Messages in this thread | | | From | Laurent Pinchart <> | Subject | Re: How to create IRQ mappings in a GPIO driver that doesn't control its IRQ domain ? | Date | Wed, 31 Jul 2013 13:14:47 +0200 |
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Hi Grant,
On Saturday 27 July 2013 23:00:21 Grant Likely wrote: > On Thu, 25 Jul 2013 15:22:29 +0200, Laurent Pinchart wrote: > > On Thursday 25 July 2013 14:15:56 Mark Brown wrote: > > > On Thu, Jul 25, 2013 at 11:45:33AM +0200, Laurent Pinchart wrote: > > > > The two devices are independent, so there's no real parent/child > > > > relationship. However, as Grant proposed, I could list all the > > > > interrupts associated with GPIOs in the GPIO controller DT node. I > > > > would then just call irq_of_parse_and_map() in the .to_irq() handler > > > > to magically translate the GPIO number to a mapped IRQ number. > > > > > > > > The number of interrupts can be pretty high (up to 58 in the worst > > > > case so far), so an alternative would be to specify the interrupt- > > > > parent only, and call irq_create_of_mapping() directly. What solution > > > > would you prefer ? > > > > > > Are the interrupts in a contiguous block in the controller so you can > > > just pass around the controller and a base number? > > > > In two of the three SoCs I need to fix they are. I've just realized that > > in the last one the interrupts are in two contiguous blocks in two > > different parents. I will thus need at least a list of <parent-phandle > > base count>. > > > > Our standard interrupt bindings don't seem to support multiple parents, > > You can actually do it by using a dummy node with interrupt-map and > interrupt-map-mask properties, but it is a pretty ugly solution in my > opinion. > > > is that something that we want to fix or should I go for custom bindings ? > > Yes, I think it is something that we want to fix. Jean-Christophe was going > to propose an alternative to the interrupts property which allows an array > of <phandle interrupt-specifier> tuples, but I've not seen anything yet. Go > ahead and make a proposal.
More work, great :-)
A bit of bikeshedding here, as the "interrupts" property is already used, how should I name the new property ?
> You could try to encode a base+count variant, but honestly I don't think it > would be a good idea because it only would work with a very narrow set of > use cases. Consider if #interrupt-cells was set to 2. Which cell gets > incremented in the range of interrupts specified? Better I think to merely > have an array of fully specified irqs. Support for that property could be > transparently baked into the core interrupt parsing functions.
I agree, I'll try that.
-- Regards,
Laurent Pinchart
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