[PATCH] Documentation: Add device tree binding file for MOXA ART SoCs interrupt controller

[Jonas Jensen]

Hi Mark,

On 2 August 2013 11:35, Mark Rutland <mark.rutland at arm.com> wrote:
>>     The MOXA ART irqchip driver was added without accompanying devicetree document.
>>     ( in next-20130716   drivers/irqchip/irq-moxart.c )
>
> Aaargh. That should not have happened >:(

Sorry about this, my plan was to submit all documents along with
moxart platform support. At the time I did not know it is more normal
to push the binding along with the driver.

>> +- interrupt-mask: Specifies if the interrupt is edge or level-triggered
>> +  each bit represent an interrupt 0-31 where 1 signify edge
>
> For the GIC, this gets descrbied in the interrupt sepcifier rather than
> on the interrupt controller's root node. Is there a reason to do this
> differently here?

The reason is, IRQ types must be written to the controller as two u32
registers (IRQ_MODE_REG and IRQ_LEVEL_REG). I could not find an easier
way (that uses generic things) to do it.

It's true that "interrupt-mask" is redundant, DT "interrupts" hold the
same information. I just never found nice way to collect it from DT.

See registers written on line 111:
http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/drivers/irqchip/irq-moxart.c#n111


Best regards,
Jonas