[RFC] mpc5200 device tree bindings refinement

Mark A. Greer mgreer at mvista.com
Sat Feb 10 04:31:49 EST 2007


On Fri, Feb 09, 2007 at 12:30:09AM -0700, Grant Likely wrote:

Hi Grant,

> Much needed refinement of mpc5200 device tree binding specifications.
> 
> Short list:

<snip>

> - Specify reqiured 'cell-index' property to identify between multiple SOC
>   devices of the same type.  (Useful for arbitrating shared register access)

<snip>

> +Important child node properties
> +name		type		description
> +----		----		-----------
> +cell-index	int		When multiple devices are present, is the
> +				index of the device in the hardware (ie. There
> +				are 6 PSC on the 5200 numbered PSC1 to PSC6)
> +				    PSC1 has 'cell-index = <0>'
> +				    PSC4 has 'cell-index = <3>'
> +

Dale Farnsworth and I have the exact same problem with the Marvell
bridges (e.g., 2 MPSC ctlrs use different bits in the same reg).
Yesterday we talked about it for a while and came up with essentially
the same solution as you.  The only difference is that we called the
property "register-set".  I think that is a better name because a)
"cell-index" sounds like an index into a DT cell which it isn't, and b)
its more descriptive (IMHO) because its really saying what set of regs
or bits in a reg are for that ctlr.

Comments?

Mark



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