[PATCH 1/2] powerpc: document the MPIC device tree binding
scottwood at freescale.com
Wed Jan 19 07:31:31 EST 2011
On Mon, 17 Jan 2011 18:52:24 -0600
Meador Inge <meador_inge at mentor.com> wrote:
> +** Required properties:
> + NOTE: Many of these descriptions were paraphrased from  to aid
> + readability.
> + - name : Specifies the name of the MPIC.
"name" isn't really a property with flat trees. The appropriate
node name, according to the Generic Names recommendation and ePAPR, is
> + - device_type : Specifies the device type of this MPIC. The value
> of this
> + property shall be "open-pic".
Can we drop device_type, and fix the kernel to look for compatible
> + - compatible : Specifies the compatibility list for the MPIC. The
> + value shall include "chrp,open-pic".
ePAPR wants just "open-pic". And while chrp,open-pic is common in
existing trees, only one platform currently checks for it.
I'd make in "open-pic" in the binding, and have the kernel accept
> +** Optional properties:
> + - no-reset : The presence of this property indicates that the MPIC
> + should not be reset during runtime initialization.
> + - protected-sources : Specifies a list of interrupt sources that are
> + available for use and whose corresponding vectors
> + should not be initialized. A typical use case for
> + this property is in AMP systems where multiple
> + independent operating systems need to share
> the MPIC
> + without clobbering each other.
Can we define no-reset as meaning that all vectors are in a sane state
(either directed at other cores, or masked)?
If we do that, maybe we can get rid of protected-sources.
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