1NXP LPC32xx SoC GPIO controller 2 3Required properties: 4- compatible: must be "nxp,lpc3220-gpio" 5- reg: Physical base address and length of the controller's registers. 6- gpio-controller: Marks the device node as a GPIO controller. 7- #gpio-cells: Should be 3: 8 1) bank: 9 0: GPIO P0 10 1: GPIO P1 11 2: GPIO P2 12 3: GPIO P3 13 4: GPI P3 14 5: GPO P3 15 2) pin number 16 3) optional parameters: 17 - bit 0 specifies polarity (0 for normal, 1 for inverted) 18- reg: Index of the GPIO group 19 20Example: 21 22 gpio: gpio@40028000 { 23 compatible = "nxp,lpc3220-gpio"; 24 reg = <0x40028000 0x1000>; 25 gpio-controller; 26 #gpio-cells = <3>; /* bank, pin, flags */ 27 }; 28 29 leds { 30 compatible = "gpio-leds"; 31 32 led0 { 33 gpios = <&gpio 5 1 1>; /* GPO_P3 1, active low */ 34 linux,default-trigger = "heartbeat"; 35 default-state = "off"; 36 }; 37 38 led1 { 39 gpios = <&gpio 5 14 1>; /* GPO_P3 14, active low */ 40 linux,default-trigger = "timer"; 41 default-state = "off"; 42 }; 43 }; 44