From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 10 Jan 2008 14:49:19 +1100 From: David Gibson To: Timur Tabi , Jon Smirl , Liam Girdwood , alsa-devel@alsa-project.org, linuxppc-dev@ozlabs.org Subject: Re: [alsa-devel] [PATCH] ASoC drivers for the Freescale MPC8610 SoC Message-ID: <20080110034919.GI17816@localhost.localdomain> References: <9e4733910801010925j67192427o4e0e824b9d7e0ad0@mail.gmail.com> <9e4733910801010942y47e4cdbfge5e0d3e44ab96760@mail.gmail.com> <477BAB67.4080003@freescale.com> <9e4733910801020734n115888cbt86351f67f2311629@mail.gmail.com> <477D2150.4020506@freescale.com> <20080103235156.GE12883@localhost.localdomain> <477EEDFA.9010205@freescale.com> <20080106004637.GJ4326@localhost.localdomain> <47824AA3.5070808@freescale.com> <20080107182853.GA17312@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20080107182853.GA17312@sirena.org.uk> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jan 07, 2008 at 06:28:54PM +0000, Mark Brown wrote: > On Mon, Jan 07, 2008 at 09:52:03AM -0600, Timur Tabi wrote: > > David Gibson wrote: > > > > Ok, but couldn't you strucutre your I2S or fabric driver so that it > > > only becomes fully operational once the codec driver has registered > > > with it? > > > Not in ASoC V1. You have to understand, ASoC V1 was designed without any > > consideration for runtime-bindings and other OF goodies. All connections > > between the drivers are static, literally. In fact, I wouldn't be surprised if > > some ASoC drivers cannot be compiled as modules. > > I'd just like to emphasise this point - ASoC v1 really doesn't > understand the idea that the components of the sound subsystem might be > probed separately. It's set up to handle bare hardware with everything > being probed from code in the machine/fabric driver. This makes life > very messy for platforms with something like the device tree. > > As has been said, handling this properly is one of the major motivations > behind ASoC v2. Ick. Ok. Nonetheless, messing up the device tree to workaround ASoC V1's silly limitations is not a good idea. The device tree must represent the hardware as much as possible. If that means we have to have a bunch of platform-specific hacks to instatiate the drivers in the correct order / combination, that's unfortunate, but there you go. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson