[PATCH] ARM: gic: Document Power and Clock Domain optional properties

From: Geert Uytterhoeven
Date: Mon Apr 27 2015 - 11:00:34 EST


On some SoCs, the GIC may be part of a PM Domain (hardware Power and/or
Clock Domain). Document the related optional DT properties.

Note: As the current GIC driver doesn't support Runtime PM yet, PM
Domain constraints must be handled elsewhere in e.g. platform code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
To preserve DT stability, we would like to add these properties to the
affected shmobile dtsi files.

On Thu, Mar 26, 2015 at 11:39 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote:
> On 25/03/15 21:19, Geert Uytterhoeven wrote:
>> I would like to add the clock and GIC dependency on the clock in the DTS now,
>> for reasons of DTS stability. But that means I need a temporary workaround
>> to avoid the clock from being disabled, until the GIC driver handles this.
>>
>> I don't expect a fix for the GIC code to just show up magically. I just wanted
>> you to be aware of the problem. GIC is not the only problematic module here,
>> there are others, cfr. the last slide of [2].
>
> As long as there is an agreement from the DT people on the presence of
> that extra property in the GIC node, I'm happy with that. I'd like it to
> be documented though.

Full thread at
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-March/331876.html

Documentation/devicetree/bindings/arm/gic.txt | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
index 2da059a4790cb3c6..b21113b35f085f27 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -58,6 +58,14 @@ Optional
regions, used when the GIC doesn't have banked registers. The offset is
cpu-offset * cpu-nr.

+- power-domains : A phandle and PM domain specifier as defined by bindings of
+ the power controller specified by phandle, used when the GIC
+ is part of a Power or Clock Domain.
+
+- clocks : A phandle and clock specifier as defined by bindings of
+ the clock controller specified by phandle, used when the GIC
+ is part of a Clock Domain.
+
Example:

intc: interrupt-controller@fff11000 {
--
1.9.1

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