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

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* Tomi Valkeinen <tomi.valkeinen@xxxxxx> [131213 02:19]:
> On 2013-12-13 05:27, Laurent Pinchart wrote:
> > Hi Tony,
> > 
> > On Thursday 12 December 2013 21:59:13 Tony Lindgren wrote:
> >> On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote:
> >>> 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 ?
> > 
> >> 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.

Yes. Please see the current omap_hwmod_*_data.c files, if they are separate
entries there, that means we need to treat them as separate devices to
avoid the issues I listed.

We do have some entries still missing from omap_hwmod_*_data.c files, like
the SSI entries as they are undocumented. But for the existing ones there
please follow the same layout for the .dts entries.

Regards,

Tony
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