On Fri, Oct 6, 2017 at 7:08 AM, Phil Reid <preid@xxxxxxxxxxxxxxxxx> wrote: > The polarity of the irq could be altered > by additional logic (eg inverters) between the device and irq input device. Marc Zyngier has pointed out that inverters should be modeled using hierarchichal irq domains. You would need to add a new irqchip to invert the line. See this PDF: https://elinux.org/images/8/8c/Zyngier.pdf drivers/irqchips/irq-uniphier-aidet.c supports inversion of IRQs for example. For this it uses irq_domain_create_hierarchy() I guess it would be helpful with a reusable generic "inverter irq chip", that you can just enable and slam into your device tree to tell the system that a line is statically inverted, i.e. non-programmable logic on the board. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
