On Thu, Feb 13, 2014 at 6:59 AM, Marc Zyngier [off-list ref] wrote:

Hi Arnab,

On 07/02/14 05:41, Arnab Basu wrote:

quoted

Hi Marc

Marc Zyngier <marc.zyngier <at> arm.com> writes:

quoted

+
+AArch64 SMP cores are often associated with a GICv3, providing private
+peripheral interrupts (PPI), shared peripheral interrupts (SPI),
+software generated interrupts (SGI), and locality-specific peripheral
+Interrupts (LPI).
+
+Main node required properties:
+
+- compatible : should at least contain  "arm,gic-v3".
+- interrupt-controller : Identifies the node as an interrupt controller
+- #interrupt-cells : Specifies the number of cells needed to encode an
+  interrupt source. Must be a single cell with a value of at least 3.
+
+  The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
+  interrupts. Other values are reserved for future use.

These values are defined in
"include/dt-bindings/interrupt-controller/arm-gic.h" maybe we should start
mentioning that here and encourage future device treese to use those defines
to improve readability.

It may improve readability, but it makes the definition rely on
something else. Definition and usage are two different things, and I
want the definition to be completely self-contained and non ambiguous.

In DTS files, people can use whatever macro they decide, and it is their
problem. They will even have out of tree DTS files, for which the
include file is not available.

Agreed.

Rob