[PATCH 14/17] dt-bindings/interrupt-controller: add description for Marvell SEI node

[Rob Herring]

On Sat, Apr 28, 2018 at 5:48 AM, Miquel Raynal
<miquel.raynal at bootlin.com> wrote:
> Hi Rob,
>
> On Fri, 27 Apr 2018 15:50:32 -0500, Rob Herring <robh at kernel.org> wrote:
>
>> On Sat, Apr 21, 2018 at 03:55:34PM +0200, Miquel Raynal wrote:
>> > Describe the SEI (System Error Interrupt) controller driver. The
>> > controller is part of the GIC. It aggregates two types of interrupts,
>> > wired and MSIs from respectively the AP and the CPs, into a single SPI
>> > interrupt.
>> >
>> > Suggested-by: Haim Boot <hayim at marvell.com>
>> > Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
>> > ---
>> >  .../bindings/interrupt-controller/marvell,sei.txt  | 54 ++++++++++++++++++++++
>> >  1 file changed, 54 insertions(+)
>> >  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,sei.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/marvell,sei.txt b/Documentation/devicetree/bindings/interrupt-controller/marvell,sei.txt
>> > new file mode 100644
>> > index 000000000000..a246d59552b1
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/interrupt-controller/marvell,sei.txt
>> > @@ -0,0 +1,54 @@
>> > +Marvell SEI (System Error Interrupt) Controller
>> > +-----------------------------------------------
>> > +
>> > +Marvell SEI (System Error Interrupt) controller is an interrupt aggregator.
>> > +It receives interrupts from several sources and aggregates them to a single
>> > +interrupt line (an SPI) on the primary interrupt controller.
>> > +
>> > +The IRQ chip can handle up to 64 SEIs, a set comes from the AP and is
>> > +wired while a second set comes from the CPs by the mean of MSIs. Each
>> > +'domain' is represented as a subnode.
>> > +
>> > +Required properties:
>> > +
>> > +- compatible: should be "marvell,armada-8k-sei".
>> > +- reg: SEI registers location and length.
>> > +- interrupts: identifies the parent IRQ that will be triggered.
>> > +- #address-cells: should be '1', represents the position of the first
>> > +                  IRQ of a given type in the SEI range.
>> > +- #size-cells: should be '1', represents the number of a given type of
>> > +               IRQs.
>> > +
>> > +Child node 'sei-wired-controller' required properties:
>> > +
>> > +- reg: the range of wired interrupts.
>> > +- #interrupt-cells: number of cells to define an SEI wired interrupt
>> > +                    coming from the AP, should be 1. The cell is the IRQ
>> > +                    number.
>> > +- interrupt-controller: identifies the node as an interrupt controller.
>> > +
>> > +Child node 'sei-msi-controller' required properties:
>> > +
>> > +- reg: the range of non-wired interrupts triggered by way of MSIs.
>> > +- msi-controller: identifies the node as an MSI controller.
>> > +
>> > +Example:
>> > +
>> > +        sei: sei at 3f0200 {
>> > +               compatible = "marvell,armada-8k-sei";
>> > +               reg = <0x3f0200 0x40>;
>> > +               interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>;
>> > +               #address-cells = <1>;
>> > +               #size-cells = <1>;
>> > +
>> > +               sei_wired_controller: sei-wired-controller at 0 {
>> > +                       reg = <0 21>;
>>
>> Using interrupt numbers in reg is strange.
>
> I thought the reg property was the one to choose here, I can of course
> change it, what would you suggest?
>
>>
>> > +                       #interrupt-cells = <1>;
>> > +                       interrupt-controller;
>> > +               };
>> > +
>> > +               sei_msi_controller: sei-msi-controller at 21 {
>> > +                       reg = <21 43>;
>> > +                       msi-controller;
>>
>> Can't the parent be both an interrupt-controller and msi-controller?
>
> We need to know which one aggregates interrupts, which one receives
> MSIs and most importantly which interrupt is what (within the 64
> that are handled by the SEI).

You mean that 0-20 are wired and 21-63 are msi? "marvell,msi-base =
<21>;" in the parent would be sufficient for that though you may want
something more flexible to have multiple ranges.

It looks like there may already be similar bindings. See
'msi-available-ranges" and "{al,arm},msi-base-spi".

Rob