From mboxrd@z Thu Jan 1 00:00:00 1970 From: grant.likely@linaro.org (Grant Likely) Date: Sat, 27 Jul 2013 23:00:21 -0600 Subject: How to create IRQ mappings in a GPIO driver that doesn't control its IRQ domain ? In-Reply-To: <1681089.qGWOhLKTTo@avalon> References: <1624911.6TtmtVmU1T@avalon> <1408178.cxAUTUGJc5@avalon> <20130725131556.GD9858@sirena.org.uk> <1681089.qGWOhLKTTo@avalon> Message-ID: <20130728050021.4370E3E0A24@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 25 Jul 2013 15:22:29 +0200, Laurent Pinchart wrote: > Hi Mark, > > 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 . 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 tuples, but I've not seen anything yet. Go ahead and make a proposal. 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. g.