Hello everybody,
I am having trouble to use the NXP PCA9539 as an IRQ source on a board
where two of them share the same Interrupt line.
When the PCA9539 starts, interrupts are already enabled. There is also
no way to disable interrupts. This means that both chips pull down the
interrupt line. When the driver gets instantiated for the first chip,
the interrupt line is enabled and an interrupt caused. This causes the
interrupt handler for the first chip to be called, but this does not
reset the interrupt coming from the second chip. Its handler is not
being called as it is still not installed. This means that the interrupt
line will be considered stuck and disabled subsequently.
I think I need to delay the activation of the interrupt source until
both interrupt handlers have been installed. Is it possible to describe
this behavior in the devicetree?
Best regards
Raphael Lisicki
