Re: [PATCH v2 12/16] dt-bindings/interrupt-controller: update Marvell ICU bindings

Miquel Raynal
2018-06-08T14:01:16Z

Hi Rob,

Thanks for reviewing.

On Tue, 5 Jun 2018 14:29:02 -0600, Rob Herring <robh@kernel.org> wrote:

> On Tue, May 22, 2018 at 11:40:38AM +0200, Miquel Raynal wrote:
> > Change the documentation to reflect the new bindings used for Marvell
> > ICU. This involves describing each interrupt group as a subnode of the
> > ICU node. Each of them having their own compatible.
>
> Need to explain why you need to do this and why breaking backwards
> compatibility is okay.

As explained by Thomas, backward compatibility is not broken as old
bindings are still documented and supported.

I will update the commit message to reflect that point.

>
> >
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> > .../bindings/interrupt-controller/marvell,icu.txt | 81 ++++++++++++++++++----
> > 1 file changed, 69 insertions(+), 12 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt b/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> > index 649b7ec9d9b1..6f7e4355b3d8 100644
> > --- a/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> > +++ b/Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> > @@ -5,6 +5,8 @@ The Marvell ICU (Interrupt Consolidation Unit) controller is
> > responsible for collecting all wired-interrupt sources in the CP and
> > communicating them to the GIC in the AP, the unit translates interrupt
> > requests on input wires to MSG memory mapped transactions to the GIC.
> > +These messages will access a different GIC memory area depending on
> > +their type (NSR, SR, SEI, REI, etc).
> >
> > Required properties:
> >
> > @@ -12,20 +14,19 @@ Required properties:
> >
> > - reg: Should contain ICU registers location and length.
> >
> > +Subnodes: Each group of interrupt is declared as a subnode of the ICU,
> > +with their own compatible.
> > +
> > +Required properties for the icu_nsr/icu_sei subnodes:
> > +
> > +- compatible: Should be "marvell,cp110-icu-nsr" or "marvell,cp110-icu-sei".
> > +
> > - #interrupt-cells: Specifies the number of cells needed to encode an
> > - interrupt source. The value shall be 3.
> > + interrupt source. The value shall be 2.
> >
> > - The 1st cell is the group type of the ICU interrupt. Possible group
> > - types are:
> > + The 1st cell is the index of the interrupt in the ICU unit.
> >
> > - ICU_GRP_NSR (0x0) : Shared peripheral interrupt, non-secure
> > - ICU_GRP_SR (0x1) : Shared peripheral interrupt, secure
> > - ICU_GRP_SEI (0x4) : System error interrupt
> > - ICU_GRP_REI (0x5) : RAM error interrupt
>
> What happens to SR and REI interrupts?

They were unused since the beginning.

These values are still detailed below (in the legacy section).

[...]

>
> > -
> > - The 2nd cell is the index of the interrupt in the ICU unit.
> > -
> > - The 3rd cell is the type of the interrupt. See arm,gic.txt for
> > + The 2nd cell is the type of the interrupt. See arm,gic.txt for
> > details.
> >
> > - interrupt-controller: Identifies the node as an interrupt
> > @@ -35,17 +36,73 @@ Required properties:
> > that allows to trigger interrupts using MSG memory mapped
> > transactions.
> >
> > +Note: each 'interrupts' property referring to any 'icu_xxx' node shall
> > + have a different number within [0:206].
> > +
> > Example:
> >
> > icu: interrupt-controller@1e0000 {
> > compatible = "marvell,cp110-icu";
> > reg = <0x1e0000 0x440>;
> > +
> > + CP110_LABEL(icu_nsr): icu-nsr {
>
> 'interrupt-controller' is the proper node name. Is there no register
> range associated sub nodes?

I will update the name.

A few are used only for NSR, a few only for SEI and others are used for
both. But ok, I will add register ranges.

>
> > + compatible = "marvell,cp110-icu-nsr";
> > + #interrupt-cells = <2>;
> > + interrupt-controller;
> > + msi-parent = <&gicp>;
> > + };
> > +
> > + CP110_LABEL(icu_sei): icu-sei {
> > + compatible = "marvell,cp110-icu-sei";
> > + #interrupt-cells = <2>;
> > + interrupt-controller;
> > + msi-parent = <&sei>;
> > + };
>
> Mixture of tabs and spaces.

Oops.

>
> > +};
> > +

Thanks,
Miquèl