[PATCH v2 2/6] pintrl: meson: document GPIO IRQ DT binding

[Jerome Brunet]

On Wed, 2017-05-17 at 23:02 +0200, Heiner Kallweit wrote:
> Am 17.05.2017 um 01:28 schrieb Jerome Brunet:
> > On Fri, 2017-05-12 at 21:13 +0200, Heiner Kallweit wrote:
> > > Document the DT binding for GPIO IRQ support on Amlogic Meson SoC's.
> > > 
> > > This documentation is intentionally not placed under
> > > interrupt-controllers as GPIO IRQ support on these SoC's acts more
> > > like an interrupt multiplexer.
> > > 
> > > Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
> > > ---
> > > v2:
> > > - remove syscon
> > > ---
> > >  arch/arm64/boot/dts/amlogic/meson-gx.dtsi | 13 +++++++++++++
> > >  1 file changed, 13 insertions(+)
> > > 
> > > diff --git a/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> > > b/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> > > index 436b8750..44422b85 100644
> > > --- a/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> > > +++ b/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> > > @@ -312,6 +312,19 @@
> > >  				status = "disabled";
> > >  			};
> > >  
> > > +			gpio_irq at 9880 {
> > > +				compatible = "amlogic,meson-gpio-
> > > interrupt";
> > > +				reg = <0x0 0x09880 0x0 0x10>;
> > > +				interrupts = <GIC_SPI 64 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 65 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 66 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 67 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 68 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 69 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 70 IRQ_TYPE_NONE>,
> > > +					     <GIC_SPI 71 IRQ_TYPE_NONE>;
> > > +			};
> > > +
> > 
> > Already tried the same thing:
> > https://marc.info/?l=devicetree&m=147758174404359&w=2
> > 
> > Irq maintainers reminded me that this is not correct as the device is not
> > able
> > to generate these particular irqs (it is merely routing the signal) and the
> > flags are meaning less here
> > 
> 
> In one review comment to your patch series Rob mentioned to be fine with using
> the standard interrupts property.
> However other involved people might have had a different opinion, I didn't
> read
> all review comments.
> 
> I think the standard interrupts property is the best way.
> We need mapped virq's to be used with the irq chaining. And for mapping an
> interrupt we need not only the hwirq but also the IRQ domain. The interrupts
> property and the related OF IRQ API calls like irq_of_parse_and_map provide
> exactly what we need.
> 
> If somebody has serious objections to using the interrupts property then we
> basically had to duplicate it and just give it a different name.

You got the objections in my previous comment.
* This driver does *not* generate these irq, it just route them
* IRQ_TYPE_NONE in meaningless here

This comments initially came from Mark and Marc, on the first RFC I sent lastyear. 

> And such code duplication to me seems to be worse than using the interrupts
> property slightly different than in the theory.
> 
> > 
> > >  			watchdog at 98d0 {
> > >  				compatible = "amlogic,meson-gx-wdt",
> > > "amlogic,meson-gxbb-wdt";
> > >  				reg = <0x0 0x098d0 0x0 0x10>;
> 
>