Documentation/leds/leds-class.rst

11 The class also introduces the optional concept of an LED trigger. A trigger
13 complex. A simple trigger isn't configurable and is designed to slot into
19 parameters and work on a per LED basis. The timer trigger is an example.
20 The timer trigger will periodically change the LED brightness between
24 trigger. However, if you set the brightness value to LED_OFF it will
25 also disable the timer trigger.
28 is chosen (via /sys/class/leds/<device>/trigger). Trigger specific
29 parameters can appear in /sys/class/leds/<device> once a given trigger is
148 the LED_BRIGHT_HW_CHANGED flag is a bug and will trigger a WARN_ON.
185                unique trigger name supported by the LED in hw control
190                 check if the flags passed by the supported trigger can
197                 must be returned, the LED trigger will use software
205                 flags passed from the supported trigger, parse them to
217                 supported trigger.
223                 trigger.
227                 hw control. A trigger might use this to match the
229                 device for the trigger as the source for blinking
231                 (example a netdev trigger configured to blink for a
239 impossibility of supporting each different mode on the supported trigger.
243 A trigger should first check if the hw control API are supported by the LED
244 driver and check if the trigger is supported to verify if hw control is possible,
248 A trigger can use hw_control_get to check if a LED is already in hw control
257 The LED Trigger core cannot be a module as the simple trigger functions
259 compared to the benefits the simple trigger functionality brings. The