Re: [PATCH 13/26] ARM: omap3.dtsi: add omapdss information

On 2013-12-13 05:27, Laurent Pinchart wrote:

Hi Tony,

On Thursday 12 December 2013 21:59:13 Tony Lindgren wrote:

quoted

On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote:

quoted

On 2013-12-12 01:44, Laurent Pinchart wrote:

So, are they independent? I don't know =). I think they lean on the
independent side. dss_core is always needed for the submodules to work,
but for example DSI could be used without DISPC, using system DMA to
transfer data from memory to DSI. Not a very useful thing to do, but
still, there are dedicated DMA channels for that.

If they have separate hwmod entries, they should be considered separate
independent devices for sure.

To summarize, here are few reasons why they need to be treated as
separate devices:

Are you talking generally here, or about the DSS modules in particular ?

quoted

1. The modules maybe clocked/powered/idled separately and can have their
   own idle configuration so they can do the hardware based idling
   separately.

I don't think this applies to the DSS modules.

The DSS submodules have their own SYSCONFIG register, and idle settings
can be set per module. So I think they idle separately, even if they are
in a common power domain.

 Tomi