From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932640AbaEEN5G (ORCPT ); Mon, 5 May 2014 09:57:06 -0400 Received: from top.free-electrons.com ([176.31.233.9]:37837 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932395AbaEEN5E (ORCPT ); Mon, 5 May 2014 09:57:04 -0400 Date: Mon, 5 May 2014 15:57:02 +0200 From: Alexandre Belloni To: Geert Uytterhoeven Cc: Maxime Ripard , Mark Brown , linux-spi , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] spi: Force the registration of the spidev devices Message-ID: <20140505135701.GA21940@piout.net> References: <1398705774-12361-1-git-send-email-maxime.ripard@free-electrons.com> <20140429183758.GH15125@sirena.org.uk> <20140430180609.GC3000@lukather> <20140501011811.GF3245@sirena.org.uk> <20140501223629.GJ3000@lukather> <20140505041721.GD11606@lukather> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/05/2014 at 09:10:43 +0200, Geert Uytterhoeven wrote : > Hi Maxime, > > On Mon, May 5, 2014 at 6:17 AM, Maxime Ripard > wrote: > > On Fri, May 02, 2014 at 01:28:26AM +0200, Geert Uytterhoeven wrote: > >> On Fri, May 2, 2014 at 12:36 AM, Maxime Ripard > >> wrote: > >> > But it actually doesn't work in a case where you can't really predict > >> > what is on the other side of the bus. Either because, on the board > >> > you're using the pins are exposed and it's pretty much up to the user > >> > to know what to put on it. That could be handled by DT overlays > >> > though. > >> > > >> > What never works is where the device on the other side is so generic > >> > that you really can't tell what it does. Think of a microcontroller > >> > that would behave as a SPI slave. It's behaviour and what it does is > >> > pretty much dependant of what we flashed on it, and suddenly the > >> > compatible string is not the proper reprensentation anymore. > >> > >> So you will (hopefully soon) use overlay DT to change the DTS to match what's > >> connected? > > > > Not really, because you can't declare a spidev device in the DT. > > Yes you can. I've done it before. > > See also "git grep -w spidev -- arch/arm/*/dts/". > I'm pretty sure that doesn't work as there is no compatible matching "spidev" My guess would be that you added it in spidev.c -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com