From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8CE2C43460 for ; Fri, 9 Apr 2021 07:56:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B878D611B0 for ; Fri, 9 Apr 2021 07:56:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232432AbhDIH4Z (ORCPT ); Fri, 9 Apr 2021 03:56:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:48160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232060AbhDIH4X (ORCPT ); Fri, 9 Apr 2021 03:56:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A500D611BE; Fri, 9 Apr 2021 07:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617954970; bh=g5uN6Pl+84n19Wf10nEdkopoOYV20QI0EjR4ZGbc7jw=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=u2BbVFCGWc0iS4ph2dc5d1nDl187zG5P9pXL1Cm6UOvWXL3L0dBEsKrg9/h1POc19 h1WrlG2N5RR70AfSyZdWdMlRfjSGxKElfDb2SekhNnbfeKF4rnj6bxkOif0Ar50QQN L8FOwMyG1mXV7kTv/r2whQZMJUOhdTOYVDxPMGm6ArRqHL3EPwgc0LK+44RK7rTaEo QtrxjBMbCvXDQloY7nyKYEsuVDzznNlhD0KJKBz6g7AEXPQ+O+gkf4K5ostmrJzQXT Ao9W8Dtp2lp0FyPZk/qIJzxaOuEHjUxNrPcTk6TwRCsXKnPbtf7wW4aI220hiiVUBS iOtE6CzaWBe6Q== Received: by mail-ot1-f43.google.com with SMTP id c24-20020a9d6c980000b02902662e210895so4871507otr.9; Fri, 09 Apr 2021 00:56:10 -0700 (PDT) X-Gm-Message-State: AOAM533wqrDde4EzYCMRg7e5KTjTRx1/w++3Ha+pEjFrIcSEOZ1h+CHZ lnaaGkQHSE4W/ziTuOS2o46325t3o/c07NGzehg= X-Google-Smtp-Source: ABdhPJyqkLL/YHm17TDMQcZw+JH1/6IOKmDcxX4k29Ovd57mDpReYbYM6BJUI+r5hcy0H4zXnuBQh0qM5jt0HH/0Mc4= X-Received: by 2002:a05:6830:148c:: with SMTP id s12mr11539093otq.251.1617954970003; Fri, 09 Apr 2021 00:56:10 -0700 (PDT) MIME-Version: 1.0 References: <20210319062752.145730-1-andrew@aj.id.au> <20210319062752.145730-16-andrew@aj.id.au> In-Reply-To: <20210319062752.145730-16-andrew@aj.id.au> From: Arnd Bergmann Date: Fri, 9 Apr 2021 09:55:53 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 16/21] ipmi: kcs_bmc: Add a "raw" character device interface To: Andrew Jeffery Cc: openipmi-developer@lists.sourceforge.net, OpenBMC Maillist , Corey Minyard , Joel Stanley , Ryan Chen , DTML , Tomer Maimon , linux-aspeed , "open list:GPIO SUBSYSTEM" , Avi Fishman , Patrick Venture , Linus Walleij , Linux Kernel Mailing List , Tali Perry , Rob Herring , Lee Jones , chiawei_wang@aspeedtech.com, Linux ARM , Benjamin Fair Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 19, 2021 at 7:31 AM Andrew Jeffery 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