Messages in this thread | | | Subject | Re: polarity inversion on LS1021a | From | Marc Zyngier <> | Date | Mon, 4 Dec 2017 15:23:30 +0000 |
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Rasmus,
On 04/12/17 15:11, Rasmus Villemoes wrote: > The LS1021A has a standard GIC-400, but allows inverting the polarity of > six external interrupt lines via a certain register, effectively > supporting IRQ_TYPE_LEVEL_LOW and IRQ_TYPE_EDGE_FALLING for those. > > I'm trying to figure out how one would add support for this. The patch > below works but is obviously just meant to help show what I mean, so > please don't comment on all the things that are wrong with it. > > It feels wrong to create a whole new irqchip driver copy-pasting the > entire irg-gic.c, but I can't figure out how and where one could hook > into the existing one. Any pointers on how to do this properly will be > greatly appreciated.
You're missing the usual trick, which is to use a stacked irqchip for these particular interrupts. See drivers/irqchip/irq-mtk-sysirq.c which does exactly that. Bonus point if you make it a generic driver that can be reused by other vendors.
Your patch has been erased in order to protect the innocents ;-).
Thanks,
M. -- Jazz is not dead. It just smells funny...
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