I'm running a vanilla linux kernel(4.1.13) on the i.mx28 and i would like to add battery backup to my system. When i disconnect the 5V supply, the PMU is using the battery to supply the processor.
When i reconnect the 5V nothing happens. I would like to enable the VBUSVALID interrupt, such that i can start the DC DC converter from the IRQ routine, and log the event. I have written a kernel module which should handle this.
In the PMU application node section 220.127.116.11 the process of enabling the interrupt is described. I do this in the initialization of the kernel module, and when i try to generate my interrupt, either by reconnecting the 5V supply or generating a software interrupt by writing a 1 to the HW_ICOLL_INTERRUPT6[SOFTIRQ] i get the following message on my debugger: unexpected IRQ trap at vector 00.
After this linux halts and restarts.
I suspect that i have overlooked something in the setup of the interrupt.