2014-09-05 13:48 GMT+02:00 Luke Kenneth Casson Leighton lkcl@lkcl.net:
there are two EINT lines on EOMA68. i suggest that one of them be connected to the AXP209, and the other to the STM32F072, although because there are only 2 this leaves some slight issue with the touchpanel to resolve (in linux kernel source, which will need modification).
the problem is this: things like the touchpanel it is fairly essential (because you want to wake up the entire device based on an EINT) to have external interrupt.
one alternative to modifying the linux kernel source is to have a NAND (NOR?) IC multiplexing multiple IRQ lines from various peripheral ICs onto the one EINT line.
another alternative is to wire the AXP209 to the STM32F (on one of its GPIOs, then put that into EINT mode), then have the STM32F software generate a simple GPIO pull-up out to one of the EOMA68 EINTs.
so instead of doing the multiplexing using a NAND (NOR) gate IC, you do it in software (firmware) instead.
then you can do whatever you want, without modifying any linux kernel source.
Thanks.
And, what is your recommendation?
- Headphone detect
What is the INT/IRQ pin here?
Thanks.