On Thu, Aug 19, 2021 at 03:52:55PM +0200, Nicolas Frattaroli wrote:

On Donnerstag, 19. August 2021 14:08:36 CEST Robin Murphy wrote:

quoted

quoted

+  rockchip,no-dmaengine:
+    description:
+      If present, driver will not register a pcm dmaengine, only the dai.
+      If the dai is part of multi-dais, the property should be present.
+    type: boolean

quoted

That sounds a lot more like a policy decision specific to the Linux
driver implementation, than something which really belongs in DT as a
description of the platform.

I agree. Should I be refactoring this into a module parameter or
something along those lines? I'm unsure of where this goes.

Why is this even required?  What is "multi-dais" and why would
registering the DMA stuff cause a problem?

The particular configuration may even vary per-board; an I2S/TDM
controller may be connected to an external codec which does not
support capture, whereas on another board it may be connected to
one that does.

If the external device doesn't support both directions then why does the
driver for the I2S controller in the CPU care?  The constraint handling
code in the core will ensure that nothing tries to start something that
isn't supported