RFC: proposal to extend the open-pic interrupt specifier definition

[David Gibson]

On Tue, Jan 05, 2010 at 04:28:12PM -0700, Yoder Stuart-B08248 wrote:
> 
> The current open-pic binding defines that interrupt specifiers
> have 2 cells-- an interrupt number and level/sense encoding.
> 
> With chips like the P4080 this is no longer sufficient to
> represent the various types of interrupt sources handled by
> the interrupt controller.  A linear list of interrupt numbers
> doesn't handle all interrupt types-- there are at least 4 different
> kinds of interrupts on the P4080.
> 
> We have a proposal to extend the open-pic binding in
> a backwards compatible way to encode additional information
> in the level/sense field.
> 
> The current definition of level/sense is:
>   0 = low to high edge sensitive type enabled
>   1 = active low level sensitive type enabled
>   2 = active high level sensitive type enabled
>   3 = high to low edge sensitive type enabled
> 
> Those 2 bits would retain their current meaning, but the
> full encoding would be extended as follows:
> 
>      bits      meaning
>      ----------------------------------------------
>      0-7       interrupt sub-type
>      8-15      interrupt type
>      16-23     implementation dependent
>      24-29     reserved
>      30-31     level/sense encoding

Um.. what do "type" and "sub-type" mean in this context?

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson