From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: Date: Wed, 24 Oct 2007 09:54:09 -0600 From: "Grant Likely" Sender: glikely@secretlab.ca To: "Timur Tabi" Subject: Re: Audio codec device tree entries In-Reply-To: <471F6761.3030405@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <9e4733910710221859q6ea54810nba58907d5ddd966d@mail.gmail.com> <471E12C7.8020509@freescale.com> <8416ea754e013a67441aec778c81ad73@kernel.crashing.org> <9e4733910710231529h1089eacdy888306f20af92555@mail.gmail.com> <471F52ED.10007@freescale.com> <9e4733910710240800y24952e70g8c318e35e2e45e2e@mail.gmail.com> <9e4733910710240823v2022661ftb1b754a86cab88f3@mail.gmail.com> <471F6761.3030405@freescale.com> Cc: PowerPC dev list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 10/24/07, Timur Tabi wrote: > Jon Smirl wrote: > > > I see your point about putting the child node onto the control bus. > > ac97 is both a control and data bus. For the i2s case the child should > > go onto the i2c bus. > > I know AC97 is *also* a control bus, but treating I2S and AC97 differently is > bad, IMHO. If you're going to put the child node in the AC97 node, you should > also put it in the I2S node. They *are* different. The choice you're making is whether or not you keep them similar in the control path or the data path; but you still have to choose. > > The 8610 has an SSI that can operate as either AC97 or I2S. If I want to switch > from AC97 to I2S, I should not have to move the child node out of the AC97 node. > I should instead just add an I2C node and point to it. But you need a different codec node regardless. The board/system will in the vast majority of cases designed to only use AC97 or only use I2S. It's not moving a node. It's deleting an ac97 codec node and adding an i2s codec node. Besides; correctness is more important that how many device tree changes need to be made to go from one board design to another. Cheers, g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. grant.likely@secretlab.ca (403) 399-0195