Subject: Re: [PATCH] powerpc: document new interrupt-array property

From: Segher Boessenkool <[email-masked]>
Date: Fri, 23 Feb 2007 22:30:54 +0100

>> I'd rather write it like
>>
>>>       interrupts        = < a 4   b 4   0 4   1 4   2 4 >
>>>       interrupt-parents = <&UIC0 &UIC0 &UIC1 &UIC1 &UIC1>
>>
>
> Segher, with your proposal here of an interrupt-parents property
> is this really keeping with the normal OF way of representing
> property values?
>
> Examples exists where one property tells you how to interpret
> or decode another (e.g. #address-cells), but your proposal we
> have two distinct properties each with values that together
> provide the complete 'value' (interrupt parent + interrupt
> specifier).  Is there any precedent for this approach?

"interrupt-parent" normally is a separate property already.
"My" way, you keep the original definition for "interrupts"
and the bleeding obvious definition for "interrupt-parents".

An example where two arrays with corresponding entries is
already used is "alternate-reg" in the PCI binding.  There
are literally hundreds of examples of non-array properties
that only make sense together, of course.

Both "alternate-reg" and "interrupt-parents" can be seen as
an optional extension to their corresponding array properties
("reg" and "interrupts" respectively) so it all makes perfect
sense (to me, at least ;-) ).

Segher