdbTAT4aRMLu-VFz720ynPqPHG5b22NZ5p5QfUqOw@mail.gmail.com>
Subject: Re: [PATCH v2 16/21] ipmi: kcs_bmc: Add a "raw" character device interface
To:     Andrew Jeffery <andrew@aj.id.au>
Cc:     openipmi-developer@lists.sourceforge.net,
        OpenBMC Maillist <openbmc@lists.ozlabs.org>,
        Corey Minyard <minyard@acm.org>, Joel Stanley <joel@jms.id.au>,
        Ryan Chen <ryan_chen@aspeedtech.com>,
        DTML <devicetree@vger.kernel.org>,
        Tomer Maimon <tmaimon77@gmail.com>,
        linux-aspeed <linux-aspeed@lists.ozlabs.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Avi Fishman <avifishman70@gmail.com>,
        Patrick Venture <venture@google.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Tali Perry <tali.perry1@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Lee Jones <lee.jones@linaro.org>, chiawei_wang@aspeedtech.com,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Benjamin Fair <benjaminfair@google.com>
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On Fri, Mar 19, 2021 at 7:31 AM Andrew Jeffery <andrew@aj.id.au> 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