Re: [PATCH 3/6] irqchip: irq-st: Add documentation for STi based syscfg IRQs

From: Lee Jones
Date: Fri Sep 26 2014 - 05:52:21 EST


On Mon, 18 Aug 2014, Jason Cooper wrote:

> Hey Lee,
>
> Rob, Grant, question for you below:
>
> On Tue, Jul 29, 2014 at 03:05:41PM +0100, Lee Jones wrote:
> > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> > ---
> > .../interrupt-controller/st,sti-irq-syscfg.txt | 35 ++++++++++++++++++++++
> > 1 file changed, 35 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
> >
> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt b/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
> > new file mode 100644
> > index 0000000..ced6014
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
> > @@ -0,0 +1,35 @@
> > +STMicroelectronics STi System Configuration Controlled IRQs
> > +-----------------------------------------------------------
> > +
> > +On STi based systems; External, CTI (Core Sight), PMU (Performance Management),
> > +and PL310 L2 Cache IRQs are controlled using System Configuration registers.
> > +This driver is used to unmask them prior to use.
>
> We don't usually refer to the driver in binding docs as they are
> supposed to be OS-agnostic.

I beg to differ:

$ git grep -i driver -- Documentation/devicetree/ | wc -l
355

I can understand if I was referencing Linux driver implementation
specifics, but any of the OS's drivers would also be un/masking IRQs
in order to provide this functionality.


> > +Required properties:
> > +- compatible : Should be set to one of:
> > + "st,stih415-irq-syscfg"
> > + "st,stih416-irq-syscfg"
> > + "st,stih407-irq-syscfg"
> > + "st,stid127-irq-syscfg"
> > +- st,syscfg : Phandle to Cortex-A9 IRQ system config registers
> > +- st,irq-device : Array of IRQs to enable - should be 2 in length
> > +- st,fiq-device : Array of FIQs to enable - should be 2 in length
> > +
> > +Optional properties:
> > +- st,invert-ext : External IRQs can be inverted at will. This property inverts
> > + these IRQs using bitwise logic. A number of defines have been
> > + provided for convenience:
> > + ST_IRQ_SYSCFG_EXT_1_INV
> > + ST_IRQ_SYSCFG_EXT_2_INV
> > + ST_IRQ_SYSCFG_EXT_3_INV
> > +Example:
>
> Rob, Grant, should we be mingling implementation details (macros from
> include files) with the binding documentation? It just _seems_ wrong
> too me. But if we agree that the binding docs, the dts files, and their
> includes are always kept together, I also don't see the harm...

IMHO, we should be able to document anything here which appears in the
DTS(I) files.

> > +irq-syscfg {
> > + compatible = "st,stih416-irq-syscfg";
> > + st,syscfg = <&syscfg_cpu>;
> > + st,irq-device = <ST_IRQ_SYSCFG_PMU_0>,
> > + <ST_IRQ_SYSCFG_PMU_1>;
> > + st,fiq-device = <ST_IRQ_SYSCFG_DISABLED>,
> > + <ST_IRQ_SYSCFG_DISABLED>;
> > + st,invert-ext = <(ST_IRQ_SYSCFG_EXT_1_INV | ST_IRQ_SYSCFG_EXT_3_INV)>;
> > +};

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/