On Thu, Jan 16, 2014 at 06:05:05PM +0000, Stephen Boyd wrote: > On 01/16, Lorenzo Pieralisi wrote: > > On Thu, Jan 16, 2014 at 01:38:40AM +0000, Stephen Boyd wrote: > > > On 01/15, Stephen Boyd wrote: > > > > > > > > Ah sorry, I forgot to put the compatible property here like in > > > > the dts change. I'll do that in the next revision. Yes we need a > > > > compatible property here to match the platform driver. > > > > > > > > > > This is the replacement patch > > > > > > -----8<------ > > > From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > > > Subject: [PATCH v9] devicetree: bindings: Document Krait CPU/L1 EDAC > > > > > > The Krait CPU/L1 error reporting device is made up a per-CPU > > > interrupt. While we're here, document the next-level-cache > > > property that's used by the Krait EDAC driver. > > > > > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > > > Cc: Mark Rutland <mark.rutland@xxxxxxx> > > > Cc: Kumar Gala <galak@xxxxxxxxxxxxxx> > > > Cc: <devicetree@xxxxxxxxxxxxxxx> > > > Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > > > --- > > > Documentation/devicetree/bindings/arm/cpus.txt | 58 ++++++++++++++++++++++++++ > > > 1 file changed, 58 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt > > > index 91304353eea4..03a529e791c4 100644 > > > --- a/Documentation/devicetree/bindings/arm/cpus.txt > > > +++ b/Documentation/devicetree/bindings/arm/cpus.txt > > > @@ -62,6 +62,20 @@ nodes to be present and contain the properties described below. > > > Value type: <u32> > > > Definition: must be set to 0 > > > > > > + - compatible > > > + Usage: optional > > > + Value type: <string> > > > + Definition: should be one of the compatible strings listed > > > + in the cpu node compatible property. This property > > > + shall only be present if all the cpu nodes have the > > > + same compatible property. > > > > Do we really want to do that ? I am not sure. A cpus node is supposed to > > be a container node, we should not define this binding just because we > > know the kernel creates a platform device for it then. > > This is just copying more of the ePAPR spec into this document. > It just so happens that having a compatible field here allows a > platform device to be created. I don't see why that's a problem. I do not see why you cannot define a node like pmu or arch-timer and stick a compatible property in there. cpus node does not represent a device, and must not be created as a platform device, that's my opinion. What would you do for big.LITTLE systems ? We are going to create two cpus node because we need two platform devices ? I really think there must be a better way to implement this, but I will let DT maintainers make a decision. > > interrupts is a cpu node property and I think it should be kept as such. > > > > I know it will be duplicated and I know you can't rely on a platform > > device for probing (since if I am not mistaken, removing a compatible > > string from cpus prevents its platform device creation), but that's an issue > > related to how the kernel works, you should not define DT bindings to solve > > that IMHO. > > The interrupts property is also common for all cpus so it seems > fine to collapse the value down into a PPI specifier indicating > that all CPUs get the interrupt, similar to how we compress the > information about the compatible string. I think it is nicer to create a device node (as I said, like a pmu or an arch-timer) and define interrupts there along with a proper compatible property. This would serve the same purpose without adding properties in the cpus node. cpu-edac { compatible = "qcom,cpu-edac"; interrupts = <...>; }; Thanks, Lorenzo -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html