Re: DT DMA channel binding for Tegra I2S

Mark,

On 11/25/2011 10:09 AM, Mark Brown wrote:

On Fri, Nov 25, 2011 at 09:55:23AM -0600, Rob Herring wrote:

quoted

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