Messages in this thread | | | Date | Fri, 7 Mar 2014 15:08:56 -0800 | From | Stephen Boyd <> | Subject | Re: [PATCH v5 2/4] devicetree: bindings: Document Krait CPU/L1 EDAC |
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On 02/26, Lorenzo Pieralisi wrote: > On Tue, Feb 25, 2014 at 08:48:38PM +0000, Kumar Gala wrote: > > > > On Feb 25, 2014, at 5:16 AM, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote: > > > > > > As I mentioned, I do not like the idea of adding compatible properties > > > just to force the kernel to create platform devices out of device tree > > > nodes. On top of that I would avoid adding a compatible property > > > to the cpus node (after all properties like enable-method are common for all > > > cpus but still duplicated), my only concern being backward compatibility > > > here (ie if we do that for interrupts, we should do that also for other > > > common cpu nodes properties, otherwise we have different rules for > > > different properties). > > > > > > I think you can then add interrupts to cpu nodes ("qcom,krait" specific), > > > and as you mentioned create a platform device for that. > > > > > > Thanks, > > > Lorenzo > > > > So I agree with the statement about adding compatibles just to create platform devices is wrong. However its seems perfectly reasonable for a cpu node to have a compatible property. I don't see why a CPU is any different from any other device described in a DT. > > I was referring to the /cpus node, not to individual cpu nodes, where > the compatible property is already present now. >
Ok I think I'll go ahead with moving the interrupts into each cpu node, i.e.:
cpus { #address-cells = <1>; #size-cells = <0>;
cpu@0 { compatible = "qcom,krait"; device_type = "cpu"; reg = <0>; interrupts = <1 14 0x304>; next-level-cache = <&L2>; };
cpu@1 { compatible = "qcom,krait"; device_type = "cpu"; reg = <1>; interrupts = <1 14 0x304>; next-level-cache = <&L2>; };
L2: l2-cache { compatible = "cache"; interrupts = <0 2 0x4>; }; };
Or should we be expressing the L1 cache as well? Something like:
cpus { #address-cells = <1>; #size-cells = <0>;
cpu@0 { compatible = "qcom,krait"; device_type = "cpu"; reg = <0>; next-level-cache = <&L1_0>;
L1_0: l1-cache { compatible = "arm,arch-cache"; interrupts = <1 14 0x304>; next-level-cache = <&L2>; } };
cpu@1 { compatible = "qcom,krait"; device_type = "cpu"; reg = <1>; next-level-cache = <&L1_1>;
L1_1: l1-cache { compatible = "arm,arch-cache"; interrupts = <1 14 0x304>; next-level-cache = <&L2>; } };
L2: l2-cache { compatible = "arm,arch-cache"; interrupts = <0 2 0x4>; }; };
(I'm also wondering if the 3rd cell of the interrupt binding should only indicate the CPU that the interrupt property is inside?)
Finally we can have the edac driver look for a "qcom,krait" compatible node in cpus that it can create a platform device for, i.e..
static int __init krait_edac_driver_init(void) { struct device_node *np;
np = of_get_cpu_node(0, NULL); if (!np) return 0;
if (!krait_edacp && of_device_is_compatible(np, "qcom,krait")) krait_edacp = of_platform_device_create(np, "krait_edac", NULL); of_node_put(np);
return platform_driver_register(&krait_edac_driver); } module_init(krait_edac_driver_init);
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