1* Xtensa built-in Programmable Interrupt Controller (PIC) 2 3Required properties: 4- compatible: Should be "cdns,xtensa-pic". 5- interrupt-controller: Identifies the node as an interrupt controller. 6- #interrupt-cells: The number of cells to define the interrupts. 7 It may be either 1 or 2. 8 When it's 1, the first cell is the internal IRQ number. 9 When it's 2, the first cell is the IRQ number, and the second cell 10 specifies whether it's internal (0) or external (1). 11 Periferals are usually connected to a fixed external IRQ, but for different 12 core variants it may be mapped to different internal IRQ. 13 IRQ sensitivity and priority are fixed for each core variant and may not be 14 changed at runtime. 15 16Examples: 17 pic: pic { 18 compatible = "cdns,xtensa-pic"; 19 /* one cell: internal irq number, 20 * two cells: second cell == 0: internal irq number 21 * second cell == 1: external irq number 22 */ 23 #interrupt-cells = <2>; 24 interrupt-controller; 25 }; 26