Subject: Re: [PATCH 15/16] Add device tree for Ebony

From: Segher Boessenkool <[email-masked]>
Date: Wed, 14 Feb 2007 18:48:02 +0100

>>> +			clock-frequency = <5F5E100>; /* 100MHz FIXME: poke in zImage */
>>> +			timebase-frequency = <5F5E100>; /* 100MHz FIXME: wrong, poke in
>>> zImage */
>>
>> Can't you use decimal for these?
>
> dtc doesn't support decimal cells at present.  Suggest a good syntax
> for doing it, and I'll add the feature.

d# 100000000    like is used in "real" OF?

>>> +	UIC0: interrupt-controller { /* UIC0 */
>>
>>> +		#address-cells = <0>;
>>> +		#size-cells = <0>;
>>
>> #address-cells = 0 never makes sense.
>
> Why not?  Children of this node have and need no reg property, and no
> meaningful address.  Sounds like #address-cells = 0 to me.

There cannot *exist* any children of the node.  Unless
your hardware is really weird.  I guess it is :-)

In such a case, you just don't put a "reg" property in
the kid nodes.

>>> +	plb {
>>> +		device_type = "soc";
>>> +		compatible = "ibm,plb-440gp", "ibm,plb4";
>>> +		ranges;
>>
>> You need a #address-cells, #size-cells here.
>
> Why?  The values inherited from the root node are perfectly ok here.

Values aren't inherited.  Missing #address-cells, #size-cells
properties mean 2 and 1 respectively.  And it's good practice
to always fill them in explicitly.

Segher