Re: [RFC PATCH v2 12/13] ARM: mach-vt8500: cpus/cpu nodes dts updates

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Tue, Apr 23, 2013 at 03:43:48AM +0100, Tony Prisk wrote:
> On 23/04/13 03:27, Lorenzo Pieralisi wrote:
> > This patch updates the in-kernel dts files according to the latest cpus
> > and cpu bindings updates for ARM.
> >
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > ---
> >   arch/arm/boot/dts/wm8505.dtsi | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/boot/dts/wm8505.dtsi b/arch/arm/boot/dts/wm8505.dtsi
> > index e74a1c0..a470808 100644
> > --- a/arch/arm/boot/dts/wm8505.dtsi
> > +++ b/arch/arm/boot/dts/wm8505.dtsi
> > @@ -13,7 +13,7 @@
> >   
> >   	cpus {
> >   		cpu@0 {
> > -			compatible = "arm,arm926ejs";
> > +			compatible = "arm,arm926";
> >   		};
> >   	};
> >   
> The more I look at this, the more wrong it is :/
> 
>  From the new binding documentation,
> 
> +	A cpus node must define the following properties:
> +
> +	- #address-cells
> +		Usage: required
> +		Value type: <u32>
> +		Definition: must be set to 1 for 32-bit systems and 2 for
> +			    64-bit systems
> +	- #size-cells
> +		Usage: required
> +		Value type: <u32>
> +		Definition: must be set to 0
> 
> ...
> 
> +- cpu node
> +
> +	Description: Describes a CPU in an ARM based system
> +
> +	PROPERTIES
> +
> +	- device_type
> +		Usage: required
> +		Value type: <string>
> +		Definition: must be "cpu"
> 

This property is required since DT was invented, again, I should not be
in charge of adding it.

> Three required properties that aren't present in the patch.
> 
> cpus {
>      #size-cells = <0>;
>      #address-cells = <1>;
> 
>      cpu {
>          device_type = "cpu"
>          compatible = "arm,arm926";
>      };
> };

I am of two minds about this. That processor does not have an MPIDR
equivalent so in theory #address-cells and #size-cells could be omitted
because the reg property is meaningless. I do not know to be honest the
best way to handle this.

Thoughts ?

Thanks for the review,
Lorenzo