Re: [PATCH v3 1/2] dt-bindings/interrupt-controller: rzn1: Add RZ/N1 gpio irq mux binding

[Rob Herring <robh@kernel.org>]

On Mon, Nov 19, 2018 at 3:39 AM Phil Edworthy <phil.edworthy@renesas.com> wrote:
>
> Hi Rob,
>
> On 17 November 2018 14:33 Rob Herring wrote:
> > On Tue, Nov 13, 2018 at 01:09:09PM +0000, Phil Edworthy wrote:
> > > Add device binding documentation for the Renesas RZ/N1 GPIO interrupt
> > > multiplexer.
> > >
> > > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
> > > ---
> > > v3:
> > >  - Use 'interrupt-map' DT property correctly.
> > > v2:
> > >  - Use interrupt-map to allow the GPIO controller info to be specified
> > >    as part of the irq.
> > >  - Don't show status in binding examples.
> > >  - Don't show the soc/board split in binding doc.
> > > ---
> > >  .../interrupt-controller/renesas,rzn1-mux.txt | 73
> > > +++++++++++++++++++
> > >  1 file changed, 73 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/interrupt-controller/renesas,rzn1-mu
> > > x.txt
> >
> > A few nits, otherwise:
> >
> > Reviewed-by: Rob Herring <robh@kernel.org>
> Thanks for the review!
>
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/interrupt-controller/renesas,rzn1-
> > > mux.txt
> > > b/Documentation/devicetree/bindings/interrupt-controller/renesas,rzn1-
> > > mux.txt
> > > new file mode 100644
> > > index 000000000000..6515880e25cc
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/interrupt-controller/renesas,r
> > > +++ zn1-mux.txt
> > > @@ -0,0 +1,73 @@
> > > +* Renesas RZ/N1 GPIO Interrupt Multiplexer
> > > +
> > > +On Renesas RZ/N1 devices, there are several GPIO Controllers each
> > > +with a number of interrupt outputs. All of the interrupts from the
> > > +GPIO Controllers are passed to the GPIO Interrupt Multiplexer, which
> > > +selects a sub-set of the interrupts to pass onto the system interrupt
> > controller.
> > > +
> > > +A single node in the device tree is used to describe the GPIO IRQ Muxer.
> > > +
> > > +Required properties:
> > > +- compatible: SoC-specific compatible string "renesas,<soc-specific>-
> > gpioirqmux"
> > > +  followed by "renesas,rzn1-gpioirqmux" as fallback. The SoC-specific
> > > +compatible
> > > +  strings must be one of:
> > > +   "renesas,r9a06g032-gpioirqmux" for RZ/N1D
> > > +   "renesas,r9a06g033-gpioirqmux" for RZ/N1S
> > > +- reg: Base address and size of GPIO IRQ Muxer registers.
> > > +- interrupts: List of output interrupts.
> > > +- #interrupt-cells: Numder of cells in the input interrupt specifier, must be
> > 1.
> > > +- #address-cells: Must be 0.
> > > +- interrupt-map-mask: must be 127.
> > > +- interrupt-map: Standard property detailing the maps between input
> > > +irqs and the
> > > +  corresponding output irq. This consist of a list of:
> > > +   <input-irq-spec phandle-to-interrupt-controller output-irq-spec>
> > > +  The input-irq-spec is from 0 to 95, corresponding to the outputs of
> > > +the GPIO
> > > +  Controllers.
> > > +
> > > +Example:
> > > +
> > > +   The following is an example for the RZ/N1D SoC.
> > > +
> > > +   gpioirqmux: gpioirqmux@51000480 {
> >
> > interrupt-controller@...
> Sure
>
> > > +           compatible = "renesas,r9a06g032-gpioirqmux",
> > > +                           "renesas,rzn1-gpioirqmux";
> > > +           reg = <0x51000480 0x20>;
> > > +           interrupts =
> > > +                   <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>,
> > > +                   <GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>;
> >
> > This is a bit redundant as the same information is in interrupt-map, but I
> > guess you need it to get the irq resources.
> That's right.
>
> > > +
> > > +           #interrupt-cells = <1>;
> > > +           #address-cells = <0>;
> > > +           interrupt-map-mask = <127>;
> >
> > Use hex for masks.
> Ok.
>
> > > +           interrupt-map =
> > > +                   /* gpio2a 24, pin 146: ETH Port 1 IRQ */
> > > +                   <88 &gic GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>,
> > > +                   /* gpio2a 26, pin 148: TouchSCRN_IRQ */
> > > +                   <90 &gic GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>;
> > > +   };
> > > +
> > > +   gpio2: gpio@5000d000 {
> > > +           compatible = "snps,dw-apb-gpio";
> > > +           reg = <0x5000d000 0x80>;
> > > +           #address-cells = <1>;
> > > +           #size-cells = <0>;
> > > +           clock-names = "bus";
> > > +           clocks = <&sysctrl R9A06G032_HCLK_GPIO2>;
> > > +
> > > +           gpio2a: gpio-controller@0 {
> >
> > gpio@0
> Are you sure about this?

Yes, 'gpio' is what the DT spec says. It is the oddball though and I
always have to think about it.

> The bindings in Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
> show an example where the sub-nodes for gpio banks are gpio-controller@.
> This is also in Documentation/devicetree/bindings/gpio/gpio.txt.

Indeed. Those should be fixed. I would be easily persuaded to just
change the spec, but 'gpio@' is much more widely used:

$ git grep gpio@ -- arch/ | wc
   1110    4378   67766
$ git grep gpio-controller@ -- arch/ | wc
     60     232    4270

Rob