[PATCH 1/2] Documentation: devicetree: arm: cpus/cpu nodes bindings updates

[Lorenzo Pieralisi]

On Fri, Sep 13, 2013 at 09:51:56PM +0100, Rob Herring wrote:
> On 09/13/2013 11:57 AM, Lorenzo Pieralisi wrote:
> > Hi Rob, all,
> > 
> > On Thu, Aug 15, 2013 at 04:22:38PM +0100, Lorenzo Pieralisi wrote:
> >> [adding Andrew, Gregory and Thomas to check the Marvell compatible names]
> >>
> >> On Thu, Aug 15, 2013 at 03:32:05PM +0100, Rob Herring wrote:
> >>> On 08/15/2013 04:42 AM, Lorenzo Pieralisi wrote:
> >>>> In order to extend the current cpu nodes bindings to newer CPUs
> >>>> inclusive of AArch64 and to update support for older ARM CPUs this
> >>>> patch updates device tree documentation for the cpu nodes bindings.
> >>>>
> >>>> Main changes:
> >>>>     - adds 64-bit bindings
> >>>>     - define usage of #address-cells
> >>>>     - defines behaviour on pre and post v7 uniprocessor systems
> >>>>     - adds ARM 11MPcore specific reg property definition
> >>>>
> >>>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> >>>> ---
> >>>>  Documentation/devicetree/bindings/arm/cpus.txt | 424 ++++++++++++++++++++++---
> >>>>  1 file changed, 377 insertions(+), 47 deletions(-)
> >>>>
> >>>
> >>> The binding looks mostly fine to me.
> > 
> > These bindings have still not received an ACK, and need review by
> > Marvell guys in copy for the new compatible strings below.
> 
> If you can't get comment, then leave them out if they are not used
> already. If they are used, then tough shit when they want to change.
> 
> > 
> > Most importantly, we need to make a decision on the pre v7 uniprocessor
> > systems, where MPIDR/CPUID are non-existent and the reg property is a
> > pure SW enumeration. Current bindings (ie this patch) define
> > 
> > #address-cells = <0>;
> > 
> > for those processors (and there are a number of dts in the kernel with that
> > set-up); Grant and Benjamin had a strong feeling against this choice, I
> > have to make a decision on how to proceed, please let me know.
> 
> I agree that we should define #address-cells to 1 and reg will be simply
> 0,1,2,etc. in this case.

Ok, so this means that when these bindings are finally acked and queued
for merging, there will be a slew of dts in the kernel that will need
patching (again) and this is likely to ruffle feathers. Honestly I would
leave this task to platform maintainers, if we all agree.

> This change and fixing the example as I pointed out are what I was
> waiting to see.

Perfect, given that I got feedback from Andrew, I will be posting a
final version very soon.

Lorenzo