From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.250]) by ozlabs.org (Postfix) with ESMTP id DCB1ADE1C0 for ; Fri, 4 Jan 2008 05:25:46 +1100 (EST) Received: by an-out-0708.google.com with SMTP id c37so1147734anc.78 for ; Thu, 03 Jan 2008 10:25:45 -0800 (PST) Message-ID: Date: Thu, 3 Jan 2008 11:25:45 -0700 From: "Grant Likely" Sender: glikely@secretlab.ca To: "Timur Tabi" Subject: Re: [PATCH] ASoC drivers for the Freescale MPC8610 SoC In-Reply-To: <477D25F4.6020700@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <11981089894052-git-send-email-timur@freescale.com> <9e4733910801012027p4be16b92r43af773f4e5ae531@mail.gmail.com> <477BADF5.9060003@freescale.com> <477D25F4.6020700@freescale.com> Cc: linuxppc-dev@ozlabs.org, alsa-devel@alsa-project.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 1/3/08, Timur Tabi wrote: > Grant Likely wrote: > > > Does that mean with ASoC V2 you can instantiate it with the board > > specific platform code instead? > > I don't know. I haven't really looked at V2 yet. You'll have to ask Liam > Girdwood. > > > This is one of the examples of where the compatible properties are > > trying to be far to generic about what they are. How do you define > > what "fsl,ssi" is? > > The SSI is a specific Freescale device, so I think it's pretty well defined. > > > What happens when Freescale produces another > > peripheral that can do ssi but isn't register level compatible? > > It won't be called the SSI. It will be called something else. Heh, I've seen enough to know that it's virtually impossible for a company to maintain a consistent naming scheme all the time. Better to be specific now and add generic names sometime in the future rather than the other way around. > > In my opinion, it is far better to be specific in the device tree and > > teach the driver about what versions it is able to bind against. In > > this case, I would use "fsl,mpc8610-ssi" or maybe better yet: > > "fsl,mpc8610-ssi,i2s" (MPC8610 SSI device in I2S mode). > > I can work with that, but the SSI could be placed into any future 83xx, 85xx, > or 86xx SOC, and the driver will still work with it as-is. The have the device trees claim compatibility with the older fsl,mpc8610-ssi device specifically. ie: compatible = "fsl,mpc83-ssi,ac97", "fsl,mpc8610-ssi,ac97"; > > > I don't like the idea of a separate fsl,mode property to describe the > > behaviour of multifunction peripherals. It makes probing more > > difficult when there is a different driver for each mode. > > Can you propose an alternative? The driver needs to know what mode to use > when communicating with its codec. How am I supposed to know if I have an I2S > codec or an AC97 codec? Make the compatible property tell you! :-) If it's connected to an I2S codec, then it could be compatible = "fsl,mpc8610-ssi,i2s". Or for AC7, compatible = "fsl,mpc8610-ssi,ac97" Cheers, g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. grant.likely@secretlab.ca (403) 399-0195