How complete should the DTS be?

David Gibson david at
Thu Jan 10 14:13:31 EST 2008

On Tue, Jan 08, 2008 at 12:04:36AM -0600, Kumar Gala wrote:
> On Jan 7, 2008, at 8:07 PM, Sean MacLennan wrote:
> > Just a general question about DTS "completeness". Like all 440EP
> > processors, the taco has two i2c buses. However, only one bus has
> > anything connected to it.
> >
> > Should I show both bus entries in the DTS, or only the one that is  
> > used?
> > I have generally only been showing the devices that are present. i.e.
> > Only one emac, only one serial port.
> >
> > Is there a convention for this?
> The .dts should reflect the HW as its used.  On some reference boards  
> we might put out more info because of the various configs these types  
> of boards can be setup in.  However if something has a static config  
> just describe that.  So in your example of two i2c buses with only one  
> connected, just describe the one that is used.

Hrm... I'd say this is not something which has a firm convention yet.

It's going to become more of an issue once we get a macros system for
dtc, so the "440EP" macro would have all the devices, even if some are
not connected on a given board.

I'm contemplating suggesting that we adopt the "status" property from
IEEE1275 to cover this.

David Gibson			| I'll have my music baroque, and my code
david AT	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!

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