In P2020 datasheet, external IRQ is multiplexed with PCI IRQ. How does software configure it so that it can be used as PCI IRQ or external IRQ?
To configure the signals as PCI INTx it is needed to refer to the following documents:
1) Linux Documentation "Generic PCI Host Controller":
sdk/linux.git - Freescale PowerPC Linux Tree
2) "Open Firmware Recommended Practice: Interrupt Mapping":
http://www.firmware.org/1275/practice/imap/imap0_9d.pdf
3) P2020 interrupt mapping DTS from the Linux SDK:
To configure the signals as IRQn it is needed to refer to the AN5121 - Introduction to Device Trees, 5 Interrupts:
http://cache.nxp.com/assets/documents/data/en/application-notes/AN5125.pdf