Re: [PATCH] RFC: interrupt consistency check for OF GPIO IRQs

[Alexander Holler]

Am 12.09.2013 13:26, schrieb Alexander Holler:
> Am 12.09.2013 13:09, schrieb Alexander Holler:
> > Am 12.09.2013 12:28, schrieb Alexander Holler:
> > > Am 12.09.2013 12:11, schrieb Javier Martinez Canillas:
> > > > On 09/12/2013 10:55 AM, Alexander Holler wrote:
...
> > > > So, if I understood the code correctly the DT IRQ core doesn't expect
> > > > a device
> > > > node to have more than one "interrupt-parent" property.
> > > >
> > > > It *should* work though if you have multiple "interrupts" properties
> > > > defined and
> > > > all of them have the same "interrupt-parent":
> > > >
> > > >         interrupt-parent = <&gpio6>;
> > > >         interrupts = <1 IRQF_TRIGGER_HIGH>; /* GPIO6_1 */
> > > >         interrupts = <2 IRQF_TRIGGER_LOW>; /* GPIO6_2 */
> > > >
> > > > since of_irq_map_one() will be called for each "interrupts" and the
> > > > correct
> > > > "interrupt-parent" will get obtained by of_irq_find_parent().
> > >
> > > I assumed that answer. So to make such a scenario possible, something
> > > like this might be neccessary:
> > >
> > >           interrupts = <&gpio6 1 IRQF_TRIGGER_HIGH>; /* GPIO6_1 */
> > >           interrupts = <&gpio7 2 IRQF_TRIGGER_LOW>; /* GPIO7_2 */
> > >
> > > or, to be compatible
> > >
> > >           interrupts = <1 IRQF_TRIGGER_HIGH &gpio6>; /* GPIO6_1 */
> > >           interrupts = <1 IRQF_TRIGGER_LOW &gpio7>; /* GPIO7_1 */
> > >
> > > Another problem is the naming. In all the above cases, the driver would
> > > not know which IRQ he should use for what. Maybe the order defines it,
> > > but that wouldn't be very verbose. And I think just changing the name
> > > would make travelling the tree impossible, as only the driver itself
> > > would know the name and it's meaning.
> >
> > On a second look, travelling the tree is still possible if the solution
> > would be like above (without that interrupt-parent). So if a driver
> > requires two interrupts he could use
> >
> >        interrupt-foo = <1 IRQF_TRIGGER_HIGH &gpio6>; /* GPIO6_1 */
> >        interrupt-bar = <1 IRQF_TRIGGER_LOW &gpio7>; /* GPIO7_1 */
> >
> > And travelling the tree will still be possible because walking from the
> > interrupt-controllers (those gpio) downwards would end up at the
> > interrupt definitions, so the name of them isn't needed to find them in
> > the tree.
>
> I've just seen how they solved it for dma:
>
>              dmas = <&edma0 16
>                  &edma0 17>;
>              dma-names = "rx", "tx";
>
> so it would be like
>
>        interrupts = <1 IRQF_TRIGGER_HIGH &gpio6>; /* GPIO6_1 */
>        interrupts = <1 IRQF_TRIGGER_LOW &gpio7>; /* GPIO7_1 */
>        interrupt-names = "foo", "bar";
>
> Or this would be possible:
>
>        interrupt-parent = <&gpio6 &gpio7>;
>        interrupts = <1 IRQF_TRIGGER_HIGH>; /* GPIO6_1 */
>        interrupts = <1 IRQF_TRIGGER_LOW>; /* GPIO7_1 */
>        interrupt-names = "foo", "bar";

And looking at how gpios are defined, I think it should be like that:


          interrupts = <&gpio6 1 IRQF_TRIGGER_HIGH
                        &gpio7 2 IRQF_TRIGGER_LOW
          >;
          interrupt-names = "foo", "bar";

So without that interrupt-parent.

Regards,

Alexander

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