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Diffstat (limited to 'Documentation/leds-class.txt')
| -rw-r--r-- | Documentation/leds-class.txt | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/Documentation/leds-class.txt b/Documentation/leds-class.txt index 56757c751d6..18860ad9935 100644 --- a/Documentation/leds-class.txt +++ b/Documentation/leds-class.txt @@ -19,6 +19,12 @@ optimises away. Complex triggers whilst available to all LEDs have LED specific parameters and work on a per LED basis. The timer trigger is an example. +The timer trigger will periodically change the LED brightness between +LED_OFF and the current brightness setting. The "on" and "off" time can +be specified via /sys/class/leds/<device>/delay_{on,off} in milliseconds. +You can change the brightness value of a LED independently of the timer +trigger. However, if you set the brightness value to LED_OFF it will +also disable the timer trigger. You can change triggers in a similar manner to the way an IO scheduler is chosen (via /sys/class/leds/<device>/trigger). Trigger specific @@ -63,9 +69,9 @@ value if it is called with *delay_on==0 && *delay_off==0 parameters. In this case the driver should give back the chosen value through delay_on and delay_off parameters to the leds subsystem. -Any call to the brightness_set() callback function should cancel the -previously programmed hardware blinking function so setting the brightness -to 0 can also cancel the blinking of the LED. +Setting the brightness to zero with brightness_set() callback function +should completely turn off the LED and cancel the previously programmed +hardware blinking function, if any. Known Issues |