From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: DT DMA channel binding for Tegra I2S Date: Sat, 26 Nov 2011 22:07:01 -0600 Message-ID: <4ED1B765.9070107@gmail.com> References: <74CDBE0F657A3D45AFBB94109FB122FF174F08C803@HQMAIL01.nvidia.com> <4ECD6BA4.1010607@gmail.com> <74CDBE0F657A3D45AFBB94109FB122FF174F08C881@HQMAIL01.nvidia.com> <20111125160908.GF5315@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20111125160908.GF5315-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown Cc: Stephen Warren , "Grant Likely (grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org)" , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: devicetree@vger.kernel.org Mark, On 11/25/2011 10:09 AM, Mark Brown wrote: > On Fri, Nov 25, 2011 at 09:55:23AM -0600, Rob Herring wrote: > >> Although, I think you are possibly missing some other properties for >> i2s mode like word size and master/slave mode. I think the ideal case >> is that a single ASoC platform driver for DT could handle multiple >> SoCs. > > No. You're not going to be able to get a single binding which handles > the setup for all systems based off a given SoC let alone multiple SoCs. > It is possible to come up with some subsets which work over multiple > boards but that's going to be outside the binding for the I2S controller > and in a board audio hardware binding for the subset. I never said a single binding. Part of device tree is describing how devices are connected together which is a large part of the audio configuration. Whether there's one common driver or not doesn't really matter. The important part right now is to define the bindings and do so in a common way where possible. My original point really was that when defining a binding, it should be as complete as possible rather than done incrementally over time. You are describing the h/w, and that's not changing. For an i2s block, only having a dma channel is definitely not complete. > This has been discussed repeatedly, we really need to work out how to > educate device tree people about this stuff, it gets *very* repetitive > having the discussion over and over again. As you might guess, audio is not an area I have been spending time on recently. Perhaps seeing a complete binding with all the pieces (codec, i2s, misc gpio's, etc.) would help educate us. Rob