From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755458AbaFDGJn (ORCPT ); Wed, 4 Jun 2014 02:09:43 -0400 Received: from mout.gmx.net ([212.227.15.19]:62933 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755015AbaFDGJl (ORCPT ); Wed, 4 Jun 2014 02:09:41 -0400 Message-ID: <538EB81B.3090807@gmx.de> Date: Wed, 04 Jun 2014 08:09:31 +0200 From: Michael Lawnick User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Linus Walleij CC: Wolfram Sang , Grant Likely , Lee Jones , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-i2c@vger.kernel.org" Subject: Re: [PATCH] i2c: Make I2C ID tables non-mandatory for DT'ed and/or ACPI'ed devices References: <1401452797-29521-1-git-send-email-lee.jones@linaro.org> <1401452797-29521-2-git-send-email-lee.jones@linaro.org> <20140530123656.GC2742@katana> <20140530133405.GB29731@lee--X1> <20140530174800.GA4917@katana> <20140530192516.GA4319@lee--X1> <20140531134805.GA3287@katana> <538C8A59.2070907@gmx.de> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:Iggz67D/2mcWxfg/ETCsulL8DNWcIG+fFC2O+6ohdBKKYoUellV K6Dw/WSJJxkslyLc5VeUImcKinS/McD4kEvjtVyMkZ0lJ1jzMLjtPqTnycFg2nfN7RkunPg 6h1XdYDDZVv3cr/b/HGqEruVjwF+WbHXpGZzIoHg4uebRuPeOjd+5HdSbQRf2BspcJu0EUN xvu3DAF08aTIupvPbpPPg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 03.06.2014 13:18, schrieb Linus Walleij: > On Mon, Jun 2, 2014 at 4:29 PM, Michael Lawnick wrote: >> Am 02.06.2014 14:16, schrieb Linus Walleij: > >>> Is this really so useful on embedded systems? >>> >>> I was under the impression that this method was something used >>> on say PC desktops with temperature monitors and EEPROMs >>> on some I2C link on the PCB, usage entirely optional and fun >>> for userspace hacks. >>> >> We use it for dynamic instantiating whole subsystems with multiplexers, >> sensors, controllers in an embedded system. The device list is taken from an >> I2C eeprom which gets read on hotplug. > > Does this mean that you have stored the names (strings) that are used > by the Linux kernel for identifying the devices into your EEPROM? > > That means that you have made the kernel-internal device driver names > an ABI which is unfortunate :-/ > > This is one of the reasons to why we insist on device tree: OS neutral > hardware description. The eeprom contains a device tree that is dynamically merged. KR Michael