Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.
1 LEDs connected to GPIO lines 2 3 Required properties: 4 - compatible : should be "gpio-leds". 5 6 Each LED is represented as a sub-node of the gpio-leds device. Each 7 node's name represents the name of the corresponding LED. 8 9 LED sub-node properties: 10 - gpios : Should specify the LED's GPIO, see "gpios property" in 11 Documentation/devicetree/bindings/gpio/gpio.txt. Active low LEDs should be 12 indicated using flags in the GPIO specifier. 13 - label : (optional) 14 see Documentation/devicetree/bindings/leds/common.txt 15 - linux,default-trigger : (optional) 16 see Documentation/devicetree/bindings/leds/common.txt 17 - default-state: (optional) The initial state of the LED. 18 see Documentation/devicetree/bindings/leds/common.txt 19 - retain-state-suspended: (optional) The suspend state can be retained.Such 20 as charge-led gpio. 21 - retain-state-shutdown: (optional) Retain the state of the LED on shutdown. 22 Useful in BMC systems, for example when the BMC is rebooted while the host 23 remains up. 24 - panic-indicator : (optional) 25 see Documentation/devicetree/bindings/leds/common.txt 26 27 Examples: 28 29 #include <dt-bindings/gpio/gpio.h> 30 31 leds { 32 compatible = "gpio-leds"; 33 hdd { 34 label = "Disk Activity"; 35 gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW>; 36 linux,default-trigger = "disk-activity"; 37 }; 38 39 fault { 40 gpios = <&mcu_pio 1 GPIO_ACTIVE_HIGH>; 41 /* Keep LED on if BIOS detected hardware fault */ 42 default-state = "keep"; 43 }; 44 }; 45 46 run-control { 47 compatible = "gpio-leds"; 48 red { 49 gpios = <&mpc8572 6 GPIO_ACTIVE_HIGH>; 50 default-state = "off"; 51 }; 52 green { 53 gpios = <&mpc8572 7 GPIO_ACTIVE_HIGH>; 54 default-state = "on"; 55 }; 56 }; 57 58 leds { 59 compatible = "gpio-leds"; 60 61 charger-led { 62 gpios = <&gpio1 2 GPIO_ACTIVE_HIGH>; 63 linux,default-trigger = "max8903-charger-charging"; 64 retain-state-suspended; 65 }; 66 };